DE102007046496A1 - Protection encapsulation manufacturing method for Organic LED, involves executing molding process under influence of heat to form cavity at surface of encapsulation element, where cavity accommodates drying agent - Google Patents

Abstract

The method involves superimposing a plane encapsulation element (1) and a drying agent on top of each other. The drying agent rests against a plane surface (1a) of the encapsulation element at predetermined surface regions. A molding process is executed under heat influence to form a cavity (8) at the plane surface of the encapsulation element, where the cavity accommodates the drying agent. The plane surface is deformed during the molding process. The encapsulation element consists of a glass, a metal or a ceramic. An independent claim is also included for an electronic component with a carrier substrate and a protection encapsulation.

Description

The The invention relates to a method for producing a with at least a cavity provided protective encapsulation for at least one electronic component, in particular for an electro-optical or optoelectronic component such as an organic light emitting diode (OLED, organic light emitting diode). Such and other electronic Components are first on a carrier substrate trained and later covered with a protective encapsulation to prevent the ingress of contaminants from the ambient air, especially moisture to prevent. Depending on the type of electronic component, the carrier substrate remain wholly or partially on the electronic component or Completely or partially removed. As a carrier substrate can For example, semiconductor substrates (also binary, ternary or quaternary substrates, in particular III-V substrates) are used. For optoelectronic or electro-optical applications, in particular transparent Substrates (in the visible or another wavelength range) be used. The the carrier substrate opposite side of the electronic component and the lateral Scope of the component must usually shielded against external influences become. For example, in organic light emitting diodes in the Component penetrating moisture affect the light production and lead to premature aging. But also the efficiency and functionality other electronic components are protected by the intrusion of Moisture or endangered by other foreign substances. All this leads during the actually intended life to quality losses up to the premature Failure.

In The exposed areas of the respective component is usually provided for protection an encapsulation. This consists essentially from a preprocessed and structured on one page Plate made of, for example, a glass, a metal or a ceramic. The pre-structured plate has (depending on the design and number the electronic components) on the device facing Side one or more cavities, this means Cutouts. The recesses or cavities in the pre-structured encapsulation element serve to receive a desiccant, that is one Dry holding agent, and during the life of the electronic component moisture (if necessary. other impurities as well) should be kept away from the electronic component should. The desiccant may be about a physisorbent or a chemisorbent material.

The wells can for example, be located where (in comparable position on the carrier substrate) electronic components are arranged. The cavity and that However, arranged therein desiccant could also in a circulating area be provided of the encapsulation element, which after assembly of the Encapsulation element with the carrier substrate, the Component annular surrounds and in particular by the bond between the encapsulation element and carrier substrate permeated moisture binds.

The Production of the encapsulation element conventionally brings one size Variety of manufacturing steps and also during transport and packaging a large number of further work steps with it. In particular, must conventional for the preparation of the protective encapsulation, first a glass plate or a other areal Encapsulation element are structured (before insertion desiccant) to form the cavities. For this purpose is For example, a mask on the still unstructured encapsulation element (For example, a glass plate) applied and the encapsulation element, for example structured by a sandblast treatment or by an etching. After that the structured encapsulation element is cleaned, with a Protective film provided and finally for the Shipping packed. Elsewhere, the drying agent is produced and in a manner suitable for application to the glass plate, respectively Introduction into the cavities suitable, ready-made. In ready-made form, the drying agent Also packed ready for shipping and possibly even before activated in order to drive off remaining moisture as a result of the manufacturing process (especially for physisorbing desiccants).

The Encapsulation element and the ready-made drying agent after shipping unpacked under clean room conditions and each other applied, whereby the protective encapsulation arises. This one will then to the provided with the at least one electronic component carrier substrate applied. In particular, the protective encapsulation on the carrier substrate glued.

by virtue of the plurality of steps for producing the planar encapsulation element (the back side encloses the electronic component), the drying agent and as well for the separate shipping and re-unpacking during assembly arises so far a high work, time and cost.

It the object of the present invention is to reduce the labor, time and cost of producing a protective encapsulation and with Their reduced electronic components and a simplified To provide manufacturing process.

• – Aufbringen eines flächigen Verkapselungselements und eines Trocknungsmittels aufeinander, wodurch das Trocknungsmittel an vorgegebenen Flächenbereichen einer Oberfläche des Verkapselungselements anliegt, und
• – Durchführen eines Formgebungsschrittes unter Wärmeeinwirkung, wodurch in der Oberfläche des flächigen Verkapselungselements zumindest eine Kavität ausgebildet wird, die das Trocknungsmittel aufnimmt.

This object is achieved according to the invention by a method comprising:

• - Applying a planar encapsulation element and a drying agent to each other, whereby the desiccant is applied to predetermined surface areas of a surface of the encapsulation element, and
• - Performing a shaping step under the action of heat, whereby in the surface of the planar encapsulation element at least one cavity is formed, which receives the desiccant.

According to the invention Applying the drying agent on the flat encapsulation element associated with the structuring of the encapsulation element. Especially According to the invention, the drying agent not in already prefabricated cavities of an already pre-structured Encapsulation element introduced, but the encapsulation element itself is only during the application or structured after the application of the drying agent. This is already uncommon because the desiccant when applied to the encapsulation element is, just those areas covered, which actually structure would, However, due to the overlying desiccant no longer one Sandblasting or a chemical etching are accessible.

According to the invention Structuring not as usual made by a chemical or other destructive external influence, but by a deformation of the encapsulation element, which for this purpose a heat effect undergoes a spatial deformation the material of the encapsulation element (in the simplest case a first still unstructured glass plate) allows or at least facilitates. In the heated Condition according to the invention is a shaping the encapsulation element in which the desiccant partially the material of the encapsulation element displaced and just hereby the cavities arise. However, the formation of the cavities can also be done in the way that the material of the encapsulation element in free spaces between various areas of a desiccant is crowded, for example by liquefaction and / or by pressure in the heated Status.

Compared to the usual Manufacturing processes, the cavities arise only with the introduction of the desiccant in the material of the encapsulation element. In addition, as described above, the drying agent itself to material displacement or shaping the encapsulation element used. After that, the protective encapsulation is complete and can be used as a whole be shipped or mounted, such as on a carrier substrate with one or more electronic components.

Possibly can the heat effect to Reshaping of the plane support element be used at the same time to thermally activate the desiccant (this means to drive out existing production-related moisture and that Desiccant to actively bind moisture). The the effect of heat can also be used to physically the desiccant to transform, for example, to sinter.

Preferably is provided that the surface of the encapsulation element is a planar surface, which in the shaping step under heat is deformed. Unlike traditional manufacturing methods For the first time unstructured, completely flat plates can be made out of, for example Glass, metal or ceramic (or other moisture impermeable material) use without being elaborate Structuring steps by chemical etching or sandblasting required would. Rather, the first flat glass plate in the heated Condition structured by the desiccant itself, in particular deepened locally. Here, the cavities arise only as a result of applying the desiccant and the encapsulation element on each other.

Preferably it is provided that the at least one cavity is formed under additional pressure , whereby the desiccant is pressed into the heated encapsulation element becomes. For example, the planar encapsulation element can be and the desiccant between two pressing tools on each other apply and compress so that the desiccant is there, where it comes into contact with the material of the encapsulation element, this displaces. For this purpose, the drying agent, for example, of a material insist that a higher Melting point or softening point has as the material of flat Encapsulating. It is sufficient even if the desiccant at the applied temperature less viscous as the material of the encapsulation element. However, even with a desiccant with lower melting point the pressing tools be shaped so that by the respective mold and / or the much larger volume the material of the encapsulation element compared to the desiccant this material through the desiccant (and through the desiccant carrying contour of the pressing tool) is displaced.

It is preferably provided that the deformability of the encapsulation element is temporarily increased by the action of heat and that the encapsulation element is cooled again after the formation of the at least one cavity. In particular, it can be provided that the encapsulation element is temporarily put into a flowable state by the action of heat, in which it assumes the shape of a bearing surface of a base. As a result, the planar encapsulation element (for example a glass plate) can also be deformed without external pressure. For example, if the initially unstructured encapsulation element is located in a furnace on a support surface that has previously been covered in places with the desiccant, the material of the encapsulation element in the meltable state lowers due to its own weight into the interstices between adjacent regions covered with desiccant. As a result, gaps between the drying agent are filled, so that the contours of the remaining drying agent at the same time form the inner wall of the cavities.

Preferably it is envisaged that a planar encapsulation element will be used which has a given, uniform layer thickness, and that the layer thickness of the encapsulation element by the shaping step is locally reduced to receive the desiccant. This For example, by material displacement by a desiccant happen, which rests on a flat surface. Likewise, however, can an already structured bearing surface of a base, a Press tool or a punch to be used Desiccant not only on the first level surface of the Apply encapsulation element, but the drying agent also to press into these and thus to form the cavities. As a result, the area Encapsulation element structured or at least restructured.

Preferably is provided that the drying agent with a predetermined uniform layer thickness on the given surface areas of the encapsulation element and that in the shaping step the at least one cavity is formed in the encapsulation element to a depth, which is bigger as the predetermined layer thickness of the drying agent. The surface of the Encapsulation element should be shaped so that the desiccant after the formation of the cavities at least not from the rest surface protrudes from the encapsulation element in the deformed state.

Preferably In particular, the encapsulation element in the heated state so reshaped that the cavities are deeper than the height or the layer thickness of the drying agent, so that the Do not use desiccant up to the opening or mouth the respective cavity enough. This leaves for the later one Mounting a residual volume, in which penetrating moisture on the entire desiccant can spread. Accordingly, it is preferable provided that the drying agent with a predetermined layer thickness on the given surface areas of the encapsulation element is applied and that in the shaping step the at least one cavity is formed in the encapsulation elements to a depth, which is bigger as the predetermined layer thickness of the drying agent. alternative may also be provided that in the shaping step the at least one cavity is formed to a depth in the encapsulation element, which is just as big as the predetermined layer thickness of the drying agent. In the latter In the case, the drying agent extends to the outside of the encapsulation element in the deformed state zoom.

Preferably it is provided that the drying agent on the encapsulation element is printed. this makes possible a very simple application, for example with the aid of a printing stamp or a printmask. The desiccant can either by the towering Surface areas of the Plunger itself be applied or alternatively, such as as in a screen printing process, through openings of a printing stamp be applied to the encapsulation element.

alternative it can be provided that the drying agent in the form of a or several moldings is applied to the encapsulation element. The moldings or fittings of desiccant can, for example from a plane Be raw material preformed moldings, which is a uniform, predetermined Have layer thickness. these can then in a defined, for example, matrix-shaped arrangement on or on be positioned the encapsulation element.

Regarding the shaping step may be provided that when forming the at least one cavity one to the surface the encapsulation element opposite further surface of the Encapsulation element domed locally becomes. This local arch the back Verkapselungsoberfläche may in particular be done in those places where the front of the drying agent is pressed.

The surface area covered by the desiccant may, for example, correspond to the cross-sectional area of an electronic, for example optoelectronic or electro-optical component, or may circulate an outer circumference of one or more electronic components. in particular Especially in the latter case, complete protection against moisture-related premature aging is achieved, even with very large-area components, since moisture diffuses mostly along the adhesive surface between the finished encapsulation element and the carrier substrate of the electronic component.

Preferably it is provided that the at least one cavity is formed by at least a molding of desiccant during or after exposure to heat is pressed into the material of the encapsulation element. Thus eliminates the conventionally provided Step of etching or sandblasting to form the one or more cavities; instead the cavities become simultaneously with the bringing together of desiccant and encapsulation element educated. The mold thus obtained remains after cooling the permanently preserved encapsulation element and eliminates the separate shipping of desiccant and encapsulation element and the subsequent Introducing the drying agent into the planar encapsulation element, before it is mounted on the electronic component.

Preferably it is provided that the desiccant on an upwardly facing surface of the Encapsulation element is applied. This requires the desiccant at first only can be hung up and then after the encapsulation element was heated, are pressed into the top. Likewise, that can Desiccant on an already heated encapsulation element, which is thus already deformable, be pressed.

alternative it is envisaged that the encapsulation element and the desiccant be applied to each other by the desiccant to specified surface areas a pad is applied and the encapsulation element on the applied with the desiccant pad is applied. at this embodiment the drying agent is placed under the encapsulation element, so on the pad first the drying agent and then placed on the encapsulation element becomes. In this embodiment does not necessarily need the desiccant in the encapsulation element pushed to become, but the free spaces between the areas of desiccant on the surface can through that into a flowable state be brought filled material of the encapsulation element. For example, the encapsulation element is first applied and then through Heat made flowable.

Accordingly is preferably provided that the encapsulation element from above the applied with the desiccant pad is applied and the material of the Verkap selungselements in the heated state with surface areas the backing which is not covered with the desiccant, is brought into contact.

Preferably is provided that to be covered with the desiccant Pad is a plunger that pushes the desiccant onto the encapsulation element imprints. Thus, one and the same tool surface for Holding the drying agent in a predefined position (for example in the form of a matrix-shaped Arrangement of a plurality of areas or moldings of desiccant) and used for pressing, printing or at least applying the drying agent become.

Preferably can also be provided that with the desiccant to Covering pad is a die, which is the drying agent in the heated Encapsulation element pressed into it. The pressing process can be during or after heating occur. In particular, a printing and pressing in of the Drying agent in the encapsulation also done from below.

provided be that the pad has a flat bearing surface on which the drying agent is applied. This cavities are formed, the exact the shape and the thickness of the drying agent correspond.

alternative it can be provided that the pad has a bearing surface, has the projections, which are covered with the desiccant. In this embodiment can in particular cavities which are deeper than it is given the layer thickness the desiccant would be required. Thus, protective encapsulations can be formed where there is a certain distance between the ones to be encapsulated Components and areas of desiccant at the bottom of the cavities consists. This allows moisture to penetrate first within the volume of the respective cavity over the said cross sectional area of the cavity distribute and thus in contact with the complete top of the desiccant to step. This will provide even more effective protection against damage to the Achieved device. For this purpose, the drying agent does not in the wells, but on the projections of the support surface of the Pad applied.

It is preferably provided that the encapsulation element consists of a glass, in particular of a float glass. However, the encapsulation element can also be made of another moisture-impermeable material, at For example, from a metal or a ceramic. Furthermore, the encapsulation element may also have a multilayer structure, for example made of a plastic and an additional, moisture-impermeable layer.

Preferably is provided that the encapsulation element by the heat to about a softening temperature or above a melting temperature heated becomes. In particular, it can be provided that the encapsulation element made of a glass (or of a metal or a ceramic) and that the encapsulation element is heated to a temperature which between 200 ° C and 2000 ° C lies. It is not necessarily, for example, as in the case of a glass required that a melting temperature reached and exceeded becomes. It may also be sufficient, only a softening temperature To exceed, in which the respective material (in particular glass) of the encapsulation element at least with the help of an additional one Pressure action is deformable.

According to one preferred embodiment provided that the drying agent by the action of heat is activated at the same time. Of these, in particular are physisorbierende Drying agents affected, which are heated before use, already bound, possibly production-related remove remaining moisture and thus the drying agent fit for use close. Thus omitted an additional heat treatment for the Activate the desiccant or for heating the material of the flat Encapsulating. Thus, the Process steps of heating the encapsulation element, the Introducing the desiccant into the wells (which are conventionally separate take place) and the activation of the drying agent to a single Process step are summarized.

Preferably can also be provided that the drying agent through the the effect of heat is sintered at the same time. Here, the drying agent still needs not in its final state to be present when it touches the surface of the encapsulation element is applied, but can during the heat effect in the final Condition are transferred. Furthermore can the heat effect be exploited in particular, that the drying agent of Beginning with the respective contact surfaces of the material of the encapsulation element is brought into close contact. This will also make a better Adhesion between the drying agent and the material of the encapsulation element in the area of the cavity achieved as if the desiccant as conventional only later in the cavity is introduced and there, for example, only the bottom of the cavity in solid Contact is brought. In particular, the drying agent may during the simultaneous warming desiccant and encapsulation material also on the side surfaces respectively Bake at lateral areas of the wall of the cavity.

Preferably it is envisaged that the desiccant on an unstructured Surface of the Encapsulation element is applied. This embodiment is with a considerable saving in labor, time and cost connected, as the conventional always necessary, for example, chemically or mechanically performed structuring the encapsulation element completely eliminated. It Masking steps to protect against structuring are also eliminated arising impact to be protected Surface areas.

Preferably it is envisaged that the drying agent used is a chemisorbing or physisorbierend material is used. For example, can as the chemisorbent material, a metal oxide, for example barium oxide be used. As a physisorbierendes material is for example Zeolite or silica gel. In particular, such drying agents be used, which does not shield from the normal outside air require a shielding gas until it is finally replaced by the encapsulation of the Component to be included.

Basically needs that for the formation of the cavities used material of the drying agent is not completely out Desiccant to exist, but this material can as well contain further constituents which, for example, for solidification, hardening or for better bonding to the material of the encapsulation element serve. Furthermore, any other additive in the Be contained desiccant. The drying agent, however, must at least in parts (preferably more than 50 percent, in particular to more than 75 percent) contain a material containing moisture binds.

It may be provided that the drying agent is applied to a plurality of surface areas of the surface of the encapsulation element, which form a matrix-shaped arrangement on the surface of the encapsulation element. In this embodiment, in particular, a plurality of regions of the surface of the encapsulation element can be formed into cavities in order to encapsulate a multiplicity of electronic components when the reshaped encapsulation element is connected to the carrier substrate with the components. Alternatively, however, an area of the environment of one or more (or even all Licher) components are transformed into a single cavity. Such a cavity may, for example, surround a single, several or all components annularly or in another way. In this case, the area covered by the drying agent and recessed into a cavity (for example an edge area of the encapsulation element) circulates the base area on the surface of the encapsulation element that corresponds to the base area of the protective building elements.

Preferably it is envisaged that a protective encapsulation for an electro-optical or optoelectronic component, in particular for a light-emitting diode, an organic LED, a display or a surface light source manufactured becomes. However, you can any other components, in particular those on a Substrate, for example, a semiconductor substrate are to be formed, encapsulated using the protective encapsulation according to the invention become.

The underlying object is further solved by a protective encapsulation for at least one electronic component with a planar encapsulation element, on at least one side a structured surface with at least one cavity has, and a desiccant, in the at least one cavity is arranged.

Preferably it is envisaged that the protective encapsulation according to one of this Registration described method is made.

The Production method according to the invention allows for the first time the use of even thinner Schutzverkapselungen with a maximum layer thickness of less than 0.5 mm, as the areas of the encapsulation element, which reduced one below the cavities Layer thickness besithen, from the beginning by the drying agent reinforced which contributes to mechanical stability and better to mechanical Damage, protects against breakage during transport, for example.

Preferably In particular, it is provided that the encapsulation element of the protective encapsulation a maximum layer thickness of less than 0.5 mm, preferably between 0.5 and 0.2 mm. The inventive method thus allows the use of thinner Encapsulation plates, for example glass plates or ceramic plates, for the production of encapsulations of electronic components. By this reduction in minimum layer thickness becomes a Material savings and thus achieved cost savings.

Preferably is provided that the drying agent to the ground and to the Side wall of the at least one cavity is thermally festgebacken. Since the desiccant not later, but already at Training and the formation of the cavities with the material of the encapsulation element in touch comes (and when heated is), greater liability arises also on the side walls or the lateral areas of the respective cavity, as if as usual the drying agent later to the bottom of the cavity is pressed at room temperature.

Preferably it is provided that the side of the planar encapsulation element, on the at least one cavity and the desiccant are disposed, an exposed surface of Form protective encapsulation. Thus, with the inventive method a protective encapsulation are produced in whose cavities the Desiccant is more firmly bound than in the case of a subsequent Attachment of the drying agent. With this protective encapsulation can in particular opto-electronic and electro-optical components, for example light emitting diodes (in particular organic light emitting diodes) Area light sources, Encapsulated displays or any other electronic components become.

The Invention will be explained below with reference to the figures. It demonstrate:

1 a schematic representation of an encapsulated electronic component with a plurality of electronic components 3 .

2 a schematic representation of an unencapsulated electronic component and a surface encapsulation element with initially unstructured surfaces,

the 3 to 7 Method steps of a first embodiment of a manufacturing method according to the invention,

the 8th to 10 Method steps of a second embodiment of a manufacturing method according to the invention,

the 11 to 14 Method steps of a third embodiment of a manufacturing method according to the invention,

the 15 to 18 Method steps of a fourth embodiment of a manufacturing method according to the invention,

the 19 an embodiment of an electronic component with exactly one electronic component,

20 another embodiment of a electronic component with a variety of electronic components,

21 a conventional process for the manufacture and assembly of a protective encapsulation and

22 An embodiment of a process according to the invention enabled process for the production and installation of a protective encapsulation.

1 shows a schematic cross-sectional view of an electronic component 20 , the a plurality of electronic, in particular optoelectronic or elekt rooptischen components 3 which is on a carrier substrate 4 are arranged. The electronic component 20 has an encapsulation 10 consisting of a substantially planar encapsulation element 1 with two parallel main surfaces and a desiccant 5 is formed. The the carrier substrate 3 facing surface of the encapsulation element 1 is a structured surface; In particular, it has a large number of cavities 8th (or at least one cavity 8th ). In all or at least some of the cavities 8th is a drying agent 5 arranged, preferably at the bottom of the respective cavity. The desiccant prevents damage to the electronic components 3 by moisture, along the interface between the carrier substrate 3 and the encapsulation element 1 can penetrate. Also, moisture may diffuse out of the adhesive used, for example, as long as the adhesive is not fully cured and dry. Likewise, even during the usually several years of operation, small amounts of moisture can pass through the adhesive layer or along the interface between the carrier substrate and the encapsulation element to the components 3 penetrate. That in the cavities 8th intended drying agent 5 absorbs this moisture, in particular by chemisorption or physisorption, and thereby prevents damage to the components 3 ,

2 schematically shows the still unencapsulated electronic component with on one side of the carrier substrate 3 arranged electronic components 4 , Furthermore, a planar encapsulation element 1 illustrated, the lateral dimensions, for example, substantially to those of the carrier substrate 3 can match; At least the encapsulation element is intended to encapsulate the bases of all the electronic components 4 cover. The later in the finished component the carrier substrate facing surface 1a is initially still unstructured, but with (for example, several) cavities 8th be provided (of which in 2 a dashed line is indicated) which receive the desiccant and the electronic components 4 enclose. Conventionally, the cavities are made either by a sandblasting process or by a chemical etch, each requiring masking steps. The present embodiments of the method according to the invention considerably simplify the production of an encapsulation element having a structured surface which has one or more cavities.

The 3 to 7 show method steps of a first embodiment of a method according to the invention. According to 3 become a planar encapsulation element 1 and a drying agent 5 arranged one above the other. The drying agent 5 is on predetermined surface areas 11 a (preferably initially flat) surface 1a of the encapsulation element 1 arranged. For example, the desiccant may be on an upwardly facing surface 1a be applied, printed or otherwise applied. The initially planar encapsulation element 1 has a predetermined layer thickness D. Further, the drying agent 5 be applied with a uniform, predetermined layer thickness d1. For example, the drying agent 5 in the form of one or more moldings 6 , each having a preferably identical layer thickness d1, on the encapsulation element 1 be hung up. Alternatively, the drying agent can also be printed with a predetermined layer thickness d1, for example if it is present as a printing material.

4 shows the arrangement of encapsulation element 1 and desiccant 5 after being applied to each other. The drying agent 5 protrudes completely from the surface 1a of the encapsulation element 1 out. According to the invention, therefore, a shaping step is used in which the surface 1a is reformed to form one or more cavities.

For this purpose, the material of the encapsulation element is under heat 1 deformed, as shown in the following figures. It should be noted, however, that alternatively, the encapsulation element 1 warmed up first and then afterwards (when brought into contact with the desiccant 5 ) can be deformed.

According to 5 will the in 4 shown arrangement of encapsulation element 1 and desiccant 5 between two molds 7 compressed. A first mold, for example, a pad 12 be. The pressing process of this shaping step 15 ( 6 ) takes place under the action of heat W. For example, the molds 17 can be heated, or the heat effect in another way, for example by the surrounding atmosphere, approximately in one Oven, done. For example, the temperature is raised to a temperature between 200 ° C and 2000 ° C which corresponds, for example, to a melting temperature or softening temperature of the material of the encapsulation element (these temperature related characteristics may also be combined with the below-mentioned embodiments of the process of the invention ). According to 5 become the molds 17 Pressed together under pressure p, causing the in 6 shown arrangement results.

According to 6 the drying agent was incorporated into the material of the encapsulation element 1 pressed in, whereby the previously unstructured (for example, overhead) surface 1a to a structured surface 2 was reshaped, which now has one or more cavities 8th having. The cavities 8th are thus not prestructured by additional processing steps before the drying agent is introduced. Instead, the cavities are formed by pushing in the desiccant 5 educated. The initial layer thickness D of the encapsulation element ( 5 ) is thus locally reduced, at least by the layer thickness d1 of the drying agent. The heat W (and optionally, as in this embodiment, the pressure) needs to be applied only temporarily.

7 shows the protective encapsulation obtained in this way 10 , their encapsulation element 1 on at least one side a structured surface 2 with at least one cavity 8th having. The drying agent is in the cavities 5 so arranged that it does not have the outermost areas of the textured surface 2 protrudes and thus completely disposed within the cavities.

The 8th to 10 show a further embodiment of a method according to the invention.

According to 8th becomes the drying agent 5 as a pressure mass 19 (that is, similar to a printing ink) on the encapsulation element 1 applied. For this example, one of the two molds 17 as a printing stamp 16 ausgebil det, for example, projections 18 may comprise, with a film of the drying agent 5 are covered. Of course, alternative printing methods can also be used, for example screen printing methods. In these methods, a printing mask is used, wherein the drying agent 5 or the mass to be printed just in the openings of the print mask on the element to be printed, here on the encapsulation element 1 , is applied. 8th also shows an embodiment in which the encapsulation element 1 already warmed up (heat W), it with the desiccant 5 is brought into contact. Thus, the order of applying encapsulant and desiccant to each other and performing the molding step 15 variable; In particular, both steps can be carried out simultaneously. Further, the heating of the encapsulation member enabling the molding step may be performed even before the encapsulation member and the desiccant are brought into contact with each other.

According to 8th becomes the pressure mass 19 not just printed on the encapsulation element 1 stick to it, but the pressure mass 19 is additionally under pressure p (with simultaneous heat W or at least in already preheated encapsulation 1 ) in the encapsulation element 1 pushed. The encapsulation element is thus not only printed from the outside, but deformed.

This creates the arrangement according to 9 in which the previously flat surface 1a is now structured and cavities 8th by the desiccant pushed in 5 , optionally (as in 9 shown) additionally by projections 18 in the bearing surface of the plunger 16 originate.

10 finally shows the finished protective encapsulation 10 with the encapsulation element 1 and the desiccant 5 that in cavities 8th a surface under heat (and preferably additional pressure) structured surface 2 are arranged. As in 10 recognizable, own the cavities 8th a depth that is greater than the layer thickness of the introduced desiccant 5 , Thus, the side wall protrudes 9 the respective cavities on the drying agent 5 and provides space for projecting portions of the electronic components to be encapsulated of the electronic component. The structured surface 2 opposite surface 1b of the encapsulation element 1 can remain unstructured, but it can also be deformed, for example, be domed locally - depending on the shape of the support surface of the respective mold 17 (for example, below in 9 ).

The 11 to 14 show a further embodiment of a method according to the invention. According to 11 First, the drying agent 5 on a pad 12 arranged. The underlay 12 For example, it may be a press mold, but it need not be used for pressing, but may also be a pad for an exclusively under heat taking place melting or flow process in which the encapsulating 1 in the heated state, due to its own weight alone, begins to reshape. According to 11 the drying agent is applied to predetermined surface areas 14 the bearing surface 13 the underlay 12 applied. These surface areas 14 For example, they may correspond to those surface areas in which cavities in the encapsulation element 1 are to be trained.

The drying agent 5 For example, in the form of one or more moldings 6 be arranged on the substrate, for example in the form of a matrix-shaped arrangement of several moldings. The molded parts may for example have a uniform layer thickness d1. They may, for example, have been punched out of a flat raw mass or otherwise separated out and then provided in relative positions relative to one another on the base 12 to be ordered. Alternatively, the drying agent 5 also in the form of a pressure mass 19 (in the 11 to 14 not explicitly shown) on the pad 12 be applied.

According to 11 is on the arrangement of pad 12 and desiccant 5 a still unstructured encapsulation element 1 applied, for example, applied from above. This results in the arrangement according to 12 , in which the initially undeformed encapsulation element 1 on one or more areas of desiccant 5 which, in turn, passes through the underlay 12 being held. At the latest, one begins with the application of the heat action W, whereby the temperature T is increased to the material of the encapsulation element 1 in a flowable, deformable state in which it changes its shape due to its own weight (or optionally with additional pressure) and in particular the spaces between adjacent areas of desiccant 5 fills.

13 shows the result of the shaping step, which causes the material of the encapsulation element brought into the flowable state 1 evenly over the entire contact surface of the base 12 distributed and thus the bearing surface 12 between those with desiccant 5 covered areas (ie the surface of the pad) contacted. Thus, the lower surface became 1a ( 12 ) of the encapsulation element 1 reshaped and now has cavities, each on the support surface 13 the underlying drying agent 5 surround and enclose laterally.

14 shows the encapsulation element produced in this way 10 with the structured surface (as shown below pointing downwards) 2 in which the drying agent 5 in cavities 8th is included. The opposite surface 1b can either be flat or locally domed, wavy or otherwise deformed, as in 14 indicated by dashed lines. For this purpose, wavy or otherwise uneven bearing surfaces can be used, for example, the breaking strength of the encapsulation element to be produced 10 to increase material savings at the same time.

The 15 to 18 show a further embodiment of a method according to the invention. According to 15 will (as in 11 ) first the drying agent 5 on a pad 12 applied and then the flat encapsulation element 1 placed on this arrangement of pad and desiccant. The underlay 12 can also be a mold 17 be that (see 16 and 17 ) under additional pressure with another mold 17 is compressed. In addition, the pad or the mold at the same time a plunger 16 which is used to selectively on predetermined surface areas of a surface 1a of the encapsulation element 1 the drying agent 5 be printed. So shows 15 in that the drying agent 5 for example, on projections 18 the bearing surface 13 is applied; either in the form of a pressure mass 19 or in the form of one or more moldings 6 , In this arrangement, finally, the planar encapsulation element 1 hung up.

According to 16 Then, the heat W or a heat treatment is performed, in which the temperature of the encapsulation element 1 is increased.

Can be used as the material of the encapsulation element 1 may, as well as in all other embodiments of this application, be about a glass, for example a float glass, but also a ceramic or a metal or a multilayer material with at least one water-impermeable layer. In the case of a glass, the temperature T can be increased above a softening temperature or a melting temperature of the glass to the material of the encapsulation element 1 to bring into the flowable state. According to 16 become the desiccant and the encapsulation element 1 using two or more dies 17 compressed, causing the encapsulation element 1 is deformed and due to the increase in temperature (and preferably also the pressure action) assumes a shape which by the bearing surfaces of both press molds 17 is predetermined.

17 shows as a result of this shaping step that the material of the Verkapse development elements 1 the entire contact surface 13 (or outer surface) of the lower die 17 covered and thus the spaces between adjacent protrusions 18 ( 15 ) completely. This results in cavities 8th , which each include the desiccant and which are deeper than the layer thickness of the desiccant 5 equivalent.

18 shows the finished protective encapsulation 10 after cooling the material of the encapsulation element 1 , In the bottom, textured surface 2 are the cavities 8th arranged, preferably a floor 17 and a side wall 9 have. The drying agent 5 has a layer thickness d1 which is smaller than the depth of the cavities 8th , At the bottom of the cavities 8th Thus, the original layer thickness of the encapsulation element was local except for a reduced layer thickness d2 of the encapsulation element 1 reduced. The original layer thickness D of the encapsulation element 1 is preferably more than the layer thickness d1 of the drying agent during the forming 5 reduced. This leaves enough scope for receiving the respective electronic component.

19 shows an embodiment of an electronic component 20 , for example, exactly one electronic component 4 having. The electronic component may, for example, be a light-emitting diode, in particular an organic light-emitting diode, but alternatively any desired electro-optical or opto-electronic component. In particular, come as electronic components light emitting diodes, screens, displays, area lights or photovoltaic elements into consideration. According to 19 owns the electronic component 20 a carrier substrate for the electronic component 4 , The latter comprises in particular a first electrode 4a , a second electrode 4b and a layer stack therebetween 4c which is in particular an active layer stack. The layer stack serves, for example, for the conversion of electrical energy into electromagnetic radiation or vice versa.

The electronic component 20 also has a protective encapsulation 10 coming from the encapsulation element 1 and the desiccant 5 is formed. The encapsulation element 1 has at least one cavity 8th that is, a depression in the carrier substrate 3 facing surface. In the cavity 8th are the desiccant as well as an area of the electronic component 4 arranged. Basically, under the cavity 8th any recess in the surface, in particular major surface of a flat encapsulation element understood. The encapsulation element may in particular be a glass plate, metal plate, ceramic plate or a multilayer arrangement with at least one water-impermeable layer. The structured surface of the encapsulation element 1 (in 19 the lower surface) is outside the cavities 8th on the carrier substrate 3 attached, for example using an adhesive 21 , This forms a thin adhesive layer, which may still contain some residual moisture due to the production. This is done by the desiccant 5 bound and therefore does not get into the electronic component 4 , Likewise, during the service life of the component 20 (or during the intended lifetime of typically many years) moisture between the carrier substrate 3 and the encapsulation 10 into the cavity 8th penetrates through the desiccant 5 bound. This prevents premature aging and deterioration of the electronic component 20 due to the component 4 even ingress of moisture. For example, insulating transparent oxides (ITOs, insulating transparent oxides) may be used as the carrier substrate, in particular in the case of optoelectronic components in which the carrier substrate should be permeable to the emitted radiation wavelength.

As a drying agent 5 In principle, all chemisorbierenden or physisorbierenden materials into consideration, for example zeolite or barium oxide, to name just a few examples. Unlike a conventional electronic component, as in 19 recognizable, the drying agent 5 not only with the floor area 7 the at least one cavity 8th firmly connected, but is also in firm contact with the side wall 9 the cavities 8th , Furthermore, owing to the shaping or deformation of the encapsulation element that takes place under the effect of heat 1 the drying agent 5 firmly to the inner wall, ie both to the ground 7 as well as on the side wall 9 the respective cavity 8th baked and therefore adheres better to the material of the encapsulation element than in the conventional subsequent introduction of the drying agent 5 in previously formed cavities.

In addition, since the cavities only when contacting the encapsulation element 1 with the drying agent 5 be formed, according to the invention eliminates manufacturing steps for the separate transport and packaging of desiccant and encapsulation element and manufacturing steps for the prior structuring of the encapsulation element for forming the cavities.

20 shows a further embodiment of an electronic component 20 , According to 20 has the electronic component 20 a plurality of electronic components 4 on, for example, a matrix-shaped arrangement M on the base of the carrier substrate 3 can form. The electronic component 20 has a protective encapsulation 10 , its encapsulation element 1 since Lich in the lateral direction over the electronic components 4 extends in the field of electronic components 4 a cavity 8th' (with or without desiccant) and also an additional, the at least one component 4 surrounding, but not covering outer cavity 8th comprising, at least partially, with desiccant 5 is filled. On the base of the carrier substrate 3 or of the encapsulation element 1 circumscribes this additional cavity 8th one or preferably all electronic components 4 and thereby prevents moisture-related damage that could be caused by penetrating moisture from the edge of the interface between the carrier substrate and the encapsulation element. Thus, according to 20 not every cavity (especially not the cavity 8th' for receiving the electronic components 4 ) with a drying agent 5 to be provided, but it is sufficient if an outside circumferential cavity 8th with a drying agent 5 is provided. These outer, around the perimeter less or all electronic components 4 extending cavity 8th with the drying agent 5 can be shaped annular, for example. It can also be rectangular or otherwise circulate the components.

In the in 20 shown cross-sectional view, which shows a sectional area perpendicular through the carrier substrate and the encapsulation element, each left and right of the matrix-shaped arrangement M is a cross section of the circumferential cavity 8th recognizable. This cavity is at least partially with the desiccant 5 filled.

Incidentally, instead of the matrix-shaped arrangement M of a plurality of components 4 be provided any other arrangement of components or even a single component. Furthermore, instead of the cavity 8th' that covers and encloses all components, including a plurality of cavities 8th' be provided, each covering one or some of the components and include.

Since in the method according to the invention according to one of the embodiments of the application disclosed here, the drying agent need not be separately formed, transported, packaged and handled before it is introduced into the cavities, in particular, structures revolving annularly or otherwise around the outer circumference of the electronic components be made easier from drying agents; already from the beginning after printing or otherwise applying the drying agent on the flat encapsulation element 1 the encapsulation element forms a stable base for protecting the desiccant 5 ,

21 shows a conventional procedure for producing and mounting a protective encapsulation. First, an unstructured encapsulation member such as a glass plate (for example, a float glass), a metal plate, or a ceramic plate is provided. Subsequently, the still unstructured plate (or the still unstructured, flat encapsulation element) is structured. For this purpose, a mask layer is usually applied to the encapsulation element and then the mask layer is first structured itself. Subsequently, the encapsulation element is processed through the structured mask layer, for example by sandblasting or by chemical etching. As a result, cavities are formed on predefined surface areas of the encapsulation element. Subsequently, the mask layer is removed and the structured encapsulation element is cleaned and packaged ready for shipment.

Separately of which the drying agent is provided and then in one for the shipping suitable manner. Providing the Desiccant can, for example, the extrusion of a mass of desiccant to form a flat strip of desiccant mass to obtain. However, the mass of desiccant is in this Form not yet suitable to later - the user in the encapsulation of an electronic component - on the structured encapsulation element to be applied, because the the mass of desiccant is not yet structured itself.

Therefore the desiccant is first itself (as part of the packaging) structured. For example, can a strip of desiccant mass on a carrier foil be applied and then subjected to a stamping process, the certain surface areas of the drying agent (if necessary. With the carrier film) punched out and thus a defined, for example, matrix-shaped arrangement of moldings leaves from drying mass, the with the help of the carrier foil later can be applied to a structured encapsulation element.

The Arrangement of carrier foil and desiccant is then packaged and sent to the user shipped.

There, the encapsulation element and the drying agent are each unpacked, optionally cleaned and spent in a moisture-free atmosphere (for example in a glove box). There, the drying agent (or the film with the desiccant disposed thereon) is then applied to the structured encapsulation element with the cavities. In this case, the desiccant ideally passes in register exactly in the cavities and can in particular be pressed onto the bottom of the cavities. The lateral dimensions of the moldings of desiccant correspond approximately to the lateral dimensions of the cavities. However, due to certain tolerances, the lateral dimensions of the desiccant moldings will be slightly less than the lateral dimensions of the cavities. Thus, the desiccant will have a slight distance from the side wall of the cavity and be pressed only on the bottom of the cavity. Due to the action of pressure, the desiccant must then adhere to the encapsulation element.

The in this way finished at the user protective encapsulation will follow on the carrier substrate applied with the at least one electronic component, whereby an encapsulated component is created.

Of the separate shipping of encapsulation element and desiccant is in this approach, inter alia, due to the fact that the desiccant just before encapsulation of the electronic Component in the cavities the encapsulation element is introduced and until then separately handled and shipped from the structured encapsulation element becomes. Furthermore, it is disadvantageous that initially complex processing steps to structure the first unstructured encapsulation element are required. adversely is also that, where appropriate, that already activated and at the same time pre-fabricated drying agents during the entire transport route must be protected from penetrating moisture.

22 shows an example of a procedure enabled by the present invention. First encapsulation element and the drying agent are provided, wherein the encapsulation element is still unstructured. The desiccant is applied to the (unstructured) encapsulation element. For this purpose, the drying agent is provided in structured form, for example in the form of a plurality of moldings of drying agent, which are arranged in a predetermined matrix-shaped arrangement relative to each other, or in the form of a mass of drying agent, by a printing operation, for example by a screen printing method or by another printing method, is printed directly on the unstructured encapsulation element. The encapsulation element provided with the desiccant is subsequently or already subjected to a shaping step in which, under the action of heat (and optionally under additional pressure), the encapsulation element is deformed in such a way that cavities surround the desiccant in those surface regions in which the desiccant rests or rests arise. Thus, no separate mask layer is required for patterning the encapsulation element. The action of heat can take place, for example, in a furnace in which the encapsulation element is heated, for example, on a base, between two press molds or on another support surface. In particular, in the heated state of the encapsulation element, the desiccant can be pressed into the mass of the encapsulation element. Likewise, any other method of the embodiments mentioned in this application can be used.

Finally, the structured encapsulation element is removed from the oven and forms after cooling the finished protective encapsulation 10 , which is then sent to the user. There, it is applied to the carrier substrate with the at least one electronic component, optionally after optional repeated, brief heating to activate the desiccant. This creates the encapsulated electronic component.

The Applying the finished protective encapsulation to the carrier substrate in turn can be done with the help of an adhesive.

in the Comparison with the conventional one Process flow is a significantly smaller number of work steps required. Thus, time and cost to reduce Production of a protective encapsulation prepared according to the invention and the encapsulated electronic component.

Claims (35)

Method for producing a with at least one cavity ( 8th ) provided protective encapsulation ( 10 ) for at least one electronic component ( 20 ), the method comprising: - applying a planar encapsulation element ( 1 ) and a drying agent ( 5 ), whereby the desiccant ( 5 ) at predetermined surface areas ( 11 ) of a surface ( 1a ) of the encapsulation element ( 1 ), and - performing a shaping step ( 15 ) under heat (W), whereby at the surface ( 1a ) of the planar encapsulation element ( 1 ) at least one cavity ( 8th ) is formed, the drying agent ( 5 ). Method according to claim 1, characterized in that the surface ( 1a ) of the encapsulation element ( 1 ) is a planar surface which is at the forming step ( 15 ) is deformed by the heat action (W). Method according to claim 1 or 2, characterized in that the at least one cavity ( 8th ) is formed under additional pressure (p), whereby the drying agent ( 5 ) into the heated encapsulation element ( 1 ) is pressed into it. Method according to one of claims 1 to 3, characterized in that by the heat action (W), the deformability of the material of the encapsulation element ( 1 ) is temporarily increased and that the material of the encapsulation element ( 1 ) after forming the at least one cavity ( 8th ) is cooled again. Method according to Claim 4, characterized in that the encapsulation element ( 1 ) is temporarily rendered into a flowable state by the action of heat (W), in which it takes the form of a bearing surface ( 13 ) a pad ( 12 ). Method according to one of claims 1 to 5, characterized in that a planar encapsulation element ( 1 ), which has a predetermined, uniform layer thickness (D), and the layer thickness (D) of the encapsulation element ( 1 ) by the shaping step ( 15 ) for forming the at least one cavity ( 8th ) is reduced locally. Method according to one of claims 1 to 6, characterized in that the drying agent ( 5 ) with a predetermined layer thickness (d1) on the predetermined surface areas ( 11 ) of the encapsulation element ( 1 ) is applied and that in the shaping step ( 15 ) the at least one cavity ( 8th ) to a depth in the encapsulation element ( 1 ) is formed, which is greater than the predetermined layer thickness (d1) of the drying agent ( 5 ). Method according to one of claims 1 to 6, characterized in that the drying agent ( 5 ) with a predetermined layer thickness (d1) on the predetermined surface areas ( 11 ) of the encapsulation element ( 1 ) and that in the molding step ( 15 ) the at least one cavity ( 8th ) to a depth in the encapsulation element ( 1 ) is formed, which is the same size as the predetermined layer thickness (d1) of the drying agent ( 5 ). Method according to one of claims 1 to 8, characterized in that the drying agent ( 5 ) on the encapsulation element ( 1 ) is printed. Method according to one of claims 1 to 8, characterized in that the drying agent in the form of one or more moldings ( 6 ) on the encapsulation element ( 1 ) is applied. A method according to claim 10, characterized in that the at least one molded part ( 6 ) of the drying agent ( 5 ) is a preformed from a sheet raw material molding having a uniform, predetermined layer thickness (d1). Method according to one of claims 1 to 11, characterized in that when forming the at least one cavity ( 8th ) one to the surface ( 1a ) of the encapsulation element ( 1 ) opposite further surface ( 1b ) of the encapsulation element ( 1 ) is domed locally. Method according to one of claims 10 to 12, characterized in that the at least one cavity ( 8th ) is formed by the at least one molded part ( 6 ) of the drying agent ( 5 ) during or after the action of heat (W) in the material of the encapsulation element ( 1 ) is pressed. Method according to one of claims 1 to 13, characterized in that the drying agent ( 5 ) on an upwardly facing surface ( 1a ) of the encapsulation element ( 1 ) is applied. Method according to one of claims 1 to 13, characterized in that the encapsulation element ( 1 ) and the drying agent ( 5 ) are applied to each other by the desiccant ( 5 ) to predetermined surface areas ( 14 ) of the bearing surface ( 13 ) a pad ( 12 ) is applied and that encapsulation element ( 1 ) with the desiccant ( 5 ) document ( 12 ) is applied. Method according to claim 15, characterized in that the encapsulation element ( 1 ) from the top to the with the desiccant ( 5 ) document ( 12 ) and in a heated, flowable state with surface areas of the substrate which are not mixed with the desiccant ( 5 ) are brought into contact. Method according to one of claims 5 to 16, characterized in that the drying agent ( 5 ) to be covered ( 12 ) a plunger ( 16 ), with which the desiccant ( 5 ) on the encapsulation element ( 1 ) is printed. Method according to one of claims 5 to 17, characterized in that the with the desiccant ( 5 ) to be covered ( 12 ) a mold ( 17 ), with which the desiccant ( 5 ) into the heated encapsulation element ( 1 ) is pressed into it. Method according to one of claims 5 to 18, characterized in that the pad ( 12 ) a plane bearing surface ( 13 ), to which the desiccant ( 5 ) is applied. Method according to one of claims 5 to 18, characterized in that the pad ( 12 ) a structured bearing surface ( 13 ), the projections ( 18 ), which with the desiccant ( 5 ). Method according to one of claims 1 to 20, characterized in that the encapsulation element ( 1 ) consists of a glass, in particular of a float glass. A method according to claim 21, characterized in that the encapsulation element ( 1 ) is heated to above a softening temperature or above a melting temperature by the action of heat (W). Method according to one of claims 1 to 22, characterized in that the encapsulation element ( 1 ) consists of a glass, a metal or a ceramic and that the encapsulation element is heated to a temperature (T) which is between 200 ° C and 2000 ° C. Method according to one of claims 1 to 23, characterized in that the drying agent ( 5 ) is activated by the action of heat (W). Method according to one of claims 1 to 24, characterized in that the drying agent ( 5 ) is sintered by the heat (W). Method according to one of claims 1 to 25, characterized in that the drying agent ( 5 ) on an initially unstructured surface ( 1a ) of the encapsulation element ( 1 ) is applied. Method according to one of claims 1 to 26, characterized in that as drying agent ( 5 ) a chemisorbent or physisorbent material is used. Method according to one of claims 1 to 27, characterized in that the drying agent ( 5 ) on a plurality of surface areas ( 11 ) of the surface ( 1a ) of the encapsulation element ( 1 ) applied on the surface ( 1a ) the encapsulation element ( 1 ) form a matrix-shaped arrangement (M). Method according to one of claims 1 to 28, characterized in that a protective encapsulation ( 10 ) for an electro-optical or opto-electronic component ( 20 ), in particular for a light-emitting diode, in particular an organic light-emitting diode, or a display or a surface illumination source is produced. Protective encapsulation ( 10 ) for at least one electronic component ( 20 ), with a planar encapsulation element ( 1 ), which on at least one side has a structured surface ( 2 ) with at least one cavity ( 8th ), and a drying agent ( 5 ), which in the at least one cavity ( 8th ) is arranged. Protective encapsulation according to claim 30 by a method according to any one of claims 1 to 29. Protective encapsulation according to claim 30 or 31, characterized in that the encapsulation element ( 1 ) of the protective encapsulation ( 10 ) has a maximum layer thickness (D) of less than 0.5 mm, preferably between 0.2 to 0.5 mm. Protective encapsulation according to one of Claims 30 to 32, characterized in that the desiccant ( 5 ) to the ground ( 7 ) and to the side wall ( 9 ) of the at least one cavity ( 8th ) is festgebacken. Protective encapsulation according to one of Claims 30 to 33, characterized in that the side of the planar encapsulation element ( 1 ), on which the at least one cavity ( 8th ) and the drying agent ( 5 ), an exposed surface of the protective encapsulation ( 10 ). Electronic component ( 20 ), comprising: - a carrier substrate ( 3 ), - at least one electronic component ( 4 ) mounted on the carrier substrate ( 3 ), and - a protective encapsulation ( 10 ) with a planar encapsulation element ( 1 ) and a drying agent ( 5 ), wherein the encapsulation element at least one cavity ( 8th ), which the at least one electronic component ( 4 ), and wherein the drying agent ( 5 ) in the at least one cavity ( 8th ) is arranged.