DE102007035020A1 - Contact device for use in chip test arrangement, for contacting electrical contact, has opening through which electrically conductive liquid produces contact for electrical contact - Google Patents

Abstract

The device (18) has a contacting equipment (1) comprising a chamber (2) for receiving an electrically conductive liquid. The chamber has an opening (4) through which the electrically conductive liquid produces a contact for an electrical contact. An actuating device (5) is provided in the chamber. The electrically conductive liquid presses out from the opening with the actuating device to form a liquid drop on the opening. A tube is connected to the opening. An independent claim is also included for a method for forming a contact connection to an electrical contact.

Description

The The present invention relates to a contact device for contacting at least one electrical contact, a test arrangement and a Method.

Such a contact device for contacting electronic circuits is known from EP 0262371 and comprises a contacting device having a needle. The contact device is therefore also referred to as a probe card. The probe card is attached to a holder of a wafer prober that is used to perform a functional test prior to singulation of the wafer on which the electronic circuits are formed as chips and before packaging the chips. Usually, the contact device comprises a plurality of similar contacting means for establishing an electrical connection to a respective test pad, as the functional connections provided on the chips are called.

• i.) Durch die Nadeln können die Testpads beschädigt, was zu Problemen beim Anbanden von Drähten und folglich Ausbeuteverlusten führen kann.
• ii.) Die Spitzen der Nadel müssen alle ziemlich genau auf der gleichen Höhe enden, so daß die Testpads alle gleichzeitig kontaktiert werden. Die erforderlichen Toleranzen lassen sich jedoch während der Fertigung schwer erreichen und nach vielen Funktionsprüfungen aufgrund der Biegbarkeit der Nadeln noch schwerer beibehalten.
• iii.) Die elektronischen Schaltungen werden bevorzugt kurz nach der Herstellung der Chips getestet, wenn der Wafer noch eine Temperatur von weit über 100°C haben kann. Diese hohe Temperatur kann über die Nadeln auf die Nadelkarte übertragen, wodurch diese sich verformen kann. Diese Verformung kann aufgrund der Länge der Nadeln zu einer verstärkten Fehlausrichtung der Spitzen der Nadeln führen.

With known needle cards, the following problems may arise:

• i.) The needles can damage the test pads, which can lead to problems in bonding wires and consequently yield losses.
• ii.) The tips of the needle must all end up pretty much at the same height, so that the test pads are all contacted simultaneously. However, the required tolerances can be difficult to achieve during production and even more difficult to maintain after many functional tests due to the flexibility of the needles.
• iii.) The electronic circuits are preferably tested shortly after the manufacture of the chips, if the wafer can still have a temperature of well over 100 ° C. This high temperature can be transferred to the needle card via the needles, which can cause it to deform. This deformation can lead to increased misalignment of the tips of the needles due to the length of the needles.

Disclosure of the invention

Of the present invention is based on the object, a contact device to provide for contacting electrical contacts, which has improved performance properties.

The The object underlying the invention is achieved by a contact device for contacting electrical contacts with the features of Patent claim 1, a test arrangement according to claim 14, a contact device according to claim 15 and a method according to claim 19.

The The present invention relates to a contact device for contacting of electrical contacts, wherein the contact device is a chamber for receiving an electrically conductive liquid and the chamber has an opening over the the liquid in contact with an electrical contact can occur.

advantageously, test pads of a chip can be contacted by that the electrically conductive liquid by means of an actuator through the opening is pushed out of the chamber. It comes to none Damage to the contact. The openings of the Chambers can also be easily arranged in a plane, so that the contacts, for example, test pads all at the same time be contacted. A deformation of the contact device for contacting of electronic circuits does not lead to increased misalignment the openings of the contact device. Furthermore The chambers can be arranged very close to each other, so that accordingly the test pads can have a relatively small distance. Because the position of the liquid droplets pushed out of the chamber can be determined exactly, the test pads can be very small be formed and it is therefore on the surface of the wafer no space wasted. In addition, exercises from the openings pressed liquid only a negligible Force out the wafer.

In An embodiment comprises the actuating device a piezo element. With the piezoelectric element can electrical energy easily converted into mechanical work.

In Another embodiment is the opening formed such that the electrically conductive Liquid due to surface tension in the chamber can be restrained.

In Another embodiment is a flexible film or membrane is provided which covers an opening of the chamber and as a contact surface for contacting the electrical Contact serves. In a further embodiment can a tube may be provided which connects to the chamber is and at the free end of a drop of liquid to Contact is formed.

The Liquid does not cause abrasion and therefore contaminates not by this, so that the electrical contact not deteriorated.

In yet another embodiment, the actuating device has a membrane, with which the volume of the chamber for squeezing and / or sucking in the Flüssigkeitsstrop fens is changed.

advantageously, no liquid is lost, so that no Device must be provided to recreate the chambers fill.

Brief description of the drawings

in the The following is the invention with reference to the drawings described in more detail. Show it:

1 a schematic view of a contact device for contacting electronic circuits; and

2 a schematic view of the contact device for contacting electronic circuits 1 who contacts a chip,

3 shows a further embodiment of the contact device for contacting,

4 shows a rotatable mounting of a tube, and

5 shows a further embodiment of an actuating device.

1 shows a schematic view of a contact device 18 for contacting electrical contacts, in particular electronic circuits. The contact device 18 is on a bracket 13 a Waferprobers attached and includes on its underside a plurality of contacting devices 1 , The contacting devices 1 are generally isolated from each other and each have a chamber 2 on, which is filled with an electrically conductive liquid. In this context, the term "liquid" is also intended to include suspensions The chambers may also be tube-like formed from the underside of the contact device 18 protrude. Each of the chambers 2 is up through a membrane 3 closed and has an opening at the bottom 4 on. The liquid gets in the chambers 2 retained despite the openings due to their surface tension. The openings 4 can also each be closed by a further elastic membrane which is electrically conductive. Instead of the other membrane can also be a flexible film 35 be provided, which is electrically conductive and can be arched outward at a corresponding pressurization. The outwardly arched foil 35 or membrane is a contact surface, which is used for electrical contacting of an electrical Kontak TES. In 1 only shows the chamber 2 located on the far left, a flexible conductive foil 35 on. Depending on the embodiment may also be several or all openings 4 with a membrane or foil 35 be covered.

On the sides of the membranes 3 , which from the chambers 2 are facing away from each other, an actuating device is provided, which, for example, in the form of a piezoelectric element 5 is shown. The piezo element changes the deflection of the membrane 3 depending on the control. Depending on the deflection of the membrane 3 becomes the volume of the chamber 2 changed. To the effect of the piezo elements 5 To reinforce, the openings can 4 have a substantially smaller cross-sectional area than the surface of the membrane 3 , The piezo elements 5 are via electrical lines 6 and 7 with a controller 8th connected. In this case, two or more piezo elements 5 over the same lines 6 . 7 with the controller 8th be connected when these piezo elements 5 should be controlled together. On top of the controller 8th are control connections 12 intended. On a wall of each chamber 4 is a liquid contact 9 intended. Every fluid contact 9 is via an electrical line 10 with a test connection 11 connected and contacted the liquid in the corresponding chamber 2 , To form the contact 9 For example, the wall of the chamber may be coated in a region with a metal layer. Several contacts 9 can with the same test connection 11 be connected when these contacts 9 for example, to contact devices 1 belong, with the help of a certain voltage to be applied to multiple test pads.

2 shows a schematic view of the contact device 18 for contacting electrical contacts of an electronic circuit 17 out 1 that a chip 14 electrically contacted. To a chip 14 electrically contact, the contact device 18 with the help of the holder 13 to the next in a suitable position directly over the chip 14 with the electronic circuits 17 emotional. Then be from a Waferprober on the control terminals 12 Control signals to the controller 8th Posted. The control 8th then sets according to the control signals a voltage to certain lines 6 . 7 at. The applied voltages cause an actuation of the actuator, in the example chosen a longitudinal extension of certain piezo elements 5 , respectively, against the corresponding membrane 3 Press and thereby the liquid 15 from the openings 4 of the chambers 2 to press. In this case, at least liquid drops 27 formed, directly or through a foil 35 or another membrane electrical contacts, such as test pads 16 to contact. This will create an electrical connection between specified test pads 16 and test connections 11 produced. It will now be from a test system to the test ports 11 applied appropriate currents or voltages, or the currents or voltages at the test terminals 11 measured. If the voltages do not continue to the particular piezoe ELEMENTS 5 be put on, these pull together again, so that the membrane 3 is moved back to the initial state and the volume of the chamber 2 is reduced. At the same time, the liquid drop becomes 27 sucked back into the chamber. Due to its surface potential, the liquid dissolves 15 completely from the test pads 16 and, for example, is completely returned to the chambers 2 withdrawn. Also when using slides 35 These are moved back to the starting position. Thus, the electrical connection between the test pad 16 and the contacting device 1 interrupted again. The contact device 18 can also be reversed with the openings 4 Be set up at the top to complete withdrawal of the liquid 15 or the foil 35 to promote.

For example, by evaporation lost liquid 15 To complement, each of the chambers can 2 be connected to a refill, in the contact device 18 is integrated.

Depending on the chosen embodiment, spacers may be used 20 on the underside of the contact device 18 be provided for contacting circuits to a predetermined distance between the bottom of the contact device 18 and the top of the chip 14 manufacture.

3 shows a further embodiment of the contact device 18 for contacting electrical circuits, wherein the contact device 18 tube 21 that is in the openings 4 are arranged. The tubes 21 serve as an extension to the openings 4 and allow a chip 14 to contact, at a fixed distance to the bottom of the contact device 18 is arranged. Depending on the application, free ends of the tubes 21 also with a foil 35 or membrane, as in the first left tube 21 is shown.

In another embodiment, the tubes are 21 in the longitudinal direction of the chamber 2 movable in the chamber 2 stored. For example, a biasing spring 22 in the chamber 2 be arranged, which is the tube 21 in a fixed insertion depth in the chamber 2 holds. The biasing spring 22 is designed in such a way that a deeper insertion of the tube 21 in the chamber 2 is possible. In this way, different distances between the contact device 18 and contact surfaces, such. B. Test pads 16 a chip to be contacted 14 be compensated. For this purpose, the contact device 18 so close to the chip 14 moved on until the tubes 21 electrically contact the associated contact surfaces. The tubes can 21 different insertion depths in the chamber 2 exhibit. The chamber 2 can be an investment element 23 against which the biasing spring 22 is supported.

Depending on a further embodiment, the tubes are 21 not only along a longitudinal direction of the chamber 2 but also at different angles of inclination pivoting in the chamber 2 stored. To provide this possibility of movement, for example, a ball bearing 24 intended.

4 shows a section of a further embodiment of the contact device 18 with a chamber 2 , wherein in the lower end of the chamber 2 a spherical ring-shaped recess 25 is provided. In the recess 25 is a sphere element 26 stored, which has the shape of a sphere. The ball element 26 and the recess 25 put the ball bearing 24 dar. The ball element 26 is sealing in the recess 25 movably mounted. By the ball element 26 is a tube 21 sealingly guided. The tube 21 is with a biasing spring 22 connected in the chamber 2 is arranged and with a contact element 23 is attached. This is the tube 21 both pivotable and displaceable on the contact device 18 supported. The ball element 26 is for example made of an elastic material such. B. plastic and thus enables a seal of the chamber 2 ,

In this way it is possible to adjust the orientation of the tube 21 to change, so the tube 21 can be aligned with a contact pad. Furthermore, it is possible to use the tube 21 deeper or less deep into the chamber 2 insert and thus a distance between the bottom of the contact device 18 and a free end of the tube 21 set. For an electrical contact with the aid of the actuating device, for example by means of the piezoelectric element 5 and the membrane 3 the electrically conductive liquid of the chamber 2 through the tube 21 pushed out downward, so that a drop of liquid 27 at the free end of the tube 21 trains as in 4 is shown. With the help of the liquid drop 27 can a contact pad, such. B. a test pad 16 electrically conductive, either directly or via a conductive foil 35 or a membrane.

The tubes 21 represent hollow needles, which may be formed, for example, the shape of injection needles. The needles can be individually adjustable depending on a selected embodiment and thus used universally for various chip products. To open the contact connection, the conductive liquid is returned to the tube 21 sucked. The process of pushing out and sucking in, for example, by means of the piezoelectric element and the membrane 3 or with any other kind of Be actuating element, such as. B. an electromagnet and the membrane are executed.

In a further embodiment, a suction device 28 at the contact device 18 provided for interrupting the electrical connection between the contacting device 1 and the electrical contact, the liquid drop 27 sucks. The suction device 28 is in the contact device 18 integrated and has a suction channel 29 up, to the free end of the tube 21 is guided.

Also in the embodiment of the 1 can be a suction device 28 be provided, which has corresponding suction channels 29 adjacent to the opening 4 is guided. This can be a single suction device 28 a variety of suction channels 29 for the multitude of chambers 2 be provided. The suction channels 29 can do this in an end region of the chamber 2 near the opening 4 open or directly adjacent to the opening 4 another opening 30 exhibit. The further opening 30 is arranged in such a way that a at the opening 4 forming liquid drop 27 , as in 2 is shown, also at least partially the further opening 30 wetted. The suction device 28 is used to remove the liquid drop 27 controlled accordingly. For suction, the suction device 28 a corresponding suction motor. In this way it is possible the electrical contact between the electrical line 10 and a contact pad to be contacted, such. B. the test pad 16 by sucking off the liquid drop 27 to interrupt.

5 shows a further embodiment, wherein as actuating means a pump 31 in the contact device 18 is provided, which has a channel 34 with the chamber 2 connected is. The pump 31 in turn, there is a suction line 32 with a reservoir 33 in connection. In the reservoir 33 is electrically conductive liquid 15 present with the pump 31 in the chamber 2 can be pumped. Depending on the chosen embodiment, the pump is 31 designed as a simple pump that can only promote in one direction. In this embodiment, the electrically conductive liquid from the reservoir 33 over the suction line 32 and the pump 31 in the chamber 2 pumped to a drop of liquid 27 train. After the measuring process, the liquid drop can 27 for example, by a suction device 28 , as in 5 is shown sucked off. The suction device 28 can also be outside the contact device 18 be arranged.

In a further embodiment, the pump 31 Pump in two directions and it can be on the suction device 28 be waived. In this embodiment, the electrically conductive liquid 15 from the reservoir 33 in the chamber 2 pumped to the liquid drop 27 for electrically contacting a contact form. If the electrical contact is interrupted, then the pump 31 the electrically conductive liquid over the channel 34 at least partially out of the chamber 2 pumped out and into the reservoir 33 promoted. In this way, the liquid of the liquid drop 27 at least partly back to the chamber 2 sucked.

The actuator can by means of various physical functions the formation of a liquid drop 27 at the opening 4 or at the free end of a tube 21 form. Depending on the embodiment of the actuator may also remove the liquid drop 27 be achieved by the actuator. For example, with the aid of a change in volume across a membrane, fluid can escape from the chamber 2 be pushed out to the liquid drop 27 train. To suck back the liquid, the membrane can be re-deformed to the volume of the chamber 2 increase again to the liquid drop 27 at least partially back in the chamber 2 suck back. Furthermore, the actuating device by means of a pressure increase, for example in the form of a pump 31 work to get the electrically conductive liquid out of the opening 4 or from the free end of the tube 21 in the form of a liquid drop 27 push out. Also the pump 31 may be formed in such a way that by sucking or by a pressure reduction in the chamber 2 the liquid drop 27 back in the chamber 2 is sucked back. The various embodiments of the actuating device can also be combined with a suction device, which is used to aspirate the liquid drop 27 is used.

The contacting device 18 may be part of a test arrangement with which electronic circuits, in particular memory components, are checked for a correct electrical function.

1

contacting

2

chamber

3

membrane

4

opening

5

piezo element

6

electrical management

7

electrical management

8th

control

9

liquid contact

10

electrical management

11

test port

12

control terminal

13

bracket

14

chip

15

liquid

16

Test area

17

electronic circuit

18

contraption for contacting electronic circuits

20

spacer

21

tube

22

biasing spring

23

contact element

24

ball-bearing

25

recess

26

ball element

27

liquid drops

28

suction

29

suction

30

further opening

31

pump

32

suction

33

reservoir

34

channel

35

Further membrane

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• EP 0262371 [0002]

Claims (20)

Contact device ( 18 ) for contacting electrical contacts ( 16 ) with a contacting device ( 1 ), characterized in that the contacting device ( 1 ) a chamber ( 2 ) for receiving an electrically conductive liquid ( 15 ), and that the chamber ( 2 ) an opening ( 4 ), via which the electrically conductive liquid makes contact with the electrical contact ( 16 ) can produce. Contact device according to claim 1, characterized in that an actuating device ( 5 . 31 ) which is operatively connected to the chamber ( 2 ) that with the actuator ( 5 . 33 ) the electrically conductive liquid ( 5 ) from the opening ( 4 ) can be pushed out so that at least one drop of liquid ( 27 ) at the opening ( 4 ). Contact device according to claim 2, characterized in that the actuating device is a piezoelectric element ( 5 ). Contact device according to one of claims 1 to 3, characterized in that the opening ( 4 ) is designed such that the electrically conductive liquid ( 15 ) due to their surface tension in the chamber ( 2 ) can be retained when a drop of liquid ( 27 ) trains. Contact device according to one of the preceding claims, characterized in that a membrane ( 3 ) to the chamber ( 2 ), which communicates with the actuator, whereby by means of the membrane ( 3 ) the volume of the chamber ( 2 ) is variable and the liquid from the chamber ( 2 ) through the opening ( 4 ) can be moved out and / or through the opening ( 4 ) at least partially back into the chamber ( 2 ) can be sucked. Contact device according to one of claims 1 to 5, characterized in that a tube ( 21 ) with the opening ( 4 ), via which the liquid ( 15 ) to a free end of the tube ( 21 ), so that at the free end of the tube ( 21 ) a drop of liquid ( 27 ) can be formed. Contact device according to claim 6, characterized in that the tube ( 21 ) slidably on the contact device ( 18 ) is held. Contact device according to one of claims 6 or 7, characterized in that the tube ( 21 ) pivotable on the contact device ( 18 ) is held. Contact device according to one of claims 1 to 8, characterized in that a suction device ( 28 . 29 ) provided with a suction channel ( 29 ) adjacent to the opening ( 4 ) and / or the free end of the tube ( 21 ) is guided. Contact device according to one of claims 1 to 9, characterized in that the tube ( 21 ) via a biasing spring ( 22 ) resiliently on the contact device ( 18 ) is held. Contact device according to one of claims 1 to 10, characterized in that the tube ( 21 ) via a ball bearing ( 24 ) is pivotally mounted. Contact device according to one of claims 2 to 11, characterized in that the actuating device as a pump ( 31 ) is formed, the electrically conductive liquid keit in the chamber ( 2 ) pumps to a drop of liquid ( 27 ) train. Contact device according to one of claims 1 to 12, characterized in that the opening ( 4 ) or the free end of the tube ( 21 ) with a flexible film ( 35 ) or membrane is sealed, that the film or membrane is electrically conductive and as a contact surface for touching the electrical contact ( 16 ) serves. Test arrangement with a contact device according to one of claims 1 to 13. Contact device with means for electrical Contacting a contact, wherein the means is an electrically conductive Have liquid. Contact device according to claim 15, wherein the electric conductive liquid in direct contact with the electrical Contact is bringable. Contact device according to claim 15, wherein the electrically conductive liquid is an electrically conductive membrane or an electrically conductive film ( 35 ) to connect to an electrical contact. Contact device according to one of the claims 15 to 17, with actuating means for moving the electric conductive liquid for forming a connection between the electrically conductive liquid and the electrical Contact. A method for forming a contact connection to an electrical contact, wherein electrically conductive liquid is kept in a chamber, wherein the chamber ( 2 ) an opening ( 4 ), wherein the liquid from the opening ( 4 ) is moved out to make the electrical contact touch. The method of claim 19, wherein the opening ( 4 ) with a flexible film ( 35 ) is closed, wherein the film is electrically conductive, wherein the film is curved using the liquid to the outside and is brought into contact with the electrical contact.