DE102007033296A1 - Heat and vibration critical component e.g. transformer, connecting method, involves inserting component into container, casting component by grouting mass, and thermally connecting container with device housing - Google Patents

Abstract

The method involves inserting a safety critical electrical component (2) into a plastic container (5) and casting the safety critical electrical component by a plastic grouting mass (3). The plastic container is mechanically and thermally connected or screwed with a housing of a device (1), where wall thickness of the container ensures necessary electrical isolation of the safety critical electrical component. A heat conductive paste (6) is provided between the container and the housing.

Description

The The invention relates to a method for isolated mechanical and thermal connection of a safety-critical electrical component the housing a device.

at electrical components whose operating voltage is above the permissible low voltage which are therefore critical to safety, mandatory air and creepage distances to touch Parts are adhered to.

Farther are vibration-loaded components, such as transformers or capacitors on motors, secure mechanically secure. Also is the heat loss dissipate from components to the environment.

These Requirements to the fact that often components are shed in a housing. there the potting compound serves as a mechanical fixation and as a heat conductor to transport the heat loss to the housing. As a simple casting method no bubble-free potting compound generated, must the safety-relevant clearances and creepage distances continue to be complied with become. this leads to to a correspondingly large Construction volume of the housing. The non-bubble-free potting compound can not be used as insulating material to be viewed as.

One Bubble-free casting, however, requires a high production engineering Effort. For example, a system for vacuum casting with a high Investment connected.

alternative be for vibration-loaded components also other mechanical fasteners used and the heat loss is dissipated via fans. This leads to even larger volume of construction casing and increased the vulnerability of the device.

It It is an object of the invention to provide a method for mechanical and thermal Connection of a safety-critical component to a housing of a equipment specify, in which the disadvantages mentioned are avoided.

These Task is solved by that the component is inserted into a plastic container, therein by a potting compound is potted and the plastic container mechanically and thermally with the housing of the device is connected.

embodiments The invention are specified in the subclaims.

The Introducing the device in the plastic container and the subsequent one Allow casting both compliance with insulation requirements and the mechanical and thermal connection of the device to the Casing. The plastic container allows due to its high insulation resistance the use of short distances. The Potting compound secures the mechanical thermal connection. A Vibration or shock load is no longer transferred to the Component. Thus the problem of isolation from the problem is the mechanical connection disconnected. Due to the improved isolation can smaller distances chosen and so a compact design can be realized. For the casting can production technology favorable Dimensions of the container chosen become.

there can the wall thickness of the plastic container chosen so low be as the insulation requirements allow.

At the Shed of the component in the container becomes a simple and inexpensive Process used in which it does not depend on the absence of bubbles. To have to only the mechanical and thermal requirements of the casting be fulfilled.

The Procedure can also be done this way be that the device overmoulded with a plastic compound while the plastic container is formed at the same time. Then is waived a separate casting. The resulting plastic body serves as a heat sink and as mechanical fixation. In this case, the plastic as an insulating material be considered.

Of the resulting plastic container gets easy on the case of the device attached. Because the case mostly used as a heat sink, gets over it the heat loss dissipated.

Around the heat transfer To improve, is between the plastic container and the housing thermal grease brought in.

The Invention will be described below in embodiments with reference to FIG associated Drawings closer explained. Show it:

1 the prior art with a molded component and

2 a component cast in a plastic container.

In 1 is a state of the art device 1 with a component therein 2 shown. This component 2 is on the circuit board 4 fixed and in the casting compound 3 embedded. The air requirements resulting from safety requirements and creepage distances s must be respected because the potting compound 3 not to be considered as insulating material.

In 2 is the component 2 also on the circuit board 4 attached. It is in the container 5 with the potting compound 3 shed. The container 5 is about the screws 7 on the device 1 attached. The thermal compound 6 provides a good heat transfer between the container 5 and the wall of the device 1 ago.

This construction ensures secure mechanical fastening and good heat transfer. The requirement for insulation is beyond the wall thickness of the container 5 ensured.

The container 5 can with the potting compound 3 also be injected in one process.

Claims (6)

Method for the isolated mechanical and thermal connection of a safety-critical electrical component to the housing of a device, characterized in that the component ( 2 ) in a plastic container ( 5 ) is inserted therein by a potting compound ( 3 ) and the plastic container ( 5 ) is mechanically and thermally connected to the housing of the device. A method according to claim 1, characterized in that by the wall thickness of the plastic container ( 5 ) the necessary electrical insulation of the component ( 2 ) is ensured. Method according to claim 1, characterized in that that to the shedding a simple potting process is used that does not require blistering is respected. A method according to claim 1, characterized in that the casting compound ( 3 ) Plastic is, with which the component ( 2 ) and thus the container ( 5 ). Method according to claim 1, characterized in that the container ( 5 ) with the housing ( 1 ) is screwed. Method according to claim 5, characterized in that between the containers ( 5 ) and the housing ( 1 ) Thermal grease ( 6 ) is introduced.