WO2016146613A1

WO2016146613A1 - Electronic control device

Info

Publication number: WO2016146613A1
Application number: PCT/EP2016/055511
Authority: WO
Inventors: Ilya Kuperberg; Heiko Buss
Original assignee: Robert Bosch Gmbh
Priority date: 2015-03-18
Filing date: 2016-03-15
Publication date: 2016-09-22
Also published as: DE102015204905A1

Abstract

Disclosed is an electronic control device (100) comprising: a housing (10); a circuit carrier (20) having a power electronics component (30) that is arranged thereon; the circuit carrier (20) and the power electronics component (30) are in contact with the housing (10) via a heat conducting medium (40); heat generated by the power electronics component (30) can be dissipated from the circuit carrier (20) in a specific direction; and the circuit carrier (20) is secured in the housing (10) by means of the heat conducting medium (40).

Description

Description title

Electronic Control Device The invention relates to an electronic control device. The invention further relates to a method for producing an electronic control device.

PRIOR ART In the thermal connection of so-called slug-up SMD power components, on the one hand a distance between the component and a heat sink is determined by installation tolerances of the circuit carrier, by component tolerances and housing tolerances. Disadvantage must be taken into account in this way a variety of tolerances that require a relatively large sized Wärmeleitmedium, resulting in a derivative of thermal

Can reduce energy.

DE 10 2012 218 932 A1 discloses an electronic component for the cooling of slug-up components.

DE 10 2010 001 958 A1 discloses an electronic control unit with power components, wherein the power components each have a heat-slug element which is provided to receive heat of the respective power device. The heat-slug elements are in thermal contact with a foil-formed heat-conducting element, thereby forming a larger area with a correspondingly larger heat capacity. Disclosure of the invention

An object of the invention is to provide an improved electronic control device with an electronic power device.

The object is achieved according to a first aspect with an electronic control device, comprising:

a housing;

a circuit carrier having an electronic power device disposed thereon;

wherein the circuit carrier and the electronic power device are contacted by means of a Wärmeleitmediums with the housing; wherein heat of the power device is away from the circuit carrier wegführbar; and

- Wherein the circuit carrier is fixed in the housing by means of the heat transfer medium.

According to a second aspect, the object is achieved with a method for producing an electronic control device, comprising the steps:

- Force-free fixing of a circuit carrier with an electronic

Power component relative to a housing;

At least partially disposing a pasty heat transfer medium on a side of the circuit substrate on which the electronic power device is disposed;

- Closing the housing; and

Curing the Wärmeleitmediums.

In this way, the circuit substrate can be fixed force-free in the housing, wherein the heat-conducting medium can take over a mechanical fixation of the circuit substrate relative to the housing in the cured state. Due to the fact that the heat-conducting medium can be introduced very thinly, an optimized heat dissipation from the electronic power component to the housing is also supported. The

Power component is connected in this way with only one measure of a tolerance chain to the functioning as a heat sink housing. The heat conduction Medium can take over the thermal advantageous also the mechanical fixation of the circuit substrate within the housing.

Preferred embodiments of the electronic control device and method are the subject of dependent claims.

An advantageous development of the control device is characterized in that the circuit carrier is positioned with the electronic power component relative to the housing by means of at least three support areas, wherein at least one support area between the housing and the electronic

Power component is formed. In this way, a three-point support is realized between the housing and the circuit carrier, whereby a stable fixation of the circuit carrier supported in the housing and a mobility of the fixed circuit substrate is advantageously reduced.

A further advantageous development of the control device is characterized in that at least one of the three support areas as a

Housing rib of the housing is formed. As a result, an already existing structure of the housing can be used for the stable positioning of the circuit carrier within the housing.

A further advantageous development of the control device is characterized in that the circuit carrier with the electronic

Power component is positioned relative to the housing by means of three support areas, wherein a support area between the housing and the electronic power device is formed, and wherein two bearing areas are formed as housing ribs of the housing. This provides a stable fixation of the circuit carrier to the power device within the housing. A simple and precise arrangement of the

Circuit carrier in the housing with a good grip of the circuit carrier within the housing is supported in this way.

An advantageous development of the control device is characterized in that by means of at least one spacer a defined distance between a surface of the electronic power device and the housing is made. Thereby, a defined distance can be created, which is provided as a later contact area between the power device and the housing, wherein in this contact region, the thermally bonding heat transfer medium is inserted.

Further advantageous developments of the control device are characterized in that the at least one spacer is formed on the power component or designed as a housing rib of the housing. As a result, different variants of spacers are provided, which allow the circuit carrier by means of the fixing element without force on

Fix the housing. In the case of the spacer on the power component, a pasty heat transfer medium can be inserted between the power component and the housing, resulting in a fixation of the power component to the housing and a heat transfer from

Power component to the housing improved.

A further advantageous development of the control device is characterized in that by means of fixing elements the circuit carrier is fixed in a force-free manner to the housing during hardening of the originally pasty heat-conducting medium. In this way, an unintentional shifting of the circuit carrier relative to the housing can be avoided in a production phase in which the paste-like heat-conducting medium is already inserted. The smallest possible closing size between the circuit carrier and the housing is advantageously supported in this way.

A further advantageous development of the control device is characterized in that the fixing elements comprise at least one of the following group: plastic sleeve, dowel, contact spring, snap element. This makes it possible that no screw must be used as a fixing element, which would exert a disadvantageous mechanical force on solder joints of the circuit substrate. In this way, the circuit carrier can be fixed relative to the housing without bias, so that the pasty heat conducting medium can cure until it takes over a mechanical attachment of the circuit substrate within the housing in the cured state. The invention will be described below with further features and advantages with reference to several figures in detail. In this case, all features, regardless of their representation in the description and in the figures, as well as regardless of their dependency in the claims, the subject of the present invention. The figures are primarily intended to illustrate the principles essential to the invention and are not necessarily drawn to scale. Same or functionally identical elements have the same reference numerals.

In the figures shows:

Fig. 1 a is a cross-sectional view through a conventional electronic

Control device before assembly;

Fig. 1 b is a cross-sectional view through a conventional electronic

Control device after assembly;

Fig. 2 is a cross-sectional view through an embodiment of

electronic control device;

3 is a perspective view of an electronic power device;

4 to 10 examples of fixing elements;

Fig. 1 1 is a perspective view of an electronic control device; and

12 shows a basic sequence of an embodiment of the method according to the invention.

Description of embodiments

In the text which follows, an electronic power component is understood to mean a "slug-up component" which generates heat generated during operation of the power component by means of a heat sink from a printed circuit board on which the Slug-up component is mounted, directed away. The heat sink may be formed as a tinned metal plate (eg made of copper), which is encapsulated in the production of the power device with molding compound. The heat sink is thermally contacted directly with a heat sink without penetrating the circuit board. This is achieved by connecting the slug-up component and the heat sink to opposite sides

Surfaces of the power device are arranged.

Fig. 1a shows a cross-sectional view through a conventional electronic control device 100 prior to assembly. A circuit carrier 20, preferably a printed circuit board, on which an electronic power component 30 in SMD design is arranged can be seen. By means of a heat conducting medium 40, thermal energy of the power component 30 can be delivered to the housing 10 during operation. The housing 10 thus also functions as a heat sink.

FIG. 1 b shows a cross-sectional view through the assembled electronic control device 100 of FIG. 1 a. It is indicated that by a

Tolerance chain of many tolerances, which are indicated by arrows, even with a statistical tolerance calculation results in a large closing X, which leads to a limited dissipation of thermal power loss of

Can lead component 30 because the paste-like heat transfer medium 40 must be inserted in a large thickness. The tolerance chain can be replaced by a

Movement of the cooling surface, a height of the heat sink, a warping of the circuit substrate 20, etc. are justified. By a dashed line is a

Curvature of the circuit substrate 20 indicated with the power component 30 disposed thereon. As a consequence, the closing dimension X must be dimensioned disadvantageously relatively large, for example, about 0.4 mm to about 0.6 mm high.

Another, not shown in figures known way to dissipate thermal energy of the power device is to realize the thermal connection of the power device to the housing via insulated films. In this way, an improvement of the thermal

Resistance can be achieved, but with additional spring elements are required to produce a required contact force of the film to the power device. The high forces caused thereby can adversely effect that solder joint reliability may be compromised. Namely, the additional mechanical forces on solder pins of the device can shorten an operation time of the device on the substrate from a viewpoint of thermal cycling processes.

Fig. 2 shows a cross section through an embodiment of the electronic control device 100 according to the invention. It can be seen that a

Circuit carrier 20 at an upper side and at a lower side with a

Wärmeleitmedium 40 to the housing 10 mechanically and thermally

is connected. In addition, the power component 30 is also mechanically and thermally connected to the housing 10 by means of the thermal interface medium 40 (TIM). On the underside of the power component 30, spacers 31 or spacing knobs, which define a defined distance of a surface of the power component 30 from the surface, can be seen

Provide housing 10. There should be at least one spacer 31 on the

Power device 30 may be provided to allow immobile contacting of the power device 30 to the housing 10 and an electrical short circuit between the power device 30 and the

To avoid housing 10.

As a result, a defined, minimal thermal gap is provided between a surface of the power component 30 and the housing 10, for example with a height of approximately 0.1 mm to approximately 0.3 mm, as a result of which a defined

Cavity is formed, in which the pasty heat transfer medium 40 can be inserted. In this way, the heat-conducting medium 40 after curing takes on the function of a mechanical and effective thermal connection of the circuit substrate 20 with the power component 30 to the housing 10th

As a result, a three-point support is thereby realized between the housing 10 and the circuit carrier 20, wherein housing fins 11 are provided on the housing 10 by means of which the circuit carrier 20 can be arranged in a defined position in the housing 10. A third point of the Three-point support is formed by the power device 30 itself, which has at least one, preferably three or more spacers 31, which contact with the spacers 31 to the housing 10. The housing rib 1 1 acts as a spacer for setting a defined distance between the power device 30 and the housing

10th

Variants of the control device 100 that are not illustrated in FIGS. Provide that the three-point support between the housing 10 and the circuit carrier 20 can be realized by three power components 30 or by a power component 30 and two housing ribs 11 or by two power components 30 and a housing rib 11.

3 shows a perspective view of the power device 30 in the form of an electronic MCPP B6 bridge circuit (Multi Chip Power

Package), which e.g. to control an electronically commutated electric motor is used. By means of the spacers 31, a usable cavity between the power component 30 and the housing 10 can be provided. The distance between the power device 30 and the housing 10 may also be achieved via other elements not shown in figures, such as printed on the circuit carrier 20

Layers / strips.

The thermal connection of the power component 30 and the heat sink is preferably carried out by means of a heat transfer medium 40 in the form of a

Thermal paste (e.g., in the form of a 2K paste), which also at other locations of the circuit substrate 20 further components, such. Capacitors, coils, shunts, tracks (not shown) thermally connected to the heat sink or the housing 10. This thermal connection takes over in the cured state, the mechanical attachment of the assembled circuit substrate

20 in the control unit or drive. In this way, advantageously, a protective function against vibration, case, etc. of the electronic control device 100 can be realized. A temporary, force-free fixing of the circuit carrier 20 with the housing 10 in the z-direction until the pasty heat-conducting medium 42 has hardened is preferably effected by simple clamping or fixing elements 50 which do not apply any additional mechanical forces or deformations to the circuit carrier 20. For this purpose, for example, a dowel (Figure 4) may be provided with projecting tracks arranged on a circumference of the dowel acting as a kind of barb, a plastic sleeve (Figure 6) or a metallic contact spring (Figure 8). By means of the contact spring, an electrical contacting of the power component 30 with the circuit carrier 20 can advantageously also be realized. FIGS. 5, 7 and 9 show the aforementioned fixing elements 50 in the circuit carrier 20.

In this way, a distance set in the z-direction between the circuit carrier 20 and the housing 10 during an entire

Manufacturing process of the electronic control device 100 are met. After the force-free positioning of the circuit carrier 20 with the housing 10, the paste-like heat transfer medium 40 can be inserted.

10 shows a further embodiment of the fixing element 50 in the form of a snap element or hook. It can be seen that different heights of the circuit carrier 20 can be realized within the housing 10, whereby depending on the altitude of the circuit carrier 20, the snap hooks more or less unfolds. Dashed lines indicate two potential altitudes of the circuit carrier 20 in the z direction and two potential skew positions of the snap hook. This is made possible by a slope of the snap-action hook, which contacts the circuit carrier 20 and holds it in a play-free position by means of a spring action. A required for the snap hook holding force by means of the

Circuit carrier 20 is held in position, via a suitable

Design of the snap hook can be realized.

1 1 shows a perspective view of a complete circuit group with circuit carrier 20, fixing elements 50 and housing 10. The electronic power component 30 arranged on the underside of the circuit carrier 20 and fixed by means of the fixing elements 50 is not discernible. FIG. 12 shows a basic sequence of an embodiment of the method according to the invention.

In a step 200, force-free fixing of a circuit carrier 20 with an electronic power component 30 relative to a housing 10 is performed.

In a step 210, at least partially a pasty heat-conducting medium 40 is arranged on one side of the circuit carrier 20, on which the electronic power component is arranged.

In a step 220, the housing 10 is closed with a housing cover.

In a step 230, the heat-conducting medium 40 is cured.

In summary, the present invention proposes an electronic control device and a method for producing an electronic control device, which enable improved heat dissipation and improved fixation of an electronic slug-up component arranged on a printed circuit board of the control device.

This is made possible by a force-free fixing of the circuit carrier to the housing before inserting a thermal paste, whereby the thermal paste can be applied with a small layer thickness. As a result, on the one hand, optimized heat dissipation is made possible and, on the other hand, an optimized fixation of the power component within the housing is made possible.

Realized in this way is an optimized, integrated integration concept of an electronic power component in an electric drive with the smallest possible gap between the power device and a heat sink, without generating external forces on solder joints. Advantageously can be reduced in this way a thermal resistance and a functional integration of the mechanical attachment of the Circuit carrier in the housing by means of a Wärmeleitpaste be performed.

According to further embodiments, the support of the circuit carrier 20 relative to the housing 10 is not limited to the three-point support. The support of the circuit carrier 20 relative to the housing 10 can be effected by means of a plurality of contact areas. The bearing areas are formed by housing ribs 1 1 and at least one power component 30. However, the bearing areas can also by several power devices 30 or

Housing ribs 1 1 are formed.

Although the invention has been described above with reference to specific embodiments, it is by no means limited thereto. Thus, those skilled in the art will also realize embodiments which are not previously or only partially disclosed without deviating from the gist of the invention.

Claims

claims

1 . An electronic control device (100), comprising:

a housing (10);

a circuit carrier (20) with a arranged thereon

electronic power component (30);

wherein the circuit carrier (20) and the electronic

Power component (30) by means of a heat transfer medium (40) with the housing (10) are contacted;

wherein heat of the power component (30) can be dissipated away from the circuit carrier (20); and

wherein the circuit carrier (20) in the housing (10) by means of the heat transfer medium (40) is fixed.

2. Electronic control device (100) according to claim 1, characterized in that the circuit carrier (20) with the electronic power component (30) relative to the housing (10) by means of at least three

Support areas is positioned, wherein at least one support area between the housing (10) and the electronic power component (30) is formed.

3. Electronic control device (100) according to claim 2, characterized in that at least one of the three support areas as a housing rib (1 1) of the housing (10) is formed.

4. Electronic control device (100) according to claim 2 or 3, characterized in that the circuit carrier (20) with the electronic power component (30) relative to the housing (10) by means of three

Support areas is positioned, wherein a support area formed between the housing (10) and the electronic power device (30) is, and wherein two bearing areas as housing ribs (1 1) of the housing (10) are formed.

5. Electronic control device (100) according to one of the preceding

Claims, characterized in that by means of at least one

Spacer (1 1, 31) a defined distance between a surface of the electronic power device (30) and the housing (10) is made.

6. Electronic control device (100) according to claim 5, characterized

characterized in that the at least one spacer (31) on

Power component (30) is formed.

7. Electronic control device (100) according to claim 5 or 6, characterized in that the at least one spacer as a

Housing rib (1 1) of the housing (10) is formed.

8. Electronic control device (100) according to one of the preceding

Claims, characterized in that by means of fixing elements (50) of the circuit carrier (20) with the housing (10) during the curing of the originally pasty Wärmeleitmediums (40) is fixed without force.

9. Electronic control device (100) according to claim 8, characterized

in that the fixing elements (50) comprise at least one of the following group: plastic sleeve, dowel, contact spring,

Snap element.

10. A method of manufacturing an electronic control device (100), comprising the steps of:

Force-free fixing of a circuit carrier (20) with a

electronic power device (30) relative to a housing (10); At least partially placing a pasty heat conducting medium (40) on one side of the circuit carrier (20) on which the electronic power component (30) is arranged;

- Closing the housing (10); and

Curing the Wärmeleitmediums (40).

1 1. The method of claim 10, wherein the pasty Wärmeleitmedium (40) is additionally arranged at least partially on one side of the circuit carrier (20), which is opposite to the side with the power component (30).

12. The method of claim 10 or 1 1, wherein the force-free fixing of the circuit carrier (20) by means of fixing elements (50) is performed.

13. The method according to any one of claims 10 to 12, wherein between the

Housing (10) and the circuit carrier (20) two bearing areas and between the housing (10) and the electronic power device (30) a support area are formed.