Method of assembling power circuits and control circuits on several levels in the same module and a module thus obtained

• US 4,858,074 A
• Filed: 04/22/1988
• Issued: 08/15/1989
• Est. Priority Date: 04/22/1987
• Status: Expired due to Fees

• Current Assignee: Power Compact Societe Anonyme
• Original Assignee: Power Compact Societe Anonyme
• Inventors: Landais, Jean-Louis, Mallet, Jean-Louis
• Primary Examiner(s): Goldberg, Howard N.
• Assistant Examiner(s): Arbes, Carl J.
• Application Number:
  US07/184,955
• Time in Patent Office: 480 Days
• Field of Search: 361/412-415, 361/383, 361/386, 361/387, 361/388, 361/395, 29/830, 29/832, 174/68.5
• US Class Current: 423/447.4
• CPC Class Codes: H01L 23/24 solid or gel at the normal operating temperature of the device H01L23/3135 takes precedence
• CPC Class Codes: H01L 23/3135 Double encapsulation or coating and encapsulation
• CPC Class Codes: H01L 23/48 Arrangements for conducting electric current to or from the solid state body in operation, e.g. leads, terminal arrangements ; Selection of materials therefor
• CPC Class Codes: H01L 25/072 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 5/0095 hermetically-sealed
• CPC Class Codes: H05K 7/1432 specially adapted for power drive units or power converters
• CPC Class Codes: H05K 7/14322 wherein the control and power circuits of a power converter are arranged within the same casing
• CPC Class Codes: Y10T 29/49126 Assembling bases

Abstract

The invention provides a method for assembling power circuits and control circuits on several levels in the same module and the module thus obtained, which method consists in grouping on one so called low level the power circuits (1) in grouping on at least one so called mid-height level (3) the control circuits, in forming the electric connections between the circuits of the two levels of elements in the form of helical springs (4) made from a relatively rigid and weldable metal material, disposed vertically, in welding the lower ends of the springs (4) to the appropriate positions of the circuits of the low level (1) while holding the springs in position by means of a guide plate (13), in fixing the wall (6) of the module, in placing inside the wall, by means of positioning projections, (8) the substrate (3) carrying the control circuits, in welding the upper ends of the springs (4) to the appropriate positions on the upper face of the substrate and, finally, in filling the inside of the wall with resin.

Claims

1. A power module having power circuits and control circuits, comprising:

a ceramic substrate fixed to a heat dissipating base;

a plurality of power circuits mounted to said ceramic substrate to form a lower level;

a plurality of control circuits mounted to a desired substrate to form a middle level over said lower level;

at least one electrically conductive spring means providing electrical connection between said lower and middle levels;

said electrically conductive spring means being disposed substantially perpendicular to said lower and middle levels, said electrically conductive spring means being welded to desired positions in said lower level and said middle level; and

at least one resin material embedding said lower and middle levels.

2. The power module according to claim 1, further comprising a wall enclosing said lower and middle levels, said wall having a seat formed thereon for receiving said middle level substrate.

3. The power module according to claim 2 wherein said seat forms a dovetailed joint.

4. The power module according to claim 1, wherein said resin material is a soft resin material for absorbing any thermal expansion which occurs in said power circuits and wherein said electrically conductive spring means is a helical spring.

5. The power module according to claim 1, wherein said resin material comprises:

a first layer of a soft resin material for absorbing any thermal expansion which occurs in said power circuits;

said first layer embedding said lower level; and

a second layer of a harder resin material embedding said middle level.

6. A method of assembling a power module having power circuits and control circuits, comprising:

fixing a ceramic substrate to a heat dissipating base;

mounting a plurality of power circuits to said ceramic substrate a form a lower level;

mounting a plurality of control circuits to a desired substrate to form a middle level over said lower level;

electrically connecting said lower and middle levels with at least one electrically conductive spring means;

fixing a wall which encloses said lower and middle levels to said heat dissipating base; and

providing the portion of the module bounded by said wall and said base with at least a first layer of a soft resin material to absorb any thermal expansion which occurs in said power circuits.

7. The method according to claim 6, further comprising:

welding a lower end of said spring means to a desired position in said lower level;

positioning said spring means with a guide plate means, said guide plate means having holes disposed therein to receive said spring means, said spring means comprising a helical spring; and

welding an upper end of said spring means to a desired position on said middle level.

8. The method according to claim 6, further comprising forming a seat on said wall to receive said middle level substrate.