Overmolded electronic package including circuit-carrying substrate

• US 6,779,260 B1
• Filed: 03/28/2003
• Issued: 08/24/2004
• Est. Priority Date: 03/28/2003
• Status: Expired due to Term

• Current Assignee: Delphi Technologies Ip Limited (BorgWarner Incorporated)
• Original Assignee: Delphi Technologies, Inc. (Aptiv PLC)
• Inventors: Myers, Bruce A., Degenkolb, Thomas A., Brandenburg, Scott D.
• Primary Examiner(s): Arbes, Carl J.
• Application Number:
  US10/401,850
• Time in Patent Office: 515 Days
• Field of Search: 298/27, 298/32, 298/40, 298/41, 174/52.2, 174/52.4
• US Class Current: 29/841
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/85399 Material
• CPC Class Codes: H01L 23/3121 a substrate forming part of the encapsulation
• CPC Class Codes: H01L 23/4334 Auxiliary members in encapsulations H01L23/49568 takes precedence
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 24/48 of an individual wire connector
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/00015 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed as prior art
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/1815 Shape
• CPC Class Codes: H01L 2924/207 Diameter ranges
• CPC Class Codes: H01R 13/504 different pieces being moulded, cemented, welded, e.g. ultrasonic, or swaged together
• CPC Class Codes: H01R 13/665 with built-in electronic circuit H01R13/70, H01R13/719 take precedence
• CPC Class Codes: H01R 43/24 : Assembling by moulding on contact members
• CPC Class Codes: H05K 3/0058 : Laminating printed circuit boards onto other substrates, e.g. metallic substrates H05K1/0281 takes precedence
• CPC Class Codes: H05K 3/284 : for encapsulating mounted components H05K1/185 takes precedence
• CPC Class Codes: Y10T 29/49121 : Beam lead frame or beam lead device
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49144 : by metal fusion
• CPC Class Codes: Y10T 29/49146 : with encapsulating, e.g., potting, etc.

Abstract

An overmolded electronic package includes a circuit-carrying substrate and a connector housing or shroud interconnected via a suitable interconnection arrangement. Some embodiments may include a backplate affixed to the substrate and, in some cases, also to the connector housing or shroud. In some embodiments, the connector housing or shroud may be affixed to the substrate, and in any case the entire subassembly of components is overmolded with a rigidly formable molding compound to bond together all components of the subassembly and form the overmolded electronic package. The subassembly of components with the exception of the backplate may alternatively be overmolded with the molding compound, and a backplate thereafter affixed to the subassembly via a compliant bonding medium.

Claims

1. A method of forming an overmolded electronic package including a circuit-carrying substrate, the method comprising the steps of:

providing a housing defining a cavity therein and defining a connector shroud having a number of electrically conductive leads extending into said cavity;

attaching said housing to a backplate;

attaching said circuit-carrying substrate to said backplate within said housing cavity;

connecting said number of electrically conductive leads to corresponding conductive pads defined on said substrate;

filling said cavity with a rigidly formable molding compound; and

curing said formable molding compound to rigidly bond together said backplate, said substrate and said housing to form said overmolded electronic package.

2. The method of claim 1 wherein the connecting step comprises wirebonding said number of electrically conductive leads to said corresponding conductive pads defined on said substrate.

3. The method of claim 1 further including the step of applying an adhesion promoting layer to a circuit-carrying side of said substrate prior to the filling step, said adhesion promoting layer promoting adhesion between said circuit-carrying side of said substrate and said formable molding compound.

4. The method of claim 1 wherein a circuit-carrying side of said substrate has at least one flip chip mounted thereto, said at least one flip chip and said substrate defining a space therebetween;

and wherein said formable molding compound is configured to flow between said at least one flip chip and said substrate and fill said space prior to the curing step.

5. The method of claim 1 wherein said formable molding compound is configured to exhibit a coefficient of thermal expansion that is near that of said substrate.

6. A method of forming an overmolded electronic package including a circuit-carrying substrate, the method comprising the steps of:

providing a connector shroud having a number of electrically conductive leads extending therethrough;

attaching said connector shroud to one of a backplate and the circuit-carrying substrate;

attaching the circuit-carrying substrate to said backplate;

connecting said number of electrically conductive leads to corresponding conductive pads defined on said substrate; and

overmolding at least said connector shroud and said circuit-carrying substrate with a rigidly formable molding compound to form said overmolded electronic package.

7. The method of claim 6 wherein the step of attaching said connector shroud comprises attaching said connector shroud only to said backplate;

and wherein the overmolding step includes overmolding said connector shroud, said circuit-carrying substrate and said backplate with said rigidly formable molding compound to form said overmolded electronic package.

8. The method of claim 6 wherein the step of attaching said connector shroud comprises attaching said connector shroud only to said circuit-carrying substrate;

and wherein the overmolding step includes overmolding said connector shroud, said circuit-carrying substrate and said backplate with said rigidly formable molding compound to form said overmolded electronic package.

9. The method of claim 6 wherein the step of attaching said connector shroud comprises attaching said connector shroud only to said circuit-carrying substrate;

and wherein the overmolding step includes overmolding only said connector shroud and said circuit-carrying substrate with said rigidly formable molding compound to form said overmolded electronic package;

and wherein the step of attaching said circuit-carrying substrate is executed after the overmolding step.

10. The method of claim 6 wherein the connecting step comprises wirebonding said number of electrically conductive leads to said corresponding conductive pads defined on said substrate.

11. The method of claim 6 further including the step of applying an adhesion promoting layer to a circuit-carrying side of said substrate prior to the overmolding step, said adhesion promoting layer promoting adhesion between said circuit-carrying side of said substrate and said formable molding compound.

12. The method of claim 6 wherein a circuit-carrying side of said substrate has at least one flip chip mounted thereto, said at least one flip chip and said substrate defining a space therebetween;

and wherein said formable molding compound is configured to flow between said at least one flip chip and said substrate and fill said space.

13. The method of claim 6 wherein said formable molding compound is configured to exhibit a coefficient of thermal expansion that is near that of said substrate.

14. A method of forming an overmolded electronic package including a circuit-carrying substrate, the method comprising the steps of:

attaching the circuit-carrying substrate to a backplate;

providing a connector shroud having a number of electrically conductive leads extending therethrough;

connecting said number of electrically conductive leads to corresponding conductive pads defined on said substrate; and

overmolding at least said connector shroud and said circuit-carrying substrate with a rigidly formable molding compound to form said overmolded electronic package.

15. The method of claim 14 wherein the overmolding step includes overmolding said connector shroud, said circuit-carrying substrate and said backplate with said rigidly formable molding compound to form said overmolded electronic package.

16. The method of claim 14 wherein the overmolding step includes overmolding only said connector shroud and said circuit-carrying substrate with said rigidly formable molding compound to form said overmolded electronic package;

and wherein the step of attaching said circuit-carrying substrate is executed after the overmolding step.

17. The method of claim 14 wherein the connecting step comprises:

providing a solder mass between each of said number of electrically conductive leads and said corresponding conductive pads defined on said substrate; and

reflowing said solder masses to electrically and mechanically connect said number of electrically conductive leads to said corresponding conductive pads defined on said substrate.

18. The method of claim 14 further including the step of applying an adhesion promoting layer to a circuit-carrying side of said substrate prior to the overmolding step, said adhesion promoting layer promoting adhesion between said circuit-carrying side of said substrate and said formable molding compound.

19. The method of claim 14 wherein a circuit-carrying side of said substrate has at least one flip chip mounted thereto, said at least one flip chip and said substrate defining a space therebetween;

and wherein said formable molding compound is configured to flow between said at least one flip chip and said substrate and fill said space.

20. The method of claim 14 wherein said formable molding compound is configured to exhibit a coefficient of thermal expansion that is near that of said substrate.

21. A method of forming an overmolded electronic package including a circuit-carrying substrate, the method comprising the steps of:

providing a connector shroud having a number of electrically conductive leads extending therethrough;

connecting said number of electrically conductive leads to corresponding conductive pads defined on the circuit-carrying substrate;

overmolding said connector shroud and circuit-carrying substrate with a rigidly formable molding compound while leaving at least partially exposed an underside of said connector shroud and an underside of said circuit-carrying substrate; and

attaching a backplate to said undersides of said connector shroud and said substrate after the overmolding step to form said overmolded electronic package.

22. The method of claim 21 wherein the connecting step comprises:

providing a solder mass between each of said number of electrically conductive leads and said corresponding conductive pads defined on said substrate; and

reflowing said solder masses to electrically and mechanically connect said number of electrically conductive leads to said corresponding conductive pads defined on said substrate.

23. The method of claim 21 further including the step of applying an adhesion promoting layer to a circuit-carrying side of said substrate prior to the overmolding step, said adhesion promoting layer promoting adhesion between said circuit-carrying side of said substrate and said formable molding compound.

24. The method of claim 21 wherein a circuit-carrying side of said substrate has at least one flip chip mounted thereto, said at least one flip chip and said substrate defining a space therebetween;

and wherein said formable molding compound is configured to flow between said at least one flip chip and said substrate and fill said space.

25. The method of claim 21 wherein said formable molding compound is configured to exhibit a coefficient of thermal expansion that is near that of said substrate.

26. A method of forming an overmolded electronic package including a circuit-carrying substrate having a number of flip-chip circuits mounted thereto, the method comprising the steps of:

providing a backplate having a number of thermally conductive posts extending therefrom;

attaching the circuit-carrying substrate to said backplate with each of said number of flip-chip circuits mounted to a corresponding one of said number of thermally conductive posts;

providing a connector shroud having a number of electrically conductive leads extending therethrough;

connecting said number of electrically conductive leads to corresponding conductive pads defined on said substrate; and

overmolding said connector shroud, said circuit-carrying substrate and said backplate with a rigidly formable molding compound to form said overmolded electronic package.

27. The method of claim 26 further including the step of applying a formable thermally conductive medium between each of said number of flip-chip circuits and a corresponding one of said number of thermally conductive posts.

28. The method of claim 26 further including the step of attaching said connector shroud to said circuit-carrying substrate.

29. The method of claim 26 further including the step of applying an adhesion promoting layer to a circuit-carrying side of said substrate prior to the overmolding step, said adhesion promoting layer promoting adhesion between said circuit-carrying side of said substrate and said formable molding compound.

30. The method of claim 26 wherein each of said number of flip-chip circuits and said substrate define a space therebetween;

and wherein said formable molding compound is configured to flow between said number of flip-chip circuits and said substrate and fill said spaces.

31. The method of claim 26 wherein said formable molding compound is configured to exhibit a coefficient of thermal expansion that is near that of said substrate.

32. The method of claim 26 wherein the connecting step comprises:

providing a solder mass between each of said number of electrically conductive leads and said corresponding conductive pads defined on said substrate; and

reflowing said solder masses to electrically and mechanically connect said number of electrically conductive leads to said corresponding conductive pads defined on said substrate.