Method of producing an overmolded electronic module with a flexible circuit pigtail

• US 7,739,791 B2
• Filed: 10/26/2007
• Issued: 06/22/2010
• Est. Priority Date: 10/26/2007
• Status: Active Grant

• Current Assignee: Delphi Technologies Ip Limited (BorgWarner Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Brandenburg, Scott D., Laudick, David A, Oberlin, Gary E.
• Primary Examiner(s): PHAN, THIEM D
• Application Number:
  US11/978,063
• Publication Number:
  US 20090106974A1
• Time in Patent Office: 970 Days
• Field of Search: 298/56, 298/27, 298/40, 298/41, 298/32, 174/529, 174/536, 174/551, 174/564, 257/666, 257/667, 257/787, 257/E23.092, 257/E23.125
• US Class Current: 29/856
• CPC Class Codes: B29C 45/14377 using an additional insert, e.g. a fastening element
• CPC Class Codes: B29C 45/14418 Sealing means between mould and article
• CPC Class Codes: B29C 45/14639 for obtaining an insulating effect, e.g. for electrical components
• CPC Class Codes: B29C 45/14836 Preventing damage of inserts during injection, e.g. collapse of hollow inserts, breakage B29C45/14434 takes precedence
• CPC Class Codes: B29C 45/72 Heating or cooling
• CPC Class Codes: H05K 1/118 specially for flexible printed circuits, e.g. using folded portions
• CPC Class Codes: H05K 1/147 at least one of the printed circuits being bent or folded, e.g. by using a flexible printed circuit H05K1/148 takes precedence
• CPC Class Codes: H05K 2201/0239 Coupling agent for particles using a coupling agent to improve the adhesion between an insulating substrate and a metal H05K3/389
• CPC Class Codes: H05K 2203/1121 Cooling, e.g. specific areas of a PCB being cooled during reflow soldering details related to cooling of mounted components H05K1/0203
• CPC Class Codes: H05K 2203/1316 Moulded encapsulation of mounted components
• CPC Class Codes: H05K 3/284 for encapsulating mounted components H05K1/185 takes precedence
• CPC Class Codes: H05K 3/361 Assembling flexible printed circuits with other printed circuits
• CPC Class Codes: H05K 5/065 sealed by encapsulation, e.g. waterproof resin forming an integral casing, injection moulding
• CPC Class Codes: Y10T 29/49121 Beam lead frame or beam lead device
• CPC Class Codes: Y10T 29/49144 by metal fusion
• CPC Class Codes: Y10T 29/49146 with encapsulating, e.g., potting, etc.
• CPC Class Codes: Y10T 29/49172 by molding of insulating material
• CPC Class Codes: Y10T 29/5193 Electrical connector or terminal

Abstract

A method of producing an overmolded electronic assembly including a circuit board and a flexible circuit interconnect by fixturing the assembly in a mold cavity such that a portion of the flexible circuit protrudes from the mold, and providing a compressible elastomeric interface between the mold and the flexible circuit to seal off the mold cavity and protect the flexible circuit from damage due to the clamping force of the mold. The portion of the flexible circuit within the mold cavity is pre-coated with a material that ensures good adhesion with the molding compound, and a heat exchanger thermally coupled to the portion of the flexible circuit that protrudes from the mold protects the flexible circuit from damage due to thermal conduction from the mold and mold compound.

Claims

1. A method of producing an overmolded electronic assembly, comprising the steps of:

connecting one end of a flexible circuit interconnect to an electronic assembly;

fixturing the electronic assembly and flexible circuit interconnect in a mold cavity defined by upper and lower mold halves such that a portion of said flexible circuit interconnect extends out of said mold cavity and passes between said upper and lower mold halves;

providing an upper compressible elastomeric pad on said upper mold half and a lower compressible elastomeric pad on said lower mold half, and clamping the mold halves together such that said flexible circuit interconnect is sandwiched between said upper and lower compressible elastomeric pads to isolate said flexible circuit interconnect from said mold halves and to seal said mold cavity around said flexible circuit interconnect prior to injection of encapsulant material into said mold cavity;

positioning a heat exchanger adjacent said mold halves for receiving an end portion of said flexible circuit interconnect to remove heat from said flexible circuit interconnect;

positioning a thermal barrier between said heat exchanger and said mold halves;

injecting encapsulant material into said mold cavity to overmold said electronic assembly and a portion of said flexible circuit interconnect;

removing said overmolded electronic assembly from said mold cavity upon curing of said encapsulant material; and

removing said heat exchanger and said thermal barrier when said overmolded electronic assembly is removed from said mold cavity.