Hughes Electronics Corporation

The Boeing Company

Ching P Lo

Daniel A Huang

Pete Hudson

Richard Fanucchi

Steven R Felstein

Lydia H Simanyi

Gregory L Mayhew

Shih Chou

A circuit assembly has a heat sink assembly and a chip scale package assembly. The chip scale package assembly has an integrated circuit die coupled to a first printed wiring board. The heat sink assembly has an integrated circuit die coupled to a second printed wiring board. Preferably, the heat sink assembly and the chip scale package assembly are assembled separately then assembled together. The circuit pads on the first printed wiring board correspond with circuit pads on the second printed wiring board. The circuit pads may be coupled together by solder or adhesive bonding. The circuit pads on the first printed wiring board may have solder balls formed of high temperature solder that do not melt when the heat sink assembly is assembled with chip scale package assembly. The solder balls allow chip scale package assembly to maintain a predetermined distance from the circuit pads on the second printed wiring board.

Chip scale packaging on CTE matched printed wiring boards

A chip-on-board electronic device includes an electronic device die affixed to a printed circuit board, and electrically interconnected thereto by wirebonds. The electronic device is protected by coating it with a layer of silicon oxynitride and, optionally, an overlying thin layer of a conformal coating such as parylene. Under some circumstances, a protective layer of an organic material may be used instead of the layer of silicon oxynitride. The chip-on-board electronic device may be protected with an overlying layer of the conformal coating.

Preparation of passivated chip-on-board electronic devices

A reworkable circuit board assembly including a flip chip adapted for removal in the event of a failure and a method for fabricating the same is disclosed. The reworkable circuit board assembly includes a heat sink having a coefficient of thermal expansion substantially matched to the coefficient of thermal expansion of the flip chip. It also includes a deformable circuit board having a first side and a second side, wherein the first side is secured to a side of the heat sink in thermal communication therewith. The flip chip is bonded to the second side of the deformable circuit board without underfill or with weak bond strength underfill to facilitate removal of the flip chip in the event of a rework.

Reworkable circuit board assembly including a reworkable flip chip

Growing community of inventors

Rancho Palos Verdes, CA, United States of America

Ching P Lo