Google Inc.

Cisco Technology, Inc.

Sue Yun Teng

Shinnosuke Yamamoto

Mudasir Ahmad

Emad Samadiani

Padam Jain

Sudharshan Sugavanesh Udhayakumar

Yingshi Tang

Nicholas Chao Wei Wong

Kieran Miller

A compliant pad spacer utilized in a three-dimensional IC packaging is provided. The compliant pad spacer may be utilized to provide adequate support among the substrates or boards, such as packing substrates, interposers or print circuit broads (PCBs), so as to minimize the effects of substrate warpage or structural collapse in the IC packaging. In one example, the compliant pad spacer includes an insulating material, such as silicon-based polymer composites having ceramic fillers disposed therein.

Compliant pad spacer for three-dimensional integrated circuit package

The present disclosure provides for a heatshield that can be actively cooled during a rework process. The heatshield may include a backer plate and a metal plate. A plurality of vents may extend from air inlet ducts to a top surface of the backer plate such that the plurality of vents directs cooling gas forced into the heatshield towards the metal plate and a first ball grid array (BGA) package. The cooling gas may maintain the solder joint temperature of the first BGA package below a reflow temperature and below a solidus temperature to prevent reflow-related solder joint defects from occurring in the first BGA package during rework of a second BGA package.

Cooling heatshield for clamshell BGA rework

The present disclosure provides systems for applying a compression load on at least part of an application specific integrated circuit ('ASIC') ball grid array ('BGA') package during the rework or secondary reflow process. The compression-loading assembly may include a top plate and a compression plate. The compression plate may exert a compression load on at least part of the ASIC using one or more compression mechanisms. The compression mechanisms may each include a bolt and a spring. The bolt may releasably couple the top plate to the compression plate and allow for adjustments to the compression load. The spring may be positioned on the bolt between the top plate and the compression plate and, therefore, may exert a force in a direction away from the top plate and toward the compression plate. The compression load may retain the solder joint and may prevent the solder separation defect during the reflow process.

Compression-loaded printed circuit assembly for solder defect mitigation

The present disclosure provides for a heatshield that can be actively cooled during a rework process. The heatshield may include a backer plate, a metal plate, and/or a package pedestal. The backer plate may include one or more air inlet ports configured to be connected to an air compressor. Air inlet ducts may extend from the air inlet ports through at least a portion of the backer plate. A plurality of vents may extend from the air inlet ducts to a top surface of the backer plate such that the plurality of vents directs cooling gas forced into the heatshield towards the metal plate and a first BGA. The cooling gas may maintain the solder joint temperature of the first BGA package below the reflow temperature and below the solidus temperature of the solder joints to prevent reflow-related solder joint defects from occurring in the first BGA package during rework of a second BGA package.

A technique of monitoring strain on a printed circuit board assembly involves the use of a strain detector mounted on a printed circuit board. The strain detector is formed of a non-ductile material. The strain detector has a narrowed portion forming a weak link that has a characteristic of breaking when a critical strain limit is exceeded. The method of monitoring can include visual or electrical inspection. The electrical inspection can include having a strain monitoring device. The strain monitoring device has a timer connected to at least one strain detector and a memory for storing results connected to the timer. The capacitance of at least one of the strain detectors is sampled and any change in capacitance is recorded to the memory. In one embodiment, a time stamp occurs in the memory based on when an electrical property changes across at least one of the strain detectors.

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Belmont, CA, United States of America

Sue Yun Teng