Motorola Corporation

Compaq Computer Corporation, Inc.

Andrew J Mawer

Thomas H Koschmieder

Terry E Burnette

Ronald D Denton

Timothy M McGuiggan

George H Bumgardner

A semiconductor device ( ) includes a semiconductor die ( ) having electronic circuitry that is connected to a substrate ( ). The substrate ( ) is used to interface the semiconductor die ( ) to a printed circuit board ( ). The substrate ( ) includes a plurality of bonding pads ( ). A first portion of the plurality of bonding pads are soldermask defined (SMD) bonding pads ( ) and a second portion of the plurality of bonding pads are non-soldermask defined (NSMD) bonding pads ( ). Using a combination of SMD and NSMD bonding pads provides the advantages of good thermal cycling reliability and good bending reliability over devices that have only SMD bonding pads or NSMD bonding pads.

Semiconductor device having a ball grid array and method therefor

A technique for minimizing heat-induced chipside solder joint fractures involving BGA (Ball Grid Array) components mounted on a multilayer printed circuit board when the board is passed through a wavesolder oven. The technique involves shielding the chipside solder joints from the effects of conductive heating by covering the through vias positioned underneath the BGA components with an insulating material. The insulating materials include silk screen material, solder mask and KAPTON tape. During wavesolder, the insulating material blocks conductive heat flow from the exposed board face through the vias and into the BGA component landing areas. With the wavesolder heat flow blocked, the BGA landing areas and BGA components experience much less heat deformation, and a much lower solder joint defect rate is achieved. Selection of silk screen, solder mask or KAPTON tape is based on a balance of solder process conditions and effective insulation capability, with the lowest cost, most effective solution preferred.

Masking of circuit board vias to reduce heat-induced board and chip

Growing community of inventors

Austin, TX, United States of America

Andrew J Mawer