Out in Front: September 12, 1996

Increased board density and IC package pin count are taxing the ability of current technology to provide cost-effective IC packages. Two companies have developed products that should help solve some of these packaging problems. The first, ProLinx Labs, has announced ViperBGA (VBGA) substrates for making ball-grid array (BGA) packages with up to 696 pins. ProLinx uses a photoimageable via, called a Micro-Filled Via, to produce package substrates at a cost of around $0.01 per connection (ball). Micro-Filled Via technology lets manufacturers make IC package substrates without drilling the vias, resulting in a cheaper manufacturing process. This technology also allows via-in-pin layouts, which permits staggered-bonding- pad configurations. Staggered bonding pads mean shorter bond wires, decreasing chip-to-board delays.

ViperBGA packages offer additional performance advantages. You can have multiple substrate layers for more efficient pad-to-ball routing. Multiple layers also let you use ground and power planes for better electrical and thermal performance compared with standard PQFP or plastic BGA (PBGA) packages. ProLinx claims a 5 to 6W power dissipation without forced air- flow for a 352-ball array package, along with smaller self-inductance and self-capacitance than those of comparable-pin-count PQFP or PBGA packages. ProLinx also has PC-based design tools to place and route package substrates and to model package performance. Prices for the these tools are $2495 for the VBGA Designer and $495 for the VBGA Specifier.

Nitto Denko America recently announced ASMAT (Application Specific Material), a microbumped packaging technology for chip-scale packaging (CSP). With CSP, you can mount high-performance chips at higher densities, making more efficient use of pc-board area. ASMAT combines a fine-pattern processing technology for flexible circuits with precision through-hole and bump-forming technologies. The combination supports packages with as many as 300 I/O pins and provides surface protection of the chip at the same time connections are made during chip mounting in the package. In addition, chip packages made with ASMAT are smaller and thinner than commonly used PQFPs. Nitto Denko plans to license ASMAT to semiconductor manufacturers worldwide.

—by Jim Lipman

ProLinx Labs, San Jose, CA. (408) 227-0707, fax (408) 227-6529.

Nitto Denko America, San Jose, CA. (408) 432-5400, fax (408) 432-5480.