Richardson, TX --  It's solder bumping, not jetting or gold stud bumping. CVI (www.covinc.com) can now bump single die and partial wafers with solder alloys that are representative of final production. Available alloys include SnPb (eutectic), SAC, Pb-rich, InPb and AuSn.
 
Bumping helps in high-speed, high-power applications that need quick turn to validate design, and helps provide better test simulation prior to final design. When cycle time is important, cost is critical and resources are limited, bumping a few die at a time can be effective to evaluate a design.
 
The process is applicable to traditional or MEMS components, and bumps can be applied to a substrate or die. Bump-to-bump variability is reportedly reduced compared to other processes such as solder jetting, screen-printing or electroplating. The traditional prototype method of using gold studs followed by thermocompression or thermosonic bonding can be eliminated.
 
The company can also attach solder balls to bare Al bond pads. The same hardware can be used to bump a die with various alloys to evaluate lead-free solutions. Alternating pads on the die can be bumped with differing alloys or geometry, allowing electromigration studies within the same die or within one wafer. This also reduces lot-to-lot and wafer-to-wafer variation.
 
The process is said to eliminate variables such as paste viscosity, metal load changes, missing bumps, voiding, and changes in size and planarity.
 
CVI can accommodate individual die bumping, partial wafer bumping, or die repair with various alloy compositions. Contact Terence Collier for more information: tqcollier@covinc.com.