Pac Tech introduced at Productronica in November, 2000, a new machine for solder bumping flip chip die and wafers which combines the advantages of both solder sphere placement and solder jetting.

The SB²-Jet builds upon Pac Tech's proven technology for conventional solder sphere placement, which laser-reflows the sphere after placing it on the pad. However, the new machine uses laser heating to reflow the ball before it reaches the substrate, so that it becomes a molten solder jet before contacting the pad.

Click HERE for a 37k .jpg photo of 350 micron jetted bumps on a BGA strip.

This new approach allows high speed, flux free non-contact placement and reflow of solder spheres at rates up to 10 balls per second. In addition, the technique minimizes heat transfer to the substate and to the surrounding components, making it ideal for rework and repair, as well as for initial solder bump placement onto individual die or wafers.

Solder sphere diameters may be from 100 to 760 micrometers. Available alloys include eutectic PbSn, SnAg, SnAgCu, and AuSn. The machine is suitable for flip chip, BGA, CSP, and optoelectronic devices. Applications include Medical, Telecommunications, Optoelectronics, MEMS, Automotive, and 3-D interconnect.