Mcnc

Edward K Yung

Glenn A Rinne

Iwona Turlik

Nicholas G Koopman

An integrated circuit chip having solder bumps thereon may be tested using a temporary substrate having substrate pads corresponding to locations of the input/output pads on the chip and having a sacrificial conductor layer on the temporary substrate pads. The solder bumps are placed adjacent the corresponding sacrificial metal layer and heated to form an electrical and mechanical connection between the chip and the temporary substrate. The chip is then tested and/or burned-in on the temporary substrate. After testing/burn-in, the sacrificial metal layer is dissolved into the solder bumps by heating. The integrated circuit chip, including a solder bump having the dissolved sacrificial metal layer therein, may be easily removed from the temporary substrate. Solder bumps may also be formed on the temporary substrate and transferred to unbumped chips. Solder bumps with different characteristics may be formed by varying the current-time product to each individual pad of the temporary substrate during a plating operation.

Method of forming differing volume solder bumps

Apparatus for testing, burn-in, and/or programming of integrated circuit

The base of solder bumps is preserved by converting the under-bump metallurgy between the solder bump and contact pad into an intermetallic of the solder and the solderable component of the under-bump metallurgy prior to etching the under-bump metallurgy. The intermetallic is resistant to etchants which are used to etch the under-bump metallurgy between the contact pads. Accordingly, minimal undercutting of the solder bumps is produced, and the base size is preserved. The solder may be plated on the under-bump metallurgy over the contact pad through a patterned solder dam layer having a solder accumulation region thereon. The solder dam is preferably a thin film layer which may be accurately aligned to the underlying contact pad to confine the wetting of the molten solder during reflow. Misalignment between the solder bump and contact pad is thereby reduced. The solder bumps so formed include an intermetallic layer which extends beyond the bump to form a lip around the base of the bump. This lip provides extra protection for the solder bump.

Solder bump including circular lip

Method for testing, burn-in, and/or programming of integrated circuit

Solder bump fabrication method

Growing community of inventors

Carrboro, NC, United States of America

Edward K Yung