Patent Number: 6,254,923

Title: Solder particle deposition

Abstract: Solder particles 220 are deposited onto metallized contacts of a direct chip attach (DCA) site located on a substrate 301. The contacts 302 are coated with a layer of flux 303. A pick up head 211 is positioned in a reservoir 201 of solder particles 220 and particles are attracted to the apertures in the end 213 of the head. The apertures have an arrangement corresponding to the footprint of the metallized contacts on the substrate. The head 211 is positioned adjacent the substrate 301 and the particles 220 released. The particles 220 stick to the flux 303 coated on the contacts 302. The particles are reflowed, leveled and again coated with flux. An integrated circuit chip is then placed on the leveled reliefs 501 and the reliefs reflowed again to attach the chip onto the contacts 302.

Inventors: Boyd; Alexander (Largs, GB), French; William (Glasgow, GB), Lees; Stuart P. (Gourock, GB), Murray; Kenneth Skene (Inverkep, GB), Robertson; Brian L. (Gourock, GB)

Assignee: International Business Machines Corporation

International Classification: H01L 21/02 (20060101); H01L 21/48 (20060101); H05K 3/34 (20060101); H05K 13/04 (20060101); B05D 005/12 ()

Expiration Date: 07/03/2018