公开(公告)号：GB2269335A

公开(公告)日：1994-02-09

申请号：GB9216526

申请日：1992-08-04

Applicant: IBM

Inventor： BOYD ALEXANDER ,  FRENCH WILLIAM ,  LEES STEWART P ,  MURRAY KENNETH SKENE ,  ROBERTSON BRIAN L

IPC: H01L21/00 ,  H01L21/48 ,  H05K3/34 ,  H05K13/04 ,  B23K3/06

Abstract: Solder particles 220 are deposited onto metallised 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 pickup 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 metallised contacts on the substrate. The head 211 is the 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, levelled and again coated with flux. An integrated circuit chip is then placed on the levelled reliefs 501 and the reliefs reflowed again to attach the chip onto the contacts 302.