Browse Prior Art Database

Sasmat (solder Attached Solder Mask Application Technology)

IP.com Disclosure Number: IPCOM000102851D
Original Publication Date: 1990-Mar-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 32K

Publishing Venue

IBM

Related People

Hwang, IK: AUTHOR

Abstract

Disclosed is a process to eliminate solder paste screening process for Surface Mount Technology (SMT).

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This is the abbreviated version, containing approximately 100% of the total text.

Sasmat (solder Attached Solder Mask Application Technology)

      Disclosed is a process to eliminate solder paste screening
process for Surface Mount Technology (SMT).

      The disclosed process can achieve very fine pitched (less than
.025") SMT assembly process, and it also can combine solder mask
(procoat) process with solder preform process.  It starts with Sn/Pb
foil which was laminated on the photo imageable dry film.

      Sn/Pb foil shall be patterned according to the pad design
layout of printed circuit board (PCB).

      After transferring patterned SASMAT film to the PCB, the Sn/Pb
shall be reflowed with Infra-Red (IR) or vapor phase reflow process.
While Sn/Pb pads are making solder fillet, the solder mask can be
reflowed further and cured completely (See Fig. 1 for details.)

      Disclosed anonymously.