Method and apparatus for solder bumping of printed circuit boards

Patent 4752027 Issued on June 21, 1988. Estimated Expiration Date:

February 20, 2007. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

3621564

3713575

3871015

Method and device for the continuous application of a reinforcement layer onto a porous mineral building board
Patent #: 4503096
Issued on: 03/05/1985
Inventor: Specht

Method and apparatus for batch solder bumping of chip carriers
Patent #: 4558812
Issued on: 12/17/1985
Inventor: Bailey , et al.

Circuit chip
Patent #: 4582975
Issued on: 04/15/1986
Inventor: Daughton

Low cost integrated circuit bonding process Patent #: 4661192
Issued on: 04/28/1987
Inventor: McShane

Inventor

Gschwend, Stephen J.

Application

No. 07/017112 filed on 02/20/1987

US Classes:

228/180.22, Lead-less (or "bumped") device228/207, Applying flux228/234.2, Vapor phase heating427/359Roller, drum, or cylinder

Examiners

Primary: Godici, Nicholas P.
Assistant: Skillman, Karen

Attorney, Agent or Firm

Murray; Leslie G.

International Classes

B23K 3/06 (20060101)
H05K 3/34 (20060101)

Abstract

A method and apparatus for preparing printed circuit boards having flattened solder bumps for the mounting of surface mount components is provided. Using well-known techniques, solder paste is screen-printed onto printed circuit boards and reflowed and cleaned to form discrete solder bumps. Using roller machines, the peaks of the solder bumps are flattened and adhesive solder flux is applied to the flattened tops of the solder bumps. The adhesive solder flux holds the surface mount components in position after placement and during vapor phase reflow.