Single step solder process

• US 4,761,881 A
• Filed: 09/15/1986
• Issued: 08/09/1988
• Est. Priority Date: 09/15/1986
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Bora, Muhammad-Yusuf J., Hoebener, Karl G.
• Primary Examiner(s): Eley, Timothy V.
• Assistant Examiner(s): Arbes, Carl J.
• Application Number:
  US06/907,266
• Time in Patent Office: 694 Days
• Field of Search: 29/832, 29/840, 174/68.5, 361/400, 128/180.1
• US Class Current: 29/840
• CPC Class Codes: B23K 1/20 Preliminary treatment of work or areas to be soldered, e.g. in respect of a galvanic coating preparation of surfaces in particular ways, see the relevant classes for the treatments or the materials treated, e.g. C04B, C23C
• CPC Class Codes: B23K 2101/40 Semiconductor devices
• CPC Class Codes: H05K 2201/10636 Leadless chip, e.g. chip capacitor or resistor
• CPC Class Codes: H05K 2203/045 Solder-filled plated through-hole [PTH] during processing wherein the solder is removed from the PTH after processing
• CPC Class Codes: H05K 2203/1484 Simultaneous treatments, e.g. soldering lead-in-hole components simultaneously with surface mounted components
• CPC Class Codes: H05K 2203/1572 Processing both sides of a PCB by the same process; Providing a similar arrangement of components on both sides; Making interlayer connections from two sides
• CPC Class Codes: H05K 3/305 Affixing by adhesive
• CPC Class Codes: H05K 3/3415 on both sides of the substrate or combined with lead-in-hole components
• CPC Class Codes: H05K 3/3447 Lead-in-hole components H05K3/3415 takes precedence
• CPC Class Codes: H05K 3/3485 Applying solder paste, slurry or powder thick film methods for applying conductive paste or ink patterns H05K3/12
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/49144 by metal fusion

Abstract

A technique is disclosed for attaching a variety of device types to the same side of a printed circuit board including a single solder application step for both surface mountable and leaded components, placement of the devices, drying of the solder and solder reflow.

Claims

1. An improved method of surface mountable components to both sides and leaded components to one side of a printed circuit board having first and second sides comprising the sequential steps of:

screening solder paste on lands for surface mount components located on the first side of the board;

depositing adhesive on surface mount components receiving sites located on the first side of the board;

placing the surface mount components on the first side of the board;

curing the deposited adhesive;

inverting the board;

screening solder paste on surface mount component lands and into the through hole locations on the second side of the board;

placing components on the second side of the board;

drying the screened solder paste;

reflowing the solder; and

cleaning the board.

2. The method of claim 1 wherein the drying step comprises using convection heat for drying solder paste associated with all component types.