Co-processing of adhesive curing and solder reflow in an electronic assembly operation
AssigneeHughes Electronics Corporation
InventorsMark A. Weaver, Lynn E. Long, Thomas Martinez, Eric J. Shinaver
Life of this patent
Estimating the term…
Abstract
An electronic assembly is fabricated by tinning a solder to the electrical bonding pads of a printed circuit board, and applying an adhesive, preferably a filled polyurethane adhesive, to the component that is to be bonded to the printed circuit board. The component is contacted to its bonding location on the printed circuit board, and the electrical contact on the component is contacted to the tinned bonding pads. The assembly is heated in a single solder temperature/time reflow cycle to simultaneously cure the adhesive and solder the electrical contacts to the bonding pads.
Claims20
A method of fabricating an electronic assembly, comprising the steps of:
- furnishing a support having an electrical bonding pad thereon;
- furnishing metallic solder having a solder temperature/time reflow cycle;
- tinning the solder to the electrical bonding pad of the support;
- furnishing an electronic component having an electrical contact thereon;
- furnishing an adhesive having an adhesive temperature/time curing cycle permitting the adhesive to cure during the solder temperature/time reflow cycle;
- applying the adhesive to at least one of the component and a bonding location on the support to which the component is to be attached;
- contacting the component to the bonding location and the electrical contact to the electrical bonding pad;
- and thereafter
- heating the component and the support to an elevated temperature following the solder temperature/time reflow cycle so that, in a single heating cycle, the adhesive is cured and the solder is simultaneously reflowed.
A method of fabricating an electronic assembly, comprising the steps of:
- furnishing a printed circuit board having an electrical bonding pad thereon;
- furnishing lead-tin eutectic solder;
- tinning the solder to the electrical bonding pad of the printed circuit board;
- furnishing an electronic component having an electrical contact thereon;
- furnishing a filled polyurethane-precursor adhesive;
- applying the adhesive to at least one of the component and a bonding location on the printed circuit board to which the component is to be attached;
- contacting the component to the bonding location and the electrical contact to the electrical bonding pad;
- and thereafter heating the component and the printed circuit board to an elevated temperature following a solder temperature/time reflow cycle for the lead-tin eutectic solder.
A method of fabricating an electronic assembly, comprising the steps of:
- furnishing a printed circuit board having an electrical bonding pad thereon;
- furnishing lead-tin eutectic solder;
- tinning the solder to the electrical bonding pad of the printed circuit board;
- furnishing an electronic component having an electrical contact thereon;
- finishing a filled adhesive, wherein the adhesive has a total mass loss that does not exceed 1.0 percent and a proportion of collected volatile condensable material of not more than 0.10 percent, when tested by the method of ASTM E595, the adhesive has a glass transition temperature no greater than about −60° C., and the adhesive has a thermal conductivity of greater than about 0.35 BTU/hrft° F.;
- applying the adhesive to at least one of the component and a bonding location on the printed circuit board to which the component is to be attached;
- contacting the component to the bonding location and the electrical contact to the electrical bonding pad;
- and thereafter
- heating the component and the printed circuit board to an elevated temperature following a solder temperature/time reflow cycle for the lead-tin eutectic solder.
Dependencies are inferred from the claim text.