US 5,627,108 A · Solder paste and glue dot-based methods of securing components to a printed circuit board

Abstract

Glue dots are deposited on a substrate side of a partially completed printed circuit board, between pairs of component mounting pads disposed on the substrate and having quantities of solder paste thereon, using a resilient stencil plate having a spaced series of glue discharge openings extending transversely therethrough, and a spaced series of side recesses. The recess side of stencil plate is positioned in a spaced, parallel and opposing relationship with the mounting pad side of the substrate with the plate recesses being aligned with the substrate mounting pads, and the glue discharge openings being aligned with glue leveling pads disposed on the substrate side between adjacent mounting pad pairs. Glue is deposited on the outer stencil plate side and a squeegee blade is moved along the outer stencil plate side to deflect it toward the substrate and force glue through the discharge openings to deposit glue dots thereon when the stencil plate is permitted to return to its undeflected position. As the plate is deflected, its depressions receive and provide clearance for the mounting pads so as not to disturb the solder paste quantities thereon. Electrical components are then pressed against pairs of mounting pads, and the glue dots therebetween, before being subjected to a final soldering process. In this manner the use of a needle type dispensing machine to deposit the glue dots is advantageously avoided.

Claims16

Dependent claims

A method of operatively mounting an electrical component on a spaced pair of electrically conductive mounting pads disposed on a first side of a partially completed circuit board, said method comprising the steps of:

depositing quantities of solder paste on the mounting pads;
providing a stencil plate having a spaced pair of recesses formed in a first side thereof, and a glue discharge opening disposed between and spaced apart from said pair of recesses and extending between the first and second sides of said stencil plate;
positioning said stencil plate in a glue depositing orientation in which said first stencil plate and circuit board sides are in a parallel, opposing relationship with said recesses being aligned with and receiving said mounting pads without appreciably disturbing the quantities of solder paste thereon;
forcing a quantity of glue through said glue discharge opening and onto the first circuit board side;
moving said stencil plate away from the circuit board in a manner leaving a glue dot on the first circuit board side;
and
positioning an electrical component on the first circuit board side by pressing the component against the solder paste quantities and said glue dot.

4 more elements

A method of fabricating a printed circuit board comprising the steps of:

providing a substrate member with a generally planar first side having disposed thereon (1) a mutually spaced series of electrically conductive mounting pads each having an outer side facing transversely away from said first side, and (2) a mutually spaced series of glue leveling pads each disposed between and spaced apart from the mounting pads in a different adjacent pair thereof;
depositing quantities of solder paste on said outer sides of said mounting pads;
providing a stencil plate having opposite first and second sides, a spaced series of glue discharge openings each extending through said stencil plate between said first and second sides thereof, and a spaced series of recesses formed in said first stencil plate side in a mutually spaced relationship with said glue discharge openings,
said spaced series of recesses and glue discharge openings being respectively alignable with said mounting pads and said glue leveling pads when said stencil plate is disposed in a glue depositing orientation relative to said substrate member in which said first sides of said stencil plate and said substrate member are in a parallel, facing relationship, said recesses being sized and configured to receive said mounting pads and the deposited quantities of solder paste thereon without appreciably disturbing the solder paste;
disposing said stencil plate in said glue depositing orientation thereof relative to said substrate member;
and
depositing glue dots on said glue leveling pads by forcing a glue material through said glue discharge openings from said second side of said stencil plate.

4 more elements

Dependencies are inferred from the claim text.

Solder paste and glue dot-based methods of securing components to a printed circuit board

Life of this patent

Solder paste and glue dot-based methods of securing components to a printed circuit board

Life of this patent

Abstract

Claims16