Browse Prior Art Database

Additional Support for Surface Mount Components which Overhang the Card Edge

IP.com Disclosure Number: IPCOM000118972D
Original Publication Date: 1997-Oct-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Cox, WL: AUTHOR [+4]

Abstract

Disclosed is a method for ensuring parallelism of components that overhang the edge of the card during card processing. This method utilizes solder paste on a removable tab segment of a Printed Circuit Board (PCB) to support the component.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 87% of the total text.

Additional Support for Surface Mount Components which Overhang the
Card Edge

      Disclosed is a method for ensuring parallelism of components
that overhang the edge of the card during card processing.  This
method utilizes solder paste on a removable tab segment of a Printed
Circuit Board (PCB) to support the component.

      As shown in Figs. 1 and 2, many components (1) such as
connectors, switches, potentiometers, etc., are designed to overhang
the edge of a PCB (2).  The center of gravity of these components is
frequently near or beyond the edge (3) of the board.  This presents a
unique challenge with surface mount components because the leads (4)
do not provide adequate support, allowing the components to tilt
relative to the board surface during processing.

      The problem is solved by applying solder paste (5) onto a
removable tab segment (6) of the PCB, thus assuring planarity of a
projecting component that is also soldered at its other end to the
circuitry (7) on the PCB.

      The leads (4) of the components (1) (which may be of the
surface mount type) are typically placed on top of solder paste (5).
When the solder paste reflows, the leads are drawn down into the
solder.  In order for the component to remain parallel to the PCB
(2), it is important that the support device (8) for the component
move down  with the leads.  This can be accomplished by providing a
pad (9) on the  added card material which will have solder paste (5)
appli...