Browse Prior Art Database

Transportable Solder Paste Screener Support Plate

IP.com Disclosure Number: IPCOM000119011D
Original Publication Date: 1997-Oct-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 87K

Publishing Venue

IBM

Related People

Barlow, SA: AUTHOR [+3]

Abstract

Disclosed is a device for providing accurate, transportable support of printed circuit cards during the solder paste screening operation. There are several portions to the solution. First is the use of a transportable plate that rides on the transport rails of the screener equipment rather than being attached as part of the internal screener base. The second portion of the solution is to use a conversion of existing process data in a new way, that being to use card Gerber data to design the support plate.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Transportable Solder Paste Screener Support Plate

      Disclosed is a device for providing accurate, transportable
support of printed circuit cards during the solder paste screening
operation.  There are several portions to the solution.  First is the
use of a transportable plate that rides on the transport rails of the
screener equipment rather than being attached as part of the internal
screener base.  The second portion of the solution is to use a
conversion of existing process data in a new way, that being to use
card Gerber data to design the support plate.

      The solution is to use a transportable plate on which either
the cards are directly placed or which allows for cards in workboard
holders to be placed on the plate.  The novelty of this process is
that the plate rides on the screening transport rails into and out of
the screening with the card.

      Since the plates are transportable, there is no risk of
misalignment between the card and support.  Methods which require the
support to be attached inside the screener may result in misalignment
of the support to the card as the screener base is raised which could
cause the support to hit critical components and cause damage.

      The support plates themselves must be sturdy enough to provide
firm support during screening and light enough so that they ride
easily on the screener transport rails.  This is especially important
when the card being supported is mounted in a workboard holder, since
the workboard holder adds mass.  The back side of the screener
support plate  may be relieved by milling away material in order to
reduce its mass.

      General guidelines for design of the support plates include
providing some card retention to hold the card to the plate, complete
removal of support plate material in areas of through-hole paste
application where a build-up of paste would collect on the support
plate and contaminate the side of the cards in contact with the
support plate, and designing support locations so that only the card
itself and  not the components are contacted by the support plate.
This last item  is necessary to prevent potential component damage.

      The support plate manufacture typically starts with a blank of
lightweight, rigid, Electrostatic Discharge (ESD)-safe material such
as aluminum, length and width compatible with screener r...