Browse Prior Art Database

Mini-Screener

IP.com Disclosure Number: IPCOM000108803D
Original Publication Date: 1992-Jun-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 60K

Publishing Venue

IBM

Related People

Isaacs, PD: AUTHOR [+4]

Abstract

This mini-screener is used to screen solder paste onto small printed circuit boards or components through a stencil for the purpose of soldering to something else.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 78% of the total text.

Mini-Screener

       This mini-screener is used to screen solder paste onto
small printed circuit boards or components through a stencil for the
purpose of soldering to something else.

      The mini-screener comprises the following features:
1. Stencil and frame are used for screening paste on components or
small cards.
2. Component or card.
3. Registration platen is used to center the module or card as well
as control relative height of the stencil to the object being
screened.  Different platens are used for different module or card
applications.
4. Vacuum chuck is used to hold down module or card to prevent any
movement.
5. Z Stage is used to adjust relative height of the component to the
platen to obtain proper snap-off for paste screening.
6. Theta stage is used to rotate the component or card for alignment
to the stencil.
7. X,Y stage is used to adjust alignment of module or card to the
stencil.
8. Z stage is used for vertical adjustment and snap-off.

      Once the solder stencil is aligned with the object, the solder
paste is applied to the stencil and pulled across the stencil with a
squeegee.  The stencil is lifted up, and the object is then removed.
Another one is then placed, and the process is repeated (see the
figure).

      We needed to be able to screen the solder paste on to the back
side of a module.  The current screeners did not allow independent
height adjustments between a platen and module relative to the solder
paste stencil. ...