Browse Prior Art Database

Controlling Volume And Location of Ink for Through Hole/Via Screening

IP.com Disclosure Number: IPCOM000100469D
Original Publication Date: 1990-Apr-01
Included in the Prior Art Database: 2005-Mar-15
Document File: 1 page(s) / 28K

Publishing Venue

IBM

Related People

Logan, JB: AUTHOR [+2]

Abstract

Disclosed is a method of volume and location control for the ink in through hole/via screening by using a specially designed screen.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Controlling Volume And Location of Ink for Through Hole/Via Screening

       Disclosed is a method of volume and location control for
the ink in through hole/via screening by using a specially designed
screen.

      As the substrate thickness and the hole diameters increase, the
volume of ink and location of ink flow in through hole screening
becomes more critical.  To achieve this, an adequate quantity of ink
needs to be available and the ink should be located directly over the
walls of the holes.  The ink can then be drawn down the surface area
of the hole and coating will occur.

      A special screen was developed to control the volume of ink and
the location.  See the figure.  The screen is built up on the top
side with a thick emulsion layer 1.  (Other materials may be used.)
Then the over-sized hole/image 2 is exposed.  The bottom of the
screen is coated with emulsion 3, and a donut-shaped image (for round
holes) 4 is made. The top layer regulates the volume of ink that is
available for coating and the bottom image controls the location of
the flow of the ink.