Browse Prior Art Database

Void-Free Finger, One-Piece Circuit Screen Mask

IP.com Disclosure Number: IPCOM000036954D
Original Publication Date: 1989-Nov-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Ellerson, JV: AUTHOR [+4]

Abstract

The following describes a circuit screening mask that eliminates printed voids in circuit fingers or circuit line 3 termination ends.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 95% of the total text.

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Void-Free Finger, One-Piece Circuit Screen Mask

The following describes a circuit screening mask that eliminates printed voids in circuit fingers or circuit line 3 termination ends.

The unique feature of this mask is a single cross web 1 that bisects the termination feature 2 (finger or pad). This web must be oriented perpendicular to the direction of travel 4 of the screen tool nozzle or squeegee. The web width 5 must be sufficiently narrow as not to leave an impression or non-printed area under it. In other words, the web width must be less than the distance that the screened material will flow under, therefore providing complete printed material coverage.

The one-piece mask is produced by a double-sided etch process, with the web defined only in the mask side facing the screen nozzle or squeegee 6. Half the mask thickness 7 remains as clearance under the web to allow for the screened material to flow, providing complete print definition of the termination feature.

The web minimizes the flow distance for the screened material from the point of shear, the web leading edge, to the feature edge. This flow distance 8 (position of the web) must be equal to or less than the maximum flow distance of the screened material. This will provide for complete void-free printing of the feature. This also defines the minimum feature size that would require a cross web. The sizes and dimensions will vary depending on the screen material of choice and its associated flow distanc...