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US 5,583,285 AGranted
Method for detecting a coating material on a substrate
AssigneeLucent Technologies Inc.
InventorsMark H. Hahn, Mary L. Patterson
Life of this patent
Estimating the term…
Abstract
A method for detecting the presence of a coating material, particularly an organic solderability preservative, such as imidazole, on a copper substrate includes placing a test droplet on the surface of the substrate, forming an image of the droplet and measuring the contact angle between the wall of the droplet and the surface of the substrate.
Claims6
A method for monitoring a process for coating a copper substrate with a layer of organic solderability preservative, comprising:
- a) providing a copper sheet;
- b) etching a surface of said copper sheet;
- c) coating said copper surface with an organic solderability preservative;
- d) placing a droplet of test liquid on said coated surface within 10 minutes after coating said copper substrate;
- e) obtaining an image of the droplet;
- f) measuring the contact angle defined by a wall of the droplet and the coated surface within about 30 seconds after placing said droplet on said coated substrate;
- and
- g) comparing the measured value of the contact angle with a predetermined standard comprising known values of contact angles.
5 more elements
Dependencies are inferred from the claim text.