Method of making electrical connections to a glass-encapsulated semiconductor device
Abstract
Abstract METHOD OF MAKING ELECTRICAL CONNECTIONS TO A GLASSENCAPSULATED SEMICONDUCTOR DEVICE HAVING ALUMINUM CONTACT PADS ON A SILICON DIOXIDE PASSIVATION LAYER. THE METHOD COMPRISES ETCHING AWAY THE GLASS OVER THE CONTACT PADS WITH A SOLUTION THAT ETCHES RAPIDLY BUT DOSE NOT ATTACK THE ALUMINUM AND WHICH CONTAINS A SOLUBLE COMPOUND OF A METAL HAVING AN ELECTRODE POTENTIAL BELOW ALUMINUM IN THE ELECTROCHEMICAL SERIES. THE METAL COMPOUND IS PRESENT IN HIGH ENOUGH CONCENTRATION TO DEPOSITE ON THE ALUMINUM SURFACE FASTER THAN THE ETCHANT CAN REMOVE IT. A THICKER LAYER OF SOLDER-WETTABLE METAL IS THEN ELECTROLESSLY DEPOSITED ON THE FIRST METAL LAYER AND SOLDER BUMPS MAY THEN BE FORMED ON THE SECOND METAL LAYER. THE SECOND METAL LAYER BE COMPOSED OF THE SAME METAL AS THE FIRST.
Inventors
- 👤 Charles Junior Jacob
- 👤 Gerald Wayne Lawton
Bibliographic Details
Claims Analysis
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