Texturing of a die pad surface for enhancing bonding strength in the surface attachment
First Claim
1. A method of bonding a semiconductor die to an attachment pad therefor comprising the steps of:
- (a) directing a modulated laser output beam onto a plurality of surface regions of a surface portion of said attachment pad, so as to texture said surface portion of said attachment pad with a plurality of indentations; and
(b) attaching said semiconductor chip to said attachment pad, by an adhesive, which contacts each of a surface portion of said semiconductor chip directly facing said surface portion of said attachment pad and directly facing indentations that have been formed in said surface portion of said attachment pad in step (a).
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Accused Products
Abstract
Laser beam or pulsed output is provided for enhancing the bonding strength between surfaces that are secured together, such as by lamination process or an adhesive, by texturing with a plurality of indentations formed in at least one of the surfaces to be bonded. As an example of this texturing, a fiber gain medium texturing system having a modulated pump or seed semiconductor laser source may be employed for forming a plurality of indentations in the surface of a die attachment pad of a semiconductor die or IC chip carrier. The indentations may be in the form of dimples or grooves. The indentations enhance the bonding strength formed between the chip and the die attachment pad using a die attaching adhesive. Also, the indentations in the die attachment pad provide a way for containment of rapidly expanding gases that formed in the chip carrier package when the package is subjected to high temperatures such as during a solder reflow operation.
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Citations
14 Claims
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1. A method of bonding a semiconductor die to an attachment pad therefor comprising the steps of:
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(a) directing a modulated laser output beam onto a plurality of surface regions of a surface portion of said attachment pad, so as to texture said surface portion of said attachment pad with a plurality of indentations; and
(b) attaching said semiconductor chip to said attachment pad, by an adhesive, which contacts each of a surface portion of said semiconductor chip directly facing said surface portion of said attachment pad and directly facing indentations that have been formed in said surface portion of said attachment pad in step (a). - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of joining a first workpiece to a second workpiece comprising the steps of:
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(a) directing a modulated laser output beam onto a plurality of surface regions of a bonding surface portion of said first workpiece, so as to texture said bonding surface portion of said first workpiece with a plurality of indentations;
(b) positioning said second workpiece so that a bonding surface portion thereof is directly facing indentations formed in said bonding surface portion of said first workpiece in step (a); and
(c) attaching said bonding surface portion of said second workpiece to said bonding surface portion of said first workpiece attachment pad, by an adhesive which bonds said bonding surface portion of said second workpiece with said indentations formed in said bonding surface portion of said first workpiece and directly facing said bonding surface portion of said second workpiece. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
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Specification