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Method and System for Providing Asymmetric Bond Pads for Controlling Solder Ball Standoffs

IP.com Disclosure Number: IPCOM000235020D
Publication Date: 2014-Feb-24
Document File: 2 page(s) / 86K

Publishing Venue

The IP.com Prior Art Database

Abstract

A method and system is disclosed for providing asymmetric bond pads for controlling solder ball standoffs.

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Method and System for Providing Asymmetric Bond Pads for Controlling Solder Ball Standoffs

Disclosed is a method and system for providing asymmetric bond pads for controlling solder ball standoffs. The method and system utilizes the asymmetric bond pads for enhancing proper collapse of the solder balls on standoffs. The asymmetric bond pads are integrated with standoffs made of at least one of a polymer and a nickel core for enhancing the support for solder ball collapse. The standoffs are vertically aligned between optical fibers and silicon waveguides integrated on silicon photonic chips for providing accurate and high coupling efficiency.

As shown in the Fig. 1, asymmetric bond pads used for chip joining are arranged vertically opposite to each other.

Figure 1

As illustrated in Fig. 1, the asymmetric bond pads are attached to packlite chips at one side and to glass interposers on the other side, which leaves space for arranging the

solder balls. Subsequently, when the chip joining process is initiated, the solder balls spread onto a wide bond pad that is attached to the glass interposer. Further, both the packlite chips and glass interposers are supported by spacers preventing the asymmetric bond pads from contacting each other while the solder balls are being melted.

As shown in the Fig. 2, different orientations of the asymmetric bond pads are observed

when the solder balls melt. Further, as illustrated, long axis asymmetric bond pads have alternate x and y...