Browse Prior Art Database

Method for a trace defined solder-mask opening

IP.com Disclosure Number: IPCOM000008387D
Publication Date: 2002-Jun-11
Document File: 3 page(s) / 95K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for trace defined solder-mask opening. Benefits include improved reliability.

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Method for a trace defined solder-mask opening

Disclosed is a method for trace defined solder-mask opening. Benefits include improved  reliability.

Background

              Higher density routing and increasing I/O requirements can be achieved through direct interconnection between the die and a terminated trace (see Figure 1). Solder mask defined bump-pad opening is no longer required because substrate bump pads no longer exist (see Figure 2).

Description

      The disclosed method utilizes a solder-mask opening to reveal the substrate trace termination end for interconnection to a flip-chip die in a substrate bump padless technology or flip-chip direction interconnection to trace technology.

      The key elements include:

·        Padless technology or direction trace interconnection does not require bump pads unlike the conventional interconnect between substrates to die. The interconnection is between the die and terminated traces on the substrates (see Figure 3).

·        This direction trace interconnection technology does not require solder resist material underneath the die because a nonconductive epoxy underfill material is applied between the die and the substrate. This epoxy application is an existing process of record (POR).

      A solder-resist opening exists underneath the die in a flip-chip package (see Figure 4). Bump pads no longer occur in the padless technology. Solder-resist define pads are not required. Interconnection is between the solder bump and the exposed trace termination.

Advantages

              The dis...