Wiring Substrate with Mixed NSMD and SMD Connection Pads

Solution Overview

Problem

Conventional wiring substrates face challenges in accurately positioning semiconductor chips with mixed peripheral and area array bumps due to structural limitations, which hinder the formation of power supply lines in a flat, integral body, affecting electric characteristics.

Innovation Solution

A wiring substrate design featuring connection pads in a non-solder mask defined (NSMD) structure for the peripheral portion and solder mask defined (SMD) structure for the center portion, with positioning marks in the NSMD structure, allowing for narrow pad pitches and flat plate formation of power supply lines.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If connection pads are formed in NSMD structure for all portions, then positioning precision is improved, but power supply lines cannot be formed in a flat integral body

Engineering Contradiction:

Improvepositioning precisionVSAvoidflat plate shape of power supply lines

Core Design Contradiction:

Measurement precisionVSShape

Solution Approach 1:

The wiring substrate is divided into two regions: a first region with NSMD structure for connection pads requiring high positioning precision, and a second region with SMD structure for power supply lines requiring flat plate formation. This spatial segmentation allows each region to optimize for its specific functional requirement without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different structures are applied to different locations on the wiring substrate based on local functional requirements. The NSMD structure is used where precise bump positioning is critical, while the SMD structure is used where flat plate power supply line formation is prioritized, achieving local optimization throughout the substrate.

Inventive Principle:

Principle #3Local quality

2Shape

If connection pads are formed in SMD structure, then power supply lines can be formed in a flat integral body, but positioning precision for mixed bump arrangements deteriorates

Engineering Contradiction:

Improveflat plate shape of power supply linesVSAvoidpositioning precision

Core Design Contradiction:

ShapeVSMeasurement precision

Solution Approach 1:

The wiring substrate is divided into two regions: a first region with NSMD structure for connection pads requiring high positioning precision, and a second region with SMD structure for power supply lines requiring flat plate formation. This spatial segmentation allows each region to optimize for its specific functional requirement without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different structures are applied to different locations on the wiring substrate based on local functional requirements. The NSMD structure is used where precise bump positioning is critical, while the SMD structure is used where flat plate power supply line formation is prioritized, achieving local optimization throughout the substrate.

Inventive Principle:

Principle #3Local quality

3Ease of manufacture

If all connection pads use the same structure, then manufacturing process is simplified, but both narrow pad pitches and flat power supply line formation cannot be achieved simultaneously

Engineering Contradiction:

Improvemanufacturing process simplicityVSAvoidpad pitch reduction and power supply line formation

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The wiring substrate is divided into two regions: a first region with NSMD structure for connection pads requiring high positioning precision, and a second region with SMD structure for power supply lines requiring flat plate formation. This spatial segmentation allows each region to optimize for its specific functional requirement without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different structures are applied to different locations on the wiring substrate based on local functional requirements. The NSMD structure is used where precise bump positioning is critical, while the SMD structure is used where flat plate power supply line formation is prioritized, achieving local optimization throughout the substrate.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS8232641B2Wiring substrate and semiconductor device having connection pads formed in non-solder mask defined structure

Publication Date: 2012.07.31 SHINKO ELECTRIC IND CO LTD

AI summary

A wiring substrate includes: a semiconductor chip on which a plurality of bumps are mounted, and a plurality of connection pads which are joined to the bumps mounted on the semiconductor chip in a flip chip method, wherein the connection pads of a peripheral portion of the wiring substrate are formed in a non-solder mask defined structure, and the connection pads of a center portion of the wiring substrate are formed in a solder mask defined structure.