Semiconductor Die Pad Resin Adhesion via Bonding Agent Dimples

Solution Overview

Problem

Conventional semiconductor devices experience resin peeling and cracking due to uneven adhesion between the die pad and resin, primarily because top-side dimples on the die pad are filled with bonding agent, leading to stress and reduced reliability.

Innovation Solution

Forming dimples in the bonding agent on the margin of the die pad where the semiconductor chip is mounted, which enhances the anchoring effect and improves adhesion between the resin and the die pad, preventing resin cracking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dimples are formed on the top surface of the die pad to improve adhesion, then adhesion should be improved, but the dimples are filled with bonding agent and fail to provide the intended adhesion benefit

Engineering Contradiction:

Improveadhesion between resin and die padVSAvoiddimple filling with bonding agent

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

Instead of forming dimples on the top surface of the die pad (which gets filled with bonding agent), the invention inverts the approach by forming dimples on the bottom surface of the die pad. This ensures the dimples remain exposed and can effectively anchor the resin, solving the filling problem while maintaining the adhesion improvement function.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The invention applies local quality by creating dimples specifically on the bottom surface of the die pad in the margin area, rather than uniformly across the entire surface. This localized treatment provides enhanced adhesion precisely where the resin needs anchoring, without affecting other areas.

Inventive Principle:

Principle #3Local quality

2Reliability

If bonding agent is applied to the margin of the die pad, then adhesion coverage is improved, but stress concentration occurs leading to resin cracking

Engineering Contradiction:

Improveadhesion coverageVSAvoidresin cracking

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention applies local quality by creating dimples specifically on the bottom surface of the die pad in the margin area, rather than uniformly across the entire surface. This localized treatment provides enhanced adhesion precisely where the resin needs anchoring, without affecting other areas.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

Instead of forming dimples on the top surface of the die pad (which gets filled with bonding agent), the invention inverts the approach by forming dimples on the bottom surface of the die pad. This ensures the dimples remain exposed and can effectively anchor the resin, solving the filling problem while maintaining the adhesion improvement function.

Inventive Principle:

Principle #13The other way round (Inversion)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively prevents resin peeling and cracking by ensuring strong adhesion between the resin and the die pad, significantly improving the reliability of the semiconductor device without adding complexity to the manufacturing process.

Implementation Method 1

Forming dimples in the bonding agent on the margin of the die pad where the semiconductor chip is mounted, which enhances the anchoring effect and improves adhesion between the resin and the die pad

Methodology Applied

Scientific EffectAnchoring effect: Mechanical Fastener

Data Source

PatentUS7582974B2Semiconductor device and method of manufacturing same

Publication Date: 2009.09.01 RENESAS ELECTRONICS CORP

AI summary

A semiconductor device that improves adhesion between a resin and a die pad and prevents cracking of the resin includes: a semiconductor chip; a die pad on which the semiconductor chip is mounted; a bonding agent for bonding the semiconductor chip to the die pad; a plurality of inner leads provided at the outer periphery of the die pad; outer leads extending from the inner leads; bonding wires connecting the inner leads to the semiconductor chip mounted on the die pad; and a resin for sealing the inner leads, the die pad, the semiconductor chip, the bonding agent and the bonding wires. The bonding agent is further disposed in all or part of a margin of the die pad at a peripheral portion where the semiconductor chip is mounted, and a plurality of dimples are formed in the surface of the bonding agent in the die pad margin.