Copper Pillar Bump Manufacturing via Ball Placement and Printing

Solution Overview

Problem

Conventional semiconductor packaging processes using chemical plating for copper pillar bumps are time-consuming and costly due to the requirement of expensive equipment, resulting in low efficiency and high production costs.

Innovation Solution

A method involving a ball placement process to form metal bumps on a substrate recess, followed by a printing process to apply solder paste, which includes a reflow process for enhanced bonding, eliminating the need for expensive electroplating equipment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If chemical plating process is used to fabricate copper pillar bumps, then the bumps can be formed with good quality, but the production time is long (60 to 70 minutes) and equipment cost is high

Engineering Contradiction:

Improvebump qualityVSAvoidproduction time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent extracts the copper bump formation step from the chemical plating process and replaces it with a ball placement process. Pre-formed copper balls are directly placed onto the substrate in recesses, eliminating the time-consuming chemical plating steps while maintaining bump quality. This extraction of the core function (forming copper bumps) from the expensive chemical plating process resolves the contradiction between bump quality and production time.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses a disposable stencil for ball placement instead of expensive, reusable chemical plating equipment. The stencil is a simple, low-cost component that can be easily replaced, eliminating the need for costly chemical plating machinery while achieving the same functional result of forming copper bumps.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Manufacturing precision

If chemical plating process is used to fabricate copper pillar bumps, then the bumps can be formed with good quality, but the equipment cost is relatively expensive

Engineering Contradiction:

Improvebump qualityVSAvoidequipment cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent extracts the copper bump formation step from the chemical plating process and replaces it with a ball placement process. Pre-formed copper balls are directly placed onto the substrate in recesses, eliminating the time-consuming chemical plating steps while maintaining bump quality. This extraction of the core function (forming copper bumps) from the expensive chemical plating process resolves the contradiction between bump quality and production time.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses a disposable stencil for ball placement instead of expensive, reusable chemical plating equipment. The stencil is a simple, low-cost component that can be easily replaced, eliminating the need for costly chemical plating machinery while achieving the same functional result of forming copper bumps.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Manufacturing precision

If chemical plating process is used to fabricate copper pillar bumps, then the bumps can be formed, but the production efficiency is low due to long process time

Engineering Contradiction:

Improvebump formationVSAvoidproduction efficiency

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent prepares copper balls in advance and places them directly onto the substrate during the manufacturing process. This preliminary preparation of copper balls eliminates the need for time-consuming chemical plating steps during production, significantly improving production efficiency while maintaining bump formation quality.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent skips the lengthy chemical plating process (60-70 minutes) and directly places pre-formed copper balls onto the substrate. This skipping of the time-consuming plating step rushes through the bump formation process, dramatically improving production efficiency while achieving the same functional result.

Inventive Principle:

Principle #21Skipping (Rushing through)

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

This method reduces production time and costs while maintaining efficiency, offering a simpler and more cost-effective alternative to conventional chemical plating processes for manufacturing metal bump devices.

Implementation Method 1

bonding the metal bump to the recess through the first opening using the flux

Methodology Applied

Scientific EffectChemical adhesion: Adhesive

Implementation Method 2

performing a reflow process on the solder paste

Methodology Applied

Scientific EffectReflow heating: Heating

Data Source

PatentUS10312208B2Copper pillar bump structure and manufacturing method therefor

Publication Date: 2019.06.04 SEMICON MFG INT (SHANGHAI) CORP

AI summary

A method for manufacturing a metal bump device includes providing a substrate structure including a substrate and a metal layer having a recess on the substrate, forming a metal bump on the recess of the metal layer using a ball placement process, and forming a solder paste on the metal bump using a printing process. The manufacturing time is shorter, the manufacturing efficiency is higher, and the manufacturing cost is lower than conventional manufacturing methods.