Wire Bonding Apparatus Capillary Scrubbing Mechanism

Solution Overview

Problem

Conventional wire bonding methods face issues with wire fall-out and bending, leading to defective ball formation and reduced bonding strength, as they require precise adjustment of capillary pressing force and are prone to S-shaped wire deformation and contact between adjacent wires.

Innovation Solution

A wire bonding apparatus with a capillary, first clamper, and second clamper, controlled by a unit that cuts the wire by moving upward while the first clamper is closed and extends the wire by moving the capillary and first clamper upward with the second clamper closed, incorporating a scrubbing operation to facilitate cutting and prevent fall-out.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the wire is cut by holding it with the clamper and moving it upward after bonding to the lead, then the wire can be cut at the end portion, but the wire may bend into an S shape and cause defective ball formation

Engineering Contradiction:

Improvewire cutting easeVSAvoidwire shape precision

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The capillary performs a scrubbing operation during bonding to pre-crush the wire at the bonding end, creating a smaller cross-sectional area that facilitates easier cutting while preventing S-shaped bending during the subsequent upward movement

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The capillary acts as an intermediary tool that not only bonds the wire but also pre-processes it through scrubbing to create a weakened section, enabling controlled cutting without affecting the overall wire shape

Inventive Principle:

Principle #24Intermediary (Mediator)

2Strength

If the pressing force of the capillary is increased to ensure bonding strength, then the bonding strength improves, but the wire may be cut during bonding and fall out from the capillary

Engineering Contradiction:

Improvebonding strengthVSAvoidwire retention reliability

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The capillary performs a scrubbing operation during bonding to pre-crush the wire at the bonding end, creating a smaller cross-sectional area that facilitates easier cutting while preventing S-shaped bending during the subsequent upward movement

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system changes the physical state of the wire at the bonding end through scrubbing, creating a localized difference in cross-sectional area that allows for controlled cutting without affecting wire retention in the capillary

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the pressing force of the capillary is decreased to prevent wire cutting during bonding, then wire fall-out is prevented, but the bonding strength may be insufficient

Engineering Contradiction:

Improvewire retention reliabilityVSAvoidbonding strength

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The system changes the physical state of the wire at the bonding end through scrubbing, creating a localized difference in cross-sectional area that allows for controlled cutting without affecting wire retention in the capillary

Inventive Principle:

Principle #35Parameter changes

4Ease of manufacture

If the capillary and clamper are moved transversely to align with the bonding end before cutting, then the wire can be cut more effectively, but the process complexity increases

Engineering Contradiction:

Improvewire cutting effectivenessVSAvoidbonding process complexity

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The capillary performs a scrubbing operation during bonding to pre-crush the wire at the bonding end, creating a smaller cross-sectional area that facilitates easier cutting without requiring transverse movement

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The scrubbing operation is performed continuously during the bonding process, eliminating the need for separate transverse movement and alignment steps, thereby maintaining process simplicity

Inventive Principle:

Principle #20Continuity of useful action

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

Effectively suppresses wire fall-out and bending, ensuring stable bonding by cutting the wire before it can fall out and reducing the need for precise force adjustments, while enhancing bonding strength through the scrubbing operation.

Implementation Method 1

a method of causing a capillary to perform a scrubbing operation when bonding while pressing the wire against a bonding surface using the capillary

Methodology Applied

Scientific EffectUltrasonic vibration: Ultrasonic Vibration

Data Source

PatentUS8191759B2Wire bonding apparatus and wire bonding method

Publication Date: 2012.06.05 YAMAHA ROBOTICS CO LTD

AI summary

Provided is a wire bonding apparatus including: a wire cutting unit configured to cut a wire by bonding the wire using a capillary and then moving the capillary and a first clamper upward while the first clamper remains closed; and a wire extending unit configured to extend a tail wire from a tip end of the capillary by moving the capillary upward and then moving the capillary and the first clamper upward in a state in which the first clamper is opened and a second clamper is closed. The wire bonding apparatus having such a structure effectively prevents the wire from falling out and bending.