Laser-Bonded Probe Contact With Low Light Reflective Film

Solution Overview

Problem

In the electrical testing of semiconductor devices, the close proximity of pad electrodes on integrated circuits leads to a demand for fine-pitch contacts, which results in displacement of adjacent contacts due to the heat from laser beams used for bonding, causing inefficiencies and inaccuracies in testing.

Innovation Solution

A contact design featuring a first area for bonding, a second area capable of elastic deformation, and a low light reflective film with lower reflectance than the first area, which absorbs heat energy from the laser beam, preventing displacement of adjacent contacts during bonding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If contacts are arranged in fine pitch to correspond to closely spaced pad electrodes, then test efficiency is improved by enabling simultaneous testing of multiple integrated circuits, but displacement of adjacent contacts occurs due to heat from laser beam bonding

Engineering Contradiction:

Improvetest efficiencyVSAvoidcontact positioning accuracy

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The contact structure employs different material compositions or microstructural characteristics in different regions: the first area (bonding area) has properties optimized for laser beam absorption and bonding, while the second area (extending area) has properties that resist thermal deformation. This local differentiation allows the bonding region to efficiently absorb laser energy for solder melting while the extending area maintains structural stability and resists displacement from thermal effects.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention changes physical parameters of the contact structure, specifically the material composition or microstructure, to create regions with different thermal properties. The first area is designed with parameters that favor laser beam absorption and heat generation for bonding, while the second area has parameters that provide thermal resistance and dimensional stability, thereby preventing displacement during the bonding process.

Inventive Principle:

Principle #35Parameter changes

2Strength

If laser beam heat source is used to bond contacts to the board, then bonding strength is improved, but adjacent contacts suffer from displacement due to heat exposure

Engineering Contradiction:

Improvebonding strengthVSAvoidcontact positioning accuracy

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The contact structure employs different material compositions or microstructural characteristics in different regions: the first area (bonding area) has properties optimized for laser beam absorption and bonding, while the second area (extending area) has properties that resist thermal deformation. This local differentiation allows the bonding region to efficiently absorb laser energy for solder melting while the extending area maintains structural stability and resists displacement from thermal effects.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention converts the harmful thermal effect of the laser beam into a beneficial localized heating effect. By designing the first area with specific material properties that favor laser beam absorption, the heat that would otherwise cause displacement is concentrated precisely where needed - at the bonding interface - enabling strong bonding while the second area remains relatively cool and dimensionally stable.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 low light reflective film effectively absorbs heat energy, allowing for bonding with lower heat influence on adjacent contacts, reducing displacement and maintaining accurate probe tip positioning for efficient electrical testing.

Implementation Method 1

a low light reflective film having lower light reflectance than that of the first area and formed on a surface of at least a part of the bonding part of the first area to the board

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentUS8063651B2Contact for electrical test of electronic devices, probe assembly and method for manufacturing the same

Publication Date: 2011.11.22 NIHON MICRONICS KK

AI summary

A contact for an electrical test comprises a first area to be bonded to a board, a second area extending in the right-left direction from the lower end portion of the first area, a third area projecting downward from the tip end portion of the second area, and a low light reflective film having lower light reflectance than that of the first area. The third area has a probe tip to be contacted an electrode of an electronic device. The low light reflective film is formed on a surface of at least the bonding part of the first area to the board and its proximity.