Test Fixture for Stacked Integrated Circuit Assemblies

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Testing stacked integrated circuit packages is challenging due to difficulty in fault isolation and parasitic effects from long leads, which limit testing speed and effectiveness.

Innovation Solution

A method and apparatus for testing stacked devices by using a test fixture with pick and place arms to electrically couple primary and secondary circuit assemblies, allowing simultaneous testing in a nearly finished configuration, reducing the need for long test leads and enhancing testing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If all integrated circuit packages and/or dice must be electrically coupled to test any single die, then testing can be performed, but fault isolation becomes difficult

Engineering Contradiction:

Improvefault isolation capabilityVSAvoidelectrical coupling arrangement

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the electrical coupling arrangement by introducing a test fixture that independently couples to each die in the stacked package. Instead of requiring all dies to be coupled together, the test fixture creates separate test paths to each die, enabling independent testing and fault isolation without compromising the complexity of the overall electrical coupling arrangement.

Inventive Principle:

Principle #1Segmentation

2Productivity

If long leads are used for testing, then electrical coupling is achieved, but test fixture parasitic effects limit testing speed and effectiveness

Engineering Contradiction:

Improvetesting speedVSAvoidtest fixture parasitic effects

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the test leads from the traditional long external connections and relocates them to the test fixture interface. By taking out the long leads and replacing them with direct coupling through the test fixture, the patent eliminates the parasitic effects associated with long leads while maintaining electrical coupling capability, thereby improving testing speed and effectiveness.

Inventive Principle:

Principle #2Taking out (Extraction)

3Reliability

If stacked die packages are tested in nearly finished configuration, then testing effectiveness is improved, but test fixture design complexity increases

Engineering Contradiction:

Improvetesting effectivenessVSAvoidtest fixture design

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies universality by designing a test fixture that can accommodate multiple die configurations and stacking arrangements. The test fixture is designed with universal coupling mechanisms that work across different stacked die package types, enabling effective testing in nearly finished configuration without requiring entirely new fixture designs for each variant, thus managing the complexity increase.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS9575117B2Testing stacked devices

Publication Date: 2017.02.21 ADVANTEST CORP

AI summary

Testing stacked devices. In accordance with a first method embodiment, a primary circuit assembly is accessed from a first circuit assembly carrier. The primary circuit assembly is placed into a test fixture. A secondary circuit assembly is accessed from a second circuit assembly carrier. The secondary circuit assembly is placed into the test fixture on top of the primary circuit assembly. The primary circuit assembly is tested in conjunction with said secondary circuit assembly while coupled together.