Semiconductor Inspection Using Segmented Dark and Light Testing
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Solution Overview
Problem
Conventional methods for inspecting semiconductor devices, such as LSIs, do not account for light exposure during practical use, leading to potential deterioration and defective products in applications like LCD panels, where LSIs may be exposed to backlighting, causing qualified products to malfunction.
Innovation Solution
A dual-testing method where semiconductor devices are initially inspected in a dark environment to identify non-defective units, followed by a second test under controlled light exposure using white LEDs with specific chromatic coordinates, simulating the backlight conditions, to identify any light-induced defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional probe test is carried out in a dark box to inspect semiconductor devices, then the inspection can be completed without light interference, but light-induced defects cannot be detected and defective products may be shipped
Solution Approach 1:
The inspection process is divided into two separate tests: a first test in dark conditions to identify initial defects, and a second test with light application to detect light-induced defects. This segmentation allows each test to focus on specific defect types without interference from the other condition, thereby improving both reliability and measurement precision.
Solution Approach 2:
The first test in dark conditions is performed before the second test with light application. This preliminary action identifies devices with baseline defects, allowing the subsequent light-exposure test to focus specifically on detecting light-induced defects, thereby improving the overall detection accuracy and reliability.
2Productivity
If only a single dark-condition test is performed, then the inspection process is simple and fast, but light-induced defects remain undetected
Solution Approach 1:
The inspection process is divided into two separate tests: a first test in dark conditions to identify initial defects, and a second test with light application to detect light-induced defects. This segmentation allows each test to focus on specific defect types without interference from the other condition, thereby improving both reliability and measurement precision.
Solution Approach 2:
The inspection employs periodic action by performing two distinct tests in sequence: first under dark conditions, then under light conditions. This periodic approach ensures comprehensive defect detection while maintaining systematic process control, balancing productivity with improved reliability.
3Measurement precision
If a dual-test method with light exposure is implemented, then light-induced defects can be detected, but the inspection process becomes more complex and time-consuming
Solution Approach 1:
The inspection process is divided into two separate tests: a first test in dark conditions to identify initial defects, and a second test with light application to detect light-induced defects. This segmentation allows each test to focus on specific defect types without interference from the other condition, thereby improving both reliability and measurement precision.
Solution Approach 2:
The first test in dark conditions is performed before the second test with light application. This preliminary action identifies devices with baseline defects, allowing the subsequent light-exposure test to focus specifically on detecting light-induced defects, thereby improving the overall detection accuracy and reliability.
4Measurement precision
If a dual-test method with light exposure is implemented, then light-induced defects can be detected, but the inspection time increases
Solution Approach 1:
The inspection process is divided into two separate tests: a first test in dark conditions to identify initial defects, and a second test with light application to detect light-induced defects. This segmentation allows each test to focus on specific defect types without interference from the other condition, thereby improving both reliability and measurement precision.
Solution Approach 2:
The inspection employs periodic action by performing two distinct tests in sequence: first under dark conditions, then under light conditions. This periodic approach ensures comprehensive defect detection while maintaining systematic process control, balancing productivity with improved reliability.
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 approach reduces the incidence of defective products by identifying light-induced changes in semiconductor characteristics, ensuring only robust devices are classified as non-defective and shipped, thereby improving product reliability.
Implementation Method 1
using white LEDs with specific chromatic coordinates, simulating the backlight conditions
Data Source
AI summary
A method for inspecting a semiconductor device includes carrying out a first test for inspecting characteristics of semiconductor devices under a shielded (dark) condition to discriminate non-defective devices; and carrying out a second test on the semiconductor devices which have passed the first test as non-defective devices, for inspecting characteristics of the semiconductor devices. The second test is carried out while a predetermined color of light is applied to the semiconductor devices.