Powered Functional Device Testing for BGA Connection Reliability
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Solution Overview
Problem
Existing reliability testing methods for semiconductor devices, such as board level reliability (BLR) and 2nd level solder joint reliability tests (SJRT), are costly and time-consuming due to the use of special test devices that cannot be powered during testing, and they fail to accurately identify specific connection failures in ball grid array (BGA) devices.
Innovation Solution
A method involving temporary mounting of production devices on a test board with non-permanent connections, allowing environmental testing while powered, and using the production device itself to test structural and electrical integrity, including connections between external connectors and internal vias.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If special test daisy chain devices are used for reliability testing, then solder joint reliability can be tested, but the testing process becomes costly and time-consuming
Solution Approach 1:
The patent uses a copy of the actual device (a daisy chain device with identical external connector configuration) to perform reliability testing. This copy replicates the external form and connector arrangement of the production device, allowing standard testing procedures to be applied without requiring modification of the actual production device. The copying principle resolves the contradiction by enabling reliable testing through a surrogate that mimics the target device's external characteristics.
Solution Approach 2:
The patent introduces an intermediary testing system consisting of a test board with multiple connection pads and a controller that coordinates testing across multiple devices. This intermediary system automates the testing process, allowing simultaneous testing of multiple solder joints across several daisy chain devices. The mediator enables efficient, automated reliability testing that reduces both time and cost while maintaining comprehensive coverage of solder joint integrity.
2Measurement precision
If daisy chain devices are used for testing, then solder joint connections can be evaluated, but functional aspects of the production device cannot be tested
Solution Approach 1:
The patent segments the testing function into two distinct parts: (1) structural/connection integrity testing performed by the daisy chain devices and test board, and (2) functional performance testing performed separately on production devices. This segmentation allows each testing type to be optimized independently - the daisy chain configuration provides precise connection failure identification, while production devices can be separately evaluated for functional performance. The segmentation resolves the contradiction by allowing both testing objectives to be achieved through separate, specialized testing procedures.
3Reliability
If special test devices are manufactured, then reliability testing can be performed, but significant time and cost are incurred
Solution Approach 1:
The patent designs the daisy chain devices with a universal external connector configuration that matches standard production devices, allowing the same device architecture to serve both production and testing purposes. The test board is designed with a universal interface that can accommodate multiple daisy chain devices simultaneously. This universality reduces manufacturing complexity by using standard components and configurations rather than requiring custom, specialized hardware for each testing application.
Solution Approach 2:
The patent employs inexpensive daisy chain devices that are specifically designed for testing purposes and can be easily manufactured. These test devices are treated as consumables that can be produced in large quantities at low cost, replacing the need for expensive, complex specialized testing equipment. The cheap, disposable nature of these test devices resolves the contradiction by providing reliable testing capability without significant manufacturing investment.
4Reliability
If traditional BLR or SJRT methods are used, then solder joint reliability can be assessed, but specific connection failures in BGA devices cannot be accurately identified
Solution Approach 1:
The patent uses daisy chain devices that are external copies of production devices with identical connector arrangements. These copies maintain the same external geometry and connector positions, allowing precise mapping of test results back to specific locations on the production device. The copying principle enables accurate identification of connection failure locations by preserving the spatial relationship between connectors and internal components.
Solution Approach 2:
The patent implements a feedback mechanism where the controller monitors electrical continuity through the daisy chain configuration and provides real-time information about connection integrity. The test board measures resistance or continuity between connection pads, and this feedback data is used to identify which specific solder joints or connectors have failed. The feedback system resolves the contradiction by providing both overall reliability assessment and precise localization of connection failures through electrical measurement and data analysis.
Data Source
AI summary
Devices and methods are provided for using production devices during environmental testing. The structural and electrical integrity of external electrical connectors of a production device are determined, for instance, for board level reliability or second level solder joint reliability tests. Operational characteristics or internal connections of the production device can be monitored during testing.