Multi-chip Package Defect Detection via Drive Strength Control
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Solution Overview
Problem
In multi-chip packages, such as memory systems like eMMC and UFS, defects like short-circuits and open channels between bonding wires and memory chips are difficult to detect due to the lack of direct connection to external terminals, hindering effective defect identification.
Innovation Solution
Incorporating a strength control module and interface circuit within the multi-chip package to control drive strengths of output drivers and detect defects by analyzing test data, allowing for accurate identification of short-circuits and open channels through detection data output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bonding wires are used to connect memory controller and memory chips inside the multi-chip package, then electrical connection between components is achieved, but defect detection becomes difficult due to lack of direct connection to external terminals
Solution Approach 1:
The patent introduces an intermediary testing mechanism by controlling different drive strengths of output drivers and analyzing the resulting test data to detect bonding wire defects. The strength control module acts as an intermediary that enables indirect detection of bonding wire issues through controlled signal variations and analysis of detection data, without requiring direct external access to the bonding wires themselves.
Solution Approach 2:
The patent changes the drive strength parameter of output drivers to enable defect detection. By varying the drive strength and analyzing the resulting test data, the system can detect defects in bonding wires and channels that would otherwise be undetectable through normal operation signals.
2Measurement precision
If drive strength of output drivers is controlled to enable defect detection, then measurement precision of bonding wire defects is improved, but device complexity increases due to additional control module
Solution Approach 1:
The strength control module serves multiple functions: it controls drive strength for normal operation, enables defect detection through controlled variations, and facilitates analysis of test data. This multi-functionality reduces the need for separate dedicated testing equipment, thereby limiting the increase in device complexity while improving measurement precision.
3Reliability
If interface circuit analyzes test data to detect short-circuits and open channels, then reliability of defect detection is improved, but manufacturing complexity increases
Solution Approach 1:
The patent merges the defect detection functionality with the existing interface circuit that already handles data transmission between memory controller and memory chips. By combining defect detection operations with normal data operations in the same circuit, the manufacturing process complexity is minimized while achieving reliable defect detection through the analysis of test data.
Data Source
AI summary
Provided are multi-chip packages. A multi-chip package includes a first memory chip and a second memory chip on a printed circuit board; a memory controller electrically connected to the first memory chip and the second memory chip via a first bonding wire and a second bonding wire; and a strength control module configured to control a drive strength of each of a first output driver of the first memory chip and a second output driver of the second memory chip, wherein the memory controller includes an interface circuit configured to receive each of first test data and second test data from the first output driver and the second output driver in which the drive strength is set by the strength control module, and output detection data for detecting whether the first bonding wire and the bonding wire are short-circuited based on the first and second test data.