Transparent Position Checking Member for Probe Card Alignment
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Solution Overview
Problem
Conventional inspection systems for semiconductor devices face challenges in ensuring contact accuracy between probe cards and wafers due to misalignment caused by factors like driving system accuracy and temperature changes, leading to the consumption of alignment substrates during probe mark inspection.
Innovation Solution
A method and mechanism that utilize a transparent position checking member simulating the probe card with alignment marks, coupled to a mounting part, and position checking cameras to detect horizontal deviations between marks on the alignment substrate and the position checking member, ensuring contact accuracy without consuming the alignment substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If probe mark inspection (PMI) is performed by actually contacting probes with the reference wafer, then contact accuracy can be assured, but the alignment substrate is consumed and probe card may be damaged
Solution Approach 1:
The patent uses a position checking member as a transparent copy or simulation of the probe card, which contains mark positions corresponding to the actual probe positions. This copy allows non-contact verification of alignment accuracy by comparing the position of marks on the reference wafer with the position of marks on the position checking member, thereby assuring contact accuracy without consuming the alignment substrate or risking probe card damage
Solution Approach 2:
The position checking member serves as an intermediary between the reference wafer and the actual probe card. Instead of directly contacting the probe card with the reference wafer for inspection, the transparent position checking member is used as a mediator that can be optically inspected without physical contact, thus preventing both substrate consumption and probe damage while still verifying alignment accuracy
2Ease of operation
If alignment is performed using separate alignment area and contact area, then alignment process can be completed, but misalignment occurs due to driving system accuracy and temperature changes
Solution Approach 1:
The patent merges the verification of alignment accuracy into the alignment process itself by using the position checking member that remains in the contact area. The mark positions on this member serve as permanent reference points that can be repeatedly checked without moving between separate alignment and contact areas, thereby maintaining both ease of operation and high alignment precision
Solution Approach 2:
The position checking member is prepared in advance with mark positions that correspond to the probe card positions. This preliminary setup allows for immediate verification of alignment accuracy once the reference wafer is positioned, eliminating the need for separate alignment area operations and ensuring precision is maintained in the contact area
3Measurement precision
If probe mark inspection is performed to assure contact between probes and electrode pads, then contact accuracy is verified, but operational costs increase and probe card may be damaged
Solution Approach 1:
The transparent position checking member serves as a reusable copy of the probe card that can be optically inspected multiple times without consumption. This copy allows precise measurement of contact accuracy through non-contact optical methods, eliminating the need for expensive and potentially damaging physical probe contact inspections
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 allows for non-contact assurance of contact accuracy between the substrate and probe card, reducing operational costs and preventing damage to the probe card, while maintaining high-precision positioning without the need for probe mark inspection.
Implementation Method 1
detecting horizontal deviations between the first marks and the second marks by capturing images of the first marks and the second marks with position checking cameras provided above the position checking member at positions respectively corresponding to the second marks to capture the images from a top down angle
Data Source
AI summary
In a method for contact accuracy assurance in an inspection apparatus, an alignment substrate having first marks is placed and aligned on a stage, and a position checking member, which is a transparent body simulating a probe card and has second marks at positions corresponding to the first marks, is coupled to a mounting part where the probe card is to be coupled. Further, the alignment substrate is placed in a contact area directly below the position checking member. Horizontal deviations between the first and the second marks are detected by capturing images of the first and the second marks with position checking cameras provided above the position checking member at positions respectively corresponding to the second marks to capture the images from a top down angle. The contact accuracy between the substrate and probes of the probe card is assured when the deviations are within an allowable range.