Optical Bonding Head Alignment for Die-to-Wafer Bonding Accuracy
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Solution Overview
Problem
Existing bonding technologies face challenges in achieving accurate alignment and reducing stress-induced breakage during die-to-wafer bonding, particularly due to uneven local stress and large size disparities between wafers and dies, leading to reduced yield and accuracy in semiconductor manufacturing.
Innovation Solution
A bonding system and method that utilizes a first alignment assembly to adjust the bonding head to be parallel to the horizontal plane, determining offset and deviation values to accurately align dies with wafers, reducing stress and improving alignment accuracy through optical path alignment and calibration marks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If die to wafer bonding is performed without alignment adjustment, then bonding process is simple, but alignment accuracy between die and wafer is poor leading to reduced bonding yield
Solution Approach 1:
The alignment assembly performs preliminary alignment detection and adjustment before the actual bonding process. The system detects the position of the die and wafer using optical paths, calculates deviation values, and adjusts their positions in advance to ensure accurate alignment before bonding occurs, thereby improving alignment accuracy without significantly complicating the bonding operation itself
Solution Approach 2:
The alignment assembly acts as an intermediary component between the die/wafer and the bonding head. It includes optical paths, detectors, and adjustment mechanisms that mediate the alignment process by detecting positions and controlling the movement of die and wafer to achieve precise alignment before the bonding action takes place
2Reliability
If bonding head is not adjusted to be parallel to horizontal plane, then bonding process is faster, but die breakage probability increases due to uneven local stress
Solution Approach 1:
The alignment assembly performs preliminary detection of the bonding head's parallelism to the horizontal plane using optical paths before bonding. It calculates offset values and adjusts the bonding head's position in advance to ensure it is parallel to the horizontal plane, thereby eliminating uneven local stress and preventing die breakage before the bonding process begins
Solution Approach 2:
The alignment assembly provides feedback control by detecting the bonding head's position and orientation using optical paths, comparing it to the ideal parallel state, and automatically adjusting the bonding head's position based on the detected deviations. This closed-loop feedback ensures the bonding head is properly aligned before each bonding operation, preventing die breakage while maintaining process efficiency
Data Source
Figure 1~2B
Figure 3A~3B
Figure 3C~4A
AI summary
Embodiments of the present disclosure disclose a bonding system and a bonding method. The bonding system includes a bonding assembly, a first alignment assembly, and a second alignment assembly. The bonding assembly includes a bonding head and a first optical path penetrating the bonding head. The first alignment assembly is configured to determine an offset of the picking surface with respect to a horizontal plane when the bonding head is located at a first position. The bonding assembly is further configured to drive, according to the offset, the bonding head to move to a second position parallel to the horizontal plane. The first alignment assembly is further configured to transmit a detection optical signal to a first end via a second end of the first optical path when the bonding head is located at the second position. The first alignment assembly is further configured to receive a reflection optical signal of the detection optical signal reflected by a first to-be-bonded die, and determine a first deviation value between a current position of the first to-be-bonded die and a first target position according to the received reflection optical signal. The second alignment assembly is configured to determine a second deviation value between a current position of a second to-be-bonded die on the wafer and a second target position.