Bond Clip Lead Frame Alignment for Stable Reflow Packaging
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Solution Overview
Problem
The positioning of bond clips during the reflow process in semiconductor packages is unstable, leading to potential malfunction due to drifting, which affects the quality and yield of the final product.
Innovation Solution
The implementation of alignment features on the bond clip mounting portion of the lead frame, such as protrusions and notches, to restrict the translational and rotational movement of the bond clip, ensuring it remains in the correct position during the reflow process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bond clips are used to connect semiconductor die to lead frame, then thermal performance and current capacity are improved, but positioning stability deteriorates during reflow process
Solution Approach 1:
Alignment features (protrusions and notches) are pre-formed on the lead frame before bond clip attachment. These features guide and constrain the bond clip into the correct position before soldering occurs, preventing drift during the subsequent reflow process.
Solution Approach 2:
The alignment features act as an intermediary mechanism between the lead frame and bond clip. The protrusions and notches provide mechanical guidance and confinement, mediating the positioning relationship and preventing direct drift of the bond clip during solder reflow.
2Manufacturing precision
If alignment features are added to the lead frame, then bond clip positioning precision is improved, but device complexity increases
Solution Approach 1:
The alignment feature is segmented into two distinct components: protrusions that extend from the lead frame and notches that receive the bond clip. This segmentation allows each feature to perform its specific function (guidance and confinement) while maintaining overall simplicity of the lead frame structure.
Solution Approach 2:
Alignment features are added only at the specific bond clip mounting portion of the lead frame, not throughout the entire device. This localized addition provides necessary positioning precision only where required, minimizing the overall increase in device complexity.
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 configuration enhances thermal performance and current capacity while preventing bond clip misalignment, thereby improving the quality and yield of semiconductor packages.
Implementation Method 1
during the reflow process of the solder the bond clips will start to drift due to the melting and liquefication of the solder
Data Source
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AI summary
A semiconductor package and a method of manufacturing one, as well as a lead frame, wherein the semiconductor package comprises such lead frame at least comprising a die pad mounting portion and a bond clip mounting portion. The lead frame exhibits a longitudinal dimension and a transverse dimension oriented perpendicular to the first longitudinal dimension. The semiconductor package further comprises a semiconductor die having a first die side mounted to the die pad mounting portion and a second die side opposite to the first side, and a bond clip exhibiting a first longitudinal dimension and a second longitudinal dimension oriented perpendicular to the first longitudinal dimension. The bond clip has a first clip portion mounted to the bond clip mounting portion of the lead frame using solder and a second clip portion mounted to the second die side of the semiconductor die, wherein the bond clip mounting portion of the lead frame is provided with alignment features structured to prevent displacement of the bond clip in both the longitudinal and the transverse dimension, and to confine the solder on the bond clip mounting portion.