Semiconductor Contact Pad Locking via Pre-Shaped Photoresist
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Solution Overview
Problem
The reliability of semiconductor packages in surface-mount technology is not consistently guaranteed during mounting on printed circuit boards, necessitating an improvement in packaging methods to enhance reliability.
Innovation Solution
A method involving the use of a photoresist layer with pre-shaped sidewalls, which are filled with electrically conductive material to form contact pads with protrusions, providing better locking of the semiconductor chip to the contact pad, and a protective compound that covers the chip and protrusions, enhancing the reliability of the packaged device without increasing contact pad thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional packaging methods are used, then manufacturing simplicity is maintained, but reliability of semiconductor packages during mounting is not consistently guaranteed
Solution Approach 1:
The photoresist layer is pre-shaped with protrusions before the contact pad material is applied. This preliminary action creates mechanical interlocking features that enhance reliability without requiring complex post-processing steps or additional components.
Solution Approach 2:
The photoresist layer is modified locally at specific positions where protrusions are formed, rather than changing the entire structure. This localized modification provides enhanced locking capability at critical interfaces while maintaining simplicity elsewhere in the device.
2Reliability
If photoresist layer with pre-shaped sidewalls is used to form protrusions, then locking mechanism is improved, but manufacturing complexity increases
Solution Approach 1:
The photoresist layer is pre-shaped with protrusions before the contact pad material is applied. This preliminary action creates mechanical interlocking features that enhance reliability without requiring complex post-processing steps or additional components.
Solution Approach 2:
The shape parameters of the photoresist layer are modified to include protrusions with specific geometries. By changing the physical form of the photoresist layer, the locking mechanism is enhanced while the manufacturing process remains relatively simple, as it involves standard photolithography techniques.
3Reliability
If contact pad thickness is increased to improve locking, then reliability is improved, but device size and cost increase
Solution Approach 1:
Instead of increasing locking strength by adding thickness in the vertical dimension, the solution introduces protrusions in the lateral dimension. This dimensional shift allows mechanical interlocking through horizontal features rather than vertical thickness, maintaining device compactness while improving reliability.
Solution Approach 2:
The photoresist layer is pre-shaped with protrusions before the contact pad material is applied. This preliminary action creates mechanical interlocking features that enhance reliability without requiring complex post-processing steps or additional components.
Data Source
AI summary
The invention relates to semiconductor devices and methods of manufacturing. In certain embodiments, a semiconductor device can include: a) a contact pad with pre-shaped sidewalls; b) a semiconductor chip having a terminal that is electrically connected to the contact pad, and c) a protective compound covering the semiconductor chip and at least part of the sidewalls. The sidewall can be rough or the sidewall can be tapered to facilitate locking of the contact pad into the compound.