Circuit Board Through-Holes for Void-Free Semiconductor Encapsulation
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Solution Overview
Problem
Conventional semiconductor devices face issues with void formation due to residual air trapped between the semiconductor chip and the circuit board, leading to reduced reliability and difficulty in mounting on micro-shaped electronic devices.
Innovation Solution
The semiconductor device incorporates through-holes in the circuit board to discharge residual air externally, forming a resin-filled portion inside the through-holes to enhance adhesive strength and prevent solid resin overflow, allowing easier mounting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If through-holes are formed in the circuit board to discharge residual air externally, then void formation is suppressed, but solid resin overflow occurs on the lower surface of the circuit board
Solution Approach 1:
The patent extracts the harmful solid resin overflow from the lower surface of the circuit board by designing the through-holes to extend only partially through the thickness of the circuit board, or by forming the through-holes at positions where resin overflow can be easily removed without affecting mounting operations. This allows the beneficial air discharge function to be maintained while eliminating the detrimental resin accumulation.
Solution Approach 2:
The patent applies local quality by varying the depth, position, or dimensions of through-holes in different regions of the circuit board. Specifically, through-holes are designed with different characteristics in areas where air discharge is critical versus areas where resin overflow control is prioritized, allowing optimized performance for both air evacuation and preventing mounting interference.
2Reliability
If resin flows back to the lower surface of the circuit board through through-holes, then air discharge is effective, but adhesive strength between circuit board and encapsulating resin layer decreases
Solution Approach 1:
The patent applies preliminary action by forming the through-holes with specific depth and positioning before the encapsulating resin is fully cured. The through-holes are designed to allow air discharge during the resin filling process while maintaining sufficient resin flow to the lower surface to ensure adequate adhesive bonding. The hole dimensions and positions are pre-calculated to balance air evacuation needs with adhesive strength requirements.
3Reliability
If through-holes are formed to discharge residual air, then void formation is suppressed, but device complexity increases
Solution Approach 1:
The patent transforms the discrete through-hole structure into a porous or mesh-like pattern that provides multiple air discharge pathways. This porous configuration allows efficient air evacuation through distributed channels while maintaining the structural integrity and aesthetic appearance of the circuit board, reducing the visual and structural complexity compared to large, obvious through-holes.
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 design effectively suppresses void formation, improves adhesive strength between the circuit board and encapsulating resin layer, and facilitates easier mounting on micro-shaped electronic devices.
Implementation Method 1
the encapsulating resin first flows in a relatively wide flow range region other than the first encapsulating space, and then flows from four directions of a side surface of the semiconductor chip toward a center of the first encapsulating space
Data Source
AI summary
The adhesive strength and ease of mounting between a circuit board and an encapsulating resin layer are improved and the occurrence of voids is suppressed. A semiconductor device includes a semiconductor chip, a circuit board, and an encapsulating resin layer. The encapsulating resin layer is formed in an encapsulating space including a first encapsulating space formed between the circuit board and the semiconductor chip and a second encapsulating space covering the semiconductor chip. The circuit board has one or more through-holes penetrating from a first surface facing the semiconductor chip toward a second surface, opposite to the first surface, so that the first encapsulating space communicates with the outside of the circuit board. A resin-filled portion formed of the encapsulating resin is formed inside a through-hole, and the circuit board does not have encapsulating resin on the second surface.