Semiconductor Mounting Substrate Frame Dummy Pattern Warpage
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Solution Overview
Problem
Thinner semiconductor substrates with higher wiring density experience warpage, leading to adhesive leakage and air entrainment under semiconductor elements, which reduces bonding strength and reliability of semiconductor devices.
Innovation Solution
A substrate with a frame-like dummy pattern on the semiconductor element mounting region, not connected to the wiring patterns, is used to prevent adhesive leakage and air entrainment, featuring a thicker dummy pattern to maintain adhesive thickness and suppress warpage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If substrates are reduced in thickness to meet demand for thin semiconductor devices, then device thickness is reduced, but warpage increases causing adhesive application instability
Solution Approach 1:
The patent applies local quality by creating a dummy pattern with different properties (higher thickness, different material composition) in the adhesive application region compared to the rest of the substrate. This localized structural modification specifically addresses warpage in the critical mounting area without changing the overall substrate thickness, thereby maintaining thin device profile while improving local stability for adhesive application.
2Productivity
If wiring density is increased on thin substrates to accommodate more pins, then pin count is increased, but warpage and adhesive application difficulty increase
Solution Approach 1:
The patent segments the substrate into functionally distinct regions: high-density wiring areas for signal transmission and a dummy pattern region for adhesive application. This segmentation allows independent optimization of each region - wiring density can be maximized in functional areas while the dummy pattern provides a controlled, lower-density area that stabilizes adhesive application, thereby resolving the conflict between high pin count and adhesive precision.
3Ease of operation
If adhesive viscosity is reduced to improve assembly stability, then assembly stability is improved, but adhesive leakage increases
Solution Approach 1:
The dummy pattern acts as an intermediary structure between the adhesive and the substrate surface. It provides a controlled interface that retains low-viscosity adhesive through its specific geometric configuration and material properties, preventing leakage while maintaining the assembly stability benefits of reduced viscosity adhesive.
4Strength
If paste adhesive is applied to mount semiconductor elements, then bonding is achieved, but adhesive leaks through gaps causing thin and uneven adhesive layers
Solution Approach 1:
The dummy pattern is designed to preemptively counteract adhesive leakage by creating a physical barrier and controlled retention structure before adhesive application. Its geometry and material properties are specifically engineered to hold the adhesive in place, preventing it from leaking through gaps and ensuring uniform thickness, thereby maintaining bonding strength while improving layer uniformity.
Data Source
AI summary
The present invention provides a semiconductor element mounting substrate 101 including: a base substrate 1 having a region 2 for mounting a semiconductor element 11, the region 2 being set on the major surface of the base substrate 1; a plurality of wiring patterns 3 formed on the base substrate 1 and connected to the semiconductor element 11; and a dummy pattern 8 formed like a frame in the region 2 for mounting the semiconductor element 11 and not connected to the wiring patterns 3.