Electronic Component-Embedded Board Warpage Suppression
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Solution Overview
Problem
Conventional methods for manufacturing electronic component-embedded boards result in warpage issues due to uneven thermal expansion and contraction, leading to manufacturing and processing problems such as conveyance failure, positional accuracy issues, and reduced yield and reliability.
Innovation Solution
A method involving a substrate with an electronic component and a member having a specific thermal expansion coefficient relationship (α1 < α3 and α2 < α3) is used, where the member is mounted on unmounted substrate portions to form an insulating layer, which covers the component and reduces thermal expansion differences, alleviating internal stress and warpage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional worksheet manufacturing method is used to manufacture an electronic component-embedded board, then the board can be produced, but warpage occurs due to nonuniform thermal expansion and contraction between the electronic component and substrate
Solution Approach 1:
The patent applies local quality by introducing a frame-like conductive pattern with specific thermal expansion characteristics at the peripheral region of the substrate. This local structural modification creates a stress-compensating mechanism that balances the nonuniform thermal expansion between the electronic component (with lower thermal expansion coefficient) and the substrate (with higher thermal expansion coefficient), thereby suppressing warpage while maintaining overall manufacturing simplicity
Solution Approach 2:
The patent utilizes parameter changes by carefully selecting the thermal expansion coefficient of the frame-like conductive pattern material to fall between that of the electronic component and the substrate. This intermediate parameter value allows the frame structure to act as a thermal expansion buffer, absorbing differential stress and preventing warpage during temperature variations in the manufacturing process
2Volume of moving object
If the worksheet is thinned to 500 μm or less to meet smaller size requirements, then the profile is thinner, but excessive warpage of several tens of millimeters occurs
Solution Approach 1:
The frame-like conductive pattern is strategically positioned at the peripheral region of the thinned substrate to provide localized structural support and stress compensation. This local reinforcement is particularly effective for thin substrates (500 μm or less) where uniform support is difficult to achieve, preventing excessive warpage while maintaining the thin profile required for modern electronic devices
Solution Approach 2:
The patent employs composite material principles by combining the substrate, electronic component, and frame-like conductive pattern into a multi-material structure with complementary properties. The frame structure made of material with intermediate thermal expansion characteristics creates a composite system that balances the thermal and mechanical properties of the thin substrate assembly, preventing warpage without compromising thickness reduction
3Manufacturing precision
If supporting members are used to grasp the worksheet from the outside to suppress warpage during insulating layer formation, then warpage is suppressible, but the manufacturing process becomes complicated and productivity decreases
Solution Approach 1:
The frame-like conductive pattern serves a dual function: it is both a functional electrical interconnection element and a self-supporting structure that suppresses warpage during manufacturing. This self-service approach eliminates the need for external supporting members or grasping mechanisms, keeping the manufacturing process simple and maintaining high productivity while effectively controlling warpage
Solution Approach 2:
The frame-like conductive pattern is designed to perform multiple functions simultaneously: providing electrical interconnection, serving as a thermal expansion compensation mechanism, and acting as a self-supporting structure during manufacturing. This multi-functionality eliminates the need for separate supporting members, reducing process complexity while maintaining warpage suppression capability
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 approach effectively suppresses warpage, enhances substrate strength, improves handleability, and increases process yield and mounting reliability without complex processes, thereby enhancing productivity and economic efficiency.
Implementation Method 1
degrees (levels) of thermal expansion and thermal contraction caused by heat applied during the formation of an insulation layer or the like differ between an electronic component-mounting portion (a region of a substrate at which an electronic component is to be mounted) and an unmounted portion (a region of a substrate at which the electronic component is not mounted)
Data Source
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AI summary
A method of manufacturing an electronic component-embedded board is provided which is capable of suppressing warpage without requiring complicated processes at low cost and which offers high productivity and economic efficiency. A worksheet 100 includes insulating layers 21 and 31 on one surface of an approximately rectangular substrate 11, and an electronic component 41 and a plate-like frame member (member) 51 embedded inside the insulating layer 21, wherein the plate-like frame member 51 satisfying the relationship represented by the following formula (1) :α1 < α3 and α2 < α3 ... (1), is mounted on an unmounted portion of the electronic component 41 on the substrate 11. In the formula, α1, α2 and α3 respectively denote the linear coefficients of thermal expansion (ppm/K) of the electronic component 41, the plate-like frame member 51, and the substrate 11, the respective wiring layers or the respective insulating layers.