Electronic Component Built-in Substrate with Displaced Conductive Balls
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Solution Overview
Problem
The challenge in manufacturing electronic component built-in substrates is the difficulty in narrowing the arrangement pitch of solder balls due to the need for larger diameters than the height of semiconductor chips, leading to issues with electrical connections when molding resin is filled between stacked wiring substrates, causing either separation or electrical short-circuits.
Innovation Solution
The introduction of an intermediate wiring substrate with displaced conductive balls allows for a stacked structure where the intermediate substrate absorbs pressure variations, enabling smaller solder ball diameters and maintaining reliable electrical connections by bending to accommodate molding resin filling pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the diameter of solder balls is increased to be larger than the height of semiconductor chips, then the reliability of electrical connection is improved, but the arrangement pitch cannot be narrowed
Solution Approach 1:
The patent divides the single-layer solder ball connection into two separate layers: first solder balls connecting the lower wiring substrate to the intermediate wiring substrate, and second solder balls connecting the intermediate wiring substrate to the upper wiring substrate. This segmentation allows each solder ball layer to be independently positioned, enabling narrower arrangement pitch while maintaining connection reliability.
Solution Approach 2:
The patent transitions from a two-dimensional arrangement (single layer) to a three-dimensional stacked structure by introducing an intermediate wiring substrate. The first and second solder balls are arranged at different vertical levels, utilizing the third dimension (height) to achieve higher connection density without increasing the horizontal arrangement pitch.
2Ease of manufacture
If the interval between molding dies is wider than the designed value, then the molding process is easier, but the lower and upper wiring substrates are forced to expand causing solder balls to separate
Solution Approach 1:
The patent introduces an intermediate wiring substrate that acts as a cushioning layer between the lower and upper wiring substrates. This intermediate layer absorbs and distributes the expansion forces during molding, preventing the solder balls from separating and maintaining electrical connection reliability even when the molding die interval is wider than designed.
Solution Approach 2:
The intermediate wiring substrate serves as a mediator between the lower and upper wiring substrates during the molding process. It absorbs the mechanical stress and expansion forces, protecting the solder ball connections from damage while allowing the molding process to proceed with wider die intervals.
3Length of stationary object
If the interval between molding dies is narrower than the designed value, then the substrate thickness is reduced, but the upper wiring substrate is pushed downward causing solder balls to crash
Solution Approach 1:
The intermediate wiring substrate provides beforehand cushioning by absorbing downward compression forces during molding when the die interval is narrower than designed. This prevents the upper wiring substrate from pushing down on the solder balls and causing them to crash, maintaining connection integrity.
Solution Approach 2:
The intermediate wiring substrate acts as a protective intermediary that absorbs compression forces from the upper wiring substrate during narrow-interval molding. It prevents these forces from being transmitted to the solder balls, avoiding crashes and maintaining electrical connection reliability.
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 solution allows for a narrower pitch of connection parts, increasing the number of signal routes while ensuring reliable electrical connections and preventing separation or short-circuits during resin filling, thus enhancing the performance and integration of semiconductor chips.
Implementation Method 1
the intermediate substrate absorbs pressure variations, enabling smaller solder ball diameters and maintaining reliable electrical connections by bending to accommodate molding resin filling pressures
Data Source
AI summary
An electronic component built-in substrate, includes a lower wiring substrate, an electronic component mounted on the lower wiring substrate, an intermediate wiring substrate including an opening portion in which the electronic component is mounted, and arranged in a periphery of the electronic component, and connected to the lower wiring substrate via a first conductive ball, an upper wiring substrate arranged over the electronic component and the intermediate wiring substrate, and connected to the intermediate wiring substrate via a second conductive ball, and a resin filled into respective areas between the lower wiring substrate, the intermediate wiring substrate, and the upper wiring substrate, and sealing the electronic component, wherein the first conductive ball and the second conductive ball are arranged in displaced positions mutually.