Under-fill Element Heated for Flexible PCB Mounting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for mounting electronic devices on printed circuit boards face inefficiencies due to the need for precise alignment and filling of gaps, particularly in limited spaces, and may not securely adhere the device even when the board is flexible or curved.
Innovation Solution
The electronic device features bumps on its lower surface and an under-fill element on its side surfaces, which is heated to form an under-fill layer between the device and the printed circuit board or flexible substrate, enhancing cohesion and allowing for efficient mounting even in constrained spaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional mounting methods are used to secure electronic devices on printed circuit boards, then the device can be mounted on rigid boards, but the mounting process becomes complex and inefficient when dealing with flexible or curved substrates in limited spaces
Solution Approach 1:
The under-fill element is pre-formed and attached to the lower surface of the electronic device before mounting. This preliminary preparation includes creating grooves on the device surface and filling them with under-fill material, which then flows to fill gaps between the device and substrate during mounting, simplifying the overall mounting process especially for flexible substrates
Solution Approach 2:
The under-fill element undergoes phase change from solid to liquid when heated to a predetermined temperature, allowing it to flow and fill gaps between the electronic device and the printed circuit board or flexible substrate, then solidifies to provide mechanical support and adhesion
2Reliability
If gaps between the electronic device and printed circuit board are not filled, then the mounting process is simpler, but cohesion and secure attachment are not achieved
Solution Approach 1:
The under-fill element is designed to automatically flow and fill gaps between the electronic device and substrate when heated, without requiring external injection equipment or complex filling processes. The material self-distributes to fill voids and then solidifies to provide mechanical support and adhesion
Solution Approach 2:
The under-fill element utilizes phase transition from solid to liquid state when heated to a predetermined temperature, enabling it to flow and fill gaps between the device and substrate, then solidifies upon cooling to provide mechanical support and adhesion, ensuring reliable attachment
3Manufacturing precision
If precise alignment is required during mounting, then connection accuracy is improved, but the mounting process becomes more time-consuming and less efficient
Solution Approach 1:
Heating the under-fill element to a predetermined temperature causes it to transition from solid to liquid state, enabling automatic flow and gap filling that compensates for minor alignment variations, reducing the need for extremely precise alignment while maintaining connection quality
Solution Approach 2:
The under-fill element acts as an intermediary material between the electronic device and substrate, providing mechanical support and adhesion that accommodates minor misalignments, allowing faster mounting without sacrificing connection precision
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 method improves mounting efficiency and ensures secure attachment of electronic devices on both rigid and flexible substrates, maintaining connectivity despite substrate deformations, and allows for precise alignment and efficient use of space.
Implementation Method 1
heating the under-fill element to a predetermined temperature to form an under-fill layer between the lower surface of the semiconductor chip body and the printed circuit board
Data Source
AI summary
A mounting method of an electronic device includes providing an electronic device which includes a semiconductor chip body including an upper surface, a lower surface opposite to the upper surface, and side surfaces connecting the upper surface and the lower surface, a plurality of bumps disposed on the lower surface, and an under-fill element disposed on at least one side surface. The method further includes mounting the electronic device on a printed circuit board including connecting pads formed thereon. The bumps of the semiconductor chip body are connected to the connecting pads. The method additionally includes heating the under-fill element to a predetermined temperature to form an under-fill layer between the lower surface of the semiconductor chip body and the printed circuit board.