Flexible Metal Wire Mounting Pin for Thermal Stress Relief
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing integration of semiconductor devices leads to significant size growth, causing soldered connections between electronic components and printed circuit boards to break due to differences in thermal expansion coefficients, resulting in malconnections or disconnections.
Innovation Solution
A printed circuit board with conductive component mounting pins made of flexible, elastic materials, such as metal wires, which can be formed in various shapes and connected to electronic components using wire bonding technology, providing mechanical energy absorption and reducing thermal expansion-related issues through mechanical contact instead of soldering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If soldering is used to connect electronic components to printed circuit board, then electrical connection is established, but the connection breaks due to thermal expansion differences
Solution Approach 1:
The patent changes the material parameter of the mounting pin from rigid solder to a flexible material that can withstand thermal expansion differences. The mounting pin is made of a material with appropriate elasticity and flexibility to absorb thermal stress while maintaining electrical connection.
Solution Approach 2:
The mounting pin uses a composite structure combining flexible material with conductive properties. This allows the pin to both absorb mechanical stress from thermal expansion and maintain reliable electrical connection to the electrode pad.
2Strength
If rigid solder joints are used, then strong electrical connection is achieved, but the connection is vulnerable to thermal stress
Solution Approach 1:
The patent changes the mechanical parameter of the connection from rigid to flexible by using a mounting pin made of elastic and flexible material. This flexibility allows the connection to accommodate thermal expansion differences between the component and printed circuit board.
Solution Approach 2:
The mounting pin functions as a flexible element that can deform elastically to absorb thermal stress. The flexible material allows the pin to bend and stretch with thermal expansion while maintaining continuous electrical contact with the electrode pad.
3Productivity
If component size increases for higher integration, then functionality improves, but thermal expansion differences increase
Solution Approach 1:
The patent changes the material properties of the mounting pin to have appropriate elasticity and flexibility parameters that can compensate for increased thermal expansion stress. The pin material is selected to have thermal and mechanical properties that match both the large component and the printed circuit board.
Solution Approach 2:
The mounting pin acts as an intermediary element between the large integrated component and the printed circuit board. It mediates the thermal expansion stress by absorbing and distributing the mechanical stress, preventing direct transmission of stress that would cause solder joint failure.
4Reliability
If flexible mounting pins are used, then thermal expansion stress is absorbed, but manufacturing complexity increases
Solution Approach 1:
The patent changes the material parameters of the mounting pin to achieve the desired flexibility and elasticity. By selecting materials with appropriate physical properties, the pin can absorb thermal stress without requiring complex structural designs, keeping the overall device complexity manageable.
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
The solution effectively decreases malconnections or disconnections caused by thermal expansion differences, maintaining reliable electrical connections and avoiding thermal budget issues during reflow processes, while allowing for flexible design applications.
Implementation Method 1
said component mounting pin may be made of a material with suitable properties such as flexibility, elasticity and pliability
Implementation Method 2
a mechanical element capable of absorbing mechanical energy applied to either of or both of a semiconductor apparatus and a printed circuit board through elasticity or deformation
Implementation Method 3
a conductive material to connect with an electronic component
Data Source
AI summary
A printed circuit board according to the present invention is a printed circuit board (4) including a component mounting pin (1) made of a metal wire to connect with a semiconductor chip (10). The semiconductor chip (10) is a surface mounting type semiconductor chip having an electrode pad on its mounting surface for use in a flip-chip mounting system. The component mounting pin (1) is formed by using wire-bonding technology. This printed circuit board (4) is able to decrease malconnections or disconnection caused by a difference between the coefficients of thermal expansion of the semiconductor chip (10) and the printed circuit board (4).