Interposer Lateral Test Pads for Circuit Board Density
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In high-integration circuit boards, the presence of test pads on the surface reduces the number of electronic components that can be installed due to their occupation of wiring areas, leading to space constraints and potential damage from repeated probing.
Innovation Solution
A circuit board assembly that incorporates an interposer with test pads disposed on its lateral surface, allowing for increased component density and robust testing without occupying valuable wiring space, and featuring a shielding layer for protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If test pads are disposed on the front or back surface of the circuit board, then testing of electronic components can be performed, but the wiring area is reduced and fewer electronic components can be installed
Solution Approach 1:
The test pads are moved from the two-dimensional surface (front or back surface) to the three-dimensional lateral surface of the interposer. This dimensional transition allows test pads to be positioned on the side walls of the interposer, completely separating them from the wiring areas on the circuit board surfaces, thus resolving the space conflict between testing functionality and component installation area.
Solution Approach 2:
An interposer is introduced as an intermediary component between the first and second circuit boards. The test pads are disposed on the lateral surface of this interposer, which acts as a mediator to provide testing functionality without directly occupying space on the circuit board surfaces. The interposer serves as a platform that enables both signal transmission and testing while preserving the circuit board wiring areas.
2Reliability
If test pads are disposed on the circuit board surface, then testing can be performed, but the test pads are susceptible to damage from repeated probing
Solution Approach 1:
The interposer serves as a protective intermediary that carries the test pads on its lateral surface. This positioning protects the test pads from direct exposure to probing operations on the circuit board surface. The interposer structure provides mechanical support and protection, reducing the susceptibility of test pads to damage from repeated probing while maintaining testing functionality.
3Strength
If the thickness of test pads is increased to protect them from damage, then durability improves, but the overall thickness of the circuit board assembly increases
Solution Approach 1:
By moving test pads to the lateral surface of the interposer, the design eliminates the need to increase test pad thickness for protection. The protective function is achieved through spatial repositioning rather than dimensional thickening. This allows the assembly thickness to remain minimized while test pad durability is maintained through their protected position on the interposer side walls.
Data Source
AI summary
A circuit board assembly allowing a higher population density of electronic components on the board includes a first circuit board, a second circuit board, and an interposer electrically connecting the first circuit board and the second circuit board. The interposer includes a substrate sandwiched between the first circuit board and the second circuit board, the substrate includes a first surface facing the first circuit board, a second surface facing the second circuit board, and a lateral surface connecting the first circuit board and the second circuit board. It is the lateral surface which carries a test pad, allowing all testing of components to be done on the test pad.