On-Cavity PCB Interconnect for Reduced Z-Height
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional board-to-board connectors increase the z-height of printed circuit boards (PCBs), which is undesirable for small form factor devices and System in Package devices, as they add vertical height and can lead to impedance discontinuities and crosstalk issues.
Innovation Solution
Implementing on-cavity board-to-board interconnects, where cavities are created in each PCB to expose solder contact points, allowing direct electrical contact without a connector, using techniques like semi-rigid board recess technology and anisotropic conductive films for assembly, which reduces z-height and minimizes impedance discontinuities and crosstalk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional board-to-board connectors are used to interconnect PCBs, then electrical connection between PCBs is achieved, but the z-height of the PCB assembly increases
Solution Approach 1:
The patent removes the traditional connector component from the PCB assembly by excavating cavities directly into the PCB substrate. This extraction of the connector function and integration into the board structure eliminates the additional z-height that connectors would add, while maintaining electrical connectivity through exposed solder pads that mate directly with complementary PCBs
Solution Approach 2:
The patent merges the connector function with the PCB structure itself by creating cavities that expose solder pads. Instead of using a separate connector component, the electrical interconnection function is combined with the board structure, allowing direct board-to-board mating without additional height
2Reliability
If traditional board-to-board connectors are used to interconnect PCBs, then electrical connection between PCBs is achieved, but impedance discontinuities and crosstalk issues occur
Solution Approach 1:
The patent extracts the connector interface and replaces it with direct PCB-to-PCB solder pad contact through excavated cavities. This eliminates the mechanical connector structure that creates impedance discontinuities and crosstalk, providing a more direct electrical path between boards
Solution Approach 2:
The patent applies local quality changes by excavating specific cavities in the PCB substrate to expose solder pads at precise locations. This localized modification creates optimal electrical contact points directly at the board interface, improving impedance matching and reducing crosstalk compared to traditional connector interfaces
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 eliminates the need for connectors, reduces impedance discontinuities, and minimizes crosstalk, enabling more efficient energy transfer and increased pin density without increasing the z-height, thus enhancing the performance and compactness of small form factor devices.
Implementation Method 1
using techniques like semi-rigid board recess technology and anisotropic conductive films for assembly
Data Source
AI summary
A system for board-to-board interconnect is described herein. The system includes a first printed circuit board (PCB) having a first recess along a first edge of the first PCB that exposes a first solder pad on a layer of the first PCB. The system also includes a second PCB having a second recess along a second edge of the second PCB that exposes a second solder pad on a layer of the second PCB. The second recess is complementary to the first recess to allow the first PCB to mate with the second PCB. The first solder pad is aligned with the second solder pad when the first PCB is mated with the second PCB. The system additionally includes an assembly configured to electronically couple the first solder pad with the second solder pad.