Flexible Printed Board Tamper Detection for Compact Card Readers
Solution Overview
Problem
Conventional card readers with tamper detection patterns require a second case body to cover the printed board, making it difficult to reduce the size of the structure for ensuring security, as the flexible printed board is stuck to this case body and not directly fixed to the main printed board.
Innovation Solution
A printed board design featuring a main printed board with a flexible printed board that is directly fixed to the main board, incorporating a box part and fixed parts that extend to the outer periphery, with tamper detection patterns for detecting disconnection and short circuits, allowing for enhanced security without the need for a second case body.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the flexible printed board is stuck to the second case body to cover the printed board, then security of the printed board is ensured, but the size of the structure cannot be reduced
Solution Approach 1:
The invention extracts and eliminates the second case body from the structure. Instead of sticking the flexible printed board to the case body, the flexible printed board is directly fixed to the printed board, removing the intermediate case body component and reducing overall structure size while maintaining security function
Solution Approach 2:
The invention merges the flexible printed board directly with the printed board by providing a fixed part that extends from the flexible printed board to the outer peripheral side and is fixed to the printed board. This integration eliminates the need for the second case body and reduces structural complexity
2Reliability
If the flexible printed board is stuck to the second case body, then the printed board is covered for security, but the structure becomes more complex
Solution Approach 1:
The second case body is completely removed from the design. The flexible printed board directly contacts and is fixed to the printed board, eliminating the need for the case body while preserving the tamper detection functionality through the flexible printed board's own structure
Solution Approach 2:
The flexible printed board serves multiple functions: it provides tamper detection through its own tamper detection patterns, acts as the protective covering, and serves as the structural connection element. This multi-functionality eliminates the need for separate case body components
Data Source
AI summary
A printed board includes a main printed board, and a flexible printed board fixed to the main printed board. The flexible printed board includes a box part formed in a box shape whose main printed board side is opened and a fixed part extended to an outer side and fixed to the main printed board. The flexible printed board is formed with a plurality of tamper detection patterns for detecting at least one of disconnection of the tamper detection pattern itself and a short circuit with other tamper detection pattern. An internal land of the tamper detection pattern is connected with the main printed board and is disposed on an inner side of the box part, an external land of the tamper detection pattern is formed in the fixed part and is fixed to and connected with the main printed board, and the external lands are insulated from each other.