Printed circuit board with integral strain gage

Abstract

An integral strain measurement layer for use in an assembly printed circuit board to provide for strain measurement on the printed circuit board. The strain measurement layer includes an insulating layer having a top surface and a bottom surface, a strain sensitive layer of metallic foil adhered to the top surface of the insulating layer for measuring strain associated with the printed circuit board, and a copper coating disposed on the strain sensitive layer of metallic foil.

Description

BACKGROUND OF THE INVENTION [0001] The present invention relates to a printed circuit board with an integral strain gage. Although the present invention addresses numerous problems, specific problems related to the manufacturing of printed circuit boards are discussed herein to provide a background of the invention. [0002] During printed circuit board manufacturing, it is advantageous to measure strain associated with a printed circuit boards. Strain measurements can be used for stress analysis purposes. During the manufacturing processes printed circuit boards undergo a variety of operations that can be stressful. For example populating a board during one manufacturing operation may cause damage to connections made in a previous manufacturing operation. Locating and monitoring areas where strain is being produced on a printed circuit board is desirable. Knowledge regarding strain can be used to assess electronic component failure modes within a printed circuit board to thereby alte...

AI Technical Summary

Benefits of technology

This solution reduces installation costs and improves measurement accuracy by allowing flexible placement of strain sensors within the printed circuit board, enhancing manufacturing process adjustments and sensor functionality for stress analysis.

Problems solved by technology

During the manufacturing processes printed circuit boards undergo a variety of operations that can be stressful.

For example populating a board during one manufacturing operation may cause damage to connections made in a previous manufacturing operation.

In the case of prior art strain gages, there is a significant installation cost associated with placing a strain gage on a printed circuit board.

This step is performed by a technician which is time-consuming and costly.

This type of labor intensive installation process is not consistent with the goals of an automated assembly process or a high volume PCB manufacturing environment.

Moreover, because an automated process is not used the results obtained from strain gages installed in this manner may not be as accurate or useful as desired due to inconsistencies between installations.

This approach has allowed some use of printed circuit board manufacturing techniques, however there are significant disadvantages.

In particular deposited metal does not provide the requisite strain-sensitive properties that may be required in more sensitive applications.

Also, although printed circuit board manufacturing techniques are used, the use of a metal deposition step for the strain gage is a significant addition to the manufacturing process that may be cost prohibitive in particular applications.

A further problem is that with the prior art approaches there are numerous limitations as to where strain can be measured.

Strain sensors can not be located in positions which are not readily accessible.

Thus, despite these varying approaches used in the prior art, problems remain.

Images