This relates generally to strain gauges, and, more particularly, to strain gauges for monitoring strain in printed circuits.
Electronic devices such as cellular telephones, computers, and other electronic devices contain integrated circuits and other electrical components. Components such as these may be mounted on printed circuits. During drop events and other situations in which an electronic device is subjected to an impact or other conditions leading to elevated stresses, solder joints may be weakened and other faults can develop in the circuitry mounted on a printed circuit. Unless care is taken, stress-induced damage to an electrical component or other circuitry in an electronic device may create reliability issues.
To help understand the way in which strain is distributed to the components in a printed circuit, strain tests may be performed on a test printed circuit board. External strain gauges may be attached to the upper and lower surfaces of the test board in the vicinity of integrated circuits or other components of interest. These strain gauges may be wired to test equipment that gathers strain data. Strain data may be gathered with the strain gauges while applying force to the printed circuit. By analyzing the strain data, printed circuit board designs and component layouts can be refined to enhance reliability.
It can be difficult to gather accurate strain data with this type of approach. Strain measurements from strain gauges mounted on the surface of the printed circuit board may be influenced by the way in which the strain gauges are adhered to the surface of the printed circuit board and other variables that are difficult to control. These strain gauges also do not gather strain data in the field to alert a user or others about the presence of excessive strain.
It would therefore be desirable to be able to provide improved strain gauge configurations for monitoring components on printed circuit boards.