Reuben Hale, P.E.
Ph: (510) 507-1300
We have provided strain gage services to compliment our analysis in many areas of the electronics industry. This includes R&D of the many high resolution tools and processes of the semiconductor industry, to the product level of the electronics industries.
In the semiconductor industry, at the R&D phase, we have used strain gages to help develop the cutting edge high-tech semiconductor equipment that is part of the effort to produce electrical components of ever diminishings size. As vibration consultants in the semiconductor industry for over 3 decades we have been involved in many unique projects where strain is of interest. In validating and trouble shooting a design we may use stain gage testing, in conjunction with our Vibration Testing Techniques, to deduce the force transmission paths, or to estimate vibration isolation effectiveness. In this area the stain gages have been used to determining the load acting on the vacuum chamber of a scanning electron microscope from a novel turbo-pump isolation system. Micro-vibration limits how small lines can be etched, or how well a tool can resolve an image. Design for mitigation of vibration is a major consideration.
|Semiconductor cleanrooms contain some of the most sophisticated technologies, we have designed tests for many of these tools||Scanning Electron Microscope (SEM) Image, showing image disturbance|
Printed Circuit Board Strain Testing - Components are attached to printed circuit boards, PCBs, by solder connections of various kinds. During assembly, installation, shipping, and/or use the PCBs may bend and strain the solder joints leading to immediate failure, or an unreliable product down the road. We have performed strain measurements to determine the risk of failure to mounted electronic components on printed circuit boards. The standard we often test to requires measurement of both the principle strain and the time rate of change of strain, Strain Rate, characterized for various parts of the manufacture and assembly process. The risk of weakening, or failing, a solder joint depends not only on the strain levels, but on the rate of change of strain level, as the elasticity of the solder joint is, apparently, frequency dependent. One particular test procedure we use follows standard IPC/JEDEC-9704A, 2012 – February, titled Printed Circuit Assembly Strain Gage Test Guideline. The allowable strain levels, for instance, are provided in IPC-WP-011, titled Guidance for Strain Gage Limits for Printed Circuit Assemblies(Rate Limited), but our client may have their own allowable limits as well that they have derived through testing of their product.
|Strain gage rosettes on PCB for testing solder ball joint strains as per IPC-WP-011|
Based on IPC/JEDEC-9704A, the highest priority components to measure are the components that utilize ball grid array (BGA) connections. Strain signals were measured from each of the three strain signals coming from each of the four rosettes mounted near the four corners of the graphics processor chip. The raw strain signals were digitally processed in real-time to compute the two principal strain signals and the strain rates.
|Strain and Strain Rate, Time Domain Signals|
|Strain vs. Strain Rate for IPC-WP-001|
|Strain Measurement on PC-board Investigating Solder Ball Connection Strains in Various Loading Configurations|
- Strain Gage Testing Services Topics Include:
Overview, Rotating Machinery, Medical Device, Power Generation, Electronics-PCBs Semiconductor, Food Industry, Auto Industry