This month we bring to you some innovative rework and repair information including:
On line "Cost of Rework" calculator for helping you with "make" vs "buy" PCB rework and repair decisions
"PCB Pad and Trace Repair Adhesive" study results
A NEW solder tip rinsing method which allows you to use the same soldering tips for both leaded and lead-free solders
Information on lead-free compatible circuit tracks
Hope to see you at either the SMTA Wisconsin Assembly Technology Forum or the Indiana RoHS event!
Bob Wettermann, President
When determining actual rework costs, it is always a good idea to consult with your accounting department. You should obtain from them a "fully burdened overhead" rate per rework associate that can be used as a basis for your calculation. Work with them to obtain the cost of equipment and training. Make sure that you get a handle on damage/scrap, which in many cases is the largest single componant of total rework cost.
Once you have calculated the costs required as inputs to the cost model, you can calculate the costs of a rework job. BEST has worked with a cost accounting firm to develop and research national averages as default values to this model.
Use this tool to help you make well-informed "make" vs "buy" decisions in terms of rework projects. Use the rework calulculator for your current project or to bookmark this location
A new technique which allows you to use the SAME soldering tips in a mixed alloy environment has been confirmed. BEST's newly developed "rinsing" technique allows you to stay within the RoHS guidelines for rework even when switching between lead-based and lead-free solders.
The study, which measured the presence of lead on the tip after subsequent "rinsings", found that a (4) time rinse sufficiently can reduce the lead content to below the RoHS 0.1% lead by weight guidelines. See October's SMT Global Magazine for more details..
See the complete article and description
BEST recently commissioned a study on the different adhesive bonding systems for circuit pad and trace repair. This study compares the results of the two main types of bonding systems-2 part resin/hardener and dry film. In addition, the recently formulated BEST dry film adhesive strength was compared against dry film from company "C".
Previous studies have shown that even under thermal air-air shock conditions from -50?C to 85?C at a 30 minute dwell time for 200 cycles the resin- hardener adhesive system holds up well. The same cannot be said about dry film bonding systems where the reliability of repaired pads, lands and traces did not hold up to such environmental conditions. The variability in the application of pressure as well as the many different tips needed for the variety of surfaces make the results of the "dry film" method variable as well as the process cumbersome.
The BEST Circuit Trace Repair Kit is designed to meet the quality of original trace patterns.
The BEST PCB circuit trace repair kit gives you the tools you need for fast repair and modification of circuit traces. These materials, packaged together and designed by BEST Inc, allows you to meet original PCB quality standards.
The method for repairing damaged circuit traces which are supplied in this kit employs the use of copper circuit tracks which are epoxied to the circuit board. These replacement conductors are the same size as the original. This IPC-recommended technique is preferable to making circuit repairs with jumper wires because it most closely duplicates the original fabrication process.
There are (7) different circuit traces included in this kit making sure you have the trace that you need when you need it. Each of the traces are BOTH lead- free and tin-lead alloy compatible.
See all available circuit tracks