| CAF, SIR and ECM/EMR Testing
As spacing and part sizes on PCB’s decrease, the need to verify Conductive Anodic Filament (CAF), Surface Insulation Resistance (SIR) and Electrochemical Migration Resistance (ECM/EMR) have become increasingly necessary. These tests use high temperature/humidity environments in order to understand a product’s reliability by accelerating any failures that might happen. Electrical attributes are evaluated during or after accelerated environmental exposures to further ascertain the product's performance under these severe conditions.
Conductive Anodic Filament (CAF) formation is a well-studied phenomenon that is driven by chemical, humidity, voltage, and mechanical means. It is characterized by a sudden loss of insulation resistance that happens internally in the PCB. CAF dendrites can form between adjacent plated through holes (PTH), or between a plated through hole and a line on the PCB. Plating chemistry, material consistency, damage from multiple soldering steps, and excessive voltages (beyond designed voltages) accelerate the onset of CAF. The mechanism of CAF is an electro-chemical transport of ions across an electrical potential between anode and cathode.
Surface Insulation Resistance (SIR) testing is a methodology used to characterize the PCB manufacturing and electronics assembly process residues and their impact on reliability. It is usually performed on industry standard test board coupons containing patterns, typically interlocking comb test patterns designed for process testing purposes. The patterns are exposed to a high humidity environment which mobilizes any surface contaminates and reduces the insulation resistance of the test pattern.
Qualify, Monitor and Control the
Cleanliness of Assembly Processes
with the New IPC-9202 Standard
Gain Reliability Through Verification
Implementing a new assembly process step or chemistry can be detrimental to end-product performance. The new IPC-9202 is designed to help validate and record the effects of new processes on the surface insulation resistance (SIR). Residues left on boards after the assembly process could cause contamination and corrosion that can affect the long-term reliability of the assembly.
Microtek provides the highest level of Surface Insulation Resistance (SIR) testing available today
We can completely qualify and verify any new processes or changes to existing assemblies.
Our tests for the new IPC-9202 standard utilize the IPC-B-52 test vehicle (coupon) - intended to be representative of the electronic circuits that are in your production.
Our Lab Technicians and Testing Processes are Second-to-None, the Industry Standard
1. Experts in the detection of deleterious effects resulting from solder flux or other process changes
2. Detection of harmful residues left on external surfaces after soldering
3. Document and analyze any unwanted electrochemical reactions that may adversely affect reliability
The test may be used for:
- Process or a change in process qualification
- Demonstrating a "newly proposed" manufacturing or assembly process
- Verification of Process cahnges that produce hardware with acceptable end-item performance related to cleanliness
- Process characterizations, including development of new processes or improvements to an existing process
Industry Best-practices, Test Methods and Reporting
Through our active involvement and leadership, Microtek's Team helped establish the standards, processes and test methods for IPC-9202 yielding both quantitative and qualitative data. Microtek's SIR testing will ensure your assemblies meet the new standards.
Contact Us Today - Toll Free In U.S. 1-800-878-6601
Microtek is available to discuss our SIR processes and applicable documentation with current and prospective customers including Contract Manufacturers and OEMs.
|
