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Interconnect Stress Test Technology

For the printed wiring board (PWB), Interconnect Stress Test (IST) Technology performs a much-needed accelerated reliability/performance assessment, assembly, and end-use industries that is presently unavailable with traditional accelerated stress testing and microsection analysis. The accelerated stress testing is performed within a similar time frame and cost to traditional Microsectioning.

Meeting IPC compliancy to TM-650 2.6.26 in 2000, IST is the new industry-standard test method for the assessment of PWB interconnect reliability. It is an accepted accelerated stress test method (TM-650 - Method 2.6.26) for the assessment of Plated-Through Holes (PTH) and inner layer to PTH barrel inter-connections.

Interconnect Stress Testing (IST) technology was original developed from the electrical stress testing concept called "power cycling," developed by Mr. Rama Munikoti (et. al.) at Northern Telecom (Nortel) in the mid 80’s. Our IST developers (who also worked at Nortel at that time) had the responsibility of manufacturing the various types of test vehicles, with known good and bad levels of quality, specifically in the drilling and Plated-Through Holes (PTH) process. The different quality conditions supported the viability for the original power cycling concept.

The principles behind Interconnect Stress Testing (IST) are quite interesting and surprisingly simple. The IST system automatically passes a predetermined constant DC current through a specifically designed PWB interconnect test vehicle (coupon), the current elevates the temperature of the metals and adjacent materials. The temperature to which the coupon is heated is directly proportional to the measured resistance and the amount of current that is passed through the conductors, pads, and holes.

Learn more about IST Technology

IST Features, Applications, and Benefits






Automated Interconnect Stress Testing of PWBs

Evaluation of PWBs' quality, reliability and life.

Provides objective evidence of the overall quality of PWBs

Simplified Controls and Easy to Understand Graphs

Ideal for technician level operation

Reduces error, down time and misinterpretation

Flexible Testing Parameters

Specialized, Modified and Directed Studies

Allows the ability to accelerate the failure relative to the use environment temperatures






Tests the Integrity of the PTH and Internal Interconnections

Testing the strength of the PTH barrel and inter-layer connections

Objective, quantifiable and repeatable evidence of the quality of PTH and internal interconnections.

Objective Results

Product evaluation, troubleshooting, process control

Removes the dependence on subjective evaluations

Statistically Significant Sample Sizes

Process and Product analysis, MRB, CAR, First Article Acceptance

Assures that sample results better represent the population being tested






Determine Cycles to Failure Under Different Test Conditions

Evaluation of PWBs ability to function after simulated Assembly and Rework

Allows objective ranking of a PWBs longevity in the field by measuring cycles to failure

Determines the Exact Cause of Failure

Finding causes of failure for Procurement, Process, Material & Design Evaluations

Allows the precise and exact determination of the cause for failure

Determination of Hidden or Latent Modes of Failure That Have Not Been Expressed

Finding causes of failure for Procurement, Process, Materials, & Design Evaluations

Allows the evaluation and anticipation of undemonstrated defect that are developing

Standardized by IPC 650 TM 2.6.26

Establishes an Industry Standard this can be used within the Electronics Industry

Assurance that methods are consistent with industry reviewed & approved criteria.

Quick, Repeatable and Reproducible Results

A practical test for quick turn, fast paced OEMs, CMs, Fabricators & Support Industries

Real Time Data, Problems are found quickly usually within 24 hours of testing

Data for Individual or Grouped Coupons

Directed Studies or Overview Evaluations of Material, Design or Process

Allow flexibility in data review and analysis

Precise Identification of Failure Modes

For finding, evaluating and resolving exact causes of failure

Unparallel insight to specific causes of failure, and the identification of latent defects

Precise Failure Location

For finding, evaluating and resolving exact causes of failure

Examination of the specific PWB feature (PTH, VIA, Interconnect) that is failing.

Simulate the Stress of Assembly and Rework

Product Life Studies, Reliability Evaluations, Mean Time to Failure Investigations

Produces data that better represents real environment conditions in a standardized and controlled method