Diodes Shorted? Overheating?, Charring, Poor Performance?
Diode Failure Symptoms: Shorted, Thermal Runaway, Overheated, Charred, No Mechanical Integrity, No Obvious Symptom

Most Likely Cause: Poor Die Attach Soldering. Thus, Solder Voids Are Created Which Prevent Heat Dissipation, Causes Hot Spots, Die Solder Reflow, and Ultimate Diode FAILURE.

Download a Copy of This Diode Failure Analysis

This poor die attach soldering problem is much, much, more serious, and a lot more common than you might think. In the photographs below, diodes produced by a prestigious multinational semiconductor manufacturer were examined for die solder quality. These diodes were provided by one of our potential customers who have experienced serious quality problems and premature failures.

DIODE PRIED OPEN

SECTION B

SECTION A

LARGE VOID AREA REVEALED IN THE SOLDER LAYER

This is a A VERY COMMON PROBLEM. In The Close-ups to The Right, The Crater-Like Areas are Solder Voids. The Black Areas Are The Silicon Die.

NUMEROUS SOLDER VOIDS CAN CLEARLY BE SEEN IN THESE CLOSE UPS. These Voids 1) Greatly Weaken The Diode's Mechanical Integrity, 2) Increase The Forward Voltage Drop, and 3) Severely Restrict The Dissipation of Heat From The Die. Restricted Heat Dissipation causes the Diode to Operate at Elevated Temperatures Which Could Lower Its Current Handling and/or Cause Premature Failure.

Another common, but much more serious, situation.

DIODE PRIED OPEN

SECTION B - ONLY SOLDER

SECTION A- DIE SIDE

Diode Separation Has Occured Completely at The Solder-Die Interface!

CHIP IS INTACT IN SECTION A
SOLDER ONLY COVERS ~ 50% OF DIE

The Solder Either Failed to Wet And, Hence, Bond to The Die's Surface (Surface Outlined in Red on Section B) or is riddled with voids. As a Result, This Diode Has Absolutely No Mechanical Strength And May Fail On Impact if dropped or Struck. Additionally, The Thermal Resistance of This Diode is so High that Thermal Runaway is a Certainty.

THIS IS THE HIGH QUALITY DIOTEC DIFFERENCE - VOID FREE DIE SOLDERING.

DIODE PRIED OPEN

SECTION A

SECTION B

DIODE BREAKS AT SILICON DIE

NO VISIBLE VOID AREAS
OR VOIDS (See Close-ups).

Superior Soldering Results in SUPERIOR MECHANICAL STRENGTH, SUPERB HEAT DISSIPATION, and LOWER FORWARD VOLTAGE DROP

DIOTEC utilizes an advanced, computer controlled, vacuum die soldering process, which enables silicon chips to be soldered to metal with exceptional consistency and void free quality. Thus, DIOTEC diodes and bridge rectifiers have unmatched heat dissipation, cooler junction temperatures, lower leakage currents, and reduced thermal stress. Additionally, the high quality die attachment allows the diodes survive mechanical shock without bond failure, another common problem with most offshore "cheap" diodes.

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Please don't hesitate to contact:

JOE LIN

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310-767-1052
310-767-7958

Download a Copy of This Diode Failure Analysis
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