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AUTOCLAVE (AC)/PRESSURE TEMPERATURE HUMIDITY (PTH)
Autoclave is an environmental test that measures device resistance to moisture
penetration and the resultant effects of galvanic corrosion. It is a highly accelerated and
destructive test performed per JEDEC Standard 22B, Method A110 Code C). Conditions
employed during the test include 121°C, 100% relative humidity, and 15 psig. Corrosion
of the die is the expected failure mechanism. Typical test duration is 144 hours.
A device will be considered to have failed the autoclave test if parametric limits are
exceeded or if functionality cannot be demonstrated under normal and worst case
conditions specified in the data sheet. Verified EOS and ESD failures shall not be
considered as legitimate failures, nor will mechanical damage such as cracking of the
package. Cosmetic package defects and degradation of lead finish and solderability are not
considered as a reject criterion.
PRE-CONDITIONING - VAPOR PHASE (VPR) AND INFRARED REFLOW (IR)
Pre-conditioning is a process which simulates the manufacturing steps involved in
mounting and rework of a surface mount device on to the customer's application printed
circuit board. Different methodologies can be employed for this purpose. Infrared Reflow
uses heaters instead of hot fluorocarbon vapor for the reflow. Vapor Phase Reflow(VPR)
is known to be the most contingent stress to the surface mount devices (per JEDEC
Standard 22, Method A112/3). In vapor phase pre-conditioning, different presoak
conditions are defined such as 85C/85% Relative Humidity(RH)(Class I), 85C/60%RH
(Class II), 30C/60%RH (Class III, IV & V) to simulate different environmental
conditions. Devices are exposed to VPR within 4 hours after the completion of the pre-
soaking process. Three cycles of VPR are performed to the parts, 8 to 10 minutes cool
down time is allowed between VPR immersions. Devices are visually inspected for
package cracks after the final immersion. The pre-conditioning test is conducted prior to
the normal reliability test.
SOLDERABILITY TEST
The purpose of this test is to determine the solderability of device package termination
that are intended to be joined to another surface using solder for the attachment. This test
provides optional conditions for aging and solder the purpose of allowing simulation of
the soldering process to use in the device application. It provides procedures for through
hole, axial and surface mount devices. Leads should be dipped at a solder temperature of
245±5C for a duration of 5-10 seconds (per JEDEC Standard 22, Method A102).