Today, xiaobian will bring you about the semiconductor device screening scheme design introduction, we quickly look ~ semiconductor devices can be divided into discrete devices and integrated circuits two categories. Discrete devices include all kinds of diodes, triodes, field-effect tubes, SCR, photoelectric devices and special devices; Integrated circuit includes bipolar circuit, MOS circuit, thick film circuit, thin film circuit and other devices.
The failure modes and failure mechanisms of various devices are different. Different failure mechanisms should be used for different screening items, such as looking for defects such as poor welding and unstable installation, vibration acceleration can be used; Find components bonding is not firm, bad mounting, internal lead configuration is not appropriate and other defects, using centrifugal acceleration; Find intermittent short circuit, intermittent open circuit and other defects, the use of mechanical impact.
Therefore, the screening procedures for different devices may not be the same. For example, the main failure modes of transistors are short circuit, open circuit, intermittent operation, parameter degradation and mechanical defects, and each failure mode involves a variety of failure mechanisms, which is an important basis for formulating reasonable screening procedures.
① Appearance inspection: use 10 times magnifying glass to check the appearance, lead and material for defects.
(2) Temperature cycle: the components are alternately exposed to the specified limit high temperature and limit low temperature, and continuously subjected to the specified conditions and the specified number of cycles. The total transfer time from cold to hot or from hot to cold shall not exceed 1min, and the retention time shall not be less than 10min.
(3) High temperature life (non-working) : in accordance with the life test requirements specified in national standards, so that the components in the specified environmental conditions (usually the highest temperature) storage specified time.
(4) Electric power aging: according to derating conditions to achieve the purpose of aging under the highest junction temperature, aging power is selected according to the conditions specified by the components.
Sealing test: cavity components, first fine leak detection, then coarse leak detection.
⑥ Electrical parameter test (including voltage or leakage current test) : according to the product technical specifications contract provisions.
Function test: according to the product technical specification contract provisions.
Based on the above principles, the test and screening order of components was optimized. According to the classification of failure modes, the test and screening means were sorted according to the principle of test and screening order of components.
Diode typical filter program
Commonly used semiconductor diodes are rectifier, switch, regulator, detection and double base type, typical screening procedures are as follows:
(1) high temperature storage: germanium tube 100℃, silicon tube 150℃, 96h.
(2) Temperature cycle: germanium tube -55℃-+85℃,5 times; Silicon tube -55℃~+125℃,5 times.
(3) Knock change: knock 3~5 times with hard rubber hammer, and monitor the positive characteristic curve with graph instrument.
(4) Fall: at a height of 80cm, press free fall to the glass plate 5 ~ 15 times.
(5) Power aging:
① Switch tube :1.5 times rated forward current, 12 hours;
② Regulator tube :1 ~ 1.5 times rated power, 12 hours;
Detection rectifier tube :1 ~ 1.5 times the rated current, 12 hours;
Double base diode: rated power aging 12 hours.
(6) High temperature deviation: germanium tube 700C, silicon tube 1250C, rated reverse voltage 2 hours, leakage current does not exceed the standard value.
(7) High temperature test: germanium tube 70℃, silicon tube 125℃.
(8) Low temperature test :-55℃.
(9) Appearance inspection: use a microscope or magnifying glass to check the appearance quality and remove defective pipes such as broken glass.
Triode typical screening procedures
High temperature storage - temperature cycle - drop (not done for high-power pipes) - power aging - high and low temperature test (done when required) - normal temperature test - thickness leak detection - appearance inspection.
(1) High temperature storage: germanium tube 100℃, silicon tube 175℃, 96 hours.
(2) Power aging: the small power tube is added to the junction temperature Tjm and aged for 24 hours. The high frequency tube should pay attention to eliminating harmful high frequency oscillation, so as not to degrade the tube hFE.
Semiconductor integrated circuit typical screening procedures
High temperature storage -- temperature cycle -- (drop) -- centrifugal -- high temperature power aging -- high temperature test -- low temperature test -- leak detection -- appearance inspection -- normal temperature test.
(1) High temperature storage :85 ~ 175℃, 96 hours.
(2) Centrifugation :20000g,1 minute
(3) High temperature power aging :85℃, 96 hours, under rated voltage, rated load dynamic aging.
The screening of electronic components should focus on reliability screening, and the specific screening procedures can be flexibly formulated according to the structural characteristics, failure modes and use requirements of components.
Screening and quality control are important links in the production of highly reliable components. For high quality products, the whole batch of products can achieve its inherent high reliability through screening. For inferior products, due to their inherent defects, it is impossible to screen out highly reliable products. Therefore, it is necessary to evaluate the quality and reliability level of the product by sampling test before screening, and it is helpful to formulate a reasonable screening procedure through test and failure analysis.