Precision PCB Fabrication, High-Frequency PCB, High-Speed PCB, Standard PCB, Multilayer PCB and PCB Assembly.
The most reliable PCB & PCBA custom service factory.
Circuit board burn-in test method and general tutorial
Circuit board burn-in test method and general tutorial
The concept of PCB aging
The PCB aging we usually say is that after the circuit board is energized and worked for a certain period of time under certain conditions, some component parameters on the circuit board will change. This change is related to the time the circuit board is used. This is for some special purposes. Circuit boards are absolutely not allowed, so many circuit boards will be treated with anti-aging treatment before they leave the factory to stabilize the circuit before use. In this way, reliability and safety can be greatly improved.
PCB aging test method
In general industrial refrigerators, a single piece of non-welded parts is used in a fixed manner, and the temperature generally changes alternately between -40°C and +55°C. During this process, the lower temperature should be maintained for 1 hour, and then Slowly return to room temperature, keep it for 4 hours if it is not at room temperature, and then slowly increase the temperature after 4 hours to reach the highest setting temperature. This state should also be maintained for 2 hours, and then slowly fall to room temperature. At this time, it should also be maintained 2 hours, take it out, check the smallest line and cut the health condition with vias. This process requires two cycles to be more assured.
General Regulations for Aging of Instrumentation Circuit Boards
The following circuit board manufacturers introduce a general procedure for the aging of instrumentation circuit boards. This procedure needs to be divided into several aspects, including:
1. Subject content and scope of application
2. Definition
3. Purpose
4. Detect environmental conditions
5. Requirements before aging
6. Aging equipment
7. Aging
8. Recovery
9. Final inspection
Let’s talk about these nine points separately.
Subject content and scope of application
This standard specifies the basic content and requirements for the aging screening of instrumentation functional circuit boards. This standard applies to the aging screening of various single-loop regulators and functional circuit boards of various digital instruments in the instrumentation industry.
definition
The instrumentation function circuit board (hereinafter referred to as the function board) refers to the printed circuit board that has installed components or components in the instrumentation and can complete certain functions.
Purpose
Make the functional board in a thermal aging equipment with temperature changes, subject to changes in air temperature, through the combined effects of high temperature, low temperature, high and low temperature changes and electrical power, and expose the defects of the functional board, such as poor welding, component parameter mismatch, and temperature. The faults caused during drift and debugging can be eliminated, which will stabilize the parameters of the non-defective function board.
Detect environmental conditions
The test should be carried out under the following environmental conditions: Temperature: 15~35 degree Celsius Relative humidity: 45%~75% Atmospheric pressure: 86~106Kpa
Requirements before aging
There are also two requirements for the old circuit board. The two requirements are:
1. Electrical parameter testing All functional boards to be aging need to be tested for electrical parameters, and functional boards whose parameters do not meet the requirements should be eliminated.
2. Appearance inspection All functional boards to be aging need to be visually inspected first. For functional boards with obvious defects, such as short-circuit, open circuit, component installation errors, missing parts, and other defective functional boards should be eliminated.
Aging equipment
Any point in the working space of the heat aging equipment should meet the following requirements:
1. It can maintain the low temperature required for thermal aging.
2. It can maintain the high temperature required for thermal aging.
3. The change process from high temperature to low temperature or from low temperature to high temperature can be carried out according to the temperature change rate required for aging.
Function board installation and support
1. The function board should be installed on the bracket in the normal use position.
2. The support of the functional board should be insulated to ensure that there is no leakage between the tested functional board and the support.
3. The heat conduction of the support of the functional board should be low, so that the functional board and the support are actually insulated.
Electric power aging equipment
1. Electrical power aging equipment should ensure that it should not be shut down midway due to aging equipment during the aging process.
2. The electrical power aging equipment should ensure that it provides the voltage and current required by the aging function board, and can provide a variable input signal, and can detect each functional partner at any time.
Ageing
heat aging conditions
1. The heat aging time is at least 72h.
2. If there are no other regulations, the temperature cycle range should be: 0~60 degree Celsius or ~10~60 degree Celsius, which can be selected by yourself.
3. Temperature change rate (average value during the change from low temperature to high temperature or from high temperature to low temperature) 1±0.5°C/min.
Aging method
The aging method is generally divided into seven steps. The seven steps are:
1. Put the functional board at ambient temperature into the heat aging equipment at the same temperature.
2. The function board is running.
3. Then the temperature in the equipment should be reduced to room temperature at a prescribed rate.
4. Then the temperature in the equipment should rise to the specified temperature at a specified rate.
5. Then the temperature in the equipment should be reduced to the specified temperature value at a specified rate.
6. After the temperature in the equipment reaches a stable level, the functional board should be exposed to high temperature for 2 hours.
7. When the temperature in the equipment reaches a stable level, the functional board should be exposed to low temperature for 2h.
8. Repeat 3 to 7 consecutively. Until the specified aging time, and according to the specified aging time, the function board is measured and recorded once.
9. The function board should be taken out of the box after the temperature in the equipment reaches room temperature and is stable.
recover
After the functional board is taken out, it should be placed under the specified conditions and allowed to reach a stable temperature, and the recovery time should be at least 1h.
final inspection
Perform electrical parameter testing on the functional board under specified conditions, and reject those that do not meet the requirements.
Through the above nine steps, under normal circumstances, it is possible to do a good job in the detection of the aging of the circuit board, but some special cases are still to be excluded, which requires everyone to learn to learn and use.
iPCB is a high-tech manufacturing enterprise focusing on the development and production of high-precision PCBs. iPCB is happy to be your business partner. Our business goal is to become the most professional prototyping PCB manufacturer in the world. Mainly focus on microwave high frequency PCB, high frequency mixed pressure, ultra-high multi-layer IC testing, from 1+ to 6+ HDI, Anylayer HDI, IC Substrate, IC test board,rigid flexible PCB, ordinary multi-layer FR4 PCB, etc. Products are widely used in industry 4.0, communications, industrial control, digital, power, computers, automobiles, medical, aerospace, instrumentation, Internet of Things and other fields.
