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How To Maintain Test Probe

In ICT or FCT test, the probes on the fixture would eventually get dirty after a certain cycles testing, which caused impassable test.

In general, the probes would be fine on spring and force, what brought the test failure result was dirt or flux covering, It caused huge contact resistance between the tip and the test point, which has an impact on the test.

 

We could usually take some effective measurements to control the efficiency of the probe application.

 

1. Create a good test environment

As is well-known, probes are applied to test the print circuit boards. Test probes are in high precision manufacturing. We need to create a clean and dry test environment for In-Circuit Test or Functional Test. The humid environment of many coastal areas like China accelerates the oxidation of the probe. JY Electronics recommends that customers create environment with controlling temperature and humidity for test production line. Furthermore, a dust free room is a necessary and fundamental capacity for high-precision assembly production line.

 


Humidity-control-for-ICT-Test
Dust-free-for-high-precision-assembly-line
Temperature-control-for-ICT-Test

2. Use excellent fixture board

Since JY's many years testing experience, a numerous of probes will be used on the fixtures to test the print circuit boards automatically on the production line quickly. Generally, the fixture probe board made of excellent materials will be helpful to test probe life prolonging. Firstly, the presence of glass fiber( FR4) can be reduced by using good fiber materials. If the fine powder went inside of a probe would cause the reverse action of the spring working. Secondly, the precise drilling holes effect a lot on vertical straightness of test probe, Concentric-circle holes reduces the risk of unilateral side compress during the test process so that extends the probe life.

FR4-fixture-board
Torlon-4203-fixture-board-material

FR4

Torlon 4203

3. Select the appropriate probe tip head

The properly selected probe tip head is also very important for probe maintenance. We occasionally found that some probes perform poorly at this test station, and there were a lot of misdetections during the test, even only last thousands of cycles. Please carefully consider whether the probe tip was selected correctly. We should use the most suitable probe tip head to test the corresponding object. For example, if we used a small 9-point crown head to test a larger solder point, it would increase test failure rate. You can check out JY's advice on how to choose a probe tip, https://www.jyprobe.com/Tips-Selection.html

 

4. Apply the probe’s recommended working stroke

JY has always insisted that our customers use the recommended working travel to test the product, because the probe can maintain the design characteristics and test performance when using the recommended stroke, meanwhile, it can get good test yield. Many customers often use the over-compressed working stroke in order to strengthen the contact effect, which would lead to shortening the probe life cycles and even causing board puncturing out. You can have a look on JY’s recommendation on how to apply working stroke.

https://www.jyprobe.com/How-To-Apply-Working-Stroke.html

 

5. Use high quality soldering paste

Most customers may not consider the option of using a good solder paste, but the quality solder paste will be helpful to the probe life prolonging. Inferior solder paste sometimes has various internal impurities. Impurities may exceed the hardness of the probe tip, which can easily damage the probe tips. High quality solder paste will help the life of the probe relatively.

 

6. Use good soldering molding process

JY serves many customers, and we combined to develop special solder molding process and test probes together that can save a lot time and cost. The soldering molding process seems to be negligible, but it is actually very important. A good solder molding process can reduce a lot of cost for the enterprise, and A good shape of the final formed solder paste point will have a large improvement in test efficiency, similar as goose egg shaped test point will be so easier and more continuable to test than a flat solder pad.


7. Create a suitable probe replacement schedule

JY recommends customers to develop their own probe replacement schedules, replace the probes on the standard lifespan spending. We should know exactly when to maitain our probes and sockets, when to clean probes and check the fixture, also record the things or send the mistake or issues to suppliers for help

 

8. Use alcohol-like cleaning liquid spray probe tips

After a long period of testing, various types of probes will get a lot of dirts and flux. JY recommends you to use special alcohol to clean the probe needle and prolong the use of the probe.

 

9. Ultrasonic wave cleaning

Similarly, JY recommends to use ultrasonic vibration to clean the dirt left on probe tips to prolong the probe life.


10. Choose a soft brush to clean the needle

Please pay attention to choose a soft brush to clean the probe tips. Many customers use a steel wire brush or a hard brush to clean the probe in mistake. Most of the probe needles are plated with gold. The harder wire will damage the gold layer cover of the probe. This will increase oxidation.

 

When routinely maintain test probes, most customers all have own measurements and opearations. JY only provides with some references or suggestions, so that engineers can effectively use the probe to achieve the goal of improving the FPY. Good maintenance methods can usually save a lot of time and money for the fixture houses or ODM,OEM, which can make the test reliable. It is better when we can continue to test the product after a simple maintenance on test probes, but sometimes you find it take a lot time and cost to clean or brush your used probes, please don’t hesitate to replace news probes correctly. We should consider on the other aspects such like use special tip heads, try new working stroke and increase or reduce spring force etc.


Please contact us if you have any question on test issues.

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