With the increasing application of integrated circuit electronic products, the natural environment they face has become quite complex, which increases the probability of electronic component failures. When faulty components are ready for replacement or problems are discovered, the name and model of integrated circuit components become very important identification marks. Therefore, the quality of device printing marks can also affect the stability of electronic products and even the entire system. Ensuring the integrity of printing marks has become a key issue in various complex climate conditions.

 

2 Testing and Results
There are usually two printing methods for devices: laser printing and ink printing: ink printing is the process of using glass ink (or silver compounds, etc.) to print device markings on the casing. Laser printing is the process of using a laser machine to print equipment markings on ceramic shells. Although the handwriting of laser printing is permanent, it is not clear enough to be easily recognized without ink printing, and laser printing requires specialized equipment. Due to high costs, ink printing for equipment markings is usually used on ceramic shells. Based on the climatic conditions under which the equipment is used, we have selected alternating humidity and heat test, salt spray test, and solvent resistance test to test the equipment, in order to understand and improve the stability and firmness of the equipment markings under these test conditions.

2.1 Experimental methods and conditions 
Alternating humidity and heat test: certain conditions: number of cycles: 10 times, each time for 24 hours.
Salt spray test: Salt solution concentration: 2.0%; Temperature: 35 ℃, time: 24 hours; Precipitation rate: 30000mg/m2/24h.
Solvent resistance test: Temperature: 65 ℃~70 ℃; A mixture of 42 volumes of deionized water, 1 volume of ether, and 1 volume of ethanolamine; Soak the device for 2 minutes and brush forward 10 times.
We selected 60 ink printing devices and 60 laser printing devices and evenly divided them into 3 groups. Based on the above conditions, we conducted a wet heat alternation test. The results of the salt spray test and solvent resistance test are shown in Table 1.

2.2 Fault Symptoms
2.2.1 Solvent resistance test
In devices printed with ink, most of the markings on two devices have fallen off. One of the devices has a blurry label and cannot recognize the identification of these three devices; The markings of 20 laser printed devices can be clearly identified.

2.2.2 Alternating Damp Heat Test
It can clearly identify the markings of 20 devices printed with ink and 20 devices printed with laser.

2.2.3 Salt spray test
The device printed with ink has 6 markings, most of which are detached and have corrosion points. The two small parts of the mark are detached and difficult to identify, while the overall mark exists but is blurred. For laser printing equipment, all seven are incomplete due to corrosion on the cover plate.
Failure Mechanisms and Analysis of Three Devices
Ink printing is the process of using ink as a mark on the cover plate, and then baking it at high temperature for a certain period of time to solidify the ink on the cover plate, as a mark for equipment recognition. Laser printing uses the cover plate of a laser beam printing device. The depth of laser printing on the cover plate is less than the thickness of its surface protective metal coating, which will not damage the surface of the equipment. The following is an analysis of the failure phenomenon based on several experimental mechanisms.

3.1 Solvent resistance test
The solvent resistance test is to place chemical reagents in a container at a certain temperature, and then immerse the equipment in the container for a period of time (the chemical solution should cover the entire equipment). Rub the markings on the surface of the equipment with tools as needed to see if there are any signs of malfunction.
In the experiment, the labeling of three devices printed with ink failed because the reagents used in the experiment were organic solvents, and the ink was also composed of organic substances. When the device is immersed in the corresponding solution and temperature, the ink does not cure properly, or there are some stains or impurities between the ink and the cover plate due to the unclean surface of the cover plate. When there is external force or solution, due to its instability, it may move or undergo chemical reactions, resulting in the label falling off. Organic solvents usually cannot dissolve metal substances, while laser printing is carried out on metal surfaces and does not contain organic components. Therefore, chemical reagents cannot change the marking after laser printing equipment, which means that solvent resistance testing will not affect laser printing.

3.2 Alternating Damp Heat Test
This test involves placing the device at a certain temperature and humidity to withstand changes in temperature and humidity. When the temperature in the testing equipment is lower than the temperature of the equipment, condensation occurs. If the printing marks are not firm, they will become fragile or even fall off due to the disappearance of condensed matter; During the experiment, water molecules may penetrate due to changes in temperature and humidity. In this case, if the printing marks are not firm or there are many impurities on the surface of the cover plate during the printing process, water molecules can easily penetrate between the marks and the cover plate