1, screen aging refers to the use of electronic products in the process, with the increase of time and the number of uses, the screen produces brightness decline, contrast reduction, color distortion and other phenomena, thus affecting the user experience. Screen aging will not only affect the user's perception of electronic products, but also may have an adverse effect on human visual health.
2, this phenomenon is mainly manifested as the screen color becomes lighter, the image becomes blurred, the display becomes slow, etc., affecting the use of the product effect and perception. The problem of aging is a problem that cannot be ignored for people who use electronic products for a long time.
3, once the aging of these components is serious, it will cause the hard disk read speed is slow, the hard disk is prone to logical bad sectors, the CD-ROM read disk ability is reduced, and so on. In addition, many slots on the motherboard, such as the gold finger of memory, etc., will also age due to oxidation and other problems.
4, electronic products will age for a long time, which is caused by many environmental factors, such as humidity, dust, temperature, vibration, light, insects and so on. Thus there will be a barrier to use, resulting in failure. Most of the casings in electronic products are plastic products, and aging is inevitable when affected by various environmental factorsMake sure the chip is powered off. The probe touches both pins to check for short or open circuits.
3, for the clock chip test of the fourth-generation Apple motherboard, you first need to connect the chip to the test device. The test device can be a specific test instrument used to provide power to the chip and read the output signal of the chip.
4, the six-pin chip measurement method is as follows: First, the choice of test equipment, the use of digital multimeter or oscilloscope for measurement, to ensure the accuracy of the test. Then, the corresponding pins are tested, and the corresponding functions of each pin are clearly defined against the pin orientation diagram of the six-pin chip.
5For specific products, such as BLE SOC (including eflash, AD/DA, etc.), the Test process is refined into the module TEST shown in Figure 9, including Open/Short Test, DC TEST, Eflash TEST, etc., to ensure functional integrity and standard standards.
Aging chips are often used in vehicle control equipment and semiconductor manufacturing, because these scenarios require very high reliability of the chip. inFatigue testing can detect the reliability and life of the chip, and improve the design and manufacturing process of the chip through the test results.
Aging test: In general aging test, some instruments are powered on for a long time, and the average trouble-free working time is measured, and the fault characteristics of these instruments are analyzed and summarized, and their common problems are found to be solved.
The third is the post-aging stage, which is dedicated to the performance test of the chip after aging test, to determine the aging rate, life and other parameters, so as to evaluate the product quality.
QFN chip package has a smaller size. Compared with traditional packaging forms, QFN chip packages are smaller in size and can achieve higher integration. This is of great significance for today's pursuit of miniaturization and lightweight electronic products. QFN chip package has good heat dissipation performance.
QFN package: QFN (QThe uad Flat No-leads (UAD Flat No-Leads) package is a form of pin-less package that is connected to the circuit board via a pad. It has the characteristics of small size, good heat dissipation performance, and is widely used in mobile phones, wireless equipment and other fields.
This design not only ensures the reliability of welding, but also provides a heat dissipation path, so that the QFN package chip can still run stably in a high temperature environment. With 23 years of experience as a leader in package testing, our QFN test seat is unique.
Has good thermal insulation performance, the top surface of the box is equipped with a blower, with an air duct in the box, so that the hot air in the box has a regular circulation, thereby improving the temperature uniformity in the box. Electric heater sealed tubular shape to prevent direct contact between hot wire and low ignition point gas accidents.
The solderability of components can be tested by holding the component body with stainless steel tweezers and dipping it into a tin pan at 235±5℃ or 230±5℃, 2±0.2s or 3±0.5sTake it out. Check the solder end under a 20-fold microscope, requiring more than 90% solder end of components.
When using the chemical station or oven to handle the chip, be sure to put the chip in the iron dragon crystal boat, do not use plastic boxes. When placing the chip in the quartz boat, if the chip falls on the ground or in the hand, the chip must be cleaned again, and then into the oxidation furnace. Do not touch the inside of the chip box. If it is touched or contaminated by broken chips, it must be cleaned again.
The purpose of sintering is to cure the silver glue, and sintering requires monitoring of the temperature to prevent poor batch quality. General control of sintering temperature of silver glueAt 150℃, sintering time 2 hours. According to the actual situation can be adjusted to 170℃, 1 hour. Insulating glue generally 150℃, 1 hour.
is not conducive to the operation of the post-process. We use a spreader to expand the film of the bonded chip, and the spacing of the LED chip is stretched to about 0.6mm. Manual expansion can also be used, but it is easy to cause bad problems such as chip drop waste. LED dispensing Silver glue or insulating glue is placed on the corresponding position of the LED bracket.