Experiment § How to check if there are bubbles in the hose?
As the electronics industry moves toward a high-precision era, customers' requirements for adhesives in the electronics industry are becoming more and more stringent. Most of the adhesives used in these high-precision products are in hose packaging, which has strict requirements for bubbles and impurities. If the adhesive packaging contains air bubbles, it will cause discontinuous glue disconnection when dispensing. If this situation occurs in the package of the CMOS component, there will be defects such as light leakage or insufficient strength. If there are impurities in the adhesive, the needle may be blocked, and the glue cannot be discharged, causing unnecessary trouble for the customer in production. How to check the bubbles and impurities in the hose? This matter has become a topic that both manufacturers and customers are concerned about. We use the XY table dispenser (Figure 1) to set up a rectangular drawing program (Figure 2) and fill up an entire sheet of A4 paper (Figure 3, the red dots in the upper left corner and the middle are the starting point and at the end, the total length of the line segment is about 830cm). If bubbles in the adhesive or impurities block the needle, the drawn line will discontinue. We randomly check whether the product contains air bubbles according to the number of needles used by the customer and the glue pressure. Similarly, we can also use this program to try many processes and set the vacuum parameters, filter mesh, centrifugal defoaming for each product, etc., to ensure the stability of Everwide's products. What seems to be a simple problem is not easy to do.
─Author: Ms. Zi-hui, Huang
Activity § Education and training of R&D Department
Approximately 5% of Everwide Chemical's working hours are used for training. The most extended history is the education and training of the R&D Department, which takes 30 classes a year from 6 to 9 pm on Wednesday evenings. The content includes polymer knowledge, instrument usage, raw material properties, etc. In addition to listening to lectures, I took a 20-minute test before class to help my colleagues review last week's content in the past two years. The R&D meeting at the end of each month is a project report from each group of colleagues to understand each other's research topics in different groups. People often ask: "Did you listen carefully in class? Do you understand?" The boss always said, "No matter! It's right to go, at least tell God!" After so many years of hard work, he has a solid foundation. Achievement: In addition to the improvement of professional knowledge, we have cultivated several topical experts, and there are about 500 questions in the internal training question bank. Want to know what classes we have this year, what the lecture notes and exam questions look like? Please click the link.
Knowledge § What are the ways to get rid of bubbles?
1. Heating defoaming: using the principle of increasing temperature and decreasing viscosity; for temperature-sensitive, volatile, and thixotropic colloids, heating cannot be used to remove bubbles. 2. Vacuum degassing: using the principle of decreasing pressure and increasing volume, colloids with volatile and anaerobic properties are not suitable for this method. Heating under vacuum, stirring under the vacuum, and other means can usually achieve excellent results. 3. Ultrasonic defoaming: The process of using ultrasonic transmission will cause tremendous pressure on the microscopic surface of the bubble, causing the bubble to burst. The results of past experiments are not very good and may only be suitable for low-viscosity fluids. 4. Single-axis centrifugal deaeration: Use centrifugal force to concentrate the light bubbles on the axis to achieve the purpose of deaeration. For colloids with high thixotropy, air bubbles often stick to the top of the hose; colloids with different specific gravity components should be especially careful to avoid the phenomenon of floating or sinking of the contents. 5. Biaxial centrifugal degassing: The principle is the same as that of uniaxial centrifugal degassing, but the centrifugal object has a specific inclination angle to the axis of the centrifuge; besides the centrifugal object revolving on the axis of the centrifuge, the centrifugal object itself is also one axis rotates. Due to such a design, the biaxial centrifugal degassing has the functions of degassing and stirring. The phenomenon of floating or sinking will not occur in the uniaxial centrifugal degassing. The most significant disadvantage of biaxial centrifugal degassing is that the equipment cost is prohibitive. The processing capacity is small, and the revolution speed is not high enough for some applications.
Living § Travel notes in Russia: Cars
The two cities of Moscow and St. Petersburg are busy. Japanese cars, Korean cars, German cars, American cars are the most common and well-known brands. Why do you rarely see Russian brand cars? The tour guide told us: "Russian cars are of poor quality and they are not cheaper, so few people buy them." Since getting this answer, I deliberately searched for Russian brand cars in St. Petersburg and found about ten LADAs. These cars have no styling at all, and the interior looks quite simple. After returning to Taiwan, I checked the information on the Internet and found that many automobile factories in the Soviet period were closed down, and the rest were invested in foreign shares or technical cooperation in the early 2000s. The automobile industry in the Soviet period was faced with difficulties in the Russian period. The reason is what it is? I think the automobile industry is a complex system, representing an unimaginable general knowledge of production technology, inspection methods, quality standards, management thoughts, business logic, engineering science, various parts manufacturers, etc. This knowledge has already become a solid "system" after long-term cross-border competition and integration in the Western capitalist system. In the group that was closed by communism back then, it was possible to concentrate resources to move cars and survive because of protective barriers. Still, it was impossible to develop an effective "system" in this way. When the market is open, facing a battle-tested opponent (system), it is naturally unable to resist. By the same logic, when taking off and landing at the airport, I did not see any Russian-produced civil aircraft, all of which were Air Bus on the runway. I checked it online and found that out of Aeroflot's 138 civil aircraft, only 9 are made in Russia. I think the reason is still the "system" problem. The "system" tells us: never work behind closed doors.
─Author: Dr. Ming-Xu, Li
