Experiment § Development of epoxy resin for transformer
Recently we have been developing epoxy resins for transformers. Parts such as transformers have high requirements for insulation, and a high silicon dioxide content (about 60%) is added to the resin. And should remove the bubbles in the parts under a high vacuum to obtain a good product.
When we started to send samples, the situation continued, and we managed to overcome them one by one. Unexpectedly, the finished product has not yet started the loop test, and the withstand voltage cannot pass. The customer saw the coil open to see, as shown in Figure 1, nothing abnormal, no bubbles? In Figure 1, the silver-white ones are aluminum blocks, the gold-red ones are thin copper wires, and the black ones are hardened epoxy resin.
Observing the conditions inside the gaps in a low-magnification microscope is challenging. It is impossible to determine whether the tiny gaps between the lines are filled with full resin. However, observing the black epoxy resin, we can see an interesting phenomenon: in each block, the black color in the upper half is lighter, the black color in the lower half is darker, and the surface has a rough feeling. For the convenience of explanation, I mark the color boundaries as shown in Figure 2. This phenomenon is not difficult to understand. During the curing process of the resin, the filler silica will precipitate, which causes the color to look different. Could it be that the silicon dioxide we use is too thick and blocked at the leading edge of the copper wire when it precipitates, making it difficult for the resin to penetrate the crevices of the copper wire, so the insulation is poor? We have halved the particle size of silicon dioxide and have passed the voltage test.
─ Laboratory staff: Ms. Zi-hui, Huang Author: Dr. Ming-xu, Li, Everwide Chemical
Activity § Aluminum Nitride thermal conductive plate
At this year's Taipei International Electronic Industry Technology Exhibition, Everwide Chemical announced a thermally conductive aluminum nitride substrate. Generally, the material of the circuit board is glass fiber composite material, while the circuit board used in LED is mostly aluminum substrate. High-power LED modules require higher thermal conductivity due to extensive heat generation, so ceramic or graphite substrates can achieve high heat dissipation. The aluminum nitride substrates introduced by our company can be regarded as ceramic substrates in terms of materials. However, by simplifying the manufacturing process, the cost and manufacturing time of the substrates can be reduced, which is conducive to the needs of mass production in related industries. In the actual LED module test, the aluminum nitride substrate can indeed achieve the function of heat conduction. SMD LEDs up to 40W can be installed on a 5cm long and 5cm wide substrate. With the heat dissipation module, the working temperature can be controlled below 80°C. In addition, aluminum nitride is an insulating material, and there is no danger of leakage. Its coefficient of thermal expansion is lower than that of metal, and it is better for long-term stability.
─Author: Dr. Ye-xu, Li, Everwide Chemical
Knowledge § How to evaluate whether transparent plastic materials can penetrate UV light?
The simplest method is to take two plastic sheets, drop the UV glue in the middle of the plastic sheets, and expose them under a UV lamp. Whether the UV glue is hardened or not is used to determine whether the material can penetrate the UV light. The digitalization method is to put the plastic sheet on the illuminance meter, expose it under a UV lamp, and use the illuminance meter reading value to obtain the transmittance of the material to a specific wavelength of UV. The academic method puts the plastic sheet on top of the ultraviolet-visible light spectrometer. It scans the transmittance of all wavelengths to determine the suitability and development direction of the UV glue.
Information § The joy of autumn harvest
As the season begins to fall, under the hard work of the farmers, the beautiful hills are full of fruits, and the harvest season has come again. In addition to grapefruit, oranges are another primary agricultural product in Yunlin. To share this sweet fruit with you, after the publication of this newsletter, the top 20 loyal readers who responded, Yongkuan Chemical, will send you a box of delicious and juicy oranges. Thank you, everyone, for your support and care of Everwide Chemical Newsletter, Everwide Chemical; thank you!
The website of Everwide Chemical’s autumn harvest joy activity is: http://0rz.tw/32wSH
Living § Closed two days a week
I remember that before my university, I worked five and a half days a week, that is to say, all days from Monday to Friday, and half a day on Saturday. Later, flexible vacations were implemented, divided into big and small weeks. I remember that the first and third weeks of each month are small weeks, with full-time shifts from Monday to Saturday and vacations on Sunday. The second and four weeks are the prostrations, with full-time work from Monday to Friday and two days off on Saturday and Sunday.
I don't know when it will start. By the Law, there are half-day classes on Saturdays for small weeks and two days off for big week. However, government agencies fully implement a two-day weekly holiday, and the working hours of the two-holiday methods are slightly different. However, no matter how it is calculated, it is an indisputable fact that Taiwan's working hours have declined (the implicit overtime in the name of the responsibility system is not in the discussion). From the perspective of society as a whole, it is, of course, a good thing if efficiency can be improved if working hours decline; but if efficiency does not improve or even lower, it would be wrong. From a historical point of view, the economic basis for the decline in working hours is the hard work of our previous generation. Fresh people in society take it for granted after graduation, and it is dangerous to enjoy this fruit directly. Our next-generation should first prove that they can expand this economic foundation, no matter in terms of work skills or work attitude, and at this time they are suitable to enjoy the leisurely two-day weekly rest.
I feel that Taiwan's industry cannot turn around, and it has something to do with the vacation attitude. The order should be to do things well first and then talk about vacations, but in our social atmosphere, either the standard for doing something well is deficient, or when the time is up, you can directly enjoy the right to vacation.
Because of the outdated attitude towards vacations, we cannot squeeze into the forest of advanced countries.
─Author: Dr. Ming-xu, Li, Everwide Chemical
