Electroless plating is a popular method in manufacturing printed circuits or flexible circuits.

The electroless plating concept is not new and is used to protect conductors against oxidation. However, it is not the default process for printed circuit manufacturing. Many of circuit manufacturers do not have in- house plating capabilities and rely on plating shops for surface finishing.

Over the past decade there has been remarkable progress with electroless plating. Nowadays, material suppliers have many new chemicals available for plating processes, especially for surface treatment. Chemical suppliers are confident that printed circuit manufacturers can secure metallizing on plastic substrates without a large investment.

I participated in R&D projects during the 1990s where we tried to produce flexible copper laminates without adhesive layers. Manufacturers employed different processes such as casting and sputtering to generate new laminates. The combination of electroless plating and electrical plating was considered a candidate because it called for very little investment. Unfortunately, the chemical plating processes could not provide a secure enough bond strength between the base film and copper conductors and was not worth pursuing.

New plating chemicals are available to use with the plating process and provide a reliable bond strength with flexible laminates. However, plating shops do not follow the recipe line by line, and create their own process conditions by adding supplemental treatments to increase the cost performance. Usually, the chemical costs are significant.

Material suppliers have an advantage from electroless plating – they can experiment with new laminates using base materials other than polyimide films or PET films at a significantly lower cost. The plating process could be available for other materials such as rubber sheets, cloths and papers.

Let’s not forget the biggest advantage with electroless plating is the metallization of the nonconductive surface of plastic materials. This could be the key process from the semiadditive process to generate ultra-fine traces in high density flexible circuits. The process is very simple – just dip flexible items in the plating bathes few minutes -- that’s it!

In my opinion, electroless plating is the key to build high-density flexible circuits, but it is not easy to create stable plating conditions. Experiments in trial-and-error activities are necessary to create these conditions. You could consider the process condition and handling as intellectual property owned by the manufacturer.

If you are interested in learning more about electroless plating, feel free to contact DKN Research with any questions or comments.

Dominique K. Numakura, This email address is being protected from spambots. You need JavaScript enabled to view it.

DKN Research, www.dknresearch.com

DKN Research Newsletter #1928, October 13, 2019 (English Edition)(Micro Electronics & Packaging) This email address is being protected from spambots. You need JavaScript enabled to view it.

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Headlines of the Week

1. Asahi Kasei Electronics (Device manufacturer in Japan) rolled out a small-size 3-D magnetic smart switch “AK09970D” for wearable devices with 1.35mm2 WL-CSP package.

2. Toshiba (Major electric & electronics company in Japan) changed the name of Toshiba Memory to “KIOXIA”. New logo and corporate color, silver were released. Kioku means memory by Japanese.

3. Mitsubishi Electric (Major electric & electronics company in Japan) developed a trench type SiC-MOSFET with the lowest resistance rate of 1.84 milliohm/cm2 for the power devices of home & industrial appliances.

4. Tokyo University (Japan) developed a cooling device utilizing thermionic cooling effects of hetero structure GaAs/AlxzGaxAs instead of Peltier cooling devices.

5. TDK (Major component supplier in Japan) will display seven categories of products at CEATE 2019. They are IoT, Mobility, Wellness, Connection, Energy, Robotics and Experience.

6. NICT (Major R&D organization in Japan) was successful for 1 petabit switching per second with collaboration of multi core optical fiver and fundamental optical network.

7. NTT Docomo (Cellular phone carrier in Japan) as started 4G LTE Service with glass antennas developed with AGC, major glass product supplier in Japan.

8. Murata (Major component supplier in Japan) built two new manufacturing plants in Thailand to expand the production capacity of EMI filters and antenna coils for mobile products.

9. Renesas (Major semiconductor manufacturer in Japan) unveiled the new Arm 32 bit microprocessor series RA Family Series for IoT systems.

10. Kioxia (Major semiconductor manufacturer in Japan, ex Toshiba) completed building of the first plant in Iwate Prefecture. It will start the production of 3-D NAND flash memory in 2020.

11. YDB (Market research company in Japan) forecast the market of automobiles displays 201.98 million units in 2023 from 166.46 million units in 2018.

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