Lackwerke Peters GmbH + Co KG, Germany, a 42 year old company engaged in the manufacture and distribution of circuit printing lacquers, entered the Indian market with EMS Technologies of Hyderabad in 2009. Torben Kokernak, applications engineer, Lackwerke Peters, speaks to Dilin Anand of Electronics Bazaar about conformal coatings and casting compounds for PCBs and LED applications.
EB: How important is the Indian market for your company?
We expect an increasing demand for conformal coatings and casting compounds in India due to industrialisation, especially in the automotive industry and in the LED technology sector. India is a fast expanding market and because of the growing requirements for electronic devices, there is bound to be a rise in the need for PCB protection.
EB: What are the different varieties of conformal coating products that your company offers?
We have different products in our conformal coating range, which are sold under the brand name Elpeguard Peters. These products are differentiated based on aspects such as curing. Some of the products are designed only for physical drying, which means only the solvents get evaporated. There are other products that need both physical drying and a reaction with oxygen to form the stable end product. These products can either be dried at room temperature, which takes time, or you can speed up the process by utilising a good ventilated oven. The latter option enables a good supply of oxygen for cross linking. Other methods of drying include using a UV system, in which the first step of drying uses UV-A and UV-C-lights and the second step is of cross linking, which occurs due to the humidity present in the air.
We understand the requirements of different customers like the temperature range and other environmental influences on the electronic product when it is in use. We design our products based on these requirements. Some of our products are more temperature stable, while others are better in withstanding the chemistries of certain attacking agents.
EB: What are the types of conformal coatings used for LED applications?
There are different transparent casting compounds, for example, Wepuran casting resins of the series VT 3402 KK, clear conformal coatings like ELPEGUARD SL 1407 FLZ (in spray cans) or conformal coatings of the series ELPEGUARD SL 1307 FLZ. These are used for protecting LED applications against environmental influences like moisture, dust and chemicals.
EB: What are the different methods by which these coatings are applied?
A conformal coating is the last step in the process of manufacturing a PCB. It covers the circuit board to protect it from environmental influences like temperature, salt, fog, dust and chemicals. Without this coating, the electronic circuitry would be susceptible to attack, and hence, become faulty or damaged.
There are a lot of different ways in which these coatings can be applied. For instance, some would use a brush for low volumes while others spray the coating on top of the circuitry by using spray guns or selective coating machines. Some customers also dip the PCBs in the conformal coating. Selective coating machines or the dip coating process is preferred for large volume batches because these processes are more accurate and much faster.
EB: What is selective coating used for, and do you manufacture the machines that do it?
Selective coating is used when the assembled PCBs that have to be coated have lots of very precise circuitry and connectors on them. To ensure that liquids do not flow into the connectors, manufacturers use this process to coat a very precise and accurate line of coating.
We do not manufacture these coating machines ourselves, but we work very closely with those who do. When we meet the customer, we work with these selective coating machine producers and prepare test boards to help the customer decide the right combination of the machine and the conformal coating.
EB: What is unique about Lackwerke Peters as compared to other companies that deal with lacquers?
We are the only company that produces lacquers that are used for manufacturing PCBs and for protecting them. We have competitors for lacquers that are used in PCB manufacture like etch resists, solder masks, carbon inks, and heat sink pastes. We also have different competitors for lacquers used in protecting assembled PCBs. But we are the only company who can do both, and so we are a single point contact for both producing and protection. Moreover, our products offer very high durability, and are able to withstand harsh temperatures and the adverse conditions inside aircrafts or when exposed to salt, fog, etc.
We are also the only manufacturer of coloured conformal coatings. A black conformal coating in the background allows you to spot LEDs easily, while a white conformal coating gives a unique reflective background. Both also help to protect the identity of the components used.
EB: Could you elaborate on the products in your R&D pipeline?
Our current focus is on lacquer systems for lighting electronics like LED drivers. We are developing special clear and transparent coatings, which allow better performance. We also design white solder masks that are very stable against yellowing, which happens due to exposure to high temperatures or UV rays.
EB: What are you doing to establish your brand in India?
With our partner Sanjay Parmar, we have set up a competent nationwide service and distribution network in India. We will intensify our efforts in India with our competent service and the support of our applications engineers from Germany. With our global OEM management, we provide very interesting contacts and synergies to our Indian customers so that we mutually benefit. India is one of our top priority markets.
