Pulse Electronics provides electronic component design and manufacturing. It offers a catalog of products as well as custom capabilities, supplying electronic components to OEMs, contract manufacturers and consumer electronic manufacturers. The company is now private but was formerly listed on the NYSE. It has annual sales of approximately $400 million. The company makes about 5% of all the antennas made for smart phones, routers and other consumer electronics wireless equipment. This activity was gained through acquisition including parts of Nokia's antenna business. It has now developed equipment, known as "fluidANT" that can print antennas on 3D substrates.
The majority of antennas are made by etching, either on the PCB with the other core components or on a separate 2D surface integrated with the other electronics. This is cost effective and mature. However, increasingly as phones become thinner and smaller OEMs are exploring making antennas on the surface of the device itself. This has the additional benefit that a UHF antenna (operating in hundreds of MHz to GHz range) can perform better when occupying 3 dimensions rather than two.
The most common way to make 3D antennas on the device substrate is by Laser Direct Structuring (LDS) - accounting for about a third of 3D antennas, with alternative options being stamped foil and flexible substrate antennas conformed to the device substrate. However, substrates suitable for LDS are limited in choice, are brittle and expensive.
Pulse Electronics developed FluidANT to enable OEMs to overcome the limitation of substrates that are compatible with LDS and allow them to use other substrates which can be cheaper or enable new finishes (texture etc) such as polycarbonates, polyamide, ABS etc. It also allows for more color options because some color casings may contain more carbon than others which needs to be countered for in the antenna design (such as black cases).
The FluidANT machine jets micron-sized silver flake based ink onto the device casing from a print head mounted on a 6 axis robot arm with 1 rotation axis - allowing it to print around objects. Each layer is 25 microns deep and 400 microns wide -optimised for skin depth to provide a good antenna. Narrower heads are available for other applications. The printed ink is then cured at 100 to 110 Degrees Celsius in most cases - in some cases a lower temperature is used depending on the substrate (such as polyamide - 80 Degrees Celsius).
Additionally, the printed ink is suitable for reflow soldering so strong galvanic connections can be made with connecting components.
The company collaborates with major ink manufacturers to develop targeted inks for its specific applications. It provides a range of ink options which can be used for different applications and materials.
The company has used this process to make more than 2 million antennas which are used in commercial devices today.
Each antenna can take as little as 6-8 seconds to print depending on type, frequency and scope. LDS laser patterning is faster than this, but then the patterned device need to be plated which may occur in a different location and is done as a batch process which increases prototype time and adds supply chain steps in production.
John Graham, VP &GM of the Printer Business Unit at Pulse Electronics, cites one of the big advantages of FluidANT is the digital nature of the process - more and more consumer electronics applications are emerging and each need customized antennas. The FluidANT process helps the industry accelerate product development, use a wider range of materials and industrial designs and produce highly consistent RF products. The digital process also enables quick production changes and help operations in the total cost of solution ownership.
While Pulse Electronics will continue to use FluidANT to make antennas, the company intend to sell the equipment to others to allow them to make it themselves, which will help to contract the manufacturing value chain. The current equipment costs $160,000 but can reach $100,000. Pulse Electronics will provide the formulated inks, but in high volume expect that the inks will be purchased direct from the ink manufacturer.
The company is also looking at other applications for printing conductive inks on 3D surfaces but starting off with the known market of antennas where they see the need and have existing knowledge.
For more information see www.fluidant.com
Top image: FluidANT