Transparent PCB

Transparent circuit boards in ceramic with a high thermal conductivity

Increase design possibilities with our transparent PCB in ceramic! Not only will it open up a wide range of optical design features and thanks to the favorable material properties of ceramic, these 75-85% transparent printed circuit boards are also highly thermally conductive (26-28 W/mK) and are a strong electrical insulator.

Circuits with single and double-sided layouts are possible using silver metallization (not transparent) as well as adding a glass-based solder mask and a legend/silkscreen layer. We recommend to layout the minimize the solder mask and only design on or around the tracks & pads with instead of covering the full substrate. Even though the solder maks are glass-based, it will decrease the transmissivity by >70%. For best practices, please contact us.

Thanks to these characteristics, the solution is perfect for applications using power LED, laser modules, optical sensors, and circuits where added premium design effects are needed.

Alternatively, we can also supply other sapphire, fused quartz, or borosilicate based PCBs with even higher transparency and copper metalization. Please contact us to discuss.

Advantages transparent ceramic PCB:
  • Transparency up to 80-90%
  • High operating temperature up to 350ºC
  • Low expansion coefficient
  • Strong thermal properties: 26-28 W/mK
  • Limited to no outgassing
  • Hermetic packages possible, 0% water absorption

Download our transparent PCB designrules here:

In case you need further information, more stringent specification or something is unclear;  please contact us.

PropertyITEMSUnitTransparent ceramic
PhysicalTransparency-80%-90%
Material - Alumina%%99.5%
Water absorption%0
ElectricalDielectric Constant (1MHz)-9.8
Dielectric strengthMV/m or KV/mm>16.9
Insulation/Volume resistanceΩ·cm>10^14
MechanicalDensity after Sintering (Bulk density) g/cm33.89
Flexural Strength (3 point)MPA379
Warpage%≦0.3
ThermalCoefficient of Thermal Expansion (CTE)ppm/°C8.4
Thermal Conductivity (25°C)W/m‧K26-28

The data shown is typical of commercially available material and is only offered for comparative purposes. The information shall not to be interpreted as absolute material properties nor does it constitute a representation or warranty for which we assume legal liability. User shall determine suitability of the material for the intended use and assumes all risk and liability whatsoever in connection therewith.

Is this a glass or ceramic substrate?

Our transparent ceramic PCB substrate is a ceramic material. The thermal conductivity is much high then glass but the transmissivity is slightly lower (75-85% rather then 99.5%-99.99% for Quartz).

In case you are looking for lower translucency (higher transparency), we can also supply sapphire & glass PCBs (Borscillate or Quartz). Please contact us and we’ll be happy to discuss the possibilities with you.

What is the impact of the lower translucency compared to glass?

When you look through the substrate, if the object is directly behind it, the image will be very sharp. However, when you start moving away it will become more and more distorted and blurry. We will soon publish pictures to illustrate this.

Do you have data on the transmissivity behavior for different wavelengths? 

Yes, we do. Please enquire.

What are the dimensions and thickness you can manufacture? 

Our standard panels are 4.5″x4.5″ or 115x115mm on which we can usually make circuits up to 4″x4″ or 101x101mm.

Standard thickness is 0.5mm or 0.02″.

Other sizes and thickness might be possible. Please contact us to discuss.

What is the cost of your transparent ceramic?

The unit price is hard to estimate as it depends on the circuit design and panel efficiency. Some designs are a few cents per piece but we also had panels worth close to 100$ with just one circuit on it.

Unfortunately, we cannot manufacture this technology yet at our prototyping line. All orders will be made on the thick film mass production line.

Therefore, note that for this technology, there are startup and tooling costs. We usually estimate 3500-4500 USD to get started and make the first batch with 5-10 panels. After that, there is a 25 panel MOQ for reorders with 1500 USD minimum order value.

Can you make the traces also transparent?

No, we cannot but we advise to design the traces at the minimum width (100-150um) if possible and place them further apart. This allows more light to flow through and create a as transparant circuit as possible.

Is the transmissivity equal at all wavelenghts?

Testing data has showed us that the total transmission of light is stable in the 400-1000nm range. The straight transmission (transparency) will however improve from 40% to 58% in the same spectrum reducing the amount of scattered light significantly. Please refer to the graph below for more information.

Graph: Light transmission % per wavelength

transparent ceramics transmission by wavelength

To learn more about our other ceramic and metal PCB solutions, click on one of the links below:

Contact Us

If you wish to send us an attachment (f.e. drawing/gerber/project brief/…), please use the form on the contact us page.

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