We are excited to share a glimpse of our latest turnkey project — double-sided fully assembled transparent FPC with FR4 stiffeners and micro-components! Our customer is satisfied with this project and generously talks us about sharing his stunning transparent PCB online.
High-Precision Transparent PCB with Micro-SMT Assembly
At PCBONLINE, we've just completed a masterpiece in flexible PCB fabrication and assembly. Seeing is believing. Please check the 6-up transparent flexible panel.
It contains:
- 3 fully assembled FPCs mounted with ultra-fine chips, connectors, and passive components on both sides,
- 1 single-sided assembled FPC (the bottom side is assembled),
- and 2 bare FPCs.
What is special about our advanced PCB showcase made by PCBONLINE? You may ask.
First of all, the PCB is transparent and flexible, with a transparency of 95%.
The laminate material is PET with 95% transparency. From the 6-up panel, you can see the transparent edge rails that take up the most area of the panel. That is the PET. The real FPCs are the 6 long strips — their copper circuit traces/pads, FR4 stiffeners, and components are visible.
Second, the transparent FPCs are double-layer with dual-component mounting sides.
Here's the thing: most transparent PCBs are only single-layer. However, the transparent FPC showcase we made has more complex circuits and provides more space for high-density SMT.
In fact, PCBONLINE has pushed the limit of transparent PCBs to four-layer transparent FPCs with dual-side component mounting.
Third, our transparent FPCs have micro SMD components assembled on both sides.
The components are all micro. The connector has a height of only 0.82mm and a pitch of 0.2mm. The passive components are 0201 and 01005. Among the chips mounted on the transparent FPC, the smallest size is 2.5mm x 2.5mm.
Seeing is believing. This project is a testament to how PCBONLINE excels in micro-SMT precision.
Last, the transparent FPC has multiple FR4 stiffeners, which are thin yet offer robust strength.
The FR4 stiffeners to provide mechanical strength have a thickness of 0.15mm. They are on the corners and in the areas for component mounting.
You should know that the thinner the FR4, the more difficult it is to control the thickness tolerance. We made the tolerance for FR4 stiffeners of ±0.03mm, which is crucial for the precise fit of the connector.
This transparent FPC project is a masterpiece of transparent aesthetics, flexibility, and ultra-precision SMT assembly.
At PCBONLINE, we have turnkey manufacturing capabilities to meet transparency and precision demands, offering you stunning, reliable transparent PCBs.
By precise positioning, via drilling and plating on the PET film in our two advanced PCB manufacturing bases, and fully automatic SMT assembly at our turnkey PCB assembly factory, we fabricate and assemble the two-layer transparent FPCs meeting our customers' requirements.
New to Transparent Flexible PCBs? Here's What You Need to Know
If you're seeing a transparent FPC for the first time, you might wonder: How is it clear, and where are the wires? Unlike FR4 PCBs or typical yellow Polyimide (PI) flexible circuits, transparent FPCs usually use PET. Only in a few applications is Colorless Polyimide (CPI) used as the substrate material.
In fact, 95% of transparent FPCs are PET flexible PCBs. CPI is an expensive material, and CPI transparent flexible PCBs are only used in high-end smartphone foldable screens and aerospace flexible circuits.
PET provides transparency of 90% and above, while CPI is not really colorless but has a little yellowness. Nevertheless, CPI is extremely expensive.
PET transparency PCBs often use low-temperature solder paste (135℃ - 150℃) for surface mounting components.
How do we fabricate transparent PCBs?
If the circuit is simple in a single layer, the fabrication method is printing silver paste onto the PET film for conductivity. The line width is thick.
If the circuit is fine and requires mounting microchips, the fabrication method is to apply the copper foil onto the PET film and then etch the ultra-thin copper foil.
In our transparent FPC project, we used the second fabrication method. You can see that we can mount multiple chips, passive components, and a connector on a PET transparent PCB reliably.
Do you have concerns about the flexibility of PET transparent FPC? Well, most transparent PCBs are flex-to-install for once, without the dynamic folding requirements like foldable screens. So in most cases, the fatigue resistance of PEY is more than sufficient.
Why choose transparent FPCs? You may ask.
Choosing transparent PCBs is usually for the visual effect. A transparent FPC offers these advantages:
- High light transmittance: PET FPCs can provide transparency up to 97%. They are ideal for applications requiring optical clarity, such as LED displays, smart wearables, and medical devices.
- Aesthetic appeal: They allow designers to showcase the internal "skeleton" of the electronics, creating a high-tech, futuristic look.
- Space-saving & lightweight: Like all FPCs, transparent FPCs can be folded or bent, but the transparency adds an extra dimension of design freedom.
One-Stop Transparent PCB Manufacturer PCBONLINE
The one-stop PCB manufacturer, PCBONLINE, founded in 2005, provides transparent PCB manufacturing and assembly to customers around the world. Industries we serve include automotive, defense, industrial, medical, communications, and consumer electronics.
By ordering transparent PCBs from PCBONLINE, you will enjoy these benefits:
- One-stop transparent PCB fabrication and assembly, including PET FPCs, CPI FPCs, and glass PCBs.
- PCBONLINE's CAM engineer will provide one-on-one engineering support to assist you with the best practices.
- PCBONLINE always manages to reduce your costs with the latest technologies and manufacturing optimization.
- We push the limit of PET transparent PCBs to four layers and dual component-mounting sides.
- High-quality transparent PCB manufacturing and assembly, certified with 9001:2015, ISO 14001:2015, IATF 16949:2016, RoHS, REACH, UL, and IPC-A-610 Class 2/3.
PCBONLINE has provided turnkey transparent PCBs to many satisfied customers, including Fortune 500 companies. If your transparent PCB order amount is $5000 or more, we will provide you with free functional testing.
Conclusion
Typically, transparent PCBs are simple and single-sided. However, as shown in our latest showcase, we've mastered the art of Double-Sided Transparent FPCs with precision SMT assembly. By using ultra-thin copper foils and precision etching, we maintain high transparency while supporting dual-side SMT assembly and FR4 stiffeners for maximum durability. If you have any questions about transparent PCBs, or you want to transparent PCB turnkey services, contact PCBONLINE by email at info@pcbonline.com.
PCB assembly at PCBONLINE.pdf
PCB fabrication at PCBONLINE.pdf
