What is Orange PCB

Properties of Orange PCB Substrates

The base substrate material used for orange PCBs is typically a standard PCB core like FR-4 fiberglass. What makes the boards orange is the solder mask coating applied over the copper traces. This solder mask is a special orange colored resin.

Some key properties of orange PCB substrates include:

Property Description
Flammability Orange solder mask has UL94 V-0 flammability rating, making it self-extinguishing
Flexibility Flexible orange solder mask available for flex and rigid-flex PCBs
Thermal resistance Withstands lead-free reflow soldering temperatures
Electrical insulation High dielectric strength to prevent shorting between conductors
Hardness Hard and abrasion resistant to protect copper during handling

Orange solder mask maintains these core properties while also providing a distinct cosmetic look. The ability to color the boards orange expands design options.

Comparison to Green Solder Mask

Traditionally, green has been the default color for PCB solder masks. Green solder masks use similar resin formulas but with a green pigment instead of orange.

In terms of performance and durability, there is little difference between green and orange solder masks. They offer comparable:

  • Electrical insulation
  • Flammability ratings
  • Thermal resistance
  • Hardness and scratch resistance

The main difference is simply the color. Choosing between green and orange solder mask is largely an aesthetic preference rather than a functional decision in most cases.

Advantages of Orange PCB Color

So why choose orange color for a PCB over the standard green? Orange PCBs provide some advantages, including:

  1. High visual contrast
  2. Cosmetic appeal for certain products
  3. Counterfeit protection through distinctive color
  4. Potential functional benefits for specific applications

High Visual Contrast

One benefit of orange PCBs is the high visual contrast they provide. The vivid orange color offers strong contrast against white silkscreen, bare copper, and component colors.

This makes orange PCBs easier to inspect visually. Defects like hairline cracks, trace lifting, solder bridges, and foreign object debris stand out more clearly against the orange background compared to green.

The high contrast of orange is especially useful for:

  • Manual visual PCB inspection
  • Optical automated inspection systems
  • Quick identification of different PCB versions

Orange boards catch the eye and highlight important details. This can speed up quality checks and assembly processes.

Cosmetic Appeal

Orange PCBs can also enhance the cosmetic appeal of some consumer products. The bold orange color makes a striking visual impression when used in transparent or partially exposed enclosures.

Typical applications where orange PCBs provide cosmetic benefits include:

  • High-end audio equipment
  • Automotive aftermarket accessories
  • Custom gaming computers
  • Mobile device mods
  • DIY electronics projects

In these products, the vivid orange boards contribute to a distinct aesthetic. Orange PCBs become part of the product’s visual identity and design language.

Counterfeit Protection

Another potential advantage of orange PCBs is counterfeit protection. Consumer electronic devices are common targets for counterfeiting. Fake products may use lower quality components and lack required safety features.

Using orange PCBs helps distinguish genuine OEM boards from generic green fakes. The specific orange color is more difficult to duplicate consistently compared to standard green.

Many prominent electronics brands have adopted orange PCBs in their flagship products for this reason. Examples include:

Brand Products with Orange PCBs
Nintendo Switch and 3DS gaming systems
Apple iPhone smartphones
Samsung Galaxy smartphones
Beats Studio3 headphones

Orange boards serve as a hallmark of authenticity for these top brands. Counterfeiters would need to source matching custom orange PCBs to create convincing fakes.

Potential Functional Benefits

In addition to cosmetic and anti-counterfeiting uses, the orange color of PCBs may provide some functional benefits in certain applications.

One example is PCBs used in outdoor environments. Orange boards may offer better visual contrast against green foliage and earth tones compared to standard green PCBs. This can aid installation and field service.

Orange solder mask also has good resistance to UV light. This helps maintain the boards’ appearance and integrity when exposed to direct sunlight in outdoor use.

Some industries where orange PCBs may provide functional advantages:

  • Solar power inverters
  • Exterior security cameras
  • Outdoor lighting controls
  • Irrigation systems
  • Underwater equipment

The high visibility and UV resistance of orange solder mask benefits PCBs used outdoors and in other harsh environments. However, these advantages are marginal in most applications.

How Orange PCBs Are Manufactured

Orange PCBs are manufactured using the same processes as other PCBs. The main difference is the solder mask coating step.

PCB Fabrication Process Overview

Fabricating a PCB involves several key steps:

  1. Printing the circuit pattern on a copper-clad substrate
  2. Etching away unwanted copper to leave conductive traces
  3. Laminating and drilling the board layers
  4. Plating through holes and vias
  5. Applying solder mask over bare copper
  6. Adding silkscreen legends and symbols

To produce an orange PCB, an orange-pigmented liquid photoimageable (LPI) solder mask is used in step 5 instead of the typical green solder mask.

Applying Orange Solder Mask

Solder mask is a polymer resin applied to the outer layers of a PCB. It coats all areas except the pads and vias that need to remain exposed for soldering components.

LPI solder masks start as a liquid that is coated onto the PCB surface. UV light is then used to selectively cure the solder mask into a hard protective layer.

The key steps in orange solder mask application:

  1. Cleaning copper surface for good adhesion
  2. Applying orange LPI to PCB panel by dip, spray, or curtain coating
  3. Curing orange LPI into B-stage polymer
  4. Aligning photomask or direct imaging to expose solder mask
  5. Developing to remove unexposed solder mask and form openings
  6. Fully curing with UV light and heat to harden orange layer

Precise control of solder mask thickness and registration is critical. Pads must remain cleanly exposed for soldering while mask covers all other areas.

PCB manufacturers source orange LPI solder mask from specialized suppliers. These LPIs are formulated for optimal:

  • Curing and development response
  • Cosmetic finish
  • Adhesion to copper
  • Electrical and thermal performance

Consistent quality of the orange solder mask is key to yielding reliable orange PCBs in volume production.

Design Considerations for Orange PCBs

Designing PCBs with orange solder mask is similar to using green or other colors. A few special considerations can help optimize the cosmetic results.

Solder Mask Clearance

One key factor is solder mask clearance, which is the distance between exposed copper pads/vias and the solder mask opening around them.

For orange solder mask, slightly larger clearances are recommended compared to green:

Pad size Minimum orange solder mask clearance
< 0.5 mm 0.05 mm
0.5-1.0 mm 0.1 mm
> 1.0 mm 0.15 mm

Larger clearances help ensure the bright orange mask doesn’t bleed onto pads and interfere with soldering. It also creates a cleaner visual contrast between pads and the orange background.

Silkscreen Contrast

Silkscreen legends and symbols are typically printed in white ink on orange PCBs. However, the background orange color can make white silkscreen appear slightly muted.

To maximize contrast and readability, use bold fonts and avoid very fine lines or details in silkscreen on orange PCBs. Stick to simple symbols and text.

Black silkscreen offers even higher contrast against orange. However, black ink may not be feasible on some orange PCBs due to the dark pigments interacting with solder mask curing.

Copper Weight and Finish

The copper foil weight and surface finish also impact the appearance of orange PCBs. Some guidelines:

  • Use 1 oz or thicker copper to minimize the visual impact of trace and pad edges
  • Choose a matte surface finish like HASL for a consistent orange color
  • Avoid overly shiny finishes like ENIG that can distort the orange hue

Work with the PCB manufacturer to select copper and finish specs that will give the best cosmetic results with orange solder mask.

Where to Source Orange PCBs

Orange PCBs are available from most full-service PCB manufacturers. However, some suppliers specialize in custom solder mask colors for improved consistency and quality.

Choosing an Orange PCB Supplier

When sourcing orange PCBs, consider suppliers with:

  • Extensive custom solder mask color experience
  • Detailed solder mask specifications and tolerances
  • Rigorous color quality control processes
  • Flexible MOQ and lead time for orange boards

Samples can confirm the supplier’s capability to produce the exact orange hue and finish you need. Review potential suppliers’ quality certifications and standards as well.

Ordering Orange PCBs

To order orange PCBs, specify the following:

  1. Base material and copper weight
  2. Number of layers
  3. Solder mask color (e.g. Pantone 151C Orange)
  4. Surface finish
  5. Solder mask clearances
  6. Silkscreen legend colors
  7. PCB quantity and lead time

Provide the PCB manufacturer with Gerber files or ODB++ data for your design. They can then generate a quote and lead time estimate for your orange PCB order.

Orange PCB Prototype and Production

For new designs, start by ordering a small prototype run of orange PCBs. This allows you to:

  • Verify the orange color meets expectations
  • Test assembly processes and yields
  • Evaluate solder mask durability
  • Inspect for any cosmetic defects

Once the prototypes are approved, proceed with volume production. Communicate any special requirements for orange color consistency and quality control to the supplier.

FAQ

What is the difference between orange and green PCBs?

The main difference is the color of the solder mask. Orange PCBs use an orange-pigmented solder mask while green PCBs use a green-pigmented solder mask. The base PCB material and other properties are typically the same.

Are orange PCBs more expensive than green?

Orange PCBs may cost slightly more than standard green PCBs due to the custom solder mask color. However, the price difference is usually minimal, especially at higher volumes. The orange color does not impact other aspects of PCB fabrication cost.

Can orange solder mask be used on flexible PCBs?

Yes, orange solder mask is available in formulations for rigid and flexible PCBs. Flex and rigid-flex circuits can benefit from the high visual contrast of orange solder mask without compromising flexibility or durability.

Do orange PCBs have any special manufacturing requirements?

Orange PCBs are fabricated using standard processes and equipment. The only difference is the specific orange LPI solder mask used. Work with the PCB manufacturer to select an orange solder mask that is compatible with your base material and surface finish requirements.

What are the most common applications for orange PCBs?

Orange PCBs are commonly used in consumer electronics for cosmetic appeal and counterfeit protection. They are also used in some industrial products for high visual contrast in inspection and outdoor environments. However, orange PCB usage is a small portion of the overall PCB market.