What is the best color for PCB? Generally speaking, green is the best choice for PCB. On the one hand, green solder mask ink is cheap, in sufficient supply, mature in production process, with low scrap rate and obvious cost advantage; on the other hand, it has a sharp contrast with white silk-screen text, which is convenient for seeing circuits and components during assembly and maintenance, and is also environmentally friendly.
What is the standard color of PCB?
In the PCB industry, green is generally regarded as the standard color. This is mainly because:
- The process is mature and the cost is low: The green solder mask process is the most mature and simple, and the use of green solder mask ink is cost-effective. Most manufacturers use the same green ink, which can reduce the cost of line change and is more economical in large-scale production.
- Good visibility and recognition: The green and white printed text form a sharp contrast, which is convenient for assemblers to scan the circuit board, less stress on the eyes, and good visual contrast when checking welding quality and circuit layout. The visual effect is good in the yellow light room, and the instrument recognition effect for optical positioning and calibration is also better.
- Relatively safe and environmentally friendly: Compared with other colors such as blue and black, green solder resist does not contain elements such as cobalt and carbon, has a low risk of short circuit when powered on, and generally does not release toxic gases in high temperature environments.
Which PCB color is best?
The choice of PCB color depends on the specific application requirements and environmental conditions. PCBs of different colors have their own characteristics and applicable scenarios:
- Green PCB: It is the most common color. It is low-cost and has obvious advantages in large-scale production; it is easy to develop and it is easier to remove unnecessary parts during the production process; it has good visual effects and is eye-friendly, which helps the visual contrast of high-brightness metal pads and logos, and is conducive to optical positioning calibration; it also has a certain degree of confidentiality and is relatively safe and environmentally friendly.
- Black PCB: It gives people a high-end and mysterious feeling and is often used in high-end audio equipment, gaming hardware, etc. The contrast of the words marking the welding parts is high, and the colored connectors are more conspicuous against a black background, and the visual effect is good when placed in the chassis. However, the production process of black PCB has high process requirements, which is easy to cause color difference, resulting in an increase in defective rate, and the circuit routing is difficult to identify, which will increase the difficulty of maintenance and debugging in the R&D and after-sales stages.
- Blue PCB: It can provide novel and high-end visual effects, suitable for electronic products that pursue product appearance differentiation, with good screen printing contrast, relatively simple production process and moderate cost.
- Red PCB: It has excellent visibility, can clearly define the contrast of traces, planes and blank areas, and has beautiful screen printing effects. It usually uses high-temperature resistant red photosensitive dyes, has good thermal stability and weather resistance, and is often used in specific applications such as high-end communication equipment and military electronics, but the production process is complex and the cost is high.
- White PCB: The appearance is clean and beautiful, suitable for products with high decorativeness, such as high-end headphones, watches, etc. However, it is easy to hide the routing, the production cost is relatively high, and the welding test is relatively difficult.
Does PCB color matter?
PCB color is important to a certain extent.
From the perspective of manufacturing, color is related to production process. The production process of green PCB is the most mature and the cost is relatively low. Because green solder mask ink is more commonly used, manufacturers can use equipment and materials more efficiently and reduce production costs during large-scale production.
Black PCBs have higher process requirements during the manufacturing process. For example, in the exposure and development stages, black solder mask may require more precise parameter control due to its strong light shielding, otherwise it is easy to have quality problems, such as short circuit hazards or appearance defects.
Color also has an impact on the product assembly and maintenance stage. For assembly workers, the high contrast between green PCB and white silk-screen text makes it easier for them to identify component locations and view line directions, which helps improve assembly efficiency and reduce the probability of errors. Black PCBs have disadvantages in this regard. Its lines are not easy to see clearly, which is more troublesome during debugging and maintenance.
From the perspective of product performance, color may have a certain impact on heat dissipation and electromagnetic compatibility (EMC). In theory, black PCBs may have better performance in thermal radiation due to their darker color, which can help some high-power devices dissipate heat better.
In terms of electromagnetic shielding, if special additives are used to change the color of PCBs of different colors, these materials may affect the electromagnetic shielding performance. However, this situation is more complicated and related to the specific material formula.
In terms of product appearance design, color is very important. For consumer electronic products, such as mobile phones and computers, the color of the PCB can match the overall style and brand image of the product. For example, some high-end electronic products use black PCBs to create a cool and professional feeling, while some products with a fresh style may use white or light blue PCBs.
Are black PCBs more expensive?
Usually, black PCBs are more expensive for the following reasons:
- Material cost: Black solder mask materials may require more expensive pigments or additives, and character inks may also be more expensive due to color and quality factors.
- Production process: Black pigments absorb light strongly. In the exposure and development processes, it is easy to have process problems such as unclear circuit graphics due to insufficient light and reduced alignment accuracy between the solder mask and the circuit, which increases the scrap rate and leads to an increase in overall costs.
- Market demand and supply: Black PCB is generally used in high-end electronic products, and the market demand is relatively small. Suppliers cannot form economies of scale during production, which leads to an increase in unit price.
Why is green PCB cheaper?
Green PCB is cheaper for the following reasons:
1. Low material cost:
- Cheap raw materials: The raw materials of green solder mask ink are in sufficient supply in the market and are relatively cheap. For example, compared with the expensive pigments or additives used in some special color inks, the cost of green ink ingredients is lower.
- Adequate stock: Due to the widespread use of green PCBs, ink suppliers usually reserve a large amount of green ink, which further reduces procurement costs and reduces the risk of price fluctuations caused by shortages.
2. Mature production technology:
- Easy to process: The processing and printing of green solder mask ink is relatively easy, and no complex color adjustment and special treatment are required during the production process, which can improve production efficiency and reduce labor and time costs.
- Low scrap rate: The process of producing green PCB is very mature. In the exposure, development and other processes, the probability of quality problems of green PCB is low, and the scrap rate is low, which reduces the overall production cost.
3. Favorable market supply and demand relationship:
- Massive production: Green is the most common color of PCB, and the market demand is large, so manufacturers can carry out large-scale production. Through large-scale production, enterprises can make full use of production equipment and reduce the production cost of unit products.
- Strong versatility: Most electronic products have no special requirements for PCB color. Green PCB can meet the needs of most application scenarios. There is no need to adjust the production line or increase additional costs to meet the special color requirements of individual customers.
What color is FR4?
FR4 is a substrate material for PCB. It does not have a fixed color. Its main components are glass fiber cloth and epoxy resin. Its color is usually determined by the solder mask on the surface.
The most common color of FR4 circuit boards is green, because green solder mask is widely used in PCB manufacturing. But in fact, FR4 substrate can present a variety of colors after different surface treatments, such as black, blue, red, white, etc.
How to choose the color of PCB?
There are several main factors to consider when choosing the color of PCB:
1. Functional requirements:
- Green PCB: Green PCB is widely used because of its high clarity and low glare characteristics. The green solder mask contrasts sharply with the white text, improving readability while reducing glare and protecting the eyes.
- Black PCB: Black PCB provides high light shielding and aesthetics, and looks high-end and atmospheric, but it absorbs more heat and may increase the risk of overheating of sensitive components.
- Blue PCB: Blue PCB has good screen printing contrast and is suitable for applications that require high contrast, such as LCD installation.
- Red PCB: Red PCB is eye-catching and has high visibility, suitable for high-end electronic devices and occasions that require high-precision circuit boards.
- White PCB: White PCB appears clean and tidy in various environments, has high reflectivity, and is suitable for low-light environments or applications that require high contrast.
2. Application scenarios and environmental factors:
- Consumer electronics: Green PCB is widely used in consumer electronics due to its low cost and high contrast.
- High-end electronic equipment: Red and blue PCB are often used in high-end communication equipment, military electronic products and optical equipment due to their high visibility and contrast.
- Lighting industry: White PCB is often used in the lighting industry due to its high reflectivity.
3. Production process and cost-effectiveness:
- Production process: PCBs of different colors have different requirements for production process.
- Cost-effectiveness: Green PCB is the most widely used, and factories usually reserve a large amount of green paint, which is relatively low in cost. In addition, green is more friendly to the eyes and reduces fatigue caused by long-term work.
In short, the selection of PCB color should be considered comprehensively. If you pursue cost-effectiveness and mass production, choose green, which has low cost and mature technology; if you want to highlight the quality of high-end products, you can choose black, which has high cost but good appearance and texture; blue, red, etc. are determined according to specific scenarios, such as red for high visibility and blue for novel appearance. Comprehensive consideration can be made to choose the right one.