PCB Technical - Red, black, green... the color of the PCB board is exquisite

Get a PCB board, the most intuitively displayed before our eyes is its color. Common PCB board colors are green, black, blue, red, yellow, etc. What are the special features of PCB boards of different colors?

Green PCB

Green PCB is currently the most common and cheapest on the market. why? The main reasons are as follows:

1.Green is less irritating to the eyes.Since childhood, the teacher told us that green is good for the eyes, protects the eyes, and resists fatigue. The production and maintenance personnel are not prone to eye fatigue when staring at the PCB board for a long time, and it is less harmful to the eyes.

2.Lower cost. Since green is the mainstream in the production process, the purchase of natural green paint will be larger, and the purchase cost of green paint will be lower than other colors. At the same time, using the same pcb board color paint in mass production can also reduce the replacement cost.

3.When the board is soldered in SMT, it needs to go through tinning, post filming and final AOI verification. These processes all need to be optically positioned and calibrated. The green background color is better for the recognition of the instrument.

Black PCB

Some people think that black PCB boards represent high-end, but in fact this perception is incorrect. The reason why "color represents high-end or low-end" is because manufacturers like to use black PCBs to make high-end products, and red, blue, green, and yellow to make low-end products.

In addition, the black PCB, because its surface traces are almost completely covered, cause great difficulty in later repairs, so it is a color that is not convenient to manufacture and use, and the black PCB is the most difficult for holes, so it is a good product The rate is relatively lower than that of other color PCB boards, so the price of black is relatively more expensive.

Blue PCB

The difference between PCBs of different colors is the color of the solder mask that is applied at the end. If the PCB design and manufacturing process are exactly the same, the color will not have any effect on performance, nor will it have any effect on heat dissipation.

The pcb board coloris not only a matter of appearance, but its choice can have a direct impact on the performance of the product, including:

Maintainability: Board colours vary significantly in terms of visibility and maintainability.For example,black and dark coloured boards are not easy to identify in low-light environments, making them more difficult to repair.

Thermal performance: Certain board colours can affect thermal performance to some extent.For example,black boards absorb heat better than other colours and are suitable for high temperature applications.

Production Costs: Green boards are often more economical to produce than other colours because green paint can be purchased in larger quantities and the production process is relatively simple. This makes green boards the default choice for many manufacturers.

PCB board solder mask

Printed circuit board usually consists of pads, vias,solder mask,silk screen,copper wires,various components and other parts.Among them, the solder mask (solder mask) refers to the part of the printed circuit board to be painted with green oil.Through the previous introduction,we already know that solder mask ink is not only green,but also red,yellow,blue,purple,black, etc., but green is the most common.

The role of solder mask:

(1) Prevent physical disconnection of conductor circuits;

(2) In the welding process, prevent short circuit caused by bridging;

(3) Only solder the parts that must be soldered to avoid waste of solder;

(4) Reduce copper pollution to the soldering trough;

(5) Prevent insulation deterioration and corrosion caused by external environmental factors such as dust and moisture;

(6) With high insulation,it is possible to increase the density of the circuit.

Different colors of soldermask inks can have a variety of potential cost implications in circuit board manufacturing:

Soldermask Purchasing Costs

Low procurement cost of green inks:Green soldermask is the most widely used ink on the market and manufacturing companies tend to produce this ink in large quantities, so the procurement cost of green inks is lower compared to other colours.In addition,green inks are in relatively good supply, and almost all manufacturers will have them in stock.

Relatively higher costs for other colors:For other colors such as blue, black, red, etc., soldermask inks are usually more expensive to purchase as the demand is low and the production process can be relatively complex.

The impact of the manufacturing process on cost

Process adaptability:Although the colour of soldermask has no direct impact on the performance of the finished product,different colours of soldermask may require different process parameters and quality control measures during the production process. This means that manufacturers may need to adjust their production equipment and processes when switching between different ink colours, thus increasing costs.

Equipment Maintenance and Cleaning:Inks of different colours may have different compositions and properties, and the volatiles released may also vary. This may result in more frequent cleaning and maintenance of equipment when using different inks, increasing operating costs.

Cost impact of finished product quality

Economics and Market Positioning:Different coloured soldermasks not only have a visual impact,but can also affect the competitiveness of a product in the marketplace. For example, black or red circuit boards are often seen as high-end products for which consumers may be willing to pay a higher price.As a result,these colours may be more economically viable in certain markets, despite their higher cost.

Compliance Requirements and Inspections: Certain colours of soldermask may affect the efficiency of quality testing and compliance inspections.This can have a negative impact on the total cost of ownership if manufacturers need to invest in additional human resources for inspection,or if the color results in higher rework rates.

The choice of pcb board color is not only a simple aesthetic requirement,it is closely linked to a number of aspects such as market positioning,product functionality and maintenance. In the product design process,these factors should be considered comprehensively,so as to select the most appropriate circuit board colour to meet the dual needs of functionality and aesthetics.