Why are most printed circuit boards green while Apple is black?

Apple products not only make an impression by external appearance but also interior. The skilled engineers who dissected the interior of every Apple MacBook are impressed with the clean black circuit board with components neatly arranged inside.

Unlike Apple, the majority of other electronics firms often choose green for their circuit boards . For many people, this green looks boring but why is it still used in most electronic devices so far?

Picture 1 of Why are most printed circuit boards green while Apple is black?
The vast majority of other electronics companies often choose green for their circuit boards.

In fact, that green is not the circuit board itself, but the plastic layer that covers the circuit board. The purpose of this plastic layer is to protect copper conductors on the circuit board surface from oxidation, as well as prevent the formation of electrical bridges between welds with surrounding electrical paths. And in the early days of wave soldering, it helped prevent solder from accidentally spilling into the circuit board during welding.

This shows that the role of the plastic coating around the board is not related to its color, why are most printed circuit boards green?

In fact, colors covering these printed circuit boards come in many different colors, such as green, red, yellow, blue and black.

But many years ago, when manufacturing printed circuit boards, companies used glass fiber epoxy resin, which is naturally green. So the original printed circuit boards are usually green. Gradually this green became the default element for circuit boards because of its effect in the inspection of welds.

Picture 2 of Why are most printed circuit boards green while Apple is black?
That green is not of the circuit board itself, but of the plastic layer that covers the circuit board.

Green is chosen to cover most printed circuit boards because it is the color that makes the eyes the least regulating when looking at. When the weld inspection is still done manually, this will be very helpful for circuit board testing. Currently, even if the inspection has been automated, it is still necessary to have several inspectors before completing. Therefore, green is still effective in increasing performance in the production process.

When green becomes the default choice for printed circuit board manufacturers, this kind of color becomes much easier to find and cheaper than most other colors. This further motivates manufacturers to continue to produce on green printed circuit boards, maintaining its dominance on circuit boards.

However, along with automation in circuit board testing process is getting more and more complete, the use of green on printed circuit boards becomes increasingly unnecessary.

At the same time, by the early 2000s, manufacturers began to pay more attention to the color of printed circuit board PCBs, partly because of the need to distinguish grades between their products. Therefore manufacturers often use two different colors to distinguish between high-end product lines and their lower-end product lines.

For example, Asus often uses yellow for its regular motherboards and black for higher-end motherboards. Many other board manufacturers also choose black to represent their higher-end product line.

Picture 3 of Why are most printed circuit boards green while Apple is black?
Apple TV circuit uses Apple A5 chip.

Not only because of the color, part of the reason that the black board is considered to be more advanced is that it is more difficult to punch on printed circuit boards, so they have lower productivity, as well as cost. finished higher than circuit boards with other colors.

However, the blackboard started to become a symbol of high-end products since they were used by Apple in circuit boards for MacBook computers and their other devices. Under the impact of Apple, black circuit boards are also increasingly being used by other manufacturers.