PCB News - The distinction and pros and cons of circuit board plates

The distinction and pros and cons of circuit board plates

1. Terminology: Military-grade A-grade sheet material: refers to the highest-grade sheet material of a sheet manufacturer, the insulation of the sheet, the uniformity of the sheet, the reliability of the copper skin and the base material of the sheet, and the impedance stability of the sheet, Far higher than the B-grade and C-grade materials in similar products, and can be used to produce military electronic products with absolutely demanding requirements!

Low-grade board grade B and C materials: board manufacturers, because of the low-cost needs of circuit board manufacturers, produce boards. This type of board, the board manufacturer, in the process of manufacturing, shoddy and cut corners ! In terms of performance stability, it is far inferior to military-grade A-grade materials, and the price is much lower than that of A-grade materials.

2. Board grade classification of general plate manufacturers:

Grade A: The best grade plate, meeting the requirements of military industry grade, industrial requirements, and quality assurance;

Grade B: Low-grade plates are used for low-grade civilian use without quality assurance;

Grade C: The lower grade is purely for cost, and there is no guarantee of quality.

3. FR-4 (PCB circuit board) composition

1. Fiberglass cloth;

2. Resin;

3. Copper foil.

Four. Comparison of materials used in different grades of plates and the hazards of low-grade plates:

Summary: Compared with the a-level materials, the b-level and c-level materials are cutting corners. The shoddy charge is good, and the glass fiber cloth is not good, which directly leads to the instability of the circuit board, which leads to the instability of the circuit board, which leads to the instability of your electronic products. Instability, seeing this also roughly understands why the copper foil is easy to fall off!

5. How to recognize that it is a grade A sheet material and ensure that your circuit manufacturer does not use low-grade sheet material

A grade material

Method 1: In addition to the mark, the contract should also indicate that it is a grade A material, otherwise all the responsibilities caused by the plate will be borne by the board factory;

Method 2: Generally, all the grade A materials of the board manufacturers will be marked, like the A grade in the Kingboard (kb) material, the word kb is in the board, if it is other grades like the B and c in the kb If the performance is poor, there is no mark, so the easiest way to distinguish is to see if there is a mark in the board (Note: The mark exists in the board, if there is copper on it, it will not be found. If there is no line, that is The etched area will be displayed),

VI. Uncover the unspoken rules of the industry

90% of the unspoken rules of circuit board factories in Shenzhen are to use materials B and C that have no performance guarantee. Except for some other factories, the performance requirements are stricter and use A grade materials! This is why foreign products, even those manufactured in China, have stable performance, while domestic products in China always have problems of one kind or another. The most fundamental reason is that the materials used are several grades. It is an unspoken rule of the industry. If you can deal with bad things, you don’t have to be good. What's more, for a non-professional you, sometimes you can’t tell the original. There are all kinds of sheets in the plate warehouse. Customers don’t ask for it. Knowing, and thus knowing the maximization of profit, the most direct result of this is that it damages the customer's right to know and harms the interests of customers. In fact, this is not conducive to the long-term development of the circuit board industry in the long run!

Seven, the harm of bad plates

Bad boards are entirely made up of cutting corners or shoddy materials. It is conceivable that the performance is not good, and the harm it can bring is of course. I also said that the most important part of electronic products is the circuit board. The quality of the circuit board depends largely on the circuit board. If the circuit board is not good, it will bring harm to your electronic board.

1. During soldering, the pad is very easy to fall off, which will lead to the destruction of the entire board;

2. The circuit board undergoes slight deformation after a period of operation, and the deformation and contraction of the circuit board result in unstable performance;

3. The change of the material of the board will cause a more serious problem, which will deform your circuit and make your circuit board in a completely unstable state;

4. For repaired, if the board fails, the pad will easily fall off, and the side will directly cause the repaired product to be destroyed, resulting in serious losses.