The introduction of PCB material

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PCB is the core component of electronic devices. Insulation and durability are the basic requirements, and at the same time, it must be resistant to high temperatures. Therefore, when choosing PCB raw materials, we must consider these factors. Now let’s take a look at some issues with PCB materials. More information can be sent to us by email.

1. PCB material concept

The material is simple: what the object looks like. Material can be seen as a combination of materials and texture. PCB material refers to the materials used in the production line board, including substrates, substrate parameters, and process. It mainly refers to the quality of copper-covers (copper plates) composed of substrate, copper foil and adhesive.

2. PCB material composition

The main materials of the printed board (PCB) are copper coated plates (copper plates) composed of substrate, copper foil and adhesive. The substrate is an insulating layer composed of synthetic polymer resin and reinforced materials; pure copper foil with high conductivity and good welding on the surface of the substrate, which is commonly used 35-50 / mA; copper foil is covered on the substrate board. The copper covering plate on one side is called a single-sided copper covering plate. The copper covering plate covered with copper foil on both sides of the substrate is called a double-sided copper plate; whether the copper foil can be firmly covered on the substrate, it is completed by the adhesive. The thickness of copper coated plates is 1.0mm, 1.5mm, and 2.0mm.

There are also many types of copper-coated plates. It can be divided into paper substrates, glass cloth substrates and synthetic fiber plates according to different insulation materials; according to the different adhesive resin, it is divided into phenolic, epoxy, polytic and polytrafluoroethylene; Essence

3. Structures and characteristics of commonly used copper coated plates

Copy phenolic copper foil paper laminate

It is a suppression layer made of insulating immersion paper (TFZ 1:62(Cotton fiber dip paper (1TZ-1):63(1)) soaked by phenolic resin through heat pressure. Two surface adhesive sheets may be a single alkaline-free glass immersion cloth. It is applied with copper foil. It is mainly used as a printed circuit board in radio equipment.

Copper foil phenolic glass cloth laminated pressure plate

It is a laminate product made of epoxy phenolic resin by heat pressing epoxy phenol. It has the advantages of light, good electrical and mechanical properties, and convenient processing. Its plate surface is pale yellow. If triamine is used as a curing agent, the surface of the plate is pale green and has good transparency. It is mainly used as printed circuit boards on radio equipment with high operating temperature and frequency.

Copper foil polytetrafluoroethylene laminate

It is a copper plate made of polytetrafluoroethylene board, and the copper foil is pressed by heat. It is mainly used for printed boards in high-frequency and ultra-high-frequency lines.

Copper foil epoxy glass cloth laminated pressure plate

It is commonly used for hole metal-based printed boards.

Soft polyester copper film

It is a tapered material, which is mainly compressed with a polyester film and copper heat, and is rolled into a spiral shape inside the device in the application. In order to strengthen or moistureproof, it is often poured into a hole with epoxy resin. It is mainly used as a flexible printed circuit and a printed cable, which can be used as a transition line for plug-ins.

At present, the copper covering board supplied on the market can be divided into the following categories: paper base boards, glass fiber cloth plates, synthetic fiber cloth boards, non-woven layers, and composite substrates.

The following types are commonly used on copper-coated plates:

FR-1-phenolic cotton paper, this substrate is commonly referred to as electric wooden boards (higher economy than FR-2).
FR-2 ─ Phenolin cotton paper,
EN-3 -Cotton paper, epoxy resin
FR-4 ─ Woven Glass, epoxy resin
FR-5-glass cloth, epoxy resin
FR-6-f f f, polyester
G-10-glass cloth, epoxy resin
CEM-1-cotton paper, epoxy resin (flame retardant)
CEM-2-cotton paper, epoxy resin (non-flame retardant)
CEM-3-glass cloth, epoxy resin
CEM-4-glass cloth, epoxy resin
CEM-5-glass cloth, polyester
Ain – aluminum nitride
SIC-silicon carbide

What factors should be considered for PCB board selection?

PCB boards have very different scenes, products, performance, materials, area, etc., which leads to very many changes in the types of components used in different PCB boards, the thickness of the connection line, and the density of the wiring. Therefore, the choice of PCB board must be considered.

(1) For -like electronic products, the FR4 epoxy glass fiber substrate is used; for the use of high ambient temperature or deflection circuit board, polypelide glass fiber substrates are used; Fluorine glass fiber substrates; for electronic products with high heat dissipation requirements, metal substrates should be used.

(2) The glass transition temperature (TG) should be appropriately selected. The TG value should be higher than the operating temperature of the circuit.

(3) The heating coefficient (CTE) is required to be low.

(4) High heat resistance to the plate is required. Generally, PCB is required to have heat resistance of 250 ° C/50s.

(6) The flatness of the board is required.

(7) In terms of electrical performance, for high frequency circuit board materials, materials with high dielectric constants and small medium loss, including insulation resistance, voltage resistance strength, and anti-arc performance, must meet product requirements.

Summarize

Materials and craftsmanship determine PCB quality. Therefore, many customers often pay attention to PCB board materials and process requirements when customizing PCB boards. Leadsintec focuses on PCB manufacturing and processing. We provide services to global companies.