International Classification of Basic Materials
Basic materials are the basis of any printed circuit board. They, namely their technological features, affect the total cost and future nuances of the operation of the dielectric.
International standards
IPC documentation
- IPC-TM-650 is a detailed, widely used reference guide of testing methods of foil-printed PCB.
- IPC-4101 - the document contains a list of technological requirements for basic PCB materials of commercial/military use.
- IPC-4103 - the documentation contains requirements for basic materials based on teflon (polytetrafluoroethylene) and other microwave PCB.
- IPC-4104 - the document contains data on the specification of HDI board materials.
ASTM
American standards for methods of testing and classification of PCB materials.
NEMA
European standards for classification, verification and production technology, most often considered in the production of single- and multi-layer PCB.
IEC
List of methods for testing product quality, as well as raw materials.
Types of basic materials
The fitting substrate with foil copper (subtractive technologies) are used as composites or polymers - laminated plastic which has passed the preliminary pressing, reinforced by:
- woven/non-woven fabric;
- organic or glass fiber;
- polytetrafluoroethylene threads- PTFE;
- various resins (phenolic, polyester, epoxy, polymeric, etc.) and their mixtures - multifunctional, mixed, etc .;
- hardeners - dicyandiamide, phenol-formaldehyde resin, isocyanurate and cresol novolac, p-aminophenol, etc .;
- powdered organic/ceramic fillers.
The basic materials can be both flexible and rigid. There are also liquid (pasty) bases of printed circuit boards. Let us consider types of dielectric bases according to the NEMA classification more detailed:
|
Brand of material |
Reinforcement |
Resin |
Description |
|
XXXPC |
Paper |
Phenolic |
Laminated pressed electrical insulating paper impregnated with a binding agent based on phenolic compounds - getinax. Flammability class: UL94-HB. The material is cheap and suitable for single-sided printed circuit boards. Colour: light brown. Feature: there is no possibility of metallization of via holes and finishing coat HASL. |
|
FR-2 и FR-1 |
Made in the form of getinax. Feature: fireproof properties. The main difference between FR-1 and FR-2 is the temperature regime of vitrification: for the first one - 130˚, for the second one - 105˚. Flammability class of materials: UL94-V0. |
||
|
FR-3 |
Epoxy |
Getinax impregnated with an epoxy binding agent. It is fireproof, it has high insulation resistance. |
|
|
CEM-1 |
Paper + glass |
The material is based on epoxy paper with the addition of glass fiber (FR-4) as one surface layer. Fireproof. It is widespread in the production of single-layer printed circuit boards, as a low-cost alternative to FR-4. Colour: milky white. Feature: there is no possibility of metallization of via holes. Flammability class: UL94-V0. |
|
|
CEM-2 |
The material is similar to CEM-1 by its nature, but it is not fireproof. |
||
|
CEM-3 |
Glass combined filling |
The basis is non-woven glass fiber with epoxy resin, the surface layer is smooth woven glass fiber. According to its technological characteristics it is similar to FR-4, it is used for the production of two- and multi-layer PCB. The material is fireproof. Colour: milky white. It can be easily processed (stamped and drilled). |
|
|
CEM-4 |
The material is similar to CEM-3, but it is not fireproof. |
||
|
FR-6 |
Non-woven fabric: |
Polyester |
Fireproof non-woven glass fabric with the addition of polyester binders. |
|
G-10 |
Fiberglass fabric |
Epoxy |
Fiberglass cloth with the addition of epoxy substances. Flammability class: UL94-HB. The ease of stamping makes optimal conditions for the production of PCB for wristwatches. |
|
FR-4 |
The most widespread fireproof epoxy fiberglass cloth. Thickness: 1.6 mm (8 layers). Maximum operating temperature: 130˚. |
||
|
G-11 |
Fiberglass with the addition of heat-resistant epoxy compounds. |
||
|
FR-5 |
Fireproof fiberglass with the addition of heat-resistant epoxy compounds. It is similar to FR-4, but the operating temperature is 140˚-180˚. |
Copyright: Sai Fon LLC
