PCB resin chemistry and film

1, ABS resin

It is a ternary mixture of Acrylonitrile-Butadine-Styrane (Acrylonitrile-Butadine-Styrane), in which the rubber part of the butadiene can be corroded by chromic acid to form holes, and can be used as a landing point for chemical copper or nickel for further plating. Many parts on the circuit board are assembled by ABS plating.

2, a-stage A

Varnish refers to the glass fiber cloth or cotton paper that is used to reinforce the Prepreg during its manufacturing process. The Varnish (also translates as Varnish water) of the resin is still in its monomer and diluted by the solvent, known as the A-stage. When glass fiber cloth or cotton paper suction glue, and after hot air and infrared drying, the molecular weight of the tree finger will increase to the complex or Oligomer, and then attached to the reinforcing material to form the film. The resin state is called b-stage. When it is further softened by heat and further polymerized into the final polymer resin, it is called C-stage.

3. Bonding Sheet(layer) Bonding Sheet, then layer

Point to rigid multilayer board in order to laminate union “film”, or soft board “table protect layer” the next layer between its board face

B) Stage B) Stage

It refers to the semi-polymerization and semi-hardening state of thermosetting resin, such as the resin attached to the film glass fiber cloth after the a-stage immersion project of epoxy resin, which can be softened by further heating.

5, Copolymer

It is a copper layer pressed on the surface of CCL copper foil substrate. The copper foil required by the PCB industry can be obtained by electroplating or rolling, the former for general rigid circuit boards, or the latter for flexible boards.

6, Coupling Agent

Circuit board industry refers to the surface of the glass fiber cloth coated by a layer of “silane compound class”, make between epoxy resin and glass fiber combination, more a “bypass hooked” layer of chemical bonds between them have more powerful telescopic elastic and combined with the robustness, once the plate caused by strong heat and the expansion of the difference is very big, coupling agent will be able to avoid the separation of the two.

Linking, Crosslinking, linking, linking

ThermosetTIng Polymer is formed by the bonding of many monomers through their molecular bonds. The bonding process is called “crosslinking”.

8, The C Stage

In general substrate board, the resin can be divided into A,B,C and other three hardening (also known as polymerization or curing) stage. Take the most used epoxy resin as an example. Its Varnish is called a-stage; its Prepreq is called B-stage; Several semi-cured films and copper sheets were laminated and pressed again at high temperature to form the substrate. This irreversible fully hardened resin state is called C-stage.

9, D-glass D glass

It refers to the substrate made of glass fiber with very high boron content, so that its medium constant can be controlled lower.

10. Dicyandiamide(Dicy)

Is a kind of epoxy resin polymerization hardening required bridging agent, because of its molecular formula with primary amine (-NH2), secondary amine (= NH), and tertiary amine (≡NH) three strong active reaction base, is a rare excellent hardener, also known as Cyano-guanidine cyanide Guanidine. But because of the strong water absorption of the material, there is trouble in the plate to gather “recrystallization”, so it must be ground very fine to be mixed in the resin containing immersion.

11, DifferenTIal Scanning Calorimetry(DSC) micro Scanning thermal card analysis

Simply put, when a substance is heated, the rate of “heat” flowing into the substance (MCAL/SEC) varies at different temperatures. DSC is to measure this “heat flow rate” (or the rate of change in heat) at different temperatures. For example when a commercial epoxy resin is heated, its the heat flow rate at different temperatures and different, but is about to reach “the glass transition temperature, the rate of heat flow between each ℃ can appear very big change, the curve of turning point corresponding to the temperature of the transverse slope intersection, namely Tg for the resin, so the Tg DSC to determine available. DSC approach is to sample (S) and reference (R) at the same time heating, because of the two “heat capacity” is different, so the temperature is different, but the gap between the △T can be maintained unchanged. However, when it is near Tg, △T between them will change greatly, and DSC can measure the change of temperature difference. It is a modified “thermal differential analysis” (DTA). In addition to the DETERMINATION of polymer Tg, DSC can also be used to measure the specific heat of plastics, crystallinity, hardening crosslinking, and purity, is an important “thermal analysis” instrument.

12. Dip CoaTIng

It is a simple and inexpensive way to coat (the thickness of leather film is related to the viscosity and speed of coat). Prepreg (printed circuit board material) is always used in this way. It can be coated on the outside, and also seeps into the space of glass fiber cloth (hence it is also known as soaked material).

E-glass electronic grade glass

E-glass was originally owned by OWens-Corning Fiberglass Co. As a result of the circuit board industry has been used for a long time, it has become an academic noun. In addition to basic silicon and calcium, it contains very little potassium and sodium, but a lot of boron and aluminum. Its insulation and processability are good, has been widely used in circuit board substrate reinforcement purposes. Its composition is as follows: Boron oxide B2O3 5~10% Sodium oxide/potassium Na2O/K2O 0~2% Calcium oxide CaO 16~25% Titanium dioxide TiO2 0~0.8% Aluminum oxide A12O3 12~16% Iron oxide Fe2O3 0.05~0.4% silica SiO2 52~56% fluorin F2 0~1.0%

14. Epoxy Resin

It is an extremely versatile Thermosetting polymer, which can be used for molding, packaging, coating, adhesion and other purposes. In the circuit board industry, is the largest consumption of insulation and bonding resin, and glass fiber cloth, glass fiber mat, and white kraft paper composite board, and can accommodate all kinds of additives, in order to achieve the purpose of non-combustible and high function, as the base material of all levels of circuit board.

15. Exotherm (curve)

During the polymerization and hardening of various resins, the term refers to the curve of heat release over time. The time when the most heat is released is the highest point of the temperature curve. And Exothermic Reaction- it’s an Exothermic chemical Reaction.

16. Filament

It refers to the most basic unit of various fabrics, usually consisting of a single Yarn that is twisted into a single Strand or a multi-strand Yarn, and then woven into the required cloth by “warp” and “weft”. Filament refers to a continuous Filament or Staple.

17. Fill in weft direction

Fiberglass or printing mesh, in which the weft direction is usually less than the number of weft per unit length, so the strength is less. This word has a synonym Weft.

18, Flame Resistant

Refers to the circuit board in the insulation plate resin, in order to achieve a certain level of flame resistance (in the UL94 HB, VO, V1 and V2 level 4), adding some chemicals must be deliberate in resin formula, such as bromine, silica, alumina, such as FR – 4 in which more than 20% of the bromide), make the plank of performance can achieve certain flame resistance. Generally fire-resistant FR-4 will be marked with the manufacturer’s UL “red mark” watermark on the Warp of its substrate (double panel) surface to indicate that it is fire-resistant. The G-10 without flame retardant can only be printed with “green” watermarking in warp direction. There is a synonym for Flame Retardent, but the correct term for a circuit board is Fire Resist, which is irresponsible and should not be misrepresented by laymen.

19, Gel Time

It refers to the tree finger in b-stage. After receiving external heat, the tree finger changes from solid to fluid, and then slowly polymerizes and becomes solid again. During the process, the total “number of seconds” experienced by the softening “to appear colloidality” is called “colloidization time”. That is, in the process of multi-layer plate pressing, the flow glue can drive away the air and fill the ups and downs of the inner line. The number of seconds that can be used is the practical significance of glue time. This is an important feature of semi-cured film Prepreg.

20, Gelation Particle

The presence of transparent, pre-polymerized wax particles in the tree finger of b-stage film.