The most common are double sided printed circuit boards, they contain two dielectric layers connected by a two-sided topology. The conductors between the layers are combined into a single structure with the help of through transitional/assembly metallized holes.

— Industrial home appliances
— IPower supplies
— ISecurity fire alarm systems
— IMeasuring equipment and control systems
— IMilitary electronics and telecommunication

Among the main dielectric materials of double-layer circuits are:
— composite based on fiberglass - FR-4;
— phenolic composition FR-2;
— CEM-1 - cellulose base with a layer of fiberglass.
— CEM-3 - epoxy based composite.

The combined positive method is the most frequently used method of producing a topology on double-layer printed circuit boards. When producing simple boards, the technological parameters of which satisfy the standard ones, one more combined manufacturing method is used - the tenting method.

Manufacturing processes

Due to the optimization of technological operations, in comparison with the production of MPCB, two-layer printed circuit boards have a low cost and short production time.

Thickness, mm

0,5−2,2

0,3−4

Maximum standard size, mm

200×200

500×800

Tolerances:

— thickness, %

±10

— plate size, mm

± 0,127

± 0,1

— hole diameter (metallized), mm

± 0,1

± 0,076

— hole diameter (not metallized), mm

± 0,1

± 0,058

— width of conductors, %

± 30

± 25

Ratio of the board thickness to the metallized hole diameter

8:1

10:1

Minimum values:

— gap/conductors width, mm

0,2

0,125

— hole copper rim, mm

0,15

0,125

— through hole diameter, mm

0,4

0,125

— "conductors — opening masks" distance, mm

0,1

0,075

— "mask — platform" openings, mm

0,1

0,075

— silkscreen text height, mm

1,5

1,25

Width of silkscreen lines, mm

0,2

0,15

Liquid solder mask color

Green, red, blue, yellow, super white, white and black

Marking paint color

Green, black, white