GB/T 39342-2020Aerospace electronic products—General specification for printed circuit board (English PDF)

4.1 Design

4.1.1

When designing a printed board, the important characteristics of the printed board related to reliability should be considered comprehensively, such as the structure of the printed board, the choice of substrate, and the layout of the printed board.

Bureau, wiring, printed wire width and wire spacing, via (via), land pattern design, dielectric layer thickness, copper foil thickness and printed board manufacturing

And installation process, etc., and should have an appropriate safety factor according to the importance of the printed board in the complete product.

4.1.2

The printed board design should meet the manufacturability requirements. Manufacturability includes the manufacturability of printed board manufacturing and electronic assembly

Performance requirements, while testing and maintainability should be considered. The manufacturing process of the printed board mainly considers the thickness, size, number of conductor layers, and wire precision of the board.

Factors such as the minimum width and spacing of wires, interconnection methods (through holes, buried holes and blind holes), minimum aperture, plate thickness and aperture ratio.

4.1.3

The material and structure of the printed board should be able to adapt to the use environment requirements of aerospace electronic and electrical products, and the maximum use of renewable, recyclable or environmentally friendly materials should be used.

4.2 Materials

4.2.1

Copper clad laminates generally use substrates with high thermal reliability and flame retardancy. When the electronic assembly uses a higher soldering temperature, the substrate glass

The glass transition temperature is generally not less than 170°C.

4.2.2

When selecting a substrate, other properties should be considered on the basis of meeting the key characteristics of the product, and a suitable substrate should be selected according to the following factors.

a) Type of printed board;

b) manufacturing process;

c) Working and storage environment;