scope:

This specification covers the generic performance requirements for rigid, multilayered (three or more conductor layers) printed wiring boards (hereafter designated printed board) with plated holes, that will use soldering for component/part mounting (see 6.1.1).

Classification. Printed boards are of classified by 1.2.1 and 1.2.2, as specified (see 6.2).

Printed board type. Printed boards covered by this specification sheet are of the following types:

3 - Rigid multilayer board without blind or buried vias.

4 - Rigid multilayer board with blind and/or buried vias.

Composition. The composition designation is defined by the resin system of the dielectric base material (see 6.7) as follows:

M - Mixed based material printed boards. Printed boards of this composition contain layers of two or more different types of thermosetting resin base materials (see 6.7.2).

S - Homogenous thermosetting base material printed boards. Printed board of this composition contain only one type of thermosetting resin base materials (see 6.7.3).

Wrap copper plating grade. The wrap copper plating grade designation is defined by the amount of plated-through hole surface and knee continuous copper plating thickness remaining after surface processing. The grades are as follows:

A - Printed boards of this grade have 80 percent or more of the specified plated-through hole wrap copper plating thickness on the surface and knee after surface processing.

B - Printed boards of this grade have 50 percent or more of the specified plated-through hole wrap copper plating thickness on the surface and knee after surface processing.

C - Printed boards of this grade have 20 percent or more of the specified plated-through hole wrap copper plating thickness on the surface and knee after surface processing.

Unless otherwise specified, the default grade of wrap copper plating is grade A for printed board designs that will not undergo planarization and grade B for designs that require planarization.

intended Use: