Application of a whole phase microscope in the production of printed circuit boards
Role in incoming raw material inspection As a copper-clad laminate required for the production of multilayer PCB boards, its quality will have a direct impact on the production of multilayer PCB boards. Through the metallurgical microscope, the following important information can be obtained from the slices taken.
1.1 Thickness of copper foil, to check whether the thickness of copper foil meets the production requirements of multilayer printed circuit boards.
1.2 The thickness of the dielectric layer and the arrangement of the semi-cured sheet.
1.3 The arrangement of glass fibres in the insulation medium in the warp and weft directions and the resin content.
1.4 Metallographic microscopy laminate defects information Laminate defects are mainly of the following kinds.
(1) pinhole refers to a small hole that completely penetrates a layer of metal. For the production of higher wiring density of multilayer printed boards, is often not allowed to appear this defect.
(2) pitting and pits pitting refers to small holes that do not fully penetrate the metal foil: pits refers to the pressing process, may be used to grind the steel plate local point-like protrusions, resulting in pressure after the surface of the copper foil appeared after a gentle sagging phenomenon. Can be measured by metallographic section of the size of the hole and the depth of subsidence, to determine whether the existence of the defect is permissible.
(3) Scratch marks are shallow grooves made by sharp objects on the surface of copper foil. The width and depth of the scratch are measured by metallographic microscope section to determine whether the presence of the defect is permissible or not.
(4) Folds Folds are creases or wrinkles in the copper foil on the surface of the platen. The existence of this defect can be seen by metallographic section is not allowed.
(5) laminated hollow, white spots and blistering laminated hollow refers to the laminate should have resin and adhesive, but filling is incomplete and there is a lack of area; white spots occur inside the substrate, in the textile fabrics at the separation of glass fibers and resin phenomenon, manifested in the substrate under the surface of the dispersed white spots or "cross-hatched"; blistering Refers to the substrate between the layers or substrate and conductive copper foil, resulting in local expansion caused by local separation of the phenomenon. The existence of such defects, depending on the specific circumstances to determine whether to allow.
