A manufacturing process of thick copper high aspect ratio small aperture motherboard

Abstract

The invention discloses a manufacturing process for a thick-copper high-aspect-ratio and small-pore-diameter main board. The manufacturing process is characterized by comprising the following steps of step 1, performing board cutting; step 2, drilling holes; step 3, performing an electroless thick-copper plating operation; step 4, performing full-board electroplating for the first time; step 5, performing full-board electroplating for the second time; step 6, pattern transferring; step 7, pattern electroplating; step 8, etching an outer layer; and step 9, inspecting the outer layer; the manufacturing process is characterized in that in the step 3, the circuit board after being drilled in the step 1 is subjected to high-voltage water-washing processing for two times to ensure that dust in the holes is fully cleaned and the holes are clean; the pore diameter after thick-copper plating is determined based on that the thickness of the thick-copper plated in the circuit board hole achieves 45-70[mu]m; the high-aspect-ratio board hole wall copper is thickened by the electroless thick-copper plating process to strength the conductive performance in the full-board electroplating; the thickness in the hole is consolidated again through the way of full-board electroplating for the first time; the full-board electroplating for the second time is adopted to assist the full-board electroplating uniformity, so that the whole PNL PCB copper thickness uniformity process ensures that each region can satisfy the various standards of industrial IPC.

Description

technical field [0001] The invention relates to the technical field of mainboard production, in particular to a production process for a thick copper high aspect ratio small aperture mainboard. Background technique [0002] The electroplating of the aspect ratio through hole is a key point in the multilayer PCB board manufacturing process. Since the ratio of the board thickness to the aperture is 10:1 higher (and higher requirements), the copper plating layer can be uniformly covered in the entire The difficulty in the hole wall is very great. Due to the small diameter and high depth of the through hole, it is difficult to meet the process requirements during the entire processing process. The process step that is most likely to cause quality problems is the removal of epoxy drilling smears, that is, etchback, which makes it difficult to control the depth of microetching of etchback, because it is difficult for the small and deep etchback liquid to pass through the entire h...

AI Technical Summary

Problems solved by technology

Holes are formed so that the subsequent sinking copper cannot cover all, and voids will appear

The second is that during the copper sinking process, the exchange of the solution is blocked, and it is very difficult to replace the fresh copper sinking solution, which greatly reduces the coverage of the sinking copper

The third is that the dispersion ability of electroplating cannot meet the process requirements, and it is easy to dissolve part of the copper sinking layer, forming voids or no copper plating layer, etc.