Many friends have asked me about the technology related to PCB multilayer board manufacturing. Here, I will elaborate on this topic in great detail. The manufacturing process encompasses various techniques such as high-density interconnection (HDI) printed boards using the build-up method, the semi-additive method for achieving precision fine lines (with a line width and spacing as small as 0.08mm), thermosetting Ink Layering Method (TCD), plating and filling blind hole technology (Via Filling), as well as high-end special material printed board manufacturing technology.
1. High-Density Inner Layer Connection (HDI) PCB Circuit Board Technology Using the Build-Up Method:
The build-up method, in conjunction with manufacturing blind holes, is a novel technique. This method involves initially processing the inner layer following the conventional multi-layer board processing method, then stacking layers one atop the other—two or more layers—which we term as build-up layers or SBU layers. Micro-vias (blind holes) connect the SBU layer to its adjacent layers. Proficiency in this technology requires mastery of the following:
A. Laser Drilling Technology:
Although a laser drilling machine can drill holes ranging from 2mil to 8mil in diameter, laser drilling technology is significantly more intricate than ordinary mechanical drilling. Factors such as differing anti-material, plate thickness, and hole diameter necessitate varying laser energy levels. Hence, systematic experimentation and testing are imperative to determine drilling parameters suitable for different boards, ensuring drilling quality.
B. Micro-via Plating Technology:
HDI boards typically feature buried and blind holes, with buried hole diameters around 0.3mm and blind hole diameters ranging from 0.1mm to 0.15mm. Unlike conventional PCBs, which lack blind holes and have a minimum through-hole diameter of 0.5mm, HDI board production requires addressing blind hole plating challenges. Employing positive and negative pulse electroplating power supplies, coupled with enhanced electroplating line designs, ensures the thickness ratio of the plating layer in blind holes to surface plating layers approximates or exceeds 1:1, thereby guaranteeing the HDI board’s reliability.
C. Fine Line Production Technology:
High-density circuit boards are characterized by extremely narrow line widths and spacings. Traditional methods struggle to achieve lines below 4 mils. Advanced DES (developing, etching, stripping) lines, along with suitable dry film and exposure technology, enable the realization of lines as small as 3mil/3mil in width and spacing, with ongoing research focusing on achieving 2mil/3mil and 2mil/2mil configurations.
1. High-Density Inner Layer Connection (HDI) PCB Circuit Board Technology Using the Build-Up Method:
The build-up method, in conjunction with manufacturing blind holes, is a novel technique. This method involves initially processing the inner layer following the conventional multi-layer board processing method, then stacking layers one atop the other—two or more layers—which we term as build-up layers or SBU layers. Micro-vias (blind holes) connect the SBU layer to its adjacent layers. Proficiency in this technology requires mastery of the following:
A. Laser Drilling Technology:
Although a laser drilling machine can drill holes ranging from 2mil to 8mil in diameter, laser drilling technology is significantly more intricate than ordinary mechanical drilling. Factors such as differing anti-material, plate thickness, and hole diameter necessitate varying laser energy levels. Hence, systematic experimentation and testing are imperative to determine drilling parameters suitable for different boards, ensuring drilling quality.
B. Micro-via Plating Technology:
HDI boards typically feature buried and blind holes, with buried hole diameters around 0.3mm and blind hole diameters ranging from 0.1mm to 0.15mm. Unlike conventional PCBs, which lack blind holes and have a minimum through-hole diameter of 0.5mm, HDI board production requires addressing blind hole plating challenges. Employing positive and negative pulse electroplating power supplies, coupled with enhanced electroplating line designs, ensures the thickness ratio of the plating layer in blind holes to surface plating layers approximates or exceeds 1:1, thereby guaranteeing the HDI board’s reliability.
C. Fine Line Production Technology:
High-density circuit boards are characterized by extremely narrow line widths and spacings. Traditional methods struggle to achieve lines below 4 mils. Advanced DES (developing, etching, stripping) lines, along with suitable dry film and exposure technology, enable the realization of lines as small as 3mil/3mil in width and spacing, with ongoing research focusing on achieving 2mil/3mil and 2mil/2mil configurations.
