Preparation method of stepped semi-copper hole PCB

Abstract

The invention relates to a preparation method of a stepped semi-copper hole PCB, which adopts a separate plating and separate drilling method to prepare a stepped semi-copper hole, and comprises the following steps: S1, carrying out electroless plating copper plate electroless plating and inner layer pattern electroless plating, carrying out outer layer hole sealing pattern after electroless plating copper plate electroless plating and before inner layer pattern electroless plating, and exposing a hole needing copper plating while sealing the outer layer, then, pattern hole plating is carried out on the exposed hole, hole copper is thickened, and high-temperature glue does not need to be pasted behind an inner layer pattern; s2, making inner layer patterns on the L5-L6 layers respectively; and S3, laminating L1-L4 laminated semi-finished products prepared in the steps S1 and S2 and L5 and L6 layers with inner-layer patterns together, and respectively performing first drilling and second drilling before and after the electrodeposition of the copper plate, so that high-temperature glue pasting before the electrodeposition of the copper plate and forming groove milling, laser drilling and outer-layer circuit pattern forming are not required to be performed in sequence after the second drilling, and the stepped semi-copper hole PCB is prepared. The preparation method of the stepped semi-copper hole PCB has the advantages of being good in product quality, high in yield, high in production efficiency and the like.

Description

technical field [0001] The invention relates to the technical field of PCB preparation, in particular to a method for preparing a PCB with stepped half-copper holes. Background technique [0002] With the development of 5G products, the design requirements for PCB signals are getting higher and higher. For the conduction and model requirements of products, methods such as back drilling are often required to meet product requirements, and back drilling has Stub piles. Existing Drilling stub capacity is 5-8mil. When the interlayer thickness of the customer is less than 5mil, or the stub requirement is 0mil, and the existing back-drilling method cannot meet the demand, other production methods are required to meet this requirement. [0003] At present, for the production of stepped hole PCB, taking a 6-layer board as an example, the L1-L4 layer holes require copper plating, and the L4 layer step groove position, the L4 layer needs to retain the PAD, and the L4-L6 layer position...

AI Technical Summary

Problems solved by technology

[0002] With the development of 5G products, the design requirements for PCB signals are getting higher and higher. For the conduction and model requirements of products, methods such as back drilling are often required to meet product requirements, and back drilling has Stub piles. Existing Drilling stub capacity is 5-8mil. When the interlayer thickness of the customer is less than 5mil, or the stub requirement is 0mil, and the existing back-drilling method cannot meet the demand, other production methods are required to meet this requirement

[0003] At present, for the production of stepped hole PCB, taking a 6-layer board as an example, the L1-L4 layer holes require copper plating, and the L4 layer step groove position, the L4 layer needs to retain the PAD, and the L4-L6 layer position is copper-free design. Due to the large aspect ratio of the L1-L4 layer in the plated hole method, the electroplating cannot meet the demand, and there are stub residues in the back drilling method

The existing method adopts back drilling or separate plating, the production process is complex and the yield rate is low, and when the L1-L4 layer is produced, it is necessary to paste high-temperature glue on the L1-L4 layer before lamination, and the L1-L6 When making layers, after drilling, it is necessary to paste high-temperature glue on the back-drilled holes of the L1-L4 layer. Since the high-temperature glue cannot be machine-operated, manual glue application will result in low operating efficiency and problems such as sticking crooked and resulting in scrapping. Glue removal is corrosive to the colloid, which can easily lead to deep penetration of the potion, resulting in residues, which in turn affects product quality and leads to problems such as low yield