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Juding circuit technology high-precision impedance PCB circuit board mass production

2019-09-24 23:37:02 462

    High-precision impedance PCB circuit board mass production and manufacturing of high-frequency electronic equipment is a development trend, especially in the development of wireless networks and satellite communications, information products are moving toward high-speed and high-frequency, and communication products are moving toward large-capacity wireless transmission. Standardization of voice, video, and data. Therefore, the development of a new generation of products requires high-frequency substrates, satellite systems, mobile phone receiving base stations and other communication products must use high-frequency circuit boards, and will inevitably develop rapidly in the next few years, high-frequency substrates will be in large demand.


Multi-layer PCB: In the more messy application requirements, the circuit can be settled into multiple layers of planning and pressed together, and through-hole circuits are connected between the layers to connect the various layers of circuits. The inner layer copper foil substrate is first cut into specifications suitable for production and production.


Before the substrate is pressed, the copper foil on the copper surface is usually properly roughened by brushing and micro-etching, and then the dry film photoresist is closely attached to it at an appropriate temperature and pressure. The substrate with the dry film photoresist is sent to the ultraviolet exposure machine for exposure, and the photoresist will be polymerized after being irradiated by the ultraviolet rays in the transparent region of the film (the dry film in the region will be in the process of later development and copper etching). It is saved as an etch resist), and the line image on the film is transferred to the dry film photoresist of the board. After tearing off the maintenance film on the film surface, the unexposed area on the film surface is developed and removed with an aqueous solution of sodium carbonate, and the exposed copper foil is etched away with a mixture of yansuan and hydrogen peroxide to form a line. At the end, the dry film photoresist which is repelled by the aqueous solution is washed away with an aqueous solution. The impedance circuit board is mass-produced.


Multilayer multi-layer board process and technology:


Core board production---lamination RCC---laser drilling---porous plating---graphic transfer---etching and stripping---lamination RCC---repeating the integrated printing forming anb structure Circuit board (HDI/BUM board).


(Note 1): The core board here refers to various boards such as a conventional double-sided, multi-layer board, a buried/blind-hole multilayer board, and the like. However, these core plates must be subjected to plugging and surface smoothing before they can be laminated.


(Note 2): The multilayer (HDI/BUM) multilayer board structure can be expressed by the following formula. Anba- is the number of layers stacked on one side, n- is the core board, and b- is the number of layers laminated on the other side.

Drilling and sinking copper


Purpose: Metallize the through holes:


1 The substrate of the circuit board is composed of copper foil, glass fiber and epoxy resin. After the substrate is drilled, the cross-section of the hole wall is composed of the above three parts.


2-hole metallization is to solve the problem of covering a uniform layer of heat-resistant metal copper. Hole metallization is to solve the problem of covering a uniform layer of heat-resistant metal copper.


3 The process is divided into three parts: one to the drilling process, the second chemical copper process, and the three thick copper process (full plate copper plating).


[Welding-proof ink Text printing] The earlier green lacquer was produced by direct thermal drying (or UV irradiation) to cure the paint film after screen printing. However, due to the fact that during the printing and hardening process, the green paint penetrates the copper surface of the terminal of the line to cause the welding and use of the parts. Now, in addition to the simple and rough circuit board, the photosensitive green paint is used instead. in production.


The text, trademark or part number required by the customer is printed on the board by screen printing, and then the text paint is hardened by hot baking (or ultraviolet irradiation).


Pad processing manufacturing:


The solder mask green paint covers most of the copper surface of the circuit and only exposes the terminal contacts for soldering, electrical testing and board insertion. This endpoint requires an additional protective layer to avoid oxides at the terminals of the anode (+) that are connected during long-term use, affecting circuit stability and creating safety concerns.


Shenzhen Juding Circuit Technology Co., Ltd. is a professional PCB circuit board manufacturer, providing you with: PCB prototype, batch processing board, 1-34 layer PCB board, TG board, HDI board, Rogers board, microwave board, RF board, Radar board, thick copper foil board, etc. Various process and material PCB boards for the manufacture and production of PCB boards