Some feasible processes on PCB production

- Dec 21, 2019-

Some feasible processes on PCB production

Summary of content: When receiving orders, processing engineering data and production processes, we often find that some customers' designs do not meet the feasibility requirements of the PCB production process. Of course, this is not to say that the level of designers is limited, but because most design engineers have not visited the PCB factory to understand how to produce a qualified PCB board, and they know too little about PCB production, which has led to the design. The main reason that there is no way to process and produce boards or problems in the production process, so I hope the following can help engineers engaged in PCB design.

Detailed design parameters:

First, the line

1. The minimum line width: 6mil (0.153mm). That is to say, if the line width is less than 6mil, it will not be able to produce (the minimum line width and line spacing of the multilayer board is 8MIL). If the design conditions permit, the larger the design, the better, the line width will increase, the better the factory production, the higher the yield The general design routine is around 10mil. This is very important and the design must be considered.

2. Minimum line spacing: 6mil (0.153mm). . The minimum line distance is the line-to-line, and the distance from the line to the pad is not less than 6mil. From the production point of view, the larger the better, generally 10mil. Of course, if the design is conditional, the bigger the better. This is very important. Design Be sure to consider.

3. 0.508mm (20mil) from line to outline line

 

Second, via vias (commonly known as conductive holes)

1. Minimum aperture: 0.3mm (12mil)

2. The minimum via hole (VIA) aperture is not less than 0.3mm (12mil), and the single side of the pad must not be less than 6mil (0.153mm), preferably greater than 8mil (0.2mm). It is not limited. This is very important, and the design must be consider.

3. Via (VIA) hole-to-hole distance (hole edge to hole edge) should not be less than 6mil, preferably more than 8mil. This is very important and the design must be considered.

4. 0.508mm (20mil) from pad to outline line

 

Third, PAD pads (commonly known as plug-in holes (PTH))

 

1. The size of the plug-in hole depends on your component, but it must be larger than your component pins. It is recommended to be greater than at least 0.2mm, that is, 0.6 component pins. You must design at least 0.8 to prevent processing. Tolerances make it difficult to insert.

2. Plug hole (PTH) The outer side of the pad must not be less than 0.2mm (8mil). Of course, the bigger the better, this point is very important, and the design must be considered.

3. Plug-in hole (PTH) The hole-to-hole distance (hole edge to hole edge) cannot be less than: 0.3mm, of course, the bigger the better, this point is very important, and the design must be considered

4. 0.508mm (20mil) from pad to outline line

Fourth, welding

Plug-in window opening, SMD window opening side cannot be less than 0.1mm (4mil)

 

Five, characters

The design of the characters directly affects the production. Whether the characters are clear or not depends on the design of the characters.

The width of characters should not be less than 0.153mm (6mil), and the height of characters should not be less than 0.811mm (32mil). The ratio of width to height is preferably 5. That is to say, the width of 0.2mm is 1mm, and so on.

 

Six: Non-metallized slot

The minimum distance between slots is not less than 1.6mm, otherwise it will greatly increase the difficulty of milling.

 

Seven: Imposition

     1. Imposition is divided into gapless imposition and gapped imposition. The imposition clearance with gap imposition should not be less than 1.6 (thickness of 1.6) mm, otherwise it will greatly increase the difficulty of milling. The size of the imposition work panel varies depending on the equipment. The gap of the gap imposition is about 0.5mm, and the craft side is generally 5mm.

  2. The size of the imposition V-cut must be greater than 8cm, because the V-cut will fall into the machine when the V-cut is less than 8cm, and the V-cut width must be less than 32cm. Production process limitations, not something we can't do

3. The V-cut can only go straight. Because of the shape of the board, it can't go straight. You can add space for stamp hole bridge connection and related precautions.

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