PCB News - Considerations for PCB design from the perspective of manufacturing process

Detailed explanation of related design parameters:

one. (It is commonly known as the conductive hole)
1.Minimum: 0.3mm (12l)

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

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

4. The distance between the pad and the outline line is 0.508mm (20mil

two. line
1. Minimum: 6mil (0.153mm). The minimum line distance is line-to-line, and the distance from line to pad is not less than 6mil. From the production point of view, the larger the better, the general rule is 10mil. Of course, if the design is conditional, the larger the better. This is very important. Design Must consider

2. 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 inner layer of the multilayer board is 8MIL) If the design conditions permit, the larger the design, the better, the line width rises, the better our factory produces, the better the yield It is very important that the general design convention is about 10mil, and the design must be considered

3. The distance between the line and the outline line is 0.508mm (20mil)

three. PAD pad (commonly known as plug-in hole (PTH))
1, Plug-in hole (PTH) The outer ring of the pad should not be less than 0.2mm (8mil) on one side. Of course, the larger the better. This is very important, and the design must be considered

2, Plug-in hole (PTH) hole-to-hole spacing (hole edge to hole edge) should not be less than: 0.3mm, of course, the larger the better, this point is very important, and the design must be considered

3. The size of the plug-in hole depends on you, but it must be larger than your component pin. It is recommended to be larger than at least 0.2mm or above, that is to say, the component pin of 0.6. You must design at least 0.8 to prevent processing tolerances. Make it difficult to insert

4. The distance between the pad and the outline line is 0.508mm (20mil)

Four. Solder mask
1. The plug-in hole opens the window, and the single side of the SMD window cannot be less than 0.1mm (4mil)

five. Characters (the design of the characters directly affects the production, the clarity of the characters is very relevant to the character design)
1. The character width should not be less than 0.153mm (6mil), the character height should not be less than 0.811mm (32mil), and the ratio of width to height should be 5, that is, the character width is 0.2mm and the character height is 1mm. kind

Six: Non-metalized slot holes The minimum spacing of the slot holes is not less than 1.6mm, otherwise it will greatly increase the difficulty of milling

Seven: Imposition
1. There are no gaps and gaps in the imposition. The gap of the gaps should not be less than 1.6 (board thickness 1.6) mm, otherwise it will greatly increase the difficulty of milling. The size of the imposition work board will vary depending on the equipment. The gap of the no-gap imposition is about 0.5mm and the process edge cannot be less than 5mm

Related considerations
1. The original document about the design
1. In the double-panel file pads, you must select the through hole attribute (Through) instead of the blind buried hole attribute (Paral), and the drilling file cannot be generated, which will result in missing holes.

2. When designing slots in PADS, please do not add them together with components, because GERBER cannot be generated normally. To avoid leaks, please add slots in DrillDrawing.

3. PADS is paved with copper, and the manufacturer is paved with Hatch. After the customer's original file is moved, it must be re-paved and saved (copper is paved with Flood) to avoid short circuits.

2. Documents about PROL99se and DXP design
1. The manufacturer's solder mask is based on the Solder mask layer. If the solder paste layer (Paste layer) is required, and the multi-layer (M ullayer) solder mask cannot generate GERBER, please move to the solder mask layer.

2. Do not set the contour line in protel99SE, it will not generate GERBER normally.

3. Please do not select the KEEPOUT option in the DXP file. The outline and other components will be screened and GERBER cannot be generated.

4. Please pay attention to the front and back design of these two kinds of files. In principle, the top layer should be the positive character, and the bottom layer should be the reverse character. The manufacturer superimposes the board from the top layer to the bottom layer. Pay special attention to single-chip boards, and don't mirror them at will! Maybe it's the opposite of doing it.

three. Other matters needing attention
1. The shape (such as board frame, slot, V-CUT) must be placed on the KEEPOUT layer or layer, and cannot be placed on other layers, such as silk screen layer and circuit layer. All slots or holes that need to be mechanically formed should be placed on one layer as much as possible to avoid leaks or holes.

2. If the shape of the mechanical layer and the KEEPOUT layer are inconsistent, please make special instructions. In addition, the shape should be given an effective shape. If there is an inner groove, the line segment of the outer shape of the board at the intersection with the inner groove needs to be deleted to avoid leakage inside the gong. Slots, slots and holes designed in the mechanical layer and the KEEPOUT layer are generally made without copper holes (copper is required when making film). If you need to process them into metal holes, please make special notes.

3. With three software designs, please pay special attention to whether the buttons need to be exposed to copper.

4. If you want to make metallized slots, the safest way is to put together multiple pads. This method will definitely not go wrong.

5. To place an order on the gold finger board, please make a special note about whether beveling is required.

6. For the GERBER file, please check whether the file has a few layers. Generally, the manufacturer will directly make it according to the GERBER file.

7. Under normal circumstances, gerber uses the following naming methods:

Component surface circuit: gtl Component surface solder mask: gts
Component surface character: gto surface line: gbl
Welding surface solder mask: gbs Welding surface character: gbo
Shape: gko Split hole diagram: gdd
Drilling: drll

The above is about the introduction of the precautions for PCB design from the manufacturing process. Ipcb also provides PCB manufacturers and PCB manufacturing technology.