Some basic points to note when designing PCB board:

I. Detailed explanation of related PCB design parameters

1. The line

(1) 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. If the design conditions permit, the larger the design, the better the line width, the better the factory production, the higher the yield. The general design convention is around 10mil, this point is very important, must be considered in the design.

(2) Minimum line spacing: 6mil(0.153mm). Minimum line distance, that is, line to line, line to pad distance is not less than 6mil from the production point of view, the larger the better, the general general in 10mil, of course, the design conditions, the larger the better this point is very important, must be considered in the design.

(3) Distance from line to contour line 0.508mm(20mil)

2. Via hole (commonly known as conductive hole)

(1) Minimum aperture :0.3mm(12mil)

(2) The minimum through hole (VIA) aperture should not be less than 0.3mm(12mil), pad unilateral should not be less than 6mil(0.153mm), preferably greater than 8mil(0.2mm) is not limited (see Figure 3) this point is very important, must be considered in the design

(3) through hole (VIA) hole to hole spacing (hole side to hole side) should not be less than :6mil better than 8mil this point is very important, must be considered in the design

(4) Distance between pad and contour line 0.508mm(20mil)

(5) a. Hole to line spacing:

NPTH(without welding ring) : hole compensation 0.15mm back distance line more than 0.2mm

PTH(with welding ring) : hole compensation 0.15mm and above the distance line 0.3mm

B. Hole-to-hole spacing:

PTH(with welded ring) : 0.15mm after hole compensation to 0.45mm or more

NPTH hole: 0.15mm to 0.2mm after hole compensation

VIA: The spacing can be slightly smaller

3. PAD PAD (commonly known as plug hole (PTH))

(1) The size of the plug hole depends on your component, but it must be larger than your component pin. It is recommended that the plug pin be larger than at least 0.2mm, that is to say, 0.6 of the component pin, you should design it as 0.8 at least, in order to prevent the machining tolerance caused by difficult insertion.

(2) Plug hole (PTH) outer ring unilateral side should not be less than 0.2mm(8mil), of course, the larger the better (as shown in Figure 2) this point is very important, design must be considered

(3) Plug hole (PTH) hole to hole spacing (hole edge to hole edge) should not be less than: 0.3mm of course, the larger the better (as marked in FIG.3) This point is very important, must be considered in the design

(4) Distance between pad and contour line 0.508mm(20mil)

4. The welding

(1) Plug-in hole window opening, SMD window opening side should not be less than 0.1mm(4mil)

5. Characters (the design of characters directly affects production, and the clarity of characters is very related to the design of characters)

(1) the character word width can not be less than 0.153mm(6mil), the word height can not be less than 0.811mm(32mil), the width ratio to height ratio of the best relationship is 5 that is to say, word width 0.2mm word height is 1mm, in order to push the class

6. The minimum spacing of non-metallic grooves should not be less than 1.6mm, otherwise it will greatly increase the difficulty of edge milling (Figure 4)

7. Puzzle

(1) collage with or without gap collage, and with gap collage, the collage gap with gap should not be less than 1.6 mm (thickness of 1.6)mm, otherwise it will greatly increase the difficulty of milling edge collage work plate size is not the same depending on different equipment, the gap of no gap collage about 0.5mm process edge can not be less than 5mm

Ii. Relevant matters needing attention

1. Original document on PADS design.

(1)PADS are laid in copper mode, and our company lays copper in Hatch mode. After the original files of the customer are moved, they should be re-laid with copper for preservation (Flood laying copper) to avoid short circuit.

(2) Face properties in dual-panel PADS should be set to Through, not ParTIal. Drilling files cannot be generated, resulting in drilling leakage.

(3) Do not add the designed grooves in PADS together with the components, because GERBER cannot be normally generated. In order to avoid slot leakage, please add grooves in DrillDrawing.

2. Documents about PROTEL99SE and DXP design

(1) Our company’s Solder mask layer is subject to Solder mask layer. If the Paste layer needs to be made, and the Solder window with multiple layers cannot generate GERBER, please move to the Solder layer.

(2) Do not lock the contour line in Protel99SE. GERBER cannot be generated normally.

(3) In the DXP file, do not choose KEEPOUT option, it will screen the contour line and other components, unable to generate GERBER.

(4) Please pay attention to the positive and negative design of these two kinds of documents. In principle, the top layer is positive, and the bottom layer should be designed as reverse. Our company makes plates by stacking from top to bottom. Single plate special attention, do not mirror at will! Maybe it’s the other way around

3. Other precautions.

(1) Shape (such as plate frame, slot, V-cut) must be placed in KEEPOUT layer or mechanical layer, can not be placed in other layers, such as screen printing layer, line layer. All slots or holes that need mechanical molding should be placed in one layer as far as possible to avoid leakage.

(2) if the mechanical layer and KEEPOUT layer two layers of appearance is inconsistent, please make special instructions, in addition to the shape to effective shape, such as there is an inner groove, and the inner groove intersection plate outer shape of the line segment need to be deleted, leak-free gong inner groove, design in the mechanical layer and KEEPOUT layer groove and hole is generally made by copper hole (do film to dig copper), If it needs to be processed into metal holes, please make special remarks.

(3) If you want to do the metalized slot the most safe way is to put together a plurality of pad, this approach must not go wrong

(4) Please make a special note on whether it is necessary to do the bevel processing when placing the order of gold finger plate.

(5) Please check whether there are fewer layers in the GERBER file. Generally, our company will directly produce according to the GERBER file.

(6) Use three kinds of software design, please pay special attention to whether the key position needs to expose copper.