According to the different equipment status, this article only applies to some PCB manufacturers.
One. Overlapped pads
The overlap of the pad (except for the surface mount) is the overlap of the holes. When drilling, the drill bit and conductor will be damaged due to multiple drilling holes.
Two. The abuse of the graphic layer
1., violation of conventional design, such as component surface design at BOTTOM level, welding surface design at TOP, resulting in file editing Shi Zheng reverse error, resulting in product scrapping.
2., if there is milling grooves in the PCB, it is to be drawn with KEEPOUT LAYER or BOARD LAYER layer. No other layers or pads are applied to avoid mismilling or milling.
3. double sided boards, if there is no need for metallized holes, should be further explained.
Three. Heterotypic hole
If there are irregular holes in the panel, draw a filling area just like the hole size with KEEPOUT layer. The length / width ratio of the special-shaped holes should be more than 2:3:1, and the width should be >1mm. Otherwise, the drilling machine will easily break the cutter when machining the irregular holes, which will cause difficulties in processing.
Four. The placement of characters
The 1. character is to cover the pad SMD solder, which will cause inconvenience to the PCB's on-off test and component welding.
2. character design is too small, resulting in screen printing difficulties, so that the characters are not clear enough. The character height is larger than 30mil, the width is more than 6mil.
Five. Setting of aperture of single side pad
1., the single side pad usually does not drill. If the hole needs to be marked, its aperture should be designed to be zero. If we design the numerical value, when drilling data, it will drill holes, and it will affect the appearance of the board and the discard of the boards.
2., if you want to drill holes, you need to make special marking.
Six. Draw a weld plate with a filled block
The padding plate can be checked by DRC on the design line, but it is not good for processing. Therefore, the welding disk can not produce the welding data directly. When the solder is resisted, the filler area will be covered by the resistance welding agent, which leads to the difficulty of the device welding.
Seven, there are too many padding blocks in the design, or fill blocks are filled with very thin lines.
1., the phenomenon of missing data is generated, and the data is incomplete and the shape is distorted.
2., because the fill block is painted on line by one line in the process of data processing, the amount of data drawn by light is quite large, which increases the difficulty of data processing.
Eight. Surface mounting device is too short
For the off test, the spacing between the two feet is very small for the too dense surface mounting device, and the weld plate is very thin. The installation test must go up and down (right and right), for example, the design of the plate is too short, although it does not affect the mounting of the device, it will make the test needle wrong.
Nine. The space between large area grids is too small
The large area grid line is too small (less than 0.30mm) between the same lines, which will cause short circuit in the printing process.
Ten. The distance from the large area of copper foil to the outer frame is too close
The large area of copper foil should be at least 0.20mm above the distance, because in milling shape, such as milling to copper foil may cause copper foil to warp and cause the flux loss caused by it.
Eleven. The design of the outline of the border is not clear
Some customers have designed contour lines in KEEP LAYER, BOARD LAYER, TOP OVER LAYER and so on. It is difficult to determine which one is the outer line when forming.
Twelve. Line placement
Two joints between the wire, do not break intermittent painting, if you want to add rough lines do not use lines to repeat, directly change the line WIDTH, so the words in the modification of the line is easy to modify.
Thirteen make-up.
The track system of automatic welding equipment has a size range of gripping PCB board, and the clamping range of general production line is 50mm*50mm-460mm*460mm. PCB in small 50mm*50mm need to be designed into the form of imposition.
A.PCB must have its own reference point (Mark), which is conducive to automatic location of welding equipment.
B. if the V cutting processing the imposition spacing should be maintained at 0.3mm, the technology for single 5mm.
C. for complex PCB, the PCB rules should be ensured as far as possible, so as to track clamping.
D. the same PCB can be put together, and different PCB can also be put together.
E. panel can be used flat row, row of Yuanyang, in the form of.
