PCB circuit board production process requirements are extremely strict,
which requires familiarity with the PCB board manufacturing process, and the
production equipment and testing equipment are accurate to produce a good PCB
board. Many PCB board manufacturers are not very long. If you are, you may
encounter some common mistakes, take a look at what is there, and how to avoid
One. The pads overlap.
1. Causes heavy holes, which cause breakage and hole damage during drilling
due to multiple holes in one place.
2. In the multi-layer board, there are both lands and spacers in the same
position, and the board is made to be isolated and connected incorrectly.
Second, the graphics layer is not standardized
1. Violation of conventional design, such as the design of the component
surface in the Bottom layer, the welding surface design on the TOP layer,
2. There are a lot of design garbage on each layer, such as broken lines,
useless borders, labels, etc.
Third, the characters are unreasonable
1. Characters cover the SMD soldering piece, which brings inconvenience to
PCB continuity detection and component soldering.
2. Characters are too small, making screen printing difficult, too large
will make characters overlap each other, difficult to distinguish, the font is
generally > 40mil.
Fourth, single-sided pad setting aperture
1. Single-sided pad is generally not drilled, and its aperture should be
designed to be zero. Otherwise, when drilling data is generated, the coordinates
of the hole appear at this position. For example, the hole should be specially
2. If the single-sided pad is to be drilled, but the aperture is not
designed, the software will treat the pad as an SMT pad when outputting the
ground and ground data, and the inner layer will drop the isolation disk.
Fifth, draw pads with padding
Although this can be checked by DRC, the solder resist data cannot be
directly generated during processing, and the pad is covered with the solder
resist and cannot be soldered.
Sixth, the electric ground layer design both the heat sink and the signal
line, and the positive image and the negative image are designed together and
there is an error.
7. The spacing of large-area grids is too small. The spacing of grid lines
is <0.3mm. During the PCB manufacturing process, the pattern transfer process
produces broken film after development to cause wire breakage.
8. The pattern should be at least 0.2mm or more from the outer frame (V-cut
is 0.35mm or more), otherwise the copper foil will be lifted and the solder
resist will fall off during the external processing. The appearance quality will
be affected (including the multilayer board). Layer copper).
Nine, the shape of the frame design is not clear Many layers have been
designed with a frame, and do not coincide, making it difficult for PCB
manufacturers to determine which line to form, the standard frame should be
designed in the mechanical layer or BOARD layer, the internal hollowing out to
10. When the graphic design is uneven, the current distribution is uneven
when the pattern is electroplated, which affects the uniformity of the plating
layer and even causes warpage.
XI, shaped hole is short
The length/width of the shaped hole should be >2:1 and the width should
be >1.0mm, otherwise the CNC drilling machine cannot be processed.
Twelve, undesigned milling shape positioning hole
If possible, design at least 2 positioning holes with a diameter of
>1.5mm in the PCB.
Thirteen, the aperture is unclear
1. The aperture mark should be marked as metric as much as possible, and in
increments of 0.05
2. Combine the apertures that are likely to be merged into one library area
as much as possible.
3. Whether the tolerances of metallized holes and special holes (such as
crimping holes) are clearly marked.
Fourteen, the inner layer of the multi-layer board is unreasonable
1. The heat sink pad is placed on the isolation tape, and it is easy to be
connected after drilling.
2. The isolation belt is designed with a gap and is easy to
3. The isolation strap design is too narrow to accurately determine the
Fifteen, buried blind hole plate design problem
The significance of designing buried blind plates:
1. Increase the density of multi-layer boards by more than 30%, reduce the
number of layers and reduce the size of multi-layer boards.
2. Improve PCB performance, especially control of characteristic impedance
(wire shortening, aperture reduction)
3. Improve PCB design freedom d. Reduce raw materials and costs, which is
conducive to environmental protection.
PCB board production, no matter what company, will encounter some big and
small problems, but the way to deal with the problem and the ability to prevent
it is very important. If a problem occurs repeatedly but has not been resolved,
then the PCB manufacturer should review it. Of course, when choosing a PCB
manufacturer, try to choose the strength + technology precipitation time is
long, after all, experience is still very important.
This issue: What are the common mistakes in the PCB manufacturing process? How to avoid it? If you have any other things you don't understand, please call
us or consult our customer service staff online!