Ensure that the printed circuit board net list is consistent with the net list described in the schematic diagram in the early stage of the 1..

The 2. PCB layout needs to be checked after it is roughly completed.

Overall dimension

Confirm that the outline drawing is up-to-date

Confirm that the outline drawing has taken into account the wiring prohibition area, transmission edge, barrier edge, splicing, etc.

Confirm that the PCB template is up to date

Compare the outline drawings to confirm that the dimensions and tolerances marked on the PCB are correct, and the metallized holes and non-metallized holes are accurately defined.

Confirm that the layout of the no wiring area on the outline drawing is reflected on the PCB.

Whether the digital circuit and the analog circuit have been separated, whether the signal flow is reasonable

Whether the layout of the clock device is reasonable

Whether the layout of high-speed signal devices is reasonable

Whether the termination device has been properly placed (series resistance should be placed at the driving end of the signal, and other termination methods should be placed at the receiving end of the signal)

Whether the number and location of decoupling capacitors in IC devices are reasonable

Whether the layout and relative position of protection devices (such as TVS and PTC) are reasonable

Whether devices that may affect EMC testing are placed in accordance with design guidelines or reference to success. For example, the reset circuit of the panel should be slightly close to the reset button.

Heavier components should be placed close to the PCB support point or support edge to reduce PCB warpage.

Heat-sensitive components (including liquid medium capacitors, crystal oscillator) as far as possible away from high-power components, radiators and other heat sources

Whether the height of the device meets the requirements of the outline drawing for the height of the device

Within the range of 5mm around the crimping socket, the front side is not allowed to have components whose height exceeds the height of the crimping socket, and the back side is not allowed to have components or solder joints.

In the PCB axial plug-in higher components, should consider horizontal installation. Leave room for sleeping. And consider the fixing method, such as the fixed pad of the crystal oscillator.

Metal shell components, pay special attention not to other components or printed wire collision, to leave enough space position

Motherboard and daughter board, single board and backplane, confirm that the signal and position are corresponding, and the connector direction and silk screen mark are correct.

Open the place-bound of TOP and BOTTOM layers to see if DRC caused by overlap allows wave soldering surface. The types of SMD allowed to be laid are: patches R, C, SOT and SOP above 0603 (including 0603) (pin center distance ≥ 1mm)

Wave soldering surface, SMD placement direction should be perpendicular to the PCB transfer direction during wave soldering

The wave soldering surface, the shadow effect area is 0.8mm (perpendicular to the PCB transmission direction) and 1.2mm (parallel to the PCB transmission direction), and the tantalum capacitor is 2.5mm in the front. Distinguish by pad spacing

Whether components are placed by 100%

Whether the package library has been updated (check the running result with viewlog)

Device Packaging

Print 1:1 layout, check layout and packaging, hardware designer to confirm

Pin sequence of device, pin 1 mark, polarity mark of device, direction mark of connector

Whether the screen printing size of the device package is appropriate, and whether the text symbols of the device meet the requirements of the standard.

Whether the hole diameter of the through hole pad of the plug-in device is appropriate and whether the metallization definition of the mounting hole is accurate.

Whether the width and length of the pad of the surface mount device are appropriate (the margin of the outer end of the pad is about 0.4mm, the margin of the inner end is about 0.4mm, and the width should not be less than the maximum width of the pin)

Whether the package of resistance and capacitance of reflow soldering surface and wave soldering surface is distinguished