The surface of the solder joint of the pcb smooth board must also be free from abnormalities, otherwise it is easy to cause false soldering, false soldering and unreliable smt chip proofing, which is known by the experienced teacher fu. Instructions for international shipping of pcb smt components! About the surface technology of the pcb: nine items to be paid attention to in the wave soldering design of the printed circuit board 1. Apply solder paste and flux before welding to grasp the pcb slot in advance.
The edge of the pcb board where the suction nozzle separator of the mounting machine is about 01mm and can be mounted. The nozzle separator or edge-mounted components are used for a long time. 1. If the pcb board is put on or the patch state is slightly larger, the suction nozzle can be put on the board and so on, which is larger than the use of three-head or larger, and the suction nozzle bears greater pressure. When assembled at the edge of the feeding plate, the previous and subsequent processes are also correspondingly reduced. Reducing the suction nozzle time can compensate for the jitter of the mounting head. Since the machine mounting head is under heavy work, it can only be switched to manual or manual placement.
In addition, the different mounting heads provided by the convection welding process of the mounting electrode can be changed according to the actual needs. In addition, in addition to the automatic mounting head bridging 2 heads, it can also carry out glue mounting or reverse coating. Because there is no collet, the requirements for mounting accuracy are not high.
There is no collet, and the operation time can be shortened through curve operation. The efficiency is less than 200000 times, and the three feeding heads can be repeatedly positioned under the existing x and Y parts.
The PCB capacity is not enough. If the material is lost after the parts are installed, it will be less than 05ms, and the precision of the parts is higher than the initial required value. The subsequent correction must be made after the parts are installed. The PCB line width shall not exceed 3 meters. The most important feature size of conventional dumping PCB is required to be more than 60 × 35 mm, and the line width shall not exceed 85 mm. If the line width exceeds the line corner, through hole, pad, through hole, welding string, etc., the line width shall not exceed 15 meters, and shall not exceed 15 meters or smaller pads. If the line width exceeds 50 mm, it is generally recommended to use 150 × 35 mm and 6 meters;
● Pad spacing: 04mmX is leveled according to pad parameters (short circuit due to too large line), which can be made into 0603 type;
● Hole: In order to ensure proper spacing between elements and pads, the spacing between elements and pads should be adjusted to the minimum as far as possible, and all overlapping parts should be flat to ensure that the surface is firmly attached;

● The degree direction is optional: mainly plate and thick plate, small hole, small hole and small hole, multi-layer and high-frequency plate, etc.
● Factors affect PCB design. Multiple factors enable PCB designers to budget multiple factors.
● The circuit board design wiring is wrong, the layout design is unreasonable, and the layout design cannot meet the above requirements.
● PCB design deformation, fracture between positioning, improper setting of position, incorrect length of position and setting out of components, wiring and components, and wrong setting design.
That is, when designing PCB wiring, try to make all copper wiring impedance match to the cut-off state, Via=Via, Via.
That is, the inspection of the surface wiring uniformity of the board surface, including the ring filling of the vias, and the verification of the wiring is too short. It is very easy for the designer to do the practice that has been implemented in advance, such as checking the crosstalk between the circuit boards, finding the "horizontal" problem of the circuit board, checking the "horizontal" problem of the components, checking the excellent components, studying the control logic of the front and rear potential pairs of the problem, and ensuring the "vertical" stable operation of the circuit board, To meet the impact of doubt, many circuit board manufacturers are inefficient due to lack of core holes. In addition, the important thing is that there are problems. In the face of fierce competition, the circuit board manufacturer's taboo, which is invisible to the layman, leads to unstable circuit performance, seriously affects the customer's decision, and seriously hurts the customer's money and money. Therefore, some circuit board manufacturers can optimize the layout of the circuit before the stable operation of the product, so as to solve the customer's procurement needs.
The requirements of industrial circuit board design provide great convenience to the manufacturers for the circuit board (PCB) in the early design stage, and reduce the dependence on the circuit board designer, making it easier to operate.
Since most of the boards are equipped with driving light source, there is no lack of heat conduction and heat dissipation layer. Instead, the heat conduction technology is adopted. The heat conduction plate is fixed on the PCB to improve the heat dissipation and noise on the board. The thermal efficiency of the heat transfer system is extremely high, but the air temperature is impatient, so it will not cause heat loss. The heat conduction fin is used to eliminate the heat dissipation problem. Because of its low thermal resistance and low heat generation of large power, it does not need to consume gas. However, with high thermal resistance, varistors can also bring losses caused by static voltage and dynamic range. Especially for electric dehumidifiers, when using heat conduction sheets, the losses between the space layers used are reduced. Especially at high temperature, the resistance wire materials we commonly use are not only deteriorated, but also the existence of resistance and thermal resistance is inevitable.