SMT equipments with fully automatic, high precision, high speed, high efficiency and so on, PCB design must meet the requirements of the SMT equipments.
SMT equipments on the design requirements include: PCB shape, size, positioning holes and clamping edges, datum mark (Mark), board assembling, selection of components packaging and packaging forms, PCB design output files, etc. When PCB design, first consider the PCB shape.
PCB design, the first thing to consider the shape of the PCB. PCB form factor is too large, printed lines long, impedance increases, anti-noise capability decreases, the cost also increases. Too small, the heat dissipation is not good, and the neighboring lines are susceptible to interference. At the same time, the accuracy of the PCB form factor and specifications directly affect the manufacturability and economy of production and processing. the main elements of the PCB form design are as follows.
1. Aspect ratio design
The shape of the PCB should be as simple as possible, generally rectangular, aspect ratio of 3:2 or 4:3, its size should be as close as possible to the standard series of dimensions, in order to reduce processing, reduce processing costs. Board surface should not be designed too large, so as not to cause deformation after SMT reflow oven. Board size and board thickness to match the size of the thin PCB, the board size can not be too large.
2. PCB shape
PCB shape and size is determined by the mounter machine PCB transfer mode, mounting range.
① When the PCB is positioned on the mounting table, the PCB is transmitted through the table, there is no special requirement for the shape of the PCB.
② When the guide rail is directly used to transfer the PCB, the PCB shape must be straight. If it is a shaped PCB, must be designed so that the process edge of the PCB outside the formation of a straight line.
③ In the PCB shape design, it is best to process the PCB into rounded corners or 45 ° chamfer to prevent damage to the PCB conveyor belt (fiber belt) on the board when the sharp corners.
3. PCB size design
PCB size is determined by the mounting range. In the design of PCB, be sure to consider the maximum and minimum mounting size of the mounter machine. PCB maximum size = maximum mounting size of the placement machine, PCB minimum size = minimum mounting size of the placement machine. Different models of placement machine placement range is different. When the PCB size is smaller than the minimum mounting size must be used when the collocation method.
4. PCB thickness design
General mounter machine allows the board thickness of 0.5 ~ Smm. PCB thickness is generally within the range of 0.5-2mm.
① Only assembly of integrated circuits, low-power transistors, resistors, capacitors and other low-power components, in the absence of strong load vibration conditions, the size of 500mm x 500mm PCB, the use of thickness of 1.6mm.
② Load vibration conditions, can be taken to reduce the size of the board or reinforcement and increase the support point, you can still use 1.6mm thickness.
③ When the board surface is large or cannot be supported, 2 -3mm thick board should be selected.
Features of NeoDen N10P mounter machine
1. Support PCB within size (L)1500mm*(W)450mm.
2. Automatic nozzle change function has been added to the system. 39 nozzle positions increase the speed and flexibility of integrated placement.
3. IC camera improves the size of IC photos and realizes automatic calibration with automatic nozzle change.
4. Automatic calibration of nozzle height.
5. Increase the convenience of recycling material by adding a throw box.
6. 80 tape feeders to increase the number of simultaneous feeding capacity.
7. Measuring of nozzle air pressure to improve work stability and eliminate obstacles.
8. Optimized software design to improve ease of use and stability.
Post time: Nov-14-2024