High-precision multilayer circuit board,plating hard gold or immersion gold

High-precision multi-layer circuit board manufacturers in the circuit board, if there is signal transmission, it is hoped that the power supply will start to transmit to the receiving end with minimal energy loss, and the receiving end will completely absorb it. Do not make any reflections. To achieve this type of transmission, the impedance in the line must be equal to the internal impedance of the output, which is called "impedance matching." Impedance matching is one of the design elements when designing high speed PCB circuits. The impedance value has an absolute relationship with the routing method. For example, whether the distance between the surface layer (Microstrip) or the inner layer (Stripline/Double Stripline), the reference power layer or the ground layer, the trace width, and the PCB material affect the characteristic impedance of the trace. That is to say, the impedance value can be determined after wiring, and the characteristic impedance produced by different PCB manufacturers is also slightly different. General simulation software can not consider some discontinuous wiring conditions due to the limitation of the line model or the mathematical algorithm used. At this time, only some terminators (Temninators), such as series resistors, can be reserved on the schematic. Moderate the effect of discontinuity in the trace impedance. The only way to solve the problem is to pay attention to avoiding impedance discontinuities

For the technological innovation of printed circuits, people have been pursuing semi-additive and additive techniques, that is, depositing copper layers on insulating substrates to form circuit patterns. This is an improvement on the traditional subtraction method. Energy consumption and high cost. The new road to innovation is Printed Electronic Circuits (PEC), which revolutionizes PCB products and manufacturing processes. Printed electronic circuit technology uses pure printing method to realize electronic circuit graphics, that is, screen printing or offset printing or inkjet printing process, printing functional inks (conductive ink, semiconductor ink, insulating ink, etc.) on insulating substrate On, get the required electronic circuit. This technology simplifies production processes, saves raw materials, and reduces pollutants

High-frequency circuits tend to have high integration and high wiring density. The use of multi-layer boards is both necessary for wiring and an effective means to reduce interference. Protel for Windows V1.5 can provide 16 copper layers and 4 power layers. Reasonable selection of layers can greatly reduce the size of the board, make full use of the middle layer to set the shield, and better achieve near grounding. Ground reduction of parasitic inductance, can effectively shorten the transmission length of the signal, can greatly reduce the cross interference between signals, etc.

All of these are beneficial for the reliable operation of high-frequency circuits. When the data shows the same material, the four-layer board is 20dB lower than the noise of the double-layer board, but the higher the number of layers, the more complicated the manufacturing process and the higher the cost. Multi-layer circuit board manufacturers

The less the lead bend between the pins of the high-speed circuit device, the better. The lead wire of the high-frequency circuit wiring is preferably a full line, and the turn can be turned by a 45-degree fold line or a circular arc. This requirement is only used to improve the fixing strength of the steel foil in the low frequency circuit, and meeting this requirement in the high frequency circuit can reduce the external emission and mutual coupling of the high frequency signal. When wiring with Protel, you can pre-set it in two places: one is to reserve 45/90 Line or 90 ArcLine in the Track Mode submenu of the Options menu; the second is the RoutingPasses dialog opened in the Setup Autorouter item of the Auto menu. Select Add Arcs in the middle, so that the corners are rounded at the end of the automatic routing

Why use a gold plate? Multi-layer circuit board In order to solve the above problems of gold-plated plates, the PCBs using the immersion gold plate mainly have the following characteristics: 1. Because the crystal structure formed by Shenjin and gold plating is different, Shenjin will be golden yellow and more yellow than gold plating, and customers are more satisfied. 2. Because the crystal structure formed by immersion gold and gold plating is different, immersion gold is easier to weld than gold plating, which will not cause poor welding and cause customer complaints. 3. Because the gold plate has only nickel gold on the pad, the signal transmission in the skin effect is not affected by the signal in the copper layer. 4. Because of the gold plating, the crystal structure is denser and it is not easy to produce oxidation. 5, because the gold plate only has nickel gold on the pad, so it will not produce gold wire and cause it to be short. 6. Because the gold plate has only nickel gold on the pad, the solder joint on the line is more firmly bonded to the copper layer. 7. The project will not affect the spacing when making compensation. 8. Because the crystal structure formed by immersion gold and gold plating is different, the stress of the immersion gold plate is easier to control, and it is more conducive to the processing of bonding for the products with bonding. At the same time, because Shenjin is softer than gold plating, the gold plate is not wearable. 9. The flatness and standby life of the Shenjin plate are as good as the gold plate.