PCB Technical - PCB anti-interference FPC and FPC imposition instructions

Improve the anti-interference performance of PCB sensitive equipment

Improving the anti-interference performance of PCB sensitive equipment refers to the consideration of minimizing the interference noise of sensitive equipment

And a way to recover from the abnormal state as soon as possible.

Common measures to improve the anti-interference performance of PCB sensitive equipment are as follows:

(1) Minimize the area of the annular ring during PCB wiring to reduce induced noise.

(2) When wiring, the power wire and ground wire should be as thick as possible. In addition to reducing the pressure drop, reducing the coupling is more important and the noise adds up.

(3) For single-chip idle I/O ports, please do not hover, ground or connect to power. Other idle ICS terminals are grounded or connected to power without changing the system logic.

(4) The use of single-chip power supply monitoring and watchdog circuits, such as IMP809, IMP706, IMP813, X25043, X25045, etc., can greatly improve the anti-interference performance of the entire circuit.

(5) In terms of speed, it can meet the requirements of the circuit under the premise of minimizing the single-chip crystal vibration and low-speed digital selection.

(6) IC devices are soldered directly on the circuit board as much as possible, with fewer IC sockets.

Two, FPC flexible circuit board imposition instructions and methods

1. In the collation process, you can "squeeze" as much as possible under the premise of proofreading.

The so-called "extrusion" is to reduce the distance between adjacent boards, thereby reducing the size of the entire collage, saving production materials, and reducing PCB production costs.

2. The spacing between the veneers is at least 2mm. This is to meet the positioning needs of the positioning holes. In the mass production process, the molding generally adopts the method of die punching to improve the accuracy. For the mold, the collage between each piece In this case, positioning holes must be placed to prevent the mold from deflection, which results in laser cutting and molding. In order to avoid slight deviation and prevent partial and complete deflection, the single pieces cannot be directly connected so that they 22 do not affect each other.

3. The sorting needs to add etching characters, sorting the size, quantity, etc. to make a simple description, so as to facilitate the inspection and calibration in the subsequent production.

4. The four corners of the entire collage are enlarged with positioning holes, and a corner marked with different positioning holes is selected to facilitate the follow-up process to maintain the same direction, so as not to cause the film to be sealed, the word is abandoned, and so on.

PCB industry welcomes growth opportunities

The eastward shift of industry is a unique manifestation of the mainland. The focus of the PCB industry continues to shift to Asia, and the production capacity of the Asian region is further shifted to the mainland, forming a new industrial pattern. With the continuous transfer of production capacity, mainland China has become the region with the highest PCB production capacity in the world.

According to Prismark estimates, China's PCB output value will reach 28.972 billion U.S. dollars in 2018, accounting for more than 50% of global GDP. Data centers and other applications increase the demand for HDI, and the future space for FPC is huge. With the surge in building demand, data centers are developing towards high speed, large capacity, cloud computing and high performance, among which server demand will also increase the overall demand for HDI. The explosive growth of mobile electronic products such as smartphones will also drive the demand for FPC boards. In the development trend of smart and lightweight mobile electronic products, FPC has the advantages of light weight, thin thickness, and bending resistance, which is conducive to its wide application.

The demand for FPC in the smart phone display module, touch module, fingerprint recognition module, side button, power button and other sectors is increasing. "Raw material prices + environmental inspections" are intensively improving, and leading manufacturers welcome the opportunity. The rising prices of raw materials such as copper foil, epoxy resin, and ink in the upstream industry have transmitted cost pressures to PCB manufacturers. At the same time, the central government has vigorously launched environmental protection inspectors, implemented environmental protection policies, cracked down on messy small manufacturers, and exerted cost pressure. In the context of rising raw material prices and weakening of environmental inspectors, the reshuffle of the PCB industry has brought a certain degree of concentration increase. Small manufacturers have weak bargaining power in the downstream and it is difficult to absorb the rise in upstream prices. Small and medium-sized PCB companies will withdraw due to shrinking profit margins and reshuffle in this round of the PCB industry. Leading companies have introduced technologies and capital advantages, which are expected to expand production capacity and merge. With its efficient production technology and excellent cost control, it will directly benefit from the increase in industry concentration.

It is expected that the industry will return to rationality and the industry chain will continue to develop healthily. New applications have promoted the development of the industry, and the 5G era is gradually becoming mature. New 5G communication base stations have a lot of demand for high-frequency circuit boards: Compared with the number of millions of other base stations in the 4G era, the scale of base stations in the 5G era is expected to exceed tens of millions.

High-frequency and high-speed circuit boards that meet 5G requirements have extensive technical barriers and higher gross profit margins than traditional products. The trend of automotive electronics has driven the rapid growth of automotive PCBs. With the deepening of automotive electronics, the demand for automotive PCBs will gradually increase. Compared with traditional vehicles, new energy vehicles have higher requirements for the degree of electronization. The cost of electronic equipment in traditional luxury vehicles accounts for about 25%, and in new energy vehicles, it reaches 45% to 65%. Among them, BMS will become a new growth point for automotive PCBs and put forward a lot of rigidity requirements for millimeter wave radars equipped with high-frequency PCBs.