CNC machine tools are the products of high-tech applications such as integrated application computer, automatic control, automatic detection and precision machinery. They are typical mechatronics processing equipment with high technology intensity and high degree of automation. Compared with ordinary machine tools, its superiority is obvious. Not only the high precision of parts processing, the product quality is stable, but also the degree of automation is extremely high, which can reduce the physical labor intensity of workers and greatly improve the production efficiency, especially worth mentioning. CNC machine tools can complete the machining of parts with complex curved surfaces that are difficult or impossible to machine with ordinary machine tools. Therefore, the position of CNC machine tools in the mechanical manufacturing industry is becoming more and more important. However, we must be soberly aware that whether we can achieve the advantages described above for CNC machine tools depends on whether the operators can use them properly and correctly in production. From the operator's point of view, we should talk about the matters that should be paid attention to in the use of CNC machine tools to ensure that the superiority of CNC machine tools can be fully utilized. 1. Improve the overall quality of the operator The use of CNC machine tools is more difficult than the use of ordinary machine tools, because CNC machine tools are typical mechatronic products, which involve a wide range of knowledge, that is, the operator should have machine, electricity, liquid With a wider range of expertise, such as gas, the quality requirements for operators are very high. At present, a phenomenon that cannot be ignored is that there are more and more users of CNC machine tools, but the utilization rate of machine tools is not high. Of course, sometimes the production tasks are not full, but there is a more critical factor that the quality of CNC operators is not high enough. I don’t know how to deal with some problems, especially the newly purchased machine tools. Due to the quality problems of electronic components and the vibrations in transportation, some faults appear in the CNC system within 3 to 6 months after the official production. It is not found in the maintenance manual, and it may never have been encountered before. This requires the user to have higher quality, be able to calmly deal with the problem, be clear-headed, have strong judgment on the spot, and of course should have a solid CNC. Basics, etc. Under normal circumstances, the machine tool manufacturers will provide users with technical training opportunities when purchasing new machine tools. Although the time is not long, they are highly targeted, and users should pay attention to them. The personnel should be included in the future machine operators. The improvement of the overall quality of operators is not a one-off event, but it must be sustained for a long time. It should be accumulated in the future use. There is also a way to try to visit some old users of similar machine tools. They have strong practice. Experience, the most able to speak, can ask for their help, let them carry out certain training for the operator, which is the most effective way to improve the overall quality of the operator in a short time. 2. Follow the correct operating procedures No matter what machine, it has its own operating procedures. It is not only one of the important measures to ensure the safety of operators, but also an important measure to ensure equipment safety and product quality. The user must operate correctly according to the operating procedures. If the machine is used for the first time or not used for a long time, let it idle for a few minutes. Pay attention to the sequence of power-on and power-off and precautions during use (such as manual or use after power on) Program instructions automatically refer to the point of reference), these should be paid enough attention to beginners, because they lack the corresponding operational training, and often make mistakes in this regard. 3. Create a good environment for use With the advancement of science and technology, in general, the use environment of CNC machine tools has no harsh requirements, and can be placed in the same production workshop as ordinary machine tools. That being said, since CNC machine tools contain a large number of electronic components, they are most afraid of direct sunlight, and are also afraid of moisture, dust, vibration, etc., which can cause electronic components to be corroded or cause short circuits between components, causing The machine is not working properly. These are usually taken care of when installing the machine. For the user, the main concern is the protection of the surrounding environment. For example, when it is raining, it is necessary to take care not to bring the umbrella to the production site and replace the shoes. After the purchase of CNC machine tools, if its starting rate is not high, this will not only make the funds invested by the users not play a role in reproduction, but also a worrying problem is that it is likely to be over-warranty, equipment failures need to pay extra The maintenance cost, because the newly purchased equipment has a certain period of warranty period, from the past experience, the initial failure rate of CNC equipment is relatively large in the initial use, the user should make full use of the machine tool during this period, so that The weak links are exposed as early as possible and can be resolved during the warranty period. Usually lack of production tasks, can not be idle, this is not the love of equipment, but because of long-term use, may accelerate the deterioration or damage of electronic components due to damp and other reasons. The user should be energized regularly, and each time the air is run for about 1 hour, the heat generated by the machine tool can be used to remove or reduce the humidity inside the machine. Inevitably, some faults will occur in the use of the machine tool. At this time, the operator should be treated calmly and should not be handled blindly, so as to avoid more serious consequences. It is necessary to pay attention to the site and wait for the maintenance personnel to truthfully explain the situation before and after the failure. Participate in joint analysis of problems and troubleshoot as early as possible. If the fault is caused by the operation, the operator should learn from the experience in time to avoid repeating the mistake.
Impedance control has been one of the essential concerns and tough problems in high-speed PCB design. Impedance is the sum of the resistance and reactance of an electrical circuit. The resistance being the opposition to current flow present in all materials. In high frequency applications, controlled impedance helps us ensure that signals are not degraded as they route around a PCB. Resistance and reactance of an electrical circuit have a major impact on functionality, as certain processes must be completed before others to ensure proper operation.
Impedance control technologies are quite important in high-speed digital circuit design in which effective methods must be adopted to ensure the excellent performance of high-speed PCB. The impedance of a PCB is largely determined by some factors, such as trace width, copper thickness, dielectric thickness, dielectric constant. Impedance, generally measured in Ohms. We must control the resistance and reactance of an electrical circuit to ensure the quality of signal in the complex design. For example single-ended impedance 50 ohm ±10%, differential impedance 100ohm ±10%.
Electrical Impedance: A measure of opposition to time-varying electric current in an electric circuit.
Impedance Control PCB is too complicated? No worry! JHYPCB engineers can help you at any time as we have three shifts. Free stack-up and impedance calculations can be offered upon request. We will work with your engineering team at the conceptual level of the PCB design to assist you to get better results in controlling impedance by choosing the suitable laminate and layer stack up.
Why Impedance Control PCB can be shipped timely all the time? As common materials are stored well in JHY PCB warehouse regularly. We have heavy copper thickness, 2oz, 3oz or more. Odd copper thickness H/1 oz, H/2 oz, 1/2 oz. Foil: 1/4 oz, H oz, 1 oz, 2 oz, 3 oz.
If you need order Impedance Control PCB, just make notes in Readme file, and send it together with Gerber, our engineer will take care of it. Have a try!
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What PCB designer Must Know About Impedance Control PCB
Controlled Impedance PCB Meaning
Because of complex processors, USB devices and antennas are printed directly on the circuit board surface. The speed of signal switching on the circuit board increases, and the electrical characteristics of the tracks that transmit signals between devices become more and more important. Therefore, more and more PCB designs need impedance control and testing.
When to Use Controlled Impedance
When a signal must have a particular impedance in order to function properly, controlled impedance should be used. In high frequency applications matching the impedance of PCB traces is important in maintaining data integrity and signal clarity. If the impedance of the PCB trace connecting two components does not match the components` characteristic impedance, there may be increased switching times within the device or the circuit. There may also be random errors.
Please note that we also need special instructions here: In DC circuits there is no reactance and the resistance of copper conductors is typically insignificant. However in high speed AC circuits (those with sharp changes in voltage and/or current) the reactance and thus the impedance can become very significant. This can become critical to a design's functionality because of the effects that changes in the impedance along the signals path from transmitter to receiver will have on the efficiency of power transfer as well as signal integrity. While a circuit`s speed is often expressed as the frequency of the wave form: the critical concern is the speed at which the voltage and/or current is required to change.
What Determines Controlled Impedance?
The characteristic impedance of a PCB trace is typically determined by its inductive and capacitive reactance, resistance, and conductance. These factors are a function of the physical dimensions of the trace, the dielectric constant of the PCB substrate material, and dielectric thickness. Typically PCB trace impedance can range from 25 to 125 ohms. The impedance value generated from the PCB structure will be determined by the following factors:
– Width and thickness of the copper signal trace (top and bottom)
– Thickness of the core or prepreg material on either side of the copper trace
– Dielectric constant of the core and prepreg material
– Distance from other copper features
Impedance Control In PCB Design
The Problem: "A", "B" and "C" signals all reach the component at the same time.
The Solution: Apply Impedance to Circuit "C" to slow the signal enough for the component to first calculate ("A"+B").
Similar with a cable, the signal encounters a change of impedance arising from a change in material or geometry. Part of the signal will be reflected and part transmitted. These reflections are likely to cause aberrations on the signal which may degrade circuit performance (e.g. low gain, noise and random errors). In practice, board designers will specify impedance values and tolerances for board traces and rely on the PCB manufacturer to conform to the specification.
When rise times continue to reduce, inevitability the number of traces requiring impedance control will continue to increase. Where impedance control is needed it is important to control it accurately, calculating it with the most representative cross-section we can create.
Applications of Controlled Impedance
Controlled Impedance should be considered for PCBs used in fast digital applications such as:
– Telecommunications
– Computing 100MHz and above
– High Quality Analog Video
– Signal Processing
– RF Communication
Impedance Control PCB Manufacturing
In order to meet the growing demand of impedance control PCB, PCB manufacturers have invested a lot of money and manpower and material resources in production technology, in order to meet the production requirements of customers.
Due to the difficulty of impedance control PCB production, PCB manufacturers generally require PCB designers or purchasers to provide more detailed information and requirements, such as the type of material required, copper weight and thickness of the board, the number of layers, gerber file, so that the manufacturer can prepare the bill of materials (BOM). Impedance information should be clearly marked in Gerber file. If the necessary information is lacking, even a little key information will make it difficult or impossible for the manufacturer's engineers to know exactly what the customer needs.
Impedance-controlled PCBs are also divided into three different situations:
No Impedance Control: This is a situation where you do not need any extra design elements to ensure correct impedance because you have very loose impedance tolerance. Naturally, this will result in a faster-completed, less expensive board because the manufacturer does not have to include any special measures.
Impedance Watching: What is impedance watching? This is a situation where the designer will outline the impedance control trace and the PCB provider adjusts the trace width and dielectric height accordingly. Once the manufacturer approves these specifications, they can begin to manufacture the board. You can request a Time Domain Reflectometry (TDR) test to confirm the impedance for a fee.
Impedance Control: Actual impedance control is something you will typically only request when your design has tight impedance tolerances that could be tough to hit the first time around. When the capability limits of the manufacturer get close to the dimension requirements, it can be tough to ensure target impedance on the initial attempt.
In the case of impedance control, the manufacturer makes the circuit board achieve the target impedance as far as possible. Then they tested TDR to see if they succeeded. If not, they adjust accordingly and try again until they reach the required impedance.
Impedance Control PCB Fabricator