As long as it is the ground, it must be connected together in the end, and then enter the earth. If they are not connected together, they will be “floating”, and there will be a voltage difference, which will easily accumulate charges and cause static electricity. The ground is referenced to 0 potential, and all voltages are obtained with reference to the ground. The ground standards must be consistent, so the various grounds should be shorted together. The earth is believed to absorb all charges, remain stable at all times, and is the ultimate ground reference point. Although some boards are not connected to the ground, the power plant is connected to the ground, and the power on the board will eventually return to the power plant and be grounded. If the analog ground and the digital ground are directly connected in a large area, it will cause mutual interference.today qihe smt pick and place smt machine line will sharing you There are four ways to solve this problem: 1. Connect with magnetic beads; 2. Connect with capacitors; 3. Connect with inductance; 4. Connect with 0 ohm resistors.
Single-point grounding of analog ground and digital ground
The equivalent circuit of the magnetic bead is equivalent to a band-resistance wave limiter, which can only significantly suppress the noise at a certain frequency point. When using it, it is necessary to estimate the frequency of the noise point in advance in order to select an appropriate model. For the situation where the frequency is uncertain or unpredictable, the magnetic beads are not compatible; the capacitor is directly connected to the traffic, causing floating ground; the inductor is large in size, has many stray parameters, and is unstable; the 0 ohm resistance is equivalent to a very narrow current path, which can effectively limit loop current so that noise is suppressed. Resistors have an attenuation effect on all frequency bands (0 ohm resistors also have impedance), which is stronger than magnetic beads.
For current loops when crossed
When the electrical ground plane is divided, the shortest return path of the signal is broken. At this time, the signal loop has to be detoured, forming a large loop area, and the influence of the electric field and magnetic field becomes stronger, and it is easy to interfere/be interfered. Connecting a 0 ohm resistor across the partition can provide a shorter return path and reduce interference.
Generally, jumpers and DIP switches should not appear on the product. Sometimes users will fiddle with the settings, which can easily cause misunderstandings. In order to reduce maintenance costs, 0 ohm resistors are used instead of jumpers and soldered on the board. The vacant jumper is equivalent to an antenna at high frequencies, and the effect of using chip resistors is good.
Cross-line debugging/testing during wiring: At the beginning of the design, a resistor needs to be connected in series for debugging, but the specific value cannot be determined. After adding such a device, it is convenient for future circuit debugging. If the debugging result does not need to add a resistor , add a 0 ohm resistor. Temporarily replacing other SMD devices as temperature compensation devices is more often due to the need for EMC countermeasures. In addition, the 0 ohm resistance is smaller than the parasitic inductance of the via, and the via will also affect the ground plane (because of the need to dig holes).
There is no function in the circuit, it is only on the PCB for debugging convenience or compatible design and other reasons.
Can be used as a jumper, if a certain line is not used, just paste the resistor directly (does not affect the appearance)
When the parameters of the matching circuit are uncertain, replace them with 0 ohms. During actual debugging, determine the parameters and replace them with components of specific values.
When you want to measure the current consumption of a certain part of the circuit, you can remove the 0 ohm resistor and connect an ammeter, which is convenient for measuring the current consumption.
When wiring, if you really can’t pass it, you can also add a 0 ohm resistor.
Under high-frequency signals, it acts as an inductor or capacitor (related to the characteristics of the external circuit), mainly to solve EMC problems. Such as ground and ground, between power supply and IC Pin.
Single-point grounding (meaning that the protective grounding, working grounding, and DC grounding are separated from each other on the equipment, and each becomes an independent system).
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What is SMT in engineering?
Surface mount technology is a part of the electronic assembly that deals with the mounting of electronic components to the surface of a PCB. Electronic components mounted this way are called surface-mounted devices (SMD). SMT was developed to minimize manufacturing costs while making efficient use of board space.Qihe SMT company develops and produces all kinds of SMT equipment suitable for world wide market, including pnp machine,reflow oven,stencil printer,pcb handling machines,and other products.
Small desktop pick and place machine TVM802A,TVM802B,TVM802AX,TVM802BX series suitable for beginners, for hobbiest or low vol usag.
Advanced level 4-head LED strip placement QL41 led machines and with rail universal series TVM925S,TVM926S,
Fully automatic 6-10-head placement QM61,QM62,QM81,QM10,machines, which are suitable for high volume mass production in factories.
What is SMT in programming?
Offline Automated Programming vs Inline SMT Programming
Qihe pick and place machine can be programmed directly on the SMT equipment .
Or Coordinates can also be imported csv file through programming software.
Currently supported software such as protel,DXP,Altium Designer,Pads,Candes,proteus,DXP.
Inline SMT programming is a solution to consider for narrow segments of device programming requiring short programming times, with medium to high volume, for just one device type.
WHAT IS SMT pick and place machine？
SMT (Surface Mounted Technology) is a comprehensive system engineering technology, which covers substrates, design, equipment, components, assembly processes, production accessories and management. When it comes to SMT pick and place machines, the automatic SMT production line requires automatic loading and unloading machine, automatic solder paste printing machine, placement machine, reflow soldering machine, AOI inspection equipment, conveyor,connecting table, etc. For these SMT assembly line equipment, Qihe SMT can offer you machines in prototype SMT line, small SMT production line, mass production SMT line at low SMT line cost. Contact us now if you are interested.
WHAT IS SMT ASSEMBLY LINE？
With the development of technology, future electronic products will be lighter, smaller and thinner. Traditional assembly technology can no longer meet the requirements of high-precision and high-density assembly. A new type of PCB assembly technology-SMT (Surface Mount Technology) has emerged. SMT Assembly is the use of automated machines to assemble electronic components on the surface of the circuit board. Its density, high speed, standardization and other characteristics occupies an absolute advantage in the field of circuit assembly technology. In addition, SMT assembly has a wide range of uses.