In recent years, the degree of automation of industrial equipment has become higher and higher, so the number of industrial control boards in various industries has also been increasing. After the industrial control board is damaged, the high cost required to replace the circuit board has also become a very headache for enterprises.EssenceSo, do you know what is the maintenance method of circuit board?What are the maintenance steps of the circuit board?Lets take a look with Xiaobian.
Classification of circuit board
If the line board is divided into three large categories: one -piece panel, double panel, and multi -layer circuit board.
1. Single panel, on the most basic PCB, parts are concentrated on one side, and the wires are concentrated on the other side.Because the wire only appears on one side, it is called this PCB called a single -sided line board.Single panels are usually simple and low in cost, but the disadvantage is that it cannot be applied to too complicated products.
2. Double -panels are the extension of one -eyed panel. When single -layer wiring cannot meet the needs of electronic products, double panels must be used.Both sides have copper covering and wiring, and can be used to drive the line between the two layers through the holes to form the required network connection.
3. Multi -layer board refers to a printed board that has an insulating material with a conductive graphic layer of more than three layers and the insulation material between them, and the conductive graphics intermittently interconnect.Multi -layer line board is the product of the development of electronic information technology towards high speed, multifunctional, large capacity, large -volume, small volume, thin, and lightweight direction.
Circuit boards are divided into soft boards (FPC), hard board (PCB), and hard and hard binding boards (FPCB).
The detection method of circuit board
1. Needle test method
This method is connected to each detection point on the circuit board from a probe with a spring.Spring makes each probe with 100?-? 200g? To ensure that each detection point is well exposed. Such a probe is called a needle bed together.Under the control of the detection software, the detection point and the detection signal can be programmed, and the detectors can know the information of all test points.
2. Observation of circuit board
The circuit board is small and the structure is complicated. Therefore, the observation of the circuit board must also be used for professional observation instruments.Generally, we use a portable video display microscope to observe the structure of the circuit board. Through the video microscopy camera, we can clearly see the micro -structure of the very intuitive circuit board from the microscope.In this way, it is easier to design and detect the circuit board.
3. Dual probe flying needle test method
The flying needle tester does not depend on the insert pattern installed on a fixture or bracket.Based on this system, two or more probes are installed on the X-Y plane that can move freely freely, and the test point is directly controlled by Cadi? Gerber data.The dual probe can move within the range of 4mil.The probe can move independently and does not really limit their degree of approaching each other.Tester with two back -and -forth arm -shaped objects is based on the measurement of capacitors.Press the circuit board on the insulating layer on a metal plate as another metal board of the capacitor.If there is a short circuit between the lines, the capacitor will be larger than a certain point.
Maintenance skills of circuit board
1. Observation method
When we get a circuit board to be repaired, first carefully observe its appearance.If the circuit board has been burned, then before power on the circuit board, be sure to carefully check whether the power circuit is normal, and ensure that it will not cause secondary damage and then power.Observation method is a type of static inspection method. When using the observation method, the following steps are generally followed.
Step 1: Observe whether the circuit board has been artificially damaged;
Step 2: Observe whether the components on the circuit board have been burned;
Step 3: Observe the integrated circuit on the circuit board;
Step 4: Observe whether the wiring on the circuit board is peeling and burning the road.Is there any disconnection from the pads of the copper holes;
Step 5: Observe the insurance on the circuit board (including insurance tube and thermal resistance), see if the fuse is melted.Sometimes because the fuse is too thin and cannot be seen clearly, you can use the auxiliary tool-universal table to determine whether the insurance tube is damaged.
2. Static measurement method
For most circuit boards, problems cannot be found through the previous observation.As long as a small number of circuit boards will cause physical deformation due to some special reasons, and easily find out the cause of the fault. Most of the circuit boards that cause failure need to use the multimeter to have some major components and key points on the circuit board.Preface measurement, find problems, solve problems.
Before the measurement, we must first judge whether the circuit is mainly analog signal or a digital signal.The following only focuses on the static measurement method of the digital circuit, and maintenance mainly follows the following steps.
Step 1: Use a multimeter to check whether the power between the power supply is short -circuited;
Step 2: Use a multimeter to measure the diode to observe whether its work is normal;
Step 3: Use a multimeter resistance file to measure the capacitor to see if there is a short circuit or disconnection. If there is, it means that there is a problem with this part of the circuit.;;
Step 4: Similarly, use a multimeter to measure the integrated circuit, triode, resistance, etc. on the circuit board to see if it meets its own logical performance ... Details >>
TIPS: After the inspection of the observation method and the static measurement method, most of the problems occurred in the circuit board maintenance can be resolved. It is worth noting that the power supply must be ensured.damage.
3. Online measurement method
The online measurement method is generally applied to a manufacturer of batch production circuit boards. In order to facilitate maintenance, manufacturers generally build a relatively common debugging and maintenance platform. It can easily provide the power supply required by the circuit board and some necessary initial signals.The online measurement method mainly solves two aspects.The first is to subdivide the problems found in the previous two steps and finally lock it to the component of the problem.The second is that through the above two -step inspection, the problem is not solved, the cause of the faulty needs to be found through online measurement.The online measurement method is mainly used for the comparison of two good or bad circuit boards. Through comparison, problems are found and problem -solving.

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