PCBA manufacturers detailed circuit board components testing skills

The core of electronic equipment is the circuit board, which is composed of a large number of various types of electronic components. If the equipment fails or short-circuits, most of the reasons will be caused by the failure or damage of electronic components. Next, Shenzhen PCBA processing manufacturer -kingford will introduce the detection skills of circuit board components.

Circuit board components testing skills

1. Measure the polarity of each foot of the rectifier bridge

Multimeter set R×1k block, black pen bridge pile any pin, red pen has measured the rest of the three feet, if the reading is infinite, then the black pen is connected to the bridge pile output positive pole, if the reading is 4 ~ 10kΩ, then the black pen pin is the bridge pile output negative pole, the other two pins for the AC input bridge pile.

2. Judge the quality of crystal vibration

First, use a multimeter (R×10k stop) to measure the resistance values at both ends of the crystal oscillator. If the resistance value is infinite, it indicates that the crystal oscillator has no short circuit or leakage; Then insert the test pen into the mains jack, pinch any pin of the crystal oscillator with your finger, and touch the other pin to the metal part at the top of the test pen. If the neon bubble of the test pen turns red, it indicates that the crystal oscillator is good; If neon bubble is not bright, crystal oscillator is damaged.

3. Unidirectional thyristor detection

Available multimeter R×1k or R×100 block measurement of any pole of the positive and reverse resistance, if find a pair of pole resistance for low resistance value (100Ω ~ lkΩ), then the black watch pen is connected to the control pole, red pen is connected to the cathode, another extremely anode. There are three PN junctions in thyristor. We can judge its quality by measuring the positive and reverse resistance of PN junctions. When measuring the resistance between the control pole (G) and the cathode [C], if the positive and reverse resistances are zero or infinite, it indicates that the control pole is short circuit or open; when measuring the resistance between the control pole (G) and the anode (A), the positive and reverse resistance readings should be large; when measuring the resistance between the anode (A) and the cathode (C), the positive and reverse resistance should be large.

PCBA board

4. Polarity identification of bidirectional thyristor

Bidirectional thyristor has the main electrode 1, the main electrode 2 and the control pole, if the resistance between the two main electrodes is measured with a multimeter R×1k, the reading should be approximately infinite, and the positive and reverse resistance reading between the control pole and any of the main electrodes is only dozens of ohMs. According to this characteristic, we can easily identify the control pole of bidirectional thyristor by measuring the resistance between the electrodes. When the black watch pen is connected to the main electrode 1. The forward resistance measured by the red marker is always smaller than the reverse resistance, according to which we can easily identify the main electrode 1 and 2 by measuring the size of the resistance.

5. Check the quality of the light emitting nixie

The multimeter is set to R×10k or R×l00k, and then the red pen and digital tube (common negative digital tube as an example) of the "ground" leading end is connected, black pen is connected to the other leading end of the digital tube, seven sections should be respectively luminous, otherwise that the digital tube is damaged.

The above is the introduction of the detection skills of circuit board components. Shenzhen kingford is a professional PCBA OEM and material processing manufacturer with its own PCB board factory and SMT patch processing factory. We can provide one-stop services from upstream electronic component procurement to PCB production and processing, SMT patch, DIP plug-in, PCBA testing, finished product assembly and so on.

PCBA processing advantages

1. Highly professional: The company focuses on processing samples and small and medium-sized batches, and promises to deliver the materials within 3-5 working days after confirmation.

2. Professional equipment: The company's equipment is tailored for sample and small and medium-sized batch production of advanced equipment, can stick 0201, BGA spacing 0.3MM, QFN, CSP, CON and other components.

3. Professional technology: 100% of technical backbone workers have more than 5 years of work experience, 85% of front-line operators have more than 3 years of work experience.

4. The company implements the 5S and 6σ concepts in daily operation, so as to ensure that the shipment is checked at least 7 times. If the quantity reaches 100PCS, our company promises to pass AOI optical inspection.

5. The company promises that the straight through rate of welding is more than 99%. If customers find welding defects, the company promises to repair them free of charge.