Interpretation of the process principle of each production process of PCB board - molding, electrical testing

Pcb proofing, small and medium batch production experts
PCB circuit board production process

Cutting - inner layer graphics - lamination - drilling - electroplating - outer layer - solder mask - surface treatment - forming - electrical testing - FQC - FQA - packaging - finished product





forming





principle:

The data (strap) is input into the CNC milling machine, and the PNL plate after the imposition is divided (the slab) into the dimensions required by the customer.



Production Process:


Drilling positioning hole - upper plate - input data - seesaw - cleaning the finished board - the next process



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Electrical test





purpose:

PCB electrical performance testing, often referred to as "on", "off" test or "on", "short" road test, to verify the production of the PCB board network state, whether it meets the original PCB design requirements.





principle:

Connectivity test: Apply current to one end of a network to be tested, measure at the other end of the network, and determine whether the network (wire) is conducting, resistor, or disconnected based on the change in current.

Insulation test: A voltage is applied to a network to be tested (wire), and a voltage value is detected on other adjacent networks to determine whether the network (wire) is insulated.





Test classification:

Electrical performance test: contact test, non-contact test



Contact test: Jig test (universal needle bed test, special needle bed test), no jig test (mobile probe test / flying probe, universal no-clamp test / UFT)

Non-contact test: electron beam test, ion beam test, photoelectric test, laser test



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China Hardware Business Network


Http://news.chinawj.com.cn Interpretation of the process principle of each production process of PCB board - molding, electrical testing Editor: (Hardware Business Network Information Center) http://news.chinawj.com.cn Interpretation of the process principle of each production process of PCB board - molding, electrical testing

Automobile Engine Parts

Car engines are designed around sealed, resilient metal cylinders. Most modern vehicles have between four and eight cylinders, though some vehicles can have as many as sixteen! The cylinders are made to open and close at precisely the correct time to bring in fuel to combine with the spark for burning internally, and to release the exhaust gases produced. While there are several components on an engine, we`ve compiled a list of the most essential car engine parts and their functions, that power your vehicle. Refer to the diagram to locate where they reside on your engine.

Engine valve – This is the very core of the engine. Often made of aluminum or iron, it has several holes to contain the cylinders as well as provide water and oil flow paths to cool and lubricate the engine. Oil paths are narrower than the water flow paths. The engine block also houses the pistons, crankshaft, camshaft, and between four and twelve cylinders-depending on the vehicle, in a line, also known as inline, flat or in the shape of a V.


Pistons – Are a cylindrical apparatus with a flat surface on top. The role of the piston is to transfer energy created from combustion to the crankshaft to propel the vehicle. Pistons travel up and down within the cylinder twice during each rotation of the crankshaft. Pistons on engines that rotate at 1250 RPM, will travel up and down 2500 times per minute. Inside the piston, lie piston rings that are made to help create compression and reduce the friction from the constant rubbing of the cylinder.


Connecting Rod – Attached to the engine through cylinder bolts, sealed with the head gasket. The cylinder head contains many items including the valve springs, valves, lifters, pushrods, rockers, and camshafts to control passageways that allow flow of intake air into the cylinders during the intake stroke as well as exhaust passages that remove exhaust gases during the exhaust stroke.
Timing Belt/Chain – The camshaft and crankshafts are synchronized to ensure the precise timing in order for the engine to run properly. The belt is made of a heavy-duty rubber with cogs to grasp the pulleys from the camshaft and crankshaft. The chain, similar to your bicycle chain wraps around pulleys with teeth.

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