Repairing printed circuit boards - tips by Exception PCB

PCBs, or printed circuit boards, have revolutionised the electronic industry; however they lack the robustness of the earlier, steel-chassis, hardwired equipment, driving them to be much easier to crack. Restoring a circuit board needs a particular level of analytical ability, along with the skill to handle each element in the correct way.

Without having a thorough knowledge of the way a circuit board works, experts from Exception PCB express that diagnosing the trouble will be a problem. For PCBs that are especially complex, you might also need an oscilloscope to discover signals at different points, so as to discover the section which is creating the problem. Once this component has been discovered, it will then have to be replaced. Here, Exception PCB provides you with a brief guide on how to do this.

As outlined by Exception PCB, with the majority of passive (and occasionally active) components, a similar, as opposed to an exact copy of the broken element can be used as a replacement. You will find, for example, several unique versions of voltage regulators available, and one version can easily be swapped for another in a PCB. However, broken active components that have a very specific function (for example, audio amplifier chips) must be replaced with an exact copy.

After you have acquired the right replacement, you'll have to place the PCB on a flat surface for the fix. Exception flexible PCB says that you might use tape to stick the board on both sides to the surface, to ensure that it doesn't move whilst you are carrying out the replacement. Pull the damaged component off the board very delicately, using tweezers. Next, switch on your soldering iron and set it to about 400 degrees Celsius.

Take some copper wire and put it on the pads of the PCB where the component was, and use the soldering iron to heat it. Wonderful pcb that any surplus solder remaining on these pads could be absorbed by the copper. Get in line the leads of the replacement component with the board's pads, taking a look at to make sure that the element is aligned as it needs to be. Then, use the soldering iron and the solder to join the leads with the corresponding pads on the board.

PCB production process

One,contact the factory
First, the need to contact the PCBA manufacturer, and then registered customer number, then there will be people you quotation, place an order, and follow up the production schedule.
Two, expected to open
Objective: according to the engineering data MI requirements, in compliance with the requirements of the large plate, cut into small pieces production plate. The customer request small plate material requirements.
Process: plate material, edge cutting and grinding to a board to curium plate to beer fillet \according to requirements of MI
Three, drilling
Objective: according to the project information, in accord with the requirements of the opening sheet size, aperture drill position corresponding to the request.
Process: laminated plate pin, upper plate and lower plate, hole drilling, check \ repair
Four, the copper deposition
Objective: the copper deposition is the use of chemical methods in the insulation on the hole wall deposition of a thin layer of copper.
Process: coarse grinding, plate and hanging plate, copper precipitation automatic line, dipping down% dilute H2SO4, thickened copper
Five、 image transfer
Objective: to pattern transfer is the transfer of image from film to plate production
Process: (blue oil flow): grinding plate, printing the first side, drying, printing second surface, drying,exposure to flush the shadow to check; (dry film process): Ma plate to squeeze film, static,alignment and exposure to static, Chong shadow to check
Six, pattern plating
Objective: pattern plating is in line graphics bare copper skin or a hole on the wall of the plating layer of copper layer and the required thickness requirements to the thickness of the gold nickel or tin layer.
Process: on board, degreasing, water washing two times, etching, water washing, pickling, water washing, acid leaching, copper, tin, water washing, the lower plate
Seven, stripping
Objective: plating covered with NaOH solution receded anti film makes the non line copper layer is exposed.
Process: water film: inserting frames, alkali, washing and scrubbing, machine; dry film: board,machine
Eight, etching
Objective: etching is the use of chemical reaction to the copper layer corrosion non line parts.
Nine, the green
Objective: to transfer the green is green film graphics to the plate, to protect the line and stop line tin welding parts function
Process: grinding plate, printing photosensitive green to curium plate, exposure to Chong Ying;grinding plate, Indy side - drying plate to print second surface - drying plate
Ten, character
Objective: the character is an easy to recognize markers offers
Process: the green end curium, cooling static, adjusting net, seal character, curium
Eleven, gold finger
Objective: plating requires a layer thickness in the plug on the finger nickel \ gold layer, the wear resistance is more hardness
Process: on board, degreasing, water washing two times, etching, washed two times with water, acid pickling, water washing, copper plating, nickel plating, washing, gold-plated
Tin plate (a process parallel)
Objective: spray tin in the bare copper surface not covered on the solder oil spray a layer of tin,copper surface to protect non corrosion oxidation, so as to ensure the good welding performance.
Process: Micro etching, air drying, preheating, rosin, solder coated, hot air leveling coating, air cooling, washing drying
Twelve, forming
Objective: through mould pressing or milling machine gong out of shape forming method customer needs organic gongs, beer plate, hand gongs, hand cut
Note: Data gong machine plate and punching board and precise, hand gongs secondly, hand cut board lowest with can only do some simple shapes.
Thirteen, test
Objective: through 100% electronic testing, detecting visual is not easy to find to open circuit, short circuit etc. the influence of functional defects.
Process: the die, board, testing, qualified to FQC visual inspection, unqualified to repair, back testing, OK - REJ - Scrap
Fourteen, final inspection
Objective: through the appearance defects of 100% visual inspection panel, and the slight defect repair, avoid the problems and defects in plate out.
Specific work process: incoming to view the data, visual inspection, qualified, FQA checks, qualified,unqualified and packaging, processing, check OK

How to get more and more orders from customers

In today's condition of information explosion, the business is more and more difficult. Especially in the global financial crisis period, feelings will be deeper. Therefore, in this adverse environment and more fierce competition, how to get orders is very important.
Try to improve overall quality, the higher of the overall quality, the more appealing.
We often encounter a situation: on the same question, someone will find very excellent answer, his clarity, logic, feasibility are all above the crowd. Why? Because of the high overall quality. Therefore, We must pay attention to learning, attention to the accumulation of experience, attention to learn from the experience, pay attention to constantly improve our self-serving to speak and act. As the saying goes: "do business must first learn how to be a good man",  in fact, it is not only integrity, more important is to have a high ideological and cultural taste. So when in contact with the customer, it will make people feel your outstanding, they will admire and believe you before do business with you. Thus, after several contacts and then the customer and you will tend to become friends, and slowly became "buddies child." Then there will be a lot of business after that.
Written by Shirley Xia from Wonderful PCB company

Printed Circuit Board

   Single side pcb
Single-Sided Boards we have just mentioned, at the most basic PCB, parts focused on one side, the wires are concentrated on the other side. Because the wire only in one side, so we call this PCB is called a single panel (Single-sided). Because there are many single panel strict limits on the design line (because only one side, and between the wiring alone can not cross * path must be around), so only the early use of such a circuit board only.
  Double-sided pcb
Double-Sided Boards This board has wiring. However, to use the wire on both sides, must be between the two sides have the proper electrical connections for the job. This circuit between a "bridge" called pilot hole (via). The guide hole in the PCB, metal filled or coated with a hole, which can be connected to the wire on both sides. Because the double-sided single-panel area than twice as big, and because the wiring can be interleaved with each other (you can go around the other side), it is more suitable for use in more than one panel
  Mulity layer PCB
[MLB] plywood when more complex application requirements, can be arranged in a Multilayer PCB structure and pressed together, and in the inter-layer connectivity provisioning through-hole circuit layers of circuitry. Inner line CCL first crop to fit the size of the production process. Before first use the substrate film usually requires brushing, micro-etching method such as a copper foil to make the appropriate plate surface roughening treatment, and then the appropriate temperature and pressure to the dry film resist is attached on the adhesion. After the polymerization reaction will produce a good dry film photoresist substrate paste into UV exposure machine, exposure, photoresist film by ultraviolet radiation transmittance in the region (the region will be dry later developed, copper etching step is retained as an etch resist), and the line image on the film over to the dry film photoresist on the board. Remove the protective film after the surface of the membrane, the first area of the membrane to the surface of the aqueous sodium carbonate developer removing unlit, mixed with hydrochloric acid and hydrogen peroxide solution out of the exposed copper is removed by etching to form a line. Finally, mission accomplished with aqueous sodium hydroxide wash dry film photoresist removed. For the six (or more) of the inner layer circuit board with automatic positioning punching machine out of the inter-layer circuit alignment riveting reference hole.
Sophie Deng
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Wonderful PCB Limited
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1.Booth: 9J35, HK Global sources Oct.12-15th,2013 Asia World-Expo, Hong Kong
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