PCBQuick FAQ

1、What’s Needed For Turn-Key Quotes And Orders?Why do we need your BOM list? In order to accurately quote your assembly, we need to know what parts we are placing on your PCB’s.  This will ensure you get the best possible price for your assembly without any re-quoting! 2、What Does Your Quoted Price For PCB Boards Include? The PCB price includes board cost (unit price*qty), setup cost, electrical test cost.There are two kinds of electrical test methods. One is flying probe e-test, the other one is fixture e-test.You can choose the suitable method according to order size and frequency. (Less 0.2 sq.meter, the sample include a flying test.) 3、 Can You Offer If We Only Provide PDF File Or No File? Yes, we can provide you the estimated price, only if you tell us the board thickness, solder mask color, technics requirements and quantity. 4、 Should I Send You My Files Again When Re-Ordering? Q: I want to re-order PCB which you have manufactured for me before, should I sent you my files again?A: I don’t change Gerber file, only send re-order PO. (Usually, re-order Min QTY above 3sq/m2)  5、 Are My Design Files Safe When I Submit Them To You For Manufacturing? We respect customer’s copyright and will never manufacture PCBs for someone else with your files unless we receive written permission from you, nor we’ll share these files with any other 3rd parties.

1、what are the details about packing and delivery time? For small packages, we will ship the boards to you by DHL, UPS, or EMS. The door to door service, you can get your PCBs at home. For heavy goods more than 300kg, we will ship them out by sea or by air. You can save on freight cost. Of course, if you have your own forwarder, we may contact them dealing with your shipment. And we use vacuum packaging. 2、Can I Request Quotes From This Website? Yes, PCBQuick provides our customers with a powerful and easy-to-use online service for requesting quotes.   3、What Shall I Do When I Find Problems With The PCBs Supplied By You? 1) If you have problems with PCBs supplied by us, please contact the correspondent sales  engineer within 30 days upon receiving the goods and provide the following documents:a. Filled Customer Complaint Form.b. Sending us to defect PCB pictures by e-mail. ( sometimes defect PCBs need sending back to us)2) PCBQuick’s QA engineer will review our request and if the PCBs are non-conforming with customer specifications or IPC-A-600, IPC  IPC-A-610 class 2, we will process your request.3) With your approval of the problem and reproduce the PCBs, there is no additional charge. WHAT CAN WE DO BETTER? We offer low-cost ROHS compliant PCB prototypes with Immersion gold surface finish.We allow multiple boards to be put on the same panel.We will penalize many different PCB files on one panel for your free of charge.Our minimum order is 1 panel.We do free Design Rule Check and notify you if we find that your design violates our technological requirements or have errors.We produce and ship in 3-5 working days after we receive your order confirmation.We can do quick turn service for sample: 24hours,48hours,96hours in our production.

1、What’s The Maximum Supply You Can Supply? 100000 Square Meter per Month ALU LED MCPCB 2、 What Kind Of Products Are More Popular In Your Company? Such as double-sided board, multilayer board, and aluminum board. 3、 What Is The PCIe 2 Gen Golden Finger Plating Gold Thickness (Um)? 0.8um is the standard(IPC Class2) for all gold figure board 4、 WHAT’S A BOM? A BOM is a Bill of Materials that list the components required to build your project.  BOM’s include Part Number, reference designators, quantity, and description of parts that need to be assembled.  5、 Are Your Prototypes Built Same As Production? Yes. Our prototypes (Standard Spec) use the same premier production (Custom Spec) processes as our production (Custom Spec) circuit boards 6、 I Have An Urgent Order (24 Hours Working Time), Can You Do Double Sided Solder Mask And Overlay? Yes, we can do double sided solder mask and overlay including nonstandard colors, copper weights, and material thickness in 24 hours.Some nonstandard materials may take longer to the source. If you will need a board made in 24hrs that needs a special material let us know in advance so we can get the material beforehand. 7、 Can You Produce The Boards If I Only Provide The PCB Sample, Not PCB File? Sure. You can deliver the PCB sample to us, and we clone the PCB design, then produce the boards for you. 8、 How Do You Control The Quality? All boards must pass the test equipment and provide test reports.Sometimes the quick-turn service boards don’t include the report. If needed, please contact the sales, they will send to you. 9、 What Kind Of PCB File Format Can You Accept For Production? GERGER, PROTEL 99SE, PROTEL DXP, POWER PCB, CAM350, GCCAM, ODB+(.TGZ) 10、What Is Your Minimum Order Quantity For First Production? There is no MOQ limit for a new order. One piece or one panel is okay. 11、What’s Your Advantage Of LED PCBs Comparing With Other Pcb Manufacturers? 1). As per your LED PCBs files to production. The same as another factory.2). If no file, you have the LED PCBs, we can copy as per the samples you provided, also we provide the BOM list.3). We can produce PCB as per your schematic design. If you need, we can do assembly and tested, and you can get finished products 12、What Kind Of LED PCBs Can You Make? Our LED PCBs include aluminum PCBs for LED lights(T8, T5), FR4 PCBs for LED Driver, FPC LED PCBs for Lex LED Strip. Such as round aluminum PCBs for spotlights, strip aluminum PCBs for LED tubes and so on. 13、What Is Your Testing Policy? All PCBs are 100% electrical tested. 14、Do You Accept PCB Design With Different Boards On The Same Panel. Yes, we can do different boards in one panel. 15、Can You Manufacture On High-Frequency Materials As TG170, Rogers Etc? Yes, we can. but we don’t stock such materials.

1, How About Your Quality Management System? A set of strict and perfect quality management system with well-trained operating staff is available in the group.The Company had passed:ISO 9001:2008 certificationISO 14001:2004 certification We control every production step:quality assurance engineering - - central quality assurance integration - incoming quality control - in-process quality control - outgoing quality control. 2, How Long Can I Keep The PCB In Stocking Before Using It? 1). Immersion gold PCB, it can be kept in 6 months.2). Immersion silver or tin PCB, it had better not keep them more than 3 months.3). HAL or HAL Lead-free PCB, it can be kept more than 6 months, but not over one year.Please note the circuit boards must be packed in a vacuum package and kept in the warehouse at 25+/-3 degree temperature and humidity 65%. 3, If I Found Problems With The PCBs Supplied By You, What Shall I Do? 1) If you have problems with PCBs supplied by us, please contact the correspondent sales engineer within 30 days upon receiving the goods and provide the following documents:a. Filled Customer Complaint Form.b. Sending us to defect PCB pictures by e-mail. (sometimes defects need to be returned to us)2) PCBQuick‘s QA and engineer will review our request and if the PCBs are non-conforming with customer specifications or IPC-A-600, IPC IPC-A-610 class 2, we will process your request.3) With your approval of the problem and reproduce the PCBs, there is no additional charge. 4，How to compensate and return when quality problem occurs？ Dissatisfaction does occur from time to time. In case our PCB or assembled boards are not usable due to our fault, you can ask for compensation. We can refund to your account directly or credit your PCBQuick account, these credits are available to pay for your next orders with us. We can also rework the unusable boards or re-fabricate your PCB and re-ship to you at our cost, but please cooperate to solve the problem if need to rework.

Solder Mask 1, What Are The Colors Of PCB ResistanceWelding? Green, and other blue, black, red, white and unhindered welding. 2, What About The Color Of Solder Mask? Commonly used is green, and blue, black, white and orange, but we also use gray. 3, What Solder mask Colors Are AvailableFor My PCBs? We can offer black, blue, red, green, yellow and white solder masks for production orders. 4, Is It Possible Top And Bottom Solder masks To Be Different, Does This Involve Additional Charge? Yes, on the double sided boards we print two soldermasks on top and bottom copper layers and the soldermask may be different (SMT parts) and this doesn't involve additional charge.  5, How Many Solder masks Are Printed On TheSingle Sided PCBs? We print one solder mask on the copper layer of your single sided boards. It may be on top or bottom depending on where is your  copper layer. 6, Will I Get Discount On My Prototype If I ask You To Make It Without solder mask? No, in matter of fact our PCB finish is immersion gold, which means if your board is manufactured without solder mask it will lead to solid gold deposit on your exposed copper area and your price will be MUCH higher than our standard panel price, if your design  requires absence of solder mask (RF parts, terminal dissipation) please ask for special quote - we can’t offer you our standard prices  for PCBs without solder mask. Laminate Thickness 1, What Laminate Do You Usually Use For Your PCB Products? We can manufacture your boards also with these non-standard laminate thickness: 0.5 mm (0.020”), 0.8 mm (0.032”), 1.0 mm (0.04”). Special thickness:0.2mm(0.008”),2.0mm(0.08”)  2, Can You Offer If We Only Provide PDF File Or No File? Professional manufacturer of asphalt machines. Our sales and R&D team have over 10 years’ experience to focus on asphalt distributor, synchronous pavement surface vehicles and other road machinery and equipment. Based on innovation 3, What’s Your Standard Of Copper Thickness? 1) The finished copper thickness meets customers’ requirement.2) The whole copper thickness is 25um. Even if there is no need 25um, please note that our production still keeps the hole copper thickness as per 25um standard. Copper Thickness 1, How much copper can be done in a single side printed circuit board? PCBQuick conventional copper thickness: 17 um,35 um,70 um,105 umSpecial copper thickness: 175 um, 245 um of TG170 material 2, What’s Your Standard Of Copper Thickness? 1) The finished copper thickness meets customers’ requirement.2) The whole copper thickness is 25um. Even if there is no need 25um, please note that our production still keeps the hole copper thickness as per 25um standard. 3, What Copper Thickness Option Do I Have? We can offer 18 um (1/2 oz) ,35 um (1 oz) ,70 um( 2oz) and 105 um(3oz) copper thickness. PCB Stenci 1, What Is The Fiducial Point? Do I Need Them On My PCB Stencil? Fiducial are alignment marks made up of 1mm PADs surrounded by a 2mm gap. If your screen printer is equipped with a vision system, the fiducial of the half-mold cutting stencil will allow the printer to automatically align the stencil and screen. If you are manually aligning the stencil, you can cut the fiducial completely through the stencil, or use any surface mount pad to align the stencil. 2, How Do I Select The Thickness Of PCB Stencil? The thickness of the PCB stencil is determined by the smallest component pad in the PCB. The conventional thickness of 0.12mm, PCB spacing of the IC is small and there are many BGA, PCBQuick recommended 0.1mm thickness; If you are not sure, our engineers will choose the best thickness for your circuit board. 3, Why Do I Need A PCB Stencil? The PCB stencil instead of surface mount components of the manual welding to avoid inconsistencies caused by manual welding; they allow the solder paste directly into the surface welding

In determining the bare printed circuit board assembly cost, this involves the price, quality, and delivery time of the raw materials, which focuses on their type and thickness, PCB size, and layer count. Raw Material Type and Thickness When it comes to PCB types, there are two different types such as rigid PCB and flex PCB. Flexible PCB assembly’s cost is more expensive compared to the rigid PCB board. For the latter, many material types may be available for use to produce a PCB. The most basic is called FR-4. FR-4 consists of a fiberglass and material combined together with an epoxy resin known for its fire-resistant features. Other types include higher temperature FR-4, polyimide, hybrid capable, high copper weight, and flex PCBs that may be chosen to produce high copper weight, hybrid capable PCBs or other types. In general, the most basic material thickness is 0.062-inch. The careful selection of the different material types and thicknesses has a critical effect on the manufacturer’s PCBA price. Board Size The printed circuit board’s size is a huge factor that contributes to the PCB assembly services’ production cost. A bigger board size means you need more raw materials to use. This is a vital factor that can impact the overall cost of printed circuit board assembly production. In some instances, based on the client’s specifications, the PCB is built in distinct requirements and this can be costly. In most cases, one dimension is better compared to the other. At times, clients are very particular about their panel requirements. A panel is a larger printed circuit board that has many mini boards that should be divided before using them. Automated printed circuit board handling equipment usually encounters issues with smaller boards, especially when putting several boards together at once, although the process can speed up if necessary. A panel is a vital raw material to create a printed circuit board assembly. The printed circuit board size or the space of the “real estate” it employs up on a panel is a significant factor in estimating the cost/price. It may look simple but, in reality, it can be a complicated thing. For instance, although the dimensions require a PCB that uses less real estate, it may be higher in cost when producing it. The reason behind is the overall panel size needed to manufacture the board. One dimension is more suitable for one panel compared to the other. Let’s take an example, we have two parts with exactly similar total square inches per board. The first is 2-inch x 6-inch while the second is 3-inch x 4-inch. A standard production panel for a PCBA can have more of the 3-inch x 4-inch board as compared to the 2-inch x 6-inch board. So the cost per board would be reduced in the 3-inch x 4-inch board. Layer Count The number of layers is a cost-determining factor. Single-sided or double-sided PCBAs are of the same cost to produce. However, multi-layer PCBAs create additional costs in the materials and manufacturing process. Generally, moving to a four-layer PCB from a two-layer PCB assembly can make the price to double. Adding more layers to a multi-layer project requires additional cost but the price increase related to putting more layers is not as obvious. For example, the cost to go from 4 layers to 6 layers may represent a 50% increase as opposed to the 100% increase incurred when shifting from a 2-layer to a 4-layer PCB assembly. In essence, adding layers to the production process will incur an added cost. More layers in the printed circuit board assembly are one factor that is calculated to identify the total PCBA cost. Whether it is a single layer, double layer, quadruple layers or multi-layer printed circuit boards, the prices variation is dependent on the number of raw materials. Quantity and Lead Time Quantity and lead time are important in identifying the estimated PCB assembly services cost. You can’t expect that every piece used in the prototyping stage will be as is during the mass production stage. In the prototype or small batch production, there is a required added engineering cost, such as the costs of processing file, stencil, changing SMT line, etc. As a rule of thumb, when smaller quantity and shorter lead time are requested by the client, the cost per unit is usually higher. In terms of quantity, most manufacturers provide a minimum cost for every order. For instance, if you only need 10 pieces for your project, the minimum order cost will require you to pay 20 pieces. As the quantity increases the cost per board is reduced until the minimum manufacturing cost is achieved. Quantity is a critical factor when identifying the PCB assembly cost drivers. Bulk orders are more efficient for the PCB assembly services providers in offering great discounts as they can increase the production level aside from reducing the product cost. Some manufacturers will provide higher quantity discounts but deliver smaller quantities over time. For example, a 500-piece order may be placed with 100 pieces delivered each month until the order has been completely fulfilled. In this case, the manufacturer achieves manufacturing efficiency by producing all 500 pieces at the same time and the customer achieves cash flow efficiency by only paying for the product that has been delivered. In terms of lead time, the old adage, “Time is money,” rings a bell for PCB assembly services providers. The faster a project needs to be produced means it will be more costly – usually between 30% and 200% more. For a PCB assembly manufacturer, there are real costs involved with prioritizing new projects more than the currently existing task. Some of the costs are reflected in the total pricing.

PCB stands for Printed circuit board, which is the chips that supports and electrically connects electronic components or electrical components using conductive tracks, pads and other features etched from one or more sheet layers of copper laminated onto and/or between sheet layers of a non-conductive substrate.PCBA stands for PCB assembly, which is the process of assemble all the electronic component and devices on the bare PCB. Normally it will comes with a bill of materials, which refers to the cost of devices that is being used for the PCB,e.g., resistors, diodes, transistors, etc. There are primarily two types of assembly methods: THD (Thru-Hole Device) Thru-hole technology is accomplished by collaborating manual and automation procedure. It involves three steps as well – components placement, inspection and rectification, and wave soldering. Components placement is manually done by the technician of electronics manufacturer. Components are quickly and precisely placed in their corresponding positions. Inspection and rectification involves checking out if the components are accurately placed and rectified if an error exists. Wave soldering is the process by which the board is passed through a wave of liquid solder with a temperature of 500° Fahrenheit. SMT (Surface-Mount Technology) Surface mount technology is best suited to small sized components and integrated circuits. Surface mount technology features a totally automatic mounting PCB Assembly process. Surface Mount Technology follows three steps in general. The first step is the solder paste printing wherein a solder paste is applied on the board through a solder paste printer. It is very important that the solder paste used is of quality and is applied properly in order to avoid applying it again. The second step is components mounting through components reel in the machine. The last step is the reflow soldering where the board is passed through a 23-foot, 500° Fahrenheit furnace to liquefy the solder paste in order for the SMD components to firmly stick to the board. The steps of PCB assembly process :Solder Paste StencilingPick and PlaceReflow Soldering Inspection and Quality Control： Manual checksAutomatic optical inspectionX-ray inspectionThrough-Hole Component InsertionManual solderingWave solderingFinal Inspection and Functional Test PCB manufacturing, the process of PCB fabrication, e.g.,making the bare board, and PCB assembly are the the two steps of finishing a “functionable” PCB. It is the key step in the turnkey electronic manufacturing services.Most of the PCB is made out in China. China PCB manufacturer tends to congregate in a city called Shenzhen, which is now considered as silicon valley of hardware and it has a significant advantages in labor cost when it comes to PCB assembly compared to PCB manufacturers in USA. 

Flexible printed circuit boards and rigid flexible circuit boards are extremely durable, reliable, and allow you to design circuits that fit the device rather than build the device that fits the circuit board. That is why the design is created upon receipt of specifications That meet the purpose of the final product. Why flexible PCB Encapsulation: unlike a normal PCB, a flexible PCB can be placed almost anywhere, saving space and reducing the weight of a wired solution. In fact, a flexible PCB can save up to 60 percent of the weight and space of a rigid printed circuit board. Flexible printed circuit boards are thin and light and can be folded and positioned to miniaturize electronic devices. Skilled flexible circuit board technicians can use tweezers and fine tip soldering irons to manually weld very small parts under a microscope.Durability and reliability: flexible printed circuit boards reduce the number of interconnections required, which means less soldering and contact bonding. This will leave fewer potential sources of failure, thus improving the reliability of the equipment. In addition the ductility and low quality of the flexible circuit board can significantly reduce the impact of vibration and improve the performance. Polyimide is known for its excellent thermal stability, which enables the equipment to withstand extremely high heat. As a result, flexible circuits are commonly used in military and medical applications. The main cause of circuit board failure may be related to environmental pressure. However, these can be easily avoided when using and storing devices under appropriate conditions. Unlike most rigid circuit boards, flexible circuits can be made of materials more suitable for harsh environments.Cost saving: using flexible printed circuit board, the overall finished product assembly package size and material cost is low. Flexible circuits also reduce wiring errors and test times, thus reducing additional costs.Flexible PCBS can be found in many common household items. Your mobile phone, computer, TV, clock and microwave oven all use FPC. Medical technologies such as scanners and X-ray machines, cars, GPS navigation devices and military technology also use flexible PCBS because they have many advantages over other circuit boards. Flex Design Basics –Static: Not meant to flex.–Flex to Install: Only meant to flex on limited basis. To install or replace and repair.–Dynamic: Depending on flex construction and conditions this could result in 1M flex cycles. Terminology •Back Bared Pads / Back Side Access - This is a flex that is typically single sided in construction but has the copper accessed from both sides.•Conductor aspect ratio - Relationship of conductor width to conductor height. General rule of thumb is conductor width should be greater then 5 times the conductor thickness.•Coverfilm / Coverlay -This is the insulating material, usually in a film format, that is laminated to the flex circuit to define solderable areas. Can be drilled, laser cut or chemically removed to create complex geometries.•Dynamic –A type of flexible circuit that will see repeated flexing, sometimes more than 1 million cycles, such as in a disk drive, mobile phone or laptop computer.•Hold Down Tabs -These are extensions of the copper pad and are used to help anchor the pad during soldering processes both in assembly and rework.•I-Beam Effect -This is the result of stacking your conductors during your design.Subsequent flexing induces stress and compression, causing cracking to occur. •PIC, Photoimagable Coverfilm / Coverlay -This is another means of defining your solderable areas. This material is apply in a clean room environment, exposed with an artwork and then developed. This allows for complex geometries not available from routing or other soft tooling means.•PSA (Pressure Sensitive Adhesive) -An adhesive used to bond stiffeners to specific regions of the flex circuit. I-Beam Effect Always try to avoid “stacking traces” in the same location from layer to layer. Calculating Minimum Bend Radius The general guideline for calculating minimum bend radius is 10X the total thickness of the flexible circuit for double sided (2 layer) applications.The general guideline for calculating minimum bend radius is 6X the total thickness of the flexible circuit for single sided (1 layer) applications.The general guideline for calculating minimum bend radius is 20X -25X the total thickness of the flexible circuit for multi-layer (3+ layers) applications. If you have any questions, please contact us or send us your documents. We will comply with the confidentiality agreement and provide the price.Automatic quotation system

EMPTY WELDING:When two solders are heated differently or one of them has oxidation layer and dirt on the surface, the molten tin will adhere to the solder pad of the solder with higher temperature and clean surface, but not to the solder with low temperature and dirty surface, so that there is still a way between the two solders.THE FALSE WELDING:One of the two soldered bodies has an oxide layer or impurity on its surface, and the molten tin completely covers the soldered body. The two soldered bodies appear to be well connected, but due to the separation of oxide layer and dirt, the conductivity between the two soldered bodies is extremely poor.VIRTUAL WELDING:When two soldered bodies are heated unevenly or the surface of one of them is not very clean, the molten tin is less adhered to the solder plate with a lower temperature and not very clean; Or the welding technique is not correct, so that the molten tin is not evenly and fully attached to the two soldered bodies on the welding plate, the two soldered bodies although the conduction but poor electrical conductivity.COLD WELDING:In the welding process, due to the low welding temperature and short welding time, the tin is not enough time to fully melt, rosin is not volatilized clean and then remove the ferrochrome, so that the connection between the two soldered bodies is not strong and the electrical conductivity is not good, the position of the mouth is dirty, there is a lot of dirt. Causes of defective hollow welding and false welding in pcb manufacturing process: A. device pin oxidation or other impurities leading to poor B. Substrate pad design leading to poorC. Small openings in the PCB stencil and less tin in the weld lead to poor D. Deformation of device pins leads to poorE. Poor quality of solder paste and poor solderability lead to poorF. inappropriate production of temperature curve setting, resulting in poor G. defect of reflux furnace itself, too large T lead to bad Reasons for short circuit caused by poor printing in pcb manufacturing process: A. Insufficient metal content of solder paste, resulting in collapse B. excessive opening of PCB stencil, resulting in excessive tin contentC. PCB stencil quality is not good, tin is not good, change laser cutting templateD. PCB stencil has solder paste on its back to reduce scraper pressure and adopt appropriate VACCUM and SOLVENT PCB Assembly profile for the main purpose of the project A. Preheating zone: solvent volatilization in solder pasteB. Homogenizing zone: flux activation, removal of oxides; evaporation of excess waterC. Re-soldering zone: solder meltingD. Cooling zone: alloy solder joint formation, parts foot and pad joints as a whole In SMT process, the main causes of tin beads are as follows: A.PCB_PAD design is not goodB.PCB stencil opening design is not goodC.Placement depth or pressure is too highD.Profile curve rise slope is too largeE.Paste collapse, paste viscosity is too low If you have any questions, please contact us and our engineers will help you

The general production cost of PCB is 30~60% for direct and indirect raw materials, including substrate, film, copper foil, solder resistance, dry film, drill bit, heavy metal (copper, tin, lead) and chemical consumables. The consumption of these raw materials is directly related to the appropriate size of the layout. Most of the printing factories will do the Layout of the circuit, the Layout will be made to make the assembly of the highest productivity. Therefore, the pre-production designer of PCB factory should communicate with customers closely, so that the size of Layout can be arranged into a working PANEL with the best utilization rate. To calculate the most appropriate layout, consider the following factors.A. The minimum number of substrate cutting and the maximum utilization rate (cutting method and edge grinding shall be taken into account).B. The size of copper foil, film and dry film should be matched with the size of the working PANEL to avoid waste.C. When connecting pieces, the minimum size between pieces and the minimum size of the board edge reserved for tools or alignment system.D. Maximum possible dimensions of each process or valid work-space dimensions.E. Different product structures have different production processes and different typesetting restrictions. For example, the gold-finger plate should have a large spacing and a directional consideration in typesetting. The larger working size can meet the larger productivity, but the raw material cost increases a lot, and the equipment manufacturing capacity also needs to be improved, how to achieve a balance, the design criteria and the engineer's experience is very important.PCBQuick provides high quality quick customization of PCBPCB manufacturing including: LED circuit board, control circuit board, power supply thick copper plate, PCB design and PCB copy services.

This should be examined in three parts:1. The LED lamp bead or resistance may be damaged.2. It may be component virtual welding or de-welding.3, may be what you said, the led pcb board is not good, can be used to detect the multimeter between the components of the line, whether disconnected.In order to have a good heat dissipation effect, LED pcb board is usually aluminum substrate, the first layer is the surface line, the second layer is the insulation layer, the third layer is aluminum plate. Aluminum LED PCB QA Film Inspection

1. It is strictly prohibited to use the grounded test equipment to touch the live TV, audio, video and other equipment on the base plate to detect the PCB board without isolating transformerIt is forbidden to directly test TV, audio, video and other equipment without power isolating transformer with equipment with grounded enclosure. Although generally the recorder has power transformer, when exposed to a special especially or larger output power of the nature of the power supply do not know much about TV or stereo equipment, first make clear the machine chassis is charged, otherwise extremely easy and floor live TV, audio and other equipment power supply circuit, spread to the integrated circuit, further breakdowns. 2. Pay attention to the insulation performance of electric soldering iron when testing PCB boardIt is not allowed to use soldering iron for soldering. To ensure that the soldering iron is not electrified, it is best to ground the shell of the soldering iron. You should be more careful with MOS circuit.3. Understand the working principle of integrated circuits and related circuits before testing the PCB boardBefore checking and repairing an integrated circuit, it is necessary to be familiar with the function of the integrated circuit, internal circuit, main electrical parameters, functions of each pin, normal voltage of the pin, waveform and working principle of the circuit composed of peripheral components. If the above conditions are met, then the analysis and inspection will be much easier.4. Test PCB board should not cause short circuit between pinsWhen the voltage is measured or the waveform is tested with the oscilloscope probe, the watch pen or probe should not cause short circuit between the integrated circuit pins due to sliding, and it is best to measure on the peripheral printed circuit directly connected with the pin. Any momentary short circuit can easily damage an integrated circuit, especially when testing flat CMOS integrated circuits.5, test PCB test instrument internal resistance to be largeDc voltage measurement IC pin, should choose header Ω resistance is greater than 20 k/V multimeter, or for some pin voltage will have larger error of measurement.6. Pay attention to heat dissipation of power integrated circuit when detecting PCB boardPower integrated circuit should be good heat dissipation, not allowed to work without a radiator in the state of high power.7. Test PCB lead shall be reasonableIf it is necessary to add peripheral components to replace the damaged part inside the integrated circuit, small components should be selected, and the wiring should be reasonable to avoid unnecessary parasitic coupling, especially to deal with the grounding terminal between the audio power amplifier integrated circuit and the preamplifier circuit.8. PCB inspection shall ensure the welding qualityWelding is indeed firm, the accumulation of solder, gas hole is easy to cause virtual welding. The welding time is generally not more than 3 seconds, the power of the soldering iron should be about 25W. The already welded integrated circuit should be carefully examined, it is best to use the ohmmeter to measure whether there is a short circuit between the pins, and confirm that there is no solder adhesion before connecting the power supply.9, test PCB board do not easily determine the damage of the integrated circuitDo not easily judge that the integrated circuit is damaged. Since most integrated circuits are directly coupled, once a circuit is abnormal, it may lead to multiple voltage changes, which may not be caused by the damage of the integrated circuit. In addition, under some circumstances, when the measured voltage of each pin is consistent with or close to the normal value, it may not indicate that the integrated circuit is good. Because some soft faults will not cause dc voltage changes.

What does LED PCB design need to provide? PCBQuick provides single-PCB, double-sided PCB, multilayer PCB, PCB replication, PCB design, PCB schematic design, PCB layout, BOM production, PCB prototype production, finished product batch processing, technical support, PCB production and other high-frequency circuits Board quality assurance service.For the PCB design of a customer who has a schematic and does not have a schematic, a program client is required. The specific business process is as follows. The customer has a schematic and needs to provide:1. Schematic file format: PowerPCB, Protel99 / se, PADS20002. BOM list3. PCB size4. Component specifications5. Fixed position holeNo schematic customer, need to provide:1. Design the PCB size to complete the acceptable blank height of the shell (so that the engineer can select the height of the component)2. Functional requirements (functions required to explain or detail the product)3 customer certification requirements, warranty requirements4. If a brand finished product, provide the specific model.

Signal Layers Signal Layer includes Top Layer, Bottom Layer, Mid Layer 1... 30. Mid layer refers to the intermediate plate layer used for wiring, in which the conductor is arranged.Top Layer is also called the component Layer, which is mainly used for placing components. For the double sided pcb and multilayer pcb, it can be used to arrange wires or cover copper.Bottom Layer, also known as the welding layer, is mainly used for wiring and welding. For the double sided and multilayer pcb, it can be used to place components.Mid-Layers can be up to 30 Layers, and are used to lay signal lines in multilayer pcb, excluding power and ground lines. Internal Plane This type of layer is only used for multi-layer pcb. These layers are generally connected to ground and power supply, and also have electrical connection. However, this layer is generally not wired and is composed of the whole copper film. The number of PCB plates generally refers to the sum of the signal layer and the Internal Plane. Silkscreen Overlay A PCB board can have up to 2 silk-screen layers. Includes Top overlay and Bottom overlay. It is usually printed on the resistance welding layer, such as component name, component symbol, component pin and copyright, etc., to facilitate future circuit welding and error checking.If all marks in the Top overlay are already included, the Bottom overlay can be closed. Solder Mask Refers to the part of the PCB board to be covered with green oil; Because it is negative output, the actual effect of the soldermask part is not green oil, but tinned ! Resistance welding layer means to open a window on the whole resistance welding green oil, in order to allow welding;By default, green oil is applied to all areas without a resistance layer