Double panel: cutting-drilling-copper plating-pattern transfer (including screen printing wet film, counterpoint exposure and development)-pattern electroplating (copper plating first and then tin plating)-film stripping-etching-printing solder resist (green oil)-tin spraying (with lead and lead)-printing characters-forming (using CNC milling machine or punch).
Four-layer board: cutting-inner layer pattern transfer-inner layer etching-lamination-drilling-copper plating-outer layer pattern transfer-pattern electroplating-stripping etching-anti-corrosion printing (green oil)-tin spraying (lead-free)-printing-forming (using CNC milling machine or punch)
Basically, the general process is like this. From what information? Documents sent by customers or something? If there is pressure, it is a multi-layer board, four layers at a time. In short, every time you press it, there are two more layers.
What is the IPQC process of process inspection? It refers to the quality control of the whole production process. The basic flow of IPQC is the arrangement of production instructions to the production site, the debugging of equipment to the inspection of the first article, the formal inspection of IPQC, the handling of quality anomalies in the inspection process and the tracking of quality anomalies. For the flow chart, please pay attention to the three batches of Baidu Library in Ji Bu, which contains a large number of enterprise management files.
Process Inspection (IPQC) Workflow and Work Contents
1.IPQC personnel should know the production plan of the competent manufacturing department for the next day before leaving work every day, so as to prepare relevant inspection materials in advance.
2. Before the manufacturing department produces a certain product, IPQC personnel should know the relevant information in advance:
Manufacturing order;
(b) Technical drawings for inspection;
(c) List of materials used in the product;
(d) Inspection scope and standards;
(e) Process flow and operation instruction (operation standard);
Records of abnormal quality;
(g) Other relevant files;
3. When the manufacturing department starts production, IPQC personnel should assist the manufacturing department, mainly as follows:
Process flow inspection;
(b) Check relevant materials, tools and fixtures;
(c) Spot check with measuring instruments;
(d) Guidelines on quality standards for operators;
(e) Inspection records of the first inspected product;
4.IPQC can start normal production only after the inspection results of drawings and limited samples are qualified, and fill in the first product inspection report, and keep the first qualified product (the first qualified product in production judgment) as the production limited model of this batch.
5. After the production of the manufacturing department is normal, IPQC personnel will conduct patrol inspection according to the specified time. The patrol inspection time is generally specified as follows:
1 round inspection A: 8: 00 B: 8: 30 C: 9: 00 D: 9: 30 or according to a batch inspection.
6. When defective products are found in 6.IPQC inspection, the reasons shall be analyzed in time, and the irregular action sequence of the operators shall be corrected in time.
7.IPQC shall promptly cooperate with the management or technical personnel of the manufacturing department to deal with the defects of the inspection station, analyze the reasons and formulate preventive measures and preventive measures for abnormal problems.
8. If 8.IPQC can't handle major quality anomalies, it shall issue a Notice of Process Anomalies, which shall be reviewed by the production supervisor and notified to relevant departments for handling.
9. If major quality anomalies are not handled in time, IPQC has the responsibility to ask the manufacturing department to stop or stop handling, so as to prevent further manufacturing defects.
10.IPQC shall record the inspection in the process inspection record form in time, and submit it to department heads and managers every day, so as to grasp the production quality status in time.
PCB manufacturing process-manufacturing process of mechanical processing department
The manufacturing process of PCB begins with a "substrate" made of glass epoxy or similar materials.
Image (forming/thread making)
The first step in manufacturing is to establish the connection between parts. We use negative transfer to show the working film on the metal conductor. This technology is to spread a thin layer of copper foil on the whole surface to eliminate the redundant parts. Additional pattern transfer is another rarely used method. It is a method of laying copper wire only where necessary, so I won't talk about it here.
If it is a double panel, both sides of the PCB substrate should be covered with copper foil. If multi-layer boards are made, these boards will be bonded together in the next step.
The next flow chart introduces how the wires are soldered on the substrate.
Image (forming/thread making), continued
Positive photoresist is made of photosensitizer and will dissolve under light (negative photoresist is not only decomposed). There are many methods to treat photoresist on copper surface, but the most common method is to roll it on the surface containing photoresist after heating (called dry film photoresist). It can also be sprayed on it in liquid form, but the dry film provides higher resolution and can also make thinner wires.
The hood is only a template for PCB layer in manufacturing. Before the photoresist on PCB is exposed to ultraviolet light, the photomask covering it can prevent the photoresist in some areas from being exposed (assuming that positive photoresist is used). These areas covered with photoresist will become wiring.
Other bare copper parts to be etched after photoresist development. During the etching process, the plate can be immersed in the etching solvent or sprayed with the solvent. Commonly used as etching solvents are ferric chloride, basic ammonia, sulfuric acid plus hydrogen peroxide and copper chloride. After etching, the remaining photoresist is removed. This is the so-called stripping procedure.
You can see how the copper wire is wired from the picture below.
This step can be used to route wires on both sides at the same time.
Drilling and electroplating
If a multi-layer PCB is made and it contains buried holes or blind holes, each layer of PCB must be drilled and electroplated before bonding. If you don't go through this step, then there is no way to contact each other.
After the machine drills the hole according to the drilling requirements, the inner side of the hole wall must be electroplated (PTH). After metal treatment in the hole wall, the inner circuits can be connected with each other. Impurities in the holes must be removed before electroplating. This is because the epoxy resin will produce some chemical changes after heating, which will cover the internal PCB layer, so it should be removed first. Cleaning and electroplating actions will be completed in the chemical process.
Multilayer printed circuit board pressing
Each layer must be pressed into a multilayer board. The pressing action includes adding insulating layers between layers and sticking them together. If there are several layers of through holes, each layer must be processed repeatedly. The wiring on the outer two sides of the multilayer board is usually processed after the multilayer board is pressed.
Treatment of solder resist, screen printing surface and gold finger electroplating
Next, cover the outermost wiring with solder resist paint, so that the wiring will not contact the electroplated part. Screen printing is printed on it, indicating the position of each part. It cannot cover any wiring or gold fingers, otherwise it may reduce solderability or the stability of current connection. Gold fingers are generally gold-plated to ensure high-quality current connection when inserted into the expansion slot.
test
Test PCB for short circuit or open circuit, which can be tested by optical or electronic means. Optical scanning is used to find out the defects of each layer, while electronic testing usually uses flying needles to check all connections. Electronic testing is more accurate in finding short circuits or open circuits, but optical testing can more easily detect the problem of incorrect gaps between conductors.
Parts installation and welding
The last step is to install and weld the parts. THT and SMT parts are installed and placed on PCB by mechanical devices.
THT parts are usually welded by a method called wave soldering. This allows all devices to be soldered to the PCB at the same time. First, cut the pins near the circuit board and bend them slightly so that the parts can be fixed. Then, the PCB is moved into the water wave of the cosolvent, so that the bottom touches the cosolvent, so that the oxide on the bottom metal can be removed. After heating the PCB, it is moved to the molten solder this time, and the welding is completed after touching the bottom.
Automatic soldering of SMT parts is called reflow soldering. Solder paste containing cosolvent and solder is treated once after the parts are mounted on PCB, and then treated again after the PCB is heated. After the PCB is cooled, the welding is completed, and then the PCB is ready for final testing.
Method for saving manufacturing cost
In order to keep the cost of PCB as low as possible, there are many factors that must be considered:
The size of the chessboard is naturally important. The smaller the circuit board, the lower the cost. Part of the size of PCB has become a standard. As long as it is done according to the size, the cost will naturally be reduced. There is some information about standard sizes on the CustomPCB website.
Using SMT will save money than THT, because the parts on PCB will be denser (and smaller).
On the other hand, if the parts on the board are dense, the wiring must be thinner and the devices used are relatively higher. At the same time, the materials used are also higher, so we must pay more attention to the design of wires to avoid problems that will affect the circuit, such as power consumption. These problems bring more cost than reducing PCB size.
The more layers, the higher the cost, but a PCB with fewer layers usually leads to an increase in size.
Drilling takes time, so as few pilot holes as possible.
Buried holes are more expensive than guide holes that run through all layers. Because it is necessary to drill buried holes before connection.
The size of the hole on the board is determined according to the diameter of the device pin. If there are parts with different types of pins on the circuit board, it is relatively time-consuming because the machine can't drill all the holes with the same drill, which also means that the manufacturing cost is relatively increased.
Electronic testing using flying needle detection is usually more expensive than optical testing. Generally speaking, optical testing is enough to ensure that there are no errors on the PCB.
In a word, manufacturers' efforts in installation are becoming more and more complicated. It is very useful to know the manufacturing process of PCB, because when we compare motherboards, the cost and stability of boards with the same performance may be different, which also allows us to compare the capabilities of various manufacturers.
A good engineer can know the quality of the design just by looking at the motherboard design. You may feel that you are not so strong, but the next time you get a motherboard or graphics card, you might as well appreciate the beauty of PCB design first!
What is the production process of PCB negatives? Printed circuit board (PCB) will appear in almost every kind of electronic equipment. If there are electronic parts in a device, they are all embedded in PCB of different sizes. In addition to fixing various small parts, PCB is mainly used to provide electrical connection between the above parts. With the increasing complexity of electronic devices, more and more components are needed, and the lines and components on PCB are more and more dense. A standard PCB looks like this. A bare board (with no parts on it) is also often called a "printed circuit board (PWB)".
The substrate of the board itself is made of insulating and heat-insulating materials that are not easy to bend. The fine wiring material visible on the surface is copper foil. Originally, the whole board was covered with copper foil, but a part of it was etched away in the manufacturing process, and the rest became fine wiring in a mesh. These lines, called conductor patterns or wiring, are used to provide circuit connections for components on the PCB.
In order to fix the parts on the PCB, we weld their pins directly on the wiring. On the most basic PCB (single board), the parts are concentrated on one side and the wires are concentrated on the other side. In this way, we need to make holes in the board so that the pins can pass through the board to the other side, so the pins of the parts are welded to the other side. Because of this, the front and back of PCB are called component surface and soldering surface respectively.
If there are some parts on the PCB that need to be removed or put back after production, sockets will be used when installing the parts. Because the socket is directly welded on the board, the parts can be disassembled at will. What you see below is the ZIF (Zero Insertion Force) socket, which makes it easy for parts (in this case, CPU) to be plugged in or deleted. The fixing rod next to the socket can be fixed behind your parts.
If we want to connect two PCB boards to each other, we usually use the edge connector commonly known as "Golden Finger". Gold finger contains many copper pads, which are actually part of PCB wiring. Usually, when connecting, we put the gold finger on one PCB into the corresponding slot (commonly known as expansion slot) on another PCB. In computers, such as graphics cards, sound cards or other similar interface cards, they are all connected to the motherboard through gold fingers.
Green or brown on PCB is the color of solder mask. This layer is an insulating protective layer, which can protect the copper wire and prevent the parts from being welded to incorrect places. In addition, a screen will be printed on the solder mask. Usually words and symbols (mostly white) are printed on it, indicating the position of each part on the chessboard. Screen printing surface is also called legend.
What is the production process of pcb? Go to the PCB factory website. Very detailed process.
For example:
1) single board process
Cutting and edging → drilling → external graphics → (all-plate gold plating) → etching → inspection → screen printing and welding resistance → (hot air leveling) → screen printing characters → shape processing → testing → inspection.
2) Process flow of double-panel tin spraying plate
Cutting and edging → drilling → sinking copper and thickening → external graphics → tin plating and etching → secondary drilling → inspection → screen printing and solder resist → gold-plated plug → hot air leveling → screen printing text → shape processing → testing → inspection.
3) process flow of nickel and gold plating on double panels
Cutting and edging → drilling → copper sinking and thickening → outer layer pattern → nickel plating, gold stripping and etching → secondary drilling → inspection → screen printing and welding resistance → screen printing characters → shape processing → testing → inspection.
4) Process flow of multi-layer tinplate
Trimming → drilling locating holes → inner layer pattern → inner layer etching → inspection → blackening → lamination → drilling → copper sinking and thickening → outer layer pattern → tin plating, etching and tin stripping → secondary drilling → inspection → screen printing solder resist → gold plated plug → hot air leveling → screen printing characters → shape processing → testing → inspection.
5) process flow of nickel and gold plating on multilayer board
Trimming → drilling locating holes → internal pattern → internal etching → inspection → blackening → lamination → drilling → copper deposition and thickening → external pattern → gold plating and film removal etching → secondary drilling → inspection → screen printing and welding resistance → screen printing characters → shape processing → testing → inspection.
6) process flow of nickel and gold plating on multilayer board
Trimming → drilling locating holes → internal pattern → internal etching → inspection → blackening → lamination → drilling → sinking copper and thickening → external pattern → tin plating and etching for tin removal → secondary drilling → inspection → screen printing for solder resist → electroless nickel plating → screen printing for characters → shape processing → testing → inspection.
What is the production process of pcb board? Take a simple double-sided OSP board as an example:
Cutting → Drilling → Chemical Copper Deposition → Full Plate Electroplating → External Circuit → Graphic Electroplating → External Etching → Soldering Prevention → Screen Printing Characters → Forming → Finished Product Cleaning → Testing → OSP→ FQC→ FQA→ Packaging and Storage.
Remarks: There are many kinds of surface treatments, and different surface treatments have different production process positions.
What is the wet process in PCB? Wet process includes: chemical deposition of copper, etching, electroplating of copper, nickel gold, tin, chemical deposition of silver, chemical deposition of nickel gold, OSP surface oxidation-resistant film, etc. . Mainly refers to some processes that need to be completed in chemical solutions. Not just a process.
According to the process, it can be divided into electroplating, surface treatment and electroless plating (electroless copper plating, gold plating, silver plating, tin plating, nickel plating, etc. )
What is fpc technology? FPC refers to flexible printed circuit board.
Flexible printed circuit board is a kind of high reliability and excellent flexible printed circuit board based on polyimide or polyester film. It has the characteristics of high wiring density, light weight, thin thickness and good flexibility.
In the production process, in order to prevent the yield from being too low due to too many open circuits and short circuits, or to reduce the problems of scrap and material replenishment caused by rough process problems such as drilling, calendering and cutting of FPC boards, how to select materials to achieve the best effect for customers is evaluated. Prenatal pretreatment is particularly important.
Prenatal pretreatment has to deal with three aspects, all of which are completed by engineers. The first is the evaluation of FPC board project, which mainly evaluates whether the customer's FPC board can be produced, whether the company's production capacity can meet the customer's board-making requirements and unit cost; If the project evaluation passes, materials need to be prepared immediately to meet the supply of raw materials in all production links. Finally, the engineer processes the customer's engineering documents such as CAD structure diagram and gerber line data to adapt to the production environment and production specifications of the production device, and then entrusts the production drawings and MI (engineering process card) to the production department, document control department, purchasing department and other departments to enter the regular production process.
What is the production process of PCB characters in CAM genesis2000? Copy the positive film of solder mask to a new layer and enlarge it, then use this new layer to control the character layer, remove the characters touching the explosion-proof pad, enlarge the character frame on the pad, then remove the character layer with the enlarged solder mask, and finally add the company's UL logo.
What is the process of PCB gold plating here?
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