Single-panel: opening - drilling - graphic transfer (including screen printing wet film, alignment exposure, development) - etching - printing solder resist (green oil) - spraying tin (leaded and lead-free two kinds) - printing text - molding (CNC milling machine or punching machine)
Double-sided board: opening - drilling - copper sinking - graphic transfer (including screen printing wet film, alignment exposure, development) - graphic plating (first copper-plated and then tin-plated) - retiring - etching - printing solder resist (green oil) - spraying tin (leaded and lead-free two kinds) - printing text - molding (CNC milling machine or punching machine) Graphic plating (first copper plating and then tin plating) - desmear - etching - printing solder resist (green oil) - spraying tin (leaded and lead-free two kinds) - printing text - molding (with CNC milling machine or punch press)
Four-layer board: opening - inner layer graphic transfer - inner layer of etching - laminating - drilling - copper immersion - outer layer graphic transfer - graphic plating - desmear etching - printing solder resist (green oil) - spraying tin (leaded and lead-free two kinds) - printing text - molding (with CNC milling machine or punch press) Printing text - Molding (with CNC milling machine or punch)
Basically that's the general process. From what profile? The file the customer sends over or what? If there is a press-fit, it is a multi-layer board, press once is four layers, in short, every press is two more layers.
Process inspection IPQC process is what kind ofIPQC: refers to the quality control of the entire production process, IPQC's basic process is first of all, the production instructions to the production site to organize and installations in addition to the error to the first pieces of the inspection to the IPQC's formal inspection to the inspection process to the quality of abnormalities occurring in the treatment of quality anomalies in the treatment of tracking. Flow charts please pay attention to jibu three skin of Baidu library, which has a large number of business management files and information.
Process Inspection (IPQC) workflow and work content
1, IPQC personnel should be in the end of each day before the end of the day to understand the next day's manufacturing sector responsible for the status of the production plan, in order to prepare the inspection of the relevant information in advance.
2, the manufacturing department to produce a product before the IPQC personnel should be aware of the query in advance of the relevant information:
(A) Manufacturing order form;
(B) technical drawings for inspection;
(C) product material schedule;
(D) the scope of the inspection and inspection standards;
(E) the process, operation (E) process flow, operating instructions (operating standards);
(F) quality exception records;
(G) other related files;
3, the manufacturing department to start production, IPQC personnel should assist the manufacturing department to assist the main assistance as follows:
(A) process check;
(B) the relevant materials, tooling and fixtures to check;
( (C) the use of measuring instruments point inspection;
(D) the operator quality standards guidance;
(E) the first product inspection records;
4, IPQC according to the drawings, limit samples of the results of the inspection is qualified before the normal production, and fill out the first inspection report and stay in the first inspection of the first inspection of the qualified product (the first production of the first qualified product) as the batch of the limit of production. Sample.
5, after the normal production of the manufacturing sector, IPQC personnel in accordance with the specified time for inspection, inspection time is generally provided as follows:
1 inspection A: 8:00 B: 8:30 C: 9:00 D: 9:30 or according to a certain batch of inspection.
6, IPQC inspection found defective products should be timely analysis of the causes and operators of irregularities in the action sequence and timely correction.
7, IPQC on the inspection station of the bad need to cooperate with the manufacturing sector management or technical personnel to deal with, analyze the causes and make abnormal problems of preventive measures and preventive measures.
8, major quality abnormalities, IPQC failed to deal with, should be issued by the production director of the "process abnormality notification form" by the production supervisor audit, notify the relevant departments to deal with the relevant departments.
9, major quality anomalies can not be dealt with in a timely manner, IPQC has the responsibility to require the manufacturing department to stop or stop the line processing, to stop the continued manufacture of bad.
10, IPQC should be timely inspection of the situation recorded in the "process inspection record sheet" daily to the department head, manager, in order to facilitate timely grasp of the production quality situation.
PCB manufacturing process - Mechanical Process Department
Manufacturing process
PCB manufacturing process by the glass epoxy resin (Glass Epoxy) or similar materials made of "substrate" to start.
Imaging (molding/lead generation)
The first step in the fabrication process is to create the wiring for the interconnections between the parts. We use a subtractive transfer to represent the working negative on a metal conductor. This technique involves laying a thin layer of copper foil over the entire surface and eliminating the excess. Additive Pattern transfer is another lesser-used method, which involves applying copper wire only where it is needed, but we won't go into that here.
If you're making a double-sided board, the PCB is covered with copper foil on both sides of the substrate, and if you're making a multilayer board, the next step is to glue the boards together.
The next flowchart shows how the wires are soldered to the substrate.
Imaging (molding/wire fabrication), continued
Positive photoresist is made from a photoconductor that dissolves when illuminated (negative photoresist breaks down if it is not illuminated). There are a number of ways to treat photoresist on copper surfaces, but the most common way is to heat it up and roll it over the surface containing the photoresist (called dry film photoresist). It can also be sprayed on in a liquid form, but the dry-film type offers higher resolution and allows for finer wires to be made.
The photoresist is just a template for the PCB layer in manufacturing. Before the resist on the PCB is exposed to UV light, a mask covering it prevents some areas of the resist from being exposed (assuming a positive resist is used). These areas covered by the photoresist will become the wiring.
After the resist is developed, the rest of the bare copper is etched. The etching process can be done by immersing the board in an etching solvent or by spraying the solvent on the board. Generally used as etching solvents are Ferric Chloride (Ferric Chloride), Alkaline Ammonia (Alkaline Ammonia), Sulfuric Acid + Hydrogen Peroxide (Sulfuric Acid + Hydrogen Peroxide), and Cupric Chloride (Cupric Chloride). After etching, the remaining photoresist is removed. This is called the Stripping program.
You can see how the copper wires are routed in the image below.
This procedure can be done on both sides of the wire at the same time.
Drilling and plating
If you are making a multilayer PCB with buried or blind vias, each layer must be drilled and plated before it is glued together. Without this step, there is no way to connect the wires to each other.
After the holes are drilled by the machine according to the drilling requirements, the inside of the hole must be plated (Plated-Through-Hole technology, PTH). Plated-Through-Hole technology (PTH) allows the internal layers of wiring to be connected to each other by treating the inside of the hole with metal. Before plating is started, it is necessary to remove debris from the hole. This is because the resin epoxy produces some chemical changes when heated, and it will cover the internal PCB layer, so it must be removed first. Both the removal and plating actions will be done in the chemical process.
Multilayer PCB Pressing
The individual layers must be pressed together to create a multilayer board. Lamination involves adding insulation between the layers and gluing them to each other. If there are vias through several layers, the process must be repeated for each layer. The wiring on the outer faces of the multilayer board is usually handled after the multilayer board is pressed together.
Handling Soldermask, Stencil Surfaces, and Gold Finger Plating
Next, soldermask is applied to the outermost layer of the wiring so that the wiring does not touch the outside of the plating. The screen print is then printed on top of it to indicate the location of the parts. It should not cover any of the wires or the gold finger, as this may reduce solderability or the stability of the current connection. The gold fingers are usually gold plated to ensure a high quality connection when plugging into an expansion slot.
Testing
Testing a PCB for shorts or breaks can be done optically or electronically. Optical testing uses scanning to find defects in each layer, while electronic testing typically uses a Flying-Probe to inspect all wires. Electronic testing is more accurate at finding shorts or breaks, but optical testing makes it easier to detect problems with incorrect gaps between conductors.
Mounting and Soldering
The final step is to mount and solder the parts. Both THT and SMT parts are mounted on the PCB using mechanical devices.
THT parts are usually soldered using a method called Wave Soldering. This allows all parts to be soldered to the PCB in one pass, first cutting the pins close to the board and bending them slightly to allow the parts to be held in place. Next, the PCB is moved to a wave of flux, where the underside is exposed to the flux, which removes the oxides from the metal on the underside. After heating the PCB, this time it is moved to the melted solder, and after contact with the bottom, the soldering is complete.
The automatic soldering of SMT parts is called Over Reflow Soldering. Inside the paste containing flux and solder solder in the parts installed on the PCB after the first treatment, after the PCB is heated and then processed again. After the PCB cools down, the soldering is complete and the PCB is ready for final testing.
Ways to save on manufacturing costs
In order to keep the cost of the PCB as low as possible, there are a number of factors that have to be taken into account:
The size of the board is naturally a priority. The smaller the board, the lower the cost. Some of the PCB sizes have become standardized, so if you follow them, the cost will come down naturally.
Using SMT will save you money compared to THT because the parts on the PCB are denser (and smaller).
On the other hand, if the board is very dense, the wiring has to be finer, and the devices used have to be relatively high level. At the same time, the materials used have to be of a higher order, and more care has to be taken in the design of the wires to avoid problems such as power dissipation that can affect the circuitry. The cost of these issues can be more than offset by reducing the size of the PCB.
The more layers you have, the more expensive it is, but PCBs with fewer layers usually have a larger size.
Drilling takes time, so the fewer vias the better.
Buried vias are more expensive than vias through all layers. This is because buried holes have to be drilled before they are joined.
The size of the holes on a board is determined by the diameter of the part's pins. If there are parts with different types of pins on the board, then because the machine can't use the same drill to drill all the holes, it's more time consuming and represents a higher manufacturing cost.
Electronic testing using flying probe methods is usually more expensive than optical methods. Generally speaking, optical testing is sufficient to ensure that there are no errors on the PCB.
In summary, manufacturers are getting more sophisticated with their devices. Understanding how PCBs are made is useful because when we are comparing motherboards, boards of the same performance can have different costs and varying stability, and this allows us to compare the capabilities of each vendor.
A good engineer can tell just by looking at a motherboard design how good the design is. You may not think so, but the next time you get a motherboard or graphics card, you might want to take a look at the beauty of the PCB design!
What is the process of making a negative PCB?Printed circuit boards (PCBs) are found in almost every kind of electronic device. If there are electronic parts in a device, they are mounted on PCBs of various sizes. In addition to fixing a variety of small parts, PCB's main function is to provide the top of the various parts of the mutual electrical connection. With the electronic device is more and more complex, the need for more and more parts, PCB on the head of the line and parts are also more and more dense. The standard PCB looks like this. Bare board (no parts on the top) is also often called "Printed Wiring Board Printed Wiring Board (PWB)".
The substrate of the board itself is made of insulating, non-bending material. On the surface of the small lines can be seen in the material is copper foil, the original copper foil is covered in the entire board, and in the manufacturing process, some of the middle part is etched away, leaving the part of the net into a small line. These lines are called conductors (conductor pattern) or wiring, and are used to provide circuitry connectivity to parts on the PCB.
In order to secure the parts to the PCB, we solder their pins directly to the wiring. On the most basic PCBs (single panel), the parts are concentrated on one side and the wires are concentrated on the other. In this case we need to punch holes in the board so that the pins can go through the board to the other side, so the pins of the parts are soldered to the other side. Because of this, the front and back sides of the PCB are called the Component Side and Solder Side, respectively.
If there are certain parts on the PCB that need to be taken off or put back on after the production is complete, then the part will be installed using the socket (Socket). Since the socket is soldered directly to the board, the part can be disassembled and reassembled at will. Below you see a ZIF (Zero Insertion Force) socket, which allows the part (in this case the CPU) to be easily *** socketed or removed. There is a retaining bar next to the socket that holds the part in place after you **** it.
To connect two PCBs to each other, we usually use an edge connector, commonly known as a "gold finger". The edge connector contains a number of *** copper pads that are actually part of the PCB wiring. Usually, when connecting wires, we put the edge connector on one piece of PCB *** on the appropriate slot on the other piece of PCB (usually called expansion slot). In computers, such as graphics cards, sound cards, or other similar adapters, the connectivity to the motherboard is through the gold finger.
The green or brown color of the PCB is the color of the solder mask. This is an insulating shield that protects the copper wires and prevents parts from being soldered in the wrong place. On top of the solder mask, a silk screen is printed. Usually, text and symbols (mostly white) are printed on this screen to indicate the location of the parts on the board. The silk screen is also called a legend.
What is the pcb production process?Go to the PCB factory website. It's a very detailed process.
For example:
1) Single panel process
Unwelded grinding → drilling → outer graphics → (full-board gold plating) → etching → inspection → silk screen soldermasking → (hot air leveling) → silk screen characters → shape processing → test → inspection
2) double-sided tin plate process
Unwelded grinding → drilling → copper thickening → outer graphics → tin plating, etching and desoldering. Tin-plating, etching and retinning → secondary drilling → inspection → silkscreen soldering → gold-plated plug → hot air leveling → silkscreen characters → shape processing → test → inspection
3) Double-sided nickel and gold-plated process
Unwelded milling → drilling → thickening of the immersed copper → outer layer of the graphic → nickel-plating, gold film etching → secondary drilling → inspection → screen soldering → silkscreen character → shape processing → test → test
4) Multi-layer board spray tin process
Unwelded milling → drilling → copper thickening → outer layer of the graphic
4) Multilayer tin spray board process
Unwelded grinding → drilling positioning holes → inner layer graphics → inner layer etching → inspection → blackening → lamination → drilling → immersion copper thickening → outer layer graphics → gold-plated, de-film etching → secondary drilling → inspection → silk screen solder resist → silk screen characters → shape processing → test → inspection
6) multilayer immersion nickel-gold plate process
Unwelded grinding → drilling positioning holes → inner layer graphics → inner layer etching Etching → inspection → blackening → lamination → drilling → copper thickening → outer graphics → tin plating, etching and retinning → secondary drilling → inspection → silkscreen solder resist → chemical immersion nickel gold → silkscreen characters → shape processing → test → inspection
pcb board production process is?
Take a simple double-sided OSP board as an example:
Uncrating → drilling → chemical immersion copper → full-board plating → outer line → graphic plating → outer etching → solder resist → silkscreen character → molding → finished product cleaning → test → OSP → FQC → FQA → packaging and warehousing
Remarks: There are many kinds of surface treatment, and the location of its production process will be different for different surface treatments.
What is the wet process in PCB?Wet process has: chemical precipitation of copper, etching, electroplating copper, nickel gold, tin, chemical precipitation of silver, chemical precipitation of nickel gold, OSP surface antioxidant film and so on. Mainly refers to some of the processes that need to be completed in a chemical solution. It does not refer to a particular process.
If the process is divided into electroplating, surface treatment, chemical plating (chemical precipitation of copper, gold, silver, tin, nickel, etc.)
What is the fpc processFPC generally refers to flexible circuit boards
Flexible circuit boards are made of polyimide or polyester film as the substrate of a high degree of reliability, excellent flexible printed circuit boards. It is characterized by high wiring density, light weight, thin thickness, and good bendability.
In the production process, in order to prevent too many open and short circuit caused by low yield or reduce drilling, calendering, cutting and other coarse process problems caused by the FPC board scrap, replenishment problems, and assess how to choose the material to achieve the best results for customers to use the flexible circuit board. Pre-production pre-processing is particularly important.
Pre-production pre-processing, need to deal with three aspects, these three aspects are completed by engineers. First of all, the FPC board engineering assessment, mainly to assess whether the customer's FPC board can be produced, the company's production capacity to meet the customer's board requirements as well as the unit cost; if the engineering assessment is passed, the next step is the need to immediately prepare materials to meet the supply of raw materials for various production processes, and finally, engineers on: the customer's CAD structural drawings, gerber line information, such as the project file to deal with, in order to Finally, the engineer to: customer CAD structure drawings, gerber line data and other engineering files to deal with the production of production equipment suitable for the production environment and production specifications, and then production drawings and MI (engineering process card) and other information decentralized to the Ministry of Production and cultural control, procurement and other departments, into the regular production process.
What is the PCB text manufacturing process in CAM genesis2000?Positive copy of the anti-solder layer to a new layer and increase, and then use this new layer against the character layer, the contact to the explosion-proof PAD character removal, the upper PAD character box enlargement, and then increase the anti-solder layer after the character layer hollow out the layer, and finally add the company's UL mark.
What is the process of PCB gold fingerHere
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