PCBs constitute the basis of all large electronics. These miracle discoveries appear in almost all computer electronics, including simpler devices such as digital clocks, calculators, etc. For the non-initiated, a PCB routes electronic signals that satisfy the system’s electrical and mechanical circuit requirements. In short, PCBs say where to go to power and make your electronics come alive.
“This Article is brought to you by Victory PCB, one most experienced customer service providers. Understanding their customers’ success measures performance, Victory PCB concentrates on the attention and attention to details required for every PCB production phase. Also, have vacuum packing, weighting, and shipping to ensure PCB order is secure and damage-free. They have so far printed platforms for companies of all sizes from more than 80 countries, and in the coming years, their goal is to supply manufactured PCBs to every corner of the world.”
PCBs direct current through a network of copper paths across their surface. The complex copper system decides the specific position of each PCB circuit board component.
Before designing PCBs, circuit designers can visit a PC board store and meet with manufacturers face to face with their production needs for their PCBs. It helps prevent designers from transmitting needless errors during the design phase. However, as more businesses outsource their PCBs to manufacturers abroad, this becomes unpractical. This is why we present this article to provide a proper understanding of PCB board manufacturing process steps. It hopefully gives PCB industry new circuit designers a clear vision of how printed circuit boards are produced and prevents needless mistakes from being made.
PCB Manufacturing Steps
Step 1: Design and Output
Circuit boards should be strictly consistent with a PCB design software layout developed by the designer. The popular program for PCB design includes Altium Designer, OrCAD, Pads, KiCad, Eagle, etc. NOTE: Designers should notify their contract manufacturer before PCB manufacture of the PCB design software version used to design the circuit as it helps prevent differences in their design.
Once PCB design has been accepted for manufacture, designers export the design to help their manufacturers. Extended Gerber is the most used application. The baby food ad campaign in the 1980s looked for beautiful infants, and this program produces some nicely made offspring. Gerber is also called IX274X.
Gerber was born in the PCB industry as the ideal performance format. Different PCB design software will call for various Gerber file production measures, all coding detailed important details including copper tracking layers, boiler drawing, apertures, notation of components, and other options. At this stage, all aspects of the PCB design are subject to checks. The program carries out design surveillance algorithms to ensure that no mistakes are undetected. Designers also examine the plan concerning track width, board edge spacing, trace and hole distance, and hole size elements.
After a careful inspection, the designers transmit the PCB file for production to PC Board Houses. To ensure that the design fulfills minimum tolerances during the production process, almost all PCB Fab Houses are running Design for Manufacturing (DFM) before the manufacture of the circuit boards.
Step 2: From File to Film
After designers release the PCB scheme files and manufacturers perform DFM inspections, PCB printing starts. Manufacturers use a particular printer known as the plotter to print circuit boards, allowing photographic films from the PCBs. Manufacturers use films to picture the PCBs. It’s a laser printer, but it’s not a traditional LaserJet printer. Plotters use unbelievably accurate printing technology for a highly detailed PCB concept video.
The end product results in a plastic sheet with a negative photograph of the black ink PCB. Black ink reflects the conductive copper portion of the PCB for the inner layers of PCB. The rest of the transparent part of the picture indicates the non-conductive material regions. The outer layers have the opposite pattern: transparent for copper, but black refers to the grafted region. The plotter produces the film automatically and securely stores the film to avoid unwanted interaction.
Per layer of PCB and soldering mask has a clear and black sheet of film. In total, four sheets are required for a two-layer PCB: two for the layers and two for the solder mask. Significantly, all films must match each other exactly. When used in harmony, the PCB alignment is mapped out.
Recording holes should be punched in all films, To ensure that all films are perfectly aligned. The precision of the hole is determined by changing the table on which the film is placed. The hole is punched when the minor calibrations lead to an optimum match. In the next stage of the image process, the hole will fit into the registration pins.
Step 3: Printing the Inner layers.
The production of films in the last step aims to map a copper path figure. Now is the time to print the figure on a copper foil on the film.
This phase in the production of PCBs prepares to produce actual PCBs. The fundamental type of PCB consists of a laminate board whose core material is epoxy and glass fiber, also known as substrates. Laminate is an ideal body to collect the copper that structures the PCB. The substratum material provides a robust and stable starting point for the PCB. On both sides, copper is pre-bonded. The method requires the removal of copper to expose the architecture of the films.
Cleanliness matters in the PCB building. The laminate on the copper side is washed and decontaminated. No particles of dust must settle on the laminate during this process. A wrong spot of dirt may otherwise lead to a circuit being short or open.
Next, the clean panel gets a photo-sensitive photo-resistant layer. The photo-resistance includes a photo-reactive chemical layer that hardens after ultra-violet light exposure. This ensures an accurate match between the photo films and the photo. The films are fitted on pins that keep them over the laminate plate.
The film and the panel line up and receive a UV light explosion. The light passes through the transparent sections of the film, hardening the photograph to withstand the copper below. The black ink from the plotter Prevents the light from reaching the areas not intended to harden and removed.
When the board is prepared, it is washed with an alkaline solution which unhardened removes any photo resistance. Another pressure wash is removed from the surface. Then the board is cleaned.
The product appears resistant to the copper areas that are supposed to stay in the final shape. A technician checks the boards to make sure there are no defects. All the resistance at this stage refers to the copper in the finished PCB.
This move refers only to boards with more than two layers. Simple two-layer boards skip for boiling ahead. More steps are needed for multi-layer boards.
Step 4: Removing the Unwanted Copper
With the picture resist removed and the hardened resistor that we wish to hold on the copper, the board moves to the next stage: the copper removal is unwanted. Much as the alkaline solution eliminated the resistance, the excess copper is eased by a more efficient chemical preparation. The copper solvent solution bath removes all exposed copper. In the meantime, the desired copper is wholly shielded under the hardened photo resistance coat.
Not every copper board is equal. Some heavier boards require more significant quantities of copper solvent and different exposure lengths. As a side note, heavier copper plates need extra care for the distance between tracks. Most basic PCBs have similar requirements.
Now that the solvent removes the unwanted copper, it resists washing off the preferred copper requires. Another solvent performs this duty. The board now shines only with the copper substratum for the PCB.
Step 5: Layer Alignment and Optical Inspection
With all layers clean and ready, the layers must be aligned to ensure that all are aligned. The inscription holes align the inner layers to the external layers. The technician puts the layers in a system called the visual punch, which allows an exact match so that the recording hole is punched correctly.
If the layers are set together, any defects on the inner layers cannot be corrected. Another computer automatically inspects the panels optically to confirm the complete absence of defects. The initial Gerber version, obtained by the maker, is the model. The computer scans the layers using a laser sensor and compares the digital image with the original Gerber file electronically.
If the computer is not consistent, the comparison appears on a monitor to evaluate the technician. After the inspection of the layer, it goes to the final stages of the PCB development.
Step 6: Layer-up and Bond
The circuit board takes shape in this phase. All the different layers are waiting for their union. They have to fuse with the layers ready and tested. Outer layers must be attached to the substratum. The process takes place in two steps: layer-up and connection.
The exterior layer is made of fiberglass sheets pre-impregnated with epoxy resin. The shorthand is known as prepreg. A thin copper foil often covers the top and bottom of the initial substratum containing the copper trace etchings. Now it’s time to sandwich them.
The fastening takes place on a heavy steel table and metal clamps. The layers are tightly fitted into the table pins. All have to match snugly to avoid alignment.
A technician starts by putting a layer of prepreg over the alignment basin. The substratum layer suits the prepreg before placing the copper sheet. Additional prepreg sheets are on top of the copper plate. Finally, the stack is completed by an aluminum foil and a copper press plate. Now it’s ready to be pressed.
The entire process is subject to an automated bonding press computer routine. The machine organizes the heating mechanism, the pressure point, and when the stack can be cooled at a controlled rate.
Next, there is some unpackaging. The technician unpacks the multi-layered PCB product with all the layers fused into a great sandwich of PCB glory. It is easy to remove the retention pins and remove the high-pressure plate. The PCB’s goodness comes out of its aluminum press plate shell. The copper foil, which is included in the operation, remains the external layer of the PCB.
Step 7: Drilling
Finally, holes in the stacking board are bored. The precision of the drill holes depends on all components to come later, such as copper links through-hole and guided aspects. The holes are boiled to a width of the hair – the drill has a diameter of 100 microns, and the typical hair is 150 microns.
An x-ray locator detects the correct drill targets to locate the position of the drill targets. Proper recording troubles are then bored to secure the stack for the sequence of basic trousers.
Until drilling, the technician positions a buffer board under the drill’s goal to ensure that a clean bore is implemented. The exit material avoids unwanted tears at the exits of the exhaust system.
Every micromovement of the drill is controlled by a computer – a product that decides the machine’s actions will naturally depend on computers. The computer-driven system uses the initial drilling file to locate the correct boor spots.
The drills use air-powered spindles at 150,000 pm. You may think boiling takes place in a flash at this speed, but there are many trolls to boil. An average PCB contains well over 100 bore points intact. Each person needs his own particular time when exercising, so it takes time. The holes later include the vias and the mechanical PCB fittings. The final attachment of these sections takes place later, after plating.
If the boiling is complete, a profiling tool removes the additional copper that lines the edges of the production panel.
Step 8: Plating and Copper Deposition
The panel shifts to the plating after drilling. The method fuses the various layers with chemical deposition. The panel is subjected to a series of chemical baths after a thorough washing. A thin layer of copper over the panel’s surface – about one micron thick – is deposited during the baths during a chemical deposition process. The copper enters the newly drilled trousers.
The internal surface of the holes before this step reveals the glass fiber material comprising the interior of the panel. The copper baths cover the walls of the holes. By the way, the whole panel receives a new copper layer. The new holes are, most importantly, sealed. Computers monitor the entire dipping, deletion, and processing process.
Step 9: Outer Layer Imaging
In Step 3, we used the panel to avoid photography. We do it again in this step, only this time we are photographing the outer layers of the PCB design. We start with layers in a sterile room to prevent pollutants from sticking to the layer surface and then add a photo resistance layer to the panel. The prepared panel enters the yellow office. UV light impact resistance to photography. Yellow light wavelengths do not hold enough UV levels to resist the photograph.
Pins protect black ink transparencies to avoid the panel being misaligned. A generator blows them with high UV light, which hardens the photo tolerance, with panel and stencil in contact. The panel then passes through an unhardened resistor removal machine shielded by the opacity of the black ink.
The mechanism is a reversal of the inner layers. In the last point, the outer plate was inspected to ensure that all the unwanted photographic resistance had been eliminated.
Schritt 10: Plating Step 10
We go back to the boardroom. Like in step 8, we electroplate the panel with a thin copper sheet. Copper electroplate receives the exposed parts of the panel from the outer photo resistant level. After the initial copper plating baths, the panel is usually plated in tin, which allows the removal of any left copper on the removal surface. The tin guards the part of the panel to be covered with copper during the next etching point. Etching eliminates from the panel the unwanted copper foil.
Step 11: Final Etching
During this stage, the tin protects the desired copper. Unwanted exposed copper and copper are removed from the residual resistant sheet. Again, chemical solutions for the removal of excess copper are applied. During this time, the tin protects the precious copper.
The conducting areas and connections are now correctly described.
Step 12: Solder Mask Application
The panels will be washed and coated with an epoxy solder mask ink before the solder mask is applied to both sides of the surface. The plates obtain UV light, which passes through a picture film with a solder mask. The portions covered remain unhardened and removed.
Step 13: Surface Finish
To add the additional soldering capability to the PCB, we chemically plate it with gold or silver. At this point, some PCBs also receive hot air pads. The leveling of hot air produces uniform mats; this method contributes to surface finishing. PCBCart can process various surface finishes to the unique requirements of its customers.
Step 14: Silkscreen
The almost finished board receives ink-jet writing on its surface to indicate all essential PCB data. The PCB finally passes to the last coating and treatment point.
Step 15: Electrical Test
A technician conducts electrical checks on the PCB as a final precaution. The automated process confirms the PCB’s functionality and its compliance with the original specification. At PCBCart, we have an advanced variant of the electrical test Flying Probe Testing that relies on moving samples to test any net’s electrical output on a bare circuit board.
Step 16: Profiling and V-Scoring
Various boards are cut out of the original panel. The system used focuses on the use of a router or a v-groove. A router leaves little tabs along the board’s edges, while the v-groove is cutting diagonal channels along the two sides. Both ways allow the boards to pop out from the panel easily.
As you can see, a lot of effort goes into the production of printed circuit boards. You have to pick up a manufacturer with a high level of experience and focus on quality at every point to make PCBs produced with your expected quality, efficiency, and durability.
VictoryPCB is one of the most experienced Chinese customized service providers for PCB development. Understanding that our customers’ success measures our performance, we concentrate on the attention and attention to details required for every PCB production phase. We also have vacuum packing, weighting, and shipping to ensure that your PCB order is secure and damage-free. We have so far printed platforms for companies of all sizes from more than 80 countries, and in the coming years, our goal is to supply our manufactured PCBs to every corner of the world.
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