PCB Manufacturing

What are the Steps of Making a PCB Circuit Board? Ultimate Guide

Making a PCB Circuit Board

A Printed Circuit Board is a component of electronic gadgets that keeps the gadget running with electrical and mechanical support. PCBs are essential to the proper operation of many electronic devices, including computers, smartphones, and various machinery. The production of PCBs involves multiple intricate procedures that contribute to the overall development of the board.

To guarantee that there are no flaws in the PCB, every crucial step is carried out with extreme care by professionals. By laminating copper sheets onto a non-conductive substrate, they create conductive paths and signal traces that are used to link electronic components. If you are wondering how to make a PCB circuit board, take a look at the steps explained below.

Printed Circuit Board with Gold Fingers

The following are the detailed explanations of all these steps. We hope after reading this article, you will know how to make a PCB or printed circuit board.

Step 1: Design

People know how important PCBs are in electric gadgets, so it is no wonder that they want to learn all about how to make PCB circuit board. The design phase is the first in the PCB manufacturing process because this schematic layout will serve as a guide throughout the entire procedure. The board layout is usually completed with programs, and a particularly popular circuit board design program is known as Gerber which is an excellent resource for designing circuit boards since it can be utilized as an exporting program too. Additionally, it keeps records of crucial information that developers require, such as drilling sketches, wire monitoring sections, and quantity of soldering shields required, along with additional information. The program performs supervision procedures over the entire schematic to guarantee no errors occur once the printed circuit board (PCB) template has been successfully and correctly captured. At this point, thorough inspections are also performed on the board dimensions, border positioning, tracing and piercing distance, and the dimension of holes.

Step 2: Design Review

This can be an important step in the technique of creating printed circuit boards. If you are interested in learning how to make a PCB, pay attention to this issue. It comprises verifying that the schematic conforms with the specifications and checking them for any potential errors or flaws, such as improper arrangement of the PCB and production regulation infringement. A technician examines each component of the printed circuit board (PCB) layout throughout a design evaluation to make sure the frameworks are accurate and no components are omitted. The moment the designer gives his or her approval, the production may move forward with printing.

Also read: What is a PCB and How Does a PCB Work?

Step 3: File to Film

The printed circuit board manufacturing can begin once engineers create the PCB layout designs and producers do the design for manufacturing inspection. Producers manufacture components on sophisticated printers that produce graphic plates of the boards that the producers will employ to reconstruct the PCBs. Planners use incredibly fine printing equipment to create a highly comprehensive image of the PCB layout, and the end result is a piece of plastic imprinted in black ink that includes a negative image of the circuit board. The conductive metal parts of the circuit board in its innermost layers are identified by black ink, while the transparent area of the image indicates non-conductive substance sections. The arrangement is reversed in layer that surrounds it, where copper is represented by translucent sections and black indicates the area that will be scraped out afterwards. The printer instantly develops the image and stores it securely to prevent unauthorized access. Every single layer of the soldering mask and the printed circuit board is given its film strip and a two-layer printed circuit board requires four pieces in total.

Step 4: Inner Layer Printing

The basic components of printed circuit boards (PCBs) are laminated panels and the primary substances are epoxy resin and glass fiber, also known as substrate substances. The base gives the PCB a stable foundation, and copper is utilized to construct the PCB which has two overlapping sheets. However, the copper needs to be peeled in order to see the design underneath the plates, and to separate the copper from the lamination, a cleaned environment is essential. You must make certain that the printed circuit board is free of contaminants throughout this operation to prevent the electronic component from shorting out.

Since the photo-sensitive substance employed to create the photoresist material will harden when subjected to UV rays, the photoresist film is employed after this stage is completed. Whenever these sheets are arranged on the lamination of the surface, they have to line up and follow this stage. The black ink on the reflective screen absorbs ultraviolet (UV) rays, stopping the copper beneath from solidifying, and the material below the black ink lines won’t harden. Once the translucent zone becomes harder from ultraviolet (UV) radiation traveling across it, the excess photoresist material will be destroyed. This entire process is an important step in how to make a PCB board.

Step 5: Removing Unwanted Copper

After the coating of photoresist has been eliminated and the bare metal has been thoroughly cleaned with the copper cleaning fluid, the undesired copper must be discarded. Beneath the hardened section, the necessary copper remains totally shielded. Each of the boards is not created identically, and with certain heavy boards, varying treatment durations and solution amounts are required. Similar specs are used by most common printed circuit boards. After removing the unwanted copper, the stiffened shield must be eliminated with another type of solvent previously used. In PCB manufacturing, removing unwanted copper should not be ignored as to how to make a PCB board.

Step 6: Layer Alignment

Matching apertures are required to guarantee coating compatibility following preparation and cleaning of each level. The marking holes line up between the outer and inner sections, and the professional places multiple layers into an instrument to accurately drill the marked openings. Once all of the layers are built, errors that occur on the innermost ones cannot be corrected. This is why an additional device constantly uses optical methods to check the screens to make sure there aren’t any faults present. The producer’s initial layout serves as the basis for the current version and once various components have been scanned by an optical detector, the gadget digitally matches the computerized picture to the source files. If the equipment finds differences in the illustrations, the engineer can assess it by spotting the information on a display.

Step 7: Layer up and Bonding

Sheets must be layered on top of the foundation in order for them to combine permanently. The outermost layer is made of prepreg, and the top and bottom of the substrates will be coated with a tiny amount of copper that has been etched with tracing. A rigid board with metallic hooks is used for bonding every layer, and all of them are secured to avoid motion during alignment. A coating is applied to the aligning region, and the base layer and the copper sheet positioning come next. A program can computerize the bonding and compression process, which involves generating heat for the bonds and regulating its rate of cooling.

Ceramic PCB Circuit Board

Step 8: Laminating the PCB Layers

The PCB laminating process takes place only after it is determined that the layers are defect-free. Metal clamps are employed on a specialized press table to weld the layers together, and each layer has a certain type of pin to fit onto the table. The alignment basin of the table gets covered with a layer of prepreg, which is pre-coated epoxy resin, and the prepreg is then covered with a substrate layer, which is followed by a layer of copper foil and further prepreg resin sheets. After that, a pressing plate which is an extra copper layer is positioned on the outside, and a pressing device is used to seal the two layers firmly. The screws are driven into various layers to ensure that they are securely placed and attached and the successive layers are subjected to heat and pressured by two hot slabs. As a result, the material within dissolves and combines with the force of the pressure and bonds multiple layers to one another. After all of the layers have been properly bonded together and the leading pressing board and connectors have been stripped away, the printed circuit board may be easily detached.

Step 9: Drilling

Accurate drilling is necessary for any element insertion that is planned for at some point, such as linking through apertures and conducted features. To establish the boring positions, an X-ray locator beam finds the proper boring locations for drilling, and the structure is fastened for greater precision cuts. Before the drilling process, the professional places an object of cushioning substance underneath the instrument to ensure an uncontaminated hole is generated. Each motion of the hole-making process is regulated by an operating system, but the computer device uses the data file from the initial blueprint to figure out where to penetrate. The openings are subsequently filled with the PCB’s physical attachment points which are then plated and fastened. After the procedure for drilling is complete, the excess copper that wraps along the edges of the screen is removed using a cutting machine.

Step 10: Plating

Chemical solution is used in the procedure of plating where the panel gets thoroughly cleaned before going through the process. The newly created openings are then stuffed with the metal copper, and a thin layer is applied to the top of the panel using the technique of chemical layering. Before this stage, the inner portion of the aperture shows the material which makes up the panel’s interior. Otherwise, the copper plate completely covers the openings. Interestingly enough, at this juncture, every single panel receives a new layer of metal plating and it is essential that the newly created gaps be covered up, and machines control every step of the cleaning operation to ensure accuracy. Typically, plating plays an integral part in how to make a PCB.

Also read: Common Mistakes to Avoid in PCB Assembly and Manufacturing

Step 11: Outer Layer Imaging

The board gets covered with another layer of photoresist at this stage, which is comparable to step four, but this time the treatment just covers the outer layer. Following this coating, the board is transported for imaging, where the photoresist is hardened by UV radiation, and the undesired portions are subsequently removed. After this, a thin coating of copper is plated outside, much like it was done inside, and to help prevent the copper from being etched off, a thin layer of tin is also applied.

Step 12: Outer Layer Etching

The tin plating shields the necessary copper from the etching chemical solution during the outer layer etching. You may remember from earlier that the outside layers utilize transparent ink for non-conductive regions and black ink for conductive areas, while the interior layers do the opposite. Because of this, the outer layer’s copper has light ink, enabling the tin guard to shield it.

Step 13: Solder Mask

All the panels are thoroughly cleaned before the solder mask is put on each panel. The necessary solder mask is then baked into the board, and a concentration of UV light shows where the solder mask has to be removed. In addition to providing protection from oxidation and corrosion, the solder mask gives a circuit board its typical green hue.

Step 14: Surface Finish and Silkscreen

Manufacturers chemically treat the PCBs with gold or silver to increase their solderability, and during this phase, certain PCBs additionally acquire hot air-leveled pads. Uniform cushions are the outcome of hot air solder leveling, and the creation of surface polish is the result of such a procedure. All the important information about the PCB is written in ink-jet ink on the almost finished board.

Step 15: Electrical Reliability Test

You need to understand the need of an electricity stability assessment now that you understand how to make PCB board. To make certain the circuit board meets the required functioning standards, it must be electrically tested. When executing electricity examination, which mostly consists of checking the board for network consistency, specifications for the electrical inspection of printing panels need to be followed. While the circuit integrity analysis searches for any electrical interruptions in the printed circuit board, the network separation check searches for circuitry faults and assesses the electrical isolation qualities of different circuit parts. Apart from verifying efficiency, the evaluations also seek to validate the degree to which the initial board layout was adapted to the fabrication procedure.

Conclusion

As mentioned above about how to make a PCB, many steps are involved in making a PCB board. This blog post offers an ultimate guide to how to make printed circuit board. Briefly, it includes design, assembly, manufacturing and inspection.

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