Manufacturing PCBs has allowed engineers to connect components in a circuit more organizedly, eliminating the need for many wires to cross each other, which may lead to accidents.
Notice that modern technology allows for large-scale production, which significantly reduces costs.
This article introduces you to learn more about PCBs, the materials used in manufacturing them, the price, and the process they undergo.
Contents
What Is A PCB And How Is It Made?
A Printed Circuit Board (PCB) is a board made of fiberglass, laminate materials, or composite epoxy.
It has conductive pathways that connect to different components, such as resistors, transistors, and integrated circuits.
It supports and connects electrical components via conductive tracks or pads. Electronic components are soldered onto the PCBs to perform some specific functions.
Figure 1 PCB Board
The PCB Substrate
We have a flexible. PCBs and FPCB are made of layers of materials, including the base material (referred to as a substrate), which determines whether a PCB is rigid or WellPCB offers DC motor controllers in domestic and international markets. Also, the substrate used determines the temperature range that your PCB can withstand.
The substrate is often made by laying out the material directly, spraying it with epoxy resin, and rolling it several times to an acceptable thickness. Another critical consideration is PCB’s permittivity/permeability. This feature is of the essence when designing boards for devices with high-frequency signals.
The Copper
For a printed circuit board to work, it must have either a single layer or multi-layers of copper. Manufacturers may choose to put the layer of copper on the top or both sides of the substrate. It is also possible to have several layers which alternate between the substrate material and the copper.
We have plenty of PCBs out there with many layers of copper. Some of them have more than 16 copper layers.
Usually, the thickness of copper is thinner than the substrate used. The primary role of copper is to carry electrons from one point to another. Manufacturers bind the copper to the substrate by applying a combination of heat and pressure.
This binding process secures the bond between the copper and the substrate. This process makes it resistant to breakage during the drilling process. Copper is also one of the materials that it can recover through a recycling process.
The PCB Soldermask
After the substrate and the copper layers have been fused, it is necessary that the plating gets protected to reduce the chances of copper oxidizing and rusting in a way that can damage the PCB. It is, therefore, to use a solder mask when making additional layers to protect the PCB.
The substrate is typically green in color. But then, the manufacturer may choose any other color depending on their need.
PCB Manufacturing Process
The process of manufacturing PCBs starts by assembling the required material (including the substrate and copper). The substrate is then attached to the copper by applying pressure and heat.
Lastly, the process also involves creating tracks, removing unwanted copper through an etching process, and testing the board for flaws before production.
Double-Sided PCBs Fundamentals Introduction
PCB boards have increasingly become part of our day-to-day electronics. The boards provide an interface on which they can solder components.
PCBs may be single, double, or multi-layered. Single-sided PCB boards are cheap, but they cannot be deployed in complex situations. It has forced manufacturers to design and manufacture double-sided PCBs that can be used in high-density and complex cases.
2.1 What is a Double-Sided PCB
Figure 2 Double Sided PCB
A double-sided PCB is a type of PCB that offers engineers the flexibility of interconnecting circuits and components on either side of the board. It allows the user to have components soldered on both the bottom and the top side of the PCB.
They enable the manufacturers to design complex panels that can accommodate more features for use in difficult situations.
Other than providing interconnection flexibility, the boards also eliminate electromagnetic interference. This ability makes designing complex circuits a lot easier. The double-sided PCBs have also made it possible to use PCBs in higher technology applications.
Allowing for top layer routing and tracing to the bottom layer has made PCBs more valuable than before.
2.2 Advantages of Double-Sided PCBs
Double-sided PCBs offer engineers more flexibility. They also house increment in the circuit densities over time. These factors do not apply to engineers working on single-sided PCBs. Single-Sided PCBs have limited space to fit the components.
Secondly, double-sided PCBs are nowadays cheaper and do not squeeze much from your daily budget.
Lastly, since more parts can be populated in a smaller area, double-sided PCBs are small in size and can be utilized to manufacture smaller devices.
PCB Copper Thickness
PCB boards allow for the flow of current between components. They do this by ensuring that the routes on the PCB are not overlapping and have enough space between them.
Overlapping of wires can cause short circuits and so using a PCB board with sufficient copper thickness eliminates this problem. Typically, PCB copper thickness is measured in ounces and determines whether the courses can do the job it is designed for or not.
3.1 PCB Copper Thickness
Copper thickness, therefore, refers to the results you get when 1oz of copper is compressed over an area of one sq. Ft. of PCB. When designing a PCB, the engineers must convert ounces to mills to help them create the PCB.
Figure 2 gives an overview of what copper and PCB layers appear like in the form of various layers.
3.2 Designing Copper Tracks
Engineers must always remain alert when designing PCBs. They need to ensure that the PCB thickness is enough to meet all that a circuit needs.
As an engineer, you should keep the thickness at 1oz. To ensure that the PCB can accommodate the specified amount of current that should flow through it.
Circuits requiring more current must increase their copper thickness to minimize resistance.
PCB engineers can calculate the amount of copper thickness needed when designing a circuit to perform a specific function.
The thickness of the copper can sometimes affect the cost of the PCB board.
It also determines how easy it is for the designer to remove the excess copper by etching the PCB.
Thus, designers of PCB must evaluate thickness before designing a PCB to be put to a specified application.
Heat Sink PCB-The Rules You Need To Know
As PCB technology advances, new challenges emerge, and so the engineers must work round the clock to overcome the difficulties.
The generation of heat that leads to increased temperatures on boards is an issue that most engineers strive to overcome. This challenge has forced designers to think outside the box and find ways to minimize heat generation and electrical loss.
The invention of the heat sinks is one such attempt to regulate circuit temperatures. Heat sinks help to distribute heat evenly and minimize excessive concentrated temperatures.
For instance, in circuits that involve high-speed microprocessors, a lot of heat is dissipated. Without heat sinks to absorb the heat, high temperatures are capable of damaging the component.
The ICs, in particular, generate a lot of heat and require heat sinks to absorb and channel the excess heat.
4.1 Metallic Heat Sinks
This type of heat sink can be attached to a board by tightening it with a screw through the hole. The heat sink may be pasted on the body using epoxy or even thermal tape in some other cases.
When the heatsink comes with springs and clips, it is possible to fit it into the component that heats up.
Notice that a heat sink on PCBs plays a critical role, mainly where a PCB is used in circuits with a massive flow of current. For instance, discrete semiconductors such as IGBTs, TRIACS, and MOSFET generate much heat, which must find its way out of the PCB (often via a heat sink).
4.2 SMD Components with built-in Heat Sink
We have plenty of SMD components that come with inbuilt heat sinks. Such members include the PMICs and MOSFET. These devices have an integrated heat sink attached to a circuit and then connected to a drain.
4.3 Heat Sink PCB Thermal Design Considerations
From the above discussions, it is evident that power devices must have a proper PCB layout and heat sink(s) to take care of thermal issues that may arise when the device is in use.
4.4 Design guidelines to consider when dealing with heat sinks
• For a heat sink to dissipate one Watt of power at a temperature of about 40℃, it should have a cross-section of 2.4 in2. If an external cooling fan is used, the values reduce to about 1.2 in2 per watt.
• If the two proposed methods fail to work, it is recommended that you use generic heat sinks.
Also, it will extend the copper to the edges of the board. • Notice that the above parameters assume that copper layers will generally be coupled with components that generate heat. The argument then implies that the copper layer will behave as the thermal layer of your PCB.
• When more than 1 component that generates much heat is to be used on PCB, it is recommended that you place them a few inches away from each other. It allows the PCB to be heated evenly.
• The heat transfer is always higher when the PCB has more vias. The vias are in thermal contact with the parts of the component that is generating heat.
• In the case of high-powered applications, it recommends that you consider using PCBs with an increased copper weight between the planes.
Manufacturing Costs Breakdown
PCB assembly and production are tedious activities that entail many steps. They involve collecting the materials, preparing them, and fabricating them into PCBs.
It also involves etching, laminating, drilling, and packaging the PCBs. Each of these steps has a cost, which is the total cost of manufacturing the PCBs, which must be included in the final selling price.
How To Make PCB Manufacturing Cost Breakdown from each part?
5.1 The Cost of Material
The cost of raw materials is the primary factor determining the final price of PCBs.
To understand the cost of manufacturing, we must consider the layers of a PCB, the material used in manufacturing it, and its size.
Gold, nickel, copper, silver, fiberglass, lead, epoxy resin, and various chemicals are some materials that it must use in manufacturing PCBs. You also need to estimate the number of components that need to be assembled.
Also, the type of PCB to be assembled is critical as it helps determine the final cost of the PCB. For instance, manufacturing a double-sided PCB is more costly than a single-sided PCB.
Double-sided PCBs use more solder and require that you make use of the SMT machine programming. These requirements increase the cost of these PCBs. Similarly, manufacturing multi-layered PCBs is more costly than the production of double-sided PCBs.
Notice that the essential items that increase the cost of PCBs are not just limited to the price of the material but also the thickness of the PCBs, the Impedance they should come with, and the diameter of the holes.
The cost also needs to include the components and transport the PCB distance. Other peripheral factors must come into play when computing the value of the PCBs.
The thickness of the copper used is one of the factors that affect the production cost. Using thick copper increases impedance and allows the PCBs to be deployed in areas that require more current.
Other external factors, such as energy, water, and transportation costs, may increase the cost of production. These must also be included in the computation of the cost of producing PCBs.
5.2 Cost of Labour
Notice that the cost of labor is also critical in determining the final price of manufacturing PCBs. Manufacturers will also have to include other overhead expenses in the final cost of PCBs.
These costs are expenses from the labor working on the fabrication of a PCB.
It must consider the cost of equipment, security, lighting, water, and other small overhead expenses in determining the final cost of producing every PCB.
Other additional overheads such as treatment of wastewater system, approvals, zoning, and permits should also be part of the billing of PCBs.
5.3 Board Size
A panel is one of the essential raw materials used in producing printed circuit boards. The size of the panel used is necessary when calculating the overall cost of a PCB. Boards that take up a lower panel area will cost less. Also, those that use panels that fit better will be less costly.
5.4 The Number of Pieces Produced
The quantity of the pieces required is critical because it determines the method of production to be used. Mass production of PCBs involves the use of efficient and automated processes that reduce the cost significantly.
5.4 Lead Time
Lead time is the time it takes to manufacture a PCB. We can provide both regular delivery service & express service; expedited boards can be shipped out within 24-48 hours. You can choose a suitable service according to your schedule.
We often try our level best to make PCB Manufacturing Cost Breakdown without compromising our quality.
The delivery time of our factory is also assured.
We have other Ultimate Guides to reducing PCB Costs. If you are interested, you can check them out here.
Conclusion
Having taken you through what PCBs are and some of the factors that determine the ultimate cost of PCBs, I bet you are now better placed to make your PCB order.
We simplified this process. Just visit wellpcb.com and place an online order.
Please note that without special remarks, all the price we quoted is based on the standard delivery.
So, you need to indicate our online quote system or contact us about an expedited order. In so doing, your order will be processed as a top priority request. (Please note that our current products will affect the time, call us if time is of the essence).
For the Special board, please do circuit board shopping; various things might get you confused. Whether you are going for a single-sided PCB, a double-sided PCB, or any other type of PCB, You can contact us for details:
- Special Material Requirements
- Shielding Layers
- Blind and or Buried Vias
► Rigid-flex constructions with more than 2 Flex Layers
► Special Surface Treatment
Why Choose needs to know about ordering custom PCB Circuit boards online.
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WellPCB, registered in Australia, is a daughter company of Uniwell Circuits Co., Ltd, which has two modern PCB factories founded in April 2007.
If you are interested, you can visit our homepage.
PCB Assembly Turnkey Services. As WELLPCB, we aim to meet the goal of producing high-quality and low-cost PCBs. We are focused on Printed Circuit Board Fabrication and Bill Of Materials (BOM) of a PCB to get fitted aboard. -We are dedicated to delivering faster and easier ordering from customers worldwide.
With brand new equipment and a total production area of over 10,000 square meters, one can produce 100,000 square feet of 2-32-layer PCBs and deliver over 5,000 varieties monthly.
We can provide quick turns to meet 24-48-hour delivery for double-sided PCBs, 72 hours for four to eight layers, and 120 hours for ten layers or higher PCBs.
