Co je to výroba desek plošných spojů?

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Co je to výroba desek plošných spojů?

FR-4

FR-4 je nejběžnějším substrátem používaným při výrobě desek plošných spojů. Je vyroben ze skleněné tkaniny napuštěné hybridní epoxidovou pryskyřicí. Má vynikající elektrické, mechanické a tepelné vlastnosti, takže je oblíbenou volbou pro různé aplikace. Mezi typická použití desek plošných spojů FR-4 patří počítače, komunikace a letecký průmysl. S tímto materiálem se snadno pracuje a konstruktérům nabízí řadu výhod.

FR4 je ideální materiál pro vícevrstvé desky s vysokou hustotou. Mezi jeho výhody patří nízká roztažnost a vysoká tepelná odolnost. Je vhodnou volbou pro aplikace, kde teploty přesahují 150 stupňů Celsia. Je také známý pro své snadné zpracování a elektrické vlastnosti.

FR-6

FR-4 je levný, nehořlavý průmyslový laminát, který má papírový substrát a pojivo z fenolové pryskyřice. Je běžnou volbou pro lamináty desek s plošnými spoji. Je také levnější než tkané skleněné tkaniny. Jeho dielektrická konstanta je 4,4 až 5,2 při frekvencích nižších než mikrovlny, při vyšších frekvencích postupně klesá.

Výroba desek plošných spojů vyžaduje různé substráty. Nejčastěji se používají materiály FR-4 a FR-6. Mezi další běžné materiály patří G-10, hliník a PTFE. Tyto materiály se používají pro své mechanické a elektrické vlastnosti a lze je tvarovat podle konkrétních specifikací.

Materiál FR-4 se používá při výrobě desek plošných spojů pro svou nízkou cenu a univerzálnost. Je to elektrický izolant s vysokou dielektrickou pevností a vysokým poměrem pevnosti k hmotnosti. Je to také lehký materiál a odolává vlhkosti a extrémním teplotám. FR-4 se obvykle používá pro jednovrstvé desky plošných spojů.

FR-8

Pro výrobu desek plošných spojů se používá několik různých materiálů. Každý materiál má jiné vlastnosti a jiný soubor vlastností může ovlivnit výkon desky. Obecně se desky plošných spojů dělí do tří různých tříd, třídy 1 a třídy 2. Desky plošných spojů třídy 1 mají omezenou životnost, desky plošných spojů třídy 2 mají prodlouženou životnost a desky plošných spojů třídy 3 mají vysoký výkon podle potřeby a desky plošných spojů třídy 3 nesnesou poruchu.

Prvním krokem při výrobě desek plošných spojů je jejich návrh. To se obvykle provádí pomocí počítačového programu. Pro určení tloušťky různých vrstev, například vnitřní a vnější vrstvy, je užitečná kalkulačka šířky stopy. Vnitřní a vnější vrstvy se obvykle tisknou černým inkoustem, aby se vyznačily vodivé měděné stopy a obvody. V některých případech se používá barva pro označení povrchové úpravy součástek.

FR-4 + FR-4 + FR-4

FR-4 je běžný substrát používaný při výrobě desek plošných spojů. Skládá se ze skleněné tkaniny napuštěné hybridní epoxidovou pryskyřicí. Jeho vynikající elektrické, tepelné a mechanické vlastnosti z něj činí ideální materiál pro desky s plošnými spoji. Tyto desky se používají v řadě průmyslových odvětví včetně počítačů, komunikací, leteckého průmyslu a průmyslového řízení.

Při výběru materiálu desky plošných spojů zvažte množství vlhkosti, které deska pravděpodobně absorbuje. Absorpce vlhkosti je měřítkem toho, kolik vlhkosti může deska plošných spojů zadržet, aniž by došlo k její degradaci. FR4 vykazuje velmi nízkou absorpci vlhkosti, v průměru 0,10% po 24 hodinách ponoření. Díky nízké absorpci vlhkosti je materiál FR4 ideální volbou pro výrobu desek plošných spojů.

Materiál FR4 sice není jediný materiál, ale jedná se o skupinu materiálů označenou Národní asociací výrobců elektrotechniky (NEMA). DPS FR4 se obvykle skládají z tera-funkční epoxidové pryskyřice a tkané tkaniny ze skleněných vláken s výplní. Tato kombinace materiálů poskytuje vynikající elektrický izolant a vysokou mechanickou pevnost. Desky s plošnými spoji FR4 se používají v různých oborech a patří mezi nejběžnější desky s plošnými spoji v mnoha průmyslových odvětvích.

Jak vyhledat desku plošných spojů

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Jak vyhledat desku plošných spojů

There are several ways to look up a circuit board and determine its components. The first step is to know the components’ names, which are part numbers. Next, determine which type of component it is. These components can be resistors, capacitors, inductors, or potentiometers. The resistors will be marked with an ohm measurement mark. The ohm symbol looks like the Greek letter Omega. One example is 100MO, which stands for one hundred megaohms. Other components that may be on a board include oscillators and diodes, which are marked with the letter D. Relays, on the other hand, are usually marked with a K.

Part Numbers

Part numbers are used to identify parts on printed circuit boards. They make repairs or replacements easy, and help ensure the integrity of electronic devices. Circuit boards are manufactured over months or years, and their designs often change. Some boards also include individual serial numbers, which help technicians identify the right part in a problem or repair.

Copper layer

When designing a circuit board, it is important to consider the thickness of the copper layer. Depending on the amount of current to be transported and the type of circuit, copper thickness may vary. For instance, PCBs with high current levels require more copper than a low-voltage board. Usually, copper layer thickness is specified in ounces per square foot. However, some PCBs use two or three ounces per square foot for high-power circuits. A standard ounce-per-square-foot copper sheet is 34 micrometers thick.

Substrát

Circuit boards are commonly made of different types of substrates. The type of material a board is made from will determine its performance. Substrates are usually selected based on their electrical properties, environmental properties, and form factor.

Power rails

When building circuits, you will often need to connect power to different locations. This is made easy by the power rails. Each power rail is labeled with + or -, and may have a red, blue, or black stripe.

Tranzistory

If you want to make sure that a transistor is compatible with a certain circuit, you need to know how to look up its part number on a circuit board. Most transistors have a part number, which usually starts with “2N.” This part number usually indicates the type of transistor and is not necessarily a standard format.

LEDs

LED PCBs are one of the most popular types of circuit boards. They are used in virtually every type of circuit today. To look up a circuit board, you first need to download the Kicad software. Once you’ve downloaded it, you’ll need to unzip the Kicad design files. These files include the Pro, CMP, Kicad PCB layout, and schematic.

Resistors

Resistors on a circuit board play a critical role in a circuit. If the resistors are damaged, it can lead to a failure. When you choose a resistor, you need to consider its maximum current carrying capacity. If the resistors are too low in this capacity, they will not protect your electrical components from high current fluctuations. High power resistors are available for high-current applications.

Induktory

There are a few key properties to know when choosing inductors. First, you need to know the self-resonant frequency of the inductor. It must be at least 1.5 times the operating frequency. Also, you need to know the DC resistance and impedance. These properties are critical when choosing inductors that will filter electromagnetic interference.

What Is PCB Assembly?

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What Is PCB Assembly?

PCB assembly is a complex process that involves the building of circuit boards. Circuit boards are typically made from plastic and require a high level of precision. The process of assembly is often performed by hand. However, some circuit boards are so intricate that a machine is required to handle them. This process can be costly and time-consuming.

Osazování desek s plošnými spoji

Printed circuit board assembly is an essential process in the creation of electronic devices. It is a process in which printed circuit boards are placed onto a non-conductive substrate. Then, components are attached to the PCB. Depending on the type of board and its application, different processes are used.

One of the most important factors in PCB assembly is the component footprint. Ensure the footprint matches the datasheet exactly. Otherwise, the component will be positioned improperly and receive uneven heat during the soldering process. In addition, a wrong footprint can cause the component to stick to one side of the PCB, which is not desirable. Moreover, the wrong land pattern can cause problems when using passive SMD components. For example, the width and magnitude of the tracks connecting pads can affect the soldering process.

The process of PCB assembly starts with printing a circuit board design onto copper-clad laminate. This is followed by etching the exposed copper to leave a pattern. Upon placement of the components, the circuit board is then placed on a conveyer belt. After the board is placed in a large over, it undergoes reflow soldering. Reflow soldering is an important step in PCB assembly. The reflow process involves placing the circuit board on a conveyor belt, and then putting it inside a heated chamber. During this time, solder melts and shrinks.

Techniques

There are several different techniques for PCB assembly. One of these techniques is automated optical inspection, which incorporates a machine with cameras to examine the boards from various angles and detect any errors. Another technique is visual inspection, which involves a human operator checking the boards manually. These techniques are useful for PCBs made in small quantities, but they have their limitations.

Orienting the parts in the same direction is another technique for making the PCB assembly process faster and easier. This method helps minimize the chances of cross-connecting components, which can lead to soldering problems. Another technique is placing the edge components first. The reason for this is to guide the layout of input connections on the board.

Costs

The costs of PCB assembly vary greatly between companies. This is because the basic materials used to manufacture PCBs are expensive. In addition, some companies will charge much more than others for the same PCB assembly services. However, the quality of the finished product remains unaffected. So, if you are unable to afford the high cost of PCB assembly, you can always look for cheaper alternatives.

PCB assembly costs are dependent on the volume of PCBs that you need assembled. Low-volume orders will incur higher costs, while medium-sized orders will incur lower costs. Moreover, the quality of the design and components used in the PCB assembly process will also play a role in determining the overall cost.

Downfalls of manual pcb assembly

Manual PCB assembly is a labor-intensive process that requires skilled technicians. It also takes a lot of time and has high risk of human error. For this reason, manual assembly is not recommended for large-scale PCB assembly projects. It is also not an ideal option for some components, such as fine-pitch pins and dense SMT parts.

Another disadvantage of manual PCB assembly is the lack of automation. Even the most seasoned hands will struggle to achieve the same level of precision as a machine. It is also difficult to achieve consistent and residue-free soldering. As a result, hand-made boards have inconsistent quality. Moreover, smaller components are more difficult to assemble by hand.

In-Circuit testing

In-Circuit testing (ICT) is a process in which the PCB is put through a number of steps in order to ensure that all components are properly seated. It is a very useful test, but has some limitations, such as limiting test coverage. Some PCB components are too small for this method, or have a large number of components. Nevertheless, this method can provide high levels of confidence in the build quality of the board and its functionality.

PCBAs can be tested in many different ways, including in-circuit testing, which uses electrical probes attached to specific points on the board. The probes can detect component failures such as lifts, shifts, or bad soldering. They can also measure voltage levels and resistance, as well as other related factors.

How Are Printed Circuit Boards Made?

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How Are Printed Circuit Boards Made?

One of the most important components of any printed circuit board is the connection holes. These holes are drilled in a precise pattern to allow the circuits to connect to one another. Automated drilling machines utilize numerically controlled drill files, also called excellon files, to determine where to drill and how big to make the holes. Depending on the PCB’s structure, drilling can be done one layer at a time or in layers prior to lamination.

Multi-layer PCBs

A multi-layer PCB is a printed circuit board with more than three layers. These boards are used in a wide variety of devices, from home appliances to medical devices. Typically, a board needs at least four layers to function properly. This technology is becoming more prevalent in household appliances and is becoming more common in medical devices, such as X-ray machines and CAT scan equipment.

The process of multi-layer PCB manufacturing involves using woven glass cloth and epoxy resin. The epoxy resins are then cured, forming the core of the board. Afterwards, the core and copper sheeting are bonded together by heat and pressure. This results in a multi-layer PCB with uniform properties.

Another manufacturing process is panelization, which is the process of combining multiple small printed circuit boards onto a single panel. This technique combines several different designs onto one large board. Each panel consists of an outer tooling strip that has tooling holes, panel fiducials, and a test coupon. Some panels also include a hatched copper pour to help prevent bending during the paneling process. Panelization is common when components are mounted close to the edge of a board.

Class 2 and 3 PCBs

While most manufacturers of Class 2 and Class 3 printed circuit boards adhere to the same standards, there are a few key differences between these two classes. Class 2 boards are typically manufactured for products that are not exposed to extreme environmental conditions, are not critical to the end user, and are not subject to rigorous testing. Class 3 boards, on the other hand, are designed to meet the highest standards and must provide continuous performance and minimal downtime. The main difference between the two classes is the requirements for board design and manufacturing process.

Class 2 and 3 printed circuit boards are made to IPC-6011 standards. These standards describe the requirements for Class 1, Class 2, and Class 3 printed circuit boards. There are also newer IPC standards called Class 3/A. These are designed for military avionics and space applications. Class 1 and Class 2 PCBs must meet the IPC’s Rigid, Flex, and MCM-L standards.

Single-sided PCBs

Single-sided printed circuit boards (PCBs) are a common and relatively easy to design circuit board. As a result, most manufacturers and designers can design and build these boards. Single-sided PCBs are also easier to produce than multi-layered PCBs. As a result, almost any PCB manufacturing company can produce them. Single-sided PCBs are most commonly ordered in high quantities.

Single-sided PCBs are typically made of FR4 material, a fiberglass-like substance mixed with epoxy. The material is formed into multiple layers, with each layer containing one layer of conductive material. Leads are then soldered to copper tracks on the component side. Single-sided PCBs were originally used to fabricate prototype circuit boards, but as the demand for surface-mount components grew, they were replaced by multi-layer PCBs.

Single-sided PCBs are the simplest and cheapest form of printed circuit boards. They feature a single layer of conductive copper above the substrate. In addition, there are no via holes in single-sided PCBs. As such, they are most suited for low-density designs. They are easy to manufacture and are often available in short lead times.

Flex PCBs

There are several steps that take place in the production of flex PCBs. The first step involves designing the layout of the board. This can be done using CAD tools such as Proteus, Eagle, or OrCAD. After the layout has been designed, the assembly process can begin.

The next step involves routing the conductors. The width of the conductors should be set at a standard for the device. However, the number of conductors may vary depending on the design. The standard conductor width is necessary for a circuit that requires a certain percentage of circuit current. Depending on the design, the diameters of holes can also vary.

After the template has been etched, the flex circuit is cut using a process called “blanking”. A hydraulic punch and die set is used for this process, but its tooling costs can be high. Another option is using a blanking knife. A blanking knife is a long razor blade that is bent into the shape of the flex circuit outline. It is then inserted into a slot in a backing board, usually MDF or plywood.