PCB 레이어 스택업을 사용하여 전자파 방사를 제어하는 방법

PCB 적층 스택업은 EMC를 줄이고 EMF 방출을 제어하는 가장 좋은 방법 중 하나입니다. 하지만 위험이 없는 것은 아닙니다. 두 개의 신호 레이어로 PCB를 설계하면 신호 라우팅을 위한 보드 공간이 부족하여 PWR 평면이 절단될 수 있습니다. 따라서 두 개의 적층된 전도성 평면 사이에 신호 레이어를 배치하는 것이 좋습니다.

Using a 6-layer PCB stackup

A 6-layer PCB stackup is effective for decoupling high-speed signals and low-speed signals, and can also be used to improve power integrity. By placing a signal layer between the surface and the interior conductive layers, it can effectively suppress EMI.

The placement of the power supply and ground on the 2nd and fifth layers of the PCB stackup is a critical factor in controlling EMI radiation. This placement is advantageous because the power supply’s copper resistance is high, which can affect the control of common-mode EMI.

There are different configurations of 6-layer PCB stackups that are useful for different applications. A 6-layer PCB stackup should be designed for the appropriate application specifications. Then, it must be thoroughly tested to ensure its functionality. After this, the design will be turned into a blue print, which will guide the manufacturing process.

PCBs used to be single-layer boards with no vias and clock speeds in the hundred kHz range. These days, they can contain up to 50 layers, with components nestled between layers and on both sides. Signal speeds have increased to over 28 Gb/S. The benefits of solid-layer stackup are numerous. They can reduce radiation, improve crosstalk, and minimize impedance issues.

Using a core-laminated board

Using a core-laminated PCB is an excellent way to protect electronics from EMI radiation. This type of radiation is caused by fast-changing currents. These currents form loops and radiate noise when they change rapidly. In order to control the radiation, you should use a core-laminated board that has a low dielectric constant.

EMI is caused by a variety of sources. The most common is broadband EMI, which occurs over radio frequencies. It is produced by a number of sources, including circuits, power lines, and lamps. It can damage industrial equipment and reduce productivity.

A core-laminated board can include EMI reducing circuits. Each EMI reducing circuit comprises a resistor and a capacitor. It can also include a switching device. The control circuit unit controls each EMI reducing circuit by sending selection and control signals to the EMI-reducing circuits.

Impedance mismatching

PCB layered stackups are a great way to improve EMI control. They can help contain electrical and magnetic fields while minimizing common-mode EMI. The best stackup has solid power and ground planes on outer layers. Connecting components to these planes is faster and easier than routing power trees. But the trade-off is increased complexity and manufacturing costs. Multilayer PCBs are expensive, but the benefits may outweigh the trade-off. To get the best results, work with an experienced PCB supplier.

Designing a PCB layered stackup is an integral part of the signal integrity process. This process requires careful consideration of mechanical and electrical performance requirements. A PCB designer works closely with the fabricator to create the best possible PCB. Ultimately, the PCB layer stackup should be able to route all signals successfully, keep signal integrity rules intact, and provide adequate power and ground layers.

A PCB layered stack-up can help reduce EMI radiation and improve signal quality. It can also provide a decoupling power bus. While there is no one solution to all EMI issues, there are several good options for optimizing PCB layered stacks.

Trace separation

One of the best ways to control EMI radiation is to use layer stack up in PCB designs. This technique involves placing the ground plane and signal layers next to each other. This allows them to act as shields to the inner signal layers, which helps reduce common-mode radiation. Moreover, a layered stackup is much more efficient than a single-plane PCB when it comes to thermal management.

In addition to being effective in containing EMI radiation, a PCB layered stack design also helps improve component density. This is done by ensuring that the space around the components is larger. This can also reduce common-mode EMI.

To reduce EMI radiation, a PCB design should have four or more layers. A four-layer board will produce 15 dB less radiation than a two-layer board. It is important to place the signal layer close to the power plane. The use of good software for PCB design can aid in choosing the right materials and performing impedance calculations.

SMD 대 THT 대 SMT

When deciding which type of PCB to use, it’s important to understand the differences between SMD and THT. Each type has advantages and disadvantages. SMT requires advanced equipment and a custom stencil, while THT uses hand soldering to attach components. Because of these differences, SMT is generally the better choice for large-scale production and for high-speed applications. In contrast, THT is more appropriate for smaller projects and prototypes.

smd vs tht vs smt

In electronics, surface mount technology refers to the process of mounting electronic components directly onto a PCB. Its advantages include the ability to produce smaller PCBs. It replaces the traditional through-hole technology.

Typically, SM components are smaller than their through-hole counterparts and have contact terminals on the end of the component’s body. Many components are available in SMD packages, including capacitors, inductors, and resistors.

Surface mount devices are generally less expensive than their through-hole counterparts, but they require more sophisticated production technology and design. The increased capital investment is offset by higher throughput with a fully automated setup. The faster production time helps make them the better choice for many manufacturers.

The main differences between SMT and TH components are mechanical stability and fine-pitch requirements. In addition to being cheaper, SMT components are easier to assemble in large quantities, especially for smaller parts. Using Pick and Place machines and a Reflow Oven, SMT components are assembled at high speeds. However, SMT components require more training and expensive equipment to solder them properly.

THT requires more drilling than SMT, but it provides stronger mechanical bonds. It is suitable for high-reliability applications, where components are exposed to greater stress. However, the extra drilling is a drawback and increases the cost of the circuit board.

While SMT requires less drilling of the PCB, through-hole assembly can be much more expensive. However, it can be more efficient. In addition, SMT can produce smaller PCBs with fewer drill holes, which will save you money. In addition, SMT uses automated machines to place the components, which makes it cheaper than THT.

Surface mount technology is a budget-friendly alternative to through-hole technology, which requires highly skilled operators and expensive equipment. In addition to cost savings, surface mount components are more reliable than through-hole components. Surface mount technology also allows for higher component density per unit area.

However, SMT components are often smaller than through-hole components. Because of their size, they often require magnification to read their markings. This makes them less desirable for prototyping, rework, and repair, but it is possible to repair these components with a soldering iron. But this requires considerable skill and is not always feasible.

Surface mount devices come in many shapes and materials. They are classified into different categories. Some are passive, like capacitors and resistors. Others are active, such as diodes. A mixed device may combine both types of devices, such as an integrated circuit.

Surface mount technology is becoming the mainstay of the PCB industry, but it is important to keep in mind that through-hole technology may be better for certain applications. It is more reliable than surface mount technology, and it is used for many applications in the military. It is also easier to test, prototype, and replace components. A breadboard with through-hole components is ideal for prototyping.

PCB 인터커넥트 설계에서 RF 효과를 최소화하는 방법

There are a number of different ways to minimize the RF effect in a PCB interconnect design. Some of these include ensuring that the traces are not in close proximity to one another, using a ground grid, and separating RF transmission lines from other traces.

Multilayer configuration

RF effect in PCB interconnect design is a common problem. This effect occurs mainly because of nonideal circuit properties. For example, if an IC is placed on two different circuit boards, its operating range, harmonic emissions, and interference susceptibility will be drastically different.

To minimize this effect, a multilayer configuration is necessary. Such a board should have a reasonable layout, high-frequency impedance, and simple low-frequency wiring. Using the correct substrate material minimizes signal loss, and it helps maintain consistent impedance throughout the circuits. This is crucial because signals transition from the circuit to the transmission lines, and they must have constant impedance.

Impedance is another issue with PCB interconnect design. It is the relative impedance of two transmission lines, beginning at the PCB surface and extending to the connector or coaxial cable. The higher the frequency, the more difficult it is to manage the impedance. Therefore, the use of higher frequencies seems to be a significant design challenge.

Creating a ground grid

One way to reduce the rf effect is to create a ground grid on your PCB. A ground grid is a series of box sections that is connected by traces to ground. Its purpose is to minimize the signal return path, while still maintaining low impedance. The ground grid can be either a single trace or a network of overlapping traces.

The ground plane acts as a reference to calculate the impedance of signal traces. In an ideal system, the return current stays on the same plane as the signal traces. However, in real systems, the return current may deviate from the ideal path due to various factors, including variations in the copper plating of the PCB and the laminate material used.

Separating RF transmission lines from other traces

When designing circuits with multiple traces, it is important to separate RF transmission lines from the rest of the circuit. Separation of these traces is important in order to prevent crosstalk. To achieve this, it is best to space RF transmission lines at least two trace widths apart. This distance reduces the amount of radiated emissions and minimizes the risk of capacitive coupling.

RF transmission lines are typically separated from other traces by striplines. In multi-layer printed circuit boards, striplines are most easily constructed on the inner layers. Like microstrip, striplines have ground planes above and below the RF transmission line. While striplines offer better isolation than microstrip, they tend to have a higher RF loss. For this reason, striplines are typically used for high-level RF signals.

Using PTFE ceramics

RF effect is a very real concern in PCB interconnect design. Due to high frequencies, the signals traveling on a trace can shift. This causes the dielectric constant to change depending on the speed of the signal and the tracing geometry. The dielectric constant of the PCB substrate material also affects the speed of the signal.

When comparing ceramics to solder, PTFE ceramics have an edge over FEP ceramics. While the former is cheaper and easier to fabricate, it will reduce signal reliability. Besides, PTFE ceramics are less likely to absorb moisture. However, if the PTFE ceramics are covered by hydrocarbons, the moisture absorption will increase.

Using symmetric stripline routing

Stripline routing is a common approach in digital circuit design. It uses a dielectric layer sandwiched between two ground planes with signal-carrying conductors in the center. This method is called symmetric stripline. Typical stripline dimensions are s=2.0, w=3.0, t=1.0, and b=5.0.

This method has two major advantages over microstrip. It allows for smaller traces, which provide more protection against aggressor signals. In addition, stripline routing can help minimize RF impact on the interconnect design. However, it requires careful consideration of the board layer stackup and the dielectric materials between ground planes.

As for the PCB track width, it should not exceed two inches. This is important for high-speed logic, which has a rise/fall time of five nanoseconds. It is advisable to terminate high-speed logic PCB tracks with a characteristic impedance, and to avoid voids in the reference plane.

PCB 실크스크린을 우아하게 배열하는 방법

There are a few things to consider when using PCB silkscreen. First, you have to decide how to arrange your silkscreen characters. This is very important because you will want to make sure they are not placed beneath a component or over a via pad. It is also important to make sure that the characters are not too big.

Using copper pads

PCB layout is a challenging process that requires careful planning. To achieve the desired result, it’s important to use the right tools and techniques. One way to do this is to use PROTEL AUTOTRAX under DOS, which enables you to edit strings and layouts. However, it is important to be aware that you may need to manually adjust pad sizes for two-legged chip components and four-row patch ICs.

Before you start creating a silkscreen, be sure to check with your CM for the recommended layout. Often, the CM will tell you to keep the silkscreen to only one side of the PCB.

Using reference designators

When designing a printed circuit board, using reference designators is a useful way to clearly identify components on the board. They usually start with a letter followed by a numeric value. Each reference designator will represent a particular class of component. Reference designators should be placed above the component so that they are clearly visible once it has been mounted on the PCB. Reference designators are usually painted with yellow or white epoxy ink or silkscreen.

The placement of reference designators is crucial. When placing a component on a PCB, ensure that it is placed as close as possible to its associated component. Similarly, if a component is placed vertically, it should have its reference designator on the bottom-left edge of the board. The placement of reference designators can reduce assembly errors. However, placing them beneath component symbols can make them difficult to read once mounted. Moreover, it is advisable not to place them on high-speed signal traces.

Using automatic alignment

PCBAs contain a variety of silkscreen markings and information. These include regulatory markings such as RoHS, FCC, and CE, as well as E-waste disposal markings. Additionally, there are PCBs with UL markings, which means the board has been fabricated by a UL-certified manufacturer.

These layers are then fused together using a process known as layer-up and bonding. The outer layer material consists of fiber glass or other material that has been pre-impregnated with epoxy resin, or prepreg. It also covers the original substrate and copper trace etchings. The layers are then assembled on a heavy steel table. The pins fit tightly into each other to prevent the layers from shifting.

The positioning of reference designators is very important. The designators should be close to the part they are meant to identify, and rotated appropriately to make them readable. It is also important that the part or component you are placing is not obscured by the silkscreen. This can make it difficult to read.

Manually specifying line widths

There are several reasons to manually specify line widths when arranging PCB silkscreened components. The first reason is that the line widths will have an impact on how your PCB silkscreen looks. If the line widths are too large or small, you may have trouble reading them. Additionally, too few lines may result in skips or blurry text. For this reason, it’s important to set a minimum line width of 0.15 mm (six mils). It is generally better to specify line widths of 0.18 mm to 20 mm.

There are other considerations as well, such as the size of the silkscreen fonts. If you are creating a silkscreen for a PCB, you should choose a font size of at least 0.05 inches for optimum readability. When placing reference designators, you should leave about 5 mils of space between each line. You should also ensure that they are oriented from left to right and bottom to top to avoid uneven silkscreening.

Using drafting features

PCB silkscreen is an important part of the finished circuit board and should be carefully crafted. To make sure your silkscreen looks its best, use the appropriate font sizes and line widths. Otherwise, you may end up with ink splots and a poor silkscreen layout.

One of the most common silkscreen errors is failing to mark polarized components clearly. For example, when drawing a PCB with electrolytic capacitors, always ensure that you mark the positive pin. For diodes, you should always use an “A” or “C” symbol to distinguish the anode from the cathode.

PCB 기판 납땜 결함 확인 방법

PCB 납땜 결함에는 몇 가지 일반적인 유형이 있습니다. 이러한 결함에는 핀 홀과 블로우 홀이 포함됩니다. 핀 홀은 납땜 조인트의 작은 구멍이고, 블로우 홀은 큰 구멍입니다. 이 두 가지 결함은 모두 부적절한 수작업 납땜으로 인해 발생합니다. 납땜 공정 중에 기판의 수분이 가열되어 가스로 변하고 용융된 땜납을 통해 빠져나갑니다. 이렇게 되면 보드에 빈 공간이 생기고 핀 구멍과 블로우 홀이 생깁니다.

일반적인 PCB 납땜 결함 유형

몇 가지 일반적인 유형의 PCB 납땜 결함은 부적절한 납땜 기술로 인해 발생할 수 있습니다. 이러한 문제에는 고르지 않은 가열과 고르지 않은 열 분포가 포함됩니다. 이로 인해 납땜이 고르지 않게 용융되어 부품 툼스톤이 발생할 수 있습니다. 적절한 솔더 페이스트를 사용하고 적절한 온도 범위에서 기판을 리플로우하면 이 문제를 방지할 수 있습니다.

납땜 공정의 결함은 아름다운 PCB 디자인을 망칠 수 있습니다. 이러한 결함은 설계자의 잘못인 경우가 드물고 제조상의 오류로 인한 것일 가능성이 높습니다. 제조업체는 검사 단계에서 이러한 문제를 발견하는 방법을 알고 있어야 합니다. 대부분의 경우 문제는 웨이브 솔더링 공정에 있습니다.

또 다른 일반적인 결함은 납땜 볼링으로, 작은 납땜 볼이 라미네이트 또는 도체 표면에 달라붙는 현상입니다. PCB 납땜 기술은 이러한 유형의 문제를 방지해야 합니다. 솔더 볼이 있는 PCB는 울퉁불퉁하고 칙칙해 보일 것입니다.

일반적인 원인

납땜 결함은 PCB 기판의 생산 과정에서 발생하는 일반적인 문제입니다. 이러한 결함으로 인해 단락, 오픈 조인트 또는 교차 신호 라인이 발생할 수 있습니다. 또한 납땜 온도와 습도의 변화로 인해 발생할 수도 있습니다. 또한 납땜을 잘못 도포하면 표면이 한쪽으로 치우치거나 납땜이 고르지 않을 수 있습니다.

PCB 고장의 가장 흔한 원인 중 하나는 열과 습도입니다. 재료마다 팽창과 수축 속도가 다르기 때문에 지속적인 열 스트레스는 납땜 접합부를 약화시키고 부품을 손상시킬 수 있습니다. 이러한 이유로 고성능 PCB는 열을 방출할 수 있어야 합니다.

불충분한 습윤은 납땜 조인트의 약화로 이어질 수 있습니다. 납땜은 깨끗한 표면에서 이루어져야 하며 납땜 인두의 온도가 적절해야 합니다. 그렇지 않으면 울퉁불퉁하고 접착력이 부족한 콜드 조인트가 발생할 수 있습니다.

일반적인 검사 방법

결함을 식별하고 전자 제품의 품질을 보장하는 데 사용되는 다양한 PCB 검사 방법이 있습니다. 이러한 방법에는 육안 검사 및 자동화된 테스트가 포함됩니다. 이러한 테스트는 PCB 조립 공정의 여러 단계에서 수행됩니다. 솔더 조인트 개방, 누락되거나 잘못된 구성 요소, 솔더 브리지 등 다양한 결함을 감지할 수 있습니다.

PCB 보드 납땜 결함을 식별하는 첫 번째 단계는 구성 요소를 식별하는 것입니다. 이를 위해서는 문자 뒤에 숫자를 붙인 참조 지정자를 지정해야 합니다. PCB의 각 구성 요소에는 고유한 참조 지정자가 있습니다. 예를 들어 저항은 R로 표시되고 커패시터는 C로 표시됩니다. 이러한 문자는 표준 문자와 다를 수 있지만 구성 요소를 식별하는 신뢰할 수 있는 방법입니다. 다음 단계는 검사 테스트 유형을 선택하는 것입니다. 이는 AOI, ICT 또는 기능 테스트를 사용하여 수행할 수 있습니다.

또 다른 일반적인 PCB 보드 검사 방법은 X-레이 검사입니다. 이 기술은 모든 각도에서 PCB를 검사할 수 있는 기계를 사용합니다. 현재 PCBA123은 2D X-레이 검사 시스템을 사용하고 있지만 조만간 3D AXI로 업그레이드할 계획입니다.

예방 조치

PCB 기판 납땜 결함은 여러 가지 문제로 인해 발생할 수 있습니다. 어떤 문제는 쉽게 식별할 수 있지만, 어떤 문제는 눈에 보이지 않을 수도 있습니다. PCB 보드에서 이러한 결함을 검사하는 가장 좋은 방법은 자동 육안 검사 시스템을 사용하는 것입니다. 예를 들어 자동 검사 시스템은 납땜 접합부 및 커패시터 극성의 결함을 감지할 수 있습니다.

보드 납땜 결함의 가장 일반적인 원인 중 하나는 납땜이 완전히 젖지 않았기 때문입니다. 이는 납땜에 너무 적은 열을 가하거나 보드에 너무 오래 방치할 때 발생할 수 있습니다. 기판이 제대로 젖지 않으면 구조적인 문제가 발생할 수 있으며, 이는 PCB의 전반적인 성능에 영향을 미칩니다. 그러나 기판 습윤을 개선하기 위해 취할 수 있는 몇 가지 예방 조치가 있습니다.

PCB 기판 납땜 결함의 또 다른 원인은 부적절한 스텐실 설계입니다. 스텐실이 부적절하게 설계되면 솔더 볼이 완전히 형성되지 않을 수 있습니다. 적절한 스텐실을 사용하면 솔더 볼 결함을 방지하고 회로 성능을 보장할 수 있습니다.