Whats the Difference Between SMD and NSMD?

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Whats the Difference Between SMD and NSMD?

SMD and NSMD are two types of semiconductors. While their pads are similar in size, NSMD components have smaller dimensions. In contrast, SMDs can be moved by the soldering iron, while a through-hole component can be mechanically secured prior to soldering.

NSMD pads are smaller

There are several differences between NSMD pads and SMD pads. Firstly, the solder mask for NSMD pads is made much smaller. This allows for the pad edge to leave a small gap that is not present on SMD pads. The following figure shows a top and cross-section view of an NSMD-style pad.

NSMD pads are smaller than SMD pads and are therefore more suitable for high density board layouts. They also allow more space between adjacent pads and allow easier trace routing. As a result, NSMD pads are used in high-density BGA chips. However, NSMD pads are more susceptible to delamination, but standard manufacturing practices should prevent this problem.

In addition to being smaller, NSMD pads are cheaper to manufacture. This is due to the fact that they are made of less expensive materials. However, this does not mean that they are of inferior quality. Whether you choose NSMD or SMD will depend on your application. For example, a board with large pads will need a solder mask that has a larger solder mask aperture than one with small pads.

When it comes to manufacturing BGA components, proper pad design is crucial. NSMD pads are smaller because they have solder mask apertures that are smaller than the copper pad diameter. NSMD pads also have a risk of asymmetrical solder bump, which will tilt the device on the PCB.

NSMD pads are used for diodes

NSMD pads are a kind of diode-packaging pads that differ from SMD pads in one important way: a gap is left between the pad edge and solder mask. Using a NSMD-style pad can result in improved solder connections and package pads with wider trace widths.

The solder lands on a PCB are either solder-mask defined or non-solder mask defined. The non-solder-mask defined pad is characterized by a gap between the solder mask and the circular contact pad. Solder flows over the top and sides of the contact pad to create a high-quality solder joint.

The diameter of an NSMD pad is often smaller than the diameter of a BGA pad. This reduced size allows easier trace routing. However, NSMD pads can be more prone to delamination than SMD pads. As a result, it is necessary to adhere to standard manufacturing practices to minimize the possibility of pad delamination.

When soldering BGA components, the pad design plays a crucial role. A bad pad can lead to poor manufacturability and costly hours of failure analysis. Fortunately, there are simple guidelines for pad design. With a little practice, you can make the correct NSMD pads for your BGA components.

NSMD pads are used for transistors

When using NSMD pads for transistors, you must remember that a NSMD pad is smaller than a corresponding SMD pad. This difference is due to the fact that the NSMD pads have a larger opening for the solder mask to fit. This allows for greater surface area for solder joints, a wider trace width, and increased flexibility in through-holes. However, this difference also means that an NSMD pad is more likely to fall off during the soldering process.

The diameter of a copper pad is a key factor in defining the size of an NSMD pad. NSMD pads are approximately 20% smaller than a solder ball, allowing for better trace routing. This reduction is necessary for high-density BGA chips. However, a NSMD pad is more prone to delamination, but standard manufacturing practices should minimize this problem.

NSMD pads are a good option when soldering transistors. These types of pads are often used in applications where transistors must be soldered through a hole in a metal substrate. This makes the soldering process easier and less time-consuming. However, the downside of using a NSMD pad is that you can’t get the same level of control over the soldering process as with a SMD pad.

The other major advantage of using SMD pads is that they can be easily manufactured. This method is very popular for manufacturing electronic components, as it is the most cost-effective way to create a high-quality board. Furthermore, the SMD approach is also a good way to minimize the number of variables that are involved in your design.

Cacat PCB Paling Umum dan Solusinya

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Cacat PCB Paling Umum dan Solusinya

There are many problems with PCBs, but some of them are less obvious than others. These problems are called implementation failures and require specialized knowledge to diagnose. For example, Electrostatic discharge, Chemical leakage, Lifted pads, and component shifting are all possible causes of failure. To identify the failure modes, a PCB must be stress tested until it fails.

Electrostatic discharge

Electrostatic discharge (ESD) is a common problem in electronic circuits. It results from the wrong handling of electronic components or an excessive voltage level. In many cases, the resulting damage is latent or catastrophic. This problem can cause a PCB to malfunction partially or completely.

There are several ways to detect and repair electrostatic discharge. While some of these are visible and will affect the performance of the product, others will not. The first method is to inspect the device to determine if any component is affected. In some cases, a minuscule hole will appear on the circuit board.

Kebocoran bahan kimia

Chemical leakage in PCBs can be a problem for many industries. Although the United States banned the production of PCBs in 1977, they are still found in the environment at very low levels. Environmental cycling is the primary source of ambient PCBs, and they are transported throughout ecosystems. Although these contaminants have low levels, they can have serious effects on humans and the environment.

In addition to their use in electronics, PCBs were also used in the construction of school buildings during the 1950s to 1970s. Many schools had PCB-containing caulk and fluorescent light fixtures. The problem with these products was that they leaked, causing contamination in other building materials and the soil. This caused widespread contamination, which is why they were banned.

Lifted pads

Lifted pads are caused by a number of causes, including excess heat and force during soldering. The result can be an unsatisfactory solder joint. These defects require re-soldering, and can lead to short circuit hazards. Other causes of lifted pads include pollutant contamination, poor cleaning, or insufficient flux. Lifted pads can affect the functioning of circuits and the appearance of the board.

Lifted pads occur most frequently on thin copper layers and boards that lack through-plating. Identifying the root cause of a lift is crucial for preventing further damage. In the case of single-sided circuit boards, the problem is often the result of improper wave soldering. The lift can be prevented by using extreme caution while handling PCBs and avoiding excessive force when handling components.

Component shifting

Component shifting is one of the most common defects encountered in PCB assembly. It can be caused by a number of factors, including the placement of components incorrectly. For example, a component placed in a way that is not oriented correctly may float, resulting in a realignment of the component.

In some cases, the cause of component shifting is due to mismatching of the parts to the pad geometry. This causes the component to move towards the thermal mass closest to it. Other causes include bent leads, improperly placed components, or oxidation. Fortunately, there are a number of solutions to component shifting. For instance, adhering to the correct reflow profile, reducing movement during the unreflowed assembly process, and using an aggressive flux can all help minimize component movement.

Soldering ball defects

Soldering ball defects are common in the SMT assembly process. They are essentially balls of solder that separate from the main body of the solder. To prevent them, you should adjust the mounting pressure on the chip mounter to a precise setting. This will prevent the solder paste from being squeezed out of the pad and increase the chance that the solder paste will be generated properly.

A good solder joint will be clean, symmetrical, and have a concave shape. On the other hand, a bad solder joint may be large and have a long stem. Another common defect is disturbed joints, which will have a flaky, distorted, or uneven appearance.

Thermal imaging

Thermal imaging is a powerful tool for quality control, speeding up PCB and component repairs. By identifying hot spots, thermal images can point out faulty components or areas that are using too much power. This information can help designers reduce power consumption and prolong battery life. Thermal imaging can also detect areas that have poor thermal management, requiring more cooling, larger heat sinks, or even redesign.

Thermal imaging for PCB defects can also help designers and engineers determine the cause of defects. When a test board fails to pass quality control tests, a thermal imager can reveal the problems. It can also show the differences in temperature between two different areas of a board, revealing how the two differ.

5 Faktor yang Mempengaruhi Kualitas Penyolderan SMT

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5 Faktor yang Mempengaruhi Kualitas Penyolderan SMT

Beberapa faktor memengaruhi kualitas penyolderan SMT. Ini termasuk kondisi peralatan, kualitas pasta solder, dan Stabilitas. Memahami faktor-faktor ini akan membantu Anda meningkatkan proses penyolderan SMT. Cara terbaik untuk meningkatkan kualitas penyolderan SMT adalah dengan mengimplementasikan perbaikan di setiap area.

Stabilitas

Dalam proses manufaktur di mana komponen ditempatkan pada PCB, stabilitas sambungan solder penting untuk performa sirkuit. Namun, dalam kondisi tertentu, proses penyolderan bisa tidak stabil. Dalam kondisi ini, pasta solder SnAgCu bebas timbal digunakan untuk mengurangi tekanan termal pada substrat. Pasta solder jenis ini memiliki keunggulan dibandingkan bahan lainnya: dapat digunakan pada berbagai substrat dan dapat diaplikasikan dengan mengeluarkan pasta ke permukaan perangkat.

Pasta solder yang baik akan stabil pada suhu tertentu. Cara terbaik untuk memeriksa stabilitas pasta solder Anda adalah dengan menggunakan viskometer untuk mengukur viskositasnya. Pasta yang baik harus berada di antara 160 Pa*S dan 200 Pa*S.

Pengulangan

Selama proses penyolderan, fluks adalah bahan utama untuk keberhasilan proses penyolderan. Jika fluks tidak mencukupi atau ada terlalu banyak kotoran, proses penyolderan bisa gagal. Cara terbaik untuk memastikan pengulangan penyolderan SMTS adalah dengan menyiapkan komponen dan bantalan PCB secara hati-hati sebelum menyolder. Penting juga untuk menjaga suhu reflow dengan benar dan menghindari pergerakan rakitan selama reflow. Terakhir, paduan harus dianalisis untuk mengetahui adanya kontaminan.

Meskipun solder bebas timbal direkomendasikan, solder bertimbal dapat digunakan dalam kasus-kasus tertentu. Namun, penting untuk diperhatikan bahwa solder bertimbal tidak memiliki fluks yang diperlukan untuk membuat sambungan yang andal. Akibatnya, proses penyolderan tidak dapat diulang.

Status peralatan

Banyak faktor yang memengaruhi kualitas penyolderan SMT. Faktor-faktor ini termasuk desain bantalan PCB, kualitas pasta solder, dan kondisi peralatan yang digunakan untuk pembuatan. Masing-masing faktor ini sangat penting untuk asuransi kualitas penyolderan reflow. Selain itu, mereka juga dapat memengaruhi cacat penyolderan. Untuk meningkatkan kualitas penyolderan, sangat penting untuk menggunakan desain pad PCB yang sangat baik.

Selain pemilihan komponen, presisi pemasangan adalah faktor lain yang memengaruhi kualitas sambungan solder. Peralatan yang digunakan untuk pemasangan harus memiliki presisi tinggi agar komponen tetap stabil. Selain itu, sudut pemasangan harus benar untuk memastikan bahwa perangkat kutub diorientasikan dengan benar. Selain itu, ketebalan komponen setelah pemasangan harus sesuai.

Kualitas pasta solder

Cacat penyolderan dapat disebabkan oleh berbagai faktor. Sering kali, masalah ini disebabkan oleh desain PCB yang tidak tepat. Desain pad yang salah dapat menyebabkan komponen bergeser atau berbentuk batu nisan, serta cacat penyolderan. Untuk alasan ini, desain bantalan PCB harus diteliti dengan cermat untuk menghindari masalah ini.

Suhu dan kelembapan memainkan peran penting dalam kualitas pasta solder. Suhu yang ideal untuk aplikasi adalah sekitar 20 derajat Celcius dan kelembapan yang tepat adalah antara tiga puluh hingga lima puluh persen. Tingkat kelembapan yang tinggi dapat menyebabkan terbentuknya bola-bola, yang mempengaruhi proses penyolderan. Kecepatan dan kualitas pisau pengikis juga merupakan faktor penting yang mempengaruhi penyolderan. Untuk hasil yang optimal, pasta solder harus diaplikasikan mulai dari bagian inti dan bergerak ke arah tepi papan.

Kecepatan, tekanan pengikis, kecepatan penurunan stensil, dan mode pembersihan stensil harus dioptimalkan untuk pencetakan pasta solder yang maksimal. Kecepatan yang tidak tepat dapat menghasilkan pencetakan pasta solder yang tidak merata dan dapat mengurangi efisiensi produksi. Parameter penting lainnya adalah frekuensi pembersihan stensil. Kecepatan pembersihan stensil yang terlalu tinggi atau terlalu rendah dapat menyebabkan penumpukan timah, yang dapat memengaruhi efisiensi produksi.

Desain PCB

Desain PCB adalah aspek penting dari kualitas produksi. Hal ini melibatkan pemosisian komponen yang tepat pada papan untuk memastikan bahwa komponen tersebut dipasang dengan benar. Ini harus mencakup jarak yang cukup untuk lubang pemasangan mekanis. Jika tidak, komponen yang sensitif dapat rusak. Selain itu, sambungan solder di dekat jejak kaki komponen yang dipasang di permukaan dapat menyebabkan short. Oleh karena itu, sangat penting bahwa desain PCB memungkinkan penempatan yang tepat untuk komponen pemasangan konvensional dan permukaan.

Selain penempatan komponen yang benar, desain PCB yang tepat juga dapat berkontribusi pada penyolderan SMT. Menurut statistik HP, sekitar 70 hingga 80 persen kesalahan produksi disebabkan oleh cacat pada desain PCB. Faktor-faktor yang memengaruhi desain PCB meliputi tata letak komponen, desain bantalan termal, jenis paket komponen, dan metode perakitan. Desain PCB juga harus mempertimbangkan titik-titik kompatibilitas elektromagnetik (EMC) dan posisi via.

How High Thermal Conductivity PCB Material Will Solve the Heat Dissipation Problem

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How High Thermal Conductivity PCB Material Will Solve the Heat Dissipation Problem

PCBs, also known as printed circuit boards, are layered structures made of copper foils sandwiched between glass-epoxy layers. These layers serve as a mechanical and electrical support for components. The high-conductivity copper foils serve as the conductive circuit in the PCB, while the glass-epoxy layer serves as the non-conductive substrate.

High thermal conductivity pcb material

Thermal conductivity is the ability of a material to transfer heat away from a device. The lower the thermal conductivity, the less efficient the device is. High thermal conductivity materials can eliminate the need for vias and produce a more uniform temperature distribution. This also reduces the risk of localized volumetric expansion, which can lead to hotspots near high-current components.

A typical PCB for a personal computer might consist of two copper planes and two outer trace layers. Its thickness is about 70 um and its thermal conductivity is 17.4 W/mK. The result is that the typical PCB is not an efficient heat conductor.

Copper coins

Copper coins are small pieces of copper embedded into the PCB. They are placed under the component that produces the most heat. Their high thermal conductivity allows them to transfer heat away from the hot component to a heat sink. They can be made in different shapes and sizes to fit the desired areas and can be metalized to ensure a tight connection.

Glass-epoxy

The problem of heat dissipation is becoming more important in electronics. Excess heat can lead to underperformance and early failure. Currently, heat dissipation options are limited, particularly in the extreme environments. One of the solutions to this problem is the use of high-temperature glass epoxy PCB material, or HDI-PCB. This material is able to solve this problem by having a thermal conductivity over two hundred times better than FR4 composite.

The glass epoxy resin has excellent heat and flame resistance. It has a high glass transition temperature and high thermal conductivity. It can serve as an insulating layer and a heat dissipation layer. It can be made by impregnation or coating. The thermal conductivity of glass epoxy PCB will improve the performance and stability of electronic components.

Metal core PCBs

Metal core PCB manufacturers have introduced new board substrates that can withstand high temperatures. This allows them to selectively apply thicker copper layers that have higher thermal conductivity. This type of PCB enables better heat dissipation and can be used for fine circuit patterns and high-density chip packaging.

In addition to offering higher thermal conductivity, metal PCBs are also dimensionally stable. Aluminum metal core PCBs have a 2.5-3% size change when heated, making them ideal for high-power applications. Their low thermal expansion properties also make them suitable for high switching power. The most commonly used metal used for a metal core PCB is aluminum, which is cheap and recyclable. Its high thermal conductivity allows for a fast cooling process.

Another problem associated with heat dissipation is the risk of excessive heat. The heat generated by heat-generating components must be removed from the board, otherwise the PCB will not perform at its best. Fortunately, there are now new options to solve this problem. High thermal conductivity metal core PCBs are a new kind of thermal solution that can overcome these problems.

FR4 substrates

PCBs are layered structures made of copper foils and glass-reinforced polymers. They support and connect electronic components. The copper creates a conductive circuit within the PCB, while the glass-epoxy layer acts as a nonconductive substrate.

High-power components are best placed near the center of the PCB, rather than on the edges. This is because heat accumulates near the edges and scatters out. Also, heat from high-power components should be placed far away from sensitive devices, and the heat must be channeled away through the PCB.

High thermal conductivity PCB material is the best solution for heat dissipation, allowing for rapid transfer of heat and preventing heat accumulation. High-tech PCBs use copper base, aluminum, or ceramic as the substrate material. This will solve the heat dissipation issues and make the PCBs more durable.