SMD Vs THT Vs SMT

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SMD Vs THT Vs 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.

6 Basic Rules of PCB Layout

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6 Basic Rules of PCB Layout

PCB layout involves designing a circuit with multiple layers. Some of the fundamental rules of PCB design are as follows: Avoid multiple ground planes. Make analog circuit signals direct and short. Avoid using three distinct capacitors on a single PCB. You can also read our articles on multi-layer PCB design and how to design a multi-layer PCB.

Designing a multi-layer PCB

When you are designing a multi-layer PCB, there are a few important things that you should consider. One of these is that the copper traces should maintain signal and power integrity. If they are not, then they could affect the quality of current. This is why it is necessary to use controlled impedance traces. These traces should be thicker than normal to prevent overheating.

Once you are clear on what you want, you can start designing the PCB. The first step in designing a multilayer PCB is to create a schematic. It will serve as the basis for your entire design. Start by opening a schematic editor window. You can then add and rotate details as needed. Make sure that the schematic is accurate.

Creating a single ground plane

Creating a single ground plane on a PCB layout helps reduce the amount of nonuniform voltages across a circuit board. This is accomplished by creating vias or through holes to connect the ground plane with other parts of the board. It also helps reduce noise produced by variations in return current.

While defining a ground plane on a PCB, it is crucial to ensure that the ground plane is not covered with conductive rings because this can lead to electromagnetic interference or even ground loops. Ideally, the ground plane should be located under electronic components. It may be necessary to rearrange the placement of some traces and components to fit the ground plane.

Keeping analog circuit signals direct and short

When implementing a PCB layout for analog circuits, it is important to keep the analog signal traces short and direct. In addition, analog components must be located near each other, which will simplify direct routing. Keeping noisy analog components close to the center of the board will also help reduce noise.

In addition to keeping analog circuit signals direct and short, designers should also avoid obstructing the return paths. Plane splits, vias, slots, and cutouts can cause noise as the analog signal seeks the shortest path back to its origin. As a result, the signal can wander near the ground plane, generating significant noise.

Avoiding three distinct capacitors

When designing a PCB layout, it is best to avoid placing three distinct capacitors on power pins. This arrangement may lead to more problems than it solves. One way to avoid three distinct capacitors is to use traces and coffer fill. Then, place them as close to the device’s pin as possible.

This is not always possible, however, since the distance between traces is not always what was calculated during the design phase. This is a common problem that can lead to problems during the assembly process. When considering placement, remember that the placement of each component is crucial to its functionality.

Using power layer copper

Using power layer copper in PCB layout requires proper planning. In this part of the board, you must allocate a specific area of the board for power network. You can also use inner layer division to allocate this area. To add this layer, you should use the command “PLACE-SPLIT PLANE” and then select the network to be allocated for split. Once you have the power layer area allocated, you can then use the copper paving technique to place the copper in the split area.

In addition to achieving even copper coverage, you must make sure that the thickness of the board is compatible with its core. Using the power plane symmetry alone will not guarantee a perfect copper coverage, as the copper in this part will tear when contour routing. Copper up to the board edge also will not be compatible with scoring (V-cut) techniques. To avoid this issue, it is recommended that you indicate the copper zone on the mechanical layer and that it has a minimum width of 0.5mm.

Using a list of guidelines to place components on a PCB

Using a list of guidelines to place a component on a PCB can help minimize the overall cost of developing a new product while shortening the product development cycle. These guidelines also help ensure a smooth transition from prototype to production. These guidelines are applicable to both analog and digital circuits.

Most board designers follow a set of guidelines when designing a PCB. For example, a typical board design rule is to minimize the length of digital clock traces. However, many designers do not fully understand the rationale behind these guidelines. Among other things, high-speed traces must not cross gaps in the signal return plane.

Cara Meminimalkan Efek RF dalam Desain Interkoneksi PCB

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Cara Meminimalkan Efek RF dalam Desain Interkoneksi PCB

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.

Degradasi EMI Setelah Mengisi Pompa Irigasi

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Degradasi EMI Setelah Mengisi Pompa Irigasi

Ada dua cara berbeda untuk menganalisis degradasi EMI setelah mengisi pompa irigasi: radiasi dan konduksi. Degradasi EMI setelah pengisian tergantung pada jenis bahan lem dan bagaimana proses pengardean input dilakukan. Degradasi EMI diperburuk oleh etanol dan air.

Degradasi EMI setelah pengisian

Degradasi EMI setelah mengisi catu daya sering disebut sebagai 'efek pengisian', yang menggambarkan hilangnya sensitivitas EMI setelah catu daya diisi. Degradasi ini merupakan kombinasi radiasi dan konduksi. 'Efek pengisian' terjadi karena bahan yang membentuk catu daya mengalami serangkaian perubahan. Beberapa perubahan ini mungkin tidak diinginkan, sementara yang lain dapat bermanfaat.

Energi elektromagnetik yang tidak diinginkan (EMI) adalah radiasi yang merambat ke ruang angkasa melalui penggabungan induktif dan kapasitif. Energi yang tidak diinginkan ini berbahaya bagi perangkat elektronik dan memengaruhi fungsinya. Radiasi ini bersifat non-konduksi, yang berarti bahwa sinyal tidak dihantarkan melalui logam atau bahan lainnya. Ketika sinyal menempuh jarak yang jauh, perambatannya dalam bentuk gelombang. Gelombang ini didominasi oleh medan radiasi pada jarak yang jauh, sedangkan medan induksi mendominasi pada jarak dekat permukaan. Sebaliknya, radiasi non-pengion tidak mengionisasi gas dan tidak mempengaruhi perangkat elektronik. Contoh radiasi non-pengion meliputi RF, oven microwave, inframerah, dan cahaya tampak.

Listrik statis adalah sumber EMI lainnya. Meskipun sulit untuk mengidentifikasi sumber kebisingan ini, namun dapat berasal dari sumber alami seperti petir. Selain mempengaruhi kinerja perangkat elektronik, EMI juga dapat menyebabkan masalah keamanan dalam banyak sistem. Penyebab paling umum dari EMI adalah pelepasan muatan listrik statis. Orang non-teknis mengenali jenis kebisingan ini sebagai radio statis, penerimaan televisi yang terdistorsi, dan bunyi klik pada sistem audio.

Degradasi EMI setelah diisi dengan air

Degradasi EMI setelah diisi dengan air setelah peralihan catu daya dapat diklasifikasikan ke dalam dua jenis: radiasi dan konduksi. Degradasi EMI setelah diisi dengan air biasanya disebabkan oleh perubahan suhu arde input dan bahan konduktif yang digunakan untuk membuat kapasitor berisi air. Bahan konduktif termasuk serat aluminium dan tembaga, yang memiliki konduktivitas listrik intrinsik tertinggi. Namun, permukaan serat ini rentan terhadap oksidasi, yang dapat memengaruhi konduktivitas komponen. Selain itu, beberapa pedagang yang tidak bermoral mungkin tidak menyediakan produk yang konsisten.

EMI dapat mempengaruhi keamanan dan kinerja peralatan listrik. Sinyal yang tidak diinginkan ini dapat mengganggu komunikasi radio dan menyebabkan kerusakan pada peralatan di dekatnya. Oleh karena itu, pelindung EMI merupakan persyaratan penting untuk perangkat elektronik. Berbagai metode dan bahan digunakan untuk pelindung EMI. Di bawah ini adalah beberapa di antaranya:

Komposit serat karbon kontinu menunjukkan EMI SE yang lebih baik dan lebih konduktif daripada komposit serat karbon terputus-putus. Komposit serat karbon kontinu dengan matriks karbon menunjukkan EMI SE sebesar 124 dB. Di sisi lain, serat karbon terputus-putus secara signifikan mengurangi SE komposit.

Catu daya switching telah meningkat dibandingkan regulator linier dalam hal efisiensi, tetapi masih menimbulkan arus terputus-putus yang dapat berdampak negatif pada keandalan sistem. Analisis EMI lebih mudah dilakukan untuk derau konduktif daripada derau yang terpancar. Derau konduktif dapat dievaluasi dengan menggunakan teknik analisis rangkaian standar.

Degradasi EMI setelah diisi dengan etanol

Interferensi elektromagnetik (EMI) dapat mempengaruhi komponen dan perangkat elektronik dalam banyak cara. Sebagai contoh, jika kapasitor mengalami puncak tegangan yang lebih tinggi dari tegangan nominalnya, kapasitor dapat mengalami degradasi dielektrik. Degenerasi ini dapat mengakibatkan kerusakan atau terbakar, tergantung pada karakteristik komponen.

Interferensi elektromagnetik adalah masalah umum dalam teknologi modern. Gangguan ini menyebabkan kegagalan fungsi perangkat elektronik dan dapat menyebabkan kerusakan pada sistem komunikasi. Interferensi ini disebabkan oleh berbagai sumber, termasuk percikan api dari sikat motor, sakelar sirkuit daya, beban induktif dan resistif, relai, dan pemutusan sirkuit. Bahkan jumlah EMI sekecil apa pun dapat menurunkan kinerja perangkat elektronik dan mengganggu keamanannya. Sumber EMI yang paling umum adalah pelepasan muatan listrik statis (ESD), yang dikenali banyak orang sebagai listrik statis di stasiun radio, penerimaan televisi yang terdistorsi, dan bunyi klik pada sistem audio.

EMI juga dapat dihasilkan dengan mengganti catu daya. Catu daya ini merupakan sumber EMI yang kuat dan memerlukan kontrol yang cermat. Sangat penting untuk mengukur kebisingan output dari catu daya ini untuk mengurangi risiko EMI. Ini adalah proses yang memakan waktu dan mahal.

Cara Mengatur Silkscreen PCB dengan Elegan

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Cara Mengatur Silkscreen PCB dengan Elegan

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.

Cara Menggunakan Beberapa Resistor untuk Meningkatkan Akurasi Multimeter

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Cara Menggunakan Beberapa Resistor untuk Meningkatkan Akurasi Multimeter

To improve the accuracy of your multimeter, you can use a few resistors and components. They should be held in place so that they stay in contact with the multimeter’s probes. Do not touch the resistors or components with your hands, as this will result in inaccurate readings. To avoid this problem, attach the components to a breadboard or use alligator clips to keep them in place.

Using shunt resistors

The resistance value of a shunt resistor is expressed in microOhms. The resistance of a shunt resistor is usually very small. Using this type of resistor improves the accuracy of the multimeter because it does not introduce undesired effects from lead resistance. It is important to use it with a Kelvin connection, however, because the resistance of shunt resistors tends to drift with the ambient temperature.

Multimeters are sensitive to load voltage, so operators must be vigilant about the burden voltage and resolution. Infrequent testing can result in unexpected product failures. Shunt resistors improve the accuracy of the multimeter by providing additional resolution. This is particularly useful for bench multimeters, which are capable of full-scale measurements.

Setting the correct range on an analog multimeter

To set the correct range on an analog multimeter, start by setting the ohms unit to its lowest value. In general, the resistance reading should be between 860 and 880 ohms. Alternatively, you can use the lower resistance range of 200 ohms for learning and practice.

A manual-ranging multimeter features a knob with many selection options. These are usually marked with metric prefixes. Auto-ranging multimeters, on the other hand, are automatically set to the appropriate range. In addition, they have a special “Logic” test function to measure digital circuits. For this function, you connect the red (+) lead to the anode and the black (-) lead to the cathode.

It may seem daunting to set the range on an analog multimeter, especially if you’ve never used one before. However, this task is surprisingly simple and can be done with a few resistors. As long as you’re aware of the different ranges, you’ll be more successful with this task.

Using precision current sensing resistors

The accuracy of a multimeter can be improved by using precision current sensing resistors. These components can be purchased in different styles. They are useful for applications where the correct amount of current entering and leaving a battery is necessary. They are also helpful for applications where temperature sensitivity is a concern.

The optimum footprint is C, with an expected measurement error of 1%. Recommended footprint dimensions are shown in Figure 6. The routing of the sensor trace also plays an important role in determining measurement accuracy. The highest accuracy is achieved when the sense voltage is measured at the resistor’s edge.

A current-sensing resistor is a low-value resistor that detects the flow of current and converts it to a voltage output. It is usually very low in resistance and therefore minimizes power loss and voltage drop. Its resistance value is usually on the milliohm scale. This type of resistor is similar to standard electrical resistors, but it is designed to measure the current in real time.

Touching the resistor or probe with your fingers

Multimeters also have a special feature that detects the positive and negative leads on a battery or power supply. Holding the multimeter probe against the lead for a few seconds will allow you to determine whether the current flowing through it is positive or negative. The red probe is connected to the positive battery terminal or wire.

When using a multimeter to measure resistance, you should make sure that the circuit is not powered on. Otherwise, you may receive an inaccurate reading. Remember that resistance is not as important as knowing how to measure it. Moreover, the current flowing in the circuit may damage the multimeter.

Testing continuity between holes on a breadboard

Before you measure resistance between holes on a breadboard, you should first check the breadboard’s connectivity. The test method is known as continuity check, and is a simple way to determine whether two connections are compatible. The breadboard has holes with a metal spring clip beneath each one. Connect the probes of your multimeter to both of these points. If you’re having trouble finding a conductive path between these points, attach a few resistors between the breadboard and the multimeter.

If you’re using a multimeter with a programmable feature, you can make it more accurate by testing continuity between a few holes at a time. To do this, insert the probes in the “+” and “-” columns of the breadboard and then measure the resistance across them. If the resistance is infinite, then the two rows are not connected.

Cara Memeriksa Cacat Penyolderan Papan PCB

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Cara Memeriksa Cacat Penyolderan Papan PCB

Ada beberapa jenis cacat penyolderan PCB yang umum terjadi. Cacat ini termasuk lubang pin dan lubang sembur. Lubang pin adalah lubang kecil pada sambungan solder, sedangkan lubang tiup adalah lubang yang lebih besar. Kedua cacat ini disebabkan oleh penyolderan tangan yang tidak tepat. Selama proses penyolderan, uap air di papan dipanaskan dan berubah menjadi gas, yang keluar melalui solder cair. Apabila hal ini terjadi, papan menjadi hampa, dan terbentuklah lubang pin dan lubang sembur.

Jenis cacat penyolderan PCB yang umum terjadi

Beberapa jenis cacat penyolderan PCB yang umum terjadi dapat dikaitkan dengan teknik penyolderan yang tidak tepat. Masalah ini termasuk pemanasan yang tidak merata dan distribusi panas yang tidak merata. Hal ini dapat mengakibatkan solder meleleh secara tidak merata dan dapat menyebabkan tombstoning komponen. Masalah ini dapat dihindari dengan menggunakan pasta solder yang tepat dan mengalirkan kembali papan dalam kisaran suhu yang tepat.

Cacat dalam proses penyolderan dapat merusak desain PCB yang indah. Cacat ini jarang terjadi karena kesalahan perancang, dan lebih sering disebabkan oleh kesalahan produksi. Produsen harus tahu bagaimana menemukan masalah ini selama fase inspeksi. Dalam banyak kasus, masalahnya terletak pada proses penyolderan gelombang.

Cacat umum lainnya adalah solder balling, yang menghasilkan bola-bola kecil solder yang menempel pada permukaan laminasi atau konduktor. Teknik penyolderan PCB harus menghindari jenis masalah ini. PCB yang memiliki bola solder akan terlihat menggumpal dan kusam.

Penyebab umum

Cacat penyolderan adalah masalah umum yang muncul selama proses produksi papan PCB. Cacat ini dapat menyebabkan korsleting, sambungan terbuka, atau jalur sinyal bersilangan. Cacat ini juga dapat disebabkan oleh variasi suhu dan kelembapan solder. Selain itu, solder yang tidak diaplikasikan dengan benar dapat menyebabkan permukaan yang miring dan penyolderan yang tidak rata.

Salah satu penyebab paling umum dari kegagalan PCB adalah panas dan kelembaban. Bahan yang berbeda mengembang dan menyusut dengan kecepatan yang berbeda, sehingga tekanan panas yang konstan dapat melemahkan sambungan solder dan merusak komponen. Untuk alasan ini, PCB berkinerja tinggi harus mampu membuang panas.

Pembasahan yang tidak memadai juga dapat menyebabkan sambungan solder yang lemah. Penyolderan harus dilakukan pada permukaan yang bersih, dan harus ada tingkat panas yang tepat untuk besi solder. Kegagalan untuk melakukannya dapat menyebabkan sambungan dingin, yang menggumpal dan tidak memiliki kemampuan ikatan.

Metode pemeriksaan umum

Ada berbagai metode pemeriksaan PCB, yang digunakan untuk mengidentifikasi cacat dan memastikan kualitas produk elektronik. Metode ini meliputi inspeksi visual dan pengujian otomatis. Pengujian ini dilakukan pada beberapa tahap proses perakitan PCB. Mereka dapat mendeteksi berbagai cacat, termasuk sambungan solder terbuka, komponen yang hilang atau salah, dan jembatan solder.

Langkah pertama dalam mengidentifikasi cacat penyolderan papan PCB adalah mengidentifikasi komponen. Untuk melakukan ini, Anda perlu menetapkan penunjuk referensi, yaitu huruf yang diikuti dengan angka. Setiap komponen pada PCB memiliki penunjuk referensi yang unik. Sebagai contoh, resistor dilambangkan dengan R, sedangkan kapasitor dilambangkan dengan C. Huruf-huruf ini dapat bervariasi dari huruf standar, tetapi merupakan cara yang dapat diandalkan untuk mengidentifikasi komponen. Langkah selanjutnya adalah memilih jenis uji inspeksi. Hal ini dapat dilakukan dengan menggunakan AOI, ICT, atau pengujian fungsional.

Metode pemeriksaan papan PCB yang umum lainnya adalah pemeriksaan sinar-X. Teknik ini menggunakan mesin yang memungkinkannya untuk memeriksa PCB dari berbagai sudut. Saat ini, PCBA123 menggunakan sistem pemeriksaan sinar-X 2D, tetapi berencana untuk meningkatkan ke AXI 3D dalam waktu dekat.

Tindakan pencegahan

Cacat penyolderan papan PCB dapat disebabkan oleh sejumlah masalah yang berbeda. Beberapa masalah dapat dengan mudah diidentifikasi, sementara yang lain mungkin tidak terlihat. Cara terbaik untuk memeriksa papan PCB dari cacat ini adalah dengan menggunakan sistem inspeksi visual otomatis. Sistem inspeksi otomatis dapat mendeteksi cacat pada sambungan solder dan polaritas kapasitor, misalnya.

Salah satu penyebab paling umum dari cacat penyolderan papan adalah, solder tidak dibasahi sepenuhnya. Hal ini dapat terjadi ketika solder diterapkan terlalu sedikit panas atau dibiarkan di papan terlalu lama. Papan yang tidak dibasahi dengan benar dapat menyebabkan masalah struktural, dan itu akan mempengaruhi kinerja PCB secara keseluruhan. Namun, ada beberapa langkah pencegahan yang dapat diambil untuk meningkatkan pembasahan papan.

Alasan lain untuk cacat penyolderan papan PCB adalah desain stensil yang tidak tepat. Ketika stensil tidak dirancang dengan benar, hal itu dapat menyebabkan bola solder tidak terbentuk sepenuhnya. Menggunakan stensil yang tepat dapat mencegah cacat bola solder dan memastikan kinerja sirkuit.

Alasan Bahan Resin PCB Retak di Bawah Bantalan BGA Selama Pemrosesan SMTP

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Alasan Bahan Resin PCB Retak di Bawah Bantalan BGA Selama Pemrosesan SMTP

Retaknya bahan resin PCB terjadi karena adanya uap air yang terperangkap. Penyebabnya adalah suhu penyolderan yang tinggi yang menghasilkan peningkatan tekanan uap. Keretakan juga dapat terjadi karena ekspansi termal papan menyebabkan jarak antara bantalan BGA berubah. Untuk mengurangi risiko jenis kesalahan ini, lapisan pad alternatif dapat digunakan, yang mengurangi dampak termal pada paket yang berdekatan.

Kelembaban yang terperangkap menyebabkan bahan resin PCB retak

Kelembaban yang terperangkap dapat menyebabkan berbagai kegagalan PCB, termasuk delaminasi, melepuh, dan migrasi logam. Hal ini juga dapat mengubah konstanta dielektrik dan faktor disipasi, sehingga mengurangi kecepatan pengalihan sirkuit. Kelembaban juga meningkatkan tingkat stres pada berbagai fitur PCB, termasuk bantalan tembaga dan bga. Hal ini juga dapat menyebabkan oksidasi pada permukaan tembaga, yang mengurangi keterbasahan lapisan akhir. Selain itu, hal ini dapat meningkatkan terjadinya korsleting listrik dan terbuka. Hal ini sangat bermasalah karena fabrikasi PCB melibatkan banyak langkah yang melibatkan penggunaan air.

Selama pemrosesan smt, uap air yang terperangkap dapat mengakibatkan retakan pada bahan resin PCB. Karena itu, produsen PCB harus memperhatikan ukuran bukaan masker solder. Ukurannya harus lebih kecil dari luas lahan yang diinginkan. Jika area pad SMD terlalu besar, akan sulit untuk merutekan bola solder.

Suhu penyolderan aliran ulang meningkatkan tekanan uap

Berbagai faktor dapat memengaruhi pelengkungan paket selama penyolderan BGA. Ini termasuk pemanasan istimewa, efek bayangan, dan permukaan yang sangat reflektif. Untungnya, proses reflow konveksi paksa dapat mengurangi efek-efek ini.

Suhu reflow yang tinggi dapat menyebabkan kerusakan tonjolan solder. Kenaikan suhu dapat menyebabkan pengurangan tinggi sambungan solder, sehingga menghasilkan kebuntuan solder yang lebih kecil dari tinggi asli tonjolan solder.

Bentuk bantalan sambungan juga merupakan faktor penting dalam menentukan kekokohan sambungan solder. Disarankan untuk menggunakan bantalan yang lebih besar dan lebih lebar daripada yang lebih kecil. Area yang lebih luas akan meningkatkan kemungkinan retak.

Fluks norak mengurangi dampak termal pada paket yang berdekatan

Fluks norak adalah bahan termoset yang digunakan selama penskalaan chip dan perakitan paket flip chip. Komposisinya terdiri dari bahan kimia reaktif, yang dilarutkan dalam bahan pengisi selama pemanasan reflow. Setelah sembuh, fluks lengket menjadi bagian dari struktur kerja bersih paket akhir.

Sebagai bahan pembasah kimiawi, fluks memfasilitasi proses penyolderan dengan mengurangi tegangan permukaan solder cair, sehingga memungkinkannya mengalir lebih bebas. Fluks dapat diaplikasikan dengan mencelupkan, mencetak, atau memindahkan pin. Dalam banyak kasus, fluks ini kompatibel dengan lapisan bawah epoksi. Hal ini memungkinkan mereka untuk mengurangi dampak termal dari paket yang berdekatan selama pemrosesan smt.

Menggunakan fluks yang lengket mengurangi dampak termal pada paket yang berdekatan selama penyolderan. Namun, metode ini memiliki keterbatasan. Beberapa faktor dapat menyebabkan fluks gagal. Kotoran dalam fluks dapat mengganggu proses penyolderan, membuat sambungan solder menjadi lemah. Selain itu, diperlukan peralatan yang mahal untuk membersihkan pasta solder dengan benar sebelum menyolder.

Hasil akhir pad alternatif

Perilaku perambatan retak pada PCB dapat dipengaruhi oleh lapisan pad yang digunakan. Berbagai metode telah dikembangkan untuk mengatasi masalah ini. Salah satu metode ini adalah penggunaan pengawet kemampuan solder organik. Pengawet ini efektif melawan oksidasi pad. Selain itu, ini membantu menjaga kualitas sambungan solder.

Geometri pad menentukan kekakuan papan. Hal ini juga menentukan pembukaan masker solder. Ketebalan papan dan bahan yang digunakan untuk membuat setiap lapisan memengaruhi kekakuan papan. Umumnya, rasio pad-ke-perangkat 1:1 adalah optimal.

Metode pengujian untuk mengkarakterisasi keretakan bahan resin PCB

Berbagai metode pengujian tersedia untuk mengkarakterisasi kinerja bahan resin PCB selama pemrosesan SMTP. Ini termasuk karakterisasi listrik, metode tidak rusak, dan uji sifat fisik. Dalam beberapa kasus, kombinasi dari pengujian ini dapat digunakan untuk mendeteksi kawah pad.

Salah satu metode pengujian untuk mengidentifikasi keretakan adalah dengan mengukur jarak antar pin. Biasanya, 0,004 inci dapat diterima untuk paket periferal, dan 0,008 inci dapat diterima untuk Paket BGA. Metode pengujian lain untuk mengkarakterisasi bahan resin PCB adalah dengan mengukur koefisien muai panas. Koefisien ini dinyatakan sebagai ppm / derajat Celcius.

Metode lainnya adalah teknik flip chip. Proses ini memungkinkan fabrikasi substrat BGA flip chip dengan kepadatan tinggi. Ini banyak digunakan dalam kemasan IC tingkat lanjut. Proses flip chip membutuhkan hasil akhir berkualitas tinggi yang seragam dan bebas dari kotoran agar dapat disolder. Ini biasanya dicapai dengan pelapisan nikel tanpa listrik di atas bantalan tembaga dan lapisan tipis emas imersi. Ketebalan lapisan ENIG tergantung pada masa pakai rakitan PCB, tetapi biasanya sekitar 5 um untuk nikel dan 0,05 um untuk emas.

Apakah Jalur Kontrol Impedansi Meningkatkan Biaya Papan PCB?

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Apakah Jalur Kontrol Impedansi Meningkatkan Biaya Papan PCB?

Impedance control is an important feature that affects the performance of printed circuit boards. The manufacturer can control the impedance of a PCB board by adjusting the trace configuration and the dielectric constant of the PCB material. It is essential for board designers to convey their impedance requirements in advance.

Impedance control line reduces EMI issues

Using an impedance control line reduces EMI issues by reducing the current that can flow through a line. As we know, the higher the current, the higher the emissions. However, by using an impedance control line, you can significantly reduce the current to a level that will not cause problems with your equipment.

It increases cost

Adding an Impedance Control Line (ICL) to a PCB board can increase the cost of the board. This component is necessary for RF products and uses a multilayer FR-4 construction. The plated through holes on one layer link tracks on other layers. Alternatively, complex structures use buried and blind vias, which connect the inner layers only. The most expensive ICLs go through all layers of the board.

When specifying the impedance control line, remember to be as detailed as possible. If you don’t, the fabricator may have to make several round-trips with the design team to confirm a critical specification. This can waste valuable project time. By providing as much detail as possible, you can help to ensure a smooth and efficient project. Moreover, you must remember that only one trace width is allowed per PCB layer, so it is important to specify which figure you will use.

Impedance is a vital parameter of PCBs. This parameter ranges between 25 and 120 ohms on average. Generally, Impedance is a combination of inductance and capacitance, and is dependent on the frequency. In some digital applications, controlled impedance is necessary to maintain signal clarity and data integrity.

It affects quality

An impedance control line can affect the quality of a PCB board in a variety of ways. Unmatched impedance can cause reflections of signal waves, resulting in a signal that is not a pure square wave. This can cause electromagnetic interference and localized radiation, and can affect sensitive components. The proper impedance control line for a PCB design is essential for the reliability of the PCB.

For the best quality PCB, choose a manufacturer with an experienced team of designers and engineers. Make sure they follow quality standards and deliver your order on time. Generally, it is recommended to use a manufacturer with at least 10 years of experience. Some companies also offer services at cheaper rates.

Controlled impedance is essential for circuit boards with high-speed signals and high-power devices. Controlled impedance PCBs ensure that these devices perform as expected, consume less energy and last longer. When designing a PCB, it’s important to consider the impedance level of copper traces. If they aren’t matched, a single reflection pulse can disrupt a circuit and bleed over to neighboring components.