Suggerimenti per la progettazione del layout del PCB dall'angolo di saldatura

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Suggerimenti per la progettazione del layout del PCB dall'angolo di saldatura

When designing a circuit board, there are several things to keep in mind, including the soldering angle. In general, you should avoid soldering with your face directly above the joint. To avoid this, try to place the power and ground planes on the inner layers of the board and align components in a symmetrical manner. In addition, avoid forming 90-degree trace angles.

Place power and ground planes in the inner layers of the board

When designing a circuit board, it is important to place power and ground planes in the inner layers. This helps minimize the amount of EMI, which can result from the proximity of high-speed signals to a ground plane. Ground planes are also necessary for reducing the amount of volt drop on a power rail. By placing power and ground planes in the inner layers, you can make room on the signal layers.

Once you’ve made sure that the power and ground planes are in the inner layers, you can move onto the next step of the process. In the Layer Stack Manager, add a new plane and assign a network label to it. After the network label is assigned, double-click on the layer. Be sure to consider the distribution of components, such as I/O ports. You also want to keep the GND layer intact.

Avoid soldering with your face directly above the joint

Soldering with your face directly above the joint is a bad practice because the solder will lose heat to the ground plane and you’ll end up with a brittle joint. It can also cause a lot of problems, including excessive buildup on the pin. To avoid this, make sure that the pins and pads are both evenly heated.

The best way to avoid soldering with your face directly above a joint is to use flux. This helps transfer heat, and it also cleans the metal surface. Using flux also makes the solder joint smoother.

Place components with the same orientation

When laying out a PCB layout, it’s important to place components with the same orientation from the soldering angle. This will ensure proper routing and an error-free soldering process. It also helps to place surface mount devices on the same side of the board, and through-hole components on the top side.

The first step in laying out a layout is to locate all the components. Typically, components are placed outside the square outline, but this does not mean that they cannot be placed inside. Next, move each piece into the square outline. This step helps you understand how components are connected.

Avoid creating 90-degree trace angles

When designing a PCB layout, it is important to avoid creating 90-degree trace angles. These angles result in narrower trace width and increased risks of shorting. If possible, try to use 45-degree angles instead. These are also easier to etch and can save you time.

Creating 45-degree angle traces on your PCB layout will not only look better, but it will also make the life of your PCB manufacturer easier. It also makes copper etching easier.

Using 45-degree angles for etching

Using 45-degree angles for solder in PCB layout design is not a common practice. In fact, it’s a bit of a relic from the past. Historically, circuit boards have had right-angled corners and a lack of any solder mask. This is because early circuit boards were made without solder masks, and the process involved a process called photosensitization.

The problem with using angles larger than 90 degrees is that they tend to lead to copper migration and acid traps. Likewise, traces drawn on a layout at a right angle do not get as much etching. In addition, 90-degree angles can create partially traced angles, which can result in shorts. Using 45-degree angles is not only easier but safer, and will result in a cleaner and more accurate layout.

Choosing the appropriate package size

When planning a PCB layout, you must pay attention to the soldering angle and package size of the components on the board. This will help you minimize shadow effect problems. Typically, solder pads must be spaced at least 1.0mm apart. Also, be sure that through-hole components are placed on the top layer of the board.

The orientation of the components is another important factor. If the components are heavy, they should not be placed in the center of the PCB. This will reduce board deformation during the soldering process. Place smaller devices near the edges, while larger ones should be placed on the top or bottom side of the PCB. For example, polarized components should be aligned with positive and negative poles on one side. Also, be sure to place taller components next to smaller ones.

Tre consigli per ridurre i rischi della progettazione di PCB

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Tre consigli per ridurre i rischi della progettazione di PCB

Esistono molti modi per ridurre il rischio associato alla progettazione di PCB. Alcuni di questi includono l'orientamento di tutti i componenti nella stessa direzione e l'uso di vias multipli alle transizioni di strato. Altri includono la separazione dei circuiti analogici da quelli digitali e l'allontanamento dei circuiti oscillanti dal calore.

Orientare i componenti nella stessa direzione

Il rischio di progettazione dei circuiti stampati viene ridotto al minimo orientando i componenti nella stessa direzione. Questa pratica aiuta a minimizzare i tempi di assemblaggio e manipolazione, riducendo le rilavorazioni e i costi. Orientare i componenti nella stessa direzione aiuta anche a ridurre la probabilità che un componente venga ruotato di 180 gradi durante il test o l'assemblaggio.

L'orientamento dei componenti inizia con la costruzione dell'impronta. Un ingombro errato può portare a componenti non collegati correttamente. Ad esempio, se un diodo è orientato con il catodo rivolto in una direzione, il catodo potrebbe essere collegato al pin sbagliato. Inoltre, i componenti a più pin possono essere installati con l'orientamento sbagliato. Questo può far sì che i componenti galleggino sulle piazzole o si alzino, causando un effetto tombstone.

Nei circuiti stampati più vecchi, la maggior parte dei componenti era orientata in un'unica direzione. Tuttavia, i circuiti moderni devono tenere conto dei segnali che si muovono ad alta velocità e sono soggetti a problemi di integrità dell'alimentazione. Inoltre, è necessario tenere conto delle considerazioni termiche. Di conseguenza, i team di layout devono trovare un equilibrio tra prestazioni elettriche e producibilità.

Utilizzo di più vias nelle transizioni di strato

Sebbene non sia possibile eliminare completamente i vias alle transizioni di strato, è possibile ridurre al minimo l'irradiazione da essi utilizzando vias di cucitura. Questi vias devono essere vicini ai vias di segnale per ridurre al minimo la distanza percorsa dal segnale. È importante evitare l'accoppiamento in questi vias, poiché ciò compromette l'integrità del segnale durante il transito.

Un altro modo per ridurre il rischio di progettazione dei circuiti stampati è quello di utilizzare più vias nelle transizioni di strato. In questo modo si riduce il numero di pin su un PCB e si migliora la resistenza meccanica. Inoltre, contribuisce a ridurre la capacità parassita, particolarmente importante quando si ha a che fare con le alte frequenze. Inoltre, l'uso di più vias alle transizioni di livello consente di utilizzare coppie differenziali e componenti ad alto numero di pin. Tuttavia, è importante mantenere basso il numero di segnali paralleli, per ridurre al minimo l'accoppiamento dei segnali, la diafonia e il rumore. Si consiglia inoltre di instradare separatamente i segnali di disturbo su strati separati per ridurre l'accoppiamento dei segnali.

Allontanare il calore dai circuiti oscillanti

Una delle cose più importanti da tenere a mente quando si progetta un circuito stampato è mantenere la temperatura più bassa possibile. Per raggiungere questo obiettivo è necessaria un'attenta disposizione geometrica dei componenti. È inoltre importante che le tracce ad alta corrente siano lontane dai componenti termicamente sensibili. Anche lo spessore delle tracce di rame svolge un ruolo importante nella progettazione termica del PCB. Lo spessore delle tracce di rame deve fornire un percorso a bassa impedenza per la corrente, poiché un'elevata resistenza può causare una significativa perdita di potenza e la generazione di calore.

Tenere lontano il calore dai circuiti oscillatori è una parte fondamentale del processo di progettazione della scheda. Per ottenere prestazioni ottimali, i componenti dell'oscillatore devono essere collocati vicino al centro della scheda, non vicino ai bordi. I componenti vicini ai bordi della scheda tendono ad accumulare molto calore e questo può aumentare la temperatura locale. Per ridurre questo rischio, i componenti ad alta potenza dovrebbero essere collocati al centro della scheda. Inoltre, le tracce ad alta corrente devono essere distanti dai componenti sensibili, poiché possono causare l'accumulo di calore.

Evitare le scariche elettrostatiche

Evitare le scariche elettrostatiche durante la progettazione di circuiti stampati è un aspetto essenziale dell'ingegneria elettronica. Le scariche elettrostatiche possono danneggiare i chip semiconduttori di precisione all'interno del circuito. Può anche fondere i fili di collegamento e cortocircuitare le giunzioni PN. Fortunatamente, esistono molti metodi tecnici per evitare questo problema, tra cui un layout e una stratificazione adeguati. La maggior parte di questi metodi può essere eseguita con poche modifiche al progetto.

Innanzitutto, è necessario capire come funzionano le ESD. In poche parole, l'ESD provoca il passaggio di un'enorme quantità di corrente. Questa corrente viaggia verso la terra attraverso il telaio metallico del dispositivo. In alcuni casi, la corrente può seguire più percorsi verso la terra.

Cause e soluzioni della pseudo-saldatura di PCBA

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Cause e soluzioni della pseudo-saldatura di PCBA

PCBA pseudo soldering is a problem that affects the quality of the finished PCBA. It can cause losses due to rework, which reduces the production efficiency. However, detecting and solving pseudo soldering problems can be done using inspection.

Reflow soldering

Reflow soldering is one of the most common methods of PCB assembly. This method is often combined with wave soldering. It can greatly affect the quality of the assembled board, which is why the process requires a proper understanding of PCB construction.

To ensure a quality solder joint, it is important to follow several guidelines. First, it is important to check the alignment of the printed board. Make sure that the print is properly aligned before applying the solder paste. Second, clean the stencil bottom regularly. Third, reflow soldering can result in a tombstone effect, otherwise known as the Manhattan effect. The tombstone effect is caused by force imbalances during the reflow soldering process. The end result looks like a tombstone in a cemetery. In reality, the tombstone effect is an open circuit on a defunct PCB.

During the preheat stage, a small portion of the solder paste can gasify. This can cause a small amount of solder to leave the soldering pad, especially under chip components. In addition, melted solder paste may push out under sheet-type resistor-capacitor units.

Wave soldering

PCB assembly process defects, including tombstoning, occur in a variety of ways. One of the main causes is inadequate soldering quality. Poor soldering results in cracks that appear on the surface of discrete components. These defects can be easily corrected with rework, although they can create a wide range of problems in the assembly process.

PCB manufacturers need to be aware of these defects to prevent them from occurring in the production process. These defects may be hard to detect, but different technologies and methods can help detect them and minimize their impact. These methods allow manufacturers to prevent soldering defects before they occur and help them produce high-quality products.

Stencil thickness

PCB pseudo-soldering can be caused by a number of factors. For example, an incorrect stencil can lead to over-applied solder paste on the components. Moreover, a poorly shaped stencil can result in solder balling or discrete deformities. These issues can be resolved by reducing the thickness of the stencil or the aperture size. However, these steps should be done with caution because even the slightest undersizing can lead to major problems in later PCB assembly stages.

PCB pseudo-soldering can be prevented by properly applying flux. Flux is a thixotropic agent that makes solder paste have pseudo-plastic flow characteristics. This means that it will reduce in viscosity when passing through the stencil’s apertures, but will recover once the external force is removed. The amount of flux used in solder paste should be eight to fifteen percent. Lower values will result in a thin solder film, while higher ones will cause excessive deposits.

Squeegee pressure

PCBA pseudo soldering, also known as cold soldering, is an in-between stage of the soldering process in which a portion of the board is not fully soldered. This can compromise the quality of the PCB board and affect its circuit characteristics. This defect may result in the scrapping or disqualification of the PCB board.

To control the squeegee pressure can solve the problem of pseudo soldering. Too much pressure will smear the solder paste and cause it to spread across the PCB’s flat surface. Alternatively, too little pressure will cause the solder paste to scoop up into larger apertures, causing the PCB to be covered with too much paste.

Research on PCB Plug Mechanism and Effective Control Method

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Research on PCB Plug Mechanism and Effective Control Method

Pressurized microchambers

A pressurized microchamber is an effective means of transporting liquid in lab-on-PCB devices. It works by storing pneumatic energy and releasing it through an opening in a microvalve. The microvalve is electrically activated, using a gold wire of about 25 m in diameter.

Lab-on-PCB devices are currently being developed for a wide range of biomedical applications, but they are not yet commercially available. However, research in this field is growing rapidly and there is a significant potential for obtaining marketable devices. Various flow-driving methods have been developed, including electrowetting on dielectrics, electroosmotic flow driving, and phase-change-based flow driving.

The use of external sources for moving liquids inside lab-on-PCB systems has long been used in research, but it is not a particularly practical solution for a portable system. External syringe pumps also reduce the portability of the device. However, they provide an interesting opportunity to integrate sensors and actuators in a microfluidic device.

Electroosmotic pumps are also commonly integrated on PCBs for fluid manipulation. They offer a low-cost, pulse-free continuous flow of fluid, but require narrow microchannels and external liquid reservoirs. Inappropriate activation can result in electrolysis and microchannel blocking. Moreover, copper electrodes are not ideal because they can cause fluid contamination and microchannel blocking. Further, copper electrodes require additional fabrication steps and increase cost.

Laboratory-on-PCBs

Laboratory-on-PCBs (LoP) is a type of device that integrates an electronic circuit onto a PCB. This type of device is used to perform various experiments in electronic circuits. It is also used in applications that require the integration of different materials. These devices are compatible with flow-driving techniques and can also be produced by photolitographic or dry resist methods. Moreover, these devices also incorporate surface mounted electronic components that are designed to measure data. One such example is a device which integrates an embedded blue LED and an integrated temperature sensor.

Another option for moving liquids in Lab-on-PCBs is to use pressurized microchambers. The pressurized chambers can store pneumatic energy and can be released by opening a microvalve. The microvalves are activated electrically. One advantage of this type of mechanism is that it is portable and can be used multiple times. Moreover, it can withstand high pressures.

One of the main challenges of implementing microvalves into PCBs is the difficulty of integrating them into the PCB. It is also difficult to integrate actuators with moving parts into a PCB. However, researchers have developed micropumps that are PCB-based, and made use of piezoelectric actuators.

The process of using lab-on-PCBs to control liquids is highly complex and can be quite difficult. There are numerous drawbacks of this method, and the main difficulty is the complex fabrication process. Moreover, the method of assembly of LoPs also adds to the complexity of the device.