pcb
Home > Blog

Posts Tagged ‘soldering’

What is hot bar soldering?
Thursday, November 7th, 2024

Hot bar soldering is a soldering method that uses heat and pressure to connect two or more materials together. The basic principle is to heat the surface of the material to a certain temperature to soften or melt it, and then apply a certain pressure to form a strong bond between the materials.

What is the hot bar process?

Hot bar soldering is a soldering method that applies pressure at a specific temperature. The process involves applying a pressure of 0.5 to 1.5N at a temperature above 200°C, so that the splitter brings the lead into contact with the soldering area and reaches the atomic distance, thereby generating an interatomic force to achieve the purpose of bonding.

What is hot bar soldering?

Specifically, during hot bar soldering, the temperature is usually above 200°C and the bonding strength is between 0.05 and 0.09N.

Hot bar soldering is widely used in the field of microelectronic surface assembly technology, especially in connecting flexible circuit boards and rigid circuit boards. The stability and efficiency of this process are essential to ensure the good quality of the product.

What temperature is hot bar soldering?

The temperature range of hot bar soldering is usually between 200-400°C below the melting point of the material. Because within this temperature range, the metal surface can melt and fuse together with the help of pressure, forming a high-quality weld.

Hot bar soldering is a method of joining two or more metal materials together by applying heat and pressure at the material joint, causing the material surface to melt and fuse together with the help of pressure.

Temperature is a critical parameter in the hot bar soldering process because it directly affects the quality of the weld and the structure of the metal. If the temperature is too low, the molten pool may not form, resulting in an incomplete connection; while too high a temperature may cause the material to melt excessively and damage the metal structure.

The temperature range of hot bar soldering is affected by many factors, including the properties of the metal, pressure, and welding time. The melting point of the metal is one of the most important parameters affecting the temperature selection, and welding is usually performed below the melting point of the material. Pressure and time also have a direct impact on the welding process because they have a direct impact on the contact and melting of the metal.

In practical applications, choosing the right temperature requires a comprehensive consideration of multiple factors. In the production of multilayer boards, the hot pressing temperature is generally between 150℃ and 180℃, and the specific temperature can be adjusted according to the type of glue used and the characteristics of the board.

In addition, the operating temperature range of high-frequency heat welding machines is generally between 100℃ and 300℃, and some special materials may require higher temperatures, up to 600℃.

What is a hot bar?

Hot pressing welding is a welding method that uses heat energy and pressure to melt and fuse two or more materials together at the contact surface. It is usually carried out at a temperature above 200°C and a certain pressure is applied to make the chopper bring the lead to contact the welding area and reach the atomic distance, thereby generating interatomic forces to achieve the purpose of bonding.

Why use hot air soldering?

The main reasons for using hot air soldering include its high efficiency, energy saving, environmental protection, high strength and wide application range.

What is hot bar soldering?
  • High efficiency: hot air welding has a fast speed and can greatly improve production efficiency.
  • Energy saving: Compared with traditional welding methods, hot air welding consumes less energy and can reduce energy consumption.
  • Environmental protection: Hot air soldering does not require the use of additional substances such as chemical agents, does not produce harmful substances, has little pollution to the environment, and meets environmental protection requirements.
  • High strength: The weld of hot air soldering is uniform and strong, and the material after welding is not easy to deform.
  • Wide range of applications: Hot air soldering is suitable for various metal materials, as well as a variety of plastic materials.

Is hot air soldering better than iron?

Hot air soldering and soldering iron each have their own advantages and disadvantages. The choice of which soldering method depends on the specific application requirements.

Advantages of hot air soldering

  • High efficiency: The efficiency of hot air soldering is usually higher than that of soldering iron, which is suitable for the removal and welding of large amounts of solder.
  • Temperature control: Hot air soldering can accurately control the welding process by adjusting the wind force and temperature, and is suitable for handling large-area welding tasks.
  • High safety: Hot air soldering guns generally use safe voltages and have anti-static functions, reducing the risk of electric shock and static damage to components.

Advantages of soldering irons:

What is hot bar soldering?
  • Accurate temperature control: The temperature control of soldering irons is more accurate, which is suitable for occasions that require precise welding, such as the welding of microelectronic components.
  • Flexible operation: The soldering iron is more flexible to operate and is suitable for delicate soldering work.
  • Low cost: The initial investment and operating cost of the soldering iron are usually low, which is suitable for users with limited budgets.

Applicable scenarios:

  • Hot air soldering: Suitable for removing and soldering a large amount of solder, such as circuit board repair and large-area soldering during manufacturing.
  • Soldering iron: Suitable for occasions that require precise soldering, such as soldering of microelectronic components and delicate circuit board repair.

In summary, hot air soldering and soldering iron have their own advantages and disadvantages, and which method to choose depends on the specific welding needs and application scenarios.

How to use bar solder?

The basic steps for using solder bar are as follows:

  • Preparation stage: First, put an appropriate amount of solder bar into the tin pot, connect the power supply and turn on the power switch, and adjust the temperature to about 250℃. Use the solder bar to tin the red heating tube until the tin surface covers the heating tube.
  • Melting process: When the tin bar begins to melt, new solder bar should be added in time until the molten tin surface reaches a suitable height. When there is no solder in the tin melting furnace, do not use the tin melting furnace to heat it.
  • Temperature control: The set temperature should not be too high to avoid accelerated oxidation of the tin surface. It is generally more appropriate to set it at around 300℃, and the specific temperature can be adjusted according to the use requirements.
  • Wave soldering process: During the wave soldering process, the content of the solder bar will continue to decrease. When the content is low to a certain extent, new solder bars should be added in time to maintain the height of the solder liquid and reduce the oxidation of the solder bar due to excessive tin wave drop.
  • Lead solder bar: If lead solder bar is used, it is necessary to remove impure copper and regularly check the solder composition in the soldering furnace.

How does laser soldering work?

Laser welding is an advanced welding method that uses a high-energy-density laser beam as a heat source to locally heat two or more metal or non-metal materials to a molten or partially molten state, and then quickly cools and solidifies to achieve connection.

The working principle of laser welding can be divided into the following steps:

  • The laser generates a high-power laser beam: The high-power laser beam generated by the laser is focused on the surface of the material to be welded through a lens or other optical elements to form a small spot.
  • The spot has a strong thermal effect on the surface of the material: The spot has a strong thermal effect on the surface of the material, causing it to quickly heat up to the melting point or boiling point, forming a liquid or gaseous molten pool or vaporization hole.
  • The laser beam moves along a predetermined trajectory: The laser beam moves along a predetermined trajectory, causing the molten pool or vaporization hole to extend along the direction of the weld. At the same time, due to surface tension and capillary action, adjacent materials flow into the molten pool or vaporization hole to fill the gap.
  • The molten pool or vaporization hole cools and solidifies rapidly: After the laser beam is removed, the molten pool or vaporization hole cools and solidifies rapidly to form a uniform, dense, and high-strength weld.

In short, hot pressing welding, as an efficient and reliable connection technology, plays an important role in modern industrial production. With the continuous advancement of science and technology, hot pressing welding technology will continue to develop and innovate to provide better connection solutions for the development of various industries.

You may also like

How to Clean Flux Off PCB? – Best Technology
Wednesday, July 31st, 2024

Flux is usually a mixture of rosin as the main component and is an auxiliary material to ensure the smooth progress of the PCB soldering process. Soldering is the main process of PCB assembly, flux is the auxiliary material used in soldering. The main function of flux is to remove the oxide of the solder and the base metal surface to be welded, so that the metal surface to achieve the necessary cleanliness.

Flux prevents the reoxidation of the surface during welding, reduces the surface tension of the solder, and improves the welding performance. The performance of flux directly affects the quality of electronic products. There are different types of solder paste flux, including rosin-based, water-soluble, and no-clean flux. Each has its specific applications and cleaning methods.

Types of Flux

  • Rosin Flux

This is one of the most commonly used fluxes in soldering. It includes activated rosin flux (RMA), which contains additional chemicals for enhanced cleaning of oxides, and non-activated rosin flux (RA), which offers basic cleaning for general purposes. Rosin flux is effective at preventing oxidation and improving solder flow, making it suitable for a wide range of electronic soldering applications.

  • Water-Soluble Flux

This type of flux uses water-soluble chemicals to provide strong cleaning action. It is easily removed with water, making it ideal for applications where thorough residue removal is necessary. Water-soluble flux is often used in automated soldering processes where post-soldering cleanup is a key concern.

  • No-Clean Flux

Designed to leave minimal, non-corrosive residue, no-clean flux does not require cleaning after soldering. This type of flux is beneficial in situations where cleaning is difficult or impractical, as it reduces post-soldering processing time while ensuring that the residue does not affect the performance of the PCB.

  • Organic Acid Flux

Contains organic acids like citric or formic acid, providing effective cleaning and fluxing. While it offers strong fluxing action, it is more corrosive compared to rosin fluxes. Organic acid flux is used in applications requiring robust cleaning, with careful consideration of the corrosion risk.

  • Solder Paste Flux

This flux is a combination of flux and solder powder, used in reflow soldering processes. It is commonly employed in surface-mount technology (SMT), where the paste is applied to PCB pads before component placement and reflow. Solder paste flux streamlines the soldering process by integrating fluxing and soldering into one step.

Is it Bad to Leave Flux on PCB?

There is obvious that leaving flux residue on a PCB surface can lead to several issues. Flux residues can attract moisture, resulting in corrosion of metal traces and component leads, which can compromise the integrity of the PCB over time. Some flux residues are conductive, potentially causing short circuits and affecting signal integrity, especially in high-frequency applications. Even no-clean flux can leave residues that impact sensitive components. Cleaning flux off the PCB can make sure the optimal performance and reliability of the overall product.

How to Remove Flux After Soldering?

We know leaving the flux on the PCBA surface is not a good thing, so how to remove it? Here we listing some common methods that manufacturers will used after soldering. Hope this information is helpful for you!

  • Isopropyl Alcohol (IPA)

Use high-purity IPA (90% or higher). Apply it to the flux residue with a brush or cotton swab, gently scrubbing the area to dissolve the flux. IPA evaporates quickly and is effective for most flux types.

  • Water Washing

Water washing is a common and straightforward cleaning method. It uses pure or deionized water to remove flux residues. This technique is simple, cost-effective, and easy to implement. However, water washing can potentially harm some PCBs and components if moisture accumulates on pads and pins, leading to short circuits or corrosion.

  • Solvent Cleaning

Solvent cleaning is an efficient method that dissolves flux residues using chemical solvents. The solvent is then rinsed or sprayed off to clear the flux. While this method provides rapid and effective cleaning, solvents can be costly and require careful handling due to their chemical properties and safety considerations.

  • Ion Cleaning

Ion cleaning is a high-tech approach that uses ion beams to clean the surface of PCBs. The high-energy and high-speed ion beams effectively remove contaminants and flux residues without damaging the PCB or components. However, ion cleaning equipment is expensive and requires specialized technology and support.

  • Oxidation Cleaning

Oxidation cleaning is a physical cleaning method where oxidizing agents convert flux residues into easily removable substances. This technique is suitable for PCBs and components that are not compatible with water or solvent cleaning. The cost of oxidizing agents can be high, and safety precautions are necessary due to their reactive nature.

  • Dry Ice Cleaning

Dry ice cleaning uses CO2 dry ice pellets as the cleaning medium. This method is efficient, environmentally friendly, and does not produce secondary pollution. During cleaning, high-speed CO2 dry ice pellets impact the flux residues on the PCB surface. The extremely low temperature of the dry ice causes the flux residues to become brittle, allowing them to be easily removed without damaging the PCB. This method offers a thorough cleaning solution while preserving the integrity of the circuit board.

FAQs

1. Can I use vinegar to clean flux off a PCB?

Vinegar can be used to clean certain types of flux, but it’s not as effective as IPA or specialized flux removers. It’s best to use a solvent designed for flux removal.

2. How often should I clean my PCB?

Clean your PCB after every soldering session to prevent residue buildup and ensure optimal performance.

3. Is it safe to use a hairdryer to dry a PCB after cleaning?

Yes, but use the lowest heat setting to avoid damaging sensitive components. Ensure the PCB is completely dry before powering it on.

4. Can I use a toothbrush for cleaning flux?

A toothbrush can be used, but a brush with anti-static properties is recommended to prevent static damage to the PCB.

5. Is no-clean flux really safe to leave on a PCB?

While designed to be left on, no-clean flux can still leave residues that may affect sensitive components. It’s best to clean it off for maximum reliability.

All in all, cleaning flux off your PCB is a crucial step to keep the reliability of your product. Remember, a clean PCB is a reliable PCB. Choose the right solvent, follow proper cleaning techniques, and your electronics will thank you with years of flawless performance.

For high-quality PCB & PCBA solutions and expert advice, choose Best Technology. We have more than 18 years in this field. Our commitment to excellence ensures your projects are in good hands. Contact us today to learn more about our products and services.

You may also like