Silicone Molding: Driving Innovation Across Industries

Silicone molding is essential for industries that demand durability, flexibility, and reliability. Its versatile properties enable manufacturers to create application-specific solutions, from seals that endure extreme temperatures to tubes resistant to harsh chemicals. As industries push for higher performance and safety standards, silicone molding continues to drive innovation. Boyd supports this progress by delivering advanced silicone solutions across eMobility, Medical, Industrial, and Food and Beverage sectors, ensuring compliance with industry certifications and providing precision through global manufacturing capabilities.

Advanced Silicone Seals for EV Components

Boyd provides silicone solutions for motor coolant seals, battery housing seals, and charging port seals in the fast-evolving eMobility sector. Our battery housing seals absorb extreme mechanical energy, ensuring efficient assembly and leak-free performance. Boyd’s proprietary silicone polymers offer durable, long-lasting performance in EV applications by resisting oils, liquids, and harsh chemicals. Our charging port seals, engineered with UV and weather-resistant silicone compounds, ensure long flex life and reliable performance in challenging outdoor environments.

Precision Silicone for Medical Devices: Ensuring Patient Safety

Silicone Solutions for Industrial Durability

Boyd’s silicone molding solutions for industrial applications include silicone tubes, assemblies, and seals. We craft formulas and geometries designed to withstand harsh environments like extreme temperatures, high flex cycles, and chemical exposure. Our silicone seals deliver leak-free performance against oils, gases, and other liquids, while providing long-term mechanical damping. These solutions ensure superior protection and reliability, optimizing operational efficiency for industrial systems.

From Dispensing to Packaging: Silicone for the Food and Beverage Industry

Trusted Partner for Regulated Applications: Boyd’s Silicone Molding

Boyd leverages global material innovation and decades of silicone molding expertise to lead in delivering critical silicone solutions for regulated applications. Our technical design and engineering teams provide support with material selection, design for manufacturing (DFM), and prototyping, while our global manufacturing footprint ensures efficient production and distribution. From clean room manufacturing to top silicone formulations, Boyd is your trusted partner for silicone molding solutions.

Whether in eMobility, Industrial, Medical, or Food and Beverage industries, Boyd engineers silicone molding applications for performance, safety, and reliability. Connect with us to explore how we can help innovate your next project.

Aluminum Dip Brazing: Strong, Efficient, and Cost-Effective Joining

Dip brazing offers numerous benefits. Each project requires little to no equipment, keeping tooling costs low and allowing for easy configuration changes with common fixtures. The process creates sturdy, leak-proof, EMI-shielded joints, improving overall strength. This method also ensures higher quality at a lower cost by brazing many smaller parts simultaneously. Aluminum dip brazing produces joints with better conductivity than adhesive or mechanical attachments. It brazes all joints of a component simultaneously, producing durable components quickly and evenly.

What is Dip Brazing?

Dip brazing is a metal fabrication process that joins metal surfaces by immersing a pre-assembled component containing braze alloy into a molten bath of the flux. This process uses capillary action to draw the molten braze alloy between the tightly fitted parts, forming a strong and permanent thermal and mechanical bond when it cools.

Why Use Dip Brazing?

Dip brazing efficiently joins metal surfaces across multiple planes in a single 60-second operation, simplifying assembly compared to the multi-step process of welding, which requires careful structural planning and additional time.

In contrast, vacuum brazing effectively joins components in the same plane, such as liquid cold plates and tube-and-fin heat exchangers but lacks dip brazing’s versatility across different planes. Welding, which handles complex structural requirements and provides higher joint strength, uses a fluxless process. Dip brazing efficiently handles multiple component planes in one operation, providing a balanced alternative to welding and vacuum brazing in liquid cooling systems.

When Not to Use Dip Brazing?

Liquid cooling applications or sensitive applications that demand meticulous cleaning are better suited to vacuum brazing or welding. Dip brazing can leave flux reside in smaller cavities that may be difficult to flush out in complex assemblies, which pose risks for sensitive electronics.

What Products and Applications Use Dip Brazing?

Dip brazing is a critical manufacturing process for a variety of products and applications that need high durability and reliability. Dip brazing creates robust and reliable joints essential to maximize performance and longevity across industries such as aerospace, defense, automotive, and electronics. Its versatility and reliability make it indispensable to fabricate intricate metal assemblies and components quickly with high reliability.

Chassis and Enclosures:

In the aerospace sector, dip brazing provides the structural integrity needed for aircraft frames and components. Dip brazing makes these assemblies better able to endure rigorous environmental conditions while ensuring optimal performance and safety.

In electronics applications, manufacturers use dip brazing to produce equipment enclosures. Devices such as communication systems, radar equipment, and power electronics rely on dip brazed enclosures for EMI shielding and structural stability.

The automotive industry uses dip brazing to fabricate chassis components and enclosures. This process ensures the durability and performance of vehicle frames, heat exchangers, and battery enclosures under demanding conditions.

Machined Components:

Dip brazing enhances the efficiency and durability of heat exchangers in HVAC systems, automotive cooling systems, and industrial machinery by creating robust joints for optimal heat transfer. Manufacturers utilize dip brazing for precision instruments that require exact alignment and structural integrity, such as optical mounts, sensor housings, and medical equipment parts. Power transmission equipment, including gearboxes, couplings, and shaft assemblies, rely on dip brazing for durable and reliable joints, ensuring smooth operation and longevity in critical systems.

Common Dip Brazing Materials

While Boyd only uses aluminum-based alloys, dip brazing relies on a selection of common materials tailored to ensure strong, reliable joints across various metal compositions. Among the critical components of the dip brazing process are base metals and brazing alloys.

Base Metals:

Aluminum Alloys: Ideal for aluminum and its alloys due to compatibility and low melting temperatures.

Boyd only specializes in aluminum alloy dip brazing.

Copper Alloys: Suitable for brazing copper, brass, and bronze components. Steel: Used for a variety of applications requiring robust, durable joints.

Stainless Steel: Offers corrosion resistance and strength, commonly brazed for critical applications.

Nickel Alloys: Suitable for high-temperature materials such as stainless steel and nickel alloys.

Titanium Alloys: Used in aerospace and other industries where lightweight, high-strength joints are required.

Magnesium Alloys: Commonly brazed for applications requiring lightweight components.

Brazing Alloys:

Aluminum-Based Alloys: Specifically designed for brazing aluminum and its alloys, featuring low melting temperatures and excellent compatibility.

Since Boyd only does aluminum dip brazing, we only use aluminum dip brazing alloys.

Silver-Based Alloys: Versatile and widely used for joining steel, stainless steel, copper, and brass components.

Copper-Based Alloys: Often chosen for brazing copper, brass, and bronze components, offering good strength and conductivity.

Nickel-Based Alloys: Suitable for joining high-temperature materials such as stainless steel and nickel alloys, providing strong and durable joints.

Fluxes:

Boyd’s large-scale dip brazing installation maintains only a single flux chloride-based flux. Other dip brazing installations can use different fluxes, based upon the parent and braze alloys.

Borax-Based Fluxes: Commonly used for aluminum and aluminum alloys, facilitating the removal of oxides and ensuring good wetting of the brazing alloy.

Fluoride-Based Fluxes: Effective for brazing stainless steel and other high-temperature alloys, aiding in the removal of surface contaminants and promoting proper alloy flow.

Chloride-Based Fluxes: Suitable for brazing copper and brass components, assisting in the removal of oxides and ensuring strong, clean joints.

These materials are carefully selected based on factors such as base metal compatibility, operating conditions, and specific application requirements, ensuring optimal performance and reliability in dip brazing processes.

Dip Brazing Process

The dip brazing process consists of a series of meticulous steps aimed at achieving strong, reliable bonds between metal components. Each step contributes to ensuring the quality and integrity of the final assembly. From surface preparation to cleaning, we carefully orchestrate every stage to facilitate the flow of molten brazing alloy and create robust joints.

1. Prepare the Assembly: Remove grease, oil, oxides, and scale from the component surfaces to ensure proper wetting of the alloy.
2. Select and Position Brazing Filler Metal: Choose the appropriate brazing filler metal, ensuring it contacts all the metals being joined.
3. Fixture the Assembly: Use fixtures to hold the assembled parts in place during brazing, using rods, hooks, or baskets.
4. Preheat the Assembly: Heat up the assembled components to just below the melting point of the filler metal to minimize furnace time and ensure uniform heating.
5. Perform Brazing: Move assembly from preheat and immerse it in the dip brazing furnace for a specific duration, allowing the brazing alloy to flow through the joint by capillary action.
6. Quench the Assembly: After brazing, rapidly cool the parts to a lower temperature to anneal the assembly and set the material’s mechanical properties. Boyd can use air, mist, or immersion to quench dip brazed assemblies.
7. Clean the Assembly: Remove flux residue from the components using chemical cleaning methods to ensure a clean finished assembly.
8. Age the Assembly: The part is artificially aged in an oven to lock in the mechanical properties set during the quench operation.

Key Considerations for Dip Brazing

For successful dip brazing, several key considerations must be addressed to ensure strong, reliable joints. This process involves immersing metals in a molten flux bath and requires meticulous planning. Attention to material compatibility, surface preparation, joint design, fixture design, brazing alloy selection, temperature control, flux selection, cooling and quenching, and quality control is crucial.

Material Compatibility: Ensure the materials being joined are compatible with both the brazing process and the brazing alloy. Consider the melting points, thermal expansion coefficients, and chemical compositions of the base metals and the brazing filler.

Surface Preparation: Proper cleaning and surface preparation are crucial for successful brazing. Remove any contaminants, such as oils, oxides, or coatings, from the surfaces to be joined to promote good wetting and adhesion of the brazing alloy.

Joint Design: Design the joint to facilitate capillary action and ensure the proper flow of the brazing alloy. Tight fits, appropriate gap sizes, and joint geometry promote capillary flow for stronger and more reliable joints.

Fixture Design: Use fixtures to hold the parts in the correct position during brazing and prevent distortion or misalignment. Design fixtures to withstand the thermal stresses of the brazing process and provide adequate support for the parts.

Brazing Alloy Selection: Choose the right brazing alloy to achieve the desired properties in the joint. Consider factors such as melting temperature, fluidity, strength, corrosion resistance, and compatibility with the base metals.

Temperature Control: Maintaining precise control over the brazing temperature ensures proper wetting and bonding of the brazing alloy without overheating the base metals. Ensure temperature uniformity throughout the assembly to prevent localized overheating or underheating.

Flux Selection: Select the appropriate flux for the application based on materials and brazing alloys. Ensure the flix bath is uniformly heated to the required temperature based on the materials being brazed.

Cooling and Quenching: Control cooling and quenching after brazing solidifies the brazing alloy, preventing the formation of undesirable metallurgical phases. Use controlled cooling rates to minimize residual stresses in the joint and reduce the risk of distortion.

Quality Control and Inspection: Regular inspection of the brazed joints for defects such as incomplete penetration, voids, cracks, or excess filler metal is crucial to ensure the quality and integrity of the assembly. Employing non-destructive testing methods such as visual inspection, leak testing, dye penetrant testing, or X-ray inspection as part of the quality control process.

Each of these factors plays a vital role in achieving the desired results and maintaining the structural integrity of the assembled components.

Why Use Boyd for Dip Brazing

Boyd’s total process control and breadth of experience enables us to meet demanding customer drawings and tolerances. Our expertise allows us to design dip braze assemblies, knowing how the material will react to each step of the manufacturing process. We can mitigate process-induced warping and distortion at each point through our deep skill and knowledge of the dip braze process to meet final dimensional requirements. And anything that we can’t adjust in the brazing process, we can machine in secondary operations on-site.

Boyd has been dip brazing complex assemblies for decades, making us an ideal partner when designing and fabricating your next project. We strive for excellence in each step of the dip brazing process and meticulously examine each detail of your application to ensure we produce a product that meets your requirements. Learn more about our chassis and enclosures or contact us today about your latest project.

Evolving Innovations across Diverse Industries

Boyd Connects Innovations between Industries

Learn more about the industries we serve in our Connecting Innovations 3D Tool:

Cool, Seal, Insulate, and Shield the Latest Technologies

Human Machine Interfaces and Displays

Environmental Sealing and Protection

Innovate with Boyd

With decades of invaluable experience and expertise, Boyd is at the forefront of innovation, designing, manufacturing, and fabricating cutting-edge thermal and engineered material solutions across innovative industries. Our engineering, manufacturing, and testing capabilities supported by extensive data and cutting-edge technology enable innovative solutions for specific applications, whether it is a cooling solution for ADAS systems or data centers, or HMI and display solutions for medical equipment.

We leverage our extensive material science expertise to identify the materials and components necessary to craft innovative solutions that prioritize performance, reliability, and energy efficiency. To explore the full spectrum of Boyd’s thermal and engineered material solutions or to discuss your project requirements in detail, visit boydcorp.com visit our website or talk with our team consultation with our experts.

In our previous blog, we went over the basics of Thermosiphons and how they work. While they’re all passive, two-phase systems that contain three basic parts (an evaporator, a fluid loop, and a condenser), the way that they’re constructed can be different depending on how they’re used.

In this blog, we’ll be reviewing the types of Thermosiphon configurations and some common applications for each.

What Are The Different Thermosiphon Configurations?

At Boyd, Thermosiphons are generally broken down into four main categories:

3D Direct Contact Loop Thermosiphon:

The working fluid absorbs heat and turns to vapor as it flows through the tubes in the base closest to the heat source and rises upwards from buoyancy. Manifolds lining the top and bottom of the assembly allow vapor and condensed fluid to distribute to each fin ensuring an isothermal 3D structure for consistent cooling. Natural or forced air flows through the near isothermal fin assembly to reject the heat to the surrounding environment with high efficiency. As heat is rejected from the system, the working fluid recondenses in the tubes in the fins, where it returns by gravity to the liquid manifold at the bottom and comes back to the evaporator for the process to be repeated.

Direct Contact Loop Thermosiphon:

The condenser features an attached high-density fin stack, where ambient forced airflow removes heat from the system. As heat is removed, the working fluid recondenses, flowing back through a return tube into the evaporator.

Air-to-Air Loop Thermosiphon:

Hot internal air from the enclosure evaporates the fluid on the evaporator coil, which rises through the vapor tube into the condenser coil. Forced external air flows through the condenser coil, recondensing the working fluid that then flows through the return tubes via gravity back down to the evaporator coil where the process repeats.

2D Thermosiphon Fin:

These embedded Thermosiphons, available in a loop, honeycomb, or microchannel design, significantly improve the performance of standard aluminum fins. 2D Thermosiphon Fins reduce weight and can reduce heat sink volumes by optimizing the thermal performance and are commonly used due to how they can be mixed and matched with other traditional thermal technologies.

While these are the general categories for Thermosiphons at Boyd, each can be customized to suit a wide variety of applications. If you have questions about our Thermosiphons or which one is ideal for your next project, visit our website or reach out to our experts.

The performance of high-powered lasers depends on effective cooling. High-powered lasers generate a significant amount of heat that must be removed from the laser system to avoid overheating critical components.

Optimizing a Laser by improving Liquid Cooling System

Carbon dioxide (CO2) lasers, excimer lasers, ion lasers, solid-state lasers, and dye lasers all use liquid cooling to remove excess heat. Laser liquid cooling helps accomplish three goals: maintaining a precise laser wavelength and higher output efficiency, achieving desired beam quality, and reducing thermal stress on a laser system. Recirculating chillers, liquid-to-liquid cooling systems, ambient cooling systems, cold plates, and heat exchangers are a few of the cooling technologies used in laser systems’ liquid cooling loops.

Low-powered lasers, such as small helium-neon or argon-ion lasers, may not require cooling or may come with their own cooling fan, which is generally sufficient. Some smaller gas lasers and many solid-state lasers contain their own built-in cooling system, usually a closed-loop heat exchanger. Larger gas lasers or other high-powered lasers, such as industrial CO2, large-frame argon- and krypton-ion lasers, and excimer lasers, however, typically require an external source of water flowing through the light-generating section of the laser system.

According to Coherent, Inc, manufacturer of lasers and laser systems, their ion lasers produce between 5kW and 55kW of waste heat as a by-product of the laser action. In order to avoid overheating critical components, Coherent notes the importance of efficiently removing this heat from the laser system and recommends the use of cooling water. Other laser systems may have more or less heat to remove, but the need for cooling remains.

Precise Wavelength, Optical Conversion Efficiency, & Beam Quality

One reason it’s important to remove excess heat from a laser system is that an increase in temperature will result in an increase in wavelength. This wavelength increase can compromise a laser system’s performance. Since diode laser wavelength increases with an increase in temperature, temperature must be uniform throughout the diode arrays in order to have high overall optical conversion efficiency in a pumping application. For example, the wavelength of light emitted from GaAs diode laser bars shifts at a rate of approximately 0.3nm/°C due to temperature related changes in bandgap energy and refractive index. To have a high overall optical conversion efficiency of light from GaAs diode bars in pumping some solid-state lasers, it is critical for the wavelength of light energy from each emitter to be within a very narrow wavelength band or within 1-2°C of each other. Cooling can help to keep the beam aligned in front of the emitter (± 5 microns).

Beam quality is also important in some laser applications. For example, with laser material processing, printing, marking, cutting, and drilling, strong beam focus is required. In high power lasers, the heating of the gain medium, such as the laser crystal, can cause thermal lensing. These thermal effects in the gain medium can affect laser wavefronts and therefore beam quality. With diode-pumped solid-state (DPSS) lasers, the crystal must be cooled and the temperature should be controlled to 0.5°C. (See Figures 1 and 2.)

Reduction of Thermal Stress

Lower operating temperatures can also increase the lifetime of a laser system’s components and reduce maintenance. This is especially true for DPSS lasers, since the mean time between failures (MTBF) is affected significantly by excess heat. It therefore makes sense for laser designers and manufacturers to integrate a cooling system within their laser. This helps ensure that the MTBF is extended and downtime is reduced, saving on operation and maintenance. By integrating a cooling system, it also helps the laser manufacturer ensure optimal laser system performance.

For low heat loads, recirculating chillers are usually the simplest solution as installation is so easy. At high heat loads, liquid-to-liquid cooling systems are more cost effective. However, their use is restricted to situations where chilled facility water is available. The necessity to plumb them into facility water may affect the locations they can be used in and the portability of the equipment.

If you have high heat loads and need to reject the heat to facility water, the choice between an LCS and a recirculating chiller with a water-cooled condenser depends on your set-point temperature. If your set-point temperature is higher than your maximum facility water temperature, an LCS is more cost-effective. However, if you need to cool close to or below the facility water temperature, you will need a refrigerant based chiller with a water-cooled condenser.

Recirculating Chillers

Commercially available recirculating chillers provide convenient cooling for a laser cooling. Compressor-based recirculating chiller coolant temperature can be set to between -5.0°C and 35.0°C and maintain ±0.1°C temperature stability, ensuring that the laser system is operating at the optimal wavelength and as efficiently as possible.

Recirculating chillers are also more environmentally friendly and cost-effective than using tap water. Chillers are closed-loop systems that use active refrigeration. They are used for cooling laser systems when there is a high heat flux, high ambient temperatures, or when a laser system requires a chilled environment, such as with excimer lasers. Typically they have cooling capacities ranging from 800W-6kW, a PID controller, large thermal mass tank, and advanced refrigeration control circuits to ensure that they maintain the tight temperature stability needed for laser system pointing stability and beam quality. In addition, recirculating chillers can provide consistent flow and pressure to the system while maintaining control of the quality of the coolant. It’s important to ensure that appropriate cooling system pressure is maintained, since excessive water pressure can create vibrations in the laser head.

Another benefit of recirculating chillers is that most of them are compatible with a variety of fluids. For example, many recirculating chillers are compatible with ethylene glycol (EGW) or propylene glycol (PGW) solutions, which offer corrosion and freeze protection. A recirculating chiller can also be fitted for compatibility with deionized (DI) water, including a DI cartridge to maintain a system’s required resistivity. (DI water is electrically inert.)

Liquid-to-Liquid Cooling Systems

Like a recirculating chiller, a liquid-to-liquid cooling system (LCS) offers precise temperature control of process water (fluid temperature to within ±0.5°C). However, it transfers heat to facility water via a liquid-to-liquid heat exchanger. An LCS is a solution for high heat-load or high ambient temperature applications where chilled facility water is available, as an LCS often has cooling capacities up to 20kW. For laboratories with several large lasers, an economical option may be the installation of a cooling tower on the roof of the facility to provide a common source of cooled water to all systems within the building. The cooling tower will exhaust heat outside of the building, helping to maintain a comfortable work environment. With an LCS, the facility water never comes in contact with laser system water. The heat is transferred from the cooling system fluid to facility water via the liquid-to-liquid heat exchanger. This is important because the water that circulates from facility cooling towers is often treated with fungicides, algaecides, and/or antifreeze, which may be too harsh for some laser components.

Ambient Cooling Systems

Ambient cooling systems, which have cooling capacities up to 3.5 kW, are a reliable alternative to refrigerated chillers and LCS for laser applications where precise temperature control and cooling below ambient temperature are not required. An ambient cooling system consists of a high performance heat exchanger, a fan, a pump, and a reservoir. Heat is moved from water circulating through the laser system into ambient air by a liquid-to-air heat exchanger and fan, hence the term “ambient cooling system”. Ambient cooling systems do not provide temperature stability, but they are a cost-effective means for heat dissipation.

Cold Plates & Heat Exchangers

Cold plates and heat exchangers are key components in liquid cooling loops for laser cooling. Cold plates are often used in conjunction with a recirculating chiller. Many lasers use tubed cold plates. However, aluminum vacuum-brazed cold plates that have liquid flow through channels are one type of cold plate more and more laser manufacturers are selecting. Manufacturers and end-users also use flat tube cold plate technologies. A cold plate may be mounted to the component requiring cooling, such as a thermoelectric, and will receive cold fluid from the chiller and transfer hot fluid back to the chiller. (See Figure 3.) Cold plates can also be designed as the electrodes of the laser system.

Heat exchangers are often found within cooling systems, such as chillers, LCS, and ambient cooling systems. Some laser manufacturers prefer to purchase a heat exchanger separately and integrate it themselves, connecting it to their own pump and reservoir.

Cooling Lasers with Liquid

High-powered laser systems require cooling for optimal performance and longevity. If maintaining a precise laser wavelength, beam quality, high output efficiency, and up-time are important, liquid cooling may be the answer. Recirculating chillers, LCS, ambient cooling systems, cold plates, and heat exchangers are becoming critical components in laser systems.

References

To determine outgoing temperature of the air, we use the ‘Air Flow’ chart using parameters 250 CFM and 2400 W.

Coherent®, “Laser Cooling Water Guidelines for Innova® Ion Laser Systems” p. 1.

Huddle, J.J., Chow, L.C., Lei, S., Marcos, A., Rini, D.P., Lindauer, S.J., II, Bass, M., and Delfyett, P.J., “Thermal Management of Diode Laser Arrays”, Semiconductor Thermal Measurement and Management Symposium, Sixteenth Annual IEEE, pp. 154-160, 2000.

Paschotta, R., “Thermal Lensing“, Encyclopedia of Laser Physics & Technology 2007.