Silver is the new gold: Important applications of silver paste in the solar industry

In the field of nanoscience, silver particles are subjected to a number of industries because of their properties on antibacterial, catalytic, electronic and optical materials. The research on silver nano-particles has also rapidly developed in the past 10 years. With the help of methods like chemical reduction or micro-emulsion, it has become possible to prepare conductive metal nanoparticles which can be applied for metal paste as well. Most commonly, a thick film type of silver paste comprises a functional phase, further consisting of various shapes (spherical, say for example) and different sizes (nanometer, micrometer etc).

A homogenous silver paste is a rather stable system, wherein all components are soluble in the solvent and no particle or solid phase is excluded. The paste is able to avoid the agglomeration of particles, applied in traditional paste types, while eliminating the constraints of particle pattern and size. In recent years, the silver printing circuit board is known to have a structure in which the conducting silver paste goes under screen printing on a PET film for formation of circuits. Silver paste for the purpose of screen printing for circuit formation utilises silver in conductive particles.

Although, one disadvantage associated with ion migration is that it can occur easily. This can however, be handled with a greater amount of ease, since it is highly resistant as compared to copper, which has a specific resistance level, and hence the wide usage of the material. Polymer type conductive paste finds another set of applications. The silver conductive particles come in contact with each other, ensuring a greater electrical conductance. However, with this conductive mechanism, there is contact resistance that occurs between the conductive particles. Silver paste utilised in the ceramics substrate is again composed of glass frit and conductive silver particles.  As one of its important applications, silver paste plays an important role in dye sensitized solar cells, which has been attracting a high number of audience and attention to become the next generation of solar cells.

Some important benefits of silver paste includes:

1.High electrical conductivity

2.Lower temperatures for sintering

3.Availability of fine line systems for printing

4.Excellent stability of shelf life

5.Prolonged screen residence times

6.Suitability for usage with a majority of plastics

7.High durability

8.Customized paste systems

Conclusion

Our services at Dynotech Instruments and technology pushes the processing capabilities of a number of industries in India beyond their present possibilities that is helping overcome the hurdles in the way of solar industry empowerment.

fiber laser heads

Comparing laser engraving machines: CO2 lasers Vs Fiber lasers

Laser engraving is a process that facilitates the vaporization of materials into fumes in order to engrave deep and permanent marks. The laser beam here acts like a chisel, engraving marks through the removal of layers from the surface of the material. For laser engraving, the laser hits certain localized areas for massive energy levels for engraving metal pieces that will be ultimately exposed to a number of surface or wear treatments. Metal engraving with aluminium and steel inclusive of both die-casting and anodized aluminium. The best feature of the process is the ability to engrave two-dimensional codes for high rates of readability even after the treatments that are done post-process.

 Fiber lasers

Fiber lasers with fiber laser heads utilize fiber optics as a gain medium. Other common gain mediums are mixtures of dyes, crystals, and gazes.

Fiber lasers utilize laser diodes as a source of energy. The wavelength of the light pumped is often altered due to rare earth elements doped in the gain medium.

 Advantages of fiber lasers

Highly adaptable to a number of metals like aluminium

Low or no maintenance required

Longer life cycles

High efficiency

Lesser requirement for heat management

CO2 lasers

C02 lasers with CO2 laser heads are an important part of the category of gas lasers. The source of energy for gas lasers is most commonly electric discharge, similar to the ones utilised for fluorescent lamps. Its main gain medium is a mixture of gases, composed of CO2.

Advantages of CO2 lasers

Highly adapted to breaking organic bonds of carbon-oxygen, which are mainly found in cardboard, paper, wood, ceramics, and plastics.

A highly established technology for welding and cutting metal plates.

Commonly employed in a number of industries such as the food, pharmaceutical and packaging industry.

The future trends in fiber lasers and CO2 lasers

Thanks to the scalability that fiber lasers offer, their efficiency and stability in terms of heat management, fiber laser technology can be increasingly used for a number of applications. Given the technological advancements in fiber lasers and the reduction in the prices of high-power lasers, there has been a notable increment in the CO2 systems that are retrofitted with fiber lasers for a variety of industrial applications, including laser welding and laser cutting in a number of manufacturing facilities. This trend is likely to be consistent for the years to come as well.

Conclusion

In addition to engraving and etching, Dynotech Instruments’ laser technologies can be employed for the purpose of marking identifiers and logos such as serial numbers and barcodes.

laser beam light

Laser cleaning: A holy grail for industrial cleaning applications

Laser cleaning is an environment-friendly process altogether. It can be utilized to effectively remove contaminants from the surface of metals. Given its accuracy and efficacy, it is being increasingly used for a wide range of applications, serving a number of industries. Laser cleaning is done using a pulsed-fiber laser over the traditional methods of cleaning that are highly tedious. Rust removal for example is highly time and manpower consuming.

Laser cleaning- A cost-effective solution

Manual removal of oxides on the other hand can be hazardous, given the involvement of direct contact with the chemical substances. Dealing with such problems in manufacturing and production can come with high costs, however, laser cleaning is changing this notion by being a highly cost-effective solution in itself for reducing the requirement of maintenance and high cleaning times. Laser ablation is a phenomenon that occurs when a coating or the layer of a material is removed employing a laser beam. This is the major process occurring behind all the applications of laser cleaning.

The ablation threshold

Laser rust removal from the surface of steel is an example of laser cleaning. There is an ablation threshold for all materials. Laser cleaning helps differentiate between materials while trying to remove an undesirable layer from a particular object. The selection of material to be removed becomes easier, given a considerably high difference of ablation threshold between materials. Additionally, fiber-laser cleaning systems can remove the undesired layers on the top of materials utilising two distinct methods.

A safe solution

The laser beam light can either be pulsed or a continuous light wave. The results using both types of fiber laser cleaning waves remain almost the same, however the speed of laser removal varies. Lasers utilise no solvents or chemicals which makes laser cleaning of surfaces a safe solution for industrial cleaning purposes. For example, utilisation of laser cleaning in nuclear power plants facilitates effective cleaning of pipes for large-scale projects. Laser cleaning is a no contact technique for cleaning serving the widest range of industrial purposes with the highest accuracy and efficacy.

In the present-day time, the most common applications of laser cleaning include;

1.Welding pre-treatment for the removal of rust and contaminants for a range of materials.

2.Welding post-treatment helps with the removal of oxides from materials such as stainless steel and aluminium.

3.Surface preparation using laser also helps maximise the level of paint adhesion.

Conclusion

Dynotech’s laser cleaning solutions help overcome a number of problems faced for cleaning applications in the industrial sector including automotive, med-tech, biomedical, consumer, solar industry and much more. 

laser beam

Effects of process parameters on laser weld quality

Prior to using a laser welding machine, it is important to verify a number of important parameters. Here are some important steps to ensure that the welding operations turn out to be a success. In a typical laser welding process, a number of welding process parameters affect the quality of the weld joint. Laser welding parameters include focal distance, pulse rate, shielding flow of gas, speed of welding, and laser power. The two major laser welding process parameters that affect the weld bead the most are speed of welding and laser power. The increase in welding speed however results in the decrease of the maximum shear load. Additionally, the increase in the speed of welding decreases the base metal area that is melted.

Energy adjustment

It is important that energy is adjusted appropriately for better adaptation of the power to the processes. This will also ultimately prevent wastage of energy.

Ensuring the accurate beam diameter

The diameter greatly affects the laser welding performance. It is therefore recommended to choose the laser beam with a diameter within a range of 0.2 to 2 mm.

 Check the frequency of the pulse

Pulse frequencies that are higher than normal result in pulse energies that are very low, making the laser welding process less efficient.

Waveform of laser pulses

It is recommended to alter the waveform according to the material, say a metal that you intend to weld. In case an inadequate waveform is utilised, about 60 to 98 percent of the laser will be lost, leading to failure of the welding operations.

Tensile strength and hardness

Tensile and hardness tests can be carried out in order to reveal the mechanical features of the weld bead. Both the welding speed and laser power have an effect on the maximal shear load of the laser weld. The increase in laser power ultimately increases the shear load.

Penetration depth

The depth of penetration is affected by the pulse duration and the peak power. If the peak power is considerably small, the melt pool is also going to be smaller.

Conclusion

Process parameters like welding speed and laser power are being consistently studied in order to determine effects on formation of pore and maximal weld-bead lap shear load. With Dynotech’s laser beam welding instruments, we have been proven to provide our services to and cater to a number of industries, be it the med-tech, automotive or the consumer industry for the best possible outcomes through precise and accurate processing and results.

laser micromachining systems

The working of laser welding: An important welding type

Comprehending the process of laser welding can be intense and at times confusing, especially if there is a recent acclimation to this important application of welding. Laser welding is increasingly becoming an important welding type and differs in a number of ways from typical welding. Effective use of laser welding technology requires the right know-how for production/manufacturing processes to righteously fall in place. In the past years, the most efficient lasers were only 10 percent as effective as today’s, with incredibly lower running costs. Laser welding is more like a tool in the tool-box. It is being used for a number of applications, be it the automotive, consumer, med-tech, or biomedical industry and much more. There are a ton of applications that have not utilised laser welding yet.

The process of laser welding and 3-D printing

In laser welding, two materials are joined together. For this purpose, the two sides of the material being abutted are melted. This melt further coalesces and forms a joint. Laser beam welding has been in usage since the past three decades, but it is only in the recent years that its usage has increased for a number of industrial applications. In fact, until recently, it has been used selectively and has been in a fierce competition with the traditional methods of welding. It is due to the modern-day additive methods of production such as 3-D printing of metals, laser welding is consistently gaining more importance. Laser beam welding is a highly automated process and can in no way be compared to the conventional, manually guided methods of welding. It can be therefore said that the joining process as part of laser welding is a highly safe production step. During the process of laser beam welding, the work piece is strongly clamped in a fixture.

Laser beam welding

The modern-day laser beam welding systems are well-equipped with a highly integrated measuring system that works independently to accurately check the dimensions of the component being manufactured. This makes laser-welding systems highly accurate, forming the basis for guaranteeing the best quality.

The advantages of laser welding can be as follows;

  1. High accuracy
  2. Torsion freedom
  3. High speed of joining
  4. Consistency in quality
  5. Wider material tolerance

Conclusion

In the past one decade, manufacturing has embraced laser welding more than ever, yielding results that have been highly efficient. The modern-day lasers are easy to maintain, modular, highly accurate and highly efficient. At Dynotech Instruments we facilitate the execution of top- priority industrial requirements with our laser welding technology and laser micromachining systems that successfully meets the GMP standards.

laser micromachining

Laser welding: An innovative tool for lean welding

Laser welding is increasingly becoming an important manufacturing technology for a number of production processes. Laser welding is a process that joins thermoplastics and metals together, utilising a laser beam to give form to a weld. Being the highly concentrated source of heat that it is, laser welding for thinner materials can be effectively carried out at high speeds (meters per minute). For thicker materials on the other end, deep and narrow welds can be produced between the parts that are square edged.

Mode of laser welding

Laser welding operates in two fundamentally distinct modes; keyhole and conduction-limited welding. The mode using which a laser beam will interact with the material that is being welded is dependent on the power density of the beam striking the material being laser welded. Laser welding is more commonly accomplished utilising a high-power density, using a keyhole mechanism. When the laser beam is focused on a smaller spot, enough power density is produced and the material in the path of the laser beam will vaporise in addition to melting. This happens prior to removal of significant quantities of heat through conduction. Furthermore, the coupling of a laser beam in the workpiece is drastically improved post the formation of a keyhole. Deep penetration type of welding can then be easily achieved, ultimately resulting in welds that have a high depth to width ratio.

A typical laser welding system

Given the action of surface tension, molten material present at the leading edge finally cools down and solidifies to form the weld. The scope and potential for laser welding is immense. Scientists are making consistent efforts to further research and test this novel welding technology for achieving greater compatibility to suffice the advancements in the forthcoming years. A typical laser welding system comprises a motorized guide and laser optics. In a majority of cases, semi-finished products to be welded must be clamped firmly for enabling precise joining. A distinction has therefore been developed between a stationary laser welding system and a mobile laser welding system.

Safe laser welding technology- The future of laser welding

Safer technology is often neglected but is crucial for the process of laser welding. In addition to advanced welding technology, such as virtual reality and laser welding. The field of laser welding has its eyes on the potential future of safe welding technology. This laser welding technology, if implemented correctly, utilising lean practices in the laser welding operations can facilitate expansion in terms of capacity and improvised production/manufacturing processes.

Conclusion

Dynotech Instruments represent leading laser welding and laser micromachining manufacturers from across the world and is bringing new, safe, technology to India. Our variety of divisions cover a wide range of applications including photonics, nanotechnology and solar lasers

Latest Trend in Additive Manufacturing

3D printing or additive manufacturing is a process of making 3 dimensional solid objects from a digital file/model, typically by laying down many consecutive thin layers of a material.

Introducing our principal Aconity3D GmbH, which specializes in the design and distribution of modular machine tools for powder bed based laser beam melting of metals. The easy-access machines cover enables quick material change with simultaneous access to all important technical components.

The system offers access to all relevant process parameters and can be modularly equipped with a preheating device, process monitoring or modifies laser configuration for maximum user benefit.

The key advantages of Aconity3D printing machines are as follows:-

· Full-overlap multi-laser configuration master/slave operation for selective laser-preheating.

· High temperature preheating, inline process monitoring

· Multi-material option

· Flexibility, suited for all applications with remote machine control via Aconity STUDIO etc.

The job shop offers printing on a variety of metals and support the innovative material research which consists of High thermal and electrical conductivity with high mechanical strength at low specific density, high mechanical strength and corrosive resistance, biocompatibility and low thermal conductivity.

Conclusion:-

It is generally accepted that 3D printing will be revolutionary force in manufacturing.

Process of Laser Plastic Welding

Laser beam welding is a welding technique used to join pieces of metal or thermoplastics through the use of a laser. The technique of laser welding is considered a high energy density beam process, and can be used to join thick matter with the welds.

With many years of creativity and innovations, industries started getting a good and longtime solutions for laser plastics welding. Laser plastic welding can be defined as: “A method of joining two plastics by consecutive transmission and absorption of high energy laser”. The technique is ideal when plastic parts are to be joined together reliable. The technique covers a wide area of industry such as electronics and telecommunication, space & defence, automotive, medtech, etc., with a whole lot of advantages in different sectors.

The principle of Laser welding is that a part that is transparent for the laser light is placed on top of a part that absorbs the laser light. The beam is transmitted through the top part and hits the lower part, where the energy is absorbed, resulting in a temperature increase, and local melting of the plastic occurs. The thermal expansion of laser causes the molten plastic from the lower part to contact the top part, causing additional melting in the top plate. To keep the parts in place only a small amount of compressive force is required. When sufficient melt is formed, the two molten spots bind together to form a joint, which solidifies after cooling.

The laser welding process imposes a number of requirements on the materials used. The most critical ones are the transparency of the top part. The absorbing part is crucial for melt formation and the absorbance of this part should be optimized for generating a melt pool that result in sufficient weld strength.

The key advantages of Laser Plastic Welding are as follows:-

· Ability to hold tighter tolerances in the joining process

· Accurate control of welding area

· No damage to surrounding materials

· Joining of 3D and complex shapes

· Ability to miniaturize designs

Conclusion:-

If there is a need to get rid of the quality and miniature design problems by avoiding damage to sensitive electronics than laser plastic welding is the right choice for the design!