With the development of science and technology, micro-nano technology has been widely used in various fields, such as medical treatment, environmental protection, laboratory, chemical industry, semiconductor, industrial automation, etc. Precision micro components refer to electronic, mechanical, optical and other components with micron or nano scale, which can realize efficient, precise and sensitive functions, such as sensing, control, driving, communication, etc. The manufacture and connection of precision micro components is an important part of micro-nano technology, among which laser welding machine is an efficient and precise welding method that can be used for the connection and packaging of tiny parts. We will introduce the working principle, advantages and application range of precision micro-component laser welding.

1. Working principle of laser welding of precision micro components

Laser welding is a high-efficiency and precise welding method that uses a high-energy-density laser beam as a heat source, and can be used for welding tiny parts. Laser welding can be realized by continuous or pulsed laser beam, and its principle can be divided into heat conduction welding and laser deep penetration welding.

Heat conduction welding means that when the laser beam power density is less than 10^4 W/cm^2, the metal surface absorbs the laser energy to form a molten pool, and the energy exchange between the inside of the molten pool and the surrounding metal is mainly through heat conduction, forming a shallow and wide joint. of the weld.

Laser deep penetration welding means that when the power density of the laser beam is greater than 10^6 W/cm^2, the metal surface is heated and concaved into "cavities", forming a high-temperature and high-pressure plasma column, and at the same time generating a strong reverse air flow, which will The molten metal pushes down, creating a deep, narrow weld.

2. Advantages of laser welding of precision micro components

Compared with traditional welding (such as resistance welding, arc welding, etc.), laser welding of precision micro components has the following advantages:

a. The quality of the weld is high, the deformation is small, and no follow-up treatment is required. The heat-affected zone of laser welding is small, the cooling speed is fast, the surface of the weld seam is smooth, there are no defects such as pores and cracks, and the welding strength is high. Laser welding has a small amount of deformation, and generally does not require filling materials or auxiliary gases, nor does it require post-processing such as grinding and polishing.

b.The welding process is highly automated and easy to operate. Laser welding equipment can be controlled by a computer to achieve precise adjustment and positioning of the laser beam to meet complex welding requirements. Laser welding does not need to touch the parts to be welded, and the operation is flexible and convenient. It can be used in conjunction with robots or numerical control systems to realize automated production.

c.Fast welding speed, high efficiency and energy saving. The energy density of laser welding is high, the melting time is short, and the welding speed is fast, generally up to several meters per minute. The energy utilization rate of laser welding is high, generally up to 30%, saving more than 50% of energy compared with traditional welding. The processing range of laser welding is wide, and multiple stations can be welded at the same time to improve production efficiency.

d.It can weld different materials or dissimilar materials. Laser welding can weld various metal or non-metal materials, such as steel, aluminum, copper, nickel, titanium, etc. Laser welding can also weld dissimilar materials with different physical or chemical properties, such as steel and copper, titanium and nickel, etc., to achieve material combinations that are difficult to connect by traditional methods.

e.It can weld inaccessible parts. The laser beam can be transmitted and guided by optical fiber or reflector, and can weld hidden or complicated parts, such as the inner wall of the pipe, the engine of the car, etc. Laser beams can also weld in special environments such as vacuum, inert gas or underwater.

f.Micron-level precision welding can be realized. The laser beam has good focusing and directivity, and can form extremely fine spots to achieve micron-level or even nano-level precision machining.

3. Application range of precision micro-component laser welding

Due to its high efficiency, precision, reliability, and environmental protection, laser welding of precision micro components has been widely used in various fields, such as:

a.Laser welding of electronic components. Electronic components refer to tiny components with electronic functions or electronic connection functions, such as integrated circuits, capacitors, resistors, crystal oscillators, transformers, switches, sockets, etc. Laser welding of electronic components is mainly used to realize the connection or packaging between components or between components and substrates. Laser welding can achieve micron-level or even nano-level precision processing, ensuring that the functions and performance of components will not be lost or affected. At the same time, laser welding can also achieve lead-free or low-lead welding, which meets environmental protection requirements.

b.Laser welding of medical devices. Medical devices refer to instruments, equipment, tools, etc. used for medical diagnosis, treatment, nursing, etc., such as cardiac pacemakers, artificial joints, dental brackets, surgical knives, etc. Laser welding of medical devices is mainly used to achieve internal or external connections or packaging of devices. Laser welding can achieve high-strength, high-density, seamless welding to ensure the safety and durability of the device. At the same time, laser welding can also achieve non-toxic or low-toxic welding, which meets hygienic requirements.

c.Micro Electro Mechanical System (MEMS) laser welding. Micro Electro Mechanical System (MEMS) refers to a system that integrates micro sensors, actuators, controllers, etc. A system on a tiny chip with multiple functions and applications such as pressure sensors, accelerometers, gyroscopes, micromirrors, micropumps, etc. The packaging and connection of MEMS is an important link in its manufacturing process, and it is necessary to ensure the reliability, stability and performance of the system.

In conclusion, laser welding of precision micro-components is an efficient, precise, reliable, and environmentally friendly method of joining micro-components. It has the advantages of high energy utilization, high welding quality, low heat-affected zone, low residual stress and deformation, etc. Welding with dissimilar materials to meet the diverse needs of precision micro components. Laser welding of precision micro components is widely used in various fields, such as electronic components, medical equipment, micro-electromechanical systems, etc., providing strong technical support for the development of these fields. Precision micro-component laser welding, as an advanced micro-component connection technology, has broad development prospects and application potential, and is worthy of further exploration and promotion.