Voice coil motor (VCM) belongs to the linear DC motor, has a compact size, simple structure and other characteristics, become the most mainstream products of the mobile terminal camera, its working principle is the electromagnetic thrust generated by the energized coil under the action of the permanent magnetic field and the reaction force generated by the front and rear reeds deformation interaction, the formation of a combined force to drive the lens group back and forth to move, to play the role of the focus, to achieve the purpose of the image is clear. The principle of voice coil motor was originally used to produce vibration sound in loudspeakers, so it is named voice coil motor.
Voice coil motor industry applications
The upstream industry of voice coil motor is mainly the reed, magnet, coil and other basic materials and accessories production industry, and the downstream industry is the smart phone, notebook/tablet computer, security/conference camera system, car electronics, aerialand other electronic equipment production industry. Among the voice coil motor in the downstream industry market smart phones, tablet PCs and other applications are particularly significant.
According to market research data found that China's smartphone industry chain is developing at a high speed, domestic smartphones are increasing their market share in the world, and China has become the world's largest cell phone manufacturing and production base, which provides a huge space for the development of the domestic VCM enterprises.In the year of 2021, the shipment of smartphones was 343 million, an increase of 15.9% year-on-year, accounting for 97.7% of the cell phone shipments in the same period.
At present, the global VCM industry presents an oligopoly pattern, mainly distributed in Japan, South Korea, China and other regions. Among them, Japanese companies TDK, Alps (ALPS) and Mitsumi (Mitsumi) occupy more than 40% of the global market share of voice coil motors and hold advanced technology and manufacturing capabilities, followed by Chinese and South Korean companies such as Haosawa Electronics, SEMCO, Jahwa, and so on.
In the field of cell phone camera module manufacturing, not only can save costs and meet the current market demand for high-precision cell phone camera precision welding process, has been selected by the major camera electronics manufacturers.
Camera VCM laser welding process
For the camera module and module in the voice coil motor laser welding, welding materials are mainly laser welding special welding paste (spot welding paste laser welding) and lead-free solder balls (laser spray welding), of which the choice of solder paste is particularly important, the need for special laser solder paste. If you use ordinary solder paste, there will be burst tin, solder bead splatter and other defects, seriously affecting the performance of laser welding. The current cell phone camera to be welded to the reserved position is very small, small enough to reserve only 0.59mm gap solder, or even smaller. For the camera welding, it has now developed from manual welding to laser welding. Laser welding special solder paste, due to the use of special anti-spatter solder paste material, can ensure that the solder paste in the laser rapid welding process does not splash (as fast as 0.3 seconds), and can be instantly agglomerated to complete the laser welding process.
Laser welding machine in the process of welding cell phone camera does not require tool contact, avoiding tool contact with the device surface damage caused by the device surface, processing accuracy is higher. It is a new type of microelectronic packaging and interconnection technology, which can be perfectly applied to the processing of cell phone anti-shaking camera. Therefore, the laser welding machine has a very broad application prospect in the production of cell phone camera core devices.
For example, the laser welding process of the bracket in the cell phone camera module, a smart phone camera bracket is only the size of a fingernail cap, but there are a variety of parts and components, and the parts material is very thin and light, which brings great challenges to the welding process, the traditional rivets, glue bonding and so on can no longer meet the welding needs.
Laser welding process through the high-energy beam precision focus and rapid welding, weld seam flat and perfect, solid welding, improve the overall electrical conductivity, and will not damage the other surrounding workpiece.
