Industry Background
In recent years, as electronic components have continued to miniaturize, the demand for high precision, high density, and high reliability in products has significantly increased. Manufacturing engineers are particularly focused on how to achieve effective micro-connection processing, maintain stability and reliability during the process, and implement smart identification and tracking of product information.
main components of a VCM motor
The term VCM stands for Voice Coil Motor, a type of motor whose working principle is similar to that of a speaker. Currently, VCMs are commonly used in the driving motors of smartphone zoom lenses and hard drive actuator arms. With the rapid development of the 3C electronics industry, customers have higher demands for the cameras in electronic products. As the products become more sophisticated, the materials used are becoming increasingly thinner. Camera modules have evolved from single-camera setups to dual-camera systems, and more recently, to the now-mainstream triple-camera configurations. This trend indicates a growing demand for VCM motors.
Current Technology
The laser welding process for VCM motors mainly includes Spring-to-Base laser welding and Yoke-to-Base laser welding.
For Spring-to-Base connections, YAG or QCW fiber millisecond pulse lasers have traditionally been used for spot welding. However, these methods have significant drawbacks, including poor stability, large heat-affected zones, and severe burning of adhesives. Moreover, the resulting welds have low pull strength, poor conductivity, and cannot be visually inspected for quality.
QCW fiber single-pulse spot welding
For Yoke-to-Base connections, the traditional method has been adhesive bonding, which not only requires consumables but also has low efficiency. Additionally, this method suffers from inconsistent pull strength, adhesive aging, and the need for secondary cleaning.
Yoke and Base adhesive bonding
New Laser Welding Technology
Laser micro-welding refers to a welding technique that achieves dimensions smaller than 100μm in at least one dimension using lasers. As an alternative to other micro-connection techniques, laser micro-welding offers several advantages, including high connection strength, precision, flexibility, non-contact operation, minimal heat-affected zones, minimal thermal distortion, fewer restrictions on workpiece shape, and single-step operation.
Process Principle
Laser micro-welding primarily uses low-energy, high-frequency pulse lasers (with energy levels in the mJ range and effective working pulse widths in the ns range). The laser is directed onto the material’s surface through an optical path, where the laser intensity exceeds a certain threshold and is absorbed by the material. Under the influence of high-frequency pulses, the material melts, forming a “keyhole.” The laser refracts and reflects within the keyhole, continuously melting the material to form a weld. This method creates patterned welds, where the laser follows a pattern trajectory to form the weld. Compared to traditional laser welding, it has the following advantages:
- The welding area and shape are controllable, making it suitable for various irregular welding regions.
- It is particularly well-suited for precision welding of thin materials.
- The heat input range is large and controllable, making it ideal for welding dissimilar materials.
- The consistency of welding high-reflective materials is excellent.
Patterned weld point formation in micro-welding
Weld path
Stainless steel welding with aluminum alloy
Recommended VCM Laser Welding Equipment
For VCM motor laser welding, the Han’s Laser SFM70E nanosecond laser welding system offers an efficient connection solution that meets users’ precision micro-machining needs.
System Overview
The system’s laser features a MOPA structure with a nanosecond-level pulse width and a maximum output frequency of up to 1000kHz. The peak power can reach 13kW. This laser welding machine supports both pulse and CW modes with a wide selection of waveforms, allowing for precise control of heat input. The SFM70E excels in welding thin materials, high-reflective materials (such as copper alloys, aluminum alloys, and gold), and dissimilar metals. Welded products have consistent and uniform weld points with improved tensile and shear strength compared to YAG and millisecond fiber lasers.
Spring-to-Base Welding Results
Materials
0.03mm copper alloy + 0.1mm gold-plated stainless steel
Requirements
The weld points must be aesthetically pleasing with no spatter, have a pull strength greater than 300g, and avoid burning the plastic on the rivet post, sidewall, and backside positioning holes. The weld quality must be visually inspectable, and defective products should be identifiable and destructed with a matrix display.
Process Comparison
Traditional QCW fiber and YAG spot welding methods fail to allow visual inspection of weld quality, and the welding process is unstable, often burning the adhesive. Additionally, the pull strength test results fluctuate significantly. With the new SFM70E process, the welding process is stable and reliable, effectively preventing adhesive burning. The weld quality is visually inspectable, and the post-weld pull strength is stable, exceeding 300g.
Single-lens camera A
Single-lens camera B
Dual-lens camera
Yoke-to-Base Welding Results
Materials
0.15mm high-phosphorus nickel stainless steel + 0.1mm gold-plated stainless steel
Requirements
No yellowing or blackening is allowed on the surface, with a pull strength greater than 3kgf, and no burning of the sidewall and backside plastic. The weld quality must be visually inspectable.
Process Comparison
Traditional QCW fiber and YAG spot welding methods are unstable and prone to burning the adhesive. The post-weld pull strength test results fluctuate significantly, with a maximum pull strength of only 2.0kgf. The new SFM70E process ensures a stable and reliable welding process, effectively preventing adhesive burning. The post-weld pull strength is stable, exceeding 3kgf.
Housing welding A
Housing welding B
Han’s Laser has quickly developed and refined this new laser welding process specifically for VCM motor welding, gaining widespread recognition and large-scale adoption by major VCM motor manufacturers. This has solidified Han’s Laser’s leading position in the VCM motor laser welding field. Looking ahead, Han’s Laser Precision Welding will continue to drive innovation and independent development, promoting the application of advanced technological processes to better serve users and create new high grounds for high-end and intelligent manufacturing applications.