Micro Stepper Motor

Micromotors are key actuators in micro-electromechanical systems. With the in-depth research of electronic technology and precision machining technology, micromotors are developing in the direction of miniaturization, multifunctionality and modularization. At the same time, micromotor materials are not limited to silicon commonly used in microelectronics technology, but also include ceramics, metals, composite materials, etc. How to reliably assemble these tiny parts with different materials and properties into complete micromotor products is an important process in micromotor manufacturing. In addition to the necessary assembly robots and operators, connection technology is the core part of the entire assembly process.

Gluing is a process that uses adhesives to connect parts without melting the surface of the parts. Compared with micro-connection methods such as micro-welding and solid-phase bonding, micro-bonding has the following advantages: ① Wide range of applications, able to bond parts of the same or different materials; ② Low curing temperature, which can avoid the effects of high temperature environment on micro-parts such as dimensional changes, uneven stress and even performance damage; ③ High curing strength and uniform stress distribution; ④ Easy to achieve additional functions such as sealing, conduction or insulation.

Micro Stepper Motor

The basic structure of a micro-stepping motor is shown in Figure 1. The motor is mainly composed of a substrate, a mover, and a linear guide. The substrate also acts as a stator, with magnetic poles, stator teeth, coils, and control circuits on its surface; the mover is located above the stator, with mover teeth on its lower surface; the guide acts as a linear bearing to keep the mover in place. There is a sealing housing above the guide and mover, and the mover is separated from the surrounding components by an air gap. The design size of the substrate is 10mm × 4mm × 1mm, and the size of the guide is 8mm × 1mm × 1mm. The substrate and the guide are made of single crystal silicon material and assembled together by gluing.

The requirements for the quality of adhesive assembly are as follows: ① The two guide rails remain parallel in the direction of the mover's movement; ② Due to the presence of adhesive, the height of the guide rail does not increase by more than 10μm; ③ The guide rail remains parallel to the surface of the substrate; ④ The surface of the functional area is not contaminated by the adhesive. For this purpose, a bonding area is divided on the surface of the substrate for dispensing, and the size of the bonding area is 900μm × 900μm.