What is a miniature XY table?

XY tables are mechanical or electromechanical devices which are used for the purpose of range enhancement, motion control, and position control. The workpiece whose position needs to be adjusted is mounted on top of the XY table and the table can then advance in a controlled and measured way along the XY horizontal plane.

XY tables come in a vast variety of shapes, forms, features, and capacities. Various kinds of XY tables are employed in different types of industries for different types of applications. One of the types of an XY table is the miniature XY table. Miniature XY tables have a very small size and compact form factor. Out of all the XY table variants, these miniature tables are perhaps the most accurate and precise ones. These tables are specifically designed for the handling and assembly of miniature objects and are used for very intricate work.

Miniature XY tables are also known as XY translators or XY positioners. The reason for this naming is the translational or linear motion which is used to achieve accurate positioning of the workpiece. XY miniature tables are particularly used in applications where the work area and the loading weight are very small, and very precise and accurate motion is required.

Figure 1: https://www.thorlabs.com/images/TabImages/xy_miniature_stage_A1-780.jpg

Construction of the miniature XY table

The construction of a miniature XY table is more complex as compared to a regular size XY table. The reason for this is that the miniature table assembly requires very small parts and motors. In addition to that, the miniature table is required to provide very high accuracy, resolution, and acceleration as compared to a regular XY table.

Often times advanced mechanical and electrical engineering techniques are applied to keep the size, weight and form factor of the miniature table to a minimum. For example, often these motors have a uni-body construction which means that both the linear sliding bases of the table are fabricated from a single metal block. Another example is the use of specialized piezoelectric servo motors which provide a greater degree of stability, speed, and accuracy.

Like XY tables, miniature XY tables also come in two major versions.

  • Manually operated miniature XY tables
  • Automatic motor operated miniature XY tables

The miniature XY tables are purely mechanical devices which are advanced along the 2 axes by means of small knobs provided for each linear sliding base. This type of miniature table does not have any sensors or electronic controllers and are operated by an operator.

The motorized version of the miniature XY table employs specialized servo and stepper motors which are designed for maximum performance, stability, precision, and accuracy. In addition to that, these motors also have sensors such as optical encoders, home sensors, and limit sensors. Optical encoders are used for extremely precise positioning and provide accurate feedback to the servo/stepper motors. The resolution of the optical encoder is often programmable and can be adjusted to as low as 0.01 micrometer for some models. Reflective types of optical home/limit sensors are used to detect the dead ends and limits of the table. The home/limit sensors are also adjustable.

The motorized miniature XY tables can also be connected to a computer via RS-232, RS-485 or USB 2.0 ports. A motion path plan can be created in the relevant computer program and provided to the miniature table’s electronic control system. This control system will then execute the path plan and the desired positioning of the workpiece will be achieved automatically.

The mounting surface of the miniature tables have holes drilled into them which can be used for mounting the tools and jobs by means of small screws or bolts. However, different applications require different types of mounting surfaces and holders, therefore various types of adapter plates are also available from the manufacturers of these devices.

For the construction of regular XY tables stainless steel and cast iron are commonly used. However, to keep the device weight to the minimum, aviation grade aluminum is used for the construction of miniature XY tables.

Since these miniature tables are widely used for the assembling and testing of electronics, PCBs, semiconductor devices and biomedical electronics, hence to mitigate the effects of electronic interference and static charges, the frame of the miniature tables are also coated with low ESD materials. ESD stands for electrostatic discharge.

Figure 2: https://www.thorlabs.com/images/TabImages/T12XY_dwg_2_large.gif

Applications of XY miniature tables

The miniature XY tables are very commonly used in industrial and research facilities. Some of the major application areas of XY miniature tables are fiber optics handling, electronics assembly and testing, optomechanical alignment, semiconductor applications, laser applications, and biomedical applications. These applications require very precise and accurate positioning with very high performance and the miniature XY tables serve that purpose well.

Figure 3: https://www.ebay.com/itm/Edmund-Optics-Miniature-XY-Stage-w-Platform-Accessories-/201772874819