Laser Treatment System EM-250A

The system is designed for silicon wafer scribing, through (via) cutting according to a preset contour and drilling  holes in substrates of silicon and other materials used in microelectronics. Thickness range of processed substrates is up to 2 mm.

The substrates are processed by automatic linear step motor positioning in horizontal plane along X,Y axis relative to the laser beam. Angular orientation of the substrate is done by rotation of the worktable in horizontal plane (angle j). Motion of the laser system’s lens in the vertical direction (Z) keeps laser beam focus position. The linear step motor with feedback ensures high precision processing with linear travel speed up to 600 mm/s at speed irregularity up to 5% max. The use of linear step motor on air bearing excludes friction and guarantees its long service life.

A solid-state YAG  laser, model RL-30Q, with Q-switch is used in the system as a laser source. Service life of laser heat is at least 10000 hours. Service life of pump lamp is at least 400 hours.

Laser power supply and cooling unit contains the system for selection and stabilisation of cooling water temperature. This allows to maintain the average power of laser radiation at high stability level. Interlocks of minimal flow of the cooling water and of its max temperature allows to enhance  reliability and service life of the laser.

The Laser Treatment System is controlled by IBM PC. Working program is made both with the use of own graphics editor and AUTOCAD editor. The computer allows to automatically select an optimum travel algorithm and the laser Q-switch control depending on the thickness of the processed material, its shape and contour of laser processing.

Laser

*Type Q-switched, Nd:YAG, Lamp pump *Operating mode TEM00, circular and linear polarisation *Wave Length 1064 nm *Average Power 25 Watt @ 25kHz *Pulse Width ~ 85 ns @ 3 kHz Q-Switch Frequency 3-50 kHz

Positioning System

Field Size 150 х 150 mm Precision 5 µm Cut width (silicon scribing) up to 35 µm Resolution 2 µm Speed of linear movement up to 600 mm/s Angle of turn 360? *Power requirements 380/230 V, 50 Hz, 6.5 kW *Overall dimensions 1870x840x1300 mm *Weight 600 kg Note: - features marked * are reference data.

TV-channel enables receipt on SVGA monitor “live“ videopicture of the object for orientation of the workpiece followed by inspection of the quality of processing.

The control system is based on PC and provides the following:

• control to all drives in automatic processing mode and orientation mode;
• storage and automatic selection of  treatment modes according to preset process  parameters;
• editing of layout to be processed in AUTOCAD 14 system as DXF file;
• editing of scribing layout within its own program;
• inspection of average laser power with display of pictogram on computer screen;
• control to R.F. driver;
• display on computer screen of TV-picture of surface of the substrate during its angular and position orientation;
• display on TV-screen of the on-line information (absolute and relative coordinates of the stage, process steps, prompting of operations sequence, treatment time, error warning, etc.);
• execution of special debugging operations (search for beam focus, its alignment with Zero of coordinate system, scaling of coordinate system, etc.);
• creation and storage of the library of programs of operations including type of operation (via cutting, scribing), layout pattern and list of process parameters;
• power-units diagnostics.
  

• Ambient temperature: 22°C±5°C
• Relative humidity: not more than 85%
• Power requirements: 3-phase 4-wire with neutral 380/220 VAC, (50±2%) Hz, impulse noises protected.
  Maximum voltage deviation from nominal: ±10 %. For power supply a separate electric power line must be used. High-voltage and switching equipment like welding devices , electrical ovens, metal-cutting machines, etc. must not be connected to the distribution board of this line.
• Compressed air to be supplied to the system under pressure 0.5-0.6 Mpa (5-6 kgf/cm²). Compressed air consumption is 1.5 m³/h. Compressed air shall be supplied by means of a flexible PVC pipe with outer diameter 10 mm and wall thickness 1.5 mm. The temperature of the air to be supplied to the system shall not deviate from the room temperature more than 5°C.
• The system must be connected to the vacuum with residual pressure (3.4...4)*10⁴ Pa, the connection shall be supplied by means of a flexible PVC pipe with inner diameter 6 mm.
• The system must be connected to exhaust ventilation line with the pressure not less than 10 kPa (or to a vacuum cleaner with power at least 1 kW).
  The system should be connected to exhaust ventilation by means of flexible corrugated tube with inside diameter 34 mm and outside diameter 43mm (supplied).
• Water under pressure 0.1 - 0.2 Mpa (1-2 kgf/cm²) with flow rate not less than 10 l/min and temperature not more than 18°C with free drain of waste water.
• The inner laser cooling system is filled with distilled water (10 liters).
• Grounding.
• Floor space 10 m².