Laser machining apparatus

Abstract

A laser machining apparatus comprising a deflector for changing the direction of the laser beam emitted from a laser oscillator and a condenser lens for refracting the laser beam incident thereon from the deflector and forming an image on a work as the machining object, wherein lens position adjustment means capable of changing the relative positions of a plurality of lenses comprising the condenser lens by a condenser lens temperature is assembled into the apparatus, and this lens position adjustment means changes the relative positions of a plurality of lenses by the condenser lens temperature in such a manner as to offset the change of the refractive index of the lenses with temperature.

Description

technical field [0001] The present invention relates to a laser processing device, in particular to a laser processing device for drilling, cutting, and marking resin materials such as printed circuit boards and semiconductor chips (chips) or ceramic materials. Background technique [0002] As a laser processing device for performing drilling, cutting, marking, etc., known conventional Figure 46 structure shown. [0003] This laser processing apparatus includes, as an optical system: a laser oscillator 1 as a source of laser light L, a collimator lens (collimate lens) 2 for adjusting the divergence angle of the laser light, and aligning the direction of the laser light L in accordance with the rotation angle. Y-axis galvanomirror (galvanomirror) 3 and X-axis galvanomirror 4 deflected in any direction, and Y-axis galvano-scanner that adjusts the rotation angles of Y-axis galvanomirror 3 and X-axis galvanomirror 4 according to the processing program (galvano scanner) 5, an X...

AI Technical Summary

Problems solved by technology

[0024] Because the conventional laser processing device has the above-mentioned structure, the temperature of the focusing lens 7 fluctuates through the surrounding temperature or the heat generated by the laser processing device itself, which causes the problem that the processing position shifts in approximately proportion to the temperature fluctuation. There is a phenomenon that the processing position deviates by 10-15 μm per 1°C, which becomes a problem of processing failure.

[0025] The deviation of the processing position caused by the aberration of the focus lens 7 can be compensated by the focus lens aberration correction of the above-mentioned coordinate transformation, but when the temperature of the focus lens 7 changes during the aberration correction, the focus lens 7 The optical temporal change, when the temperature rises, such as Figure 52 As shown, the disadvantages of processing that cause the overall shrinkage of the grid points that are actually processed

[0026] In addition, the temperature fluctuation of the focus lens 6 not only causes a shift in the processing position, but also causes a change in the focal length, and the focal point is separated from the working W surface, thereby causing a problem of poor processing position.

[0027] like Figure 53 As shown, when the temperature of the focus lens 7 is T, the laser beam incident on the focus lens 7 is focused by the laser beam La, and the focus point Pa is on the surface of the workpiece W, which can be processed well, but the temperature of the focus lens 7 is only In the case of fluctuations in δT, laser beams at the same incident angle are focused by the laser beam Lb, so the processing position deviates by δX, and the height of the focus point Pb also increases by δf.

[0028] Such a deviation of the processing position cannot be recognized unless the accuracy is checked after processing, and the processing continues in a state where a large number of position deviations are caused, thereby causing a problem of mass production of poorly processed substrates.

[0029] In addition, when the focus lens aberration correction is performed frequently, the deviation of the processing position can be eliminated, but in actual automatic processing, when performing the correction of the focus lens, the operation must be stopped, which reduces productivity.

[0030] Since there is no method of automatically performing deviation detection of the focus distance, the focus distance must be calculated in advance by the operator in actual processing, and if it is constantly changing, there is no effective measure for the change.

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