KR100584838B1 - Method of calibrating of via hole laser drilling system - Google Patents

Abstract

The present invention discloses a method of calibrating a laser drilling system. The calibration method of the disclosed laser drilling system, the calibration method of the laser drilling system, the calibration method of a laser drilling system having a master head and a slave head, comprising the steps of moving the calibration plate below the master head and slave head; Laser processing the array points with the plate to the master head, and wherein the first spacing of the slave head from the master head is determined by the slave head from the master head when processing the substrate to be machined. If different from the two intervals, moving the slave head linearly to maintain the distance of the slave head from the master head as the second interval, and the plate by the distance obtained by subtracting the first interval from the second interval; Moving the slave head to the plate Laser processing the array points, and sequentially observing the processed array points to calculate an offset at each array point.

Description

Calibration method of laser drilling system {Method of calibrating of via hole laser drilling system}

1 is a view showing a schematic configuration of a general dual head laser drilling system.

2 is a flowchart illustrating a laser correction method of a conventional laser dual head.

3 is a diagram illustrating an array of acrylic plates and processing grooves.

4 is a flowchart of a calibration method of the laser drilling system according to the first embodiment of the present invention.

5 is a view for explaining a processing region of the acrylic plate used in the present invention.

6 is a flowchart of a calibration method of the laser drilling system according to the second embodiment of the present invention.

FIG. 7 is a diagram illustrating machining 144 array points into one machining area.

The present invention relates to a method for correcting a laser drilling system, and more particularly, to a method for correcting a laser processing position of a dual head laser drilling system having a master head and a slave head for processing via holes.

A laser drilling system is a device for drilling small holes and special via holes using laser light for connecting between layers in an electronic device of a multilayer board. In order to process the via hole corresponding to the interlayer connection passage of the multi-layer PCB (Printed Circuit Board), a mechanical drill was conventionally used. Due to the limitation of the laser processing method has been used as an alternative.

1 is a view showing a schematic configuration of a general dual head laser drilling system.

Referring to FIG. 1, the laser beam oscillated from the laser oscillator 10 is incident to the half mirror 16, which is a beam splitter, through the collimator 12 and the aperture 14. About 50% of the incident laser beam incident on the half mirror 16 is reflected and enters the master laser head 30, and the remaining laser beam passes through the half mirror 16 and is reflected by the reflection mirror 18 to be the slave laser head. Enter 40.

Each laser beam entering the master laser head 30 and the slave laser head 40 is controlled by the galvano scanners 31 and 41, respectively, and then through the f-theta lenses 35 and 45 through the PCB substrate. A via hole is formed in 50. The galvano scanners 31 and 41 are composed of x mirrors 32 and 42 and y mirrors 33 and 43, each of which is controlled at an angle by a controller (not shown). Reference numeral 60 denotes an X-Y stage, which moves the substrate on a plane, and reference numeral 70 denotes a linear movement device of the slave head.

In order to increase the via hole processing speed of the substrate 50, the laser light from one laser oscillator 10 is divided and laser processed by two heads 30 and 40 simultaneously. At this time, the laser processing area of the substrate 50 is divided into two and processed into the respective heads 30 and 40.

The size of the substrate 50 may vary for each processed lot. Therefore, when the size of the substrate 50 is changed, the position of the slave head 40 is moved in the direction of the arrow by the linear transfer device 70 to divide and process the via hole processing region of the substrate 50.

On the other hand, in order to improve the accuracy of laser processing, the processing error of each head 30 and 40 is measured.

2 is a flowchart illustrating a laser correction method of a conventional laser dual head.

Referring to FIG. 2, first, the length of the substrate to be laser processed is divided into two, and the slave head 40 is moved using the linear transfer device 70 while the master head 30 is fixed (step 101). ). Movement of the slave head 40 requires calibration of the master head 30 and the slave head 40 due to shaking.

An acrylic plate (not shown) is then placed under the master head 30 and the slave head 40 with the XY stage 60, and then each array has some array points, such as 9 × 9, on the acrylic plate. The array points are processed (step 102). In this case, a groove may be formed in the acrylic plate by making the acrylic plate thicker than the PCB substrate 50 for drilling.

Subsequently, the position of each groove is detected while the vision camera (not shown) is sequentially moved to the position corresponding to each processing groove (step 103). The control unit not shown measures the offset value between the measured position of the groove and the target position of the groove at the moving position of the stage 60 to correct the machining error at the detection position of the groove.

3 is a diagram illustrating an array of acrylic plates and processing grooves.

Acrylic plate 80 is 500 mm x 80 mm in size and processes 9 x 9 array points to calibrate one head. When machining 9 x 9 array points once, the distance between the grooves is 6 mm and the groove size is 100 μm, the pure area occupied by one array point is 6 mm x 8 + 100 μm, approximately 50 mm. x 50 mm, exactly 48.1 mm x 48.1 mm. The acrylic plate 80 may be divided into two parts, the machining area 81 of the master head and the machining area 82 of the slave head.

However, when correcting by the conventional method, the area processed by the master head 30 can be repeatedly used by utilizing the space between the holes, but the machining array points in the area processed by the slave head 40 are slave heads. As the position 40 is separated from the master head 30 is changed, the position is not constant. Therefore, the number of times of repeatedly using one acrylic plate 80 is limited by overlapping the machining positions in the region 82 to be processed by the slave head 40. This problem leads to an increase in the cost of the acrylic plate 80 and an increase in the time for changing the acrylic plate 80, thereby lowering the productivity of using the dual head drilling system. In particular, as the acrylic plate 80 is corrected, the holes processed by the slave head 40 overlap, leading to calibration failure, thus, waste of calibration time.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a method of calibrating a laser drilling system using an acrylic plate stably and repeatedly in a dual head laser drilling system.

In order to achieve the above object, the laser drilling system calibration method of the present invention, in the calibration method of the laser drilling system having a master head and a slave head,

A first step of moving a calibration plate below the master head and the slave head;

A second step of laser machining the array points to the master head with the plate;

When the first interval of the slave head from the master head is different from the second interval of the slave head from the master head at the time of processing the substrate to be processed, the slave head is linearly moved so that the Maintaining a spacing of a slave head at the second interval;

A fourth step of moving the plate by a distance obtained by subtracting the first interval from the second interval;

A fifth step of laser processing the array points with the slave head on the plate; And

And observing the processed array points sequentially to calculate an offset at each array point.

The calibration plate is divided into the master head processing area and the slave head processing area,

Each machining area is divided into a plurality of separate areas where the array points are processed.

In addition, the second step and the fifth step,

Dividing one rectangular area of the array points into a plurality of grids in the separated area; And

And shifting the array points in a predetermined direction so as to pass through the intersection points of the grid.

Also,

The fourth step,

Moving the plate in a direction of movement of the slave head.

Hereinafter, a method of calibrating a laser drilling system in a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

4 is a flowchart of a method of calibrating a laser drilling system according to a first embodiment of the present invention, in which the same reference numerals are used for members substantially the same as the components of the conventional embodiment, and detailed description thereof will be omitted.

Referring to FIG. 4, when the laser machining position of the dual head laser drilling system is to be corrected, the acrylic plate 80 is disposed below the dual head using the X-Y stage 60 (step 201). The acrylic plate 80 and the PCB substrate 50 may be disposed on the same X-Y stage 60.

Subsequently, the longitudinal length of the substrate 50 to be processed is bisected, and it is determined whether the master head 30 and the slave head 40 are disposed in predetermined regions, respectively (step 202). In Fig. 5, an acrylic plate 80 having a size of approximately 500 mm x 80 mm is bisected into a master head machining zone 81 and a slave head machining zone 82, and the first to fourth master machining zones are respectively divided into respective zones. (A1 to A4) and the first to fourth slave processing areas A5 to A8 are defined to be spaced apart from each other. Subsequently, in a state where the master head 30 is fixedly arranged in any one of the first to fourth master areas A1 to A4, the slave head 40 is any one of the first to fourth slave areas A1 to A4. Determine if it is placed in. When the new acrylic plate 80 is used for laser correction, the heads 30 and 40 are disposed in the first master area A1 and the first slave area A5, respectively.

In operation 202, when the slave head 40 is disposed out of the first slave area, the slave head 40 is moved to the first slave area by using the linear movement device 70 (operation 203). This is a process in which the first spacing between the master head 30 and the slave head matches the second spacing of the slave head 40 from the master head 30 during processing.

Subsequently, 9 × 9 array points are processed on the acrylic plate 80 with the master head 30 to form a 9 × 9 array groove (step 204). At this time, the diameter of the grooves may be approximately 100 ㎛ size, the interval of each groove may be 6 mm.

Subsequently, in the step 203, when the slave head 40 is linearly moved, the first slave area of the acrylic plate 80 is disposed below the slave head 40 by using the XY stage 60. Step 205). That is, the same distance is moved in the movement direction of the slave head 40.

Subsequently, 9 x 9 array points are processed on the acrylic plate 80 with the slave head 40 to form a 9 x 9 array groove (step 206). At this time, the diameter of the grooves may be approximately 100 ㎛ size, the interval of each groove may be 6 mm.

When the process of processing the array array grooves on the acrylic plate 80 is completed, the offset is calculated by observing each processed point with a vision camera, and the offset data is transmitted to the control unit (step 207). The controller corrects the error based on the transmitted data and subsequently performs laser drilling in consideration of the offset data during laser drilling in the region where the offset is calculated.

In the first embodiment, a method of fixing the slave area processed by the slave head 40 to a predetermined position by moving the acrylic plate 80 is proposed.

6 is a flowchart of a method of calibrating a laser drilling system according to a second embodiment of the present invention, in which the same reference numerals are used for members substantially the same as the components of the conventional embodiment, and detailed description thereof will be omitted.

First, the master head 30 is moved to the first master region (steps 301 and 302).

Next, Nj = 1 is defined (step 303), and the groove at the Nj position is machined (step 304).

Subsequently, Nj = Nj + 1 is increased (step 305), and it is determined whether Nj = 145 (step 306). In step 306, if Nj is less than 145, step 304 is performed.

FIG. 7 is a diagram for describing machining of 144 array points into one machining area A1. Referring to FIG. 7, one machining area A1 includes an array A1 'consisting of 9 x 9 machining array points, a 9 x 9 array point array A1 "shifted 500 m to the right from these A1', and an array A1. An array of A1 '' 'spaced apart from the maximum is shown.In one machining of 9 x 9 array points, the distance between the grooves is 6 mm and one array point is provided with a groove size of 100 μm. The pure areas A1 ', A1 ", A1"' occupy 6 mm x 8 + 100 µm, which is exactly 48.1 mm x 48.1 mm. In the array B, the reference point S The possible point is a position corresponding to the intersection point of the grid when the grid is formed at intervals of 500 μm of the quadrilateral area B composed of four array points including the reference point S. There are 144 reference points (S), and the 9 x 9 array points relative to each reference point (S) are distinguished from each other. It consists of points that are processed.

If it is determined in step 306 that Nj = 144, it means that laser processing correction is finished using one master area, and therefore, increases to Ni = Ni + 1 (step 307).

Next, it is determined whether Ni = 5 (step 308). In step 308, if Ni is determined to be less than 5, step 302 is repeated. In other words, the laser processing correction is continuously repeated in the new master area.

On the other hand, if it is determined in step 308 that Ni = 5, the correction operation in the acrylic plate 80 in use is terminated and a new acrylic plate 80 is prepared to perform the correction process of the above process.

Although the above-described process has described the correction step in the master area with the master head 30, this is for explanation, and in fact, the correction in the slave head areas A5 to A8 with the slave head 40 is also different from the second embodiment. The same is done.

According to the first and second embodiments, it is possible to perform machining correction of 576 master heads 30 and slave heads 40 using one acrylic plate 80.

As described above, according to the calibration method of the laser drilling system according to the present invention, the number of corrections can be increased by using an acrylic plate, thus reducing the material cost of the acrylic plate and reducing the time required for the acrylic plate replacement. It can contribute to the productivity improvement of the laser drilling system with the dual head.

Although the present invention has been described with reference to the embodiments with reference to the drawings, this is merely exemplary, it will be understood by those skilled in the art that various modifications and equivalent embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined only by the appended claims.

Claims (5)

In the calibration method of a laser drilling system having a master head and a slave head, A first step of moving a calibration plate below the master head and the slave head; A second step of laser machining the array points to the master head with the plate; When the first interval of the slave head from the master head is different from the second interval of the slave head from the master head at the time of processing the substrate to be processed, the slave head is linearly moved so that the Maintaining a spacing of a slave head at the second interval; A fourth step of moving the plate by a distance obtained by subtracting the first interval from the second interval; And a fifth step of laser processing the array points with the slave head on the plate. The method of claim 1, The calibration plate is divided into the master head processing area and the slave head processing area, Wherein each machining zone is divided into a plurality of separate zones in which the array points are machined. The method of claim 2, The second step and the fifth step, Dividing one rectangular area of the array points into a plurality of grids in the separated area; And Shifting the array points in a predetermined direction so as to pass through the intersection points of the grid; and processing the laser drilling system. The method of claim 1, The fourth step, And the plate is moved in a movement direction of the slave head. The method of claim 1, And the fifth step includes sequentially observing the machined array points and calculating an offset at each array point.

Images