JPH106067A - Laser beam machining equipment and its loading table - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce damages of a green sheet and a loading table, and to prevent the machining dust from being left in a through hole. SOLUTION: A loading table 12 is provided with a recessed part 2, and a plurality of cylindrical hollow rods 1 are arranged in parallel to each other with the prescribed intervals in an opening part of the recessed part 2, and a green sheet 5 is loaded on the hollow rods 1. The hollow rods 1 are formed of quartz with excellent transmissivity to the laser beam 3, and its surface is formed a ground glass so as to scatter the laser beam 3. The green sheet loaded on the loading table 12 is irradiated with the laser beam 3 to form a through hole 4. During the machining, the pressurized gas 8 is fed in the recessed part 2, and the cooling medium is circulated in the hollow rods 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus and a mounting table thereof, and more particularly to a laser processing apparatus and a mounting table for forming through holes in a sheet-shaped workpiece.

[0001]

2. Description of the Related Art In recent years, there has been an increasing need for through-hole processing in a green sheet formed by applying a material of a laminated electronic component to a sheet-shaped workpiece, particularly a substrate, in a thickness of about 10 μm to 500 μm. Have been doing. As a method for processing through holes in such a green sheet, 199
"Report of the Society of Laser Engineers of Japan" published on December 15, 1992
As disclosed in (Green Sheet Processing by YAG Laser), a processing method using a YAG laser has been put to practical use.

In this conventional laser processing apparatus, a mounting table for mounting a green sheet having a protective film crimped on the back surface is applied. This stage is made of a porous material, and the surface on which the back surface of the green sheet is adsorbed is roughened. The feature of this stage is that the green sheet can be flattened because the back surface of the green sheet is adsorbed by the porous material. Also, because the surface is roughened,
The laser light penetrating the green sheet can be scattered, and as a result, the back surface of the green sheet can be prevented from being damaged by the laser light reflected on the stage.

[0003]

However, in the conventional laser processing apparatus, since the stage is pressed over almost the entire surface of the green sheet, the stage itself is processed by the laser beam. There is. In particular, when processing a green sheet by condensing a laser beam on a small spot, the depth of focus is long and an energy density sufficient to process the surface of the stage is obtained. May be damaged.

Further, since the mounting table is in contact with almost the entire surface of the green sheet, the processing dust of the through hole processed by the laser beam is difficult to remove from the inside of the through hole and remains inside the through hole. There are also problems.

[0005]

In order to solve the above-mentioned problems, a mounting table of the present invention has a concave portion, and a plurality of rod-shaped members are arranged at predetermined openings in an opening of the concave portion. A sheet-like workpiece is placed on a rod-shaped member by line contact, wherein the rod-shaped member is formed of a material having high transmittance to laser light, and the surface scatters the laser light. It is processed as follows.

Further, the laser processing apparatus of the present invention has a concave portion, a plurality of rod-shaped members are arranged with a predetermined gap in an opening of the concave portion, and a sheet-shaped workpiece is line-contacted on the rod-shaped member. A laser processing apparatus comprising: a mounting table on which a workpiece is mounted; and a unit configured to irradiate a laser beam onto the workpiece mounted on the mounting table to form a through hole in the workpiece. The member is formed of a substance having high transmittance to laser light, and its surface is processed so as to scatter the laser light.

[0007]

Next, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a flowchart showing the operation thereof.

Referring to FIG. 1, a mounting table 12 has a recess 2 formed therein. A plurality of cylindrical hollow rods 1 are fixedly arranged in parallel with an opening of about 1 mm in the opening of the recess 2. The hollow rod 1 is formed of a material having a high transmittance to the laser light 3, for example, quartz, and its surface is processed into a ground glass shape to scatter the laser light 3.

The alumina-based ceramic green sheet 5 to be processed is arranged in line contact on a plurality of hollow bars 1 densely arranged with a predetermined gap. The peripheral portion of the green sheet 5 is pressure-bonded to the upper surface of a sheet holding frame 16 made of stainless steel. Further, the pressing roller 6 driven by a roller driving source 7 such as a cylinder presses one end of the sheet holding frame 16 and presses the other end of the sheet holding frame 16 against the positioning pin 10 so that the green sheet 5 is placed on the hollow rod 1. Is fixed at a predetermined position.

The pressurized gas 8 generated from the gas supply unit 13
Is supplied into the recess 2 through the flow path 11. The supplied pressurized gas 8 applies a pressure to the green sheet 5 on the hollow bar 1 such that the contact between the hollow bar 1 and the green sheet 5 is maintained, thereby preventing the green sheet 5 from bending. On the other hand, processing dust falling from the through hole 4 opened in the green sheet 5 by the laser light 3 is sucked by the dust collector 9, passes through the flow path 11, and is discarded outside.

Next, the operation of this embodiment will be described with reference to FIG.

First, in order to supply the green sheet 5 onto the stage 12, the roller drive source 7 is turned off (S10).
1) The holding roller 6 is opened from the position where the sheet holding frame 16 is fixed (S102). In this state, the green sheet 5 pressed on the sheet holding frame 16 is placed on the stage 1.
2 (S103), the roller drive source is turned on (S104), and the pressing roller 6 is driven to press the sheet holding frame 16 against the positioning pin 10 to fix it (S10).
5). The back surface of the green sheet 5 is supported in line contact on a plurality of hollow rods 1 arranged densely. Further, the pressurized gas 8 generated from the gas supply unit 13 is supplied into the recess 2 so that a certain pressure is applied to the back surface of the green sheet 5 (S106). As a result, the portion of the green sheet 5 that is not supported by the hollow bar 1 is also compressed with the pressurized gas 8.
The surface accuracy of the green sheet 5 is
Maintained with high accuracy. In this state, the green sheet 5 is irradiated with the laser beam 3 from above to process the through hole 4 (S107). At this time, since the laser light 3 that has passed through the green sheet 5 is transmitted and scattered through the hollow bar 1, it is possible to prevent the green sheet 5 and the stage 12 from being damaged by the laser light 3. . In addition, since the surface accuracy of the green sheet 5 is high, the laser beam 3 is applied to the green sheet 5 at a fixed angle, and as a result, uniform processing can be performed. The processing dust generated by the through-hole processing is formed in the recess 2.
Due to the air pressure caused by the pressurized gas 8 supplied to the inside, the inside of the through hole 4 is prevented from being retained. After the through-hole processing by the laser beam 3 is completed, the irradiation of the laser beam is stopped and the supply of the pressurized gas 8 is stopped (S1).
08). Here, processing dust generated at the time of through-hole processing accumulates at the bottom of the recess 2. Therefore, the dust collector 9
By operating, the processing dust accumulated at the bottom of the concave portion 2 is sucked and discarded outside through the flow path 11 (S109).

Further, in the present embodiment, by circulating a cooling medium inside the hollow rod, it is possible to reduce heating of the green sheet by laser processing and suppress thermal deterioration of the green sheet.

Referring to FIG. 3, a plurality of hollow rods 1 arranged in parallel with a predetermined gap are provided in a cooling medium circulation path 31.
To form a loop. Then, a cooling medium 33 such as pure cooling water generated from a cooling medium generating source 32 disposed on the loop is supplied to the circulation path 31, the hollow rod 1, and the circulation path 3.
It is circulated in a flow such as 1. Therefore, the cooling medium 33 is always circulating in the hollow rod 1, and the heating of the green sheet 5 during processing can be reduced.
Thus, the green sheet 5 is prevented from being heated by the irradiation of the laser beam 3, so that the green sheet 5 is prevented from being damaged and uniform laser processing is performed.

In this embodiment, a cylindrical rod-shaped member is used as the hollow rod. However, the present invention is not necessarily limited to this shape. As the hollow rod, for example, even when a cylindrical rod-shaped member having a triangular cross-section is applied, the green sheet and the rod-shaped support member come into contact with each other with a line, so that the effects of the present invention can be sufficiently achieved. Can be demonstrated.

Further, when processing is performed with a laser beam having a low output such that there is no need to cool the green sheet, it is not necessary to circulate a cooling medium in the hollow rod, so that it is necessary to form the hollow rod into a cylindrical shape. There is no. Therefore, in such a case, a rod-shaped member such as a simple glass rod may be used as the hollow rod.

Further, if an assist gas such as helium is used as a pressurized gas for pressurizing the back surface of the green sheet, processing characteristics can be improved.

[0019]

As described above, according to the present invention, the green sheet is set by a line contact on a plurality of rod-like members fixedly arranged in parallel with a predetermined gap. Can be maintained with high accuracy. Therefore, the laser beam for processing is always applied to the green sheet at the same angle, so that uniform processing can be performed.

Further, a plurality of rod-shaped members supporting the green sheet are formed of a material having a high transmittance to laser light, and the surface thereof is processed so that the laser light is scattered, so that the rod-like member passes through the green sheet. It is possible to reduce damage to the back surface of the green sheet and the stage by the laser light.

Further, with respect to the back surface of the green sheet,
By applying a predetermined pressure with the pressurized gas, it is possible to prevent processing dust from remaining inside the through holes formed in the green sheet. Furthermore, since the portion of the green sheet that is not supported by the rod-shaped member is also supported by the pressurized gas, the surface accuracy of the green sheet can be further improved.

Further, by forming the rod-shaped member for supporting the green sheet into a cylindrical shape and circulating a cooling medium therein, it is possible to prevent the green sheet from being heated and deteriorated by laser processing.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of one embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of another embodiment of the present invention, particularly a configuration for circulating a cooling medium in a hollow rod.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 hollow rod 2 concave portion 3 laser beam 4 through hole 5 green sheet 6 press roller 7 roller drive source 8 pressurized gas 9 dust collector 10 positioning pin 11 channel 12 mounting table body 13 gas supply device 16 sheet holding frame 31 cooling Medium circulation path 32 Cooling medium generation source 33 Cooling medium

Claims (7)

[Claims] 1. A plurality of rod-shaped members having a concave portion, on which a sheet-shaped workpiece is placed with a predetermined gap at an opening of the concave portion, wherein the rod-shaped member has a high transmittance to a laser beam. A stage which is formed of a material having the following, and whose surface is processed so as to scatter laser light. 2. The apparatus according to claim 1, further comprising means for supplying a gas into the recess and applying a pressure to the workpiece placed on the rod-shaped member by the gas. The stage described in. 3. The rod-shaped member is a cylindrical member, further comprising means for circulating a cooling medium for cooling the workpiece inside the cylindrical rod-shaped member. The stage according to claim 1. 4. The stage according to claim 1, further comprising means for discarding processing dust generated when processing the workpiece accumulated on the bottom of the concave portion with laser light. 5. A mounting table having a concave portion, a plurality of bar-shaped members are arranged in parallel with a predetermined gap in an opening of the concave portion, and a sheet-shaped workpiece is mounted on the bar-shaped member by line contact. A laser processing apparatus comprising: means for irradiating a laser beam onto the workpiece placed on the mounting table to form a through hole in the workpiece, wherein the rod-shaped member is a laser. A laser processing apparatus formed of a substance having a high transmittance to light and having a surface processed to scatter laser light. 6. A means for supplying helium for improving the processing characteristics by the laser beam into the recess, the helium being used to move the rod-shaped member with respect to the workpiece mounted on the rod-shaped member. 6. The laser processing apparatus according to claim 5, wherein a pressure is applied to maintain the contact between the laser beam and the workpiece. 7. The rod-shaped member is a cylindrical member, further comprising means for circulating a cooling medium for cooling the workpiece inside the cylindrical rod-shaped member. The laser processing device according to claim 5.