JP2006007286A - Laser beam machining apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser beam machining apparatus that can perform stable operation by improving deterioration of workability caused by silica produced in laser machining and preventing damage to protective glass or the like. <P>SOLUTION: The laser beam machining apparatus 1 is provided with a laser section 2, a laser machining section 3, and a dust collecting section 4. The laser machining section 3 is composed of an upper cover 21, a lower cover 22, a cover door 23, replacement glass 24, an replacement glass guide 25, a scattering silica receiving part 26, an upper scattering protective plate 27, and a lower scattering protective plate 28. The replaceable replacement glass 24 is installed in the upper rear center of the lower cover 22 and fixed to the upper rear face of the lower cover 22 by means of the replacement glass guide 25, transmitting a laser beam. The scattering silica receiving part 26 is fixed to the side face of the lower cover 22, with the upper and the lower scattering protective plate 27, 28 vertically installed around the four directions of the part transmitting the laser beam. Scattered silica is deposited on the upper face of the scattering silica receiving part 26. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a laser processing apparatus for processing a workpiece by irradiating a laser beam, and in particular, a laser processing apparatus used for deburring a resin-sealed semiconductor device sealed with a mold resin or the like, a laser mark, or the like. It is about.

  In recent years, resin-encapsulated semiconductor devices in which a semiconductor chip is mounted on a lead frame, the inner lead of the lead frame and each terminal of the semiconductor chip are connected, and resin-encapsulated with a resin mold have been required to be smaller and have higher performance. Yes. For this reason, it has become necessary to finely process the shape of the lead frame, the shape of the lead terminal, the shape of the resin-encapsulated semiconductor device, and the like with high precision. A laser processing apparatus is used as an effective means for processing a resin-encapsulated semiconductor device with high precision and fineness (see, for example, Patent Document 1).

  When this laser processing device is used for deburring a resin-encapsulated semiconductor device, cutting unnecessary leads, laser marks, etc., unnecessary resin components are burned and disappeared by laser irradiation, but from the surface of the resin-encapsulated semiconductor device Silica (SiO 2) as a filler that occupies 70% or more of the resin is scattered around. The scattered silica adheres to a drive unit that carries and positions the resin-encapsulated semiconductor device, and causes a malfunction.

  In addition, when the scattered silica collides with the protective glass made of borosilicate glass or the like provided at the front of the laser condenser lens, the silica has a higher hardness than the protective glass, so fine scratches on the surface of the protective glass. Occurs and the protective glass becomes ground glass. For this reason, there is a problem that the transmittance of the laser is lowered and the laser processing output is insufficient.

Furthermore, gas and water vapor generated during laser processing can be sucked, but the scattered silica is scattered on all sides of the laser processing device, or dropped and deposited around the resin-encapsulated semiconductor device irradiated with the laser. There is a problem that causes failure.
Japanese Patent Laid-Open No. 10-52781 (page 7, FIG. 1)

  An object of the present invention is to provide a laser processing apparatus that can improve workability deterioration due to silica generated during laser processing and that can perform stable operations while preventing damage to a protective glass or the like.

  In order to achieve the above object, a semiconductor device according to one embodiment of the present invention includes a laser unit that generates laser light and outputs the laser light from a processing head, and is fixed to the lower surface of the processing head to protect the processing head. An upper cover, a lower cover fixed to the lower surface of the upper cover and shielded from the outside, a replacement glass provided on the upper back surface of the lower cover and fixed to the upper back surface of the lower cover with a replacement glass guide; And a workpiece whose upper surface is covered with the lower cover includes a laser processing portion that is laser processed by the irradiated laser light through the replacement glass. And

  Furthermore, in order to achieve the above object, a semiconductor device according to another aspect of the present invention includes a laser unit that generates a laser beam and outputs the laser beam from a machining head, and is fixed to the lower surface of the machining head. An upper cover that is fixed to the lower surface of the upper cover and is shielded from the outside, and an upper scattering prevention plate that is fixed to the side surface of the lower cover and that passes through the four directions around the portion through which the laser beam is transmitted. A scattering silica receiving portion provided, and a lower scattering prevention plate fixed to the side surface of the lower cover below the scattering silica receiving portion and provided in four directions around the portion through which the laser beam is transmitted, A workpiece whose upper surface side is covered with the lower cover includes a laser processing unit that performs laser processing with the irradiated laser light.

  ADVANTAGE OF THE INVENTION According to this invention, the laser processing apparatus which can perform the stable operation | work which can improve the fall of workability | operativity by the silica which generate | occur | produces at the time of laser processing, and prevent damage to protective glass etc. can be provided.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, a laser processing apparatus according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a configuration of a laser processing apparatus, and FIG. 2 is a diagram illustrating an inside of a laser unit of the laser processing apparatus.

  As shown in FIG. 1, the laser processing apparatus 1 includes a laser unit 2, a laser processing unit 3, and a dust collection unit 4, and a plurality of resin-encapsulated semiconductor devices 41 provided on a conveyed lead frame 42. Deburring and sub-runner removal.

  The laser unit 2 includes a laser head 11 that outputs laser light, a processing head 12 that guides the laser light in a direction in which the resin-encapsulated semiconductor device 41 is mounted, and a position where the resin-encapsulated semiconductor device 41 performs laser processing. The resin-encapsulated semiconductor device 41 can be processed by scanning a laser beam with a galvanometer type optical scan method.

  The laser processing unit 3 includes an upper cover 21, a lower cover 22, a cover door 23, a replacement glass 24, a replacement glass guide 25, a scattering silica receiving portion 26, an upper scattering prevention plate 27, and a lower scattering prevention plate 28. ing. Here, the replacement glass 24 is made of borosilicate glass having a lower hardness than silica and excellent light transmittance.

  The upper cover 21 is fixed to the lower surface of the processing head 12 and protects the processing head 12 and the nozzle 14. The lower cover 22 is fixed to the lower surface of the upper cover. The cover door 23 is provided on the front surface of the lower cover 22 and can be opened and closed. The lower cover 22 and the cover door 23 that are in contact with the upper cover 21 at the center confine the gas, water vapor, and scattered silica generated from the resin-encapsulated semiconductor device 41 during laser irradiation.

  The replacement glass 24 is provided in the upper back center portion of the lower cover 22 and is fixed to the upper back surface of the lower cover 22 by the replacement glass guide 25 and transmits the laser light. In the replacement glass 24, when fine scratches are generated on the surface due to the scattered silica and become ground glass, the transmittance of the laser is lowered to cause insufficient laser processing output. For this reason, it is set as the structure which can replace | exchange for another glass immediately after removing the glass guide 25 for replacement | exchange.

  The scattering silica receiving part 26 is fixed to the side surface of the lower cover 22, and an upper scattering preventing plate 27 fixed to the scattering silica receiving part 26 is provided in the vertical direction in the four directions around the part through which the laser beam is transmitted. The scattered silica is deposited on the upper surface (first main surface) of the scattered silica receiving portion 26. The scattered silica receiving portion 26 has a structure in which when a predetermined amount of scattered silica is deposited on the upper surface, the cover door 23 is opened and closed, and the silica that has been detached from the lower cover 22 is discarded and fixed to the lower cover 22 again. . The lower scattering prevention plate 28 is fixed to the side surface of the lower cover 22 in the downward direction of the scattering silica receiving portion 26, is provided in the four directions around the portion through which the laser beam is transmitted, and is provided in the vertical direction. The upper scattering prevention plate 27 and the lower scattering prevention plate 28 prevent the silica generated during laser irradiation from scattering in the horizontal direction.

  The dust collecting portion 4 is fixed to the lower surface of the lower cover 22 and is a lower portion that guides gas generated from the resin-encapsulated semiconductor device 41 during laser irradiation, water vapor, and silica that could not be received by the scattered silica receiving portion 26 downward. It has a guide 31 and a suction port 32 for sucking them. Gas, water vapor, and silica that could not be received by the scattered silica receiving portion 26 are discharged to the outside through the suction port 32.

  A plurality of resin-encapsulated semiconductor devices 41 are provided on the lead frame 42, and the periphery of the upper surface side thereof is covered with the lower cover 22, and although not shown, the resin-encapsulated semiconductor device 41 is sequentially moved by a drive unit that carries and positions the resin-encapsulated semiconductor devices. Deburring and removal of the sub-runner are performed by the laser beam that is conveyed and generated from the laser unit 2.

  As shown in FIG. 2, a laser oscillator 51, a mask 53, a beam former 54, a cylindrical lens 55, a bending mirror 56, and a condenser lens 57 are provided inside the laser unit 2.

  The laser oscillator 51 generates, for example, YAG laser light 52 having a wavelength (λ) of 1064 nm and an output of 35 W by CW-Q switch oscillation. The width of the generated laser beam 52 is limited by the mask 53 before entering the beam former 54. The laser light 52 is beam-adjusted by a cylindrical lens 55 having a convex shape, for example, provided in a beam former 54. The laser light 52 is bent in the direction of the resin-encapsulated semiconductor device 41 by a bending mirror 56. When the laser beam 52 is scanned at an arbitrary position, the bending mirror 56 is replaced with an electronically controlled driving galvanometer mirror XY2. The bent laser beam 52 is collected by the condenser lens 57.

  Next, deburring and subrunner removal of the resin-encapsulated semiconductor device will be described with reference to FIGS. 3 is a plan view showing a resin-encapsulated semiconductor device before laser processing, FIG. 4 is a diagram showing a laser processing section immediately after laser irradiation, FIG. 5 is a diagram showing a laser processing section when silica is scattered, and FIG. It is a top view which shows the resin sealing semiconductor device after a process.

  As shown in FIG. 3, a plurality of resin-encapsulated semiconductor devices 41 in which a mold resin is injection-molded by a cavity are placed on the lead frame 42. The lead 45 is held by side frames 50 a and 50 b provided at both upper and lower ends along the longitudinal direction of the lead frame 42. The side frame 50 b is provided with a feed hole 44 for conveying the lead frame 42. The runner 46 is made of mold resin injected from the spray, is provided between the resin-encapsulated semiconductor devices 41, and is formed in a direction perpendicular to the side frames 50a and 50b. The sub runner 48 is made of a mold resin injected through a spray and a runner, and is formed between the runner 46 and the resin-encapsulated semiconductor device 41. The runner trace 47 is a mold resin trace injected from the spray.

  A position mark 43 having a concave shape for identifying the lead terminal number is provided at the lower right of the resin-encapsulated semiconductor device 41. In the portion of the lead 45 that contacts the resin-encapsulated semiconductor device 41, a lead-on burr 49 a made of mold resin and a lead-to-lead burr 49 b made of mold resin are left between the leads 45. A side burr 49 c made of mold resin is left in a portion of the sub runner 48 that contacts the resin-encapsulated semiconductor device 41.

  As shown in FIG. 4, in the laser processing unit 3 immediately after the laser irradiation, the laser light 52 condensed by the condenser lens 57 is irradiated to the resin-encapsulated semiconductor device 41 through the protective glass 15 and the replacement glass 24. Is done. Here, the replacement glass 24 is immediately after the replacement, and the laser transmittance does not decrease and the laser processing output is not insufficient. Further, immediately after the silica deposited on the upper surface of the scattered silica receiving portion 26 is discarded, the scattered silica is not deposited on the upper surface of the scattered silica receiving portion 26.

  As shown in FIG. 5, silica is generated from the resin-encapsulated semiconductor device 41 by laser irradiation in the laser processing portion when the silica is scattered. Most of the generated silica is squeezed, silica having a relatively small particle size and light weight is scattered upward, and silica 29 having a relatively large particle size and heavy weight falls downward, and gas, water vapor At the same time, it is discharged to the outside through the suction port 32.

  The scattered silica 29 is prevented from being scattered in the horizontal direction by the lower scattering prevention plate 28 and the upper scattering prevention plate 27, collides with the front surface of the replacement glass 24 and its periphery, loses its kinetic energy, and receives the scattered silica. Deposited on the upper surface of the portion 26. For this reason, it is possible to prevent the scattered silica and the silica falling downward from being scattered to the surrounding resin-encapsulated semiconductor device 41 and the drive unit that carries and positions the resin-encapsulated semiconductor device. The upper scattering prevention plate 27 and the lower scattering prevention plate 28 are preferably provided so as to overlap in the vertical direction in order to prevent the silica from scattering in the horizontal direction.

  As shown in FIG. 6, in the semiconductor device 41, by irradiating the laser beam 52, the lead top burr 49 a, the lead burr 49 b, and the sub runner 48 in contact with the resin-encapsulated semiconductor device 41 are removed. The sub-runner 48a after laser processing is separated from the resin-encapsulated semiconductor device 41.

  As described above, in the laser processing apparatus of the present embodiment, the replacement glass 24 fixed to the center of the upper surface of the lower cover 22 by the replacement glass guide 25 is provided in the laser processing unit 3. It can be replaced with another glass. For this reason, the exchange crow 24 becomes ground glass due to the scattered silica 29 generated at the time of laser irradiation, and even if the laser transmittance decreases and the laser processing output is insufficient, it can be immediately replaced with another glass. Will not be reduced. In addition, since the scattered silica does not collide with the protective glass 15 of the laser unit 2, the protective glass 15 can be prevented from being deteriorated.

  Further, an upper scattering prevention plate 27 and a lower scattering prevention plate 28 for preventing the silica scattered in the laser processing unit 3 from being scattered in the horizontal direction are provided, and a scattering silica receiving portion 26 for receiving the scattered silica is provided. ing. For this reason, it is possible to prevent the scattered silica from scattering to the surrounding resin-encapsulated semiconductor device 41 and the drive unit that carries and positions the resin-encapsulated semiconductor device. Does not cause an abnormality. In addition, the scattered silica receiving portion 26 on which the scattered silica is deposited on the upper surface can be easily removed from the lower cover 22 and can be fixed to the lower cover 22 again, so that it is not necessary to carry out the operation of removing the silica scattered around the work efficiency. Will not be reduced.

  Further, a lower guide 31 and a suction port 32 are provided immediately below the laser processing unit 3 for discharging gas, water vapor, and heavy silica generated during laser irradiation to the outside. For this reason, it is possible to prevent gas, water vapor, and heavy silica from being scattered to the surrounding resin-encapsulated semiconductor device 41 and the drive unit that carries and positions the resin-encapsulated semiconductor device. Does not cause abnormalities or abnormal operation of the drive unit. Moreover, it is not necessary to carry out the heavy silica removal operation, and the work efficiency is not reduced.

  In this embodiment, borosilicate glass is used as the replacement glass, but quartz glass may be used. In the case of using quartz glass, the replacement frequency of the replacement glass can be reduced because it is the same material as silica that is scattered during laser irradiation.

  Next, a laser processing apparatus according to Embodiment 2 of the present invention will be described with reference to the drawings. FIG. 7 is a plan view showing the resin-encapsulated semiconductor device before laser processing, and FIG. 8 is a plan view showing the resin-encapsulated semiconductor device after laser processing. In this embodiment, a laser mark is applied to the resin-encapsulated semiconductor device using the laser processing apparatus of the first embodiment.

  Hereinafter, in the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, the description thereof is omitted, and only different points will be described.

  As shown in FIG. 7, a plurality of resin-encapsulated semiconductor devices 41 from which runners are removed are mounted on the lead frame 42 by removing burrs, sub-runners, dampers, and the like with laser light or the like. Here, the laser mark portion 61 is laser-marked using, for example, YAG laser light having a wavelength (λ) of 1064 nm and an output of 15 W.

  As shown in FIG. 8, in the semiconductor device 41, a part of the upper surface of the semiconductor device 41 is removed by irradiating the laser beam, and a concave laser mark 62 is formed.

  As described above, in the laser processing apparatus of the present embodiment, the laser processing apparatus 1 of the first embodiment is used for the laser mark operation of the semiconductor device 41. For this reason, the stable operation | work can be performed efficiently like Example 1. FIG.

  The present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the invention.

For example, although a YAG laser is used in this embodiment, a YVO ₄ laser, a CO ₂ laser, or the like may be used. When a CO ₂ laser is used, it is preferably used for deburring a resin-encapsulated semiconductor device. Further, the present invention can be applied to cutting of leads of a resin-encapsulated semiconductor device and trimming of a semiconductor module. Furthermore, instead of the resin-encapsulated semiconductor device, the present invention may be applied to laser processing of a ceramic substrate containing silica (SiO 2).

The present invention can be configured as described in the following supplementary notes.
(Supplementary Note 1) A laser unit that generates laser light and outputs the laser light from a processing head, an upper cover fixed to the lower surface of the processing head and protecting the processing head, and fixed to the lower surface of the upper cover, A lower cover for shutting off, a replacement glass provided on the upper back surface of the lower cover, fixed to the upper back surface of the lower cover with a replacement glass guide, and easily removed and re-fixed on the side surface of the lower cover A scattering silica receiving portion that is fixed and has an upper scattering prevention plate in the four directions around the portion through which the laser beam is transmitted, and that is easy to remove and re-fix, and on the side of the upper cover that is lower than the scattering silica receiving portion A workpiece that is fixed and has a lower scattering prevention plate provided in the four directions around the portion through which the laser beam is transmitted, and whose workpiece is covered on the upper surface side with the lower cover. A laser processing portion that is laser processed by the irradiated laser light through the replacement glass and a lower surface of the lower cover are fixed, and the gas and silica generated from the workpiece are sucked and discharged to the outside. A laser processing apparatus comprising a dust collection unit.

(Supplementary note 2) The laser processing apparatus according to supplementary note 1, wherein the replacement glass is borosilicate glass.

(Additional remark 3) The said workpiece is a resin sealing semiconductor device, The laser processing apparatus of Additional remark 1 or 2 characterized by the above-mentioned.

The figure which shows the structure of the laser processing apparatus which concerns on Example 1 of this invention. The figure which shows the laser part of the laser processing apparatus which concerns on Example 1 of this invention. The figure which shows the resin-encapsulated semiconductor device before the laser processing which concerns on Example 1 of this invention. The figure which shows the inside of the laser processing part immediately after laser irradiation which concerns on Example 1 of this invention. The figure which shows the laser processing part at the time of the silica scattering which concerns on Example 1 of this invention. The figure which shows the resin sealing semiconductor device after the laser processing which concerns on Example 1 of this invention. The figure which shows the resin-encapsulated semiconductor device before the laser processing which concerns on Example 2 of this invention. The figure which shows the resin sealing semiconductor device after the laser processing which concerns on Example 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser processing apparatus 2 Laser part 3 Laser processing part 4 Dust collection part 11 Laser head 12 Processing head 13 Position detection camera 14 Nozzle 15 Protective glass 21 Upper cover 22 Lower cover 23 Cover door 24 Replacement glass 25 Replacement glass guide 26 Spattering silica receiving portion 27 Upper scattering prevention plate 28 Lower scattering prevention plate 29 Scattering silica 30 Deposited silica 31 Lower guide 32 Suction port 41 Resin sealing semiconductor device 42 Lead frame 43 Position mark 44 Feed hole 45 Lead 46 Runner 47 Runner trace 48 Sub Runner 48a Sub-runner 49a after laser processing Burr 49b on lead Burr 49c between leads Side burr 50a, 50b Side frame 51 Laser oscillator 52 Laser beam 53 Mask 54 Beam former 55 Cylindrical lens 56 Bending mirror 5 7 Condensing lens 61 Laser mark part 62 Laser mark

Claims (5)

A laser unit that generates laser light and outputs the laser light from a processing head;
An upper cover fixed to the lower surface of the processing head and protecting the processing head; a lower cover fixed to the lower surface of the upper cover and shielded from the outside; A workpiece having a replacement glass fixed to the upper back surface of the lower cover, and a workpiece whose upper side is covered with the lower cover is laser-induced by the laser light irradiated through the replacement glass. A laser machined part to be machined;
A laser processing apparatus comprising: A laser unit that generates laser light and outputs the laser light from a processing head;
An upper cover that is fixed to the lower surface of the processing head and protects the processing head, a lower cover that is fixed to the lower surface of the upper cover and is shielded from the outside, and is fixed to a side surface of the lower cover and transmits the laser light. A scattering silica receiving part provided with an upper scattering prevention plate in the four directions around the part, and fixed in the lower cover side face below the scattering silica receiving part, provided in the four directions around the part through which the laser beam is transmitted A laser processing unit having a lower scattering prevention plate formed, and a workpiece whose upper side is covered with the lower cover, which is laser processed by the irradiated laser beam;
A laser processing apparatus comprising: A laser unit that generates laser light and outputs the laser light from a processing head;
An upper cover fixed to the lower surface of the processing head and protecting the processing head; a lower cover fixed to the lower surface of the upper cover and shielded from the outside; Replacement glass fixed to the upper back surface of the lower cover, a scattering silica receiving portion fixed to the side surface of the lower cover and provided with an upper scattering prevention plate in the four directions around the portion through which the laser beam is transmitted, and the scattering silica A lower scattering prevention plate that is fixed to a side surface of the lower cover below the receiving portion and is provided in four directions around the portion through which the laser beam is transmitted, and the upper surface is covered with the lower cover. A laser processing section in which the workpiece is laser processed by the laser beam irradiated through the replacement glass;
A laser processing apparatus comprising:   The laser according to any one of claims 1 to 3, further comprising a dust collecting portion that is fixed to the lower surface of the lower cover and sucks gas generated from the workpiece and silica. Processing equipment.   The laser processing apparatus according to any one of claims 1 to 4, wherein the workpiece is a resin-encapsulated semiconductor device.

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