WO1999059761A1 - Laser machining method - Google Patents

Laser machining method Download PDF

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Publication number
WO1999059761A1
WO1999059761A1 PCT/JP1998/002239 JP9802239W WO9959761A1 WO 1999059761 A1 WO1999059761 A1 WO 1999059761A1 JP 9802239 W JP9802239 W JP 9802239W WO 9959761 A1 WO9959761 A1 WO 9959761A1
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WO
WIPO (PCT)
Prior art keywords
hole
workpiece
processing
substrate
laser beam
Prior art date
Application number
PCT/JP1998/002239
Other languages
French (fr)
Japanese (ja)
Inventor
Takayuki Yuyama
Masaru Kanaoka
Original Assignee
Mitsubishi Denki Kabushiki Kaisha
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Denki Kabushiki Kaisha filed Critical Mitsubishi Denki Kabushiki Kaisha
Priority to PCT/JP1998/002239 priority Critical patent/WO1999059761A1/en
Publication of WO1999059761A1 publication Critical patent/WO1999059761A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/16—Removal of by-products, e.g. particles or vapours produced during treatment of a workpiece
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/0011—Working of insulating substrates or insulating layers
    • H05K3/0017—Etching of the substrate by chemical or physical means
    • H05K3/0026—Etching of the substrate by chemical or physical means by laser ablation
    • H05K3/0032—Etching of the substrate by chemical or physical means by laser ablation of organic insulating material
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/11—Printed elements for providing electric connections to or between printed circuits
    • H05K1/115—Via connections; Lands around holes or via connections
    • H05K1/116—Lands, clearance holes or other lay-out details concerning the surrounding of a via
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/09—Shape and layout
    • H05K2201/09209—Shape and layout details of conductors
    • H05K2201/09654—Shape and layout details of conductors covering at least two types of conductors provided for in H05K2201/09218 - H05K2201/095
    • H05K2201/098—Special shape of the cross-section of conductors, e.g. very thick plated conductors
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/0011—Working of insulating substrates or insulating layers
    • H05K3/0017—Etching of the substrate by chemical or physical means
    • H05K3/0026—Etching of the substrate by chemical or physical means by laser ablation
    • H05K3/0032—Etching of the substrate by chemical or physical means by laser ablation of organic insulating material
    • H05K3/0035—Etching of the substrate by chemical or physical means by laser ablation of organic insulating material of blind holes, i.e. having a metal layer at the bottom
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/40—Forming printed elements for providing electric connections to or between printed circuits
    • H05K3/42—Plated through-holes or plated via connections
    • H05K3/425—Plated through-holes or plated via connections characterised by the sequence of steps for plating the through-holes or via connections in relation to the conductive pattern
    • H05K3/427—Plated through-holes or plated via connections characterised by the sequence of steps for plating the through-holes or via connections in relation to the conductive pattern initial plating of through-holes in metal-clad substrates

Definitions

  • the present invention relates to a laser processing method for processing a material such as a solid type print substrate, a flexible substrate, and a green sheet. And a laser processing method for forming through holes (hereinafter sometimes referred to as TH).
  • a laser processing method for processing a material such as a solid type print substrate, a flexible substrate, and a green sheet.
  • TH through holes
  • FIG. 1a is a diagram showing the conventional processing method for processing a via hole VH on a copper-clad substrate CS consisting of an insulating layer 3 with pot foils 2 formed on both sides, and Figure 1b shows a through-hole on a similar copper-clad substrate CS.
  • FIG. 4 is a view showing a conventional processing method for processing a hole TH.
  • These conventional laser processing methods are described in, for example, JP-A-4-136676, JP-A-5-184478 or JP-A-5-37756.
  • a hole 4 was formed by etching, and a laser beam 1 having a larger diameter than the hole 4 was irradiated. The feature of this method was that the etching was performed with a large beam diameter. According to this method, the diameter of the blind via hole or the through hole is determined by the etching hole 4.
  • FIG. 2a is a diagram showing a conventional processing method for processing a via hole VH on an insulating substrate IS consisting of an insulating layer 3 having a copper foil 2 only on the back surface
  • FIG. 6 is a diagram showing a conventional processing method for processing a through hole TH in such an insulating substrate IS.
  • These methods are performed due to the recent development of the build-up method of the substrate lamination by the build-up method.In this case, a blind via hole or a through-hole processing is performed on the insulating substrate IS, and thereafter, the entire surface is patterned. It is a method of forming. In this method, the hole diameter is determined by the diameter of the laser beam 1.
  • the laser processing method according to the present invention is a laser processing method for performing a drilling process using a laser beam on a substrate including an insulating layer and a copper layer provided on the insulating layer, wherein a hole is formed on the substrate.
  • the copper layer in the desired position is selectively removed by etching, and an etching hole having a diameter larger than the hole to be formed in the insulating layer is formed in the copper layer to expose the insulating layer.
  • This is a laser processing method that irradiates a laser beam with a diameter corresponding to the hole to be opened in the exposed insulating layer to make a hole in the insulating layer.
  • the present invention also provides a method for piercing a workpiece by irradiating the workpiece with a laser beam, wherein the laser beam is radiated from both sides of the workpiece to a boring position of the workpiece.
  • the laser processing method is also characterized by this.
  • the present invention also provides a processing method for irradiating a workpiece with a laser beam to remove a material of the workpiece, comprising irradiating the workpiece with a laser beam at a position corresponding to a removal processing position on both surfaces of the workpiece.
  • the laser processing method is characterized in that foreign matter generated by the removal processing is removed from the workpiece.
  • the laser beam may be simultaneously or at a time difference provided at positions corresponding to the removal processing positions on both surfaces of the workpiece. This is also a laser processing method characterized by irradiation.
  • the present invention provides a processing method for irradiating a workpiece with a laser beam to remove a material of the workpiece, wherein the workpiece can be peeled off in a post-process at a position corresponding to the removal processing position of the workpiece.
  • This laser processing method is characterized in that a thin film layer or a plate material is brought into close contact, a laser beam is applied to a position to be removed, and the thin film layer is removed.
  • FIG. 1a is a diagram showing a conventional processing method for processing a via hole in a copper-clad substrate.
  • FIG. 1b is a diagram showing a conventional processing method for processing through holes in a copper-clad substrate.
  • FIG. 2A is a diagram showing a conventional processing method for processing a via hole in an insulating substrate.
  • Figure 2b shows a conventional processing method for processing through holes in an insulating substrate. It is.
  • Fig. 3a is a schematic diagram of the shape of the processed wall surface when the beam position is shifted from the etched hole when forming a via hole in a copper-clad substrate using a conventional processing method.
  • Fig. 3b is a schematic diagram of the shape of the processed wall when the beam position is shifted from the etched hole when a through hole is formed in a copper-clad substrate using the conventional processing method.
  • FIG. 4 is a schematic diagram of a shape of a processing wall surface when a processing hole wall surface expands when a via hole is formed in a copper-clad substrate using a conventional processing method.
  • FIG. 5a is a schematic view showing a via hole formed by the processing method of the present invention.
  • FIG. 5b is a schematic view showing a through hole formed by the processing method of the present invention.
  • FIG. 6 is a diagram showing a method for evaluating the shape of the wall surface of a machined hole.
  • Figure a is a graph showing the measurement results of the hole shape processed by the conventional processing method.
  • Fig. B is a graph showing the measurement results of the hole shape processed by the processing method of the present invention.
  • Fig. 8 is a conceptual diagram showing a method of forming and processing a protective film on the back surface of a substrate
  • Fig. 9 is a conceptual diagram of a method of irradiating a laser on the front and back surfaces of a substrate to prevent the removal material from adhering to the back surface during surface processing
  • FIG. 10a is a graph showing a comparison of the difference in the amount of deposits on the back surface of the substrate by the processing method.
  • FIG. 10b is a plan view of the test material used in the comparative test of FIG. 10a.
  • Fig. 11 is a graph showing a comparison of the front and back hole diameters during through-hole processing for single-sided processing and double-sided processing.
  • Fig. 12 is a conceptual diagram of the process of changing the hole diameter on the substrate surface when multiple shots are input.
  • Fig. 13 is a conceptual diagram of the mechanism that affixes the film and suppresses the change of the hole diameter on the substrate surface when multiple shots are put in.
  • Figure 14 is a graph showing a comparison of the variation in the roundness of the surface hole with and without the film.
  • Fig. 15 is a graph showing the relationship between the film thickness and the hole diameter on the substrate surface during micro hole processing.
  • FIG. 5A is a schematic diagram showing a via hole VH formed by the processing method of the present invention
  • FIG. 5B is a schematic diagram showing a through hole TH formed by the processing method of the present invention.
  • the processing method of the present invention requires a somewhat smaller processing hole diameter for the copper-clad substrate CS, which is the insulating layer 3 having the foil 2 on both sides.
  • a large etching hole 4 is formed, and a hole is formed in the insulating layer 3 through the etching hole 4 with a laser beam 1 having a smaller diameter than the etching hole 4.
  • the hole 5 is machined. According to this method, it is possible to obtain the same peel strength of the pattern as that of the stretched substrate CS while maintaining the workability similar to that of the laser processing for the insulating substrate IS.
  • Fig. 6 shows the case where the insulating layer 3 was processed by irradiating a larger diameter beam to the etched hole 4 of the copper-clad substrate CS by the conventional method, and the case where the hole diameter was smaller than the etching hole 4.
  • An evaluation method for comparison with the case where the processing is performed on the insulating layer 3 is described.
  • the quality comparison of the hole wall shape was made by measuring the difference between the hole diameter at the surface and the hole diameter at the center of the machined hole in the depth direction. went.
  • Fig. 7a is a graph showing the results of measurement of the hole shape processed by the conventional processing method by the method shown in Fig. 6, and Fig. 7b is a graph of the hole shape processed by the processing method of the present invention.
  • 5 is a graph showing measurement results obtained by the method of FIG.
  • the vertical axis is the difference L (mm) between the hole diameter at the surface and the hole diameter at the center of the drilled hole, and the horizontal axis is the number of shots (times). Changes in energy density (m J Zmm 2 ) are shown.
  • the work material is copper-clad on the insulating layer t 0.1 mm of epoxy resin.
  • the irradiation beam diameter was 0.3 mm for the etching hole diameter of 0.1 mm
  • the etching hole diameter was 0.3 mm for the etching hole diameter of 0.3 mm. Processing is performed with an irradiation beam diameter of 0.1 mm.
  • the measured value L in the figure tends to increase.
  • the value of L may be a positive value (the wall surface is bulging outward).
  • the value of L is 0 at the maximum.
  • the wall surface does not bulge outward.
  • gaps may be created between the backside of the board and the processing tape in some cases.Because of such gaps and through holes, laser processing of the board surface, etc. In some cases, the removed substances such as carbides that have been generated may be transferred to the back surface of the substrate and adhere firmly, thereby hindering the plating. As shown in Fig.
  • step of taping 8 According to the method of this, it is necessary to peel off the tape 8 before performing the next step, according to c present invention the number of steps is more efficient had summer poor
  • First as shown in the left half of FIG. 9, first, the surface of the substrate IS is irradiated with the laser beam 1 for processing. At this time, as shown in the figure, the foreign matter 7 which is a removal substance goes around and adheres to the copper foil 2 on the back surface through the through hole TH.
  • the substrate IS on which the foreign matter 7 has adhered is turned upside down, and the laser beam 1 is again irradiated to remove the adhered matter.
  • a substrate processed by the double-sided irradiation method of the present invention shown in FIG. 9 and a substrate processed by the method using the protective film 8 shown in FIG. From the substrate that had been subjected to normal processing without the protective film 8, the amount of adhered foreign matter 7 after each processing was examined. The results are shown in Figure 1Oa, and the test materials used were shown in Figure 1Oa. Shown in b. As shown in Fig. 10b, 1 Ommxl 0 mm was applied to a substrate 3 (polyimide resin, thickness 50 jum) with 2 Omm x 5 mm copper foil 2 on one side, as shown in Fig. 10b. The processing was performed from the resin side to the area indicated by the square 9.
  • the substrate IS was fixed at a position of 1 Omm above the processing table without adhering to the processing table (not shown) in order to make it easier for the foreign material 7 of the resin material to wrap around.
  • the amount of the deposit 7 is defined as the area of the deposit 7 per unit area.
  • the surface hole diameter and the back surface hole diameter of the through hole can be made substantially equal.
  • Fig. 11 is a graph showing the results of comparison of the surface hole diameter and the back surface hole diameter of through-hole processing when processing is performed from only one side and when processing is performed from both sides by reversing the substrate after processing on one side.
  • Work material is FR-4 plate (thickness t 2
  • the processing conditions were 4 mJ per pulse and 40 Hz frequency in each case.
  • the number of shots is 10 shots from one side and 5 shots from each side from both sides.
  • the back hole diameter is about 60 m, and the back hole diameter is about 50% of the front hole diameter.
  • the surface hole diameter is about 100 jum and the backside hole diameter is also about 100 A ⁇ m, and the backside hole diameter is almost the same as the surface hole diameter (Approximately 100%).
  • the substrate IS is inverted in order to irradiate the laser beam 1 to both surfaces of the substrate IS.
  • the re-laser beam 1 can be illuminated simultaneously or with a time difference from the surface side. According to this method, the time can be significantly reduced as compared with the case where the substrate Is is inverted. For example, when processing 100,000 holes in the through hole TH processing described in the third embodiment, if a galvano scanner is used, the positioning of the holes can be performed in 2.O ms.
  • the hole shape on the surface may be distorted depending on the conditions.
  • a hole is drilled in a printed circuit board with a laser
  • a plurality of shots are usually taken.
  • a galvano scanner is often used to shorten the processing time.
  • Such an apparatus is susceptible to vibrations due to high-speed operation.
  • drilling holes in a substrate by laser beam irradiation as shown in FIG.
  • the first shot shown in the left half of the figure and the second shot shown in the right half caused beam misalignment, and the shape of the machined hole on the surface was distorted (distorted).
  • FIG. 13 shows the processing method of the present invention. That is, a resin film 12 such as a thin-film polyethylene or the like that can absorb laser energy is attached to the surface of the substrate 3 to be processed, and a hole is formed by irradiating a laser beam 1 thereon.
  • a resin film 12 such as a thin-film polyethylene or the like that can absorb laser energy is attached to the surface of the substrate 3 to be processed, and a hole is formed by irradiating a laser beam 1 thereon.
  • FIG. 14 is a graph showing the results of measuring the variation in the roundness of the surface hole diameter when holes were formed on the substrate on which the film 12 was not bonded and the substrate on which the film 12 was bonded.
  • the material to be processed is a hole with a diameter of ⁇ 100 ⁇ m made of epoxy (thickness t 50 m).
  • the processing conditions were 2 shots at 2 mJ of energy per pulse and 1 shot at a frequency of 1 Hz.
  • the roundness was (small diameter long diameter X 100), and the measurement was performed immediately after processing on the substrate without the film, and on the 25 holes each after peeling the film on the substrate with the film. As is clear from FIG. 14, the roundness of the hole of the substrate on which the film 12 is stuck is high and the variation is small.
  • the inner wall surface of the hole becomes a paper shape, and the hole diameter is formed at the tip of the paper. Becomes smaller. Therefore, by combining the reduction of the hole diameter due to this processing phenomenon with the high roundness of the hole of the substrate IS on which the film 12 is attached, it is possible to form a fine hole with high roundness. Become.
  • the graph of FIG. 15 shows the relationship between the thickness of the film 12 and the hole diameter on the surface of the substrate IS.
  • the workpiece is a substrate 12 having an epoxy resin thickness of 30 m.
  • the hole diameter at the surface of Fi Lum 1 2 was set to be ⁇ 8 0 A ⁇ m. Also, The number was changed according to the thickness of the film 12 so that the processing reached the inner layer copper foil. As is clear from this graph, when the film 12 becomes thicker, the hole diameter on the substrate surface tends to become smaller. Possibility of ffi
  • the laser processing method according to the present invention is directed to a laser processing method in which a substrate provided with an insulating layer and a copper layer provided on the insulating layer is drilled by a laser beam.
  • the copper layer is selectively removed by etching, and an etching hole having a diameter larger than the hole to be formed in the insulating layer is formed in the copper layer to expose the insulating layer, which is then exposed from the etching hole.
  • This is a laser processing method that irradiates a laser beam with a diameter corresponding to the hole to be formed in the insulating layer to make a hole in the insulating layer. With this method, it is possible to obtain a pattern peel strength equivalent to that of a copper-clad substrate, while maintaining the workability equivalent to that of laser processing of an insulating substrate.
  • the present invention also provides a method for piercing a workpiece by irradiating the workpiece with a laser beam, wherein the laser beam is radiated from both sides of the workpiece to a boring position of the workpiece.
  • This is also a laser processing method characterized by this. For this reason, the generation of paper at the time of through-hole processing is suppressed, and a hole processing close to a straight hole can be performed.
  • the present invention also provides a processing method for irradiating a workpiece with a laser beam to remove a material of the workpiece, comprising irradiating the workpiece with a laser beam at a position corresponding to a removal processing position on both surfaces of the workpiece.
  • the laser processing method is characterized in that foreign matter generated by the removal processing is removed from the workpiece. With this method, the rate of occurrence of defects in the subsequent steps can be suppressed.
  • a position corresponding to a removal processing position on both surfaces of the workpiece is also characterized in that the laser beams are irradiated simultaneously or with a time lag on the device. As described above, since the workpiece is machined simultaneously or slightly with a time lag from the front and back sides in two directions, high quality and short machining time can be achieved.
  • the present invention provides a processing method for irradiating a workpiece with a laser beam to remove a material of the workpiece, wherein the workpiece can be peeled off in a post-process at a position corresponding to the removal processing position of the workpiece.
  • This laser processing method is characterized in that a thin film layer or a plate material is brought into close contact, a laser beam is applied to a position to be removed, and the thin film layer is removed.
  • the thin film is adhered to the surface of the workpiece to be processed, the variation of the hole shape on the surface to be processed can be suppressed, and fine holes can be formed in the substrate. It is possible.

Abstract

A laser machining method capable of preventing bulging of the wall surfaces of the worked holes by applying a beam smaller in diameter than etched holes in a copper foil, providing a high peel strength by the use of a copper-clad substrate, preventing foreign substances from depositing by irradiating a laser beam from both sides of the substrate, enabling taper to be reduced substantially during the forming of through-holes, and limiting variations in the roundness of the worked holes by attaching a film or the like to the surfaces of the substrate during working.

Description

明 細 書 レーザ加工方法 腿分野  Description Laser processing method Thigh field
この発明は主にソリッ ド型のプリン卜基板ゃフレキシブル基板ゃグ リーンシート等の材料の加工を行うレーザ加工方法に関するもので、 高 品質なブラインドバイァホール （以下 B V Hと記載することもある） や スルーホール （以下 T Hと記載することもある） の形成加工を行うため のレーザ加工方法に関するものである。 背景技術  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing method for processing a material such as a solid type print substrate, a flexible substrate, and a green sheet. And a laser processing method for forming through holes (hereinafter sometimes referred to as TH). Background art
図 1 aは両面に鍋箔 2が形成された絶縁層 3からなる銅張り基板 C S にバイァホール V Hを加工する従来の加工方法を示す図であり、 図 1 b は同様の銅張り基板 C Sにスルーホール T Hを加工する従来の加工方法 を示す図である。 これらの従来のレーザ加工法は、 例えば、 特開平 4一 3 6 7 6、 特開平 5— 1 8 4 7 8あるいは特開平 5— 3 7 7 5 6に記載 されており、 銅張り基板 C Sにエッチングにて穴 4を形成した上で、 そ の穴 4よりも大径のレーザビーム 1 を照射するというものであった。 こ の方法の特徴はエッチング径ょリも大きいビーム径として加工を行うと いう点であった。 この方法によればブラインドバイァホールあるいはス ルーホールの穴径はエッチング穴 4によリ決定される。  Figure 1a is a diagram showing the conventional processing method for processing a via hole VH on a copper-clad substrate CS consisting of an insulating layer 3 with pot foils 2 formed on both sides, and Figure 1b shows a through-hole on a similar copper-clad substrate CS. FIG. 4 is a view showing a conventional processing method for processing a hole TH. These conventional laser processing methods are described in, for example, JP-A-4-136676, JP-A-5-184478 or JP-A-5-37756. A hole 4 was formed by etching, and a laser beam 1 having a larger diameter than the hole 4 was irradiated. The feature of this method was that the etching was performed with a large beam diameter. According to this method, the diameter of the blind via hole or the through hole is determined by the etching hole 4.
図 2 aは裏面にのみ銅箔 2を持つ絶縁層 3からなる絶縁基板 I Sにバ ィァホール V Hを加工する従来の加工方法を示す図であり、 図 2 bは同 様の絶縁基板 I Sにスルーホール T Hを加工する従来の加工方法を示す 図である。 これらの方法は、 近年ビルドアップ法による基板の積層技術 が発達してきたために行われる方法であって、 絶縁基板 I Sにブライン ドバイァホールあるいはスルーホール加工を行い、 その後に全面にめつ きしてパターンを形成する方法である。 この方法では穴径がレーザビー 厶 1 の径によって決定される。 Fig. 2a is a diagram showing a conventional processing method for processing a via hole VH on an insulating substrate IS consisting of an insulating layer 3 having a copper foil 2 only on the back surface, and Fig. 2b shows the same. FIG. 6 is a diagram showing a conventional processing method for processing a through hole TH in such an insulating substrate IS. These methods are performed due to the recent development of the build-up method of the substrate lamination by the build-up method.In this case, a blind via hole or a through-hole processing is performed on the insulating substrate IS, and thereafter, the entire surface is patterned. It is a method of forming. In this method, the hole diameter is determined by the diameter of the laser beam 1.
レーザを使用したプリン卜基板の加工用としては、 前述のブラインド バイァホールやスルーホールの他にブラインドバイァホールに類似した 形態であるがさらに大面積の除去加工等がある。 一般的にレーザでの加 ェは片面側からの加工が大半である。  For processing a printed substrate using a laser, in addition to the above-described blind via hole and through hole, there is a form similar to the blind via hole, but further processing for removing a larger area. Generally, laser processing is mostly done from one side.
また、 レーザによる加工の場合、 非接触加工であるため、 ドリルマシ ンの場合のようにあて板を用いる必要がなく、 通常被加工物の加工対象 面に直接レーザを照射していた。  In addition, in the case of processing by laser, since non-contact processing is performed, it is not necessary to use a contact plate as in the case of a drill machine, and the laser is usually directly irradiated onto the processing target surface of a workpiece.
図 1 aおよび図 1 bに示した方法にて加工を行う場合、 レーザビーム 1 が低次モードの場合、 ビーム 1 とエッチング穴 4の位置関係にずれが 生じた場合に加工穴のテーパに図 3 aおよび図 3 bに示すような偏リが 発生することがあるが、 このような偏リはめつき不良につながる可能性 があるため望ましくない。  When processing by the method shown in Fig.1a and Fig.1b, when laser beam 1 is in low-order mode, when the positional relationship between beam 1 and etching hole 4 is shifted, 3a and 3b may occur, but such unbalance is not desirable because it may lead to poor mounting.
また、 このような加工方法の場合、 開口径が銅箔により制限されるた め、 加工時に発生する樹脂の気化熱が抜けにく くなリ、 内層の銅箔 2に て反射したレーザビームがさらに表面の銅箔 2でも反射するため、 図 4 に示すように加工穴の壁面がエッチング穴径ょリも膨らむ傾向にある。 特に近年増えてきた薄い絶縁層の基板のブラインドバイァホール加工に 於いてこの傾向が顕著である。  In addition, in the case of such a processing method, since the opening diameter is limited by the copper foil, the heat of vaporization of the resin generated during the processing is hard to escape, and the laser beam reflected by the inner copper foil 2 is formed. Further, since the light is reflected by the copper foil 2 on the surface, as shown in FIG. 4, the wall surface of the processed hole tends to swell the etching hole diameter. This tendency is particularly remarkable in blind via hole processing of a substrate having a thin insulating layer, which has been increasing in recent years.
絶縁基板 I Sにレーザで直接ブラインドバイァホールあるいはスルー ホール加工を行う方法では加工後にめっきを施す。 そのため、 銅張り基 板 C Sに比べてピール強度が劣る。 これは銅張り基板 C Sでは、 銅箔 2 を張り合わせる工程にプレスを用いているため、 銅箔 2と絶縁層 3とが 密着するためである。 そのため、 加工後にエッチングしてパターンを形 成した場合に、 パターンと絶縁層 3の引っ張り強度が高い。 この点を克 服しなければ絶縁基板 I Sを用いることは難しい。 In the method of forming a blind via hole or a through hole directly on the insulating substrate IS using a laser, plating is performed after the processing. Therefore, copper-clad Peel strength is inferior to plate CS. This is because, in the copper-clad substrate CS, the copper foil 2 and the insulating layer 3 are in close contact with each other because a press is used in the step of bonding the copper foil 2. Therefore, when the pattern is formed by etching after processing, the tensile strength between the pattern and the insulating layer 3 is high. Unless this point is overcome, it is difficult to use the insulating substrate IS.
基板の構成は様々であるため、 場合によっては基板裏面と加工テープ ルの間に隙間が生じる。 このような隙間や基板自体のスルーホール丁 H の存在によリ基板裏面に強固に炭化物が付着しメツキの妨げになる場合 がある。  Since the configuration of the substrate is various, a gap is sometimes formed between the back surface of the substrate and the processing table. The presence of such gaps or through holes H in the substrate itself may cause carbides to adhere firmly to the rear surface of the substrate, which may hinder the plating.
また、 レーザの特性上片面よリスルーホール T H加工を行うと、 亍ー パが形成され、 ビーム入射側の径に比べて出射側の径が小さいため、 基 板を積層した時にスルーホールに段差が生じるといった問題があった。 更に被加工物の加工対象面にビームを直接照射した場合、 条件によつ ては表面の穴形状が歪になる。 表面の穴形状が歪であると、 めっき後に 特定の部分にのみ応力が集中し、 そこから破断する可能性がある。 発明の開示  Also, due to the characteristics of the laser, when the re-through hole TH processing is performed from one side, a paper is formed and the diameter on the output side is smaller than the diameter on the beam incident side. There was a problem that occurs. Furthermore, when the beam is directly irradiated on the surface to be processed of the workpiece, the hole shape on the surface is distorted depending on the conditions. If the surface has a distorted hole, stress concentrates only on a specific part after plating, and there is a possibility of fracture from there. Disclosure of the invention
本発明のレーザ加工方法は、 絶縁層と、 この絶縁層上に設けられた銅 層とを備えた基板にレーザビームによリ穴開け加工を行う レーザ加工方 法において、 基板上の穴を明けるべき位置にある銅層を選択的にエッチ ングによリ除去して、 絶縁層に開けるべき穴よリも大きな直径のエッチ ング穴を銅層に形成して絶縁層を露出させ、 エッチング穴から露出した 絶縁層に開けるべき穴に対応する直径のレーザビームを照射して、 絶縁 層に穴明けを行うレーザ加工法である。 この方法ならば、 加工性は絶縁 基板に対してレーザ加工する場合と同等でありながらパターンのピール 強度は鋇張リ基板と同等の値を得ることが可能である。 また、 本発明は、 被加工物にレーザビームを照射して被加工物に穴明 け加工を行う加工方法において、 被加工物の穴開け加工位置に被加工物 の両面からレーザビームを照射することを特徴とするレーザ加工法でも のる。 The laser processing method according to the present invention is a laser processing method for performing a drilling process using a laser beam on a substrate including an insulating layer and a copper layer provided on the insulating layer, wherein a hole is formed on the substrate. The copper layer in the desired position is selectively removed by etching, and an etching hole having a diameter larger than the hole to be formed in the insulating layer is formed in the copper layer to expose the insulating layer. This is a laser processing method that irradiates a laser beam with a diameter corresponding to the hole to be opened in the exposed insulating layer to make a hole in the insulating layer. According to this method, it is possible to obtain the same value of the pattern peel strength as that of the stretched substrate, while the processability is the same as that of the laser processing for the insulating substrate. The present invention also provides a method for piercing a workpiece by irradiating the workpiece with a laser beam, wherein the laser beam is radiated from both sides of the workpiece to a boring position of the workpiece. The laser processing method is also characterized by this.
また、 本発明は、 被加工物にレーザビームを照射して被加工物の材料 の除去加工を行う加工方法において、 被加工物の両面の除去加工位置に 対応する位置にレーザビームを照射して、 除去加工によリ発生した異物 を被加工物から取り除くことを特徴とするレーザ加工法でもある。 また、 被加工物にレーザビームを照射して被加工物の材料の除去加工 を行う加工方法において、 被加工物の両面の除去加工位置に対応する位 置にレーザビームを同時にあるいは時間差を設けて照射することを特徴 とするレーザ加工法でもある。  The present invention also provides a processing method for irradiating a workpiece with a laser beam to remove a material of the workpiece, comprising irradiating the workpiece with a laser beam at a position corresponding to a removal processing position on both surfaces of the workpiece. In addition, the laser processing method is characterized in that foreign matter generated by the removal processing is removed from the workpiece. Further, in a processing method for irradiating a workpiece with a laser beam to remove the material of the workpiece, the laser beam may be simultaneously or at a time difference provided at positions corresponding to the removal processing positions on both surfaces of the workpiece. This is also a laser processing method characterized by irradiation.
更に、 本発明は、 被加工物にレーザビームを照射して被加工物の材料 の除去加工を行う加工方法において、 被加工物の除去加工位置に対応す る位置に後工程にて剥離可能な薄膜層あるいは板材を密着させ、 除去加 ェ位置にレーザビームを照射して、 薄膜層を除去した後に被加工物の材 料の除去加工を行うことを特徴とするレーザ加工法である。 図面の簡単な説明  Further, the present invention provides a processing method for irradiating a workpiece with a laser beam to remove a material of the workpiece, wherein the workpiece can be peeled off in a post-process at a position corresponding to the removal processing position of the workpiece. This laser processing method is characterized in that a thin film layer or a plate material is brought into close contact, a laser beam is applied to a position to be removed, and the thin film layer is removed. BRIEF DESCRIPTION OF THE FIGURES
図 1 aは銅張り基板にバイァホールを加工する従来の加工方法を示す 図である。  FIG. 1a is a diagram showing a conventional processing method for processing a via hole in a copper-clad substrate.
図 1 bは銅張り基板にスルーホールを加工する従来の加工方法を示す 図である。  FIG. 1b is a diagram showing a conventional processing method for processing through holes in a copper-clad substrate.
図 2 aは絶縁基板にバイァホールを加工する従来の加工方法を示す図 である。  FIG. 2A is a diagram showing a conventional processing method for processing a via hole in an insulating substrate.
図 2 bは絶縁基板にスルーホールを加工する従来の加工方法を示す図 である。 Figure 2b shows a conventional processing method for processing through holes in an insulating substrate. It is.
図 3 aは従来の加工法を用いて銅張り基板にバイァホールを形成する 場合にエッチング穴とビーム位置がずれた場合の加工壁面の形状の模式 図である。  Fig. 3a is a schematic diagram of the shape of the processed wall surface when the beam position is shifted from the etched hole when forming a via hole in a copper-clad substrate using a conventional processing method.
図 3 bは従来の加工法を用いて銅張り基板にスルーホールを形成する 場合にエッチング穴とビーム位置がずれた場合の加工壁面の形状の模式 図である。  Fig. 3b is a schematic diagram of the shape of the processed wall when the beam position is shifted from the etched hole when a through hole is formed in a copper-clad substrate using the conventional processing method.
図 4従来の加工方法を用いて銅張り基板にバイァホールを形成する場 合に加工穴壁面が膨らんだ場合の加工壁面の形状の模式図である。  FIG. 4 is a schematic diagram of a shape of a processing wall surface when a processing hole wall surface expands when a via hole is formed in a copper-clad substrate using a conventional processing method.
図 5 aは本発明の加工方法によリ形成したバイァホールを示す模式図 である。  FIG. 5a is a schematic view showing a via hole formed by the processing method of the present invention.
図 5 bは本発明の加工方法によリ形成したスルーホールを示す模式図 である。  FIG. 5b is a schematic view showing a through hole formed by the processing method of the present invention.
図 6は加工穴壁面の形状の評価方法を示した図である。  FIG. 6 is a diagram showing a method for evaluating the shape of the wall surface of a machined hole.
図フ aは従来の加工方法により加工した穴形状の測定結果を示すグラ フである。  Figure a is a graph showing the measurement results of the hole shape processed by the conventional processing method.
図フ bは本発明の加工方法によリ加工した穴形状の測定結果を示すグ ラフである。  Fig. B is a graph showing the measurement results of the hole shape processed by the processing method of the present invention.
図 8は基板裏面に保護膜を形成して加工する方法を示す概念図である ( 図 9は基板表裏面にレーザを照射し表面加工時の除去物質の裏面への 付着を防ぐ方法の概念図である。 Fig. 8 is a conceptual diagram showing a method of forming and processing a protective film on the back surface of a substrate ( Fig. 9 is a conceptual diagram of a method of irradiating a laser on the front and back surfaces of a substrate to prevent the removal material from adhering to the back surface during surface processing) It is.
図 1 0 aは加工法による基板裏面への付着物の量の差の比較を示すグ ラフである。  FIG. 10a is a graph showing a comparison of the difference in the amount of deposits on the back surface of the substrate by the processing method.
図 1 0 bは図 1 0 aの比較試験に用いた試験材料の平面図である。 図 1 1 は片面加工と両面加工のスルーホール加工時の表裏の穴径の比 較を示すグラフである。 図 1 2は複数ショッ 卜投入時の基板表面の穴径が変化する過程の概念 図である。 FIG. 10b is a plan view of the test material used in the comparative test of FIG. 10a. Fig. 11 is a graph showing a comparison of the front and back hole diameters during through-hole processing for single-sided processing and double-sided processing. Fig. 12 is a conceptual diagram of the process of changing the hole diameter on the substrate surface when multiple shots are input.
図 1 3はフイルムを貼り、 複数ショッ 卜投入時の基板表面の穴径変化 を抑制する機構の概念図である。  Fig. 13 is a conceptual diagram of the mechanism that affixes the film and suppresses the change of the hole diameter on the substrate surface when multiple shots are put in.
図 1 4はフイルムの有無による表面穴の真円度のばらつきの比較を示 すグラフである。  Figure 14 is a graph showing a comparison of the variation in the roundness of the surface hole with and without the film.
図 1 5は微細穴加工時のフイルムの厚みと基板表面での穴径の関係を 示すグラフである。  Fig. 15 is a graph showing the relationship between the film thickness and the hole diameter on the substrate surface during micro hole processing.
%m^MM るための量良 Good quantity for% m ^ MM
実施の形態 1 . Embodiment 1
図 5 aは本発明の加工方法によリ形成したバイァホール V Hを示す模 式図であり、 図 5 bは本発明の加工方法によリ形成したスルーホール T Hを示す模式図である。 これらの図から理解されるように、 本発明の加 ェ方法は、 両面に鋇箔 2を有する絶縁層 3である銅張り基板 C Sに対し, 最終的に必要な加工穴径ょリも幾分大きいエッチング穴 4を作成し、 こ のエッチング穴 4を通して絶縁層 3に対してエッチング穴 4よリも小径 のレーザビーム 1 で穴加工をし、 絶縁層 3にエッチング穴 4よりも小さ ぃ径の加工穴 5を加工するものである。 この方法ならば、 加工性は絶縁 基板 I Sに対してレーザ加工する場合と同等でありながらパターンの ピール強度は鋇張リ基板 C Sと同等の値を得ることが可能である。  FIG. 5A is a schematic diagram showing a via hole VH formed by the processing method of the present invention, and FIG. 5B is a schematic diagram showing a through hole TH formed by the processing method of the present invention. As can be understood from these figures, the processing method of the present invention requires a somewhat smaller processing hole diameter for the copper-clad substrate CS, which is the insulating layer 3 having the foil 2 on both sides. A large etching hole 4 is formed, and a hole is formed in the insulating layer 3 through the etching hole 4 with a laser beam 1 having a smaller diameter than the etching hole 4. The hole 5 is machined. According to this method, it is possible to obtain the same peel strength of the pattern as that of the stretched substrate CS while maintaining the workability similar to that of the laser processing for the insulating substrate IS.
図 6には、 従来方法により銅張り基板 C Sのエッチング穴 4に対して， それよリも大径のビームを照射し絶縁層 3を加工した場合と、 エツチン グ穴 4よりも小さな穴径の加工を絶縁層 3に行った場合との比較を行う ための評価方法を示す。 穴壁面の形状の品質比較は、 図 6に示すように 表面部での穴径と加工穴の深さ方向中問部での穴径との差しを測定して 行った。 Fig. 6 shows the case where the insulating layer 3 was processed by irradiating a larger diameter beam to the etched hole 4 of the copper-clad substrate CS by the conventional method, and the case where the hole diameter was smaller than the etching hole 4. An evaluation method for comparison with the case where the processing is performed on the insulating layer 3 is described. As shown in Fig. 6, the quality comparison of the hole wall shape was made by measuring the difference between the hole diameter at the surface and the hole diameter at the center of the machined hole in the depth direction. went.
測定値の Lの値が負ならば穴壁面はすリ鉢状のテーパ形状を示してお リ、 メツキつき回り性も良い。 逆に正ならば穴の中間部で穴が膨らんで いて穴壁面は凹んでおリメツキつき回り性が劣る。 L = 0の時は穴がス トレートである。 これらの点から考慮すれば、 測定値 Lが負の時が良品, と判定され、 正の時が不良品と判定される。  If the measured value of L is negative, the hole wall surface has a tapered shape like a mortar, and the stickiness is good. Conversely, if it is positive, the hole swells in the middle of the hole, the wall surface of the hole is concave, and the roundness is poor and the roundness is poor. When L = 0, the hole is straight. Considering these points, when the measured value L is negative, it is determined to be good, and when positive, it is determined to be defective.
図 7 aは従来の加工方法により加工した穴形状を図 6に示す方法によ リ測定した結果を示すグラフであり、 図 7 bは本発明の加工方法によリ 加工した穴形状の図 6の方法による測定結果を示すグラフである。 これ らのグラフに於いて、 縦軸は表面部での穴径と、 加工穴中問部での穴径 との差 L (mm) 、 横軸はショッ ト数 （回） であり、 様々なエネルギ密 度 （m J Zmm 2 ) についての変化を示している。 また、 被加工材はェ ポキシ系樹脂の絶縁層 t 0. 1 mmに対して銅張りを行っている。 従来 例はエッチング穴径 Φ 0. 1 mmに対し、 φ 0. 3 mmの照射ビー厶径 で加工しているのに対し、 本発明によれば、 エッチング穴径 0. 3 mm に対し、 φ 0. 1 mmの照射ビーム径で加工するのである。 Fig. 7a is a graph showing the results of measurement of the hole shape processed by the conventional processing method by the method shown in Fig. 6, and Fig. 7b is a graph of the hole shape processed by the processing method of the present invention. 5 is a graph showing measurement results obtained by the method of FIG. In these graphs, the vertical axis is the difference L (mm) between the hole diameter at the surface and the hole diameter at the center of the drilled hole, and the horizontal axis is the number of shots (times). Changes in energy density (m J Zmm 2 ) are shown. The work material is copper-clad on the insulating layer t 0.1 mm of epoxy resin. In the conventional example, the irradiation beam diameter was 0.3 mm for the etching hole diameter of 0.1 mm, whereas according to the present invention, the etching hole diameter was 0.3 mm for the etching hole diameter of 0.3 mm. Processing is performed with an irradiation beam diameter of 0.1 mm.
エネルギ密度が高くショッ 卜数が多いほど図の測定値 Lは大きな値と なる傾向にある。 しかし、 従来加工方法に於いては、 Lの値が正の値を 示す場合がある （穴壁面が外側に膨らんでいる） 力 本発明の方法によ れば Lの値は最大でも 0であり、 穴壁面が外側に膨らむことはない。 実施の形態 2.  As the energy density increases and the number of shots increases, the measured value L in the figure tends to increase. However, in the conventional machining method, the value of L may be a positive value (the wall surface is bulging outward). According to the method of the present invention, the value of L is 0 at the maximum. However, the wall surface does not bulge outward. Embodiment 2.
基板の構成は様々であるため、 場合によっては基板裏面と加工テープ ルの間に隙間が生じることがあリ、 このような隙間やスルーホールの存 在のために、 基板表面のレーザ加工時等に発生した炭化物等の除去物質 が基板裏面に回リ込んで強固に付着しメツキの妨げになる場合がある。 図 8に示す如く、 スルーホール T Hが存在するかあるいは何らかの理 由で基板 I sの裏面と図示してない加工テーブルとの間に隙間 （図示し てない） が生じた基板 I sにおいて、 他の加工 （図の場合ではブライン ドバイァホール B V Hだがスルーホール T H加工でも同様） 時に発生す る除去物質等の異物 7力 スルーホール T Hあるいはその他の隙間を 通って基板 I Sの裏面に付着することがある。 これを防ぐために、 従来 は図 8に示すように予め基板 I Sの裏面の銅箔 2上にテープやフイルム 等の保護膜 8を形成して異物フの付着を防いでいた。 しかしながら、 こ の方法によればテープ 8を貼る工程が必要であるし、 次工程の実行前に テープ 8を剥がす必要があるため、 工程数が多く効率が悪くなつていた c 本発明によれば、 まず図 9の左半分に示すように、 まず第 1 に基板 I Sの表面にレーザビーム 1 を照射して加工を行う。 この時図に示すよう に除去物質である異物 7がスルーホール T Hを通って裏面の銅箔 2上に 回り込み付着してしまう。 次に図 9の右半分に示すように、 このように 異物 7が付着した基板 I Sを反転させて裏返し、 再びレーザビーム 1 を 照射して付着物フを除去する。 Due to the variety of board configurations, gaps may be created between the backside of the board and the processing tape in some cases.Because of such gaps and through holes, laser processing of the board surface, etc. In some cases, the removed substances such as carbides that have been generated may be transferred to the back surface of the substrate and adhere firmly, thereby hindering the plating. As shown in Fig. 8, there is a through hole TH In the case of a substrate I s where a gap (not shown) has occurred between the back surface of the substrate I s and the processing table (not shown) for this reason, other processing (in the case of the figure, a blind via hole BVH, but also a through hole TH processing) Foreign substances such as removed substances generated at the time 7) Through-holes TH or other gaps may adhere to the back surface of the substrate IS. In order to prevent this, conventionally, as shown in FIG. 8, a protective film 8 such as a tape or a film was previously formed on the copper foil 2 on the back surface of the substrate IS to prevent adhesion of foreign matter. However, It is necessary step of taping 8 According to the method of this, it is necessary to peel off the tape 8 before performing the next step, according to c present invention the number of steps is more efficient had summer poor First, as shown in the left half of FIG. 9, first, the surface of the substrate IS is irradiated with the laser beam 1 for processing. At this time, as shown in the figure, the foreign matter 7 which is a removal substance goes around and adheres to the copper foil 2 on the back surface through the through hole TH. Next, as shown in the right half of FIG. 9, the substrate IS on which the foreign matter 7 has adhered is turned upside down, and the laser beam 1 is again irradiated to remove the adhered matter.
本発明の効果を確認するために、 図 9に示す本発明の両面照射方法に よリ加工した基板と、 図 8に示す保護膜 8を用いた方法にて加工を行つ た基板と、 片面から保護膜 8無しで通常の加工を行った基板とを、 それ ぞれの加工後の付着異物 7の量について調べ、 その結果を図 1 O aに示 し、 使用した試験材料を図 1 O bに示す。 付着量を調べるため、 図 1 0 bに示す如く、 片面に 2 O m m X 5 m mの銅箔 2を張った基板 3 (樹脂 はポリイミ ド、 厚み 5 0 ju m ) に 1 O m m x l 0 m mの加工を正方形 9 で示す範囲に樹脂側から行った。 樹脂材料の異物 7の回り込みの効果が 現れやすくするため基板 I Sは加工テーブル （図示してない） に密着さ せず、 テーブル上 1 O m mの位置に固定した。 付着物 7の量は単位面積 当たりに占める付着物 7の面積としている。 図 1 0 aより表面加工後、 裏面にレーザを照射することで著しく付着量が低減していることがわか る、 なお、 付着量の測定は、 保護膜 8を貼ったものは保護膜 8を剥離し た後に測定した。 In order to confirm the effects of the present invention, a substrate processed by the double-sided irradiation method of the present invention shown in FIG. 9 and a substrate processed by the method using the protective film 8 shown in FIG. From the substrate that had been subjected to normal processing without the protective film 8, the amount of adhered foreign matter 7 after each processing was examined.The results are shown in Figure 1Oa, and the test materials used were shown in Figure 1Oa. Shown in b. As shown in Fig. 10b, 1 Ommxl 0 mm was applied to a substrate 3 (polyimide resin, thickness 50 jum) with 2 Omm x 5 mm copper foil 2 on one side, as shown in Fig. 10b. The processing was performed from the resin side to the area indicated by the square 9. The substrate IS was fixed at a position of 1 Omm above the processing table without adhering to the processing table (not shown) in order to make it easier for the foreign material 7 of the resin material to wrap around. The amount of the deposit 7 is defined as the area of the deposit 7 per unit area. After surface processing from Fig. 10a, It can be seen that the amount of adhesion was significantly reduced by irradiating the back surface with laser. The amount of adhesion was measured after the protective film 8 was peeled off when the protective film 8 was adhered.
実施の形態 3 . Embodiment 3.
また、 レーザの特性上基板の片面からスルーホール加工を行うと、 ス ルーホールの内壁面に亍ーパが形成され、 ビーム入射側の穴径に比べて 出射側の穴径が小さいため、 基板を積層した時にスルーホールの内壁面 に段差が生じてメツキの連続性や付着性に悪影響を与えてしまうという 問題があった。  Also, due to the characteristics of the laser, if through-hole processing is performed from one side of the substrate, paper is formed on the inner wall surface of the through-hole, and the hole diameter on the emission side is smaller than the hole diameter on the beam entrance side. There is a problem that a step is formed on the inner wall surface of the through hole when the layers are stacked, which adversely affects the continuity and adhesion of the plating.
本発明によれば、 基板両面からレーザ照射を行ってスルーホールを形 成することでスルーホールの表面穴径と裏面穴径とをほぼ等しくするこ とができる。  According to the present invention, by irradiating laser from both sides of the substrate to form a through hole, the surface hole diameter and the back surface hole diameter of the through hole can be made substantially equal.
図 1 1 には、 片面からのみ加工した場合と片面加工後基板を反転させ 両面から加工した場合のスルーホール加工の表面穴径と裏面穴径につい て比較した結果をグラフにして示す。 被加工材は F R— 4板 （厚み t 2 Fig. 11 is a graph showing the results of comparison of the surface hole diameter and the back surface hole diameter of through-hole processing when processing is performed from only one side and when processing is performed from both sides by reversing the substrate after processing on one side. Work material is FR-4 plate (thickness t 2
0 0 ju m ) である。 加工条件は、 どちらの場合も 1 パルス当たりのエネ ルギを 4 m J、 周波数 4 0 H zとしている。 ショッ ト数は片面からの場 合は 1 0ショッ 卜投入し、 両面からの場合はそれぞれの面から 5ショッ トづっ投入している。 図 1 1 のグラフから明らかなように片面のからの 照射加工では表面穴径が約 1 2 0 mのとき裏面穴径は約 6 0 mで、 裏面穴径は表面穴径の約 5 0 %であるのに対し、 両面からの照射加工の 場合には表面穴径が約 1 0 0 ju mで裏面穴径も約 1 0 0 A< mで、 裏面穴 径は表面穴径とほぼ同径 （約 1 0 0 % ) となった。 0 0 ju m). The processing conditions were 4 mJ per pulse and 40 Hz frequency in each case. The number of shots is 10 shots from one side and 5 shots from each side from both sides. As is evident from the graph in Fig. 11, in the irradiation processing from one side, when the front hole diameter is about 120 m, the back hole diameter is about 60 m, and the back hole diameter is about 50% of the front hole diameter. In contrast, in the case of irradiation processing from both sides, the surface hole diameter is about 100 jum and the backside hole diameter is also about 100 A <m, and the backside hole diameter is almost the same as the surface hole diameter (Approximately 100%).
実施の形態 4 . Embodiment 4.
実施の形態 2及び 3に於いては、 レーザビーム 1 を基板 I Sの両面に 照射するために基板 I Sを反転させるとして説明したが、 基板 I Sの両 面側から同時にあるいは時間差を付けることによリ レーザビーム 1 の照 射を行うことができる。 この方法によれば、 基板 I sを反転させる場合 に比べ大幅な時間短縮ができる。 例えば実施の形態 3で示したスルー ホール T H加工の場合で 1 0、 0 0 0個の穴を加工する場合、 ガルバノ スキャナを用いると穴の位置決めが 2. O m sで行えるため、 1 0、 0 0 0個の穴開けのための位置決め時間は、 （ 1 0、 0 0 0— 1 ) X 2. 0/ 1 0 0 0 = 1 9. 9 9 8秒となる。 片面から各穴に 4 0 H zで 1 0 ショッ ト投入すると、 （ 1 0— 1 ) Z 4 0 X 1 0、 0 0 0 + 1 9. 9 9 8 = 2 2 6 9. 9 9 8秒となる。 この値は基板 I Sを反転させる方法で の反転時間を除いた最低加工に要する時間となる。 そのため、 実際はさ らに長い時間必要となる。 一方、 両面同時に加工する場合、 反転する時 間が必要ない上、 片面それぞれに必要なショッ 卜が 5ショッ 卜でよいた め、 2 2 6 9. 9 9 8 / 2 = 1 1 3 4. 9 9 9秒となり、 加工に要する 時間は半分で済む。 In the second and third embodiments, the substrate IS is inverted in order to irradiate the laser beam 1 to both surfaces of the substrate IS. The re-laser beam 1 can be illuminated simultaneously or with a time difference from the surface side. According to this method, the time can be significantly reduced as compared with the case where the substrate Is is inverted. For example, when processing 100,000 holes in the through hole TH processing described in the third embodiment, if a galvano scanner is used, the positioning of the holes can be performed in 2.O ms. The positioning time for drilling 0 holes is (1 0, 0 0 0-1) X 2.0 / 100 0 = 1 9.998 seconds. When 10 shots are injected into each hole at 40 Hz from one side, (10-1) Z40X10, 000 + 19.998 = 2269.998 seconds Becomes This value is the minimum processing time excluding the reversal time in the method of reversing the substrate IS. Therefore, it actually takes a longer time. On the other hand, when processing both sides at the same time, there is no need for time to reverse, and only five shots are required for each side, so 2 2 6 9.99 9 8/2 = 1 1 3 4.9 It takes 99 seconds, and the processing time is reduced by half.
実施の形態 5. Embodiment 5.
被加工物の加工対象面にビームを直接照射した場合、 条件によっては 表面の穴形状が歪になる。 例えば、 通常レーザでプリント基板の穴開け 加工を行う場合には複数ショッ 卜投入するが、 特に炭酸ガスレーザの場 合には、 加工時間短縮のためにガルバノスキャナを用いる場合が多い。 このような装置は高速操作するために振動が発生しやすく、 レーザビー ム照射による基板への穴開け加工に於いては、 図 1 2に示すように、 わ ずかな振動であっても図 1 2の左半分に示す第 1 回目のショッ トと、 右 半分に示す第 2回目のショッ 卜との間でのビームの位置ずれの原因とな リ、 表面の加工穴の形状がいびつ （歪） となると共に第 1 回目のショッ 卜による穴と、 第 2回目のショッ トによる穴との間にずれが生ずること になる。 表面の穴形状が歪であると、 めっき後に或る部分のみに応力が 集中し、 そこから破断する可能性がある。 When the beam is directly applied to the surface to be processed of the workpiece, the hole shape on the surface may be distorted depending on the conditions. For example, when a hole is drilled in a printed circuit board with a laser, a plurality of shots are usually taken. In the case of a carbon dioxide laser in particular, a galvano scanner is often used to shorten the processing time. Such an apparatus is susceptible to vibrations due to high-speed operation. In drilling holes in a substrate by laser beam irradiation, as shown in FIG. The first shot shown in the left half of the figure and the second shot shown in the right half caused beam misalignment, and the shape of the machined hole on the surface was distorted (distorted). At the same time, there will be a gap between the hole from the first shot and the hole from the second shot. If the hole shape on the surface is distorted, stress will be applied only to certain parts after plating. It can concentrate and break from there.
図 1 3には本発明の加工方法を示す。 即ち、 加工する基板 3の表面に 薄膜状のポリエチレン等のレーザエネルギを吸収できる樹脂フィルム 1 2を貼り、 その上からレーザビーム 1 による照射をして穴開け加工を行 う。 このように表面に樹脂フイルム 1 2を貼った状態で加工すると、 図 1 3の左半分および図 1 3の右半分に示すように振動等の位置ずれの影 響を受けるのはフィルム 1 2だけで実際の基板の絶縁層 3の加工穴は問 題がない。  FIG. 13 shows the processing method of the present invention. That is, a resin film 12 such as a thin-film polyethylene or the like that can absorb laser energy is attached to the surface of the substrate 3 to be processed, and a hole is formed by irradiating a laser beam 1 thereon. When processing is performed with the resin film 12 adhered to the surface in this way, as shown in the left half of Fig. 13 and the right half of Fig. 13, only film 12 is affected by displacement such as vibration. Therefore, there is no problem with the holes formed in the insulating layer 3 of the actual board.
このようにしてフィルム 1 2を貼っていない基板とフイルム 1 2を 貼った基板に穴加工を行った場合の表面穴径の真円度のばらつきを測定 した結果を図 1 4のグラフに示す。 被加工材はエポキシ （厚み t 5 0 m ) で φ 1 0 0 μ mの穴加工である。 加工条件は、 1 パルス当たリのェ ネルギを 2 m J、 周波数 1 O H zとし 2ショッ ト投入している。 真円度 は （短径 長径 X 1 0 0 ) とし、 測定はフィルムを貼っていない基板は 加工直後に、 フィルムを貼っている基板はフィルムを剥がした後に各 2 5個の穴について測定した。 図 1 4から明らかな通り、 フィルム 1 2を 貼ってある基板の穴の真円度は高く、 また、 ばらつきも少ない。  FIG. 14 is a graph showing the results of measuring the variation in the roundness of the surface hole diameter when holes were formed on the substrate on which the film 12 was not bonded and the substrate on which the film 12 was bonded. The material to be processed is a hole with a diameter of φ100 μm made of epoxy (thickness t 50 m). The processing conditions were 2 shots at 2 mJ of energy per pulse and 1 shot at a frequency of 1 Hz. The roundness was (small diameter long diameter X 100), and the measurement was performed immediately after processing on the substrate without the film, and on the 25 holes each after peeling the film on the substrate with the film. As is clear from FIG. 14, the roundness of the hole of the substrate on which the film 12 is stuck is high and the variation is small.
なお、 既に実施の形態 3において示したように、 レーザビーム 1 で基 板 I Sの片面から穴加工を行うと穴の内壁面は亍ーパ状となって、 亍ー パの先端部では穴径が小さくなる。 そのため、 この加工現象によリ穴径 が小さくなることと、 フィルム 1 2を貼った基板 I Sの穴の真円度が高 いこととを合わせることで真円度の高い微細穴加工が可能となる。 図 1 5のグラフはフィルム 1 2の厚みと基板 I S表面での穴径との関係を示 している。 被加工材はエポキシ樹脂厚み 3 0 mの基板 1 2である。 加 ェ条件は 1 パルス当たりのエネルギ 1 m J、 周波数 1 0 H Zとし、 フィ ルム 1 2の表面での穴径が ψ 8 0 A< mとなるようにした。 また、 ショッ ト数は内層銅箔まで加工が達するようにフィルム 1 2の厚みに合わせ変 化させた。 このグラフから明らかな通りフィルム 1 2が厚くなると基板 表面の穴径が小さくなる傾向になる。 産置上 ffi可能性 As already described in the third embodiment, when a hole is drilled from one side of the substrate IS with the laser beam 1, the inner wall surface of the hole becomes a paper shape, and the hole diameter is formed at the tip of the paper. Becomes smaller. Therefore, by combining the reduction of the hole diameter due to this processing phenomenon with the high roundness of the hole of the substrate IS on which the film 12 is attached, it is possible to form a fine hole with high roundness. Become. The graph of FIG. 15 shows the relationship between the thickness of the film 12 and the hole diameter on the surface of the substrate IS. The workpiece is a substrate 12 having an epoxy resin thickness of 30 m. Energy 1 m J per pressurizing E condition 1 pulse, frequency 1 0 and H Z, the hole diameter at the surface of Fi Lum 1 2 was set to be ψ 8 0 A <m. Also, The number was changed according to the thickness of the film 12 so that the processing reached the inner layer copper foil. As is clear from this graph, when the film 12 becomes thicker, the hole diameter on the substrate surface tends to become smaller. Possibility of ffi
本発明のレーザ加工方法は、 絶縁層と、 この絶縁層上に設けられた銅 層とを備えた基板にレーザビームにより穴開け加工を行う レーザ加工方 法において、 基板上の穴を明けるべき位置にある銅層を選択的にエッチ ングによリ除去して、 絶縁層に開けるべき穴よリも大きな直径のエッチ ング穴を銅層に形成して絶縁層を露出させ、 エッチング穴から露出した 絶縁層に開けるべき穴に対応する直径のレーザビームを照射して、 絶縁 層に穴明けを行うレーザ加工法である。 この方法ならば、 加工性は絶縁 基板に対してレーザ加工する場合と同等でありながらパターンのピール 強度は銅張り基板と同等の値を得ることが可能である。  The laser processing method according to the present invention is directed to a laser processing method in which a substrate provided with an insulating layer and a copper layer provided on the insulating layer is drilled by a laser beam. The copper layer is selectively removed by etching, and an etching hole having a diameter larger than the hole to be formed in the insulating layer is formed in the copper layer to expose the insulating layer, which is then exposed from the etching hole. This is a laser processing method that irradiates a laser beam with a diameter corresponding to the hole to be formed in the insulating layer to make a hole in the insulating layer. With this method, it is possible to obtain a pattern peel strength equivalent to that of a copper-clad substrate, while maintaining the workability equivalent to that of laser processing of an insulating substrate.
また、 本発明は、 被加工物にレーザビームを照射して被加工物に穴明 け加工を行う加工方法において、 被加工物の穴開け加工位置に被加工物 の両面からレーザビームを照射することを特徴とするレーザ加工法でも ある。 このため、 スルーホール加工時の亍ーパ発生が抑制され、 ス ト レー卜に近い穴加工が可能である。  The present invention also provides a method for piercing a workpiece by irradiating the workpiece with a laser beam, wherein the laser beam is radiated from both sides of the workpiece to a boring position of the workpiece. This is also a laser processing method characterized by this. For this reason, the generation of paper at the time of through-hole processing is suppressed, and a hole processing close to a straight hole can be performed.
また、 本発明は、 被加工物にレーザビームを照射して被加工物の材料 の除去加工を行う加工方法において、 被加工物の両面の除去加工位置に 対応する位置にレーザビームを照射して、 除去加工によリ発生した異物 を被加工物から取り除く ことを特徴とするレーザ加工法でもある。 この 方法により、 後工程での不良発生率を抑制できる。  The present invention also provides a processing method for irradiating a workpiece with a laser beam to remove a material of the workpiece, comprising irradiating the workpiece with a laser beam at a position corresponding to a removal processing position on both surfaces of the workpiece. In addition, the laser processing method is characterized in that foreign matter generated by the removal processing is removed from the workpiece. With this method, the rate of occurrence of defects in the subsequent steps can be suppressed.
また、 被加工物にレーザビームを照射して被加工物の材料の除去加工 を行う加工方法において、 被加工物の両面の除去加工位置に対応する位 置にレーザビームを同時にあるいは時間差を設けて照射することを特徴 とするレーザ加工法でもある。 このように、 被加工物の表裏二方向から 同時あるいはわずかに時間差を設けて加工するため、 高品位でかつ加工 時間の短い加工が可能である。 Further, in a processing method for irradiating a workpiece with a laser beam to remove a material of the workpiece, a position corresponding to a removal processing position on both surfaces of the workpiece. The laser processing method is also characterized in that the laser beams are irradiated simultaneously or with a time lag on the device. As described above, since the workpiece is machined simultaneously or slightly with a time lag from the front and back sides in two directions, high quality and short machining time can be achieved.
更に、 本発明は、 被加工物にレーザビームを照射して被加工物の材料 の除去加工を行う加工方法において、 被加工物の除去加工位置に対応す る位置に後工程にて剥離可能な薄膜層あるいは板材を密着させ、 除去加 ェ位置にレーザビームを照射して、 薄膜層を除去した後に被加工物の材 料の除去加工を行うことを特徴とするレーザ加工法である。 このように 被加工物の表面に薄膜を密着させた上で加工するため、 加工対象面上の 穴形状のばらつきを抑制することが可能であり、 また、 基板に微細な穴 を形成することが可能である。  Further, the present invention provides a processing method for irradiating a workpiece with a laser beam to remove a material of the workpiece, wherein the workpiece can be peeled off in a post-process at a position corresponding to the removal processing position of the workpiece. This laser processing method is characterized in that a thin film layer or a plate material is brought into close contact, a laser beam is applied to a position to be removed, and the thin film layer is removed. As described above, since the thin film is adhered to the surface of the workpiece to be processed, the variation of the hole shape on the surface to be processed can be suppressed, and fine holes can be formed in the substrate. It is possible.

Claims

請求の範囲 The scope of the claims
1 . 絶縁層と、 この絶縁層上に設けられた銅層とを備えた基板にレーザ ビームにより穴開け加工を行う レーザ加工方法において、 上記基板上の 穴を明けるべき位置にある銅層を選択的にエッチングによリ除去して、 開けるべき穴よリも大きな直径のエッチング穴を銅層に形成して上記絶 縁層を露出させ、 上記エッチング穴から露出した上記絶縁層に上記開け るべき穴に対応する直径のレーザビームを照射して、 上記絶縁層に穴明 けを行う レーザ加工法。 1. In a laser processing method in which a substrate provided with an insulating layer and a copper layer provided on the insulating layer is drilled by a laser beam, a copper layer in a position where a hole is to be formed on the substrate is selected. An etching hole having a diameter larger than that of the hole to be formed is formed in the copper layer to expose the insulating layer, and the opening is formed in the insulating layer exposed from the etching hole. A laser processing method that irradiates a laser beam with a diameter corresponding to the hole to make a hole in the insulating layer.
2 . 被加工物にレーザビームを照射して被加工物に穴明け加工を行う加 ェ方法において、 被加工物の穴開け加工位置に上記被加工物の両面から レーザビームを照射することを特徴とする請求項 1 記載のレーザ加工法 2. A method for piercing a workpiece by irradiating the workpiece with a laser beam, wherein the laser beam is radiated from both sides of the workpiece to a drilling position of the workpiece. The laser processing method according to claim 1
3 . 被加工物にレーザビームを照射して被加工物の材料の除去加工を行 う加工方法において、 被加工物の両面の除去加工位置に対応する位置に レーザビームを照射して、 上記除去加工により発生した異物を上記被加 ェ物から取り除くことを特徴とするレーザ加工法。 3. In the processing method of irradiating the workpiece with a laser beam to remove the material of the workpiece, irradiating the laser beam to positions corresponding to the removal processing positions on both surfaces of the workpiece, and performing the removal. A laser processing method characterized in that foreign matter generated by processing is removed from the workpiece.
4 . 被加工物にレーザビームを照射して被加工物の材料の除去加工を行 う加工方法において、 被加工物の両面の除去加工位置に対応する位置に レーザビームを同時にあるいは時間差を設けて照射することを特徴とす るレーザ加工法。 4. In the processing method of removing the material of the workpiece by irradiating the workpiece with the laser beam, the laser beam is simultaneously or at a time difference provided at the positions corresponding to the removal processing positions on both surfaces of the workpiece. A laser processing method characterized by irradiation.
5 . 被加工物にレーザビームを照射して被加工物の材料の除去加工を行 う加工方法において、 上記被加工物の上記除去加工位置に対応する位置 に後工程にて剥離可能な薄膜層あるいは板材を密着させ、 上記除去加工 位置にレーザビームを照射して、 上記薄膜層を除去した後に上記被加工 物の材料の除去加工を行うことを特徴とするレーザ加工法。 5. In a processing method for irradiating a workpiece with a laser beam to remove a material of the workpiece, a position corresponding to the removal processing position of the workpiece. In addition, a thin film layer or a plate material that can be peeled off in a post-process is brought into close contact with the substrate, and a laser beam is applied to the removal processing position to remove the thin film layer and then remove the material of the workpiece. Laser processing method.
PCT/JP1998/002239 1998-05-21 1998-05-21 Laser machining method WO1999059761A1 (en)

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US8268182B2 (en) 2006-05-20 2012-09-18 Sumitomo Electric Industries, Ltd. Product having through-hole and laser processing method
JP2018129548A (en) * 2007-11-22 2018-08-16 味の素株式会社 Method for manufacturing multilayer printed wiring board

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JPH04250687A (en) * 1991-01-26 1992-09-07 Nippon Mektron Ltd Manufacture of flexible circuit board
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JPH03190186A (en) * 1989-12-19 1991-08-20 Brother Ind Ltd Manufacture of circuit board
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