JP7152729B2 - Manufacturing method of laser processed product - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a laser-processed product, and a laminate manufactured by the method for manufacturing a laser-processed product.

A resin substrate including glass cloth such as a glass epoxy substrate is subjected to processing such as cutting and formation of through holes for various purposes. Such substrate processing has conventionally been performed by mechanical processing using blades, drills, routers, etc., but in recent years laser processing is sometimes used. For example, in Patent Document 1, after affixing a protective sheet having a light transmittance of less than 50% in the laser light absorption region to the surface on which the laser light is incident, a workpiece such as a glass epoxy substrate is subjected to laser processing. It is disclosed to

Japanese Patent Application Laid-Open No. 2005-186110

However, in the conventional laser processing method, when the output of laser light is increased, processing quality may deteriorate.

Accordingly, an object of the present invention is to provide a method for manufacturing a laser-processed product with high processing quality, and a laser-processed product with high processing quality.

A method for manufacturing a laser-processed product according to one embodiment of the present invention prepares a laminate in which a light-transmitting resin film, a first metal layer, a substrate, a second metal layer, and a light-absorbing resin film are laminated in this order. and processing the laminate by irradiating the laminate with a laser beam from the light-absorbing resin film side, wherein the substrate has a coefficient of linear expansion of 8×10 ⁻⁶ /° C. or less. A resin composite material having a thickness of 200 μm or more, which contains a plurality of glass cloth layers of and the resin ratio is 40 to 70% by mass, and the transmittance of the light of the oscillation wavelength of the laser light of the light-transmitting resin film is , is 75% or more, the absorption rate of the light of the oscillation wavelength of the laser light of the light-absorbing resin film is 30% or more, and the laser light has an output of 10 to 200 W and a repetition frequency of 1000 to 5000 kHz. is a pulsed laser beam, scanned at a speed of 1000 to 5000 mm / s in the process of processing the laminate, and the area ratio of the glass cloth on the processed surface of the laminate formed in the process of processing the laminate is in the range of 120 to 180% with respect to the area ratio of the glass cloth on the processed surface after removing the melt-deformed portion of the glass cloth on the processed surface by polishing .

Further, a method for manufacturing a laser-processed product according to an embodiment of the present invention includes the steps of preparing a laminate in which a first metal layer, a base material and a second metal layer are laminated in this order; and processing the laminate by irradiating light, wherein the base material is a glass cloth having a linear expansion coefficient of 8×10 ⁻⁶ /° C. or less and a thickness of 30 to 95 μm, and a thickness of 5 to 95 μm. A resin composite material having a thickness of 200 μm or more in which resin layers of 50 μm are alternately laminated , wherein the laser beam is a pulsed laser beam having an output of 10 to 200 W and a repetition frequency of 1000 to 5000 kHz, In the process of processing the laminate, scanning is performed at a speed of 1000 to 5000 mm/s, and the area ratio of the glass cloth on the processed surface of the laminate formed in the process of processing the laminate is the glass on the processed surface. It is in the range of 120 to 180% with respect to the area ratio of the glass cloth on the processed surface after removing the melt-deformed portion of the cloth by polishing .

Accordingly, it is possible to provide a method for manufacturing a laser-processed product with high processing quality and a laser-processed product with high processing quality.

1 is a schematic cross-sectional view showing the structure of a substrate according to an embodiment of the invention; FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is typical sectional drawing which shows the structure of the laminated body which concerns on one embodiment of this invention. FIG. 4 is a schematic cross-sectional view showing the configuration of a laminate according to another embodiment of the invention; FIG. 2B is a schematic diagram for explaining an example of a process of forming elongated holes in the laminate shown in FIG. 2B; FIG. 2B is a schematic diagram for explaining an example of a process of forming elongated holes in the laminate shown in FIG. 2B; FIG. 2B is a schematic diagram for explaining an example of a process of forming elongated holes in the laminate shown in FIG. 2B; FIG. 4 is a schematic diagram showing a processed surface of a base material when processed under appropriate conditions. FIG. 4 is a schematic diagram showing a processed surface of a base material when processed under inappropriate conditions; FIG. 4 is a schematic view showing the processed surface of the base material after removing the melt-deformed portion of the glass cloth by polishing. 4 is a photograph of a first region of a processed surface after laser processing; 4 is a photograph of a second region of the processed surface after laser processing; 4 is a photograph of a third region of the processed surface after laser processing; It is a photograph of the 4th area|region of the processed surface after laser processing.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

1. 1. Base Material and Laminate FIG. 1 is a schematic cross-sectional view showing the structure of a base material 100 according to an embodiment of the present invention. As shown in FIG. 1, the substrate 100 is a resin composite material having a base resin 110 and multiple layers of glass cloth 120 . In this embodiment, resin layer 112 exists between glass cloths 120 . That is, the glass cloth 120 and the resin layer 112 are alternately laminated.

The type of resin 110 is not particularly limited. Examples of resin 110 include epoxy resins, polyimide resins, polyethylene terephthalate resins, polyethylene naphthalate resins, bismaleimide triazine resins, phenolic resins, silicone resins, modified silicone resins, epoxy-modified silicone resins, polyphenylene ether resins, liquid crystal polymer resins and Combinations of these are included. The thickness of the resin layer 112 is not particularly limited, but is, for example, within the range of 5 to 50 μm, preferably 15 to 45 μm.

In order to reduce the coefficient of linear expansion of the substrate 100, a glass cloth 120 having a coefficient of linear expansion of 8×10 ⁻⁶ /° C. or less is placed inside the substrate 100 . In addition, in order not to reduce the laser processability of the substrate 100, a plurality of layers of thin glass cloth 120 are arranged in the substrate 100 instead of placing one layer of thick glass cloth. By doing so, it is possible to suppress the amount of glass that leads to deterioration of the laser processability while realizing the purpose of reducing the coefficient of linear expansion of the base material 100 . The number of glass cloths 120 is not particularly limited as long as it is plural, and is appropriately set according to the thickness of the glass cloths 120 and the desired coefficient of linear expansion of the substrate 100 . From the viewpoint of laser processability, the number of glass cloths 120 is preferably three or more. In the example shown in FIG. 1, the substrate 100 has three layers of glass cloth 120 . In addition, the thickness of the glass cloth 120 is preferably thin to some extent from the viewpoint of not reducing the laser processability, for example, 30 to 95 μm, preferably 30 to 60 μm.

The thickness of base material 100 is determined by the respective thicknesses and numbers of resin layer 112 and glass cloth 120, and is 200 μm or more in the present embodiment. Although the upper limit of the thickness of the base material 100 is not particularly limited, it is, for example, 500 μm. Also, the ratio of the resin 110 in the base material 100 is 40 to 70% by mass. If the proportion of the glass cloth 120 in the substrate 100 is too large, the laser processability of the substrate 100 may deteriorate. On the other hand, if the proportion of the glass cloth 120 in the base material 100 is too small, the coefficient of linear expansion of the base material 100 may not be sufficiently reduced.

This base material 100 is laser-processed in the state of a laminate in which other layers are laminated on both sides thereof. 2A and 2B are schematic cross-sectional views showing the structure of the laminate according to the embodiment of the invention. In a layered product 200A shown in FIG. 2A, a first metal layer 220, a substrate 100 and a second metal layer 230 are layered in this order. In the laminated body 200B shown in FIG. 2B, a light-transmitting resin film 210, a first metal layer 220, a substrate 100, a second metal layer 230 and a light-absorbing resin film 240 are laminated in this order. The first metal layer 220, the substrate 100 and the second metal layer 230 shown in FIG. 2A are also referred to as a metal-clad laminate. As shown in FIG. 2A, light-transmitting resin film 210 and light-absorbing resin film 240 may not be laminated, but from the viewpoint of improving processing quality, as shown in FIG. 210 and light absorbing resin film 240 are also preferably laminated.

Light transmissive resin film 210 holds substrate 100 (and first metal layer 220 and second metal layer 230) during laser processing. For example, when part of the base material 100 is hollowed out by laser processing, not only the hollowed out part (the part that remains as the base material 100) but also the hollowed out part (the part that becomes the through hole) is held by the light-transmitting resin film 210. be done. As a result, it is possible to prevent part of the base material 100 from coming off or moving during laser processing. The light-transmitting resin film 210 is usually peeled off after laser processing. From the viewpoint of achieving the above object, it is preferable that the light-transmitting resin film 210 is not processed together with the base material 100 during laser processing. Therefore, the transmittance of the light-transmitting resin film 210 with respect to the light of the oscillation wavelength of the laser beam irradiated during laser processing is preferably 75% or more, more preferably 80% or more.

The type of resin that constitutes the light-transmitting resin film 210 is not particularly limited, and can be appropriately selected from resins that constitute known resin films. Examples of the resin constituting the light-transmitting resin film 210 include olefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymer; ethylene-vinyl acetate copolymer, ionomer resin, ethylene-(meth)acrylic acid copolymer; Copolymers with ethylene as a monomer component, such as ethylene-(meth)acrylic acid ester (random and alternating) copolymers; polyesters such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate; acrylic resins; Vinyl; polyurethane; polycarbonate; polyphenylene sulfide; amide resins such as polyamide (nylon) and wholly aromatic polyamide (aramid); polyether ether ketone; polyimide; cellulose resins; silicone resins; fluorine resins and the like. The resin film may be a non-stretched film or a uniaxially or biaxially stretched film. Also, the light-transmitting resin film 210 may be a laminate of the above resin films. The light-transmitting resin film 210 may further contain various additives.

The thickness of the light-transmitting resin film 210 is not particularly limited, and can be appropriately selected according to the required strength, flexibility, and the like. The thickness of the light-transmitting resin film 210 is, for example, 1-1000 μm, preferably 10-500 μm, more preferably 20-300 μm.

The light-transmitting resin film 210 is usually adhered to the first metal layer 220 via an adhesive. The type of adhesive is not particularly limited, and can be appropriately selected from known adhesives. Examples of adhesives include acrylic adhesives, rubber adhesives, vinyl alkyl ether adhesives, silicone adhesives, polyester adhesives, polyamide adhesives, urethane adhesives, fluorine adhesives, and styrene adhesives. - Includes diene block copolymer adhesives. Also, the adhesive may be a radiation-curable adhesive, an energy ray-curable adhesive, a thermally expandable adhesive, or the like. Furthermore, the adhesive may be used alone or in combination of two or more.

A known dicing tape can also be used as such a light-transmitting resin film 210 .

Both the first metal layer 220 and the second metal layer 230 are layers made of a metal or an alloy. For example, when first metal layer 220, base material 100 and second metal layer 230 (laminate 200A) are used as a metal-clad laminate for manufacturing a printed wiring board, these metal layers can serve as electrical wiring. .

The types of metals or alloys forming first metal layer 220 and second metal layer 230 are not particularly limited. Examples of metals or alloys forming first metal layer 220 and second metal layer 230 include copper, silver, gold, aluminum, and alloys containing these metals as main components. From the viewpoint of conductivity, workability by etching, and cost, the metal or alloy forming the first metal layer 220 and the second metal layer 230 is preferably a copper alloy containing copper as a main component, or copper. The composition of the first metal layer 220 and the composition of the second metal layer 230 may be the same or different. Also, each of the first metal layer 220 and the second metal layer 230 may be composed of one layer, or may be composed of two or more layers. The thickness of each of the first metal layer 220 and the second metal layer 230 is not particularly limited, but is, for example, 1 to 15 μm. The thickness of the first metal layer 220 and the thickness of the second metal layer 230 may be the same or different. The method of forming the first metal layer 220 and the second metal layer 230 is not particularly limited. For example, by laminating a plurality of prepregs obtained by impregnating a glass cloth 120 with varnish, placing a metal foil on each side of the obtained laminate, and applying heat and pressure, the first A laminate 200A consisting of the metal layer 220, the substrate 100 and the second metal layer 230 can be manufactured.

Further, between the first metal layer 220 and the base material 100 and/or between the second metal layer 230 and the base material 100, other metal layers are arranged for the purpose of improving adhesion and preventing migration. may be Examples of such a metal layer include a nickel layer, a chromium layer, a nickel-chromium alloy layer, and the like, each having a thickness of about several hundred nanometers.

The light absorbing resin film 240 protects the surface of the second metal layer 230 during laser processing. For example, when the substrate 100 (as well as the first metal layer 220 and the second metal layer 230) is subjected to laser processing, debris and dross adhere to the surface of the second metal layer 230 that is irradiated with laser light. The light-absorbing resin film 240 prevents such debris and dross from adhering to the second metal layer 230 . The light-absorbing resin film 240 is usually peeled off after laser processing.

Light absorbing resin film 240 is preferably processed together with substrate 100 (and first metal layer 220 and second metal layer 230) during laser processing. As described above, in the laminate 200B, the light-transmitting resin film 210 is not substantially processed during laser processing. Therefore, if the light-absorbing resin film 240 is also not substantially processed, the decomposition product of the base material 100 (and the first metal layer 220 and the second metal layer 230) generated during laser processing will be outside the laminate 200B. It cannot move and sticks to the working surface of the substrate 100 (as well as the first metal layer 220 and the second metal layer 230). Adhesion of such decomposition products to the processing surface leads to deterioration of processing quality. By processing the light-absorbing resin film 240 by laser processing, the decomposition products are scattered from the processed portion of the light-absorbing resin film 240 to the outside of the laminate 200B, so that the adhesion of the decomposition products to the processed surface is suppressed. be. Some of the decomposed substances scattered in this way adhere to the light-absorbing resin film 240 , but do not adhere to the second metal layer 230 protected by the light-absorbing resin film 240 . From the viewpoint of achieving the above object, the absorbance of the light-absorbing resin film 240 with respect to the light of the oscillation wavelength of the laser beam irradiated during laser processing is preferably 30% or more, more preferably 50% or more. more preferred.

The type of resin forming the light-absorbing resin film 240 is not particularly limited, and can be appropriately selected from resins forming known resin films. Examples of the resin constituting the light-absorbing resin film 240 include olefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymer; ethylene-vinyl acetate copolymer, ionomer resin, ethylene-(meth)acrylic acid copolymer; Copolymers with ethylene as a monomer component, such as ethylene-(meth)acrylic acid ester (random and alternating) copolymers; polyesters such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate; acrylic resins; Vinyl; polyurethane; polycarbonate; polyphenylene sulfide; amide resins such as polyamide (nylon) and wholly aromatic polyamide (aramid); polyether ether ketone; polyimide; cellulose resins; silicone resins; fluorine resins and the like. Among these, aromatic resins such as polyimide, polyethylene naphthalate, and polycarbonate are preferred. The resin film may be a non-stretched film or a uniaxially or biaxially stretched film. Also, the light absorbing resin film 240 may be a laminate of the above resin films. The light-absorbing resin film 240 may further contain various additives for the purpose of increasing the light absorption rate. Examples of additives for increasing light absorptance include pigments, dyes, pigments, metal fine particles, inorganic fine particles, and the like.

The thickness of the light-absorbing resin film 240 is not particularly limited, and can be appropriately selected according to the required strength, flexibility, and the like. The thickness of the light-absorbing resin film 240 is, for example, 1-500 μm, preferably 2-300 μm, more preferably 5-250 μm.

The light-absorbing resin film 240 is usually adhered to the second metal layer 230 via an adhesive. The type of adhesive is not particularly limited, and can be appropriately selected from known adhesives. Examples of adhesives include acrylic adhesives, rubber adhesives, vinyl alkyl ether adhesives, silicone adhesives, polyester adhesives, polyamide adhesives, urethane adhesives, fluorine adhesives, and styrene adhesives. - Includes diene block copolymer adhesives. Also, the adhesive may be a radiation-curable adhesive, an energy ray-curable adhesive, a thermally expandable adhesive, or the like. Furthermore, the adhesive may be used alone or in combination of two or more.

It is also possible to use a known surface protection tape as such a light absorbing resin film 240 .

2. Method for Manufacturing Laser-Processed Product The method for manufacturing a laser-processed product according to the present embodiment includes a first step of preparing the laminate 200A or the laminate 200B, and irradiating the laminate 200A or the laminate 200B with a laser beam. and a second step of processing the laminate 200A or the laminate 200B. Moreover, the method for manufacturing a laser-processed product according to the present embodiment may further include, as an optional step, a third step of plating the processed surface formed in the second step. Each step will be described below.

(First step)
In the first step, the layered body 200A or layered body 200B is prepared as an object to be processed. The laminated body 200A and the laminated body 200B may be purchased and prepared, or may be manufactured by oneself.

As described above, for example, a plurality of prepregs obtained by impregnating the glass cloth 120 with varnish are laminated, one metal foil is placed on each side of the obtained laminate, and heated and pressed. , a laminate 200A (see FIG. 2A) having the first metal layer 220, the substrate 100 and the second metal layer 230 can be produced. The light-transmitting resin film 210 is attached to the first metal layer 220 of the laminate 200A via an adhesive, and the light-absorbing resin film 240 is attached to the second metal layer 230 of the laminate 200A via an adhesive. , the light-transmitting resin film 210, the first metal layer 220, the substrate 100, the second metal layer 230 and the light-absorbing resin film 240 (see FIG. 2B).

(Second step)
In the second step, the laminate 200A or the laminate 200B prepared in the first step is irradiated with a laser beam to process the laminate 200A or the laminate 200B. Specifically, when processing the layered product 200A, the layered product 200A is processed by irradiating the layered product 200A with a laser beam from the second metal layer 230 side. As a result, the first metal layer 220, the base material 100 and the second metal layer 230 are processed to form processed surfaces (new side surfaces). When processing the laminate 200B, the laminate 200B is processed by irradiating the laminate 200B with a laser beam from the light absorbing resin film 240 side. As a result, the first metal layer 220, the base material 100, the second metal layer 230, and the light-absorbing resin film 240 are processed to form processed surfaces (new side surfaces).

The processing mode in the second step is not particularly limited. For example, the laminated body 200A or the laminated body 200B may be cut by scanning the laser light along a straight line or a curved line. In this case, the machined surface is the newly formed cut surface. Alternatively, a laser beam may be scanned so as to surround a specific region to hollow out a specific region of the laminate 200A or the laminate 200B to form a through-hole of arbitrary size and shape. In this case, the machined surface is the inner surface of the newly formed through hole. In any case, the processed surface includes at least the cross section of the first metal layer 220, the cross section of the substrate 100 and the cross section of the second metal layer 230. In addition, the cross section of the base material 100 includes cross sections of the plurality of resin layers 112 and cross sections of the plurality of glass cloths 120 . As will be described later, the glass cloth 120 is melted and deformed by heat during laser processing on the processing surface.

3A to 3C are schematic diagrams for explaining an example of a process of forming elongated holes as through holes in the laminate 200B.

As shown in FIG. 3A, while irradiating the laminate 200B with the laser beam 300 from the light-absorbing resin film 240 side, the relative position of the focal point of the laser beam 300 and the laminate 200B is changed. At this time, the focal point of the laser beam 300 is located inside the base material 100 and is scanned over a plurality of circumferences along the planned outer edge line of the elongated hole to be formed. By scanning the laser light 300 multiple times in this way, as shown in FIG. 3B, grooves 310 are formed that extend from the surface of the light-absorbing resin film 240 to the surface of the first metal layer 220 on the light-transmitting resin film 210 side. and a slot 320 is formed. The width processed by the laser beam 300, that is, the width of the groove 310 is, for example, 10 to 30 μm. As described above, the light-absorbing resin film 240 is processed by the laser beam 300 , but the light-transmitting resin film 210 is substantially not processed by the laser beam 300 . Therefore, the groove 310 does not penetrate the light-transmitting resin film 210, and the portion surrounded by the groove 310 is held by the light-transmitting resin film 210 like the surroundings. Thus, the portion surrounded by groove 310 remains in slot 320, as shown in FIG. 3B.

After that, as shown in FIG. 3C, by peeling the light-transmitting resin film 210 from the first metal layer 220, the portion left in the slot 320 can be removed. Also, by peeling off the light-absorbing resin film 240 with debris, dross, etc., from the second metal layer 230, the clean second metal layer 230 can be exposed.

In the example of FIGS. 3A to 3C, one long hole is formed, but the shape and number of through holes are not particularly limited. For example, a plurality of long holes may be formed in one laminate 200A or laminate 200B such that the major axes thereof are parallel to each other. In this specification, the term “long hole” refers to a through hole whose opening has a different length in the first direction and a length in a direction orthogonal to the first direction. For example, the elongated hole is a through hole whose length in the longitudinal direction of the opening is at least twice the length in the widthwise direction, and preferably the length in the lengthwise direction of the opening is three times the length in the widthwise direction. More than twice as many through-holes. Of course, the shape of the opening of the through hole may be circular or rectangular, or may be a more complicated shape.

If the laminates 200A and 200B are appropriately laser-processed as described above, the difference between the longitudinal size of one opening of the through hole (e.g., long hole) and the longitudinal size of the other opening is 20 μm or less, and the difference between the widthwise size of one opening of the through-hole (for example, long hole) and the widthwise size of the other opening can also be set to 20 μm or less. That is, the through-holes can be formed so that the processed surfaces are substantially perpendicular to the plane directions of the laminates 200A and 200B.

Also, the position of the focal point of the laser beam 300 is not limited to the position shown in FIG. 3A. For example, the focal point of the laser beam 300 may be scanned on the planned outer edge line of the long hole 320, or may be scanned inside the planned outer edge line substantially parallel to the planned outer edge line. In addition, the position (depth) of the focal point of the laser beam 300 in the thickness direction of the laminates 200A and 200B may be constant regardless of the progress of processing, or may change according to the progress of processing. You may

The type of laser light 300 is not particularly limited. Examples of the laser light 300 include continuous wave (CW) laser light, laser light obtained by modulating continuous wave laser light (CWM laser light), pulsed laser light, and the like. From the viewpoint of processing quality, the laser beam 300 is preferably a pulsed laser beam. Also, the wavelength of the laser light 300 is not particularly limited as long as the grooves 310 can be appropriately formed in the laminates 200A and 200B. From the viewpoint of suppressing the occurrence of undesirable thermal damage in the processed portion of the base material 100, the wavelength of the laser beam 300 is preferably within the range of 250 to 2000 nm, more preferably within the range of 250 to 1500 nm. more preferred. Moreover, when the laser beam 300 is a pulsed laser beam, the pulse width of the laser beam 300 is not particularly limited as long as the grooves 310 can be appropriately formed in the laminates 200A and 200B. From the viewpoint of improving processing quality, the pulse width of the laser beam 300 is preferably within the range of 10 picoseconds to 100 nanoseconds. For example, laser light 300 is picosecond pulsed laser light with an oscillation wavelength of 355 nm or 1064 nm.

When the laser light 300 is pulsed laser light, the output power and repetition frequency of the pulsed laser light are not particularly limited as long as the grooves 310 can be appropriately formed in the laminates 200A and 200B. From the viewpoint of increasing the processing speed, the output of the pulsed laser light is preferably 10 to 50W, but may be 10 to 200W. From the viewpoint of improving processing quality, the repetition frequency of the pulsed laser light is preferably 1000 to 5000 kHz.

Although the scanning speed of the laser beam 300 is not particularly limited, the scanning speed of the laser beam 300 is preferably 1000 to 5000 mm/s from the viewpoint of achieving both processing speed and processing quality. In addition, the number of times of scanning the laser beam 300 per one processed portion is not particularly limited as long as the groove 310 with a desired depth can be formed. can be set as appropriate.

In the example shown in FIGS. 3A to 3C, both the inner side surface of the groove 310 and the inner side surface of the long hole 320 correspond to the machined surface. During laser processing, the temperature of the processed portion temporarily rises, so the resin layer 112 and the glass cloth 120 of the substrate 100 are also affected by the high temperature. Specifically, when observing the processed surface of the base material 100, a part of the resin layer 112 is discolored, and the glass cloth 120 is melted and deformed. From these points, when observing the processed surfaces (side surfaces) of the laminates 200A and 200B, it is possible to determine whether the surfaces are formed by laser processing or by other methods (for example, mechanical processing using a blade or the like). It can be distinguished whether it was done or not.

In addition, in the laminates 200A and 200B according to the present embodiment, the glass cloth 120 is thinned instead of arranging the glass cloth 120 in a plurality of layers. can be processed. Therefore, if processing is performed under appropriate conditions, the resin layer 112 will not be severely scorched on the processed surface, and the glass cloth 120 will not be melted and deformed to the extent that the original shape cannot be recognized.

Even when processed under appropriate conditions, as shown in FIG. melts and deforms. However, if processed under appropriate conditions, the molten glass will not cover most of the resin layer 112 as shown in FIG. 4B. If the melt-deformed portions of the glass cloth on these processed surfaces are removed by polishing with a file or the like, the original position of the glass cloth 120 can be confirmed as shown in FIG. 4C. When processed under appropriate conditions, the area ratio of the glass cloth on the processed surface after laser processing shown in FIG. 4A and the area ratio of the glass cloth after removing the melt-deformed portion of the glass cloth shown in FIG. 4C , does not change significantly. More specifically, the area ratio of the glass cloth on the processed surface after laser processing is 120 to 180% of the ratio of the area ratio of the glass cloth after polishing and removing only the melt-deformed portion of the glass cloth. within the range. The area ratio of the glass cloth on the processed surface can be calculated by image analysis of a photograph of the processed surface.

In addition, when the above method is processed under appropriate conditions, a smooth processed surface is formed as a whole. More specifically, the processed surface after laser processing has a maximum height roughness Rz conforming to JIS B0601:2013 (ISO 4287:1997) of 35 μm or less.

(Third step)
In the optional third step, the processed surface formed in the second step is plated. For example, when a through hole (long hole) is formed as shown in FIGS. 3A to 3C, the inner surface of the through hole is plated. By this step, the first metal layer 220 and the second metal layer 230 can be electrically connected via the plated layer on the inner side surface of the through hole.

The method of plating the processed surface is not particularly limited, and may be appropriately selected from known methods. Also, the type of metal to be plated is not particularly limited, and may be appropriately selected according to the purpose. For example, after applying electroless copper plating to the processed surface, further electrolytic copper plating can be applied to form a copper plating layer having a predetermined thickness on the processed surface.

In the laser-processed product manufactured by the above procedure, a dry film necessary for etching these metal layers is attached on the first metal layer 220 and/or the second metal layer 230. may

As described above, in the method for manufacturing a laser-processed product according to the present embodiment, the laminates 200A and 200B including the base material 100 having a plurality of layers of thin glass cloth 120 instead of a single thick glass cloth are processed. Therefore, it is possible to process the laminates 200A and 200B without excessively increasing the output of the laser beam. Therefore, the glass cloth is not excessively melted and deformed on the processed surface, and it is possible to provide a laser-processed product with high processing quality.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited by these examples.

As an object to be processed, a glass-epoxy copper-clad laminate was prepared by attaching copper foil (5 μm in thickness) to both sides of a glass-epoxy substrate (300 μm in thickness). In the glass epoxy copper-clad laminate, three layers of glass cloth (thickness: 90 μm, linear expansion coefficient: 3.5×10 ⁻⁶ /° C.) were arranged alternately with resin layers (thickness: 10 μm). . The proportion of resin in the glass-epoxy copper-clad laminate was 55% by mass.

A pulsed laser beam (wavelength: 355 nm, pulse width: 2 ns, output: 30 W) was applied to this glass-epoxy copper-clad laminate to form an oblong hole (length in the longitudinal direction: 3 mm, length in the lateral direction: 1.5 mm). 8 mm). Processing conditions are as follows. By "spot diameter" is meant a diameter in the range of light intensity up to ¹ /e2 with respect to the center.
Wavelength: 355nm
Pulse width: 2ns
Output: 30W
Pulse energy: 15 μJ
Repetition frequency: 2000 kHz
Position of converging point: 100 μm from the surface of the copper layer on the front side
Spot diameter on the surface of the copper foil on the front side: 10.5 μm
Fluence on the surface of the front copper foil: 18 J/cm ²
Spot diameter at focal point: 5.6 μm
Fluence at focal point: 61 J/cm ²
Scanning speed: 2000mm/s
Scanning laps: 60 laps

The inner surface (processed surface) along the longitudinal direction of the formed elongated hole was observed to measure the area ratio of the glass cloth on the processed surface. Thereafter, the processed surface was lightly ground with a file to remove the melted and deformed portion of the glass cloth, and the area ratio of the glass cloth on the processed surface was measured again.

FIG. 5A is a photograph of the first region of the processed surface after laser processing. FIG. 5B is a photograph of the second region of the processed surface after laser processing. FIG. 5C is a photograph of the third region of the processed surface after laser processing. FIG. 5D is a photograph of the fourth region of the processed surface after laser processing.

As shown in these figures, on each processed surface, a portion of the glass cloth was melted, but the amount of deformation was not large. Further, in any region, the area ratio of the glass cloth on the processed surface after laser processing is the ratio of the area ratio of the glass cloth on the processed surface after removing the melted and deformed portion of the glass cloth on the processed surface by polishing. It was in the range of 120-180% with respect to When a resin substrate containing glass cloth is machined using a blade or the like, the glass cloth does not substantially melt. does not change. That is, the area ratio of the glass cloth on the processed surface after machining is approximately 100% with respect to the ratio of the area ratio of the glass cloth on the processed surface after polishing and removing the end portion of the glass cloth on the processed surface. be.

A method for manufacturing a laser-processed product according to an embodiment of the present invention can be applied to, for example, the manufacture of semiconductor elements.

REFERENCE SIGNS LIST 100 base material 110 resin 112 resin layer 120 glass cloth 200A, 200B laminate 210 light-transmitting resin film 220 first metal layer 230 second metal layer 240 light-absorbing resin film 300 laser beam 310 groove 320 long hole

Claims (8)

preparing a laminate in which a light-transmitting resin film, a first metal layer, a substrate, a second metal layer and a light-absorbing resin film are laminated in this order;
and processing the laminate by irradiating the laminate with a laser beam from the light-absorbing resin film side,
The base material is a resin composite material having a thickness of 200 μm or more, which includes a plurality of layers of glass cloth having a linear expansion coefficient of 8×10 ⁻⁶ /° C. or less and a resin ratio of 40 to 70% by mass,
The transmittance of the light of the oscillation wavelength of the laser light of the light-transmitting resin film is 75% or more,
The light absorption rate of the light absorption resin film at the oscillation wavelength of the laser light is 30% or more ,
The laser beam is a pulse laser beam having an output of 10 to 200 W and a repetition frequency of 1000 to 5000 kHz, and is scanned at a speed of 1000 to 5000 mm / s in the step of processing the laminate,
The area ratio of the glass cloth on the processed surface of the laminate formed in the process of processing the laminate is the glass on the processed surface after the melt-deformed portion of the glass cloth on the processed surface is removed by polishing. Within the range of 120 to 180% with respect to the area ratio of the cloth,
A method for manufacturing a laser-processed product. preparing a laminate in which a first metal layer, a substrate and a second metal layer are laminated in this order;
and processing the laminate by irradiating the laminate with a laser beam,
The base material has a thickness of 200 μm or more, in which a glass cloth having a linear expansion coefficient of 8×10 ⁻⁶ /° C. or less and a thickness of 30 to 95 μm and a resin layer having a thickness of 5 to 50 μm are alternately laminated. is a resin composite material,
The laser beam is a pulse laser beam having an output of 10 to 200 W and a repetition frequency of 1000 to 5000 kHz, and is scanned at a speed of 1000 to 5000 mm / s in the step of processing the laminate,
The area ratio of the glass cloth on the processed surface of the laminate formed in the process of processing the laminate is the glass on the processed surface after the melt-deformed portion of the glass cloth on the processed surface is removed by polishing. Within the range of 120 to 180% with respect to the area ratio of the cloth,
A method for manufacturing a laser-processed product. The base material has three or more layers of the glass cloth,
The thickness of the base material is 500 μm or less,
The method for producing a laser-processed product according to claim 1 or 2 . The method for manufacturing a laser-processed product according to any one of claims 1 to 3 , wherein in the step of processing the laminate, a plurality of elongated holes whose long axes are parallel to each other are formed in the laminate. 5. The method of manufacturing a laser-processed product according to claim 4 , further comprising the step of plating the inner surface of said elongated hole. The method for producing a laser-processed product according to any one of claims 1 to 5 , wherein a width processed by the laser beam in the step of processing the laminate is 10 to 30 µm. The method for producing a laser-processed product according to any one of claims 1 to 6 , wherein the first metal layer is a copper alloy or copper layer having a thickness of 1 to 15 µm. The method for manufacturing a laser-processed product according to any one of claims 1 to 7 , wherein the second metal layer is a copper alloy or copper layer having a thickness of 1 to 15 µm.

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