JPWO2018194066A1 - Method for manufacturing carrier film and electronic component - Google Patents

Abstract

When a hole formed as at least one of a through hole and a bottomed hole is formed in a sheet member formed on a carrier film by an ultraviolet laser, excessive processing near an interface between the two is suppressed, and a carrier film using the same. The present invention provides a method of manufacturing an electronic component. The carrier film (10) is used for molding the sheet member (20), and has a center wavelength of 355 nm to 365 nm, and is irradiated with an ultraviolet laser (B) having a wavelength distribution including a wavelength of 375 nm or more. In the wavelength distribution of the laser (B), the absorptance of a component less than 375 nm is 50% or more, and the absorptivity of a component of 375 nm or more is less than 50%.

Description

  The present invention relates to a carrier film used for forming a sheet member, and a method for manufacturing an electronic component including a step of forming at least one of a through hole and a bottomed hole in a sheet member formed thereon. It is.

  The sheet member is used as a component of an electronic component or a component of an intermediate product in a process of manufacturing the electronic component. An example of the sheet member is a ceramic green sheet. As an example of a method of manufacturing a ceramic electronic component including a step of forming a through hole in a ceramic green sheet, there is a method of manufacturing a ceramic electronic component described in Japanese Patent Application Laid-Open No. 6-304774 (Patent Document 1).

  In the method for manufacturing a ceramic electronic component described in Patent Document 1, a laser is applied to a carrier film made of, for example, polyethylene terephthalate (hereinafter abbreviated as PET) and a ceramic green sheet molded thereon. At that time, the laser is irradiated from the carrier film side. As a result, through holes are formed in both the carrier film and the ceramic green sheet formed thereon.

  The above-mentioned through-hole is filled with a conductive paste containing a metal powder. The ceramic green sheet in which the conductive paste is filled in the through holes is fired after the carrier film is peeled off. The conductive paste filled in the through holes becomes via conductors after firing.

JP-A-6-304774

  In recent years, with the miniaturization of electronic components, the diameter of via conductors has been reduced. As a laser used in a process of forming a through hole for a small-diameter via conductor in a sheet member, use of an ultraviolet laser suitable for processing a minute region is being studied. As an example of the ultraviolet laser, for example, a laser having a center wavelength of 355 nm and a wavelength distribution including a wavelength of 375 nm or more can be given.

  However, when a material having a low ultraviolet laser absorptivity in most of the wavelength distribution is used as the material of the carrier film, it may be difficult to form a through hole in the carrier film. On the other hand, when a material having a high ultraviolet laser absorptivity in most of the wavelength distribution is used as the material of the carrier film, the formation of the through-holes in the carrier film is facilitated. However, in that case, there is a possibility that the hole diameter near the interface between the carrier film and the sheet member becomes large.

  FIG. 2 is a drawing for explaining in more detail the problem when a material having a high absorptivity of an ultraviolet laser in most of the wavelength distribution is used as the material of the carrier film. FIGS. 2A to 2E schematically show main parts of each step sequentially performed in an example of a method of manufacturing an electronic component including a step of forming a through hole in a sheet member using an ultraviolet laser. It is sectional drawing.

FIG. 2A is a cross-sectional view illustrating a step in which the carrier film 110 is manufactured or prepared. For the carrier film 110, a material having a high absorptivity of the ultraviolet laser in most of the above-described wavelength distribution, such as polyethylene naphthalate (hereinafter abbreviated as PEN), is used. FIG. 2B is a cross-sectional view illustrating a step of forming the sheet member 120 on one main surface of the carrier film 110. The material and the forming method of the sheet member 120 are not particularly limited.

  FIG. 2C is a cross-sectional view showing a step of forming a through-hole 130 in the carrier film 110 and the sheet member 120 formed on one main surface thereof by irradiation with the ultraviolet laser B. The ultraviolet laser B is applied from the other main surface side of the carrier film 110. As a result, through holes 130 are formed in the carrier film 110 and the sheet member 120.

  The component near the center wavelength in the ultraviolet laser B is easily absorbed from the other main surface side of the carrier film 110. Therefore, the carrier film 110 is perforated from the other main surface side by a component near the center wavelength in the ultraviolet laser B. On the other hand, the above-mentioned component having a wavelength of 375 nm or more is easily absorbed from one main surface side of the carrier film 110. Therefore, the carrier film 110 is also perforated from one main surface side by the above components.

  At this time, since the sheet member 120 is provided on one main surface of the carrier film 110, heat generated at the time of perforation is easily trapped at the interface between the two. Therefore, the processing by the component having a wavelength of 375 nm or more in the ultraviolet laser B excessively proceeds, and as shown in FIG. 2C, a portion 130a having a large hole diameter is formed near the interface between the two.

  FIG. 2D is a cross-sectional view showing a step of filling a conductive hole 140 formed in the carrier film 110 and the sheet member 120 with the conductive paste 140. The conductive paste 140 is also filled in a portion 130a having an increased hole diameter near the interface between the carrier film 110 and the sheet member 120.

  FIG. 2E is a cross-sectional view showing a step of peeling carrier film 110 from sheet member 120. As a result of the conductive paste 140 being filled also in the portion 130a having the larger hole diameter, a portion 140a of the conductive paste 140 protruding from an unintended through hole is formed on the sheet member 120 after the carrier film 110 is peeled off. appear. Although not shown in FIG. 2E, when a plurality of via conductors are provided, there is a possibility that adjacent via conductors may come into contact with each other.

  The above problem can occur not only when a ceramic green sheet is formed as a sheet member on a carrier film, but also when a resin sheet is formed. Further, the above problem may occur not only when a through hole is formed in the sheet member but also when a bottomed hole is formed.

  An object of the present invention is to suppress excessive processing in the vicinity of an interface between a through-hole and a bottomed hole when an ultraviolet laser is used to form a hole in a sheet member formed on a carrier film. The purpose is to provide a carrier film. Another object of the present invention is to provide a method for manufacturing an electronic component using the above carrier film.

  In the carrier film according to the present invention, the absorption of the irradiated ultraviolet laser is improved.

The present invention is first directed to a carrier film.
The carrier film according to the present invention is used for forming a sheet member. Then, when an ultraviolet laser having a wavelength distribution having a center wavelength of 355 nm to 365 nm and including a wavelength of 375 nm or more is irradiated, the absorptance of a component of less than 375 nm in the wavelength distribution of the ultraviolet laser is 50% or more. Further, the absorptance of a component having a wavelength of 375 nm or more in the wavelength distribution of the ultraviolet laser is less than 50%.

  In the above carrier film, a sheet member is formed on one main surface, and when the ultraviolet laser is irradiated from the other main surface side, absorption of a component having a wavelength of 375 nm or more from the one main surface side is suppressed. Therefore, when a through hole is formed in the carrier film and at least one of the through hole and the bottomed hole is formed in the sheet member by the ultraviolet laser, excessive processing near the interface between the both is suppressed.

  The carrier film according to the present invention preferably has the following features. That is, the carrier film according to the present invention contains polyethylene terephthalate (PET) and polyethylene naphthalate (PEN). The ratio of the weight of PEN to the sum of the weight of PET and the weight of PEN is 0.05 or more and 0.25 or less.

  In the above carrier film, a sheet member is formed on one main surface, and when the above-described ultraviolet laser is irradiated from the other main surface side, it is easy to suppress absorption of a component having a wavelength of 375 nm or more from the one main surface side. Is realized.

The present invention is also directed to a method for manufacturing an electronic component.
The method for manufacturing an electronic component according to the present invention includes a step of forming at least one of a through hole and a bottomed hole in a sheet member formed on a carrier film. The electronic component manufacturing method according to the present invention includes the following first to fifth steps.

  The first step is a step of preparing or preparing a carrier film. The second step is a step in which a sheet member is formed on one main surface of the carrier film. In the third step, a through hole is formed in the carrier film by irradiating the carrier film and the sheet member formed on the carrier film with an ultraviolet laser from the other main surface side of the carrier film, and the through hole is formed in the sheet member. In this step, at least one of the hole and the bottomed hole is formed. The ultraviolet laser has a center wavelength of 355 nm to 365 nm, and has a wavelength distribution including a wavelength of 375 nm or more.

  The fourth step is a step in which the conductive paste is filled into the through holes formed in the carrier film and the holes formed in the sheet member. The fifth step is a step in which the carrier film is peeled from the sheet member in which the conductive paste is filled in the holes. The above-mentioned carrier film is the above-described carrier film according to the present invention.

  In the above method for manufacturing an electronic component, the carrier film according to the present invention is used. Therefore, when a through-hole is formed in the carrier film by the ultraviolet laser and the above-described hole is formed in the sheet member, excessive processing near the interface between the two is suppressed. Therefore, the conductive paste is prevented from protruding from the holes on the sheet member after the carrier film is peeled off. As a result, contact between adjacent via conductors is suppressed.

  In the carrier film according to the present invention, the through-hole is formed in the carrier film by the ultraviolet laser, and when the above-described hole is formed in the sheet member, excessive processing near the interface between the two is suppressed. Further, in the method for manufacturing an electronic component according to the present invention, the conductive paste is prevented from protruding from the holes on the sheet member after the carrier film is peeled off. As a result, contact between adjacent via conductors is suppressed.

It is a drawing explaining an example of a manufacturing method of an electronic component using a carrier film according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a drawing for explaining a problem to be solved by the present invention, illustrating an example of a method for manufacturing an electronic component using a carrier film made of a material having a high absorptivity of an ultraviolet laser in most of a wavelength distribution.

  Hereinafter, embodiments of the present invention will be described, and features of the present invention will be described in more detail. INDUSTRIAL APPLICABILITY The present invention is widely applied to both the manufacture of ceramic electronic components manufactured by molding ceramic green sheets, such as ceramic multilayer substrates and ceramic fuel cells, and the manufacture of non-ceramic electronic components such as resin multilayer substrates. .

-Embodiment of carrier film-
For the majority of the wavelength distribution in a given ultraviolet laser, when the ultraviolet laser is applied to a carrier film made of a material having a high absorptance, the carrier film is perforated from both the irradiation surface and its opposite surface. Go. That is, as described above, an excessively processed portion occurs on the facing surface side. In order to solve such a problem, the inventor has conducted intensive studies, and as a result, found a condition for suppressing absorption of the ultraviolet laser on the facing surface, and has accomplished the present invention.

  The carrier film according to the present invention has the following features. That is, when an ultraviolet laser having a central wavelength of 355 nm to 365 nm and a wavelength distribution including a wavelength of 375 nm or more is irradiated, the absorptance of a component of less than 375 nm in the wavelength distribution of the ultraviolet laser is 50% or more. Further, the absorptance of a component having a wavelength of 375 nm or more in the wavelength distribution of the ultraviolet laser is less than 50%.

  The above conditions are realized when the carrier film contains PET and PEN, and the ratio of the weight of PEN to the sum of the weight of PET and the weight of PEN is 0.05 or more and 0.25 or less. You. Further, the above condition is also realized by making the carrier film contain PET and an ultraviolet absorber. However, the specific configuration of the carrier film for realizing the above conditions is not limited to these.

  UV absorbers include phenyl salicylate, p-tert-butylphenyl salicylate, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, -(2'-hydroxy-5'-tert-methylphenyl) benzotriazole, 2- (2H-benzotriazol-2-yl) -4-6-bis (1-methyl-1-phenylethyl) phenol, 2- It is at least one organic compound selected from ethylhexyl-2-cyano-3,3'-diphenylacrylate and ethyl-2-cyano-3,3'-diphenylacrylate.

  The present invention will be described more specifically based on experimental examples. The carrier film is manufactured to have a thickness of 25 μm. On one main surface of the carrier film, a sheet member is formed so as to have a thickness of 10 μm. Here, the sheet member is a ceramic green sheet containing a low-temperature fired ceramic material. The ultraviolet laser applied to the carrier film has a center wavelength of 355 nm to 365 nm, and has a wavelength distribution including a wavelength of 375 nm or more. The ultraviolet laser is irradiated from the other main surface side of the carrier film. In this experimental example, through holes are formed in both the carrier film and the sheet member by the irradiation of the ultraviolet laser.

  According to this experimental example, the absorptance of a component having a wavelength of less than 375 nm and the absorptivity of a component having a wavelength of 375 nm or more when the above-described ultraviolet laser is applied to the carrier film are defined. The carrier film used in the experimental example can be manufactured by a known method such as a biaxial stretching method.

  Table 1 shows the absorptivity of the ultraviolet laser and the value of the opening diameter at various positions of the formed through-hole when the above-mentioned ultraviolet laser was irradiated on various carrier films of this experimental example. Have been. The absorptance of the ultraviolet laser is divided into a component having a wavelength λ of 300 nm or more and less than 355 nm, a component having a wavelength λ of 355 nm or more and less than 375 nm, and a component having a wavelength λ of 375 nm or more and less than 425 nm. The absorptance of each wavelength component of the ultraviolet laser is measured by a spectrophotometer. In addition, "film" of Table 1 represents a carrier film, and "sheet" represents a sheet member.

  When the absorptance was low for most of the wavelength distribution as in Sample 1, it was difficult to form a through-hole within a predetermined time. In addition, as in Sample 2, among components having a wavelength λ of less than 375 nm, there are components having an absorptivity of less than 50%, and when the component having a wavelength λ of 375 nm or more has an absorptance of 50% or more, it is formed. The shape of the through hole became irregular. This is because the processing from the one main surface side of the carrier film and the sheet member side proceeded, and the gas generated by the thermal decomposition of the carrier film and the sheet member prevented the processing from the other main surface side of the carrier film. Can be

  Further, when the absorptance is high for most of the wavelength distribution as in samples 6 to 8, the vicinity of the interface between the carrier film and the sheet member is excessively processed. As a result, the value of the aperture diameter on the ultraviolet laser emitting side of the carrier film and the value of the opening diameter of the ultraviolet laser incident side on the sheet member are both 100 μm or more.

  On the other hand, as in Samples 3 to 5, when the absorption of a component having a wavelength λ of less than 375 nm is 50% or more and the absorption of a component having a wavelength λ of 375 nm or more is less than 50%, various types of through-holes are formed. The value of the opening diameter at each position was less than 100 μm. Here, in Sample 3, the weight ratio of PEN to the sum of the weights of PEN and PET is 0.05, in Sample 4, the weight ratio of PEN to the sum of the weights of PEN and PET is 0.14, and in Sample 5, PEN is And the weight ratio of PEN to the sum of the weights of PET and PET is 0.25. Therefore, when the weight ratio of PEN to the sum of the weight of PET and the weight of PEN in the carrier film is 0.05 or more and 0.25 or less, good processing results can be obtained.

-Manufacturing method of electronic parts-
FIG. 1 is a diagram illustrating an example of a method for manufacturing an electronic component using the carrier film according to the present invention. FIGS. 1A to 1E show an example of an electronic component manufacturing method including a step of forming at least one of a through hole and a bottomed hole in a sheet member formed on a carrier film. It is sectional drawing which represents the principal part of each process performed sequentially, respectively.

  In this example, the case where through holes are formed in both the carrier film and the sheet member by irradiation of the ultraviolet laser is shown, but the through holes are formed in the carrier film, and the bottomed holes are formed in the sheet member. May be performed.

  Each drawing is a schematic diagram, and does not necessarily reflect the actual dimensions of the product. Further, variations in the shape of each component that occur in the manufacturing process are not necessarily reflected in each drawing. In other words, hereinafter, the drawings used for description in this specification can be said to represent an actual product in an essential aspect even if there are portions different from the actual product.

  FIG. 1A is a cross-sectional view illustrating a step (first step) of manufacturing or preparing the carrier film 10. The carrier film 10 is a carrier film according to the present invention, and contains PEN and PET in the above-described weight ratio. That is, the ratio of the weight of PEN to the sum of the weight of PET and the weight of PEN is 0.05 or more and 0.25 or less. The carrier film 10 has a thickness of, for example, 25 μm to 100 μm in consideration of the time required for forming the through hole and the handling of the sheet member 20 formed thereon in the second step described later. It is produced as follows.

  On one main surface side (the side on which the sheet member 20 is formed in the second step described later) of the carrier film 10, a release layer for improving the releasability of the sheet member 20 in the fifth step described later is provided. It may be provided. The release layer is formed using a silicone resin or a fluorine resin.

  In addition, the carrier film 10 may be added with an inorganic material powder for the purpose of adjusting the coefficient of thermal expansion, improving the mechanical strength, preventing the unwinding, and the like. The material of the inorganic material powder is at least one selected from oxides such as aluminum oxide, nitrides such as silicon nitride, and carbides such as silicon carbide. The shape of the inorganic material powder is spherical or flake. From the viewpoint of filling properties, spherical shapes are preferred.

  FIG. 1B is a cross-sectional view illustrating a step (second step) of forming the sheet member 20 on one main surface of the carrier film 10. Here, the sheet member 20 is a ceramic green sheet containing a low-temperature fired ceramic material. For example, a slurry obtained by mixing a powder of a ceramic material, a binder, a plasticizer, and an organic solvent is applied onto one main surface of the carrier film 10 using a lip coater or the like, thereby forming the sheet member 20. The sheet member 20 is formed so as to have a thickness of, for example, between 5 μm and 100 μm.

  FIG. 1C is a cross-sectional view showing a step (third step) of forming a through hole 30 in the carrier film 10 and the sheet member 20 formed on one main surface thereof by irradiation with the ultraviolet laser B. is there. The ultraviolet laser B is applied from the other main surface side of the carrier film 10. The ultraviolet laser B has a center wavelength of 355 nm to 365 nm, and has a wavelength distribution including a wavelength of 375 nm or more. As a result, through holes 30 are formed in both the carrier film 10 and the sheet member 20. The hole diameter of the through hole 30 is set, for example, between 20 μm and 200 μm.

  The carrier film 10 is the carrier film according to the present invention as described above. That is, when the ultraviolet laser B is irradiated from the other main surface side to the carrier film 10 on which the sheet member 20 is formed on the one main surface, absorption of a component having a wavelength of 375 nm or more from the one main surface side is suppressed. . Therefore, when the through hole 30 is formed by the ultraviolet laser in the carrier film 10 and the sheet member 20 formed thereon, excessive processing near the interface between the two is suppressed.

  FIG. 1D is a cross-sectional view showing a step (fourth step) of filling conductive paste 40 into through-holes 30 formed in carrier film 10 and sheet member 20. The material and filling method of the conductive paste 40 are not particularly limited. For example, a conductive paste 40 obtained by mixing a metal powder such as copper, a binder, a plasticizer, and an organic solvent is filled in the through-holes 30 using a screen printing machine or the like.

  In addition, the conductive paste 40 may be added with an inorganic material powder for the purpose of adjusting the shrinkage during sintering and the like. As a material of the inorganic material powder, a ceramic material powder contained in the sheet member 20 is preferable.

  FIG. 1E is a cross-sectional view showing a step (fifth step) of separating the carrier film from the sheet member 20 in which the conductive paste 40 is filled in the through holes. As shown in FIG. 1E, in the method for manufacturing an electronic component according to the present invention, the conductive paste 40 is prevented from protruding from the through-hole 30 on the sheet member 20 after the carrier film 10 is peeled off. Have been. As a result, contact between adjacent via conductors (not shown) is suppressed.

  Although the above-described example of the method for manufacturing an electronic component has been described for the case where the sheet member is a ceramic green sheet, the same steps are performed even when the sheet member is a resin sheet, and the same effect is obtained. Can be Further, in this example, the case where the through hole is formed in the sheet member has been described, but the case where the bottomed hole is formed by changing at least one of the irradiation time and the energy of the ultraviolet laser. Has the same effect.

  It should be noted that the embodiments described in this specification are merely examples, and the present invention is not limited to the above embodiments, and various applications and modifications may be made within the scope of the present invention. Can be.

Reference Signs List 10 carrier film 20 sheet member 30 through hole 40 conductive paste

Claims (3)

A carrier film used for forming a sheet member,
When an ultraviolet laser having a wavelength distribution having a center wavelength of 355 nm to 365 nm and including a wavelength of 375 nm or more is irradiated,
A carrier film, wherein the absorption of a component having a wavelength of less than 375 nm in the wavelength distribution of the ultraviolet laser is 50% or more, and the absorption of a component of 375 nm or more in the wavelength distribution of the ultraviolet laser is less than 50%. Including polyethylene terephthalate and polyethylene naphthalate,
The carrier film according to claim 1, wherein a ratio of the weight of polyethylene naphthalate to the sum of the weight of polyethylene terephthalate and the weight of polyethylene naphthalate is 0.05 or more and 0.25 or less. A method for manufacturing an electronic component, comprising a step of forming a hole that is at least one of a through hole and a bottomed hole in a sheet member formed on a carrier film,
A first step in which the carrier film is prepared or prepared;
A second step of forming the sheet member on one main surface of the carrier film;
The carrier film and the sheet member molded on the carrier film, the center wavelength is 355 nm to 365 nm, an ultraviolet laser having a wavelength distribution including a wavelength of 375 nm or more, from the other main surface side of the carrier film By irradiating, a third step in which a through hole is formed in the carrier film, and a hole that is at least one of a through hole and a bottomed hole is formed in the sheet member;
A fourth step in which a conductive paste is filled in the through-holes formed in the carrier film and the holes formed in the sheet member;
A fifth step of removing the carrier film from the sheet member in which the holes are filled with the conductive paste,
The method for manufacturing an electronic component, wherein the carrier film is the carrier film according to claim 1.