Method for manufacturing electronic component, and electronic component

Abstract

This method for manufacturing an electronic component includes a step for irradiating a substrate 10 containing a thermosetting resin having a benzene ring in a structure thereof with laser light 21 to modify the thermosetting resin, thereby forming a conductive portion 13 containing graphene and / or graphite on a surface 11 of the substrate 10, inside the substrate 10, or both on the surface 11 and inside the substrate 10. The thermosetting resin may contain at least one resin of an epoxy resin and a phenol resin. The wavelength of the laser light 21 may be 200-1100 nm.

Description

Electronic component manufacturing method and electronic component

[0001] This application claims priority to Japanese Patent Application No. 2024-101811, filed June 25, 2024, and incorporates by reference the entire contents of said Japanese application.

[0002] Patent Document 1 discloses a method for manufacturing a polydimethylsiloxane substrate having a silicon carbide structure, which includes a step of irradiating the polydimethylsiloxane substrate with laser light to form a modified portion made of silicon carbide on the polydimethylsiloxane substrate.

[0003] Japanese Patent Application Laid-Open No. 2019-196295

[0004] Conventionally, forming a conductive portion in an electronic component such as a circuit board requires complicated processes such as forming a metal film, forming a mask on the metal film, and etching the metal film through the mask. The present disclosure aims to provide a method for manufacturing an electronic component and an electronic component that can manufacture an electronic component having a conductive portion through a simpler process.

[0005] [1] A method for manufacturing an electronic component according to the present disclosure includes a step of irradiating a substrate containing a thermosetting resin having a benzene ring in its structure with laser light to modify the thermosetting resin, thereby forming a conductive portion containing one or both of graphene and graphite on a surface of the substrate, inside the substrate, or both on the surface and inside of the substrate.

[0006] According to experiments conducted by the present inventors, when a thermosetting resin having a benzene ring in its structure is irradiated with laser light, the conductivity of the conductive portion formed by modifying the thermosetting resin is increased compared to when a thermosetting resin not having a benzene ring in its structure is irradiated with laser light. This is thought to be because highly crystalline graphene and / or graphite produced by modifying the benzene ring contribute to the conductivity. In the manufacturing method [1] above, a substrate containing a thermosetting resin having a benzene ring in its structure is irradiated with laser light to form a conductive portion containing one or both of graphene and graphite. In addition, unlike thermoplastic resins, thermosetting resins do not melt when irradiated with laser light. Therefore, electronic components having conductive portions with excellent conductivity can be manufactured using a process simpler than conventional methods.

[0007] [2] In the manufacturing method of [1] above, the thermosetting resin may contain at least one of an epoxy resin and a phenolic resin. Experiments by the present inventors have shown that, for example, in such a case, a conductive part with excellent conductivity can be obtained.

[0008] [3] In the manufacturing method of [1] or [2] above, the wavelength of the laser light may be 200 nm or more and 1100 nm or less. According to experiments by the present inventors, for example, in such a case, a conductive part with excellent conductivity can be obtained.

[0009] [4] In any of the manufacturing methods [1] to [3] above, the laser light may be pulsed light, and the pulse width of the laser light may be 100 femtoseconds or more and 2 picoseconds or less. According to experiments by the present inventors, for example, in such a case, a conductive portion with excellent conductivity can be obtained.

[0010] [5] In the manufacturing method of [2] above, the wavelength of the laser light is 200 nm or more and 520 nm or less, the pulse width of the laser light is 100 femtoseconds or more and 200 femtoseconds or less, and the fluence of the laser light is 4 J / cm ２ According to experiments by the present inventors, in such a case, the conductivity of the conductive portion can be further increased.

[0011] [6] In the manufacturing method of [2] above, the fluence of the laser light is 0.1 mJ / cm ２ According to experiments by the present inventors, for example, in such a case, a conductive portion with excellent conductivity can be obtained.

[0012] [7] In any of the manufacturing methods [1] to [6] above, the laser beam irradiation pitch may be 0.5 μm or less. According to experiments by the present inventors, for example, in such a case, a conductive part with excellent conductivity can be obtained.

[0013] [8] In any of the manufacturing methods [1] to [7] above, the base material may further contain plant powder dispersed in the thermosetting resin. According to experiments by the inventors, the conductivity of the conductive portion can be further increased by including plant powder in the base material.

[0014] [9] An electronic component according to the present disclosure includes a substrate containing a thermosetting resin having a benzene ring in its structure, and a conductive portion provided on the surface of the substrate, inside the substrate, or both the surface and inside of the substrate, the conductive portion including one or both of graphene and graphite derived from the thermosetting resin. The conductive portion including one or both of graphene and graphite derived from the thermosetting resin provided in the electronic component of [9] can be formed, for example, by irradiating a substrate containing a thermosetting resin having a benzene ring in its structure with laser light. In addition, as described above, when a thermosetting resin having a benzene ring in its structure is irradiated with laser light, the conductivity of the conductive portion formed by modifying the thermosetting resin is increased compared to when a thermosetting resin not having a benzene ring in its structure is irradiated with laser light. Therefore, the electronic component of [9] above can provide an electronic component having a conductive portion with excellent conductivity and that can be manufactured using a simpler process than conventional processes.

[0015]

[10] The electronic component of [9] above may be a circuit board, the base material may be a substrate, and the conductive portion may be a wiring pattern. This circuit board, like the electronic component of [9] above, has a wiring pattern with excellent conductivity, and can be manufactured by a process simpler than conventional processes.

[0016]

[11] In the electronic component of [9] or

[10] , the thermosetting resin may contain at least one of an epoxy resin and a phenolic resin. Experiments by the present inventors have shown that, for example, in such a case, a conductive portion with excellent conductivity can be obtained.

[0017]

[12] In the electronic component of any one of [9] to

[11] above, the substrate may further contain vegetable powder dispersed in the thermosetting resin. According to experiments by the inventors, the inclusion of vegetable powder in the substrate can further increase the conductivity of the conductive portion.

[0018] According to the present disclosure, it is possible to provide a method for manufacturing an electronic component, which allows an electronic component having a conductive portion to be manufactured through a simpler process, and the electronic component.

[0019] FIG. 1 is a perspective view showing an electronic component according to an embodiment of the present disclosure. FIG. 2 is a diagram showing the structural formula of an epoxy resin. FIG. 3 is a diagram showing the structural formulas of a phenolic resin and a urea resin. FIG. 4 is a diagram showing several examples of electrical functional parts. FIG. 5 is a diagram showing an example of a circuit including a capacitor and a spiral inductor formed by a conductive portion. FIG. 6 is a diagram showing an example of a circuit including a capacitor and a spiral inductor formed by a conductive portion. FIG. 7 is a diagram showing an example of a circuit including a capacitor and a spiral inductor formed by a conductive portion. FIG. 8 is a diagram showing the irradiation pitch (μm) and fluence (J / cm) of the laser light when a conductive portion is formed by irradiating a substrate made of paper phenolic resin with laser light. ２ 9 is a graph showing the relationship between the irradiation pitch (μm) and fluence (J / cm) of the laser beam when a conductive portion is formed by irradiating a substrate made of paper phenolic resin with laser light. ２ 10 is a graph showing the relationship between the irradiation pitch (μm) and fluence (J / cm) of the laser beam when a conductive portion is formed by irradiating a substrate made of paper phenolic resin with laser light. ２11 is a graph showing the relationship between the irradiation pitch (μm) and fluence (J / cm) of the laser beam when a conductive portion is formed by irradiating a substrate made of glass epoxy resin with laser beam. ２ 12 is a graph showing the relationship between the irradiation pitch (μm) and fluence (J / cm) of the laser beam when a conductive portion is formed by irradiating a substrate made of glass epoxy resin with laser beam. ２ 13 is a graph showing the relationship between the irradiation pitch (μm) and fluence (J / cm) of the laser beam when a conductive portion is formed by irradiating a substrate made of glass epoxy resin with laser beam. ２ 14 is a graph showing the relationship between the fluence (J / cm) of the laser beam and the conductivity (S / m) of the conductive portion. ２ 15 is a graph showing the results of Raman analysis of a processed portion modified by irradiation with laser light. FIG. 16 is a graph showing the results of Raman analysis of a processed portion modified by irradiation with laser light. FIG. 17 is a graph showing the relationship between the G / D ratio and the resistance value (Ω). FIG. 18 is a graph showing the relationship between the fluence (J / cm) of the laser light and the resistance value (Ω). ２ 19 is a graph showing the results of Raman analysis of a processed portion modified by laser light irradiation. FIG. 20 is a graph showing the relationship between the G / D ratio and the resistance value (Ω). FIG. 21 is a graph showing the relationship between the irradiation pitch (μm) and the fluence (J / cm) of the laser light when a conductive portion is formed by irradiating a substrate made of paper phenolic resin containing 50 mass percent wood flour with laser light. ２ 22 is a table showing the irradiation conditions of the laser light in this example. FIG. 23 is a table showing the calculated and measured values ​​of inductance for four spiral inductors. FIG. 24 is a plan view showing the shape of a capacitor fabricated in this example. FIG. 25 is a table showing the calculated and measured values ​​of capacitance for two capacitors.

[0020] Hereinafter, embodiments of the method for manufacturing an electronic component and the electronic component according to the present disclosure will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are given the same reference numerals, and duplicated explanations will be omitted.

[0021] FIG. 1 is a perspective view showing an electronic component 8 according to an embodiment of the present disclosure. The electronic component 8 includes a substrate 10 and a conductive portion 13. The substrate 10 in this embodiment is a substrate and has a flat surface 11. However, the surface 11 does not have to be flat. The substrate 10 includes a thermosetting resin having a benzene ring in its structure. For example, the thermosetting resin having a benzene ring in its structure includes at least one of an epoxy resin and a phenolic resin. FIG. 2 is a diagram showing the structural formula of an epoxy resin. Part (a) of FIG. 3 is a diagram showing the structural formula of a phenolic resin. As shown in these figures, the epoxy resin and the phenolic resin include a benzene ring 15 in their structures. Part (b) of FIG. 3 is a diagram showing the structural formula of a urea resin as a comparative example. As shown in the same figure, the urea resin does not include a benzene ring in its structure. In one example, the substrate 10 is made of a glass-epoxy resin in which glass fibers are impregnated with an epoxy resin, or a paper-phenolic resin in which a paper substrate is impregnated with a phenolic resin. The substrate 10 may further include plant powder dispersed in the thermosetting resin, or may not include plant powder. The plant powder may be, for example, at least one of wood powder and bamboo powder. The plant powder is not limited to these examples.

[0022] The conductive portion 13 is provided on the surface 11 of the substrate 10, inside the substrate 10, or both the surface 11 and inside the substrate 10. The conductive portion 13 is a portion formed by modifying the thermosetting resin of the substrate 10, and contains one or both of graphene and graphite derived from the thermosetting resin. The conductivity of the conductive portion 13 is, for example, 0.01 S / m or more, 10 S / m or more, or 100 S / m or more. In other words, the resistivity of the conductive portion 13 is, for example, 100 Ω·m or less, 0.1 Ω·m or less, or 0.01 Ω·m or less. The conductivity of the conductive portion 13 is, for example, 100,000 S / m or less.

[0023] The conductive portion 13 includes an electrical functional portion. FIG. 4 is a diagram showing several examples of the electrical functional portion. Part (a) of FIG. 4 shows a spiral inductor formed by a spiral conductive wire. Part (b) of FIG. 4 shows a capacitor formed by a pair of comb-shaped conductive wires facing each other. Part (c) of FIG. 4 shows a resistor formed by a locally narrowed width of a conductive wire. The electrical functional portion is not limited to these examples. The conductive portion 13 may include a single functional portion or multiple functional portions. Of the multiple functional portions, at least two functional portions may be of different types.

[0024] Furthermore, a resonant circuit can be obtained by connecting a capacitor and a spiral inductor in series or parallel. Figures 5 to 7 are diagrams showing examples of circuits including a capacitor and a spiral inductor formed by conductive portions 13. Part (a) of Figure 5 shows a low-pass filter configured with conductive portions 13. This low-pass filter includes a capacitor 31 formed by a pair of opposing comb-shaped conductive portions 13, and a spiral inductor 32 formed by a spiral-shaped conductive portion 13. One comb-shaped conductive portion 13 of the capacitor 31 is connected to an input terminal 33 and one end of the spiral inductor 32. The other comb-shaped conductive portion 13 of the capacitor 31 is connected to a reference potential line 35. The other end of the spiral inductor 32 is connected to an output terminal 34.

[0025] 5(b) shows a high-pass filter configured by the conductive portion 13. This high-pass filter includes a capacitor 31 and a spiral inductor 32. One comb-tooth-shaped conductive portion 13 of the capacitor 31 is connected to an input terminal 33. The other comb-tooth-shaped conductive portion 13 of the capacitor 31 is connected to one end of the spiral inductor 32 and is also connected to an output terminal 34. The other end of the spiral inductor 32 is connected to a reference potential line 35.

[0026] 6A shows a bandpass filter configured by conductive portions 13. This bandpass filter includes a capacitor 31 and a spiral inductor 32. One comb-shaped conductive portion 13 of the capacitor 31 is connected to an input terminal 33. The other comb-shaped conductive portion 13 of the capacitor 31 is connected to one end of the spiral inductor 32. The other end of the spiral inductor 32 is connected to an output terminal 34.

[0027] 6(b) shows a band elimination filter configured with conductive portions 13. This band elimination filter includes a capacitor 31 and a spiral inductor 32. One comb-tooth-shaped conductive portion 13 of the capacitor 31 is connected to an input terminal 33 and an output terminal 34. The other comb-tooth-shaped conductive portion 13 of the capacitor 31 is connected to one end of the spiral inductor 32. The other end of the spiral inductor 32 is connected to a reference potential line 35.

[0028] 7 shows an antenna circuit configured by a conductive portion 13. This antenna circuit includes a capacitor 31, a spiral inductor 32, and an antenna 36. One comb-tooth-shaped conductive portion 13 of the capacitor 31 is connected to a reference potential line 35. The other comb-tooth-shaped conductive portion 13 of the capacitor 31 is connected to one end of the antenna 36, ​​one end of the spiral inductor 32, and an output terminal 34. The other end of the spiral inductor 32 is connected to the reference potential line 35. The antenna 36 has an arbitrary length, for example, ¼ of the wavelength of the received signal.

[0029] Generally, capacitors have the property of blocking low-frequency signals and allowing high-frequency signals to pass easily. Conversely, inductors have the property of blocking high-frequency signals and allowing low-frequency signals to pass easily. Therefore, for example, in the low-pass filter shown in FIG. 5A, by connecting a spiral inductor 32 in series with the input terminal 33, low-frequency signals are selectively output. Furthermore, by connecting a capacitor 31 between the input terminal 33 and the reference potential line 35, high-frequency signals flow to the reference potential line 35 and are not output. This allows the filter to function as a low-pass filter. Furthermore, by connecting multiple low-pass filters in multiple stages, it is possible to achieve a steeper cutoff characteristic. Similarly, in other filters (high-pass filters, band-pass filters, band elimination filters), the frequency characteristics of the capacitor 31 and spiral inductor 32 can be used to select the frequency of signals passing from the input terminal 33 to the output terminal 34.

[0030] Alternatively, the electronic component 8 may be a wiring board. When the electronic component 8 is a wiring board, the conductive portion 13 includes a wiring pattern. The conductive portion 13 of the wiring board may further include an electrical functional portion in addition to the wiring pattern.

[0031] A method for manufacturing the electronic component 8 will be described. The method for manufacturing the electronic component 8 includes a step of forming a conductive portion 13. As shown in FIG. 1 , the conductive portion 13, which includes one or both of graphene and graphite, is formed by irradiating the surface 11 of the substrate 10, the interior of the substrate 10, or both the surface 11 and the interior of the substrate 10 with laser light 21 to modify a thermosetting resin. The laser light 21 is scanned along the extension direction of the conductive portion 13. The wavelength of the laser light 21 is, for example, 200 nm or more, or 300 nm or more. The wavelength of the laser light 21 is, for example, 1100 nm or less, or 520 nm or less. The laser light 21 is, for example, pulsed light. The pulsed light may be a single pulse, or may be a multi-pulse in which a single pulse is divided into multiple pulses. The pulse width of the laser light 21 is, for example, 100 femtoseconds or more. The pulse width of the laser light 21 is, for example, 2 picoseconds or less, or 200 femtoseconds or less. The fluence of the laser light 21 is, for example, 0.1 mJ / cm ２ or more than 4 J / cm ２ or more, and 1000 J / cm ２ The following is the result.

[0032] The effects obtained by the electronic component 8 and the manufacturing method thereof according to the present embodiment described above will now be described. Conventionally, forming a conductive portion in an electronic component such as a circuit board requires complex processes such as forming a metal film, forming a mask on the metal film, and etching the metal film through the mask.

[0033] According to experiments described below, when a thermosetting resin having a benzene ring 15 in its structure is irradiated with laser light 21, the conductivity of the conductive portion 13 formed by modifying the thermosetting resin is increased compared to when a thermosetting resin not having a benzene ring 15 in its structure is irradiated with laser light 21. This is thought to be because the highly crystalline graphene and / or graphite produced by modifying the benzene ring 15 contributes to the conductivity. In this embodiment, a substrate 10 including a thermosetting resin having a benzene ring 15 in its structure is irradiated with laser light 21 to form a conductive portion 13 including one or both of graphene and graphite. In addition, unlike thermoplastic resins, thermosetting resins do not melt when irradiated with laser light 21. Therefore, an electronic component 8 including a conductive portion 13 with excellent conductivity can be manufactured using a process simpler than conventional processes.

[0034] As described above, the thermosetting resin may contain at least one of an epoxy resin and a phenol resin. According to experiments described later, in such a case, for example, a conductive portion 13 having excellent conductivity can be obtained.

[0035] As described above, the wavelength of the laser light 21 may be 200 nm or more and 1100 nm or less. According to the experiment described later, in such a case, for example, a conductive portion 13 with excellent conductivity can be obtained.

[0036] As described above, the laser light 21 is pulsed light, and the pulse width of the laser light 21 may be 100 femtoseconds or more and 2 picoseconds or less. According to the experiment described later, in such a case, for example, a conductive portion 13 with excellent conductivity can be obtained.

[0037] As described above, the wavelength of the laser light 21 is 200 nm or more and 520 nm or less, the pulse width of the laser light 21 is 100 femtoseconds or more and 200 femtoseconds or less, and the fluence of the laser light 21 is 4 J / cm ２ According to an experiment to be described later, in such a case, the conductivity of the conductive portion 13 can be further increased.

[0038] As mentioned above, the fluence of the laser light 21 is 0.1 mJ / cm ２According to an experiment described later, in such a case, for example, a conductive portion 13 with excellent conductivity can be obtained.

[0039] The irradiation pitch of the laser beam 21 may be greater than 0 μm and equal to or less than 0.5 μm. According to experiments described later, in such a case, for example, a conductive portion 13 with excellent conductivity can be obtained. The irradiation pitch (μm) of the laser beam 21 is the distance (interval) between irradiation positions when the laser beam 21 is irradiated onto the substrate 10 with shifted positions. In other words, the irradiation pitch (μm) of the laser beam 21 is the distance between the center of a processing spot formed by a light pulse and the center of a processing spot formed by the next light pulse irradiated.

[0040] As described above, the substrate 10 may further include plant powder dispersed in the thermosetting resin. According to experiments described below, when the substrate 10 includes plant powder, the plant powder is irradiated with the laser light 21 and converted into graphene or graphite, thereby further increasing the conductivity of the conductive portion 13.

[0041] The electronic component 8 of this embodiment includes a substrate 10 containing a thermosetting resin having a benzene ring 15 in its structure, and a conductive portion 13 provided on the surface 11 of the substrate 10, inside the substrate 10, or both the surface 11 and inside the substrate 10, and containing one or both of graphene and graphite derived from the thermosetting resin. The conductive portion 13 of the electronic component 8, containing one or both of graphene and graphite derived from the thermosetting resin, can be formed, for example, by irradiating the substrate 10 containing a thermosetting resin having a benzene ring 15 in its structure with laser light 21. In addition, as described above, when a thermosetting resin having a benzene ring 15 in its structure is irradiated with laser light 21, the conductivity of the conductive portion 13 formed by modifying the thermosetting resin is increased compared to when a thermosetting resin not having a benzene ring 15 in its structure is irradiated with laser light 21. Therefore, this embodiment can provide an electronic component 8 that includes a conductive portion 13 with excellent conductivity and can be manufactured using a simpler process than conventional processes.

[0042] The circuit board of this embodiment includes a substrate containing a thermosetting resin having benzene rings 15 in its structure, and a wiring pattern that is provided on surface 11 of the substrate, inside the substrate, or both on surface 11 and inside the substrate and contains one or both of graphene and graphite derived from the thermosetting resin. This circuit board can provide a wiring pattern that has excellent conductivity, similar to electronic component 8 described above, and can be manufactured by a process that is simpler than conventional processes.

[0043] The details of the experiments conducted by the present inventors are described below. In the following experiments, the repetition frequency of the laser beam 21 was set to 20 kHz. In addition, the spot diameter of the laser beam 21 having a wavelength of 343 nm and a pulse width of 185 fs was set to 35 μm. The spot diameter of the laser beam 21 having a wavelength of 515 nm and a pulse width of 185 fs was set to 30 μm. The spot diameter of the laser beam 21 having a wavelength of 515 nm and a pulse width of 1.0 ps was set to 3.6 μm. The spot diameter of the laser beam 21 having a wavelength of 1030 nm and a pulse width of 1.0 ps was set to 10.3 μm. The processing depth was 100 μm.

[0044] 8 to 10 show the relationship between the irradiation pitch (μm) and the fluence (J / cm) of the laser beam 21 when the conductive portion 13 is formed by irradiating the substrate 10 made of paper phenolic resin with the laser beam 21. ２ ) and the conductivity (S / m) of the conductive portion 13. In these figures, the black dot plot P11 indicates no conduction (conductivity less than 0.01 S / m), the hatched plot P12 indicates a conductivity of 0.01 S / m or more but less than 10 S / m, the white dot plot P13 indicates a conductivity of 10 S / m or more but less than 100 S / m, and the half-toned plot P14 indicates a conductivity of 100 S / m or more. Some plots in the figures show specific conductivity values. In this experiment, processing was performed by gradually shifting the irradiation spot of the laser light 21, in other words, so that the irradiation spots partially overlapped each other.

[0045] Part (a) of Figure 8 shows the results when using laser light 21 with a wavelength of 343 nm and a pulse width of 185 fs. Part (b) of Figure 8 shows the results when using laser light 21 with a wavelength of 515 nm and a pulse width of 185 fs. Comparing part (a) of Figure 8 with part (b) of Figure 8 shows that the threshold fluence of laser light 21 is smaller when the wavelength of laser light 21 is 343 nm than when the wavelength of laser light 21 is 515 nm; in other words, less energy is required for laser light 21. In addition, referring to parts (a) and (b) of Figure 8 shows that the conductivity of conductive portion 13 is greatest when the irradiation pitch of laser light 21 is 0.25 μm, and that the conductivity decreases, i.e., the resistance value increases, when the irradiation pitch is greater or smaller than 0.25 μm.

[0046] Part (a) of Figure 9 shows the results when using laser light 21 having a wavelength of 515 nm and a pulse width of 1.0 ps. Part (b) of Figure 9 shows the results when using laser light 21 having a wavelength of 515 nm and a pulse width of 185 fs. Comparing part (a) of Figure 9 with part (b) of Figure 9 shows that the fluence threshold of laser light 21 is smaller when the pulse width of laser light 21 is 185 fs than when it is 1.0 ps. In addition, part (a) of Figure 9 shows that when the pulse width of laser light 21 is 1.0 ps, ​​the conductivity of conductive portion 13 increases when the irradiation pitch of laser light 21 is 0.10 μm or less.

[0047] Part (a) of Figure 10 shows the results when using laser light 21 with a wavelength of 515 nm and a pulse width of 1.0 ps. Part (b) of Figure 10 shows the results when using laser light 21 with a wavelength of 1030 nm and a pulse width of 1.0 ps. Comparing part (a) of Figure 10 with part (b) of Figure 10, it can be seen that the fluence threshold of laser light 21 is smaller when the wavelength of laser light 21 is 1030 nm than when the wavelength of laser light 21 is 515 nm. In addition, referring to parts (a) and (b) of Figure 10, it can be seen that the conductivity of conductive portion 13 increases as the irradiation pitch of laser light 21 decreases.

[0048] 11 to 13 show the relationship between the irradiation pitch (μm) and the fluence (J / cm) of the laser light 21 when the conductive portion 13 is formed by irradiating the substrate 10 made of glass epoxy resin with the laser light 21. ２ 8 to 10. In these figures, the plots P11 to P14 have the same meanings as in FIGS. 8 to 10.

[0049] Part (a) of Fig. 11 shows the results when using laser light 21 with a wavelength of 343 nm and a pulse width of 185 fs. Part (b) of Fig. 11 shows the results when using laser light 21 with a wavelength of 515 nm and a pulse width of 185 fs. Comparing part (a) of Fig. 11 with part (b) of Fig. 11, it can be seen that the fluence threshold of laser light 21 is smaller when the wavelength of laser light 21 is 343 nm than when the wavelength of laser light 21 is 515 nm.

[0050] Part (a) of Fig. 12 shows the results when using laser light 21 having a wavelength of 515 nm and a pulse width of 1.0 ps. Part (b) of Fig. 12 shows the results when using laser light 21 having a wavelength of 515 nm and a pulse width of 185 fs. Comparing part (a) of Fig. 12 with part (b) of Fig. 12, it can be seen that the fluence threshold of laser light 21 is smaller when the pulse width of laser light 21 is 185 fs than when it is 1.0 ps.

[0051] Part (a) of Figure 13 shows the results when using laser light 21 with a wavelength of 515 nm and a pulse width of 1.0 ps. Part (b) of Figure 13 shows the results when using laser light 21 with a wavelength of 1030 nm and a pulse width of 1.0 ps. Comparing part (a) of Figure 13 with part (b) of Figure 13 shows that the fluence threshold of laser light 21 is smaller when the wavelength of laser light 21 is 1030 nm than when the wavelength of laser light 21 is 515 nm. In addition, referring to parts (a) and (b) of Figure 13 shows that the conductivity of conductive portion 13 increases as the irradiation pitch of laser light 21 decreases.

[0052] From the above results, it can be seen that an example of the wavelength of the laser light 21 is in the range including 343 nm and 515 nm and their surroundings, i.e., 200 nm to 520 nm. In addition, it can be seen that an example of the pulse width of the laser light 21 is in the range including 185 fs and its surroundings, i.e., 100 fs to 200 fs. In this case, when the fluence of the laser light 21 is 4 J / cm ２ If it is equal to or greater than this, the conductivity can be made 0.01 S / m or more.

[0053] Second Example Next, the results of an experiment on the difference in conductivity depending on whether or not the benzene ring 15 is present in the thermosetting resin will be described. ２ 14 is a graph showing the relationship between the resistance (Ω) of the conductive portion 13 and the thickness of the substrate 10. In FIG. 14, the black dot plot P21 indicates the case where the substrate 10 is made of paper phenolic resin, the hatched plot P22 indicates the case where the substrate 10 is made of only phenolic resin and does not contain paper or the like, and the white dot plot P23 indicates the case where the substrate 10 is made of urea resin. Part (a) of FIG. 14 shows the results when using laser light 21 having a wavelength of 1030 nm and a pulse width of 1.0 ps. Part (b) of FIG. 14 shows the results when using laser light 21 having a wavelength of 515 nm and a pulse width of 1.0 ps.

[0054] In this experiment, the conductivity of the phenolic resin was increased by 10 －９ ~10 －１０ From 6.8 x 10 ２ The conductivity of the urea resin changes by 10 －１０ ~10 －１１ From 1.5 x 10 ０ The change was 11 orders of magnitude. Thus, the change in conductivity was greater for phenolic resin than for urea resin. This is thought to be because the benzene rings 15 contribute significantly to the improvement in conductivity due to irradiation with laser light 21. In addition, the conductivity was greater when the substrate 10 was made only of phenolic resin and did not contain paper or the like than when the substrate 10 was made of paper phenolic resin. This is thought to be because the phenolic resin, not paper, contributed significantly to the improvement in conductivity due to irradiation with laser light 21.

[0055] 15 and 16 are graphs showing Raman analysis results of workpiece portions modified by irradiation with laser light 21. Parts (a) to (c) of FIG. 15 and part (a) of FIG. 16 show Raman spectrum waveforms when the substrate 10 is made of paper phenolic resin. Part (a) of FIG. 15 shows the analysis results of workpiece portions with different resistance values ​​when the pulse width of the laser light 21 is 185 fs. Part (b) of FIG. 15 shows the analysis results of workpiece portions with different resistance values ​​when the pulse width of the laser light 21 is 1.0 ps. Part (c) of FIG. 15 shows the analysis results of workpiece portions with different processing conditions, only the wavelength of the laser light 21, when the pulse width of the laser light 21 is 1.0 ps. Part (a) of FIG. 16 shows the analysis results of workpiece portions with different processing conditions, only the number of pulses of the laser light 21, when the pulse width of the laser light 21 is 185 fs. Part (b) of FIG. 16 shows the Raman spectrum waveform when the substrate 10 is made of urea resin and the pulse width of the laser light 21 is set to 1.0 ps.

[0056] As is clear from comparing parts (a) to (c) of Figure 15 and part (a) of Figure 16 with part (b) of Figure 16, the Raman spectrum waveform of the processed part in the paper phenolic resin is significantly different from the Raman spectrum waveform of the processed part in the urea resin. This means that the composition of the product in the processed part in the paper phenolic resin is significantly different from the composition of the product in the processed part in the urea resin.

[0057] FIG. 17 is a graph showing the relationship between the G / D ratio and the resistance value (Ω). The G / D ratio is the ratio of the peak intensity of the G band to the peak intensity of the D band, and is also called the R value. In FIG. 17, plots P31 to P35 show the case where the substrate 10 is made of paper phenolic resin. Plot P31 shows the case where the wavelength of the laser beam 21 is 343 nm and the pulse width is 185 fs. Plot P32 shows the case where the wavelength of the laser beam 21 is 515 nm and the pulse width is 185 fs. Plot P33 shows the case where the wavelength of the laser beam 21 is 515 nm and the pulse width is 1.0 ps. Plot P34 shows the case where the wavelength of the laser beam 21 is 1030 nm and the pulse width is 1.0 ps. Plot P35 shows the case where the wavelength of the laser beam 21 is 515 nm, the laser beam 21 is double-pulsed, and the pulse width is 185 fs. Plot P36 shows the case where the wavelength of the laser light 21 is 515 nm, the pulse width is 1.0 ps, ​​and the substrate 10 is made of urea resin.

[0058] 17, it can be seen that when the substrate 10 is made of paper phenolic resin, the G / D ratio is significantly higher and the resistance value is lower than when the substrate 10 is made of urea resin. This is thought to be because the paper phenolic resin containing benzene rings has good crystallinity after processing and sufficient formation of six-membered rings.

[0059] FIG. 18 shows the fluence (J / cm) of the laser light 21. ２ 18 is a graph showing the relationship between the resistance (Ω) of the conductive portion 13 and the temperature (Tc) of the substrate 10. In FIG. 18, plot P41 shows the case where the substrate 10 is made of glass epoxy resin, and plot P42 shows the case where the substrate 10 is made of urea resin. Part (a) of FIG. 18 shows the results when using laser light 21 with a wavelength of 1030 nm and a pulse width of 1.0 ps. Part (b) of FIG. 18 shows the results when using laser light 21 with a wavelength of 515 nm and a pulse width of 1.0 ps.

[0060] In this experiment, the conductivity of the glass epoxy resin was increased by 10 －１３ From 2.3 x 10 １The reason why the change in conductivity is larger in the glass epoxy resin than in the urea resin is thought to be that, like the phenolic resin, the benzene ring 15 contributes greatly to the improvement in conductivity due to irradiation with the laser beam 21.

[0061] FIG. 19 is a graph showing the results of Raman analysis of a workpiece modified by irradiation with laser light 21. Parts (a) to (d) of FIG. 19 show Raman spectrum waveforms when the substrate 10 is made of glass epoxy resin. Part (a) of FIG. 19 shows the results of analysis of workpieces with different wavelengths and resistance values ​​of the laser light 21 when the pulse width of the laser light 21 is 185 fs. Part (b) of FIG. 19 shows the results of analysis of workpieces with different resistance values ​​when the pulse width of the laser light 21 is 1.0 ps. Part (c) of FIG. 19 shows the results of analysis of workpieces with different processing conditions, only the wavelength of the laser light 21, when the pulse width of the laser light 21 is 1.0 ps. Part (d) of FIG. 19 shows the results of analysis of workpieces with different processing conditions, only the number of pulses of the laser light 21, when the pulse width of the laser light 21 is 185 fs.

[0062] As is clear from a comparison of parts (a) to (d) of Figure 19 with part (b) of Figure 16, the Raman spectrum waveform of the processed part in the glass epoxy resin is significantly different from the Raman spectrum waveform of the processed part in the urea resin. This means that the composition of the product in the processed part in the glass epoxy resin is significantly different from the composition of the product in the processed part in the urea resin.

[0063] FIG. 20 is a graph showing the relationship between the G / D ratio and the resistance value (Ω). In FIG. 20, plots P52 to P55 show the case where the substrate 10 is made of glass epoxy resin. Plot P52 shows the case where the wavelength of the laser beam 21 is 515 nm and the pulse width is 185 fs. Plot P53 shows the case where the wavelength of the laser beam 21 is 515 nm and the pulse width is 1.0 ps. Plot P54 shows the case where the wavelength of the laser beam 21 is 1030 nm and the pulse width is 1.0 ps. Plot P55 shows the case where the wavelength of the laser beam 21 is 515 nm, the laser beam 21 is double-pulsed, and the pulse width is 185 fs. Plot P56 shows the case where the wavelength of the laser beam 21 is 515 nm and the pulse width is 1.0 ps, ​​and the substrate 10 is made of urea resin.

[0064] 20, it can be seen that even when the substrate 10 is made of glass epoxy resin, the G / D ratio is significantly higher and the resistance value is lower than when the substrate 10 is made of urea resin. This is thought to be because the glass epoxy resin containing benzene rings has good crystallinity after processing and sufficient formation of six-membered rings.

[0065] Third Example Next, an example will be described in which the substrate 10 contains 50 mass percent wood flour. Fig. 21 shows the relationship between the irradiation pitch (µm) and the fluence (J / cm) of the laser beam 21 when the conductive portion 13 is formed by irradiating the substrate 10 made of paper phenolic resin containing 50 mass percent wood flour with the laser beam 21. ２ 1 is a graph showing the relationship between the conductivity (S / m) of the conductive portion 13 and the electrical conductivity (S / m) of the conductive portion 13. In the figure, plot P61 indicates no conduction (electrical conductivity less than 0.01 S / m), plot P62 indicates a conductivity of 0.01 S / m or more but less than 10 S / m, plot P63 indicates a conductivity of 10 S / m or more but less than 100 S / m, plot P64 indicates a conductivity of 100 S / m or more, and plot P65 indicates a conductivity of 1000 S / m or more.

[0066] For comparison, part (a) of Fig. 21 shows the case where the substrate 10 is made of paper phenolic resin containing no wood flour. Part (b) of Fig. 21 shows the case where the substrate 10 is made of paper phenolic resin containing 50 mass percent wood flour. Parts (a) and (b) of Fig. 21 show the results when laser light 21 with a wavelength of 515 nm was used.

[0067] 21(b) with (a) of Fig. 21(a), it can be seen that whether the wavelength of the laser light 21 is 515 nm or 343 nm, the inclusion of wood flour in the substrate 10 improves the conductivity of the conductive portion 13. In particular, the conductivities of the two plots P65 included in (b) of Fig. 21(a) were significantly high, at 1613 S / m (irradiation pitch 1.0 μm) and 1471 S / m (irradiation pitch 0.5 μm), respectively.

[0068] This result is thought to be affected by the wood flour content, but is thought to be at least obtainable if the substrate 10 contains wood flour. In addition, this result is thought to be similarly obtainable even when the substrate 10 contains plant flour other than wood flour. In addition, this result is thought to be similarly obtainable even when the substrate 10 is made of a thermosetting resin other than paper phenolic resin, for example, glass epoxy resin. In addition, this result is thought to be affected by the wavelength of the laser light 21, but is thought to be obtainable regardless of the wavelength of the laser light 21 as long as the substrate 10 contains wood flour.

[0069] Fourth Example Next, an example will be described in which a spiral inductor is formed by irradiating a substrate 10 made of paper phenolic resin with laser light 21. FIG. 22 is a diagram showing the irradiation conditions of the laser light 21 in this example. FIG. 23 is a diagram showing the calculated and measured inductance values ​​for four spiral inductors A to D. Of these, spiral inductors A to C are spiral inductors consisting of conductive portions 13 formed by irradiating a substrate 10 with laser light 21. Spiral inductor D is a comparative example, a spiral inductor obtained by winding a coated copper wire. The calculated values ​​also include the winding length. The measured values ​​also include the number of turns, diameter (average value), and wire spacing.

[0070] As shown in FIG. 23, in spiral inductors A to C, the inductance increased as the winding diameter increased. However, unlike spiral inductor D according to the comparative example, the measured inductance value was significantly larger than the calculated inductance value. For example, the measured value (3400 μH) in spiral inductor C was approximately 1100 times the measured value (3 μH) in spiral inductor D using copper wire. In other words, a spiral inductor using conductive portion 13 can be made significantly smaller (by reducing the number of windings and winding diameter) than a spiral inductor using copper wire. Furthermore, in this example, the fluence of laser light 21 was 0.83 mJ / cm ２ In this way, when the fluence of the laser light 21 is 0.1 mJ / cm ２ If the above conditions are met, it is possible to obtain a conductive portion 13 with excellent conductivity. This is presumably also true when the substrate 10 contains an epoxy resin.

[0071] Fifth Example Next, an example will be described in which a capacitor is formed by irradiating a substrate 10 made of paper phenolic resin with laser light 21. FIG. 24 is a plan view showing the shape of the capacitor fabricated in this example. This capacitor is formed by a pair of opposing comb-shaped conductive portions 13. FIG. 25 is a table showing the calculated and measured capacitance values ​​for two capacitors E and F. Capacitors E and F are capacitors formed by irradiating a substrate 10 with laser light 21 with conductive portions 13. The calculated values ​​are also shown with the relative dielectric constant. The measured values ​​are also shown with the number of opposing faces, length, inter-line distance, and opposing area for each of the branch and trunk portions. The irradiation conditions for the laser light 21 are the same as those for the fourth example (see FIG. 22).

[0072] As shown in FIG. 25, a sufficiently large capacitance was obtained in capacitors E and F. In capacitors E and F, the capacitance increased as the opposing area increased and the inter-line distance decreased. Generally, capacitance occurs when a pair of conductors are spaced apart. Therefore, the shape of the conductive portion 13 serving as a capacitor is not limited to a comb-like shape. Also in this example, the fluence of the laser light 21 was 0.83 mJ / cm. ２ In this way, when the fluence of the laser light 21 is 0.1 mJ / cm ２ If the above conditions are met, it is possible to obtain a conductive portion 13 with excellent conductivity. This is presumably also true when the substrate 10 contains an epoxy resin.

[0073] The electronic component manufacturing method and electronic component according to the present disclosure are not limited to the above-described embodiment, and various other modifications are possible. For example, while the above embodiment illustrates a case in which the substrate 10 contains a phenolic resin or a glass epoxy resin, the substrate 10 may contain both a phenolic resin and a glass epoxy resin, or may contain a thermosetting resin having a benzene ring in its structure other than a phenolic resin or a glass epoxy resin. The plant flour may include plant flour other than wood flour and bamboo flour (e.g., grass, leaves, stems, or roots).

[0074] While the principles of the present invention have been illustrated and described in preferred embodiments, it will be recognized by those skilled in the art that the present invention can be modified in arrangement and detail without departing from such principles. The present invention is not limited to the particular constructions disclosed herein. We therefore claim all modifications and variations that come within the scope and spirit of the following claims.

[0075] 8...electronic component, 10...substrate, 11...surface, 13...conductive portion, 15...benzene ring, 21...laser light, 31...capacitor, 32...spiral inductor, 33...input terminal, 34...output terminal, 35...reference potential line, 36...antenna.

Claims

1. A method for manufacturing an electronic component, comprising the step of irradiating a substrate containing a thermosetting resin having a benzene ring in its structure with laser light to modify the thermosetting resin, thereby forming a conductive portion containing one or both of graphene and graphite on a surface of the substrate, inside the substrate, or both on the surface and inside of the substrate.

2. The method for manufacturing an electronic component according to claim 1, wherein the thermosetting resin includes at least one of an epoxy resin and a phenolic resin.

3. The method for manufacturing an electronic component according to claim 1 or 2, wherein the wavelength of the laser light is 200 nm or more and 1100 nm or less.

4. The method for manufacturing an electronic component according to any one of claims 1 to 3, wherein the laser light is pulsed light, and the pulse width of the laser light is 100 femtoseconds or more and 2 picoseconds or less.

5. The wavelength of the laser light is 200 nm or more and 520 nm or less, the pulse width of the laser light is 100 femtoseconds or more and 200 femtoseconds or less, and the fluence of the laser light is 4 J / cm ２ The method for manufacturing an electronic component according to claim 2 .

6. The fluence of the laser light is 0.1 mJ / cm ２ The method for manufacturing an electronic component according to claim 2 .

7. The method for manufacturing an electronic component according to any one of claims 1 to 6, wherein the irradiation pitch of the laser light is 0.5 μm or less.

8. The method for manufacturing an electronic component according to any one of claims 1 to 7, wherein the substrate further contains plant powder dispersed in the thermosetting resin.

9. An electronic component comprising: a substrate containing a thermosetting resin having a benzene ring in its structure; and a conductive portion provided on a surface of the substrate, inside the substrate, or both on the surface and inside of the substrate, the conductive portion containing one or both of graphene and graphite derived from the thermosetting resin.

10. The electronic component according to claim 9, which is a circuit board, the base material is a substrate, and the conductive portion is a wiring pattern.

11. The electronic component according to claim 9 or 10, wherein the thermosetting resin includes at least one of an epoxy resin and a phenolic resin.

12. The electronic component according to any one of claims 9 to 11, wherein the substrate further contains vegetable powder dispersed in the thermosetting resin.

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