Method for manufacturing module component, and module component

Abstract

To achieve both a reduction of discoloration of a conductive layer and a guarantee of an electromagnetic wave shield function.SOLUTION: A method for manufacturing a module component includes the steps of: arranging a conductive layer electrically connected to ground wiring on an electronic component; arranging, on the conductive layer, a protective layer having a surface resistivity three or more digits higher than the surface resistivity of the conductive layer; measuring the sheet resistance of the conductive layer after arranging the protective layer; and when a measured value of the sheet resistance of the conductive layer is lower than a predetermined threshold, determining that electromagnetic wave shield performance of the conductive layer is acceptable.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a module component, and to a module component. [Background technology]

[0002] In modular components such as electronic circuit boards, electronic components with functional layers, and electronic circuit boards with encapsulating resin layers, there is a growing demand for high-performance electromagnetic wave shielding to accommodate high frequencies such as 5G, as integration and speed increase. The range of industrial applications is expanding due to the widespread use of portable electronic devices and the electrification and electrification of automobiles.

[0003] For example, Patent Document 1 discloses that a conductive layer is used to suppress leakage of electromagnetic waves, and that the conductive layer is covered with a protective layer that has excellent corrosion resistance and migration resistance. Summary of the Invention [Problem to be solved by the invention]

[0004] Conductive layers containing metals such as Cu or Ag and having electromagnetic wave shielding properties may discolor due to oxidation, sulfidation, or the like. Discoloration of the conductive layer may impair the aesthetic appearance of the module component. If the conductive layer is covered with a protective layer to prevent discoloration, the electromagnetic wave shielding performance of the conductive layer cannot be inspected, making it difficult to guarantee the electromagnetic wave shielding performance. Patent Document 1 does not disclose how to guarantee the electromagnetic wave shielding performance of the conductive layer after it has been covered with a protective layer.

[0005] An object of the present invention is to simultaneously reduce discoloration of the conductive layer and ensure electromagnetic wave shielding performance. [Means for solving the problem]

[0006] A method for manufacturing a module component according to one embodiment of the present invention includes the steps of: arranging, on an electronic component, a conductive layer electrically connected to a ground wiring; arranging, on the conductive layer, a protective layer having a surface resistivity three or more orders of magnitude higher than that of the conductive layer; measuring the sheet resistance of the conductive layer after arranging the protective layer; and determining that the electromagnetic shielding performance of the conductive layer is acceptable if the measured sheet resistance of the conductive layer is lower than a predetermined threshold value. [Effects of the Invention]

[0007] According to the present invention, it is possible to reduce discoloration of the conductive layer while ensuring electromagnetic wave shielding performance. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view showing a module component according to a first embodiment of the present invention. [Figure 2] 3 is a flowchart showing a method for manufacturing a modular component according to the first embodiment of the present invention. [Figure 3] FIG. 1 is a diagram showing a method for measuring sheet resistance using a four-probe method. [Figure 4] FIG. 2 is a diagram showing a first example of an electrode used in sheet resistance measurement. [Figure 5] FIG. 10 is a diagram showing a second example of an electrode used in sheet resistance measurement. [Figure 6] FIG. 10 is a diagram showing a third example of an electrode used in sheet resistance measurement. [Figure 7] FIG. 10 is a diagram showing a fourth example of an electrode used in sheet resistance measurement. [Figure 8] 10A and 10B are diagrams showing how the sheet resistance of a conductive layer is measured by a single-pole eddy current measuring instrument in the manufacturing method of a module component according to the second embodiment of the present invention. [Figure 9] FIG. 10 is a diagram showing how the sheet resistance of a conductive layer is measured using a two-pole eddy current measuring instrument. [Figure 10] FIG. 1 is a diagram showing a calibration curve used in measuring sheet resistance using a single-pole eddy current measuring instrument. [Figure 11]10A and 10B are diagrams showing how the sheet resistance of a conductive layer is measured by an LCR meter in the manufacturing method of a module component according to the third embodiment of the present invention. [Figure 12] FIG. 1 is a schematic perspective view showing module components according to Examples 1 to 9. DETAILED DESCRIPTION OF THE INVENTION

[0009] A module component manufacturing method and a module component according to an embodiment of the present invention will be described in detail with reference to the drawings. However, the following embodiments are merely examples of the module component manufacturing method and the module component according to an embodiment of the present invention, and are not limited to the following.

[0010] Unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of components described in the embodiments of the present invention are not intended to limit the scope of the embodiments of the present invention, but are merely illustrative examples. The sizes, positional relationships, etc. of components shown in each drawing may be exaggerated for clarity. In the following description, the same names and symbols indicate the same or similar components, and detailed descriptions will be omitted as appropriate. "Arranged" does not only refer to direct contact, but also includes indirect arrangement, for example, via other components.

[0011] [First embodiment] <Configuration of module component according to the first embodiment of the present invention> The configuration of a module component according to a first embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a schematic cross-sectional view showing an example of a module component 1 according to a first embodiment of the present invention. Fig. 1 shows a cross-section of the module component 1 including an electronic component 11, a conductive layer 12, and a protective layer 13 in the module component 1.

[0012] The module component 1 includes an electronic component 11, a conductive layer 12 disposed on the electronic component 11, and a protective layer 13 disposed on the conductive layer 12, the protective layer 13 having a surface resistivity three or more orders of magnitude higher than that of the conductive layer 12. The module component 1 shown in FIG. 1 also includes a substrate 15 on which the electronic component 11 is mounted, and a sealing resin layer 16 that seals the electronic component 11. The conductive layer 12 is disposed on the electronic component 11 via the sealing resin layer 16. The conductive layer 12 covers at least a portion of the side surfaces of the sealing resin layer 16 and the substrate 15. The module component 1 does not necessarily have to include the sealing resin layer 16.

[0013] The substrate 15 is a laminated circuit board on which the electronic components 11 are mounted via solder or the like. However, the substrate 15 is not limited to being laminated, and can be modified as appropriate depending on the specifications of the module component 1, etc. Furthermore, the number of layers of the laminated substrate 15, the size of the substrate 15, etc. can be modified as appropriate depending on the specifications of the module component 1, etc. The substrate 15 has a ground wiring 14. The ground wiring 14 is arranged on the outer periphery of the substrate 15 so as to be exposed on the side surface thereof.

[0014] The electronic component 11 includes at least one of a semiconductor integrated circuit, a resistor, a capacitor, a light-emitting element, a light-receiving element, etc. Examples of the semiconductor integrated circuit include an IC (Integrated Circuit) and an LSI (Large Scale Integration). The number of electronic components 11 mounted on the substrate 15 is not limited to one, and any number can be selected depending on the specifications of the module component 1, etc. When multiple electronic components 11 are mounted on the substrate 15, the multiple electronic components 11 may have the same specifications, or at least one electronic component 11 may have a different specification. The top surface 11a in FIG. 1 is the top surface of the electronic component 11.

[0015] The conductive layer 12 has functions such as heat dissipation, static electricity countermeasures, and EMI (Electromagnetic Interference) countermeasures by shielding electromagnetic waves. The conductive layer 12 is made of a metal material with low resistivity to shield electromagnetic waves. For example, the conductive layer 12 can be made of an alloy such as Au, Ag, Cu, Al, stainless steel (SUS), or nickel. The conductive layer 12 is disposed so as to cover a part of the side surface of the substrate 15. The conductive layer 12 is electrically connected to the ground wiring 14. The upper surface 12a in FIG. 1 is the upper surface of the conductive layer 12.

[0016] The conductive layer 12 shields the module component 1 from electromagnetic waves incident from the outside and from electromagnetic waves emitted from within the module component 1. By shielding the electromagnetic waves incident from the outside with the conductive layer 12, the module component 1 can reduce noise, stabilize the operation of the module component 1, and prevent malfunctions. Furthermore, by shielding the electromagnetic waves emitted from the inside with the conductive layer 12, the module component 1 can reduce noise emitted to the outside, stabilize the operation of devices or components other than the module component 1, and prevent malfunctions. The thickness of the conductive layer 12 is preferably set based on the resistivity of the conductive layer 12. For example, the thickness of the conductive layer 12 is preferably set so that the sheet resistance, calculated by dividing the resistivity of the conductive layer 12 by its thickness, is 0.5 Ω or less. Setting the sheet resistance of the conductive layer 12 to 0.5 Ω or less can improve the electromagnetic wave shielding performance.

[0017] For example, when the conductive layer is made of Cu, it may oxidize and discolor in high-temperature environments such as solder reflow. The thickness of oxidation of Cu or other materials ranges from a few nanometers to a few tens of nanometers, and this is observed as a color change such as brown or blue. Slight differences in the progress of oxidation can also be observed as color unevenness. Furthermore, when the conductive layer is made of Ag, Ag is resistant to thermal oxidation, but may turn brown over time due to sulfurization. Furthermore, not only Cu and Ag but also binders, additives, impurities, etc. can cause discoloration.

[0018] Discoloration of the conductive layer can detract from the aesthetic appearance of electronic components. Also, color unevenness can give users the impression that the quality of module components is inconsistent. Furthermore, module components may be provided with information to identify the module components, such as the production lot number. If the conductive layer discolors severely, it can become difficult to read the information.

[0019] On the other hand, Patent Document 1 discloses covering a conductive layer with a protective layer that has excellent corrosion resistance and migration resistance. However, when a conductive layer is covered with a protective layer, the electrical resistance of the protective layer is high, making it difficult to measure the sheet resistance of the conductive layer from above the protective layer. This makes it impossible to inspect the electromagnetic wave shielding function of the conductive layer, making it difficult to guarantee the electromagnetic wave shielding function. Patent Document 1 does not disclose how to guarantee the electromagnetic wave shielding function of the conductive layer after covering it with a protective layer.

[0020] The module component 1 according to the first embodiment of the present invention has a protective layer 13 disposed on the conductive layer 12, the protective layer 13 having a surface resistivity three or more orders of magnitude higher than that of the conductive layer 12. For example, the protective layer 13 is formed of an insulating material such as a resin material. In the module component 1, the provision of the protective layer 13 can reduce oxidation of Cu, sulfurization of Ag, corrosion, and the like that constitute the conductive layer 12.

[0021] Furthermore, the protective layer 13 has an opening 130 that exposes a portion of the conductive layer 12. In the module component 1, the sheet resistance of the conductive layer 12 can be measured by bringing an electrode into contact with the portion of the conductive layer 12 exposed by the opening 130. By measuring the sheet resistance, which shows a high correlation with the electromagnetic shielding performance, the electromagnetic shielding performance of the conductive layer 12 can be measured and evaluated with the protective layer 13 in place. This makes it possible in the module component 1 to both reduce discoloration of the conductive layer 12 and ensure the electromagnetic shielding performance.

[0022] <Method of manufacturing module component 1 according to the first embodiment of the present invention> A method for manufacturing a module component 1 according to a first embodiment of the present invention will be described with reference to FIGS. 2 to 7. FIG. 2 is a flowchart showing an example of a method for manufacturing a module component 1 according to the first embodiment of the present invention. FIG. 3 is a diagram showing an example of a method for measuring sheet resistance using a four-probe method. FIG. 4 is a diagram showing a first example of an electrode used in sheet resistance measurement. FIG. 5 is a diagram showing a second example of an electrode used in sheet resistance measurement. FIG. 6 is a diagram showing a third example of an electrode used in sheet resistance measurement. FIG. 7 is a diagram showing a fourth example of an electrode used in sheet resistance measurement. FIGS. 4 to 7 show the tip portions of the electrodes that make up the probes.

[0023] The manufacturing method of the module component 1 includes a step (S11) of arranging a conductive layer 12 on the electronic component 11, a step (S12) of arranging a protective layer 13 on the conductive layer 12, a step (S13) of measuring the sheet resistance of the conductive layer 12, and a step (S14) of determining that the electromagnetic wave shielding performance of the conductive layer 12 is acceptable.

[0024] (S11: Step of disposing conductive layer 12 on electronic component 11) In the process of disposing the conductive layer 12 on the electronic component 11, the conductive layer 12 electrically connected to the ground is disposed on the electronic component 11. For example, a liquid ejection head can be used in the process of disposing the conductive layer 12 on the electronic component 11. Specifically, a liquid containing a material constituting the conductive layer 12 is ejected from the liquid ejection head while changing the relative position of the liquid ejection head and the module component 1 in a direction along the upper surface 11a of the electronic component 11, thereby disposing the conductive layer 12 on the upper surface 11a of the electronic component 11. The liquid ejection head has a nozzle, a liquid chamber communicating with the nozzle and containing the liquid, and a pressure generating unit that applies pressure to the liquid in the liquid chamber. The liquid ejection head ejects the liquid from the nozzle by applying pressure to the liquid in the liquid chamber using the pressure generating unit. Note that the process of disposing the conductive layer 12 on the electronic component 11 is not limited to a liquid ejection head, and sputtering, plating, a jet dispenser, or the like may also be used.

[0025] (S12: Step of disposing protective layer 13 on conductive layer 12) In the step of disposing the protective layer 13 on the conductive layer 12, the protective layer 13 having a surface resistivity three or more orders of magnitude higher than that of the conductive layer 12 is disposed on the conductive layer 12. In the step of disposing the protective layer 13 on the conductive layer 12, a liquid ejection head can be used, as in S11. Specifically, a liquid containing a material constituting the protective layer 13 is ejected from the liquid ejection head while changing the relative position between the liquid ejection head and the module component 1 in the direction along the upper surface 12a of the conductive layer 12, to dispose the protective layer 13 on the upper surface 12a of the conductive layer 12. By disposing the protective layer 13 using the liquid ejection head, the opening 130 can be easily formed at any position in the protective layer 13. Note that the method of disposing the conductive layer 12 on the electronic component 11 is not limited to a liquid ejection head, and a coater or the like may also be used.

[0026] (S13: Step of measuring sheet resistance of conductive layer 12) In the step of measuring the sheet resistance of the conductive layer 12, the protective layer 13 is disposed on the conductive layer 12, and then the sheet resistance of the conductive layer 12 is measured. The sheet resistance can be measured, for example, by a four-probe method. In the module component 1 shown in FIG. 1 , the opening 130 includes four through-holes that penetrate the protective layer 13 so that four electrodes used in the four-probe method can be brought into contact with the conductive layer 12. The sheet resistance can be measured by bringing the four electrodes into contact with portions of the conductive layer 12 exposed by the four through-holes. However, the number of electrodes used in measuring the sheet resistance is not limited to four; a minimum of two is sufficient. Therefore, the opening 130 only needs to include a minimum of two through-holes.

[0027] In the four-probe method shown in Figure 3, current I is passed between electrodes 20a and 20d, and the potential difference V between electrodes 20b and 20c is measured. The sheet resistance is calculated by multiplying the ratio of these values ​​by a correction coefficient RCF. When the volume resistivity ρv of the metal bulk is known, the sheet resistance ρs can be calculated using the following equation: where t is the thickness of the conductive layer 12. ρv=RCF×t×V / I=ρs×t

[0028] When using Ag or Cu paste or ink as the material for the conductive layer 12, the volume resistance of the paste or ink changes depending on the firing conditions of its components, so it is preferable to calculate the surface resistivity ρs using the following formula. ρs=RCF×V / I

[0029] Each of electrodes 20a to 20d can be a PSP electrode manufactured by Nitto Seiko Analytech, Inc., having the shape shown in FIG. 4. While electrode 20a is shown as a representative electrode in FIGS. 4 to 7, the electrodes shown in FIGS. 4 to 7 can be used for any of electrodes 20a to 20d. For example, the diameter of the cylindrical portion of electrodes 20a to 20d is 0.52 mm, the radius of the tip portion of electrodes 20a to 20d is 0.26 mmR, and the pressing load of electrodes 20a to 20d on conductive layer 12 is 240 gf for the entire electrode. A low resistivity meter, Loresta AX (MCP-T370) manufactured by Nitto Seiko Analytech, Inc., can be used as a measuring device that receives the output signal from each of electrodes 20a to 20d and outputs the resistance measurement results.

[0030] The shape of the tip portion of each of electrodes 20a to 20d is not limited to the cylindrical end shape shown in Fig. 4, and may be various shapes such as the hemispherical shape shown in Fig. 5, the hemispherical shape with the arched portion removed shown in Fig. 6, or the pointed shape shown in Fig. 7. Each of electrodes 20a to 20d may have the same tip shape, or at least some of electrodes 20a to 20d may have different tip shapes.

[0031] (S14: Step of determining that the electromagnetic wave shielding performance of the conductive layer 12 is acceptable) In the step of determining whether the electromagnetic shielding performance of the conductive layer 12 is acceptable, if the measured value of the sheet resistance of the conductive layer 12 measured in S14 is lower than a predetermined threshold, the electromagnetic shielding performance of the conductive layer 12 is determined to be acceptable. The threshold for determining whether the performance is acceptable can be set appropriately depending on the type of the conductive layer 12.

[0032] As described above, in the manufacturing method for module component 1 according to the first embodiment of the present invention, by disposing protective layer 13 on conductive layer 12, it is possible to reduce exposure of conductive layer 12 and reduce discoloration of conductive layer 12. Furthermore, with protective layer 13 disposed on conductive layer 12, the sheet resistance of conductive layer 12 is measured, and if the sheet resistance is lower than a threshold value, the electromagnetic shielding performance of conductive layer 12 is determined to be acceptable, thereby ensuring the electromagnetic shielding performance of conductive layer 12. As described above, the manufacturing method for module component 1 according to the first embodiment of the present invention can achieve both reduced discoloration of conductive layer 12 and guaranteed electromagnetic shielding performance.

[0033] In the first embodiment of the present invention, in the step of measuring the sheet resistance of the conductive layer 12, the sheet resistance of the conductive layer 12 is measured using an electrode that contacts a part of the conductive layer 12 that is exposed through the opening 130 of the protective layer 13. This makes it possible to easily measure the sheet resistance of the conductive layer 12 in a state where the protective layer 13 is disposed on the conductive layer 12.

[0034] In the first embodiment of the present invention, the protective layer 13 is not limited to one including the opening 130. For example, the protective layer 13 may be disposed over the entire upper surface 12a of the conductive layer 12, and in the step of measuring the sheet resistance of the conductive layer 12, the sheet resistance of the conductive layer 12 may be measured using a pointed electrode that penetrates the protective layer 13 and contacts the conductive layer 12. This simplifies the manufacturing process by eliminating the need for the opening 130 in the protective layer 13, and prevents discoloration of the conductive layer 12 exposed through the opening 130. The pointed electrode may have a shape, for example, as shown in FIG. 7. From the viewpoint of minimizing the area of ​​the conductive layer 12 exposed from the protective layer 13 due to a hole formed when the pointed electrode is pierced, the pointed electrode preferably has a needle-like shape with a small cross-sectional area perpendicular to the longitudinal direction.

[0035] [Second embodiment] Next, a method for manufacturing a module component according to a second embodiment of the present invention will be described. Note that the same names and symbols as those in the previously described embodiments indicate the same or similar components or configurations, and detailed descriptions will be omitted where appropriate. This also applies to the following embodiments.

[0036] A method for manufacturing a module component 1 according to a second embodiment of the present invention will be described with reference to Figs. 8 to 10. Fig. 8 is a diagram showing an example of how the sheet resistance of a conductive layer 12 is measured by a monopole eddy current measurement device 21 in the method for manufacturing a module component 1 according to the second embodiment of the present invention. Fig. 9 is a diagram showing an example of how the sheet resistance of a conductive layer 12 is measured by a two-pole eddy current measurement device 21X. Fig. 10 is a diagram showing an example of a calibration curve used in sheet resistance measurement by a monopole eddy current measurement device 21.

[0037] In the second embodiment of the present invention, the protective layer 13 is disposed over the entire upper surface 12a of the conductive layer 12, and the main difference from the first embodiment is that in the step of measuring the sheet resistance of the conductive layer 12, the sheet resistance of the conductive layer 12 is measured using a monopole eddy current measuring instrument 21. "The protective layer 13 is disposed over the entire upper surface 12a of the conductive layer 12" means that the upper surface 12a of the protective layer 13 does not have any openings.

[0038] For example, an eddy current film thickness meter can be used as the monopole eddy current measuring instrument 21. The eddy current film thickness meter is a film thickness meter that complies with DIN EN ISO 2360 and measures the thickness of an insulating film on a metal by utilizing the electrical correlation between the magnitude of eddy currents induced on a non-magnetic metal surface by a high-frequency electric field, the magnetic field, and the distance from the metal surface (film thickness).

[0039] The monopole eddy current measuring instrument 21 has a probe 211 equipped with a coil 212 that generates an AC magnetic field using a high-frequency AC current Ip (e.g., 2 MHz or higher). When the probe 211 is brought close to a conductive non-magnetic metal surface, the high-frequency AC current generates an eddy current on the metal surface. Because the eddy current flows in a direction that cancels out the magnetic field, the current from the high-frequency AC Ip transmitter is resisted. The magnitude of the resistance is correlated with the characteristics of the base metal plate and the distance (film thickness) from the probe 211, and can be converted into film thickness. Here, the metal plate characteristics refer to the resistance to eddy current flow, which corresponds to the volume resistivity and thickness of the metal plate, i.e., sheet resistance. Therefore, if the thickness of the protective layer 13 is constant, there is a correlation between the output of the monopole eddy current measuring instrument 21 and the sheet resistance of the conductive layer 12 located below the protective layer 13. Therefore, the sheet resistance of the conductive layer 12 can be measured based on the output of the monopole eddy current measuring instrument 21.

[0040] 9 is used, the AC magnetic field Bh generated by the two-pole eddy current measuring instrument 21X acts reliably on the ground wiring 14 of the module component 1, so that the ground wiring 14 is located within the measurement range of the two-pole eddy current measuring instrument 21X. Therefore, due to the influence of the sheet resistance of the ground wiring 14, which is nearly two orders of magnitude lower than that of the conductive layer 12, the sheet resistance of the conductive layer 12 may not be measured accurately.

[0041] In the monopole eddy current measurement instrument 21, the range in which the AC magnetic field Bh generated by the monopole eddy current measurement instrument 21 acts is determined by the size and material (magnetic permeability) of the probe 211 including the coil 212. Some monopole eddy current measurement instruments 21 have a measurement range of 0 mm to 0.6 mm or 0 mm to 2 mm, for example. In the second embodiment of the present invention, by not positioning the ground wiring 14 within these measurement ranges, the sheet resistance of the conductive layer 12 can be measured with high accuracy without being affected by the sheet resistance of the ground wiring 14.

[0042] Depending on the shape of the module component 1, the ground wiring 14 may be located near the measurement range of the monopole eddy current measurement instrument 21, or a portion of the ground wiring 14 may be located within the measurement range of the monopole eddy current measurement instrument 21. In these cases, the measurement of the sheet resistance of the conductive layer 12 may be affected by the ground wiring 14. In the second embodiment of the present invention, in such cases, a calibration curve such as that shown in FIG. 10 is obtained in advance, thereby reducing the effect of the ground wiring 14 on the measurement of the sheet resistance of the conductive layer 12.

[0043] FIG. 10 is a graph showing a calibration curve obtained by measuring the sheet resistance of a conductive film fabricated on a glass substrate using the four-point probe method and a low resistivity meter, Loresta AX (MCP-T370), and recording the film thickness readings measured with an eddy current film thickness meter (Sankou Electronics Laboratory Co., Ltd., probe: SNFe-0.6, main body: SWT-NEOII). The SNFe-0.6 probe used has the smallest measurement range of any commercially available product, from 0 mm to 0.6 mm. A high correlation was obtained, with virtually no difference in the film thickness readings, regardless of whether or not copper foil corresponding to the ground wiring 14 was present. Specifically, the correlation between the film thickness measured with the eddy current film thickness meter and the sheet resistance yielded a coefficient of determination R2 of 0.9933. Note that plot A in FIG. 10 represents the case where there is no copper foil corresponding to the ground wiring 14, while plot B represents the case where there is copper foil corresponding to the ground wiring 14.

[0044] Furthermore, the monopole eddy current measurement device 21 can measure the sheet resistance of the conductive layer 12 without contacting the protective layer 13. This allows the sheet resistance of the conductive layer 12 to be measured without scratching or otherwise damaging the protective layer 13. Furthermore, the sheet resistance of the conductive layer 12 can be measured without providing an opening in the protective layer 13 to expose the conductive layer 12. However, in the second embodiment of the present invention, the probe 211 of the monopole eddy current measurement device 21 may be brought into contact with the protective layer 13 to measure the sheet resistance of the conductive layer 12. Furthermore, in the second embodiment of the present invention, the device is not limited to the monopole eddy current measurement device 21, and a two-pole eddy current measurement device 21X may also be used.

[0045] [Third embodiment] Next, a method for manufacturing a module component according to a third embodiment of the present invention will be described. Fig. 11 is a diagram showing an example of how the sheet resistance of conductive layer 12 is measured by LCR meter 30 in the method for manufacturing module component 1 according to the third embodiment of the present invention.

[0046] In the third embodiment of the present invention, the protective layer 13 is disposed over the entire upper surface 12a of the conductive layer 12, and in the step of measuring the sheet resistance of the conductive layer 12, the sheet resistance of the conductive layer 12 is measured based on a measurement value of at least one of the capacitance value and the resistance value including the protective layer 13 by the LCR meter 30, which is different from the first embodiment of the present invention.

[0047] The LCR meter 30 is a measuring instrument that measures impedance by applying an AC voltage to the module component 1, and also measures the resistance (R) component and capacitance (C) component from the phase difference. The C component is determined by the dielectric constant and thickness of the protective layer 13, and the R component of the conductive layer 12 can be obtained.

[0048] 11 shows an example of measurement performed by the four-probe method in which copper foil 40 is attached to a resin block 50 at equal intervals and the resin block 50 is pressed against the protective layer 13 of the module component 1 at approximately 200 gf. The LCR meter 30 may be, for example, an LCR meter ZM2376 manufactured by NF Corporation.

[0049] [Comparative Examples and Examples] Next, comparative examples and examples will be described. However, the present invention is not limited to the examples shown below. Fig. 12 is a schematic perspective view showing module components 1 according to comparative examples and examples 1 to 7. In Fig. 12, module component 1-1 represents the comparative example, module component 1-2 represents example 1, module component 1-3 represents example 2, module component 1-4 represents example 3, and module component 1-5 represents example 4. Furthermore, module component 1-6 represents example 5, module component 1-7 represents example 6, and module component 1-8 represents example 7.

[0050] In the comparative example and Examples 1 to 7, a conductive layer 12 made by baking a Cu paste and an Ag paste was disposed on the electronic component. In Examples 1 to 7, a protective layer 13 made of a solder resist resin that had been UV-cured and thermally cured at 150°C for 10 minutes was further disposed on the conductive layer. In these module components 1, the thickness of the sealing resin layer was 2 mm in Examples 1-1, 1-2, and 1-4 to 1-7, and 1 mm in Example 1-3. The thickness refers to the height in the normal direction to the top surface of the electronic component 11 in the module component 1.

[0051] The module components 1 according to the comparative example and examples 1 to 7 had an outer edge shape in top view of approximately square, with an area of ​​19 mm × 19 mm. In the module components 1 according to examples 1 to 7, the thickness of the conductive layer 12 was changed, and the module components 1 were manufactured with the aim of achieving sheet resistances of 6 mΩ, 10 mΩ, 14 mΩ, and 18 mΩ.

[0052] (Comparative Example) In the comparative example, only the conductive layer 12 was disposed on both the top surface 1-1a and the side surface 1-1b of the module component 1-1, and no protective layer was disposed.

[0053] Example 1 In the module component 1-2 according to the first embodiment, the conductive layer 12 and the protective layer 13 are disposed on both the top surface 1-2a and the side surface 1-2b, respectively.

[0054] Example 2 In the module component 1-3 according to Example 2, the conductive layer 12 was disposed on both the upper surface 1-3a and the side surface 1-3b. In addition, in the module component 1-3, the protective layer 13 was disposed only on the upper surface 1-3a, and not on the side surface 1-3b.

[0055] Table 1 shows the measurement results of the sheet resistance of module component 1-3. In Table 1, the sheet resistance of the conductive layer 12 was measured for targets of 6 mΩ, 10 mΩ, 14 mΩ, and 18 mΩ after the conductive layer 12 was placed, after the protective layer 13 was placed, and after heating at 230°C for 1 minute. The unit of the measured sheet resistance is mΩ. "Pt1" and "Pt2" in Table 1 represent measurement results at different positions on the top surface 1-2a of module component 1-2. Note that the same interpretation applies to the tables shown below.

[0056] [Table 1]

[0057] In Table 1, the measured value of sheet resistance after the conductive layer 12 is disposed is measured by the four-point probe method. The measured values ​​after the protective layer 13 is disposed and after heating at 230°C for 11 minutes are converted from the displayed value D of the thickness measurement result of the monopolar eddy current measuring instrument 21 using the calibration curve expressed by the following formula. ρs=0.0667×D+3.84

[0058] Next, the results of measuring the conductive layer 12 of module component 1-2 using the LCR meter 30 are shown in Table 2. In measurements using the LCR meter 30, an AC voltage was applied to the module component 1 to measure impedance, and the R component and C component were measured from the phase difference. The C component was determined by the dielectric constant and thickness of the protective layer 13, and the R component of the conductive layer 12 was obtained. As shown in Figure 11, copper foil 40 was attached to a resin block 50 at equal intervals, and the resin block 50 was pressed against the protective layer 13 of module component 1-3 at approximately 200 gf, and measurements were made using the four-point probe method. The LCR meter 30 used was the LCR meter ZM2376 manufactured by NF Corporation.

[0059] [Table 2]

[0060] In Table 2, the measured values ​​after the conductive layer 12 was disposed were measured by the four-point probe method. The measured values ​​after the protective layer 13 was disposed and after heating at 230° C. for 11 minutes were obtained from the R component of the LCR meter 30.

[0061] Example 3 The module component 1-4 according to Example 3 is a low-profile module component having a small thickness. In the module component 1-4, conductive layers 12 are disposed on both the top surface 1-4a and the side surfaces 1-4b. In addition, in the module component 1-4, the protective layer 13 is disposed only on the top surface 1-4a, and is not disposed on the side surfaces 1-4b.

[0062] Example 4 In a module component 1-5 according to Example 4, a conductive layer 12 and a protective layer 13 were disposed on both an upper surface 1-5a and a side surface 1-5b, respectively. Eight through-holes, each of which was approximately circular in top view, were provided in the upper surface 1-5a of the protective layer 13 as openings 130 for performing the four-point probe method at two locations.

[0063] The diameter of the through-holes in the open area 130 was approximately 0.6 mm. Four through-holes were provided at two locations with a 1.5 mm pitch. The color of the open area 130 was clearly browner than before heating at 230°C for one minute, but due to its small area, no color unevenness was visible. The sheet resistance could be stably measured by pressing a four-probe electrode through the open area 130.

[0064] The electrodes used were PSP electrodes manufactured by Nitto Seiko Analytech, and the measuring device that receives the output signal from the electrodes and outputs the resistance measurement results was a low resistivity meter Loresta AX (MCP-T370) manufactured by Nitto Seiko Analytech. The diameter of the cylindrical part of the electrode was 0.52 mm, the radius of the tip of the electrode was 0.26 mmR, and the pressing load on the conductive layer 12 of the electrode was 240 gf for the entire electrode. Table 3 shows the measurement results of the sheet resistance of module components 1-5.

[0065] [Table 3]

[0066] Example 5 In a module component 1-6 according to Example 5, a conductive layer 12 and a protective layer 13 were disposed on both an upper surface 1-6a and a side surface 1-6b, respectively. Four linear through-holes, as viewed from above, were provided in the upper surface 1-6a of the protective layer 13 as openings 130 for performing the four-point probe method.

[0067] Example 6 In a module component 1-7 according to Example 6, a conductive layer 12 and a protective layer 13 were disposed on both an upper surface 1-7a and a side surface 1-7b, respectively. Seven through-holes, each of which was approximately circular in top view and aligned in two orthogonal axial directions, were provided in the upper surface 1-7a of the protective layer 13 as openings 130 for performing the four-point probe method.

[0068] Example 7 In the module component 1-8 according to Example 7, a conductive layer 12 and a protective layer 13 were disposed on both the top surface 1-8a and the side surface 1-8b, respectively. Furthermore, through-holes for displaying characters and two-dimensional codes in a top view were provided as openings 130 for performing the four-probe method. In other words, in the module component 1-8, information was provided by the openings 130 provided in the protective layer 13.

[0069] The information provided by the opening 130 is, for example, information about the module component 1. By forming the opening 130 in the protective layer 13, this information can be read as letters, numbers, two-dimensional codes (QR Code (registered trademark)), etc. when viewed in plan.

[0070] In recent years, efforts have been made in the field of mobile devices and the like to miniaturize, thin, and increase the density of modular components placed inside such devices. For such modular components, the importance of displaying information has increased from various perspectives, including the Product Liability Act (PL Act), security to prevent counterfeiting, and traceability. In the modular component 1, various pieces of information about the modular component 1 can be displayed by providing information through the opening 130. Specifically, the information provided through the opening 130 may include legally required information such as the model, specifications, manufacturing date, manufacturer logo, and place of origin of the modular component 1, as well as customer-requested specifications. The information provided through the opening 130 may include alphanumeric characters, non-alphanumeric symbols, or code information. For example, the information provided through the opening 130 can be provided by not providing liquid in the area of ​​the opening 130 where the information is to be displayed when the protective layer 13 is disposed using a liquid ejection head.

[0071] In the module component 1-8, the sheet resistance of the conductive layer 12 can be measured by bringing an electrode into contact with the conductive layer 12 exposed from the protective layer 13 by the opening 130 that displays the information. Furthermore, in the module component 1-8, by providing information using a liquid ejection head, it is not necessary to make the protective layer thick enough to allow for removal processing, as compared to when information is provided by removing the surface of the protective layer using laser processing or the like, and therefore the module component 1-8 can be made low-profile.

[0072] (Evaluation results for discoloration and uneven color) In the module component 1-1 according to the comparative example, the color of the conductive layer was originally a light copper color, but after heating at 230°C for one minute, which is the same as solder reflow, the color changed to dark brown. In addition, in the module component 1-1 according to the comparative example, variations in the shade of brown and bluish color unevenness were visible in the area that had changed to dark brown.

[0073] On the top surface of each of module components 1-2 according to Example 1 to module components 1-8 according to Example 7, the color of Cu visible under the 10 μm solder resist layer that is protective layer 13 hardly changed, and no color unevenness was visible.

[0074] Although the protective layer 13 was not provided on the side surfaces of the module components 1 according to Examples 2 and 3, discoloration and color unevenness were not noticeable. Therefore, it is considered that the protective layer 13 does not necessarily have to be provided on the side surfaces of the module component 1. In particular, in the case of the module component 1-3 having a low profile with a thickness of 1 mm or less, discoloration and color unevenness on the side surface 1-3b are not noticeable, so it is considered that the protective layer 13 does not have to be provided.

[0075] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments of the present invention without departing from the scope of the claims.

[0076] All ordinal numbers, quantitative numbers, and other figures used in the description of the embodiments of the present invention are provided as examples to specifically explain the technology of the present invention, and the present invention is not limited to the illustrated figures. Furthermore, the connection relationships between components are provided as examples to specifically explain the technology of the present invention, and do not limit the connection relationships that realize the functions of the present invention.

[0077] The liquid ejection head according to the embodiment may be any functional component that ejects or sprays liquid from a nozzle. The energy source for ejecting the liquid may be a piezoelectric actuator, a thermal actuator using an electrothermal conversion element such as a heating resistor, or an electrostatic actuator consisting of a vibration plate and an opposing electrode. However, the ejection energy generating means used is not limited to these examples.

[0078] The manufacturing method for a module component according to an embodiment of the present invention can reduce discoloration of the conductive layer while ensuring electromagnetic wave shielding function, and therefore can be suitably used for manufacturing module components used in mobile devices such as smartphones, tablet terminals, and notebook PCs (Personal Computers), as well as PCs, home appliances, etc. However, the manufacturing method for a module component according to an embodiment of the present invention is not limited to the above applications, and can be used for manufacturing module components used in a variety of applications.

[0079] For example, aspects of the present invention are as follows. <1> A method for manufacturing a module component includes the steps of: arranging, on an electronic component, a conductive layer that is electrically connected to a ground wiring; arranging, on the conductive layer, a protective layer whose surface resistivity is three orders of magnitude higher than that of the conductive layer; measuring the sheet resistance of the conductive layer after arranging the protective layer; and determining that the electromagnetic shielding performance of the conductive layer is acceptable if the measured sheet resistance of the conductive layer is lower than a predetermined threshold value. <2> The protective layer has an opening, and a part of the conductive layer is exposed through the opening. <1> This is a method for manufacturing the module component described in the above. <3> In the step of measuring the sheet resistance of the conductive layer, the sheet resistance of the conductive layer is measured by an electrode that contacts a part of the conductive layer that is exposed through the opening in the protective layer. <2> This is a method for manufacturing the module component described in the above. <4> the protective layer is disposed on the entire upper surface of the conductive layer, and in the step of measuring the sheet resistance of the conductive layer, the sheet resistance of the conductive layer is measured by an electrode having a pointed shape that penetrates the protective layer and comes into contact with the conductive layer. <1> From the above <3> 1 is a method for manufacturing a module component according to any one of the above. <5> the protective layer is disposed on the entire upper surface of the conductive layer, and in the step of measuring the sheet resistance of the conductive layer, the sheet resistance of the conductive layer is measured by a monopole eddy current measuring device; <1> From the above <4> 1 is a method for manufacturing a module component according to any one of the above. <6> The monopole eddy current measuring instrument measures the sheet resistance of the conductive layer without contacting the protective layer. <5> This is a method for manufacturing the module component described in the above. <7> the protective layer is disposed on the entire upper surface of the conductive layer, and in the step of measuring the sheet resistance of the conductive layer, the sheet resistance of the conductive layer is measured based on a measurement value of at least one of a capacitance value and a resistance value including the protective layer using an LCR meter. <1> From the above <6> 1 is a method for manufacturing a module component according to any one of the above. <8> In the step of disposing the protective layer, the protective layer is disposed by liquid ejected from a liquid ejection head. <1> From the above <7> 1 is a method for manufacturing a module component according to any one of the above. <9> The module component includes an electronic component, a conductive layer disposed on the electronic component, and a protective layer disposed on the conductive layer, the protective layer having a surface resistivity three or more orders of magnitude higher than that of the conductive layer, the conductive layer being electrically connected to a ground wiring, and the protective layer having an opening that exposes a portion of the conductive layer. <10> information is provided by the opening provided in the protective layer; <9> It is a module component described in [Explanation of symbols]

[0080] 1 Module parts 11 Electronic Components 11a Top surface of electronic components 12 Conductive layer 12a Upper surface of conductive layer 13 Protective layer 130 Open area 14 Ground wiring 15 PCB 16 Sealing resin layer 20a~20d electrode 21 Unipolar eddy current measuring device 21X Bipolar Eddy Current Meter 211 Probe 212 Coil 30 LCR Meter 40 Copper foil 50 Resin Blocks Bh AC magnetic field Ip high frequency alternating current [Prior art documents] [Patent documents]

[0081] [Patent Document 1] Patent No. 6412844

Claims

1. disposing a conductive layer on the electronic component, the conductive layer being electrically connected to the ground wiring; disposing a protective layer on the conductive layer, the protective layer having a surface resistivity three or more orders of magnitude higher than the surface resistivity of the conductive layer; measuring the sheet resistance of the conductive layer after disposing the protective layer; and determining that the electromagnetic wave shielding performance of the conductive layer is acceptable if the measured value of the sheet resistance of the conductive layer is lower than a predetermined threshold value.

2. The protective layer has an opening, The method for manufacturing a module component according to claim 1 , wherein a portion of the conductive layer is exposed through the opening in the protective layer.

3. 3. The method for manufacturing a module component according to claim 2, wherein in the step of measuring the sheet resistance of the conductive layer, the sheet resistance of the conductive layer is measured by an electrode that contacts a portion of the conductive layer that is exposed through the opening in the protective layer.

4. the protective layer is disposed on the entire upper surface of the conductive layer; 2. The method for manufacturing a module component according to claim 1, wherein in the step of measuring the sheet resistance of the conductive layer, the sheet resistance of the conductive layer is measured using an electrode having a pointed shape that penetrates the protective layer and comes into contact with the conductive layer.

5. the protective layer is disposed on the entire upper surface of the conductive layer; 2. The method for manufacturing a module component according to claim 1, wherein in the step of measuring the sheet resistance of the conductive layer, the sheet resistance of the conductive layer is measured by a monopole eddy current measuring device.

6. The method for manufacturing a module component according to claim 5 , wherein the monopole eddy current measuring instrument measures the sheet resistance of the conductive layer without contacting the protective layer.

7. the protective layer is disposed on the entire upper surface of the conductive layer; 2. The method for manufacturing a module component according to claim 1, wherein in the step of measuring the sheet resistance of the conductive layer, the sheet resistance of the conductive layer is measured based on a measurement value of at least one of a capacitance value and a resistance value including the protective layer, using an LCR meter.

8. The method for manufacturing a module component according to claim 1 , wherein in the step of disposing the protective layer, the protective layer is disposed by liquid ejected from a liquid ejection head.

9. Electronic components and a conductive layer disposed on the electronic component; a protective layer disposed on the conductive layer and having a surface resistivity three or more orders of magnitude higher than that of the conductive layer; the conductive layer is electrically connected to a ground wiring, The protective layer has an opening that exposes a portion of the conductive layer.

10. The module component according to claim 9 , wherein information is provided by the opening provided in the protective layer.

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