Substrate for electronic component mounting, electronic device, electronic module, and method for manufacturing substrate for electronic component mounting

Abstract

An electronic component mounting substrate 1 includes: a first insulating layer and a second insulating layer; a first metal layer; and a through conductor. The first insulating layer and the second insulating layer are arranged in a first direction. The first metal layer is located between the first insulating layer and the second insulating layer. The through conductor extends in the first direction from the first insulating layer to the second insulating layer. The first metal layer has: a first portion separated from the through conductor; and a second portion connected to the through conductor. Furthermore, the thickness of the second portion is greater than the thickness of the first portion.

Description

Technical Field

[0001] This disclosure relates to electronic component mounting substrates, electronic devices, electronic modules, and methods for manufacturing electronic component mounting substrates. Background Technology

[0002] A known substrate for mounting electronic components includes an insulating layer and a wiring layer, and has a through conductor.

[0003] In recent years, electronic components have been demanding higher functionality, leading to an increasing trend in the number of terminals. Consequently, in electronic component mounting substrates, the number of connection points in wiring layers, such as within the same upper and lower layers, has increased, requiring high connection reliability. Regarding the vertical connections, i.e., through conductors, there are methods that involve stacking insulating layers containing through conductors. However, there are concerns that misalignment of the conductors in the insulating layers between upper and lower layers due to process errors could result in non-electrical connections or / or unexpected electrical connections. Furthermore, the inability to reduce the size of the conductors in each insulating layer or / and the distance between through conductors poses an obstacle to high-density wiring in electronic component mounting substrates.

[0004] In Patent Document 1, a method for manufacturing a substrate for mounting electronic components is described as follows: in order to improve the electrical connection between the through conductors of the upper and lower layers, a laminate including an insulating layer and a wiring layer is formed, and after forming a through hole with a laser, a through conductor is formed in the through hole (see Japanese Patent Application Publication No. 2017-183337).

[0005] One method for forming through-holes in a laminate of insulating layers involves forming the through-hole by punching with a pin using a die, and then fabricating a through conductor within the through-hole. During this punching process, the wiring layer (internal wiring) that facilitates the electrical connection with the through conductor may sometimes deform due to the pin's pressure. This deformation raises concerns that the contact area between the through conductor and the internal wiring may decrease, leading to increased resistance and hindering the high functionality of electronic devices. Therefore, a high reliability connection between the through conductor and the internal wiring is desired for the electronic component mounting substrate. Summary of the Invention

[0006] One aspect of this disclosure relates to an electronic component mounting substrate comprising a first insulating layer and a second insulating layer, a first metal layer, and a through conductor. The first insulating layer and the second insulating layer are arranged in a first direction. The first metal layer is located between the first insulating layer and the second insulating layer. The through conductor extends in the first direction from the first insulating layer to the second insulating layer. The first metal layer has: a first portion separately disposed from the through conductor; and a second portion connected to the through conductor. Furthermore, the thickness of the second portion is greater than the thickness of the first portion.

[0007] The electronic device according to one aspect of this disclosure includes: the aforementioned electronic component mounting substrate; and electronic components mounted on the electronic component mounting substrate.

[0008] One aspect of this disclosure relates to an electronic module comprising: the aforementioned electronic device; and a housing covering the electronic device on which it is mounted.

[0009] The method for manufacturing an electronic component mounting substrate according to one aspect of this disclosure includes five steps. In the first step, a first insulating layer and a second insulating layer are prepared. In the second step, a first metal layer with a different thickness is disposed on the second insulating layer. In the third step, the first insulating layer is stacked with the first metal layer sandwiched between them to obtain a first laminate. In the fourth step, a through-hole is formed penetrating the first laminate, such that it penetrates the thicker portion of the first metal layer in the stacking direction. In the fifth step, a through conductor is formed within the through-hole.

[0010] One aspect of the present disclosure relates to a method for manufacturing an electronic component mounting substrate, comprising steps A to E. In step A, metal layer A, metal layer B, a first insulating layer, and a second insulating layer are prepared. In step B, metal layer A and metal layer B are disposed between the first insulating layer and the second insulating layer, such that at least a portion of them overlap. In step C, the first insulating layer, metal layer A, metal layer B, and the second insulating layer are sequentially stacked to obtain a second laminate. In step D, a through-hole is formed through the second laminate, extending through the overlapping portion of metal layer A and metal layer B in the stacking direction. Then, in step E, a through conductor is formed within the through-hole. Attached Figure Description

[0011] Figure 1 (a) is a top view of the electronic component mounting substrate and electronic device according to the first embodiment of this disclosure. Figure 1 (b) is with Figure 1 The cross-sectional view corresponding to line X1-X1 in (a).

[0012] Figure 2 (a) is a top view of an electronic module according to another embodiment of the first embodiment of this disclosure. Figure 2 (b) is with Figure 2 The cross-sectional view corresponding to the X2-X2 line in (a).

[0013] Figure 3 yes Figure 1 An enlarged view of the main part A in (b).

[0014] Figure 4 It is equivalent to Figure 1 The location of the main part A Figure 2 An enlarged view of the structure shown.

[0015] Figure 5 It is equivalent to Figure 1 Enlarged view of the other ways involving the location of the main part A.

[0016] Figure 6 This is a schematic diagram illustrating a method for manufacturing an electronic component mounting substrate according to the first embodiment of this disclosure.

[0017] Figure 7 This is a schematic diagram illustrating a method for manufacturing an electronic component mounting substrate according to the first embodiment of this disclosure.

[0018] Figure 8 This is a schematic diagram illustrating another aspect of the manufacturing method of the electronic component mounting substrate according to the first embodiment of this disclosure.

[0019] Figure 9 This is a schematic diagram illustrating another aspect of the manufacturing method of the electronic component mounting substrate according to the first embodiment of this disclosure.

[0020] Figure 10 (a) is a schematic view of the periphery of a through conductor in a substrate for mounting electronic components according to the second embodiment of this disclosure, viewed in the first direction. Figure 10 (b) is with Figure 10 The cross-sectional view corresponding to the X10-X10 line in (a).

[0021] Figure 11 (a) is a schematic view of the periphery of a through conductor in a substrate for mounting electronic components according to the third embodiment of this disclosure, viewed in the first direction. Figure 11 (b) is with Figure 11 The cross-sectional view corresponding to the X11-X11 line in (a).

[0022] Figure 12 It is equivalent to Figure 1 A cross-sectional view of the electronic component mounting substrate according to the fourth embodiment of this disclosure at the location of the main part A.

[0023] Figure 13 It is equivalent to Figure 1 A cross-sectional view of the electronic component mounting substrate according to the fifth embodiment of this disclosure at the location of the main part A.

[0024] Figure 14 It is equivalent to Figure 1 A cross-sectional view of the electronic component mounting substrate according to the sixth embodiment of this disclosure at the location of the main part A.

[0025] Figure 15 (a) is a schematic view obtained from the first direction of viewing the periphery of the through conductor in the electronic component mounting substrate according to the first embodiment of this disclosure. Figure 15 (b) is with Figure 15 The cross-sectional view corresponding to line X15-X15 in (a). Detailed Implementation

[0026] <Structure of electronic component mounting substrate and electronic device>

[0027] Several exemplary embodiments of this disclosure will be described below with reference to the accompanying drawings. In the following description, a structure in which electronic components are mounted on an electronic component mounting substrate is defined as an electronic device. A structure having a housing covering the electronic device mounted on the electronic component mounting substrate is defined as an electronic module. The electronic component mounting substrate, electronic device, and electronic module can be oriented either upwards or downwards, but for convenience, an orthogonal coordinate system xyz is defined, and the positive side of the z-direction is defined as upwards. Furthermore, the direction from upwards to downwards is defined as the first direction.

[0028] (First Embodiment)

[0029] refer to Figures 1-9 This invention will describe the electronic component mounting substrate and the electronic device equipped with it according to the first embodiment of this disclosure. Figure 1 The image shows a top view and a cross-sectional view of the electronic device 21. Figure 2 This shows a top view and a cross-sectional view of the electronic module 31. Additionally, in... Figures 3-5 Show Figure 1 The main part A, and equivalent to Figure 1 An example of an enlarged view showing the location of the main part A in the image. Additionally, in... Figures 6-9 A schematic diagram of the manufacturing method of substrate 1 for mounting electronic components is shown.

[0030] The electronic component mounting substrate 1 has a mounting area 4 for mounting electronic components 10 on its upper surface. The electronic component mounting substrate 1 has at least a first insulating layer 2a and a second insulating layer 2b positioned in a first direction. Furthermore, a first metal layer 6 serving as internal wiring is provided between the first insulating layer 2a and the second insulating layer 2b. Furthermore, a through conductor 5 extending in the first direction from the first insulating layer 2a to the second insulating layer 2b is provided. Additionally, in… Figure 1 In the middle, the through conductor 5 penetrates the 5 layers of insulation.

[0031] Furthermore, the first metal layer 6 has a first part 6a and a second part 6b connected to the through conductor 5, the second part 6b being thicker than the first part 6a.

[0032] Here, "thickness" refers to the dimension in the first direction. In other words, "thickness" refers to the dimension in the stacking direction. Furthermore, "mounting area 4" is the area where at least one electronic component 10 is mounted, and can be suitable for example, defined as the inner side of the outermost periphery of the electrode pad 3 described later, or the area within it. Moreover, the electronic component 10 mounted in mounting area 4 is not limited to electronic components; for example, it can also be an electronic part. Furthermore, the number of electronic components 10 mounted is not limited.

[0033] The electronic component mounting substrate 1 has multiple insulating layers, such as a first insulating layer 2a and a second insulating layer 2b. Hereinafter, when multiple insulating layers are considered, they will be referred to as insulating layer 2.

[0034] Examples of electrically insulating ceramics used as materials for insulating layer 2 include alumina sintered bodies, mullite sintered bodies, silicon carbide sintered bodies, aluminum nitride sintered bodies, silicon nitride sintered bodies, and glass-ceramic sintered bodies. Alternatively, resins can be used as materials for insulating layer 2, such as thermoplastic resins, epoxy resins, polyimide resins, acrylic resins, phenolic resins, or fluorinated resins.

[0035] Multiple insulating layers 2, at least two layers are required, such as Figure 1 As shown, it can be formed from 5 layers, or from 4 or fewer layers, or 6 or more layers. With the same thickness, the electronic component mounting substrate 1 can be made thinner by reducing the number of insulating layer 2 layers. Furthermore, with the same thickness, increasing the number of insulating layer 2 layers can improve the rigidity of the electronic component mounting substrate 1.

[0036] The electronic component mounting substrate 1 may have an outermost side with a size of 0.3 mm to 10 cm. When viewed from above, the electronic component mounting substrate 1 may be quadrilateral, but it can also be square or rectangular. In addition, the electronic component mounting substrate 1 may have a thickness of 0.2 mm or more.

[0037] External circuit connection electrodes can be provided on the upper, side, or lower surface of the electronic component mounting substrate 1. The external circuit connection electrodes electrically connect the electronic component mounting substrate 1 and the external circuit board.

[0038] Furthermore, in the electronic component mounting substrate 1, in addition to the first metal layer 6 formed between the insulating layers 2, the through conductor 5, the electrode pads 3, and the external circuit connection electrodes, there are also electrodes that serve as other metal layers, wiring conductors, and through conductors other than the through conductor 5 that connect the wiring conductors vertically to each other. These electrodes, wiring conductors, and wiring other than the through conductor 5 may be located only on the surface of the electronic component mounting substrate 1, or only inside, or both on the surface and inside.

[0039] When the insulating layer 2 is made of electrically insulating ceramic, the materials used for the first metal layer 6, the through conductor 5, the electrode pads 3, the electrodes for external circuit connections, and other metal layers can include tungsten (W), molybdenum (Mo), manganese (Mn), palladium (Pd), silver (Ag), or copper (Cu), or alloys containing at least one of these metal materials. Furthermore, when the insulating layer 2 is made of resin, the materials used for the first metal layer 6, the through conductor 5, the electrode pads 3, the electrodes for external circuit connections, and other metal layers can include copper (Cu), gold (Au), aluminum (Al), nickel (Ni), molybdenum (Mo), palladium (Pd), or titanium (Ti), or alloys containing at least one of these metal materials.

[0040] The first metal layer 6, the through conductor 5, the electrode pads 3, the electrodes for external circuit connections, and other metal layers may further have plating layers on the exposed portions of each upper surface or insulating layer 2. According to this structure, since the exposed portions of each upper surface or insulating layer 2 are protected, oxidation can be reduced. Furthermore, according to this structure, the electrode pads 3 and electronic components 10 can be electrically connected effectively via electronic component connection members 13 such as wire bonding. For example, a Ni plating layer with a thickness of 0.5 μm to 10 μm may be applied, or the Ni plating layer and a gold (Au) plating layer with a thickness of 0.5 μm to 3 μm may be applied sequentially.

[0041] like Figure 3 As shown, the first metal layer 6 has a first part 6a and a second part 6b connected to the through conductor 5. The thickness of the second part 6b is greater than the thickness of the first part 6a. The first part 6a is separated from the through conductor 5. Here, the first part 6a and the second part 6b are distinguished by their thickness, and their materials can be the same or different. Furthermore, the thickness, if determined by… Figure 3 The cross-section shown along the first direction refers to the length in the vertical direction. Here, the second part 6b of the first metal layer 6 is provided to improve the connection reliability between the through conductor 5 that passes through the multiple insulating layers 2 and the metal layer located between the multiple insulating layers 2.

[0042] Since the thickness of the second part 6b, which is connected to the through conductor 5, is greater than the thickness of the first part 6a, the contact area between the second part 6b and the through conductor 5 is larger, thus reducing the obstacles to the high functionality of electronic devices caused by the increased resistance.

[0043] Furthermore, when the thickness of the second part 6b is greater than the thickness of the first part 6a, whenever a through hole for forming the through conductor 5 is formed, if the through conductor 5 is formed after the through hole is formed in the interior including the second part 6b, even if the device is deformed due to the pressing of the pin, the high resistance caused by the large contact area between the second part 6b and the through conductor 5 will result in fewer obstacles to the high functionality of the electronic device.

[0044] Here, the first metal layer 6 having the first part 6a and the second part 6b can be located between multiple insulating layers 2, or it can be a single layer only between the first insulating layer 2a and the second insulating layer 2b. In this case, the first metal layer 6 located outside the space between the first insulating layer 2a and the second insulating layer 2b can also be another metal layer 6c. Furthermore, the second part 6b can be provided at multiple locations between the insulating layers 2, or it can be provided at only one location. In addition, when the second part 6b is provided at multiple locations, the thickness of the second part 6b as viewed in cross-section can be different for each location.

[0045] exist Figures 3-6 An example showing an enlarged view of the main part A (or the part equivalent to the main part A) of this embodiment.

[0046] exist Figure 3 In the example shown, part 6b is one layer thicker than part 6a. In other words, part 6b is a single coating or printing and is thicker than part 6a. Furthermore, in... Figure 4 In the example shown, the second part 6b has a total thickness of at least two layers and is thicker than the first part 6a. This embodiment achieves its intended effect in both cases.

[0047] like Figure 3 As shown in the example, since the second part 6b is coated or printed in one step and is thicker than the first part 6a, there are fewer process errors in the process of coating or printing the paste to form the first metal layer 6. Therefore, the clearance between the second part 6b and the first part 6a can be ensured with good accuracy, and when the electronic component mounting substrate 1 is wired with high density, there are fewer accidental short circuits between the wirings of different signals.

[0048] like Figure 4 As shown in the example, the second part 6b has a combined thickness of two layers and is thicker than the first part 6a. In other words, the paste that will become the first metal layer 6 is applied or printed twice. Therefore, for example, when the portion with the same thickness as the first part 6a is designated as the first layer 6b1 and the portion located on the first layer is designated as the second layer 6b2, it is possible to appropriately add metal components or the like to the paste that becomes the second layer 6b2 to improve its properties, or to change its viscosity. As a property improvement, for example, the electrical properties can be improved by adding a low-resistance material such as copper. In addition, by using a low-viscosity material, deformation of the second part 6b during pin insertion can be suppressed.

[0049] Furthermore, the first metal layer 6 may have a first clearance portion 7 between the second portion 6b and the first portion 6a. That is, the second portion 6b can be located separately from the first portion 6a through the first clearance portion 7. When such a structure is satisfied, for example, since the first portion 6a can be used as a wiring layer for signals flowing through a different conductor 5, it contributes to high-density wiring.

[0050] In addition, such as Figure 1 As shown, the system includes a third insulating layer 2c arranged in the first direction with the second insulating layer 2b; and a second metal layer 9 located between the second insulating layer 2b and the third insulating layer 2c. In this case, a second gap 8 may also be provided between the through conductor 5 and the second metal layer 9. That is, the through conductor 5 can be separated from the second metal layer 9 through the second gap 8. With this structure, the second metal layer 9 can be used as a wiring layer for signals flowing through the through conductor 5 and the first part 6a, thus contributing to high-density wiring. Furthermore, if the high-density wiring of the electronic component mounting substrate 1 can be further improved, the electronic device 21 can achieve high functionality and miniaturization. Additionally, the second metal layer 9 does not necessarily have to be a wiring layer for signals flowing through the first part 6a; it can also be connected to other through conductors to be used as a wiring layer for the same signals.

[0051] It can also be like Figure 5 As shown in the example, the second part 6b is located within the second clearance part 8 in the top perspective view in the first direction. Figure 5 The example shown illustrates an overlap between the outer edge of the second part 6b and the inner edge of the second clearance part 8. This includes cases where the second part 6b overlaps with the inner edge of the second clearance part 8. With this structure, since the thickness of the second part 6b is reduced by the amount of thickness being greater than that of the first part 6a through the lamination, the bulging of the surface around the through conductor 5 in the electronic component mounting substrate 1 can be reduced.

[0052] In other words, by having the second clearance portion 8, the depression generated on the surface around the through conductor 5 in the electronic component mounting substrate 1 can be reduced.

[0053] Furthermore, the second clearance portion 8 can be located within the second portion 6b in a top view in the first direction. With such a structure, the bulging and depression of the surface can be reduced in the portion close to the through conductor 5, and high-density wiring can be performed.

[0054] <Structure of Electronic Devices>

[0055] exist Figure 1An example of electronic device 21 is shown. Electronic device 21 includes an electronic component mounting substrate 1 and electronic components 10 mounted on the upper surface of the electronic component mounting substrate 1.

[0056] Examples of electronic components 10 include, for instance, camera elements such as CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor), light-emitting elements such as LED (Light Emitting Diode), and components or integrated circuits that have sensor functions such as pressure, air pressure, acceleration, or gyroscope.

[0057] Alternatively, the electronic component 10 can be disposed on the upper surface of the electronic component mounting substrate 1 using an adhesive material. Examples of such adhesive materials include silver epoxy resin or thermosetting resin. Furthermore, the electronic component 10 and the electronic component mounting substrate 1 can be electrically connected, for example, using an electronic component connecting member 13.

[0058] The electronic device 21 may have a cover 12 that covers the electronic component 10 and is engaged with the upper surface of the electronic component mounting substrate 1.

[0059] For example, if the electronic component 10 is a camera element such as CMOS or CCD, or a light-emitting element such as LED, the cover 12 can be made of a highly transparent material such as glass. Alternatively, if the electronic component 10 is an integrated circuit, the cover 12 can be made of a metallic material, a ceramic material, or an organic material.

[0060] The cover 12 can also be joined to the electronic component mounting substrate 1 by means of the cover connecting member 14. As a material constituting the cover connecting member 14, examples include solder made of thermosetting resin, low melting point glass or metal components.

[0061] Because the electronic device 21 has the electronic component mounting substrate 1 of this disclosure, it has excellent reliability and can maintain the characteristics of the electronic component 10 for a long time. In addition, by arranging the first clearance portion 7, the second clearance portion 8 and the second metal layer 9 in the electronic component mounting substrate 1, the wiring density can be increased, thereby enabling high functionality and miniaturization of the electronic device 21.

[0062] <Structure of Electronic Module>

[0063] exist Figure 2An example of an electronic module 31 is shown. The electronic module 31 includes a housing 32 that covers the electronic components 10 housed in the electronic device 21. The housing 32 improves airtightness and reduces external stress on the electronic device 21. The housing 32 is made of, for example, resin or metal. Figure 2 The image shows an example where the electronic component 10 is covered by the cover connecting member 14 and the cover 12, and then by the outer casing 32. Additionally, in... Figure 2 In the example shown, the housing 32 also covers the side of the electronic component mounting substrate 1, but the electronic component 10 may also be covered on the upper surface of the electronic component mounting substrate 1.

[0064] The housing 32 may also have a lens in part. Here, not only one lens can be installed, but multiple lenses can be installed, and the material can be resin, glass, or crystal, etc. In addition, the housing 32 may also have a drive device for up-down and left-right movement, which is electrically connected to the pads on the surface of the electronic component mounting substrate 1 via solder or other bonding materials. This type of electronic module 31 is called a camera module.

[0065] Additionally, the housing 32 may have an opening for inserting an external circuit board. Here, when the housing 32 has an opening and an external circuit board is inserted, after being electrically connected to the electronic component mounting substrate 1, the gap of the opening may be sealed with a sealing material such as resin to achieve airtightness inside the housing 32.

[0066] <Method for Manufacturing Electronic Component Mounting Substrates and Electronic Devices>

[0067] Next, an example of a manufacturing method for the electronic component mounting substrate 1 and the electronic device 21 of this embodiment will be described. Furthermore, the manufacturing method described below is an example of a manufacturing method for a multi-piece assembly.

[0068] use Figure 6 as well as Figure 7 The following steps will be explained.

[0069] The manufacturing method of the electronic component mounting substrate 1 includes: a first step of preparing a first insulating layer and a second insulating layer; a second step of disposing a first metal layer with a different thickness on the second insulating layer; a third step of stacking the first insulating layer with the first metal layer sandwiched between them to obtain a first laminate 47; a fourth step of forming a through hole penetrating the first laminate 47 in the stacking direction to allow passage of the thicker portion of the first metal layer; and a fifth step of forming a through conductor within the through hole. Additionally, as described later... Figure 8 as well as Figure 9Therefore, the manufacturing method of the electronic component mounting substrate with different first and second metal paste layers, i.e., steps A to E, is basically the same as steps 1 to 5 described above. Steps 1 to 5 and steps A to E will be described in detail below as before firing, but it is also possible to prepare a first metal layer, a first insulating layer, and a second insulating layer, sinter them separately, and then assemble them together to manufacture the substrate.

[0070] Furthermore, in the following examples illustrating how the first metal layer, the first insulating layer, and the second insulating layer are formed through firing, therefore... Figure 6 as well as Figure 7 In the example shown, the paste that will become the first metal layer is collectively referred to as paste 46, the portion that will become part 1 is referred to as part 46a, and the portion that will become part 2 is referred to as part 46b. Similarly, the green sheet that will become the insulating layer is collectively referred to as green sheet 42, the green sheet that will become the first insulating layer is referred to as green sheet 42a, and the green sheet that will become the second insulating layer is referred to as green sheet 42b. Furthermore, metal layers A and B can be metal paste, or metal layers formed as solder pads or after sintering, etc.

[0071] Step 1: First, prepare green sheet 42, which includes green sheet 42a and green sheet 42b. Here, if the insulating layer is an alumina (Al2O3) sintered body, add sintering aid powders such as silicon dioxide (SiO2), magnesium oxide (MgO), and calcium oxide (CaO) to the Al2O3 powder, and then add appropriate binders, solvents, and plasticizers and mix to form a slurry. Afterwards, obtain a sheet-shaped shaped body by forming methods such as the doctor blade method or the burnishing roller method.

[0072] Next, the aforementioned sheet-like molded body is processed into its external shape using a mold or the like to obtain a green sheet 42. Figure 6 (a)). In this case, as an external shape, a slot, a through hole, or a slit for multiple pieces can be formed.

[0073] Furthermore, as another example, when the insulating layer is made of resin, a sheet-like insulating layer can be obtained by molding using a transfer molding method, injection molding, or pressing with a mold. As yet another example, when the insulating layer is glass epoxy resin, a substrate made of glass fiber is impregnated with the resin and thermocured at a given temperature, thereby obtaining a sheet-like insulating layer.

[0074] Step 2: Next, by using a screen printing method or similar technique, the first paste 46 is applied to the second green sheet 42b to arrange the first part 46a and the second part 46b, which has a thickness greater than that of the first part 46a, in a given position. Figure 6(b) Here, to obtain part 46b, it is coated to a given thickness (the thickness of part 46a) using a first screen, and then coated at a given position in the first coating area using a second screen, thereby obtaining the desired result. The first paste 46 is made by adding a suitable solvent and binder to a metal powder composed of the aforementioned metallic material and mixing it, thereby adjusting the viscosity to a suitable level. Alternatively, the first paste 46 may also contain glass or ceramic to improve the bonding strength with other laminated green sheets 42.

[0075] Alternatively, metal paste, which serves as a second metal layer, electrode pads, or electrodes for external circuit connections, can also be applied to other green wafers 42. When the green wafer 42 has through holes, metal paste can also be filled into these through holes.

[0076] Furthermore, as another example, when the insulating layer is made of resin, a first metal layer with varying thickness can be formed using methods such as sputtering or vapor deposition. Alternatively, a metal film can be deposited on the surface and then formed using a plating method.

[0077] Step 3: Next, the first green sheet 42a is laminated onto the second green sheet 42b, which is coated with a first paste 46 containing the first part 46a and a second part 46b with a thickness greater than that of the first part 46a, thereby obtaining the first laminate 47. Figure 7 (a)). Furthermore, this description focuses on a two-layer stack, but according to... Figure 6 In the example shown, the first layer 47 can be made by stacking five green sheets 42. Alternatively, after obtaining the first layer 47, a notch or recess can be made using a mold or the like.

[0078] Step 4: Next, a mold is used to form a through hole, including part 2 46b penetrating the first laminate 47, so that it penetrates the thicker portion of the first metal layer in the lamination direction (first direction). Besides molds, other methods for forming the through hole include punching and laser cutting.

[0079] Step 5: Next, the through conductor 45 is formed by filling the through hole formed in step 4 with the aforementioned metal paste. Figure 7 (b) indicates that a through conductor 45 is formed in the first layer 47.

[0080] Next, at a given position on the first laminate 47 having the through conductor 45, a dividing groove is formed using a mold, punch, slicing device, or laser. Alternatively, the dividing groove can also be formed after firing using a slicing device.

[0081] Next, a sintered body is obtained by firing the first laminate 47 having the through conductor 45 at a temperature of approximately 1500°C to 1800°C. Furthermore, through this process, the aforementioned first paste 46 and green sheet 42 are simultaneously fired to form the first metal layer. The same applies to the through conductor, the second metal layer, the electrode pads, and the electrodes for external circuit connections.

[0082] Next, by dividing the obtained sintered body into individual pieces, a substrate for mounting electronic components can be obtained. This division is performed by breaking along previously formed dividing grooves. Alternatively, dividing grooves can be omitted, and a slicing device can be used to divide the sintered body. Furthermore, electrolytic or electroless plating methods can be used before or after division to coat the surfaces of the electrode pads, external connection pads, and the metal layers exposed at the time point of the sintered body.

[0083] Next, an electronic device is obtained by mounting electronic components onto the obtained electronic component mounting substrate. The electronic components are electrically bonded to the electronic component mounting substrate using electronic component connecting members. Alternatively, the electronic components can be fixed to the electronic component mounting substrate using adhesive materials or the like.

[0084] Furthermore, in the obtained electronic device, an electronic module can be obtained by having a casing covering the electronic components.

[0085] In addition, Part 2, 46b can also be like Figure 8 As shown in the example, the first layer of metal paste and the second layer of metal paste are formed differently.

[0086] In addition, it can also be like Figure 9 As shown in the example, metal paste is applied to given positions on the first green sheet 42a, which becomes the first insulating layer, and the second green sheet 42b, which becomes the second insulating layer, and then they are stacked to obtain the second part 46b. According to this method, when metal paste is printed multiple times on the same side, the printing area of ​​the second layer becomes the first layer of metal paste. In contrast, since the printing area is on the green sheet 42, the adhesion of metal paste to the screen and the possibility of a decrease in printing accuracy due to adhesion are less, and the printing itself is easier.

[0087] (Second Implementation)

[0088] The first metal layer 6 is sometimes a signal line, for example. Generally, the signal line differs from the potential pattern of the power supply and ground, and is connected to other wiring by a through conductor 5. Therefore, the through conductor 5 and the signal line require higher reliability of the electrical connection. In this regard, by constructing the signal line (first metal layer 6) with a second part 6b as in this embodiment, the reliability of the electrical connection can be improved.

[0089] exist Figure 10 An example of a signal line is shown. Figure 10 The following example is shown: In a top view in the first direction, the first part 6a is larger in both the x and y directions than the second part 6b which is connected to the through conductor 5, and extends to the negative side of the x direction.

[0090] (Third Implementation)

[0091] exist Figure 11 Other examples of signal lines are shown. Figure 11 The following example is shown: the first part 6a is smaller in the y direction than the second part 6b, which is located at the position connected to the through conductor 5. If the second part 6b is taken as a reference, it extends from the second part 6b to the negative side in the x direction.

[0092] Alternatively, it can be like Figure 11 As shown in example (b), the second layer 6b2 is configured to be in contact with the underlying insulating layer 2. In achieving this structure, the second part 6b becomes inclined. Figure 11 In (b), compared with when the edge is erected on the upper part of the second part 6b, the stress involved in the insulating layer 2 corresponding to the edge is reduced, and the reliability of the mechanical properties is excellent.

[0093] (Fourth implementation)

[0094] like Figure 12 As shown, the first insulating layer 2a may also have a region sandwiched between the first metal layer 6 and the through conductor 5 in a direction orthogonal to the first direction. With such a structure, when heat is generated or transferred in the through conductor 5 and the first metal layer 6, the expansion of the through conductor 5 and the first metal layer 6 can be suppressed.

[0095] (Fifth Embodiment)

[0096] Next, refer to Figure 13 To illustrate other examples in Part 2, 6b.

[0097] It can also be like Figure 13 As shown in the example, the second part 6b increases in thickness towards the through conductor 5. With this structure, the connection reliability between the through conductor 5 and the first metal layer 6 containing the second part 6b is excellent. Furthermore, with this structure, because it has an upwardly sloping portion towards the through conductor 5, the stress applied to the corners of the insulating layer 2, which is connected to both the through conductor 5 and the second part 6b respectively, is less than when the insulating layer 2 has sharp edges, resulting in excellent mechanical property reliability.

[0098] As manufacturing Figure 13The method for mounting electronic components on substrate 1 shown, for example, involves creating a laminate of green sheets by coating metal paste to form parts 6a and 6b, and in the process of providing through holes in the parts that form through conductors 5, for example, by slowing down the speed at which the pin is retracted after being pressed into the mold, the second layer 6b1 is made to follow the pin, thereby enabling the fabrication of... Figure 13 The shape shown.

[0099] (Sixth Embodiment)

[0100] Next, refer to Figure 14 To illustrate other examples in Part 2, 6b.

[0101] like Figure 14 As shown in the example, the second part 6b has: a first region R1 connected to the through conductor 5; and a second region R2 arranged in a direction orthogonal to the first direction and disposed further away from the through conductor 5 than the first region R1. The thickness of the second region R2 can be smaller than the thickness of the first region R1. That is, the second part 6b can have a smaller thickness in the portion away from the through conductor 5 in the direction orthogonal to the first direction. When such a structure is satisfied, the possibility of gaps being generated in the portion further away from the through conductor 5 in the direction orthogonal to the first direction compared to the second part 6b can be reduced. The same applies to the first part 6a.

[0102] Furthermore, as an example of a portion of the second part 6b that is far from the through conductor 5 in a direction orthogonal to the first direction having a small thickness, the cross-sectional shape can be a lens shape. Here, a lens shape refers to a shape in which the thickness of the second part 6b decreases curvilinearly as it moves toward the portion of the second part 6b that is far from the through conductor 5 in a direction orthogonal to the first direction.

[0103] In this way, when part 2, 6b, is in the shape of a lens, the possibility of gaps being generated can be further reduced.

[0104] Furthermore, this disclosure is not limited to the examples of the embodiments described above, and various modifications, such as numerical variations, are possible. Additionally, for example, in the examples shown in the figures, the shape of the electrode pads 3 is rectangular when viewed from above, but it could also be circular or other polygonal shapes. Furthermore, the arrangement, number, shape, and mounting method of the electronic components of the electrode pads 3 in this embodiment are not specified. Furthermore, the various combinations of feature portions in this embodiment are not limited to the examples of the embodiments described above. Moreover, combinations of the various embodiments are also possible.

[0105] Explanation of reference numerals in the attached figures

[0106] 1. Electronic component mounting substrate

[0107] 2···· Insulation layer

[0108] 2a···First Insulation Layer

[0109] 2b···Second Insulation Layer

[0110] 2c···Third Insulation Layer

[0111] 3····Electrode pads

[0112] 4···· Installation Area

[0113] 5····Penetrating conductor

[0114] 6····First Metal Layer

[0115] 6a···Part 1

[0116] 6b···Part 2

[0117] 6b1···First Floor

[0118] 6b2···Second Floor

[0119] 6c····Other metal layers

[0120] 7····The first clearance part

[0121] 8····Second Clearance Section

[0122] 9····Second Metal Layer

[0123] 10. Electronic Components

[0124] 12··· Cover

[0125] 13··· Electronic component connection components

[0126] 14··· Cover connecting components

[0127] 21. Electronic Devices

[0128] 31···Electronic Module

[0129] 32···Outer shell

[0130] 42··· Raw film

[0131] 42a··First raw film

[0132] 42b··Second raw film

[0133] 45···Penetrating conductor

[0134] 46···Metallic layer (metallic paste)

[0135] 46a··Part 1

[0136] 46b··Part 2

[0137] 47···First layer of stacked body

[0138] 48···Second layer of stacked body

[0139] R1··· Area 1

[0140] R2···Second District

Claims

1. A substrate for mounting electronic components, characterized in that, having: a first insulating layer; a second insulating layer located below the first insulating layer in a first direction; a through conductor extending in the first direction from the first insulating layer to the second insulating layer; a metal layer located above the first insulating layer and having a first portion provided separately from the through conductor, and a second portion in contact with the through conductor; and a first metal layer located between the first insulating layer and the second insulating layer and having a third portion in contact with the through conductor, and a fourth portion provided separately from the third portion by a first gap portion, the second portion having a thickness greater than that of the first portion.

2. The substrate for mounting electronic components according to claim 1, wherein the first portion is located above the first gap portion in the first direction.

3. The substrate for mounting electronic components according to claim 1, further comprising: a third insulating layer located below the second insulating layer in the first direction, the through conductor extending in the first direction from the first insulating layer to the third insulating layer.

4. The substrate for mounting electronic components according to claim 3, further comprising: a second metal layer located between the second insulating layer and the third insulating layer, the second metal layer having a fifth portion in contact with the through conductor, and a sixth portion provided separately from the fifth portion by a second gap portion.

5. The substrate for mounting electronic components according to claim 4, wherein the first gap portion is located above the second gap portion in the first direction.

6. The substrate for mounting electronic components according to claim 5, wherein the first portion is located above the first gap portion in the first direction.

7. The substrate for mounting electronic components according to claim 1, further comprising: an insulating layer, the insulating layer being located above the first insulating layer in the first direction.

8. The substrate for mounting electronic components according to claim 1, wherein the first insulating layer has a region sandwiched by the first metal layer and the through conductor in a direction orthogonal to the first direction.

9. The substrate for mounting electronic components according to claim 1, further comprising: an electrode pad electrically connected to the through conductor. comprising: the substrate for mounting electronic components according to claim 1; and an electronic component mounted on the substrate for mounting electronic components.

10. An electronic device, comprising: ​ ​ ​

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