Electronic component mounting substrate and manufacturing method thereof

Abstract

To provide an electronic component equipped substrate which can reduce the number of manufacturing steps and also can be thinner, and a method for manufacturing the electronic component equipped substrate.SOLUTION: The present invention includes: a substrate 10 having a first surface 11 on a first side and a second surface 12 on a second side opposite the first side and being provided with a through-hole 13 penetrating from the first surface 11 through the second surface 12; a penetration electrode 20 located in the through-hole 13 and partially protruding toward the second side with respect to the second surface 12, the penetration electrode at least partially including solder; and an electronic component 30 on the first surface 11, the electronic component being electrically connected to the penetration electrode 20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an electronic component mounting substrate and a method for manufacturing the same. [Background technology]

[0002] Various technologies related to electronic component mounting substrates on which electronic components are mounted have been proposed. For example, Patent Document 1 discloses a technology for connecting a wiring substrate and an IC chip using an interposer. In the technology described in Patent Document 1, an IC chip arranged on the upper surface side and a wiring substrate arranged on the lower surface side are electrically connected by an interposer having a glass substrate and filled via conductors that penetrate from the upper surface to the lower surface of the glass substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-139963 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology described in Patent Document 1 has a problem in that it is difficult to reduce the thickness of the interposer because the thickness of the glass substrate is the same as the thickness of the filled via conductor. Also, the technology described in Patent Document 1 requires that a solder bump separate from the filled via conductor be provided at the bottom end of the filled via conductor via a substrate connection terminal in order to electrically connect the filled via conductor to the wiring board. Therefore, the technology described in Patent Document 1 also has a problem in that it is difficult to reduce the number of manufacturing steps.

[0005] The present disclosure has been made in consideration of the above points, and aims to provide an electronic component mounting substrate that can reduce thickness and manufacturing steps, and a method for manufacturing the same. [Means for solving the problem]

[0006] In order to solve the above problems, in one aspect of the present disclosure, a substrate having a first surface on a first side and a second surface on a second side opposite to the first side, the substrate having a through hole extending from the first surface to the second surface; a through electrode located inside the through hole, partially protruding beyond the second surface toward the second side, and at least partially containing solder; and an electronic component located on the first surface and electrically connected to the through electrode.

[0007] The through electrode may contain solder powder.

[0008] The through electrode is partially containing the solder, a first conductive layer located on a side wall of the through hole and partially protruding beyond the second surface toward the second side; a second conductive layer located on the first conductive layer and containing the solder.

[0009] The through electrode may further include a third conductive layer located on the second conductive layer.

[0010] the electronic component has an electrode exposed on the first side; The electronic component mounting substrate is an insulating layer having insulating properties and located on the first surface, the through electrode, and the electronic component; The electronic component may further include a conductive layer that is partially located on the insulating layer and electrically connected to the through electrode and the electrode of the electronic component.

[0011] The conductive layer is a first portion located on the insulating layer; a second portion that penetrates the insulating layer from the first portion to the through electrode; and a third portion that penetrates the insulating layer from the first portion to the electrode of the electronic component.

[0012] The substrate may comprise glass.

[0013] In another aspect of the present disclosure, providing a substrate having a first surface on a first side and a second surface on a second side opposite the first side; forming a recess in the substrate from the first surface toward the second side; forming an electrode at least partially containing solder within the recess; mounting an electronic component on the first surface and electrically connecting the electronic component to the electrode; a step of machining the recess into a through hole that penetrates from the first surface to the second surface by cutting the substrate from the second surface side so that the electrode partially protrudes beyond the second surface to the second side, and machining the electrode into a through electrode that is located inside the through hole, partially protrudes beyond the second surface to the second side, and at least partially contains solder.

[0014] The step of forming the electrode may include the step of filling the recess with solder paste.

[0015] The step of forming the electrode includes: forming a first conductive layer on the inner surface of the recess; forming a second conductive layer containing the solder on the first conductive layer.

[0016] The step of forming the electrode may further include the step of forming a third conductive layer on the second conductive layer.

[0017] the electronic component has an electrode exposed on the first side; The step of mounting the electronic component on the first surface and electrically connecting the electronic component to the electrode inside the recess includes: bonding the electronic component to the first surface; forming an insulating layer having insulating properties on the first surface, on the electrode inside the recess, and on the electronic component; The method may also include a step of forming a conductive layer having a first portion located on the insulating layer, a second portion penetrating the insulating layer from the first portion to the electrode inside the recess, and a third portion penetrating the insulating layer from the first portion to the electrode of the electronic component. [Effects of the Invention]

[0018] According to the present disclosure, it is possible to suppress the thickness and reduce the number of manufacturing steps. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a cross-sectional view showing an electronic component mounting substrate according to an embodiment of the present invention. [Figure 2] 5A to 5C are cross-sectional views showing a method for manufacturing an electronic component mounting substrate according to the present embodiment. [Figure 3] 3A to 3C are cross-sectional views showing the method for manufacturing an electronic component mounting board according to the present embodiment, following FIG. 2. [Figure 4] 4A to 4C are cross-sectional views showing the method for manufacturing an electronic component mounting board according to the present embodiment, following FIG. 3. [Figure 5] FIG. 3 is a cross-sectional view showing an electronic component mounting board according to a first modified example of the present embodiment. [Figure 6] 5A to 5C are cross-sectional views showing a method for manufacturing an electronic component mounting board according to a first modified example of the present embodiment. [Figure 7] 7A to 7C are cross-sectional views showing the method for manufacturing an electronic component mounting board according to a first modified example of the present embodiment, following FIG. 6. [Figure 8] 8A to 8C are cross-sectional views showing the method for manufacturing an electronic component mounting board according to a first modified example of the present embodiment, following FIG. 7. [Figure 9] 9A to 9C are cross-sectional views showing a manufacturing method different from that shown in FIGS. 6 to 8 for an electronic component mounting board according to a first modified example of the present embodiment. [Figure 10] 10A to 10C are cross-sectional views showing the method for manufacturing an electronic component mounting board according to a first modified example of the present embodiment, following FIG. 9. [Figure 11] FIG. 10 is a cross-sectional view showing an electronic component mounting board according to a second modified example of the present embodiment. [Figure 12] FIG. 10 is a cross-sectional view showing an electronic component mounting board according to a third modified example of the present embodiment. [Figure 13] 13 is a cross-sectional view showing an electronic component mounting board according to a third modified example of the present embodiment, which is different from that shown in FIG. [Figure 14] 1A and 1B are diagrams illustrating examples of products on which an electronic component mounting board is mounted. DETAILED DESCRIPTION OF THE INVENTION

[0020] The configuration of an electronic component mounting substrate and a manufacturing method thereof according to an embodiment of the present disclosure will be described in detail below with reference to the drawings. Note that the embodiments described below are merely examples of the present disclosure, and the present disclosure should not be construed as being limited to these embodiments. Furthermore, in this specification, terms such as "substrate," "substrate," "sheet," and "film" are not distinguished from one another solely based on differences in nomenclature. For example, "substrate" and "substrate" are concepts that include components that may be called sheets or films. Furthermore, terms used in this specification that specify shapes, geometric conditions, and their degrees, such as "parallel" and "orthogonal," as well as values ​​of length and angle, are not limited to their strict meanings but are interpreted to include the extent to which similar functions can be expected. In the drawings referenced in this embodiment, identical or similar symbols are used to designate identical or similarly functional parts, and repeated explanations may be omitted. Also, for convenience of explanation, the dimensional ratios in the drawings may differ from the actual ratios, and some components may be omitted from the drawings.

[0021] (Electronic component mounting board 1) Hereinafter, embodiments of the present disclosure will be described. First, the configuration of an electronic component mounting substrate 1 according to the present embodiment will be described. The electronic component mounting substrate 1 of the present embodiment can be used, for example, as an interposer substrate that relays between a motherboard and electronic components. Fig. 1 is a cross-sectional view showing the electronic component mounting substrate 1 according to the present embodiment.

[0022] 1, the electronic component mounting substrate 1 includes a substrate 10, a through electrode 20, an electronic component 30, an organic layer 40 which is an example of an insulating layer, and a conductive layer 50. Each of the components of the electronic component mounting substrate 1 will be described below.

[0023] (Substrate 10) The substrate 10 includes a first surface 11 on an upper side D1 in the thickness direction D, which is an example of a first side, and a second surface 12 on a lower side D2 in the thickness direction D, which is an example of a second side opposite to the first side. Note that the upper side D1 and the lower side D2 merely represent the directions in FIG. 1 , and the upper side D1 and the lower side D2 may be reversed depending on the orientation of the electronic component mounting board 1. The substrate 10 also has a plurality of through holes 13 that penetrate from the first surface 11 to the second surface 12.

[0024] The substrate 10 includes an inorganic material having a certain degree of insulating properties. For example, the substrate 10 is a glass substrate, a quartz substrate, a sapphire substrate, a resin substrate, a silicon substrate, a silicon carbide substrate, an alumina (Al2O3) substrate, an aluminum nitride (AlN) substrate, a zirconia oxide (ZrO2) substrate, or a laminate of these substrates. The substrate 10 may partially include a substrate made of a conductive material, such as an aluminum substrate or a stainless steel substrate.

[0025] Examples of glass used for the substrate 10 include alkali-free glass. Alkali-free glass is glass that does not contain alkali components such as sodium or potassium. Alkali-free glass contains, for example, boric acid instead of alkali components. Alkali-free glass also contains alkaline earth metal oxides such as calcium oxide or barium oxide. Substrates containing glass are suitable for electronic component mounting substrates 1 that require transparency, such as electronic component mounting substrates 1 for camera modules. In addition to electronic component mounting substrates 1 for camera modules, glass-containing substrates are also used as substrates for mounting high-performance LSIs, such as servers and supercomputers. This is because glass has lower signal transmission loss than silicon substrates and is suitable for signal processing in the GHz band.

[0026] In the example of FIG. 1 , through hole 13 has a circular shape in a cross section perpendicular to the thickness direction D of substrate 10. Furthermore, the inner diameter of through hole 13, i.e., the width of the cross section perpendicular to the thickness direction D, decreases from first surface 11 to second surface 12. The inner diameter of through hole 13 may decrease linearly at a constant decreasing rate from first surface 11 to second surface 12, or may decrease quadratically. Through hole 13 whose inner diameter decreases from first surface 11 to second surface 12 can be easily processed by a combination of laser irradiation and wet etching. The inner diameter of through hole 13 may be constant, may increase from first surface 11 to second surface 12, or may decrease or increase toward the center of thickness direction D. Furthermore, the shape of the cross section perpendicular to the thickness direction D of through hole 13 is not limited to a circular shape, and may be, for example, a polygonal shape.

[0027] (Through electrode 20) The through electrode 20 is a conductive member located inside the through hole 13. In the example of FIG.

[0028] The through electrode 20 has a portion 20a within a predetermined range on the lower side D2 that protrudes toward the lower side D2 beyond the second surface 12. That is, the through electrode 20 partially protrudes toward the lower side D2 beyond the second surface 12. Hereinafter, the portion 20a within a predetermined range on the lower side D2 of the through electrode 20 will also be referred to as a protruding portion 20a.

[0029] 1, the through electrode 20 contains solder powder. The particle size of the solder powder is, for example, 0.5 μm to 3 μm. The solder contains tin (Sn) as a main component. The solder may further contain at least one of silver (Ag) and copper (Cu).

[0030] The protrusions 20a are coated with flux to prevent oxidation, and are then reflowed in a reducing atmosphere to deform into a spherical shape, allowing them to function properly as solder bumps that are electrically connected to the motherboard.

[0031] Since the through electrode 20 contains solder and has a protrusion 20a protruding from the second surface 12, it is possible to omit the process of providing a solder bump separate from the through electrode 20 on the underside D2 of the through electrode 20 for electrical connection with the motherboard.

[0032] The through electrodes 20 may be formed, for example, by printing and filling a solder paste having an appropriate viscosity obtained by adding flux to solder powder.

[0033] (Electronic Components 30) The electronic component 30 is located on the first surface 11 and is electrically connected to the through electrode 20 via a conductive layer 50, which will be described later. The electronic component 30 transmits or receives an electrical signal through the conductive layer 50 and the through electrode 20.

[0034] The electronic component 30 has electrodes 30a, i.e., terminals, exposed on the upper side D1. The electronic component 30 is, for example, a device chip such as an LSI (Large-Scale Integration), a MEMS (Micro Electro Mechanical Systems), or a discrete component.

[0035] The electronic component 30 has an end face 30b on its lower side D2 in contact with the first surface 11 while being electrically insulated from the through electrode 20. Hereinafter, the end face 30b on the lower side D2 of the electronic component 30 will also be referred to as the lower end face 30b. More specifically, the lower end face 30b of the electronic component 30 is adhered to the first surface 11 via an adhesive material (not shown), such as a die attachment material.

[0036] (Organic layer 40) The organic layer 40 is located on the first surface 11, on the through electrodes 20, and on the electronic components 30, and is a layer that contains an organic material and has insulating properties.

[0037] The organic layer 40 may contain an organic material having a dielectric loss tangent of 0.003 or less, preferably 0.002 or less, and more preferably 0.001 or less. Examples of organic materials that can be used for the organic layer 40 include polyimide and epoxy resin. By using an organic material with a small dielectric loss tangent for the organic layer 40, it is possible to prevent a portion of the electrical signal that should pass through the through electrode 20 and the conductive layer 50 from passing through the organic layer 40. This allows the bandwidth of the electronic component mounting substrate 1 to be expanded toward the high frequency side.

[0038] The organic layer 40 may be formed, for example, by exposure and development processes using a photosensitive film containing an organic material, or by applying a liquid containing an organic material by spin coating and drying it.

[0039] (Conductive layer 50) The conductive layer 50 is a conductive layer that is partially located on the organic layer 40 and electrically connected to the through-electrodes 20 and the electrodes 30 a of the electronic components 30 .

[0040] The conductive layer 50 has a first portion 51 located on the organic layer 40, a second portion 52 that penetrates the organic layer 40 from the first portion 51 to the through-electrode 20, and a third portion 53 that penetrates the organic layer 40 from the first portion 51 to the electrode 30a of the electronic component 30. The second portion 52 and the third portion 53 can also be called posts. The conductive layer 50 is electrically connected to the through-electrode 20 by the second portion 52. The conductive layer 50 is electrically connected to the electronic component 30 by the third portion 53.

[0041] In this way, by electrically connecting the electronic component 30 and the through electrode 20 via the conductive layer 50, the electronic component 30 can be easily mounted without requiring a bump. Note that the conductive layer 50 may have a portion that is electrically insulated from the electronic component 30 and the through electrode 20.

[0042] The conductive layer 50 may include a seed layer and a plating layer located on the seed layer. The seed layer is a conductive layer that serves as a base for depositing metal ions in a plating solution to grow the plating layer during the electroplating process to form the plating layer by electroplating. A conductive material such as copper can be used as the material for the seed layer. The material of the seed layer may be the same as or different from the material of the plating layer. For example, the seed layer may be a laminate film in which titanium and copper are sequentially stacked, or chromium. The seed layer may be formed by, for example, a sputtering method, a vapor deposition method, or an electroless plating method. The plating layer is a conductive layer formed by a plating process. The plating layer contains copper. The plating layer may contain an alloy of copper and a metal other than copper, such as gold, silver, platinum, rhodium, tin, aluminum, nickel, or chromium, or may be a laminate of copper and a metal other than copper.

[0043] (Method of manufacturing electronic component mounting substrate 1) An example of a method for manufacturing the electronic component mounting board 1 will be described below with reference to FIGS.

[0044] (Step of forming recess 130) FIG. 2 is a cross-sectional view showing a method for manufacturing an electronic component mounting board 1 according to this embodiment. First, a substrate 10 is prepared. To ensure that the substrate 10 has sufficient mechanical strength to withstand processing, the substrate 10 before processing shown in FIG. 2 is thicker than the substrate 10 after processing shown in FIG. 1. For example, if the thickness of the substrate 10 after processing is set to 100 μm, the thickness of the substrate 10 before processing may be 400 to 700 μm. After preparing the substrate 10, a laser beam is irradiated onto the substrate 10 from the first surface 11 side to form a recess 130 extending from the first surface 11 toward the lower side D2, as shown in FIG. 2. The recess 130 has a shape of a through-hole 13 in part, and is processed into the through-hole 13 by removing the inner bottom surface of the recess 130 in a thinning process of the substrate 10, which will be described later.

[0045] An excimer laser, an Nd:YAG laser, a femtosecond laser, or the like can be used as a laser for forming the recesses 130. When an Nd:YAG laser is used, a fundamental wave with a wavelength of 1064 nm, a second harmonic with a wavelength of 532 nm, a third harmonic with a wavelength of 355 nm, or the like can be used.

[0046] Furthermore, laser irradiation and wet etching can be appropriately combined to form the recesses 130. Specifically, first, an altered layer is formed by laser irradiation in the region of the substrate 10 where the recesses 130 are to be formed. After the altered layer is formed, the substrate 10 is immersed in hydrogen fluoride or the like to etch the altered layer. In this way, the recesses 130 can be formed in the substrate 10. Alternatively, the recesses 130 can be formed by a blasting process in which an abrasive is sprayed onto the substrate 10, or by a dry etching method such as reactive ion etching or deep reactive ion etching using a resist layer as a mask, or by a wet etching method.

[0047] (Step of forming electrode 200) After forming the recess 130, an electrode 200 is formed inside the recess 130 as shown in FIG. 2. The electrode 200 has the same configuration as the through electrode 20 shown in FIG. 1, but is referred to as the electrode 200 because it is not located inside the through hole 13 at this stage. In the example of FIG. 2, the electrode 200 can be formed by printing and filling the inside of the recess 130 with solder paste. At this time, printing the solder paste in a vacuum state can prevent voids from occurring in the electrode 200. In addition, the solder paste can be, for example, Sn(96.5)-Ag(3.0)-Cu(0.5) solder powder containing flux (rosin resin, solvent, additives).

[0048] (Electronic component 30 mounting process) FIG. 3 is a cross-sectional view illustrating the manufacturing method of the electronic component mounting substrate 1 according to this embodiment, subsequent to FIG. 2 . After forming the electrodes 200, as shown in FIG. 3 , the electronic component 30 is mounted on the first surface 11. Specifically, alignment marks indicating the mounting position of the electronic component 30 are formed on the first surface 11, and then, for example, a film-like die attachment material is placed at the mounting position. The alignment marks may be formed from the same material as the electrodes 200 in the process of forming the electrodes 200, or may be formed from a different material from the through electrodes 20 in a process different from the process of forming the through electrodes 20. After placing the die attachment material, while checking the alignment marks, the electronic component 30 is placed at the mounting position with its circuit surface including its electrodes 30a facing upward D1, face up. This allows the electronic component 30 to be bonded, i.e., temporarily fixed, to the first surface 11 by the adhesive strength of the die attachment material.

[0049] (Step of forming organic layer 40) After mounting the electronic component 30, as shown in FIG. 3, the organic layer 40 is formed on the first surface 11, the electrode 200, and the electronic component 30. At this time, as shown in FIG. 3, a first through-hole 40a penetrating the organic layer 40 in the thickness direction D to the electrode 200 and a second through-hole 40b penetrating the organic layer 40 in the thickness direction D to the electrode 30a of the electronic component 30 are simultaneously formed with the organic layer 40. For example, first, a film having a photosensitive layer containing an organic material and a base material is attached to the first surface 11 side of the substrate 10. Next, the film is subjected to an exposure process and a development process. As a result, the organic layer 40 made of the photosensitive layer of the film and having the first through-hole 40a and the second through-hole 40b formed therein can be formed on the first surface 11 side of the substrate 10.

[0050] (Process of forming conductive layer 50) 4 is a cross-sectional view showing the method for manufacturing the electronic component mounting substrate 1 according to this embodiment, subsequent to FIG. 3. After forming the organic layer 40, as shown in FIG. 4, a conductive layer 50 is formed on the organic layer 40. At this time, a second portion 52 is formed inside the first through-hole 40a, and a third portion 53 is formed inside the second through-hole 40b. By forming the conductive layer 50, the electronic component 30 and the electrode 200 are electrically connected via the conductive layer 50. The conductive layer 50 may be formed by patterning a seed layer and a plating layer by photolithography using a resist layer as a mask.

[0051] (Process for thinning the substrate 10) After the conductive layer 50 is formed, a thinning step is performed on the substrate 10, in which the substrate 10 is ground from the second surface 12 side so that the protruding portion 20a shown in Fig. 1 protrudes downward D2 from the second surface 12. In the thinning step, first, the substrate 10 is ground from the second surface 12 side by physical polishing using a grindstone until the thickness of the substrate 10 becomes the same as the thickness of the electrode 200.

[0052] After the physical polishing, the substrate 10 is polished by wet etching using a chemical solution having a high selectivity for the material of the substrate 10 relative to the solder that is the material of the electrode 200, until the protrusions 20a protrude beyond the second surface 12. When the material of the substrate 10 is glass, for example, a hydrofluoric acid-based chemical solution can be suitably used as the chemical solution.

[0053] By grinding the substrate 10 until the protruding portion 20a protrudes, the inner bottom surface of the recess 130 is removed, and the recess 130 is processed into a through hole 13 that penetrates the substrate 10. Furthermore, the electrode 200 is processed into a through electrode 20 located inside the through hole 13. At this time, the protruding amount of the protruding portion 20a can be easily adjusted by adjusting the etching time of the substrate 10 by wet etching. For example, if the thickness of the through electrode 20 is 150 μm, the protruding portion 20a can protrude 50 μm from the second surface 12 by grinding the substrate 10 until it is 100 μm thick.

[0054] Through the above steps, the electronic component mounting board 1 shown in Fig. 1 is obtained. The effects brought about by this embodiment will now be described.

[0055] According to this embodiment, the thickness of the substrate 10 can be made thinner than the thickness of the through electrodes 20. By making the thickness of the substrate 10 thinner, the thickness of the electronic component mounting board 1 can be reduced.

[0056] Furthermore, according to this embodiment, the through electrodes 20 contain solder and partially protrude from the second surface 12 of the substrate 10, so that the through electrodes 20 can also serve as solder bumps. By having the through electrodes 20 also serve as solder bumps, it is possible to omit the step of forming solder bumps separate from the through electrodes 20. In other words, according to this embodiment, the number of steps in manufacturing the electronic component mounting substrate 1 can be reduced.

[0057] Furthermore, according to this embodiment, unlike the conventional flip-chip bonding method, the electronic component 30 can be mounted using wiring technology without the need for bump formation, which allows the electronic component 30 to be easily mounted on the substrate 10.

[0058] Furthermore, according to this embodiment, the through electrodes 20 allow access to the electronic component 30 from both the first surface 11 side and the second surface 12 side, thereby improving the transmission efficiency of electrical signals.

[0059] Furthermore, if the substrate 10 contains glass, the signal transmission loss can be reduced.

[0060] (First Modification) Next, a first modified example of the electronic component mounting board 1 having the through electrodes 20 formed by solder plating will be described. Fig. 5 is a cross-sectional view showing the electronic component mounting board 1 according to the first modified example of this embodiment. Fig. 1 illustrates an example of the electronic component mounting board 1 having the through electrodes 20 formed by solder paste. In contrast, the electronic component mounting board 1 of the first modified example has the through electrodes 20 formed by solder plating.

[0061] Specifically, as shown in FIG. 5, in the electronic component mounting substrate 1 according to the first modified example, the through electrode 20 has a seed layer 21, which is an example of a first conductive layer, and a solder plating layer 22, which is an example of a second conductive layer.

[0062] Seed layer 21 is an electrically conductive layer located on sidewall 131 of through-hole 13, and partially protruding at protruding portion 20a to a lower side D2 below second surface 12. Seed layer 21 may have, for example, a single-layer structure containing copper or titanium as a main component, or may have a laminated structure of a layer containing titanium as a main component and a layer containing copper as a main component.

[0063] The solder plating layer 22 is located on the seed layer 21 and is a conductive layer containing solder. For example, a ternary plating of Sn(96.5)-Ag(3.0)-Cu(0.5) can be used as the solder plating layer 22.

[0064] An example of a method for manufacturing the electronic component mounting board 1 according to the first modified example will be described below, focusing on differences from the manufacturing method shown in FIGS.

[0065] 6 is a cross-sectional view showing a method for manufacturing an electronic component mounting board 1 according to a first modified example of the present embodiment. As shown in Fig. 6, in the first modified example, in the step of forming the electrode 200, first, a seed layer 21 is formed on the inner surface of the recess 130 and on the first surface 11. The seed layer 21 is formed by, for example, a sputtering method, a vapor deposition method, or an electroless plating method.

[0066] Fig. 7 is a cross-sectional view showing the method for manufacturing an electronic component mounting board 1 according to a first modified example of this embodiment, following Fig. 6. After forming the seed layer 21, as shown in Fig. 7, a solder plating layer 22 is formed on the seed layer 21. The solder plating layer 22 is formed by, for example, electrolytic plating.

[0067] 8 is a cross-sectional view showing a method for manufacturing an electronic component mounting board 1 according to a first modified example of this embodiment, following FIG. 7. After forming the solder plating layer 22, as shown in FIG. 8, the seed layer 21 and the solder plating layer 22 located on the upper side D1 of the first surface 11 are removed. The seed layer 21 and the solder plating layer 22 are removed by, for example, CMP (chemical mechanical polishing). Subsequent steps are the same as those shown in FIGS. 3 and 4.

[0068] Another example of the method for manufacturing the electronic component mounting substrate 1 according to the first modified example will be described below, focusing on differences from the manufacturing method shown in Figures 2 to 4. Figure 9 is a cross-sectional view showing a manufacturing method for the electronic component mounting substrate 1 according to the first modified example of this embodiment, which is different from the manufacturing method shown in Figures 6 to 8. In the example of Figure 9, a resist layer 6 is formed on a seed layer 21 formed on the first surface 11 by processing a dry film by photolithography, for example.

[0069] Fig. 10 is a cross-sectional view showing the method for manufacturing an electronic component mounting board according to a first modified example of this embodiment, subsequent to Fig. 9. After forming the resist layer 6, as shown in Fig. 10, using the resist layer 6 as a mask, a solder plating layer 22 is formed by, for example, electrolytic plating on the seed layer 21 on the inner surface of the recess 130 that is not covered with the resist layer 6.

[0070] After the solder plating layer 22 is formed, the resist layer 6 is peeled off, and then the solder plating layer 22 and the seed layer 21 on the upper side D1 of the first surface 11 are removed by etching. The subsequent steps are the same as those in FIGS. 3 and 4.

[0071] According to the first modification, when the protruding portion 20a of the through electrode 20 is processed into a solder bump by reflow, the seed layer 21 melts and mixes with the solder plating layer 22, thereby forming an alloy layer between the solder and the metal of the seed layer 21. By forming an alloy layer, the electrical conductivity and mechanical strength of the solder bump formed by the protruding portion 20a of the through electrode 20 can be improved. By using a solder bump with improved electrical conductivity and mechanical strength, good electrical and mechanical connection can be achieved between the through electrode 20 and the electrode of the motherboard. Note that, to further improve the electrical and mechanical connection between the through electrode 20 and the electrode of the motherboard, it is desirable that the seed layer 21 and the electrode of the motherboard contain the same material, such as copper.

[0072] (Second Modification) Next, a second modified example of the electronic component mounting board 1 having the through electrodes 20 formed by solder plating will be described. Fig. 11 is a cross-sectional view showing the electronic component mounting board 1 according to the second modified example of this embodiment.

[0073] 11, in the electronic component mounting substrate 1 according to the second modification, the through electrode 20 further includes a metal plating layer 23, which is an example of a third conductive layer, in addition to the configuration of FIG. 5. The metal plating layer 23 is located on the solder plating layer 22. The metal plating layer 23 may contain the same metal as the conductive layer 50 and the seed layer 21, such as copper. The metal plating layer 23 may be formed by, for example, electrolytic plating.

[0074] According to the second variant, even if the recess 130 cannot be sufficiently filled with solder during the process of forming the solder plating layer 22, the dimensional accuracy and reliability of the electrical connection of the entire through electrode 20 can be ensured by forming the metal plating layer 23 on the solder plating layer 22.

[0075] (Third Modification) Next, a third modified example in which electronic components 30 are stacked will be described. Fig. 12 is a cross-sectional view showing an electronic component mounting board 1 according to the third modified example of the present embodiment. Fig. 13 is a cross-sectional view showing an electronic component mounting board 1 according to the third modified example of the present embodiment, which is different from that shown in Fig. 12.

[0076] The electronic component mounting substrate 1 of this embodiment shown in FIG. 1 has a conductive layer 50 on the electronic component 30 mounted face-up, and is therefore also suitable for stacking other electronic components on the electronic component 30.

[0077] For example, as shown in FIG. 12, it is also possible to electrically connect a second-layer electronic component 30_2 face-down onto the conductive layer 50 via a bump, and seal the electronic component 30_2 with a second organic layer 40_2.

[0078] 13, it is also possible to stack a second-layer electronic component mounting substrate 1_2 having the same structure on a first-layer electronic component mounting substrate 1. In the example of FIG. 13, the second-layer electronic component mounting substrate 1_2 is electrically connected to the conductive layer 50 of the first-layer electronic component mounting substrate 1 via solder bumps B_20a formed by processing the protruding portions 20a of the through electrodes 20 by reflow soldering. Although not shown, it is preferable that the space between the first-layer electronic component mounting substrate 1 and the second-layer electronic component mounting substrate 1_2 be sealed with an organic layer.

[0079] (Example of a product equipped with an electrode board) 14 is a diagram showing examples of products on which the electronic component mounting board 1 according to this embodiment can be mounted. The electronic component mounting board 1 according to this embodiment can be used in a variety of products. For example, it can be mounted in a notebook personal computer 110, a tablet terminal 120, a mobile phone 130, a smartphone 140, a digital video camera 150, a digital camera 160, a digital clock 170, a server 180, etc. [Explanation of symbols]

[0080] 1. Electronic component mounting board 10 Substrate 11 Page 1 12 Side 2 20 Through electrode 30 Electronic Components

Claims

1. a substrate having a first surface on a first side and a second surface on a second side opposite to the first side, the substrate having a through hole extending from the first surface to the second surface; a through electrode located inside the through hole, partially protruding beyond the second surface toward the second side, and at least partially containing solder; an electronic component located on the first surface and electrically connected to the through electrode; an insulating layer having insulating properties and located on the first surface, the through electrode, and the electronic component; a conductive layer that is partially located on the first side of the insulating layer and electrically connected to the through electrode and the electronic component, the insulating layer has a portion in contact with the conductive layer on the first side, a portion not in contact with the conductive layer on the first side, a portion in contact with the substrate on the second side, and a portion not in contact with the substrate on the second side; the insulating layer is in contact with the through electrode and the substrate on the second side so as to straddle the through electrode and the substrate.

2. The electronic component mounting substrate according to claim 1 , wherein the through electrode contains solder powder containing copper.

3. The through electrode is Partially contains solder containing copper, a first conductive layer; 2. The electronic component mounting substrate according to claim 1, further comprising: a second conductive layer located on the first conductive layer and containing the solder.

4. The electronic component mounting board according to claim 3 , wherein the through electrode further comprises a third conductive layer located on the second conductive layer.

5. The conductive layer is a first portion located on the insulating layer; a second portion that penetrates the insulating layer from the first portion to the through electrode; a third portion that penetrates the insulating layer from the first portion to an electrode located on the electronic component; The electronic component mounting substrate according to claim 1 , wherein

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