JP6962052B2 - Electronic component mounting board and its manufacturing method - Google Patents

Description

The present disclosure relates to an electronic component mounting substrate and a method for manufacturing the same.

Conventionally, various techniques related to an electronic component mounting board on which electronic components are mounted have been proposed. For example, Patent Document 1 discloses a technique for relaying a wiring board and an IC chip by an interposer. In the technique described in Patent Document 1, an IC chip arranged on the upper surface side and a wiring board arranged on the lower surface side are electrically connected by an interposer having a glass substrate and a filled via conductor penetrating from the upper surface to the lower surface of the glass substrate. Is connected.

Japanese Unexamined Patent Publication No. 2014-139963

However, in the technique described in Patent Document 1, since the thickness of the glass substrate is the same as the thickness of the filled via conductor, there is a problem that it is difficult to suppress the thickness of the interposer. Further, in the technique described in Patent Document 1, in order to electrically connect the filled via conductor to the wiring board, it is necessary to provide a solder bump separate from the filled via conductor at the lower end of the filled via conductor via a substrate connection terminal. rice field. Therefore, the technique described in Patent Document 1 has a problem that it is difficult to reduce the manufacturing man-hours.

The present disclosure has been made in consideration of the above points, and an object of the present disclosure is to provide an electronic component mounting substrate and a method for manufacturing the same, which can suppress the thickness and reduce the manufacturing man-hours.

In order to solve the above problems, in one aspect of the present disclosure,
A substrate having a first surface on the first side and a second surface on the second side opposite to the first side, and provided with a through hole penetrating from the first surface to the second surface. When,
A through electrode located inside the through hole, partially projecting from the second surface to the second side, and at least partially containing solder.
Provided is an electronic component mounting substrate, which is located on the first surface and includes an electronic component electrically connected to the through electrode.

The through electrode may contain solder powder.

The through electrode is
Partially contains the solder,
A first conductive layer located on the side wall of the through hole and partially protruding toward the second side from the second surface.
It may have a second conductive layer located on the first conductive layer and containing the solder.

The through electrode may further have a third conductive layer located on the second conductive layer.

The electronic component has an exposed electrode on the first side.
The electronic component mounting board is
An insulating layer located on the first surface, on the through electrode, and on the electronic component and having an insulating property.
A conductive layer that is partially located on the insulating layer and is electrically connected to the through electrode and the electrode of the electronic component may be further provided.

The conductive layer is
The first portion located on the insulating layer and
A second portion penetrating the insulating layer from the first portion to the through electrode,
It may have a third portion penetrating the insulating layer from the first portion to the electrode of the electronic component.

The substrate may contain glass.

In another aspect of the disclosure,
A step of preparing a substrate having a first surface on the first side and a second surface on the second side opposite to the first side.
A step of forming a recess in the substrate from the first surface toward the second side, and
A step of forming an electrode containing solder at least partially inside the recess, and
A step of mounting an electronic component on the first surface and electrically connecting the electronic component to the electrode.
By scraping the substrate from the second surface side so that the electrode partially protrudes from the second surface to the second surface, the recess is penetrated from the first surface to the second surface. The electrode is processed into a through hole to be formed, and the electrode is located inside the through hole and partially protrudes from the second surface to the second side to become a through electrode containing at least a part of solder. Provided is a method of manufacturing a substrate on which an electronic component is mounted, which comprises a process of processing.

The step of forming the electrode may include a step of filling the inside of the recess with a solder paste.

The step of forming the electrode is
The step of forming the first conductive layer on the inner surface of the recess and
A step of forming a second conductive layer containing the solder on the first conductive layer may be provided.

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

The electronic component has an exposed electrode 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 is described.
The step of adhering the electronic component to the first surface and
A step of forming an insulating layer having an insulating property on the first surface, on the electrode inside the recess, and on the electronic component.
The first portion located on the insulating layer, the second portion penetrating the insulating layer from the first portion to the electrode inside the recess, and the insulation from the first portion to the electrode of the electronic component. It may have a step of forming a conductive layer having a third portion penetrating the layer.

According to the present disclosure, the thickness can be suppressed and the manufacturing man-hours can be reduced.

It is sectional drawing which shows the electronic component mounting substrate by this embodiment. It is sectional drawing which shows the manufacturing method of the electronic component mounting substrate by this embodiment. It is sectional drawing which shows the manufacturing method of the electronic component mounting substrate by this embodiment following FIG. It is sectional drawing which shows the manufacturing method of the electronic component mounting substrate by this embodiment following FIG. It is sectional drawing which shows the electronic component mounting substrate by the 1st modification of this embodiment. It is sectional drawing which shows the manufacturing method of the electronic component mounting substrate by 1st modification of this Embodiment. FIG. 5 is a cross-sectional view showing a method of manufacturing an electronic component mounting substrate according to a first modification of the present embodiment following FIG. FIG. 5 is a cross-sectional view showing a method of manufacturing an electronic component mounting substrate according to a first modification of the present embodiment following FIG. 7. FIG. 5 is a cross-sectional view showing a manufacturing method different from FIGS. 6 to 8 of the electronic component mounting substrate according to the first modification of the present embodiment. FIG. 5 is a cross-sectional view showing a method of manufacturing an electronic component mounting substrate according to a first modification of the present embodiment following FIG. It is sectional drawing which shows the electronic component mounting substrate by the 2nd modification of this embodiment. It is sectional drawing which shows the electronic component mounting substrate by the 3rd modification of this embodiment. It is sectional drawing which shows the electronic component mounting substrate by the 3rd modification of this embodiment different from FIG. It is a figure which shows the example of the product which mounts an electronic component mounting board.

Hereinafter, the configuration of the electronic component mounting substrate and the manufacturing method thereof according to the embodiment of the present disclosure will be described in detail with reference to the drawings. The embodiments shown below are examples of the present embodiments, and the present disclosure is not construed as being limited to these embodiments. Further, in the present specification, terms such as "base material", "base material", "sheet" and "film" are not distinguished from each other based only on the difference in designation. For example, "base material" and "base material" are concepts including members that can be called sheets or films. Furthermore, the terms used in this specification, such as "parallel" and "orthogonal", and the values of length and angle, which specify the shape and geometric conditions and their degrees, are bound by a strict meaning. Instead, the interpretation will include the range in which similar functions can be expected. Further, in the drawings referred to in the present embodiment, the same parts or parts having similar functions are designated by the same reference numerals or similar reference numerals, and the repeated description thereof may be omitted. In addition, the dimensional ratio of the drawing may differ from the actual ratio for convenience of explanation, or a part of the configuration may be omitted from the drawing.

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

As shown in FIG. 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. Hereinafter, each component of the electronic component mounting substrate 1 will be described.

(Board 10)
The substrate 10 has a first surface 11 of the upper D1 in the thickness direction D, which is an example of the first side, and a second surface D2 of the lower D2 in the thickness direction D, which is an example of the second side opposite to the first side. Includes surface 12. The upper D1 and the lower D2 merely represent the directions in FIG. 1, and the upper D1 and the lower D2 may be reversed depending on the orientation of the electronic component mounting substrate 1. Further, the substrate 10 is provided with a plurality of through holes 13 penetrating from the first surface 11 to the second surface 12.

The substrate 10 contains an inorganic material having a certain insulating property. For example, the substrate 10 includes a glass substrate, a quartz substrate, a sapphire substrate, a resin substrate, a silicon substrate, a silicon carbide substrate, an alumina (Al ₂ O ₃ ) substrate, an aluminum nitride (AlN) substrate, a diriconia oxide (ZrO ₂ ) substrate, and the like. Alternatively, these substrates are laminated. The substrate 10 may partially include a substrate made of a conductive material such as an aluminum substrate or a stainless steel substrate.

Examples of the glass used in the substrate 10 include non-alkali glass. Non-alkali glass is glass that does not contain alkaline components such as sodium and potassium. Non-alkali glass contains, for example, boric acid instead of the alkaline component. The non-alkali glass also contains, for example, alkaline earth metal oxides such as calcium oxide and barium oxide. The glass-containing substrate can be suitably used for the electronic component mounting substrate 1 that requires transparency, for example, the electronic component mounting substrate 1 for a camera module. The glass-containing substrate is also used as a substrate for mounting a high-performance LSI such as a server and a superputer, in addition to the electronic component mounting substrate 1 for a camera module. This is because the signal transmission loss is small as compared with the silicon substrate, and it is suitable for signal processing in the GHz band.

In the example of FIG. 1, the through hole 13 has a circular shape in a cross section perpendicular to the thickness direction D of the substrate 10. Further, the inner diameter of the through hole 13, that is, the width of the cross section perpendicular to the thickness direction D decreases from the first surface 11 to the second surface 12. The inner diameter of the through hole 13 may decrease linearly at a constant rate of decrease from the first surface 11 to the second surface 12, or may decrease quadratically. The through hole 13 whose inner diameter decreases from the first surface 11 to the second surface 12 can be reasonably processed by a combination of laser irradiation and wet etching. The inner diameter of the through hole 13 may be constant, may increase from the first surface 11 toward the second surface 12, or may decrease or increase toward the central portion in the thickness direction D. Further, the shape of the cross section of the through hole 23 perpendicular to the thickness direction D is not limited to a circular shape, and may be, for example, a polygonal shape.

(Through Silicon Via 20)
The through electrode 20 is a member that is located inside the through hole 13 and has conductivity. In the example of FIG. 1, the through electrode 20 is filled inside the through hole 13.

In the through electrode 20, a portion 20a in a predetermined range of the lower D2 projects to the lower D2 from the second surface 12. That is, the through electrode 20 partially protrudes below D2 from the second surface 12. Hereinafter, the portion 20a in a predetermined range of the lower D2 of the through electrode 20 is also referred to as a protruding portion 20a.

In the example of FIG. 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.

The protruding portion 20a can properly function as a solder bump electrically connected to the motherboard by reflowing and deforming into a spherical shape in a reducing atmosphere with a flux applied to prevent oxidation.

Since the through electrode 20 contains solder and has a protruding portion 20a protruding from the second surface 12, a solder separate from the through electrode 20 for electrical connection with the mother boat on the lower D2 of the through electrode 20. It is possible to omit the step of providing the bump.

The through silicon via 20 may be formed, for example, by printing and filling a solder paste having an appropriate viscosity by adding a flux to the solder powder.

(Electronic component 30)
The electronic component 30 is located on the first surface 11 and is electrically connected to the through electrode 20 via the conductive layer 50 described later. The electronic component 30 transmits or receives an electrical signal through the conductive layer 50 and the through silicon via 20.

The electronic component 30 has an electrode 30a, that is, a terminal exposed on the upper D1. The electronic component 30 is a device chip such as an LSI (Large-Scale Integration), a MEMS (Micro Electro Mechanical Systems), and a discrete component.

The electronic component 30 is in contact with the first surface 11 on the end surface 30b of the lower side D2 in a state of being electrically insulated from the through electrode 20. Hereinafter, the end surface 30b of the lower D2 of the electronic component 30 is also referred to as a lower end surface 30b. More specifically, the lower end surface 30b of the electronic component 30 is adhered to the first surface 11 via an adhesive material (not shown) such as a diaphragm material.

(Organic layer 40)
The organic layer 40 is located on the first surface 11, the through electrode 20, and the electronic component 30, and is a layer containing an organic material and having an insulating property.

The organic layer 40 may contain an organic material having a dielectric loss tangent of 0.003 or less, preferably 0.002 or less, more preferably 0.001 or less. As the organic material of the organic layer 40, polyimide, epoxy resin or the like can be used. By constructing the organic layer 40 using an organic material having a small dielectric loss tangent, it is possible to prevent a part of the electric signal that should pass through the through electrode 20 and the conductive layer 50 from passing through the organic layer 40. As a result, the band of the electronic component mounting substrate 1 can be expanded to the high frequency side.

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

(Conductive layer 50)
The conductive layer 50 is a conductive layer that is partially located on the organic layer 40 and is electrically connected to the through electrode 20 and the electrode 30a of the electronic component 30.

The conductive layer 50 includes a first portion 51 located on the organic layer 40, a second portion 52 penetrating the organic layer 40 from the first portion 51 to the through electrode 20, and an electrode 30a of the electronic component 30 from the first portion 51. It has a third portion 53 that penetrates the organic layer 40 up to. The second part 52 and the third part 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.

By electrically connecting the electronic component 30 and the through electrode 20 via the conductive layer 50 in this way, the electronic component 30 can be easily mounted without requiring bumps. The conductive layer 50 may have a portion electrically insulated from the electronic component 30 and the through electrode 20.

The conductive layer 50 may have 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 growing the plating layer by precipitating metal ions in the plating solution during the electrolytic plating step of forming the plating layer by the electrolytic plating treatment. As the material of the seed layer, a conductive material such as copper can be used. 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 laminated film in which titanium and copper are laminated in this order, chromium, or the like. The seed layer may be formed by, for example, a sputtering method, a vapor deposition method, an electroless plating method, or the like. 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, for example, gold, silver, platinum, rhodium, tin, aluminum, nickel, chromium, or copper and a metal other than copper. It may be laminated.

(Manufacturing method of electronic component mounting substrate 1)
Hereinafter, an example of a method for manufacturing the electronic component mounting substrate 1 will be described with reference to FIGS. 2 to 4.

(Step of forming recess 130)
FIG. 2 is a cross-sectional view showing a method of manufacturing the electronic component mounting substrate 1 according to the present embodiment. First, the substrate 10 is prepared. The unprocessed substrate 10 shown in FIG. 2 is thicker than the processed substrate 10 shown in FIG. 1 so that the substrate 10 can exhibit sufficient mechanical strength to withstand the processing. For example, when the thickness of the substrate 10 after processing is 100 μm, the thickness of the substrate 10 before processing may be 400 to 700 μm. After preparing the substrate 10, the substrate 10 is irradiated with laser light from the first surface 11 side to form a recess 130 from the first surface 11 toward the lower D2 as shown in FIG. The recess 130 has a part of the shape of the through hole 13, and is processed into the through hole 13 by removing the inner bottom surface of the recess 130 in the thinning step of the substrate 10 described later.

As the laser for forming the recess 130, an excimer laser, an Nd: YAG laser, a femtosecond laser, or the like can be used. When the Nd: YAG laser is adopted, a fundamental wave having a wavelength of 1064 nm, a second harmonic having a wavelength of 532 nm, a third harmonic having a wavelength of 355 nm, and the like can be used.

Further, in order to form the recess 130, laser irradiation and wet etching can be appropriately combined. Specifically, first, a perverted layer is formed in a region of the substrate 10 on which the recess 130 should be formed by laser irradiation. After forming the altered layer, the substrate 10 is immersed in hydrogen fluoride or the like to etch the altered layer. As a result, the recess 130 can be formed in the substrate 10. In addition, the recess 130 may be formed by a blast treatment in which a polishing material is sprayed onto the substrate 10, or a dry etching method such as a reactive ion etching method or a deep digging reactive ion etching method using the resist layer as a mask. Alternatively, it may be formed by a wet etching method.

(Forming process of electrode 200)
After forming the recess 130, the electrode 200 is formed inside the recess 130 as shown in FIG. The electrode 200 has the same configuration as the through electrode 20 shown in FIG. 1, but is called the electrode 200 because it is not located inside the through hole 13 at this time. In the example of FIG. 2, the electrode 200 can be formed by printing and filling the inside of the recess 130 with a solder paste. At this time, by printing the solder paste in a vacuum state, it is possible to suppress the generation of voids in the electrode 200. Further, as the solder paste, for example, a solder powder of Sn (96.5) -Ag (3.0) -Cu (0.5) containing a flux (rosin resin, solvent, additive) is used. Can be done.

(Mounting process of electronic component 30)
FIG. 3 is a cross-sectional view showing a method of manufacturing the electronic component mounting substrate 1 according to the present embodiment following FIG. After forming the electrode 200, the electronic component 30 is mounted on the first surface 11 as shown in FIG. Specifically, after forming an alignment mark indicating the mounting position of the electronic component 30 on the first surface 11, for example, a film-shaped diaphragm attachment material is placed at the mounting position. The alignment mark may be formed of the same material as the electrode 200 in the process of forming the electrode 200, or may be formed of a material different from that of the through electrode 20 in a process different from the process of forming the through electrode 20. After arranging the diaphragm material, the electronic component 30 is placed at the mounting position in a face-up state with the circuit surface including the electrode 30a facing the upper side D1 while checking the alignment mark. As a result, the electronic component 30 can be adhered to or temporarily fixed to the first surface 11 by the adhesive force of the diaphragm material.

(Step of forming organic layer 40)
After mounting the electronic component 30, as shown in FIG. 3, an 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, the first through hole 40a penetrating the organic layer 40 in the thickness direction D up to the electrode 200 and the second through hole 40a penetrating the organic layer 40 in the thickness direction D up to the electrode 30a of the electronic component 30. The holes 40b are formed at the same time as 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 exposed and developed. As a result, the organic layer 40 composed of the photosensitive layer of the film and having the first through hole 40a and the second through hole 40b formed can be formed on the first surface 11 side of the substrate 10.

(Step of forming the conductive layer 50)
FIG. 4 is a cross-sectional view showing a method of manufacturing the electronic component mounting substrate 1 according to the present embodiment following FIG. After forming the organic layer 40, the conductive layer 50 is formed on the organic layer 40 as shown in FIG. At this time, the second portion 52 is formed inside the first through hole 40a, and the 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 the seed layer and the plating layer by photolithography using the resist layer as a mask.

(Thinning process of substrate 10)
After forming the conductive layer 50, a thinning step of the substrate 10 is performed by scraping the substrate 10 from the second surface 12 side so that the protruding portion 20a shown in FIG. 1 projects below the second surface 12 to D2. In the thinning step, first, the substrate 10 is scraped from the second surface 12 side until the thickness of the substrate 10 becomes the same as the thickness of the electrode 200 by physical polishing using a grindstone.

After physical polishing, the substrate 10 is scraped by wet etching using a chemical solution having a high selection ratio of the material of the substrate 10 to the solder which is the material of the electrode 200 until the protruding portion 20a protrudes from the second surface 12. When the material of the substrate 10 is glass, for example, a hydrofluoric acid-based chemical solution can be preferably used as the chemical solution.

By scraping 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 penetrating the substrate 10. Further, the electrode 200 is processed into a through electrode 20 located inside the through hole 13. At this time, by adjusting the etching time of the substrate 10 by wet etching, the amount of protrusion of the protruding portion 20a can be easily adjusted. For example, while the thickness of the through electrode 20 is 150 μm, the protrusion 20a can be projected by 50 μm from the second surface 12 by cutting the substrate 10 to a thickness of 100 μm.

By the above steps, the electronic component mounting substrate 1 shown in FIG. 1 is obtained. Hereinafter, the action brought about by this embodiment will be described.

According to this embodiment, the thickness of the substrate 10 can be made thinner than the thickness of the through electrode 20. By reducing the thickness of the substrate 10, the thickness of the electronic component mounting substrate 1 can be suppressed.

Further, according to the present embodiment, since the through electrode 20 contains solder and partially protrudes from the second surface 12 of the substrate 10, the through electrode 20 can also serve as a solder bump. Since the through electrode 20 also serves as a solder bump, the step of forming a solder bump separate from the through electrode 20 can be omitted. That is, according to the present embodiment, the man-hours for manufacturing the electronic component mounting substrate 1 can be reduced.

Further, according to the present embodiment, unlike the conventional flip-chip bonding method, the electronic component 30 can be mounted by the wiring technique without requiring the formation of bumps. As a result, the electronic component 30 can be easily mounted on the substrate 10.

Further, according to the present embodiment, by having the through electrode 20, the electronic component 30 can be accessed from both the first surface 11 side and the second surface 12 side. Thereby, the transmission efficiency of the electric signal can be improved.

Further, if the substrate 10 containing glass is used, the signal transmission loss can be reduced.

(First modification)
Next, a first modification of the electronic component mounting substrate 1 provided with the through silicon via 20 by solder plating will be described. FIG. 5 is a cross-sectional view showing the electronic component mounting substrate 1 according to the first modification of the present embodiment. In FIG. 1, an example of an electronic component mounting substrate 1 provided with a through electrode 20 made of solder paste has been described. On the other hand, the electronic component mounting substrate 1 of the first modification includes a through electrode 20 by solder plating.

Specifically, as shown in FIG. 5, in the electronic component mounting substrate 1 according to the first modification, the through electrodes 20 are an example of the seed layer 21 which is an example of the first conductive layer and an example of the second conductive layer. It has a certain solder plating layer 22.

The seed layer 21 is a conductive layer located on the side wall 131 of the through hole 13 and partially projecting to D2 below the second surface 12 at the projecting portion 20a. The seed layer 21 may have, for example, a single-layer structure containing copper or titanium as a main component, or a layer containing titanium as a main component and a layer containing copper as a main component. It may have a structure.

The solder plating layer 22 is a conductive layer located on the seed layer 21 and containing solder. As the solder plating layer 22, for example, Sn (96.5) -Ag (3.0) -Cu (0.5) ternary plating can be used.

Hereinafter, an example of the manufacturing method of the electronic component mounting substrate 1 according to the first modification will be described by limiting the differences from the manufacturing methods of FIGS. 2 to 4.

FIG. 6 is a cross-sectional view showing a method of manufacturing the electronic component mounting substrate 1 according to the first modification of the present embodiment. As shown in FIG. 6, in the first modification, in the step of forming the electrode 200, first, the 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 thin-film deposition method, an electroless plating method, or the like.

FIG. 7 is a cross-sectional view showing a method of manufacturing the electronic component mounting substrate 1 according to the first modification of the present embodiment following FIG. After forming the seed layer 21, the solder plating layer 22 is formed on the seed layer 21 as shown in FIG. 7. The solder plating layer 22 is formed by, for example, an electrolytic plating method.

FIG. 8 is a cross-sectional view showing a method of manufacturing the electronic component mounting substrate 1 according to the first modification of the present 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 D1 above the first surface 11 are removed. The seed layer 21 and the solder plating layer 22 are removed by, for example, CMP, that is, chemical mechanical polishing. Subsequent steps are the same as in FIGS. 3 and 4.

Hereinafter, another example of the method for manufacturing the electronic component mounting substrate 1 according to the first modification will be described by limiting the differences from the manufacturing methods of FIGS. 2 to 4. FIG. 9 is a cross-sectional view showing a manufacturing method different from FIGS. 6 to 8 of the electronic component mounting substrate 1 according to the first modification of the present embodiment. In the example of FIG. 9, the resist layer 6 is formed on the seed layer 21 formed on the first surface 11 by processing a dry film by, for example, photolithography.

FIG. 10 is a cross-sectional view showing a method of manufacturing an electronic component mounting substrate according to a first modification of the present embodiment following FIG. After forming the resist layer 6, as shown in FIG. 10, the resist layer 6 is used as a mask and soldered on the seed layer 21 on the inner surface of the recess 130 not covered with the resist layer 6, for example, by an electrolytic plating method. The plating layer 22 is formed.

After forming the solder plating layer 22, 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. Subsequent steps are the same as in FIGS. 3 and 4.

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, so that the solder and the seed layer 21 are mixed. It is possible to form an alloy layer with the metal of. By forming the alloy layer, the conductivity and mechanical strength of the solder bump due to the protruding portion 20a of the through electrode 20 can be increased. By using the solder bumps having increased conductivity and mechanical strength, the electrical and mechanical connection between the through electrode 20 and the electrode of the motherboard can be satisfactorily performed. It is desirable that the seed layer 21 and the electrode of the motherboard contain the same material such as copper in order to further improve the electrical and mechanical connection between the through electrode 20 and the electrode of the motherboard.

(Second modification)
Next, a second modification of the electronic component mounting substrate 1 provided with the through silicon via 20 by solder plating will be described. FIG. 11 is a cross-sectional view showing the electronic component mounting substrate 1 according to the second modification of the present embodiment.

As shown in FIG. 11, in the electronic component mounting substrate 1 according to the second modification, the through electrode 20 further has a metal plating layer 23, which is an example of the third conductive layer, in addition to the configuration of FIG. 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 such as copper and the seed layer 21. The metal plating layer 23 may be formed by, for example, an electrolytic plating method.

According to the second modification, even when the recess 130 cannot be sufficiently filled with solder in the process of forming the solder plating layer 22, the through electrode is formed by forming the metal plating layer 23 on the solder plating layer 22. 20 The overall dimensional accuracy and reliability of the electrical connection can be ensured.

(Third variant)
Next, a third modification in which the electronic components 30 are laminated will be described. FIG. 12 is a cross-sectional view showing the electronic component mounting substrate 1 according to the third modification of the present embodiment. FIG. 13 is a cross-sectional view showing an electronic component mounting substrate 1 according to a third modification of the present embodiment, which is different from FIG.

Since the electronic component mounting substrate 1 of the present embodiment shown in FIG. 1 includes the conductive layer 50 on the electronic component 30 mounted face-up, it is also suitable for laminating other electronic components on the electronic component 30. ing.

For example, as shown in FIG. 12, the electronic component 30_2 of the second layer is electrically connected on the conductive layer 50 in a face-down state via a bump, and the electronic component 30_2 is sealed with the organic layer 40_2 of the second layer. It is also possible to stop.

Further, as shown in FIG. 13, it is also possible to stack the second layer electronic component mounting substrate 1_2 having the same structure on the first layer electronic component mounting substrate 1. In the example of FIG. 13, on the conductive layer 50 of the first layer electronic component mounting substrate 1, the second layer electronic component mounting substrate 1_2 is soldered by reflowing the protruding portion 20a of the through electrode 20. It is electrically connected via bump B_20a. Although not shown, it is desirable that the first layer of the electronic component mounting substrate 1 and the second layer of the electronic component mounting substrate 1_2 are sealed with an organic layer.

(Example of a product on which a through-electrode substrate is mounted)
FIG. 14 is a diagram showing an example of a product on which the electronic component mounting substrate 1 according to the present embodiment can be mounted. The electronic component mounting substrate 1 according to this embodiment can be used in various products. For example, it is mounted on 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, and the like.

1 Electronic component mounting board 10 Board 11 First surface 12 Second surface 20 Through electrode 30 Electronic component

Claims (6)

A step of preparing a substrate having a first surface on the first side and a second surface on the second side opposite to the first side.
A step of forming a recess in the substrate from the first surface toward the second side, and
A step of forming an electrode containing solder at least partially inside the recess, and
A step of mounting an electronic component on the first surface and electrically connecting the electronic component to the electrode.
By scraping the substrate from the second surface side so that the electrode partially protrudes from the second surface to the second surface, the recess is penetrated from the first surface to the second surface. The electrode is processed into a through hole to be formed, and the electrode is located inside the through hole and partially protrudes from the second surface to the second side to become a through electrode containing at least a part of solder. A method for manufacturing a substrate on which an electronic component is mounted, which comprises a processing process. Step has a step of filling the solder paste into the interior of the recess, a method of manufacturing an electronic part mounting board according to claim 1 to form the electrode. The step of forming the electrode is
The step of forming the first conductive layer on the inner surface of the recess and
Wherein the first conductive layer, and a step of forming a second conductive layer containing the solder, the method of manufacturing the electronic component mounting board according to claim 1. The method for manufacturing an electronic component mounting substrate according to claim 3 , wherein the step of forming the electrode further includes a step of forming a third conductive layer on the second conductive layer. The electronic component has an exposed electrode 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 is described.
The step of adhering the electronic component to the first surface and
A step of forming an insulating layer having an insulating property on the first surface, on the electrode inside the recess, and on the electronic component.
The first portion located on the insulating layer, the second portion penetrating the insulating layer from the first portion to the electrode inside the recess, and the insulation from the first portion to the electrode of the electronic component. The method for manufacturing an electronic component mounting substrate according to any one of claims 1 to 4 , further comprising a step of forming a conductive layer having a third portion penetrating the layer. The method for manufacturing an electronic component mounting substrate according to any one of claims 1 to 5, wherein the substrate contains glass.

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