JP2011155169A - Electronic-component mounting structure, and method of manufacturing cavity substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic-component mounting structure which is compact and which is readily manufactured. <P>SOLUTION: The electronic-component mounting structure includes a cavity substrate 21, having a cavity part 24 for storing the first electronic component 13 on a main board 12; and the second electronic component 14 mounted on the cavity substrate 21. The cavity part 24 includes a base layer 23 directed toward the first electronic component 13; and a cavity layer 25, extending from the base layer 23 to the main board 12. The cavity layer 25 is formed in a shape such as to surround the cavity part 24, excluding a portion of the cavity part 24, when viewed from the main board 12. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an electronic component mounting structure including a cavity substrate that accommodates an electronic component on a main substrate, and a method for manufacturing the cavity substrate.

  In recent years, in order to further reduce the size and thickness of electronic devices, high-density mounting technology for mounting electronic components in a three-dimensional array has been required. As a conventional device using this type of mounting technology, for example, there is a semiconductor package described in Patent Document 1.

  The semiconductor package disclosed in Patent Document 1 includes a package substrate 2 on which a semiconductor element 1 is mounted and a cavity substrate 3 as shown in FIG. The package substrate 2 is mounted on the main substrate 4 by the first solder balls 5 with the semiconductor element 1 positioned on the upper side. The cavity substrate 3 includes a plate-like portion 3 a located above the package substrate 2 and a convex portion 3 b for connecting one side portion of the plate-like portion 3 a and the main substrate 4.

The convex portion 3 b is mounted on the main substrate 4 by the second solder ball 6. The semiconductor element 1 mounted on the cavity substrate 3 is positioned on the plate-like portion 3a. The plate-like portion 3 a is mounted on the package substrate 2 with solder balls 7.
In general, including a semiconductor package disclosed in Patent Document 1, when a semiconductor element is directly mounted on a substrate, a reinforcing resin (underfill resin) is filled between the semiconductor element and the substrate. The reason for filling the reinforcing resin in this way is to reinforce the solder bump between the semiconductor element and the substrate. That is, the thermal stress generated due to the difference in thermal expansion coefficient between the substrate and the semiconductor element can be relaxed by dispersing it in the reinforcing resin, so that the solder bump between the semiconductor element and the substrate is damaged by the thermal stress. Can be prevented.

JP 2009-206230 A

  The semiconductor package disclosed in Patent Document 1 has a problem that it has many manufacturing steps and is large. The reason for increasing the number of manufacturing steps is that the process of melting the solder is required twice. That is, after the solder between the package substrate 2 and the semiconductor element 1 is melted and solidified, a reinforcing resin is applied thereto, and then the solder between the package substrate 2 and the cavity substrate 3 must be melted. If the solder melting step is performed once, the reinforcing resin must be supplied from the outside of the package substrate 2 to the semiconductor element 1 after the solder is melted and solidified. In this case, the reinforcing resin is blocked by the solder balls 7 located around the semiconductor element 1, and the reinforcing resin cannot be supplied between the semiconductor element 1 and the package substrate 2.

  The main reason why the semiconductor package shown in Patent Document 1 is large is that it is necessary to form a wide clearance between the land of the solder ball 7 connecting the package substrate 2 and the cavity substrate 3 and the semiconductor element 1. It is. This clearance is formed widely in order to prevent the reinforcing resin from spreading on the package substrate 2 and flowing to the lands on the package substrate 2. In the semiconductor package shown in Patent Document 1, a cavity portion having a height capable of accommodating the package substrate 2 must be formed between the plate-like portion 3 a of the cavity substrate 3 and the main substrate 4. In other words, this semiconductor package has become large because the outer shape of the package substrate 2 is increased and the height of the cavity substrate 3 is increased.

  The present invention has been made to solve such problems, and it is an object of the present invention to provide an electronic component mounting structure and a cavity substrate manufacturing method that are easy to manufacture and miniaturized.

  In order to achieve this object, an electronic component mounting structure according to the present invention has a cavity portion that houses a first electronic component mounted on a main substrate, and the cavity substrate mounted on the main substrate; A second electronic component mounted on a side opposite to the first electronic component in the cavity portion, and the cavity portion is a base that faces the first electronic component from a side opposite to the main substrate. And a cavity layer extending from the base layer toward the main substrate and mounted on the main substrate. The cavity layer is formed by removing a part of the cavity portion when viewed from the main substrate side. And is formed in a shape surrounding the cavity.

  Further, the method for manufacturing a cavity substrate according to the present invention includes a step of forming a substrate base material such that a plurality of cavity parts for accommodating electronic components are arranged at equal intervals in two directions orthogonal to each other, and the substrate base material Cutting each of the cutting lines so that the cutting lines extend in two directions, and dividing them into individual cavity substrates, wherein at least one of the cutting lines extending in the two directions crosses the cavity portion. It is a method to do.

  According to the present invention, the inside of the cavity portion is exposed even when the first electronic component and the cavity substrate are mounted on the main substrate. The reinforcing resin can be supplied from this exposed portion. For this reason, the reinforcing resin can be sufficiently filled between the first electronic component and the main board after all the parts are mounted on the main board. In this mounting structure, since the reinforcing resin is sufficiently supplied in this way, the reliability of connection between the first electronic component and the main board is high.

Therefore, the electronic component mounting structure according to the present invention can melt and solidify all the solders at one time while adopting a configuration capable of sufficiently filling the reinforcing resin. Manufacturing is easier than this.
Further, since it is not necessary to form a space for preventing the reinforcing resin from flowing into the land between the electronic component mounting structure cavity substrate and the first electronic component, the first electronic component and the cavity substrate The clearance between them can be formed narrow.

In addition, since the first electronic component can be directly mounted on the main substrate, the base portion of the cavity substrate can be formed so as to be positioned close to the main substrate. As a result, according to the present invention, it is possible to provide a mounting structure for an electronic component that is smaller than the semiconductor package described in Patent Document 1.
According to the method for manufacturing a cavity substrate according to the present invention, it is possible to easily manufacture a cavity substrate having a cavity layer having a shape surrounding the cavity portion except for a part of the cavity portion.

It is a top view of the three-dimensional mounting structure using a U-shaped cavity board | substrate. 1 is a cross-sectional view of a three-dimensional mounting structure using a U-shaped cavity substrate, which is a cross-sectional view taken along the line II-II in FIG. It is a figure which shows the cavity substrate whose shape of a cavity layer is a U-shape, The figure (A) is sectional drawing, The figure (B) is a bottom view. In FIG. 5B, the fracture position in FIG. It is sectional drawing for demonstrating the manufacturing method of the three-dimensional mounting structure using a cavity board | substrate, The figure shows the state at the time of mounting. It is sectional drawing for demonstrating the manufacturing method of the three-dimensional mounting structure using a cavity board | substrate, The figure shows the state after a reflow process. It is sectional drawing which shows the other Example of the three-dimensional mounting structure using a U-shaped cavity board | substrate. It is sectional drawing which shows the three-dimensional mounting structure which has a some cavity part. It is a figure which shows the cavity board | substrate with the shape of a cavity layer, the figure (A) is sectional drawing, and the figure (B) is a bottom view. In FIG. 5B, the fracture position in FIG. FIG. 3A is a cross-sectional view of a cavity substrate having a cross-shaped cavity layer, and FIG. In FIG. 5B, the fracture position in FIG. The figure which shows the cavity board | substrate whose shape of a cavity layer is a T-shape, The figure (A) is sectional drawing, The figure (B) is a bottom view. In FIG. 5B, the fracture position in FIG. The cavity layer is a X-shaped cavity substrate, in which FIG. (A) is a cross-sectional view and FIG. (B) is a bottom view. In FIG. 5B, the fracture position in FIG. It is a top view of the three-dimensional mounting structure which apply | coated reinforcement resin from the both sides of the electronic component mounted in the cavity part. It is sectional drawing of the three-dimensional mounting structure which apply | coated reinforcement resin from the both sides of the electronic component mounted in the cavity part, The figure is the XIII-XIII sectional view taken on the line in FIG. It is sectional drawing of the three-dimensional mounting structure which apply | coated reinforcement resin from the both sides of the electronic component mounted in the cavity part, The figure is the XIV-XIV sectional view taken on the line in FIG. It is a figure which shows the cavity board | substrate whose shape of a cavity layer is D shape, The figure (A) is sectional drawing, The figure (B) is a bottom view. In FIG. 5B, the fracture position in FIG. It is sectional drawing which shows the three-dimensional mounting structure using a several cavity board | substrate. These are sectional drawings which show an example of the mounting structure which covers the whole circumference | surroundings of the 1st electronic component mounted on the main board with a cavity board | substrate. It is a figure which shows the relationship between the shape of a cavity layer, the number of connection terminals, the cavity part area which can be mounted, and a cavity board | substrate size. FIG. 4A shows the case where the shape of the cavity layer is a square shape, FIG. 4B shows the case where the shape of the cavity layer is a U shape, and FIG. FIGS. 3D and 3E show the case where the shape of the cavity layer is a D-shape. It is a perspective view for demonstrating the manufacturing method of the cavity substrate whose shape of a cavity layer is a U-shape. It is a perspective view for demonstrating the manufacturing method of the cavity board | substrate whose shape of a cavity layer is H shape. It is a perspective view for demonstrating the manufacturing method of the cavity board | substrate whose shape of a cavity layer is a cross shape. It is a perspective view for demonstrating the manufacturing method of the cavity board | substrate whose shape of a cavity layer is a T shape. It is a perspective view for demonstrating the manufacturing method of the cavity board | substrate whose shape of a cavity layer is D shape. It is a perspective view for demonstrating the manufacturing method of the cavity board | substrate whose shape of a cavity layer is x character type. It is sectional drawing which shows the conventional mounting structure.

(First embodiment)
An embodiment of the electronic component mounting structure and the cavity substrate manufacturing method according to the present invention will be described below in detail with reference to FIGS. In this embodiment, the electronic component mounting structure according to the present invention is simply called a three-dimensional mounting structure.
The three-dimensional mounting structure 11 shown in FIG. 1 and FIG. 2 is mounted so that a first electronic component 13 and a second electronic component 14 are arranged in a vertical direction on a main board 12 as a main board in the present invention. This is the mounting structure.

  The first electronic component 13 is an active component such as a BGA (Ball Grid Array), a CSP (Chip Size Package), a WLCSP (Wafer Level Chip Size Package), a bare chip, or a passive component such as a chip capacitor, a chip resistor, or a chip coil. It is a part. The first electronic component 13 is directly mounted on the main board 12 with a connection material such as a solder bump 16. A reinforcing resin (underfill resin) 17 is filled between the first electronic component 13 and the main board 12.

  The second electronic component 14 includes an electronic component 18 composed of a package such as CSP, BGA, QFP (Quad Flat Package), SOP (Small Outline Package), TSOP (thin small out-line package), a chip capacitor, and a chip. Electronic components 19 such as resistors and chip coils are used. The second electronic component 14 is mounted on a cavity substrate 21 described later with a connecting material such as a solder bump 22 and is supported by the main board 12 via the cavity substrate 21.

As shown in FIGS. 1 to 3, the cavity substrate 21 includes a base layer 23 that faces the first electronic component 13 from the side opposite to the main board 12, and a cavity portion 24 ( And a cavity layer 25 for forming (see FIGS. 2 and 3).
The cavity substrate 21 may be made of any base material such as a resin substrate, a ceramic substrate, or a Si substrate. That is, in this specification, the sectional view of the cavity substrate 21 is hatched with resin, but the material of the cavity substrate 21 is not limited to the resin material.

The base layer 23 is formed in a square plate shape in plan view. As shown in FIG. 2, the base layer 23 is separated from the first electronic component 13 with a predetermined clearance.
The cavity layer 25 is formed to extend from the base layer 23 toward the main board 12, and is mounted on the main board 12 with a connection material such as a solder bump 26. As shown in FIG. 2, the reinforcing resin 17 is filled between the cavity layer 25 and the main board 12.

  As shown in FIG. 3B, the cavity layer 25 according to this embodiment is formed in a U shape when viewed from the main board 12 side. In other words, the cavity layer 25 is formed in a shape surrounding the cavity portion 24 except for a part (one side portion) of the cavity portion 24 when viewed from the main board 12 side. The cavity part 24 formed inside the cavity layer 25 is communicated with a space outside the cavity part through an opening 24a not surrounded by the cavity layer 25. On the lower surface of the cavity layer 25, that is, the surface facing the main board 12, a large number of solder bumps 26 are provided over the entire formation range.

  As shown in FIGS. 1 and 2, the first electronic component 13 shown in this embodiment has a protruding portion 13 a that protrudes outside the cavity portion 24 from the opening 24 a. The reason why a part of the first electronic component 13 is protruded from the cavity portion 24 is to make it possible to visually recognize the position where the reinforcing resin 17 is permeated. Electronic parts such as BGA and CSP that require the reinforcing resin 17 may be directly coated with the reinforcing resin 17 by projecting one end of the electronic component from the opening 24a or positioning it in the vicinity of the opening 24a even if it does not protrude. As a result, the connection reliability of the solder bumps 16 is increased.

Next, the procedure for mounting the first and second electronic components 13 and 14 on the main board 12 by the three-dimensional mounting structure 11 according to this embodiment will be described with reference to FIGS.
First, as shown in FIG. 4, the solder paste 27 is printed on the main board 12 and the first electronic component 13 is mounted. Next, the cavity substrate 21 is mounted at a predetermined position around the first electronic component 13. The cavity substrate 21 is preferably formed in a predetermined shape in advance, and the second electronic component 14 (electronic components 18 and 19) is mounted on the base layer 23.

  Thereafter, the cavity substrate 21 is mounted on the main board 12. At this time, the cavity substrate 21 is placed on the first electronic component 13 so that the first electronic component 13 is accommodated in the cavity portion 24 of the cavity substrate 21. After mounting the first electronic component 13 and the cavity substrate 21 on the main board 12 in this way, they are collectively supplied to a reflow furnace (not shown) to melt and solidify the solder bumps 16, 22, and 26. .

  As a result, as shown in FIG. 5, the first electronic component 13 and the cavity substrate 21 are connected to the main board 12. Thereafter, for the resin to which the reinforcing resin 17 is applied, the reinforcing resin 17 is interposed between the main board 12 and the first electronic component 13 from the opening 24a of the cavity portion 24 as indicated by an arrow A in FIG. Infiltrate and fill. Further, the reinforcing resin 17 is also filled between the cavity layer 25 of the cavity substrate 21 and the main board 12.

  Therefore, in the three-dimensional mounting structure 11 according to this embodiment, the reinforcing resin 17 can be sufficiently filled between the main board 12 and the first electronic component 13 after all the electronic components are mounted on the main board 12. it can. As a result, according to the three-dimensional mounting structure 11, all the solder can be melted and solidified in one reflow process while adopting a configuration capable of sufficiently filling the reinforcing resin 17. As compared with the semiconductor package shown in FIG.

  In the three-dimensional mounting structure 11, a space is formed between the cavity substrate 21 and the first electronic component 13 to prevent the reinforcing resin 17 from flowing to the solder bump connection land (not shown). There is no need. For this reason, according to this three-dimensional mounting structure 11, the clearance between the first electronic component 13 and the cavity layer 25 can be formed narrow. In addition, since the first electronic component 13 can be directly mounted on the main board 12, the cavity substrate 21 can be formed so that the base layer 23 is positioned close to the main board 12. As a result, according to this embodiment, it is possible to provide a three-dimensional mounting structure that is smaller than the semiconductor package described in Patent Document 1.

In this embodiment, a reinforcing resin 17 is filled between the main board 12 and the first electronic component 13. For this reason, according to this embodiment, it is possible to provide a three-dimensional mounting structure with high connection reliability between the main board 12 and the first electronic component 13.
In the three-dimensional mounting structure 11 according to this embodiment, the base layer 23 of the cavity substrate 21 is separated from the first electronic component 13. For this reason, even if the difference in thermal expansion coefficient between the main board 12 and the cavity substrate 21 is large, no warp is caused by thermal stress after reflow. Therefore, according to this embodiment, it is possible to provide a three-dimensional mounting structure in which mounting defects of the first electronic component 13 and the cavity substrate 21 are unlikely to occur.

The first electronic component 13 according to this embodiment has a protruding portion 13 a that protrudes outside the cavity portion 24 from the opening portion 24 a of the cavity portion 24. For this reason, according to this embodiment, the position where the reinforcing resin 17 is permeated can be visually confirmed, and the reinforcing resin supply nozzle can be brought close to this position, so that the reinforcing resin 17 can be reliably applied. .
As shown in FIG. 6, the first electronic component 13 can be accommodated entirely in the cavity portion 24. In this case, as indicated by an arrow A in the figure, the reinforcing resin 17 is permeated little by little between the main board 12 and the first electronic component 13 through the opening 24a, as in the case described above. The reinforcing resin 17 can be filled.

(Second embodiment)
The cavity substrate can be provided with a plurality of cavity portions as shown in FIGS. In these drawings, the same or equivalent members as those described with reference to FIGS. 1 to 6 are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

  The cavity substrate 21 shown in FIG. 7 is provided with a cavity layer 25 at the center in the left-right direction of the base layer 23 in the figure, and cavity portions 24 are formed on both sides of the cavity layer 25, respectively. As shown in FIG. 8B, the cavity layer 25 is formed in an H shape when viewed from the main board 12 side.

That is, also in this embodiment, the cavity layer 25 is formed in a shape surrounding the cavity part 24 except for a part (one side part) of the cavity part 24 when viewed from the main board 12 side. The two cavities 24 shown in this embodiment are communicated with spaces outside the cavities via openings 24a not surrounded by the cavity layer 25, respectively.
In this way, the cavity substrate 21 having the plurality of cavity portions 24 can be formed as shown in FIGS.

The cavity layer 25 of the cavity substrate 21 shown in FIG. 9 is formed in a cross shape when viewed from the main board 12 side. Four cavity portions 24 are formed in the cavity substrate 21 shown in FIG.
The cavity layer 25 of the cavity substrate 21 shown in FIG. 10 is formed in a T shape when viewed from the main board 12 side.
The cavity layer 25 of the cavity substrate 21 shown in FIG. 11 is formed in an X shape when viewed from the main board 12 side.

(Third embodiment)
As shown in FIGS. 12 to 15, the three-dimensional mounting structure according to the present invention can take a configuration in which both end portions of the first electronic component protrude from the cavity portion. In these drawings, the same or equivalent members as those described with reference to FIGS. 1 to 11 are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

  As shown in FIG. 15B, the cavity layer 25 of the cavity substrate 21 according to this embodiment is formed in a square shape when viewed from the main board 12 side. That is, the cavity part 24 formed in the cavity substrate 21 communicates with the space outside the cavity part through the openings 24a and 24a formed at both ends thereof.

  As shown in FIG. 12 and FIG. 13, one end and the other end of the first electronic component 13 according to this embodiment protrude from the two openings 24a and 24a of the cavity 24 to the outside of the cavity, respectively. Yes. For this reason, the operation | work which apply | coats the reinforcement resin 17 can be easily performed, making the nozzle for reinforcement resin supply approach the said 2 protrusion part, and visually checking. If it is desired to reduce the mounting area as much as possible, the entire first electronic component 13 may be accommodated inside the formation range of the cavity substrate 21. In this case, when the reinforcing resin 17 is applied, the reinforcing resin 17 is infiltrated little by little through the opening 24 a and filled between the first electronic component 13 and the main board 12.

(Fourth embodiment)
As shown in FIG. 16, the three-dimensional mounting structure 11 according to the present invention can be configured using a plurality of cavity substrates. In FIG. 16, the same or equivalent members as described with reference to FIGS. 1 to 15 are given the same reference numerals, and detailed description thereof is omitted as appropriate.

  A three-dimensional mounting structure 11 shown in FIG. 16 includes a first cavity substrate 31 and a second cavity substrate 32. The first cavity substrate 31 has a plurality of cavity portions 24 and is the same as the cavity substrate 21 described with reference to FIGS. 8 to 11 in the second embodiment described above. The second cavity substrate 32 is the same as the cavity substrate 21 described with reference to FIG. 3 in the first embodiment described above.

  In the three-dimensional mounting structure 11 according to this embodiment, the first electronic component 13 is accommodated in the cavity space 33 formed by arranging the first and second cavity substrates 31 and 32 so as to be adjacent to each other. Yes. In the cavity space 33, the opening 24a of the cavity 24 formed in the first cavity substrate 21 and the opening 24a of the cavity 24 formed in the second cavity substrate 21 are opposed to each other. Is formed by.

  The relatively large first electronic component 13 is accommodated in the cavity space 33 formed of a relatively wide space. In order to fill the reinforcing resin 17 between the large first electronic component 13 and the main board 12, as shown by an arrow B in FIG. Can be carried out through the gap 34 formed between the two.

  Since the cavity substrate 21 and the first and second cavity substrates 31 and 32 shown in the first to fourth embodiments described above are formed in a shape in which a part of the cavity portion 24 is cut out, As will be described later, the mounting area can be reduced. The reason for this will be described with reference to FIGS. FIG. 17 is a cross-sectional view showing an example of a mounting structure in which the entire periphery of the first electronic component 13 mounted on the main board 12 is covered with a cavity substrate. In the figure, members identical or equivalent to those described with reference to FIGS. 1 to 15 are given the same reference numerals, and detailed description thereof is omitted as appropriate.

  The cavity layer 25 of the cavity substrate 21 shown in FIG. 17 is formed in a square shape when viewed from the main board 12 side. Normally, when the entire periphery of the first electronic component 13 mounted on the main board 12 is covered with the cavity layer 25 of the cavity substrate 21, the processing accuracy of the cavity layer 25, the SR accuracy of the cavity substrate 21 and the main board 12, and surface mounting Considering the mounting accuracy at the time, as shown in FIG. 17, the clearance a between the first electronic component 13 and the cavity wall (the inner wall of the cavity portion 24) and the clearance b between the cavity wall and the solder bump land are required. Become. Since the total value of the clearance a and the clearance b is 1 mm or more in some cases, the outer shape of the cavity substrate 21 becomes larger than necessary. However, by forming the cavity layer 25 in a U-shape, T-shape, D-shape, or the like, it is possible to reduce the clearance that is wasted space.

  FIG. 18 shows the number of connection terminals, the area of the cavity portion 24 that can be mounted, and the mounting area of the cavity substrate 21 when the shape of the cavity layer 25 is a square, U, T, or D shape. This shows a comparative example. In FIG. 18, the region where the connection terminal is provided is indicated by left-down hatching, and the mountable cavity portion 24 is indicated by right-down hatching. The clearance part is not hatched.

In FIG. 18, one block has a size of 0.4 mm on one side. FIG. 18 is drawn to show a state when the connection terminals are arranged at a pitch of 0.4 mm. The cavity area that can be mounted and the connection terminal are separated by 1.2 mm (3 blocks) in order to ensure the above-described clearance. In addition, the number of connection terminals is estimated on the assumption that Min 140 pins are secured.
The results of this trial calculation are shown in Table 1 below. From the result of this trial calculation, the size of the cavity substrate 21 (mounting) is ensured for the U-shape, T-shape, and D-shape, while ensuring the same number of connection terminals and mountable cavity portion 24 area as compared to the square-shape. It is shown that (area) can be reduced by about 10 to 25%.

このため、上述した各実施例に示すように、キャビティ基板２１のキャビティ層２５をメインボード１２側から見てコの字、Ｔ字、ニの字のうちいずれか一つの形状に形成することによって、キャビティ層２５がロ字型である場合に較べて、キャビティ基板２１の外形（実装面積）を小さく形成することができる。また、キャビティ層２５の形状がH字型、X字型、十字型の場合であっても、キャビティ部２４の開口部２４ａには前記クリアランス部分が不要であるから、上記同様にキャビティ基板２１の外形を小さく形成することができる。

For this reason, as shown in the above-described embodiments, the cavity layer 25 of the cavity substrate 21 is formed in any one of a U shape, a T shape, and a D shape when viewed from the main board 12 side. The outer shape (mounting area) of the cavity substrate 21 can be made smaller than when the cavity layer 25 has a square shape. Even if the cavity layer 25 is H-shaped, X-shaped, or cross-shaped, the opening 24a of the cavity portion 24 does not require the clearance portion. The outer shape can be formed small.

Next, a method for manufacturing the cavity substrate 21 shown in each of the above embodiments will be described in detail with reference to FIGS. In these drawings, members that are the same as or equivalent to those described with reference to FIGS. 1 to 15 are given the same reference numerals, and detailed descriptions thereof are omitted as appropriate.
In order to manufacture the cavity substrate 21 shown in each of the above-described embodiments, first, as shown in FIG. 19, for example, a substrate base material 41 is manufactured using a known technique. A plurality of cavity portions 24 for storing electronic components are formed on the substrate base material 41 so as to be arranged at equal intervals in two directions orthogonal to each other. These two directions are directions parallel to two mutually orthogonal sides of the substrate base material 41 formed so as to be a quadrangle in plan view.

  Next, the substrate base material 41 is cut by a dicer (not shown) as described later. This dicer has a structure in which the substrate base material 41 is cut while being translated along a predetermined dicing line (cutting line). In order to cut the substrate base material 41 with this dicer, the dicer is moved in parallel along the first cutting line 42 and the second cutting line 43 as shown in FIGS.

Of the cavity substrates 21 shown in the above-described embodiments, in order to manufacture the cavity substrate 21 in which the cavity layer 25 is formed in a U shape when viewed from the main board 12 side, as shown in FIG. 1. Position the second cutting lines 42, 43.
A first cutting line 42 shown in FIG. 19 extends only between the cavity portions 24. Further, the second cutting line 43 extends in a direction orthogonal to the first cutting line 42 and crosses the cavity portion 24. The position where the second cutting line 43 crosses the cavity portion 24 is one side portion of the cavity portion 24 and is a position overlapping the inner wall surface 24b in plan view.

The substrate base material 41 is divided into a plurality of cavity substrates 21 having a U-shaped cavity layer 25 by being cut along the first and second cutting lines 42 and 43.
In order to form the cavity substrate 21 in which the cavity layer 25 has an H shape in plan view, the first and second cutting lines 43 are positioned as shown in FIG. A first cutting line 42 shown in FIG. 20 is positioned so as to cross the central portion of the cavity portion 24. The second cutting line 43 is positioned so as to extend in a direction orthogonal to the first cutting line 42 and pass only between the cavity portions 24.

  In order to form the cavity substrate 21 in which the cavity layer 25 has a cross shape in plan view, the first and second cutting lines 42 and 43 are positioned as shown in FIG. A first cutting line 42 shown in FIG. 21 is positioned so as to cross the central portion of the cavity portion 24. Further, the second cutting line 43 extends in a direction orthogonal to the first cutting line 42 and is positioned so as to cross the central portion of the cavity portion 24.

  In order to form the cavity substrate 21 in which the cavity layer 25 has a T shape in plan view, the first and second cutting lines 42 and 43 are positioned as shown in FIG. A first cutting line 42 shown in FIG. 22 is located on one side of the cavity 24 and overlaps the inner wall surface 24b in plan view. Further, the second cutting line 43 extends in a direction orthogonal to the first cutting line 42 and is positioned so as to cross the central portion of the cavity portion 24.

  In order to form the cavity substrate 21 in which the cavity layer 25 has a B shape in plan view, the first and second cutting lines 42 and 43 are positioned as shown in FIG. The first cutting line 42 shown in FIG. 23 is positioned so as to pass only between the cavity portions 24. Further, the second cutting line 43 extends in a direction orthogonal to the first cutting line 42, and is a two side portions of the cavity portion 24 facing each other, and has a position overlapping the inner wall surface 24b in plan view. It is positioned to pass.

  In order to form the cavity substrate 21 in which the cavity layer 25 has an X shape in plan view, the first and second cutting lines 42 and 43 are positioned as shown in FIG. The first cutting line 42 shown in FIG. 24 is positioned on one of the two diagonal lines of the cavity portion 24. Further, the second cutting line 43 is positioned on the other diagonal line of the other cavity portion 24 that is not crossed by the first cutting line 42.

  In cutting the substrate base material 41 as described above, the wiring (not shown) of the cavity substrate 21 and the positions of the first and second 42 and the cutting line 43 are appropriately determined in advance in consideration of the cutting position. It is necessary to design. More specifically, the area around which the wiring is routed is formed to be sufficiently separated from the first and second cutting lines 42 and 43. When dicing a special cavity substrate 21 as shown in FIG. 19 to FIG. 24, it is desirable to cut with high precision aiming at the center between the inner wall surface 24b of the cavity portion 24 and the cavity portion 24. There is a concern that the cutting position may be slightly shifted depending on the positioning accuracy of the nozzle and the accuracy of the dicer.

  As a method for solving this problem, it is desirable to use a dicer blade having a sufficiently large blade width (blade width). In this case, it is desirable that the wiring routing area be separated from the first and second cutting lines 43 in consideration of the blade width during dicing. Also, it is desirable to secure a sufficient area for the line widths of the first and second cutting lines 42 and 43.

  As described above, according to the manufacturing method of manufacturing the cavity substrate 21 by dividing the substrate base material 41, the cavity substrate 21 having the cavity layer 25 having a shape surrounding the cavity portion 24 except for a part of the cavity portion 24 can be simplified. Can be manufactured.

  In each of the above-described embodiments, the example in which the reinforcing resin 17 is applied between the main board 12 and the first electronic component 13 has been described. However, in order to reduce the mounting area without applying the reinforcing resin 17. Only the three-dimensional mounting structure 11 may be used.

A specific example of the above-described three-dimensional mounting structure 11 and manufacturing method will be described. First, SnAgCu lead-free solder paste is printed on the main board 12 at a predetermined position. Subsequently, a 6 mm square WLCSP having a solder bump terminal of 0.3 mm thickness and 0.4 mm pitch is mounted on the main board 12 using a mounter.
Subsequently, the cavity substrate 21 is mounted at a predetermined position around the WLCSP. Here, it is assumed that the cavity substrate 21 has a size of 10 mm square, and the cavity layer 25 is processed into a U shape so as to have a cavity of 8 × 7 mm. A clearance of 1 mm is formed between the inner wall surface 24b of the cavity portion 24 and the WLCSP.

  The cavity portion 24 is formed with a depth of 0.4 mm so as not to contact the WLCSP. The total thickness of the base layer 23 and the cavity layer 25 of the cavity substrate 21 is about 0.65 mm. The main board 12 mounted with the first electronic component 13 and the cavity substrate 21 (with the second electronic component 14 mounted) is poured into a reflow furnace at a maximum of 250 ° C. to melt the solder, Connect each one.

Finally, the reinforcing resin 17 is applied to the completed three-dimensional mounting structure. Since the reinforcing resin 17 is first filled in the WLCSP, it is applied little by little to one side (6 mm width) exposed from the opening 24 a of the cavity substrate 21. The nozzle for applying the reinforcing resin 17 is moved away from the WLCSP by about 0.1 to 0.5 mm and applied directly to the WLCSP.
After the reinforcing resin 17 is sufficiently applied to the solder connection portion of the WLCSP, the reinforcing resin 17 is applied to the entire cavity substrate 21. When the reinforcing resin 17 having a small WLCSP size or high permeability is used, the reinforcing resin 17 may be applied to the WLCSP and the cavity substrate 21 at once. It should be noted that the various design values of the components described here are desirably set to be optimal each time according to the target three-dimensional mounting structure 11.

  On the other hand, it is desirable that the dicer used in the process of manufacturing the cavity substrate 21 has a sufficiently thick blade width (blade width) such as 0.3 to 0.8 mm. In this case, it is desirable that the wiring routing area be separated from the first and second cutting lines 43 by at least about 0.2 to 0.5 mm on one side in consideration of the dicing blade width. Also, it is desirable to secure a sufficient area of the dicing line width (the line width of the first and second cutting lines 43) of about 0.3 to 0.8 mm.

  DESCRIPTION OF SYMBOLS 12 ... Main board, 13 ... 1st electronic component, 14 ... 2nd electronic component, 21 ... Cavity board | substrate, 23 ... Base layer, 24 ... Cavity part, 24a ... Opening part, 25 ... Cavity layer, 41 ... Substrate mother Wood.

Claims (6)

A cavity part for accommodating a first electronic component mounted on the main board, and a cavity board mounted on the main board;
A second electronic component mounted on the opposite side of the cavity portion from the first electronic component;
The cavity portion includes a base layer facing the first electronic component from a side opposite to the main substrate,
A cavity layer extending from the base layer toward the main substrate and mounted on the main substrate;
The electronic component mounting structure, wherein the cavity layer is formed in a shape surrounding the cavity portion except for a part of the cavity portion when viewed from the main substrate side.   2. The electronic component mounting structure according to claim 1, wherein a reinforcing resin is filled between the main substrate and the first electronic component.   3. The electronic component mounting structure according to claim 1, wherein a base layer of the cavity substrate is separated from the first electronic component. 4.   The electronic component mounting structure according to any one of claims 1 to 3, wherein the first electronic component is disposed outside the cavity portion from an opening portion not surrounded by the cavity layer in the cavity portion. A mounting structure for an electronic component, characterized in that it has a protruding portion that protrudes from the surface.   5. The electronic component mounting structure according to claim 1, wherein the cavity layer has a U-shape, a D-shape, an H-shape, an X-shape, a T-shape, as viewed from the main substrate side. An electronic component mounting structure, wherein the electronic component is formed in one of a letter shape and a cross shape. Forming a substrate base material so that a plurality of cavity parts for accommodating electronic components are arranged at equal intervals in two directions orthogonal to each other;
Cutting the substrate base material so that a cutting line extends in two directions and dividing it into individual cavity substrates,
A method for manufacturing a cavity substrate, wherein at least one of the cutting lines extending in the two directions crosses the cavity portion.

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