Structures and three-dimensional wiring structures equipped with these structures

Abstract

The present invention provides a structure that can mount electronic components with high bonding strength and high positional accuracy in any shape region including curved surfaces, and a three-dimensional wiring structure on which electronic components are mounted. [Solution] A structure 10 is provided in which an electronic component 70 is mounted in the recess 30, and a three-dimensional wiring structure 2 is provided in which an electronic component 70 is mounted in the structure 10, comprising: a resin body 20 on which wiring 50 is formed on the surface of the body 20; a recess 30 formed on the surface of the body 20, which is concave in shape and has a flat bottom surface 32 and an inner surface 34 surrounding the bottom surface 32; a terminal 60 formed on the bottom surface 32 and electrically connected to the wiring 50; and a fillet forming portion 40 formed in which the space of the recess 30 extends outward in a plan view of the recess 30.

Description

Technical Field

[0001] The present invention relates to a structure and a three-dimensional wiring structure including this structure.

Background Art

[0002] There is known a three-dimensional wiring structure in which wiring is formed on the surface of a resin structure and electronic components are mounted on this structure. Among them, there has been proposed a three-dimensional wiring structure in which a wiring groove and a recess deeper than the wiring groove are formed on the path of the wiring groove in a base substrate, and electronic components are mounted in the recess (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, electronic components are mounted on a flat base substrate. However, when mounting electronic components on a structure having various three-dimensional shapes including a curved surface that is not flat, problems such as tilting of the electronic components and positional deviation may occur, and the positional accuracy of the mounted electronic components may decrease. Further, in Patent Document 1, the land portion disposed at the bottom of the recess and the electrode terminals of the electronic components are connected with a conductive adhesive to mount the electronic components. However, when mounting the electronic components by soldering using a reflow apparatus for the purpose of improving the efficiency of mounting the electronic components, the melted solder may accumulate in the recess, an appropriate fillet may not be formed, and there is a risk that sufficient component bonding strength cannot be obtained.

[0005] Therefore, an object of the present invention is to provide a structure capable of mounting electronic components with high bonding strength and high positional accuracy in an arbitrary-shaped region including a curved surface, and a three-dimensional wiring structure in which electronic components are mounted on this structure. [Means for solving the problem]

[0006] The present invention encompasses the following embodiments. [1] A resin body with wiring formed on its surface, A concave shape formed on the surface of the main body, having a flat bottom surface and an inner surface surrounding the bottom surface, A terminal formed on the bottom surface and electrically connected to the wiring, In a plan view of the recess, the space of the recess extends outward to form a fillet-forming portion, Equipped with, A structure in which an electronic component is mounted in the recess.

[0007] [2] The structure according to [1], wherein a recess is formed in the curved surface region of the main body.

[0008] [3] The structure according to [2], wherein the recess is formed in the convex curved region of the main body.

[0009] [4] The structure according to any one of [1] to [3], wherein when the electronic component is placed in the recess and soldered to the terminal, the recess and the fillet forming portion are open and facing upward.

[0010] [5] The structure according to any one of [1] to [4], wherein the entire electronic component to be mounted is arranged inside the recess.

[0011] [6] In a plan view of the recess, the recess is formed to be larger by dimension C than the maximum tolerance dimension of the electronic component on which it is mounted. 50 μm ≤ C ≤ 200 μm A structure described in any of [1] to [5] that has the relationship.

[0012] [7] The inner surface is inclined outward by an angle θ with respect to a virtual surface perpendicular to the bottom surface, and is formed so as to widen as it progresses from the bottom surface to the upper opening. 2° ≤ θ ≤ 10° The structure according to any one of [1] to [6], having the relationship. The structure according to claim 1.

[0013] [8] In plan view of the recess, the fillet forming portion is formed to extend outward from the end of the recess by a dimension L. 200 μm ≤ L ≤ 1000 μm The structure according to any one of [1] to [7], having the relationship.

[0014] [9] The main body has a hollow structure formed of a planar member having a predetermined thickness with a first surface and a second surface which is the back surface thereof. The structure according to any one of [1] to [8], wherein the recess and the fillet forming portion are formed with the first surface being concave.

[0015]

[10] The main body has a first surface and a second surface which is the back surface thereof. A through hole is formed in the bottom surface of the recess where the first surface is concave, and the wiring formed on the second surface and the terminal formed on the bottom surface are electrically connected through a conductive member formed in the through hole. The structure according to any one of [1] to [9].

[0016]

[11] The structure according to any one of [1] to

[10] , and An electronic component mounted in the recess, and A three-dimensional wiring structure comprising.

Advantages of the Invention

[0017] According to one aspect of the present invention, it is possible to provide a structure capable of mounting an electronic component with high bonding strength and high positional accuracy in an arbitrarily shaped region including a curved surface, and a three-dimensional wiring structure in which an electronic component is mounted on this structure.

Brief Description of the Drawings

[0018] [Figure 1] It is a perspective view showing a structure according to the first embodiment of the present invention, and a three-dimensional wiring structure in which an electronic component is mounted on this structure. [Figure 2] It is a perspective view showing an example in which an electronic component is mounted in a recess formed in the main body of the structure and having fillet forming portions at both ends. [Figure 3] It is a perspective view showing a structure according to the second embodiment of the present invention, and a three-dimensional wiring structure in which an electronic component is mounted on this structure. [Figure 4] It is a perspective view schematically showing a first example of a recess having a fillet forming portion. [Figure 5A] It is a side cross-sectional view showing the cross-section A-A of FIG. 4. [Figure 5B] It is a side cross-sectional view schematically showing a state in which an electronic component is mounted in the recess shown in FIG. 5A. [Figure 6] It is a side cross-sectional view showing a cross-section at the same position as the cross-section A-A of FIG. 4, and schematically showing a state in which an electronic component is mounted in a second example of a recess having a fillet forming portion. [Figure 7] It is a perspective view schematically showing a third example of a recess having a fillet forming portion. [Figure 8A] It is a side cross-sectional view showing the cross-section B-B of FIG. 7. [Figure 8B] It is a side cross-sectional view schematically showing a state in which an electronic component is mounted in the recess shown in FIG. 8A. [Figure 9] It is a side cross-sectional view showing a cross-section at the same position as the cross-section B-B of FIG. 7, and schematically showing a state in which an electronic component is mounted in a fourth example of a recess having a fillet forming portion. [Figure 10] It is a side cross-sectional view showing a structure according to the third embodiment of the present invention, and a three-dimensional wiring structure in which an electronic component is mounted on this structure. [Figure 11] This is a side cross-sectional view showing a structure according to a fourth embodiment of the present invention, and a three-dimensional wiring structure on which electronic components are mounted. [Modes for carrying out the invention]

[0019] Embodiments for carrying out the present invention will be described below with reference to the drawings. In each drawing, corresponding components having the same function are denoted by the same reference numerals. For convenience, embodiments may be shown separately to facilitate explanation or understanding of key points, but partial substitution or combination of configurations shown in different embodiments is possible. In the embodiments described later, descriptions of matters common to the previously described embodiments will be omitted, and only the differences will be explained. In particular, similar effects and advantages due to similar configurations will not be mentioned sequentially for each embodiment. The size and positional relationships of components shown in the drawings may be exaggerated to clarify the explanation.

[0020] (Three-dimensional wiring structure according to the first embodiment) First, an overview of the three-dimensional wiring structure according to the first embodiment of the present invention will be described with reference to Figures 1 and 2. Figure 1 is a perspective view showing a structure according to the first embodiment of the present invention and a three-dimensional wiring structure on which electronic components are mounted. Figure 2 is a perspective view showing an example in which electronic components are mounted in recesses formed in the main body of the structure, which have fillet-forming portions at both ends.

[0021] The structure 10 according to this embodiment comprises a resin body 20 on which wiring 50 is formed on its surface. In plan view, the central part of the body 20 is curved, and in particular, a concave curved region is formed. The three-dimensional wiring structure 2 is composed of this structure 10 and a plurality of electronic components 70 mounted on the curved region of the body 20 of the structure 10. In this embodiment, an LED light source is mounted as the electronic component 70.

[0022] When mounting electronic components on such curved surfaces, problems such as tilting or misalignment of the components may occur, potentially reducing the positional accuracy of the mounted components. Furthermore, when mounting electronic components by soldering, the molten solder may flow along the curved surface, preventing the formation of proper fillets and resulting in unreliable component bonding strength.

[0023] However, in the three-dimensional wiring structure 2 according to this embodiment, a recess 30 is formed in the curved region, having a planar bottom surface 32 and an inner surface 34 surrounding the bottom surface. Furthermore, in a plan view of the recess 30, there is a fillet forming portion 40 formed by extending outward from the space of the recess 30. In this embodiment, two fillet forming portions 40 are formed, each extending outward from both sides of the recess 30. The wiring 50 formed on the surface of the main body extends into the interior of the fillet forming portion 40 and the recess 30 and is terminated with a terminal 60 (see, for example, Figure 4). Thus, a structure 10 having the recess 30, fillet forming portion 40, wiring 50 and terminal 60 is formed on the main body 20. Electronic components 70 are mounted on this structure 10 to form the three-dimensional wiring structure 2 according to this embodiment.

[0024] The electronic component 70, which is an LED light source, is composed of three LEDs of blue, green, and red colors, and has three component-side terminals 72 at each end. The structure 10 has three terminals 60 corresponding to the three component-side terminals 72 of the electronic component 70. When mounting the electronic component 70, it is placed on the flat bottom surface 32 of the recess 30, such that each component-side terminal 72 is positioned above the corresponding terminal 60. Solder paste is applied to the component-side terminals 72 and terminals 60 that are in contact with each other, and the structure 10 on which the electronic component 70 is placed is subjected to a reflow oven to perform soldering of the electronic component 70. Furthermore, in addition to solder paste, the component-side terminals 72 and 60 may also be joined with a conductive adhesive. In particular, if the main body 20 is made of a material with low heat resistance, it is preferable to join them with a conductive adhesive.

[0025] When joining the component terminals 72 and 60, there is a risk of component misalignment occurring during solder melting or before the conductive adhesive hardens. However, as will be explained in detail later, since the electronic component 70 is placed on the flat bottom surface 32 of the recess 30, problems such as tilting or misalignment of the electronic component 70 during reflow can be suppressed. Furthermore, during soldering, the molten solder flows into the fillet forming section 40, enabling good fillet formation and resulting in reliable component bonding strength. Similarly, when using a conductive adhesive, excess adhesive flows into the fillet forming section 40, enabling good fillet formation and resulting in reliable component bonding strength.

[0026] When forming a structure 10 having recesses 30, fillet-forming portions 40, wiring 50, and terminals 60 on the main body 20, it is preferable to use solder resist (SR) for the formation. This makes it possible to form fine pattern circuits. Furthermore, the solder resist maintains insulation between pattern circuits, protecting the pattern circuits from dust, heat, moisture, etc., over a long period of time.

[0027] The structure 10 according to this embodiment can be obtained, for example, by the following manufacturing method. To form a pattern circuit having the wiring 50 and terminals 60 as described above on a main body 20 having a recess 30, for example, a non-conductive metal complex is dispersed in a molding resin, which is the material of the main body 20. After forming a three-dimensional substrate using this molding resin, a laser beam is irradiated in line with the pattern circuit to generate metal nuclei, and then the pattern circuit can be formed by plating.

[0028] (Three-dimensional wiring structure according to the second embodiment) Next, an overview of the three-dimensional wiring structure according to the second embodiment of the present invention will be described with reference to Figure 3. Figure 3 is a perspective view showing the structure according to the second embodiment of the present invention and the three-dimensional wiring structure on which electronic components are mounted.

[0029] The three-dimensional wiring structure 2 according to the first embodiment described above has a concave curved surface region, while the three-dimensional wiring structure 2 according to the second embodiment differs in that it has a convex curved surface region. In other respects, it is basically the same as the first embodiment described above.

[0030] Multiple recesses 30, each having a planar bottom surface and an inner surface surrounding the bottom surface, and fillet-forming portions 40, formed by the space of the recess 30 extending outward in a plan view of the recess 30, are formed in the convex curved region of the main body 20 of the structure 10. Wiring 50 is formed on the surface of the main body 20, and the wiring 50 extends into the interior of the fillet-forming portions 40 and the recesses 30, and is terminated with terminals 60. Electronic components 70 are then mounted in the recesses 30 of the structure 10 to form a three-dimensional wiring structure 2.

[0031] (First example of a recess having a fillet-forming portion) Next, a first example of a recess having a fillet-forming portion will be described with reference to Figures 4, 5A, and 5B. Figure 4 is a schematic perspective view showing a first example of a recess having fillet-forming portions at both ends. Figure 5A is a side cross-sectional view showing cross-section AA of Figure 4. Figure 5B is a schematic side cross-sectional view showing an electronic component mounted in the recess shown in Figure 5A.

[0032] In the first example, the recess 30 has a planar bottom surface 32 and an inner surface 34 extending substantially perpendicular to the bottom surface 32. The recess 30 is formed by the bottom surface 32 being surrounded by the inner surface 34. The bottom surface 32 has a substantially rectangular shape, with the central portions of both sides in the longitudinal direction extending outward to form the bottom surface 42 of the fillet forming portion 40. In other words, the central portions of both ends in the longitudinal direction of the space of the recess 30 extend outward to form the fillet forming portion 40. The bottom surface 42 of the fillet forming portion 40 is formed on the same plane that extends continuously from the bottom surface 32 of the recess 30. Therefore, the recess 30 and the fillet forming portion 40 have the same depth D. The inner surface 44 of the fillet forming portion 40 also extends substantially perpendicular to the bottom surface 42.

[0033] In this embodiment, for simplicity, we show a case where there is one terminal 60 at each end of the recess 30. The wiring 50 formed on the surface of the main body 20 extends downward along the inner surface 44 of the fillet forming portion 40, and further extends through the bottom surface 42 of the fillet forming portion 40 to the area near the outside of the bottom surface 32 of the recess 30, where it terminates. The area of ​​the wiring 50 that terminates at the bottom surface 32 of the recess 30 becomes the terminal 60 which is electrically connected to the component-side terminal 72 of the electronic component 70.

[0034] A three-dimensional wiring structure 2 is formed by mounting electronic components 70 in recesses 30 having fillet forming portions 40, which are formed in multiple locations on the main body 20 of such a structure 10. To mount the electronic components 70, the electronic components 70 are placed on the planar bottom surface 32 of the recess 30 such that the positions of the component-side terminals 72 and the corresponding terminals 60 coincide. Solder paste is applied to the component-side terminals 72 and terminals 60 that are in contact with each other, and the structure 10 on which the electronic components 70 are mounted is subjected to a reflow oven to perform soldering of the electronic components 70. Alternatively, the component-side terminals 72 and terminals 60 may be joined with a conductive adhesive.

[0035] This results in a three-dimensional wiring structure 2 in which an electronic component 70 is mounted on the structure 10. The electronic component 70 is electrically connected to the wiring 50, and for example, the electronic component 70, which is an LED light source, can be made to emit light by power supplied through the wiring 50. Here, "electrically connected" refers to a state in which electricity flows between two conductive members, and the two conductive members may be in direct contact or connected via other conductive members.

[0036] In mounting the electronic component 70, even when the electronic component 70 is mounted on a concave or convex curved area of ​​the main body 20, the electronic component 70 is placed on the flat bottom surface 32 of the recess 30, and even if the bottom surface 32 is slightly inclined, the position of the electronic component 70 is maintained by the inner surface 34 of the recess 30, thus suppressing displacement of the electronic component 70. Furthermore, the molten solder during reflow flows smoothly from the bonding area of ​​the component-side terminals 72 and terminal 60 to the fillet forming section 40 without interference, so that an appropriate triangular fillet F is formed.

[0037] Figure 5B shows the three-dimensional wiring structure 2 formed in this manner. If the depth of the recess 30 and the fillet forming portion 40 is D, and the height of the electronic component 70 is H, then in the first example (hereinafter also referred to as Example 1), H > D They have a relationship.

[0038] In other words, in Example 1, a portion of the electronic component 70 is exposed above the recess 30 and the fillet forming portion 40. When the electronic component 70 is an LED light source, the light emitted from the electronic component 70 is not interfered with by the recess 30 or the fillet forming portion 40, enabling efficient illumination.

[0039] As described above, the curved region formed on the main body 20 may have a concave shape as in the first embodiment shown in Figure 1, a convex shape as in the second embodiment shown in Figure 2, or a shape having both concave and convex shapes. However, regardless of the type of curved region, by mounting the electronic component 70 in the recess 30 having a planar bottom surface 32 and an inner surface 34 surrounding it, misalignment can be suppressed and the electronic component 70 can be mounted with high positional accuracy. In particular, when mounting the electronic component 70 in a convex curved region as in the second embodiment shown in Figure 2, there is a risk of significant misalignment, but the planar bottom surface 32 and inner surface 34 of the recess 30 can maintain the position of the electronic component 70 during reflow, so the electronic component 70 can be mounted reliably.

[0040] Furthermore, the fillet forming portions 40 on both sides of the recess 30 allow for the formation of a good triangular fillet F during reflow, resulting in reliable component bonding strength. In addition, since at least the lower region of the electronic component 70 is positioned within the recess 30, the position of the electronic component is maintained and it can be protected. Therefore, even when including curved surfaces as shown in Figures 1 and 2, a structure can be provided that allows for the mounting of electronic components with high bonding strength and high positional accuracy.

[0041] Furthermore, in Example 1, when the electronic component 70 is placed in the recess 30 and soldered to the terminal 60, the recess 30 and the fillet forming portion 40 are open and facing upwards. Because the recess 30 and the fillet forming portion 40 are open and facing upwards during reflow, the electronic component 70 will not fall, nor will the molten solder flow down. Even if the bottom surface 32 is slightly inclined, the inner surface 34 can hold the position of the electronic component 70, and the fillet forming portion 40 can form a good triangular fillet F without the solder overflowing.

[0042] <Dimensions of the recess> The recess 30 is preferably sized to match the size of the electronic component 70 to be mounted. Specifically, it is preferable that, in a plan view of the recess 30, it is formed to be larger by dimension C than the maximum tolerance dimension of the electronic component 70 on which the recess 30 is mounted. More specifically, in a plan view of the recess 30, it is formed to be larger by dimension C than the maximum tolerance dimension of the electronic component 70 on which the recess 30 is mounted, 50 μm ≤ C ≤ 200 μm It is preferable that they have a relationship.

[0043] Considering the aging changes caused by the environment to which the electronic component 70 is exposed, including temperature, and the ease of actually placing the electronic component 70, it is preferable that the recess 30 be formed to be approximately 50 μm to 200 μm larger than the maximum tolerance dimension of the electronic component 70 to be mounted. With such dimensions, the electronic component 70 can be easily and reliably placed in the recess 30. At the same time, because the recess 30 is only slightly larger than the electronic component 70 to be mounted, even if the bottom surface 32 on which the electronic component 70 is placed is tilted during reflow, the inner surface 34 surrounding the bottom surface 32 can correctly hold the position of the electronic component 70, and positional displacement can be suppressed. Therefore, high component positioning accuracy can be obtained.

[0044] <Dimensions of the fillet formation area> The fillet forming portion 40 is preferably formed to be small enough so that the molten solder flows during reflow and forms a good triangular cross-section fillet F. Specifically, in a plan view of the recess 30, the fillet forming portion 40 is formed extending outward by a dimension L from each end of the recess 30. 200 μm ≤ L ≤ 1000 μm It is preferable that they have a relationship, 200 μm ≤ L ≤ 800 μm It is more preferable that the following relationship exists. Note that "end of recess 30" refers to the end of the recess 30 on the opening surface (upper surface).

[0045] By having dimension L within the above range, a good triangular cross-section fillet F can be reliably formed without solder overflow, and the size of the fillet-forming portion 40 can be minimized. As a result, more recesses 30 having fillet-forming portions 40 can be formed, and a larger area for wiring 50 can be obtained.

[0046] (Second example of a recess having a fillet-forming portion) Next, with reference to Figure 6, a second example of a recess having a fillet-forming portion will be described. Figure 6 is a cross-sectional view at the same position as cross-section AA in Figure 4, schematically showing a state in which an electronic component is mounted in the second example of a recess having a fillet-forming portion.

[0047] In Example 1 above, if the depth of the recess 30 and the fillet forming portion 40 is D, and the height of the electronic component 70 is H, then the relationship H > D was observed. However, in the second example, H ≤ D They differ in that they have the following relationship. The electronic component 70 may be an LED light source or other electronic device. Figure 6 shows the case where the height H of the electronic component 70 is smaller than the depth D of the recess 30 and the fillet forming portion 40, but the height H of the electronic component 70 may also be equal to the depth D of the recess 30 and the fillet forming portion 40.

[0048] As a result, in the second example, the entire electronic component 70 to be mounted is positioned inside the recess 30. Since the entire electronic component 70 is positioned inside the recess 30 during mounting, effective protection of the electronic component 70 becomes possible. For example, by filling the recess 30 on which the electronic component 70 is mounted with a resin material, the protection of the electronic component 70, terminals 60, wiring 50, etc. can be enhanced, and the insulation performance when wet can be improved.

[0049] (Third example of a recess having a fillet-forming portion) Next, a third example of a recess having a fillet-forming portion will be described with reference to Figures 7, 8A, and 8B. Figure 7 is a schematic perspective view showing a third example of a recess having a fillet-forming portion. Figure 8A is a side cross-sectional view showing cross section BB of Figure 7. Figure 8B is a schematic side cross-sectional view showing an electronic component mounted in the recess shown in Figure 8A.

[0050] In the first example of the recess described above, the inner surface 34 of the recess 30 extends approximately perpendicular to the bottom surface 32. However, in the third example shown in Figures 7, 8A, and 8B, the inner surface 34 extends at an angle θ outward with respect to a virtual plane perpendicular to the bottom surface 32. In other respects, it is basically the same as the first example shown in Figures 4, 5A, and 5B.

[0051] More specifically, in the third example, the inner surface 34 is formed to be inclined outward by an angle θ with respect to a virtual plane perpendicular to the bottom surface 32, and to widen as it proceeds from the bottom surface 32 towards the upper opening. In particular, the angle θ is 2 degrees ≦ θ ≦10 degrees It is preferable that they have a relationship.

[0052] The inner surface 34 is formed to widen as it moves from the bottom surface 32 towards the upper opening, and since the angle θ is within the range described above, the electronic component 70 can be easily and reliably placed in the recess 30, and high component positioning accuracy can be obtained. If the electronic component 70 is an LED light source, by using the inner surface 34, which is formed to widen as it moves from the bottom surface 32 towards the upper opening, as a reflective surface, the light emitted from the electronic component 70 can be emitted upward more effectively. In the third example as well, the inner surface 44 of the fillet forming section 40 extends approximately perpendicular to the bottom surface 42. However, it is not limited to this, and the inner surface 44 of the fillet forming section 40 can also be formed at an angle to the bottom surface 42.

[0053] The third example is the same as the first example except for the angle of the inner surface 34 of the recess 30, and therefore produces the same effects as described above. For example, even if the surface of the main body includes a curved surface as shown in Figures 1 and 2, the recess 30 and fillet forming section 40, which have a flat bottom surface 32 and an inner surface 34 surrounding it, allow for mounting of electronic components 70 with high bonding strength and high positional accuracy. Since the recess 30 and fillet forming section 40 open upwards during reflow, the electronic components 70 will not fall or molten solder will not flow down. Even if the bottom surface 32 is slightly inclined, the inner surface 34 can hold the position of the electronic components 70, and the fillet forming section 40 can form a good triangular cross-section fillet F without the solder overflowing.

[0054] In the third example as well, it is preferable that the size of the recess 30 is appropriate to the size of the electronic component 70 to be mounted. In Figure 8B, the electronic component 70 has a roughly rectangular parallelepiped shape, and it is preferable that, in a plan view of the recess 30 at the lower end of the narrowest inner surface 34, the recess 30 is formed to be 50 μm to 200 μm larger than the maximum tolerance dimension of the electronic component 70 on which it is mounted. With such dimensions, the electronic component 70 can be easily and reliably placed in the recess 30, and high component position accuracy can be obtained. Depending on the shape of the electronic component 70, it may also be preferable that the recess be formed to be 50 μm to 200 μm larger than the maximum tolerance dimension of the electronic component 70 at a position above the lower end of the inner surface 34.

[0055] Furthermore, in a plan view of the recess 30, the fillet forming portion 40 is formed extending outward from the end of the recess 30 by a dimension L. 200 μm ≤ L ≤ 1000 μm It is preferable that they have a relationship, 200 μm ≤ L ≤ 800 μm It is more preferable that the following relationship exists. Note that "end of recess 30" refers to the end of the recess 30 on the opening surface (upper surface). This ensures that a good triangular fillet F is formed reliably without solder overflowing, and the size of the fillet-forming portion 40 can be minimized. Therefore, more recesses 30 having fillet-forming portions 40 can be formed.

[0056] Furthermore, if the depth of the recess 30 and the fillet forming portion 40 is D, and the height of the electronic component 70 is H, then the relationship H > D holds. In Example 3, since a part of the electronic component 70 is exposed above the recess 30 and the fillet forming portion 40, if the electronic component 70 is an LED light source, the light emitted from the electronic component 70 can be efficiently illuminated without interference from the recess 30 or the fillet forming portion 40.

[0057] (Fourth example of a recess having a fillet-forming portion) Next, with reference to Figure 9, a fourth example of a recess having a fillet-forming portion will be described. Figure 9 is a cross-sectional view at the same position as cross-section BB in Figure 7, schematically showing a state in which an electronic component is mounted in the fourth example of a recess having a fillet-forming portion.

[0058] In Example 3 above, if the depth of the recess 30 and the fillet forming portion 40 is D, and the height of the electronic component 70 is H, then the relationship H > D was observed. However, in the second example, H ≤ D They differ in that they have the following relationship. The electronic component 70 may be an LED light source or other electronic device. Figure 9 shows the case where the height H of the electronic component 70 is smaller than the depth D of the recess 30 and the fillet forming portion 40, but the height H of the electronic component 70 may also be equal to the depth D of the recess 30 and the fillet forming portion 40.

[0059] As a result, in the fourth example, the entire electronic component 70 to be mounted is positioned inside the recess 30. Since the entire electronic component 70 is positioned inside the recess 30 during mounting, effective protection of the electronic component 70 becomes possible. For example, by filling the recess 30 on which the electronic component 70 is mounted with a resin material, the protection of the electronic component 70, terminals 60, wiring 50, etc. can be enhanced, and the insulation performance when wet can also be improved.

[0060] (Three-dimensional wiring structure according to the third embodiment) The above describes the first to fourth examples of recesses 30 having fillet-forming portions 40. Now, with reference to Figures 10 and 11, we will describe the three-dimensional wiring structures according to the third and fourth embodiments of the present invention. First, with reference to Figure 10, we will describe the three-dimensional wiring structure according to the third embodiment of the present invention. Figure 10 is a side cross-sectional view showing a structure according to the third embodiment of the present invention and a three-dimensional wiring structure on which electronic components are mounted.

[0061] In the three-dimensional wiring structure 2 according to the third embodiment, as is clear from Figure 10, the main body 20 has a hollow structure formed of a planar member with a predetermined thickness t having a first surface 20a and a second surface 20b which is the back surface thereof. The predetermined thickness t of the main body 20 can be exemplified as being in the range of 0.2 mm to 5.0 mm. The recess 30 and the fillet forming portion 40 are formed with the first surface 20a recessed outward.

[0062] In this embodiment, since the main body 20 has a hollow structure formed of a planar member, wiring can be formed on both the first surface 20a and the second surface 20b, thereby realizing a three-dimensional wiring structure 2 with a wider range of functions. Figure 10 shows that one electronic component 70 (left side of the drawing) is electrically connected to the wiring 50 formed on the first surface 20a, and the other electronic component 70 (right side of the drawing) is electrically connected to the wiring 50 formed on the second surface 20b.

[0063] In particular, a through-hole 80 is formed in the bottom surface 32 of the recess 30 (right side of the drawing) where the first surface 20a is concave. As a result, the wiring 50 formed on the second surface 20b and the terminal 60 formed on the bottom surface 32 are electrically connected via a conductive member 52 formed in the through-hole 80. Specific examples of the conductive member 52 include plating, conductive paste filling, and metal rod inserts.

[0064] Thus, a highly efficient three-dimensional wiring structure 2 is obtained, having an electronic component 70 mounted in a recess 30 having a terminal 60 connected to wiring 50 formed on the first surface 20a (left side of the drawing), and an electronic component 70 mounted in a recess 30 having a terminal 60 connected to wiring formed on the second surface 20b via a conductive member 52 formed in a through-hole 80 (right side of the drawing). Furthermore, for example, if all the wiring is formed only on the second surface 20b, and there is no wiring on the first surface 20a side, and the electronic component 70 is placed inside the recess 30, and the electronic component 70, the recess 30 and the fillet forming portion 40 are covered with a sealing member, a three-dimensional wiring structure 2 with dustproof and waterproof functions can be obtained. In particular, when the entire electronic component 70 to be mounted is placed inside the recess 30, as shown in Figure 6, the electronic component 70, the recess 30 and the fillet forming portion 40 can be sealed more easily. If the electronic component 70 is an LED light source, it can function as a light source by using a light-transmitting sealing member. For example, by incorporating a fluorescent material into a light-transmitting sealing material, it is possible to emit light of a desired color.

[0065] (Three-dimensional wiring structure according to the fourth embodiment) Next, with reference to Figure 11, a three-dimensional wiring structure according to the fourth embodiment of the present invention will be described. Figure 11 is a side cross-sectional view showing a structure according to the fourth embodiment of the present invention and a three-dimensional wiring structure on which electronic components are mounted.

[0066] In the three-dimensional wiring structure 2 according to the fourth embodiment, as is clear from Figure 11, the main body 20 has a solid structure. Even in the case of such a solid main body 20, a through-hole 80 is formed in the bottom surface 32 of the recess 30 (right side of the drawing) where the first surface 20a is concave, and a structure is obtained in which the wiring 50 formed on the second surface 20b and the terminal 60 formed on the bottom surface 32 are electrically connected via the through-hole 80.

[0067] Thus, even when the main body 20 has a solid structure, a highly efficient three-dimensional wiring structure 2 can be obtained, which includes an electronic component 70 mounted in a recess 30 having a terminal 60 connected to wiring 50 formed on the first surface 20a (left side of the drawing), and an electronic component 70 mounted in a recess 30 having a terminal 60 connected to wiring 50 formed on the second surface 20b via a conductive member 52 formed in a through-hole 80 (right side of the drawing). The main body 20 may be solid or hollow, but from the viewpoint of effective use of space, it is preferable to form the through-hole 80 in a hollow main body 20. Whether the main body 20 is solid or hollow, the above effects can be achieved in the same way.

[0068] (others) In the above embodiments and examples of the recess 30 and fillet forming portion 40, the fillet forming portion 40 extends outward from both sides of the recess 30 in a plan view of the recess 30, but this is not limited to this. Depending on the arrangement of the component-side terminals 72 of the electronic component 70, the fillet forming portion 40 can be extended in any other direction. Furthermore, it is possible that three or more fillet forming portions 40 are formed in a single recess 30. In any case, it is preferable that the fillet forming portion 40 is formed in a direction that allows the molten solder to flow smoothly without interference during reflow and to form an appropriate fillet.

[0069] (General) The structure 10 according to any of the above embodiments or examples includes a wiring 50, a resin body 20 on which the wiring 50 is formed on its surface, a recess 30 formed on the surface of the body 20 which has a concave shape and a planar bottom surface 32 and an inner surface 34 surrounding the bottom surface 32, a terminal 60 formed on the bottom surface 32 and electrically connected to the wiring 50, and a fillet forming portion 40 formed by extending outward from the space of the recess 30 in a plan view of the recess 30, and an electronic component 70 is mounted in the recess 30.

[0070] When mounting the electronic component 70 in the recess 30, the bottom surface 32 on which the terminals 60 are formed is flat, so high component position accuracy can be obtained, similar to when mounting on a flat substrate. Even if the bottom surface on which the electronic component 70 is placed is inclined during reflow, the inner surface 34 surrounding the bottom surface 32 can maintain the position of the electronic component 70, suppressing misalignment. Furthermore, the fillet forming portion 40 extending outward from the recess 30 allows for the formation of a good fillet F during reflow, resulting in highly reliable component bonding strength. In addition, since at least the lower region of the electronic component 70 is positioned within the recess 30, the position of the electronic component 70 is maintained, protecting the electronic component 70. As described above, a structure 10 can be provided that allows for the mounting of electronic components 70 with high bonding strength and high positional accuracy in any shape, including curved surfaces.

[0071] Furthermore, a three-dimensional wiring structure 2 comprising the above-described arbitrary structure 10 and an electronic component 70 mounted in the recess 30 of the structure 10 can achieve the above-described arbitrary effects.

[0072] While embodiments and modes of implementation of the present invention have been described, the disclosed content may change in the details of the configuration, and changes in the combination and order of elements in the embodiments and modes of implementation can be realized without departing from the claimed scope and spirit of the present invention. [Explanation of Symbols]

[0073] 2 Three-dimensional wiring structure 10 Structure 20 Main unit 20a First surface 20b Second face 30 recesses 32 Bottom 34 Inner surface 40 Fillet forming section 42 Bottom 44 Inner surface 50 Wiring 52 Conductive members 60 terminals 70 Electronic Components 72 Component-side terminals 80 Through Hole

Claims

1. A resin body with wiring formed on its surface, A concave shape formed on the surface of the main body, having a flat bottom surface and an inner surface surrounding the bottom surface, A terminal formed on the bottom surface and electrically connected to the wiring, In a plan view of the recess, the space of the recess extends outward to form a fillet-forming portion, Equipped with, A structure in which an electronic component is mounted in the recess.

2. The structure according to claim 1, wherein the recess is formed in the curved surface region of the main body.

3. The structure according to claim 2, wherein the recess is formed in the convex curved region of the main body.

4. The structure according to claim 1, wherein when the electronic component is placed in the recess and soldered to the terminal, the recess and the fillet forming portion are open and facing upward.

5. The structure according to claim 1, wherein the entire electronic component to be mounted is arranged inside the recess.

6. In a plan view of the recess, the recess is formed to be larger by dimension C than the maximum tolerance dimension of the electronic component on which it is mounted. 50μm≦C≦200μm The structure according to claim 1, having the relationship described above.

7. The inner surface is formed to be inclined outward by an angle θ with respect to a virtual plane perpendicular to the bottom surface, and to widen as it moves from the bottom surface towards the upper opening. 2 degrees ≦ θ ≦ 10 degrees The structure according to claim 1, having the relationship described above.

8. In a plan view of the recess, the fillet forming portion is formed extending outward from the end of the recess by a dimension L. 200μm≦L≦1000μm The structure according to claim 1, having the relationship described above.

9. The main body has a hollow structure formed of a planar member of a predetermined thickness having a first surface and a second surface which is the back surface thereof. The structure according to claim 1, wherein the recess and the fillet forming portion are formed with the first surface being concave.

10. The main body has a first surface and a second surface which is the back surface thereof. The structure according to claim 1, wherein a through-hole is formed in the bottom surface of the recess, which has a concave first surface, and the wiring formed on the second surface and the terminal formed on the bottom surface are electrically connected via a conductive member formed in the through-hole.

11. A structure according to any one of claims 1 to 10, The electronic component mounted in the recess, A three-dimensional wiring structure equipped with [a specific feature].

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