Electronic component mounting substrate, electric device, and light emitting device

Abstract

An electronic component mounting substrate (A) of one embodiment has a plate-like base (1), wherein a first surface (1a) of the base (1) is inclined relative to a second surface (1b) opposite to the first surface (1a), and when one side of the base (1) bisected in the inclination direction is a low-position portion (1L) and the other side is a high-position portion (1H), the thermal conductivity of the low-position portion (1L) is higher than the thermal conductivity of the high-position portion (1H). In addition, an electrical device of the embodiment has the electronic component mounting substrate (A) and an electronic component mounted on the first surface (1a). In addition, a light-emitting device of the embodiment has the electronic component mounting substrate (A) and a light-emitting element (4) mounted on the first surface (1a), and the electronic component mounting substrate (A) has a bank (5) on the first surface (1a) configured to surround the light-emitting element (4), and the bank (5) has an opening (5a) penetrating in the plane direction of the first surface (1a).

Description

Technical Field

[0001] The disclosed embodiments relate to an electronic component mounting substrate, an electric device, and a light emitting device. Background Art

[0002] Conventionally, electronic component mounting substrates made of ceramics or the like have been disclosed as housings for mounting electronic components such as semiconductor elements, light emitting elements, and crystal oscillators (for example, see Patent Document 1).

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2015-231009 Summary of the invention

[0006] A substrate for mounting electronic components according to one embodiment of the present invention comprises a plate-shaped base, a first surface of the base being inclined relative to a second surface opposite to the first surface, and when one side obtained by dividing the base in the inclined direction into two equal parts is used as a low-position portion and the other side is used as a high-position portion, the thermal conductivity of the low-position portion is higher than the thermal conductivity of the high-position portion.

[0007] An electric device according to the present embodiment includes the electronic component mounting substrate described above and an electronic component mounted on the first surface.

[0008] The light-emitting device of this embodiment comprises: the above-mentioned electronic component mounting substrate, and a light-emitting element mounted on the first surface, wherein the electronic component mounting substrate has a dam portion on the first surface configured to surround the light-emitting element, and the dam portion has an opening portion that passes through the first surface in the planar direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a perspective view showing an example of the electronic component mounting substrate according to the present embodiment.

[0010] Figure 2 yes Figure 1 Line ii cross-sectional view.

[0011] Figure 3 This is a perspective view of another embodiment of the electronic component mounting substrate.

[0012] Figure 4 yes Figure 3 Sectional view along line ii-ii.

[0013] Figure 5 This is a perspective view of another embodiment of the electronic component mounting substrate.

[0014] Figure 6 yes Figure 5 A plan view of a substrate for mounting electronic components is shown.

[0015] Figure 7 This is a perspective view of another embodiment of the electronic component mounting substrate.

[0016] Figure 8 It is an exploded perspective view showing an example of the light emitting device according to the present embodiment.

[0017] Fig. 9 It is a cross-sectional view showing one manufacturing process of the electronic component mounting substrate according to the present embodiment. DETAILED DESCRIPTION

[0018] Hereinafter, one embodiment of the electronic component mounting substrate, electric device, and light emitting device of the present embodiment will be described with reference to the drawings. Here, as the electronic component, semiconductor elements, light emitting elements, crystal oscillators, etc. can be cited.

[0019] Figure 1 It is a perspective view showing an example of the electronic component mounting substrate according to the present embodiment. Figure 2 yes Figure 1 Line ii cross-sectional view.

[0020] The electronic component mounting substrate A according to the present embodiment includes a plate-like base 1. In the present embodiment, an example is shown in which the base 1 includes a base body 6. An electronic component (not shown) is mounted on the center portion of the first surface 1a of the base 1.

[0021] like Figure 2 As shown, the first surface 1a of the base 1 is inclined relative to the second surface 1b of the opposite base 1. The inclination angle of the first surface 1a relative to the second surface 1b can be set to about 5° to 45°. In addition, the inclination of the first surface 1a relative to the second surface 1b may not be fixed, and may also include parts with different inclination angles. In the following, when the base 1 is divided into two by a surface orthogonal to the second surface 1b so that the length of the inclination direction of the first surface 1a is divided into two equal parts, the side with a lower average height is recorded as the low-position part 1L, and the side with a higher average height is recorded as the high-position part 1H.

[0022] Here, the average height refers to the average value of the height of the first surface 1a relative to the second surface 1b. When measuring the height, the height of 10 or more points may be measured along the inclination direction of the first surface 1a for each constant width.

[0023] In addition, when there are line segments of different lengths among the line segments connecting the ends of the first surface 1a and parallel to the inclination direction of the first surface 1a (for example, when the first surface 1a is a triangle, etc.), the length of the longest line segment among such line segments is referred to as the length in the inclination direction of the first surface 1a.

[0024] When the low portion 1L and the high portion 1H are defined as described above, from the viewpoint of thermal resistance, the heat generated from the electronic component mounted on the central portion of the first surface 1a is more likely to flow to the low portion 1L than to the high portion 1H. In other words, the heat flow through the low portion 1L is likely to be greater than the heat flow through the high portion 1H.

[0025] Therefore, when the thermal conductivity of the lower portion 1L or the higher portion 1H can be selectively increased, the thermal conductivity of the lower portion 1L must be increased. That is, the thermal conductivity of the lower portion 1L must be higher than the thermal conductivity of the higher portion 1H. Since the heat flow through the lower portion 1L is likely to be greater than the heat flow through the higher portion 1H, the heat dissipation of the electronic component mounting substrate A can be further improved by increasing the thermal conductivity of the lower portion 1L.

[0026] For example, after the base 1 is divided into the low-level portion 1L and the high-level portion 1H by cutting, the thermal conductivity of the low-level portion 1L and the high-level portion 1H can be measured by the laser flash method. In the case where the laser flash method is difficult to apply because the first surface 1a is inclined above a certain angle relative to the second surface 1b, the measurement can be performed as follows. First, after the base 1 is divided into the low-level portion 1L and the high-level portion 1H by cutting, thermal transient analysis is performed to measure the thermal resistance of the low-level portion 1L and the high-level portion 1H. The thermal transient analysis can be performed regardless of the inclination angle of the first surface 1a relative to the second surface 1b. Thereafter, the measured thermal resistance of the low-level portion 1L and the high-level portion 1H are divided by the average height of the low-level portion 1L and the high-level portion 1H, respectively, thereby obtaining the thermal resistance per unit height of the low-level portion 1L and the high-level portion 1H. The side with a smaller thermal resistance per unit height can be judged as having a higher thermal conductivity.

[0027] The base 1 can be mainly made of ceramic materials, but can also be mainly made of metal materials, organic materials, and glass materials. The base 1 can also contain a plurality of the above materials. Various ceramics can be applied to the base 1, but aluminum nitride (AlN) can be included as a main component from the viewpoint of having high thermal conductivity.

[0028] Here, "containing aluminum nitride as a main component" means that the base 1 contains 80 volume % or more of aluminum nitride, and further contains 90 volume % or more of aluminum nitride. If the base 1 contains aluminum nitride (AlN) as a main component, it is possible to form an electronic component mounting substrate A with better heat dissipation properties.

[0029] in addition, Figure 1 as well as Figure 2 Although not shown in the figure, in the electronic component mounting substrate A, conductors may be provided inside and on the surface of the base 1 as required.

[0030] Figure 3 It is a perspective view showing an example of the electronic component mounting substrate according to the embodiment. Figure 4 yes Figure 3 Sectional view along line ii-ii.

[0031] Figure 3 as well as Figure 4 The electronic component mounting substrate B shown in the figure shows one embodiment of the electronic component mounting substrate A described above, and the same reference numerals are given to common structures, and detailed description thereof will be omitted.

[0032] In the electronic component mounting substrate B, the base 1 has a base body 6, a via conductor 2, and a conductor pattern 3. The via conductor 2 is arranged inside the base 1, and the conductor pattern 3 is arranged on the first surface 1a and the second surface 1b of the base 1. The conductor pattern 3 may also be arranged on the side surface 1c of the base 1.

[0033] For example, in order to improve the heat dissipation of the electronic component mounting substrate B, when aluminum nitride (AlN) is mainly used in the base body 6, the thermal conductivity of the via conductor 2 may be lower than that of the base body 6. In this case, Figure 3 As shown in the figure, the number (volume) of the via-hole conductors 2 arranged in the low-positioned portion 1L is made smaller than the number (volume) of the via-hole conductors 2 arranged in the high-positioned portion 1H. As described above, since the heat flux through the low-positioned portion 1L is likely to be greater than the heat flux through the high-positioned portion 1H, the heat dissipation of the electronic component mounting substrate B can be further improved by reducing the number of via-hole conductors 2 arranged in the low-positioned portion 1L (reducing the volume).

[0034] Furthermore, the via-hole conductor 2 may not be disposed in the low-position portion 1L. That is, the via-hole conductor 2 may be disposed only in the high-position portion 1H. In this way, the heat dissipation property of the electronic component mounting substrate B can be further improved.

[0035] Here, aluminum nitride (AlN) is exemplified as a structural material of the base main body 6 , but various other materials can also be applied to the base main body 6 .

[0036] On the other hand, in the electronic component mounting substrate B, the thermal conductivity of the via-hole conductor 2 may be higher than the thermal conductivity of the base body 6. In this case, the number (volume) of the via-hole conductors 2 arranged in the low-position portion 1L may be greater than the number (volume) of the via-hole conductors 2 arranged in the high-position portion 1H. In this way, the heat dissipation of the electronic component mounting substrate B can be improved.

[0037] Furthermore, the via-hole conductors 2 may be disposed only in the low-position portion 1L. In this way, the heat dissipation property of the electronic component mounting substrate B can be further improved.

[0038] The thermal conductivity of the via-hole conductor 2 and the base body 6 can be measured using a laser flash method. If the laser flash method is difficult to apply due to the shape and size of the via-hole conductor 2 and the base body 6, the measurement can be performed as follows. For example, using the same structural material and manufacturing method as the via-hole conductor 2 and the base body 6, samples of shapes and sizes suitable for the laser flash method are prepared. If the thermal conductivity of such a sample is measured, the thermal conductivity of the via-hole conductor 2 and the base body 6 can be measured. Here, the so-called same structural material means that the composition is the same within a range of at least one decimal point.

[0039] However, in the above-mentioned electronic component mounting substrate B, the base 1 contains a first material and a second material having a lower thermal conductivity than the first material. Here, when the thermal conductivity of the via-hole conductor 2 is lower than the thermal conductivity of the base body 6, the base body 6 may be made of the first material and the via-hole conductor 2 may be made of the second material. On the other hand, when the thermal conductivity of the via-hole conductor 2 is higher than the thermal conductivity of the base body 6, the via-hole conductor 2 may be made of the first material and the base body 6 may be made of the second material.

[0040] When the base 1 does not have the via-hole conductor 2 , the component (main component) with the largest content among the components constituting the base body 6 and other components may be respectively made the first material or the second material according to the thermal conductivity.

[0041] At this time, the content rate (volume %) of the second material in the low portion 1L can be set lower than the content rate of the second material in the high portion 1H. In other words, the content rate (volume %) of the first material in the low portion 1L can be set higher than the content rate of the first material in the high portion 1H. As described above, the heat flux through the low portion 1L is likely to be greater than the heat flux through the high portion 1H. Therefore, by setting the content rate of the second material in the low portion 1L lower than the content rate of the second material in the high portion 1H, the heat dissipation of the electronic component mounting substrate B can be further improved.

[0042] The base body 6 can be mainly made of ceramic materials, but can also be mainly made of metal materials, organic materials, and glass materials. In addition, the base body 6 can also contain a plurality of the above materials. Various ceramics can be used for the base body 6, but from the perspective of having high thermal conductivity, aluminum nitride (AlN) can be included as a main component.

[0043] Various metal materials, alloys and composite materials are used for the via conductors 2 and the conductor patterns 3. When the base 1 contains aluminum nitride (AlN), a composite material of tungsten (W), molybdenum (Mo) and aluminum nitride (AlN) can be used from the viewpoint of co-firing.

[0044] A plating film of Ni or the like may be formed on the surface of the conductor pattern 3. Furthermore, a solder or Au-Sn plating film may be provided on the surface of such a plating film.

[0045] Figure 5 as well as Figure 7 It is a perspective view showing an example of the electronic component mounting substrate according to the embodiment. Figure 6 yes Figure 5 Top view of the . Figures 5 to 7 The electronic component mounting substrates C and D shown in FIG. 1 represent one embodiment of the electronic component mounting substrate B described above, and the same reference numerals are given to common structures, and detailed description thereof will be omitted.

[0046] exist Figure 5 In the electronic component mounting substrate C shown, the via-hole conductors 2 are arranged only at the peripheral edge of the base 1 in a plan view. This can increase the distance from the electronic component, which is a heat source, to the via-hole conductors 2. When the thermal conductivity of the via-hole conductors 2 is lower than the thermal conductivity of the base body 6, the heat dissipation of the electronic component mounting substrate C can be improved by arranging the via-hole conductors 2 as described above.

[0047] In addition, Figure 7 In the electronic component mounting substrate D shown in the figure, the via-hole conductors 2 are arranged only at the corners of the base 1 in a plan view. This can further increase the distance from the electronic component, which is a heat source, to the via-hole conductors 2. When the thermal conductivity of the via-hole conductors 2 is lower than the thermal conductivity of the base body 6, the heat dissipation of the electronic component mounting substrate D can be further improved by arranging the via-hole conductors 2 as described above.

[0048] On the other hand, when the thermal conductivity of the via-hole conductor 2 is higher than that of the base body 6, the via-hole conductor 2 may be arranged only in the central portion of the base 1 (not shown) in a plan view. This can shorten the distance from the electronic component, which is a heat source, to the via-hole conductor 2, thereby improving the heat dissipation of the electronic component mounting substrate C.

[0049] Here, the "peripheral portion of the base" and the "central portion of the base" are explained below. The first surface 1a of the base 1 is divided into three areas according to the distance from the area center of gravity of the first surface 1a. At this time, the first surface 1a can be divided so that the distance from the area center of gravity of the first surface 1a to the end of the first surface 1a is divided into three equal parts. The outermost area of ​​the divided first surface 1a is referred to as the peripheral area, and the innermost area is referred to as the central area. The situation in which the via-hole conductor 2 is only arranged directly below such a peripheral area when the base 1 is viewed from above is referred to as "the via-hole conductor is only arranged in the peripheral portion of the base when viewed from above". In addition, the situation in which the via-hole conductor 2 is only arranged directly below such a central area when the base 1 is viewed from above is referred to as "the via-hole conductor is only arranged in the central portion of the base when viewed from above".

[0050] Next, the "corner of the base" is explained below. On the first surface 1a of the base 1, the area within a certain distance from each vertex of the first surface 1a is referred to as a corner area. Here, the so-called certain distance can be set to 1 / 3 of the length of the line segment connecting each vertex of the first surface 1a and the area centroid of the first surface 1a. The situation where the via conductor 2 is only arranged directly below such a corner area when the base 1 is viewed from above is called "the via conductor is only arranged at the corner of the base when viewed from above".

[0051] like Figure 5 As shown, in the electronic component mounting substrate C, the via conductor 2 is connected to the conductor pattern 3 only at the peripheral portion of the conductor pattern 3 when viewed from above. In this case, the distance from the electronic component as a heat source to the via conductor 2 can also be increased. When the thermal conductivity of the via conductor 2 is lower than the thermal conductivity of the base body 6, the heat dissipation of the electronic component mounting substrate C can be improved by arranging the via conductor 2 as described above.

[0052] In addition, if Figure 7 As shown, in the electronic component mounting substrate D, the via conductor 2 is connected to the conductor pattern 3 only at the corner of the conductor pattern 3 when viewed from above. As a result, the distance from the electronic component as a heat source to the via conductor 2 can be further increased. In the case where the thermal conductivity of the via conductor 2 is lower than the thermal conductivity of the base body 6, the heat dissipation of the electronic component mounting substrate D can be further improved by arranging the via conductor 2 as described above.

[0053] On the other hand, when the thermal conductivity of the via-hole conductor 2 is higher than that of the base body 6, the via-hole conductor 2 may be connected to the conductor pattern 3 only in the center of the conductor pattern 3 (not shown) when viewed from above. This can shorten the distance from the electronic component, which is a heat source, to the via-hole conductor 2, thereby improving the heat dissipation of the electronic component mounting substrate C.

[0054] Here, the "peripheral portion of the conductor pattern" and the "central portion of the conductor pattern" are described below. Figure 6 As shown, a plane shape 33 of a similar shape to the first surface 1a of the base 1 is defined, which surrounds the entire conductor pattern 3. The area centroid of the plane shape 33 is configured to overlap with the area centroid of the first surface 1a. In addition, the plane shape 33 is set to the smallest area that can surround the entire conductor pattern 3. Here, the plane shape 33 is divided into three areas according to the distance from the area centroid of the plane shape 33. At this time, the plane shape 33 can be divided so that the distance from the area centroid of the plane shape 33 to the end of the plane shape 33 is divided into three equal parts. The outermost area of ​​the divided plane shape 33 is the peripheral area, and the innermost area is the central area. The situation in which the via conductor is connected to the conductor pattern 3 only directly below such a peripheral area when looking down on the base 1 is called "the via conductor is connected to the conductor pattern only at the peripheral portion of the conductor pattern when looking down". Furthermore, the case where the via-hole conductor 2 is connected to the conductor pattern 3 only directly below the central region when the base 1 is viewed in plan is referred to as “the via-hole conductor is connected to the conductor pattern only in the central portion of the conductor pattern when viewed in plan”.

[0055] Next, the "corner of the conductor pattern" is explained below. In the above-mentioned plane shape 33, the area within a certain distance from each vertex of the plane shape 33 is regarded as a corner area. Here, the so-called certain distance can be set to 1 / 3 of the length of the line segment connecting each vertex of the plane shape 33 and the area centroid of the plane shape 33. The situation where the via conductor 2 is connected to the conductor pattern 3 only directly below such a corner area when the base 1 is viewed from above is called "the via conductor is connected to the conductor pattern only at the corner of the conductor pattern when viewed from above".

[0056] Figure 8 1 is an exploded perspective view showing a light emitting device according to an embodiment. Figure 8 In the light emitting device E shown, any of the above-mentioned electronic component mounting substrates A to D can be used.

[0057] like Figure 8 As shown, in the light emitting device E, a light emitting element 4 is mounted on the central portion of the first surface 1a of the base 1. In addition, a laser diode or the like can be used as the light emitting element 4. Furthermore, a bank 5 is arranged on the first surface 1a so as to surround the mounted light emitting element 4. Figure 8 For convenience, the base 1 and the bank 5 are shown in an exploded form. The bank 5 has an opening 5a that passes through the first surface 1a in the plane direction. The opening 5a is provided to emit light from the light emitting element 4 to the outside of the light emitting device E. Figure 8In the embodiment, the light emitting surface 4a of the light emitting element 4 faces downward in the tilting direction of the first surface 1a, but the light emitting surface 4a may face upward in the tilting direction of the first surface 1a.

[0058] In the light emitting device E, the base 1 and the bank 5 can be integrally formed of ceramic. According to this structure, in the light emitting device E, an interface composed of different materials and generating a large thermal resistance is not generated between the base 1 and the bank 5. As a result, the thermal resistance between the base 1 and the bank 5 can be reduced, so that the heat dissipation of the light emitting device E can be improved.

[0059] The light emitting element 4 is bonded to the center of the first surface 1a using a conductive bonding material such as solder. In this case, the first electrode (not shown) provided on the lower surface of the light emitting element 4 may be electrically connected to the conductor pattern 3 via such a conductive bonding material.

[0060] The second electrode (not shown) provided on the upper surface of the light emitting element 4 and the conductive pattern 3 may be electrically connected by wire bonding or the like.

[0061] When an electronic component is mounted on the central portion of the first surface 1 a of the electronic component mounting substrates A to D to configure an electric device, such an electronic component is also electrically connected to the conductor pattern 3 as described above.

[0062] Next, a method for manufacturing the electronic component mounting substrate according to each embodiment will be described. Fig. 9 It is a cross-sectional view showing one manufacturing process of the electronic component mounting substrate A according to the embodiment.

[0063] First, if Fig. 9 As shown in the figure, a green sheet 11 processed into a rectangular shape is prepared in advance. Next, a stamping die 12 is used to perform stamping from the top to the bottom of the green sheet 11 to form a molded body 10 that becomes an electronic component mounting substrate A. The stamping die 12 is processed into a predetermined shape so that the first surface of the molded body 10 obtained after stamping is inclined relative to the second surface opposite to the first surface.

[0064] When manufacturing the electronic component mounting substrate A having the via conductor 2 and the conductor pattern 3 at least on the inside and the surface, the green sheet 11 having the via conductor 2 and the conductor pattern 3 formed in advance at least on the inside and the surface can be used.

[0065] Next, the produced compact 10 is fired (maximum temperature: 1500-1900° C.) to obtain the electronic component mounting substrate A.

[0066] When manufacturing the light emitting device E, the bank 5 can be obtained by molding it using molds of different shapes and firing it integrally with the molded body 10 .

[0067] As mentioned above, although embodiment of this disclosure was described, this disclosure is not limited to the said embodiment, Various changes are possible as long as they do not deviate from the summary.

[0068] Example

[0069] An electronic component mounting substrate is manufactured in which the first surface 1a of the base 1 is inclined relative to the second surface 1b facing the base 1, and a laser diode is mounted thereon as an electronic component, thereby manufacturing electrical devices of sample numbers 1 to 5 (hereinafter sometimes simply referred to as samples 1 to 5). In samples 1 to 5, the shape of the base 1 is all the same, but the arrangement of the via-hole conductor 2 in the base 1 is different. The manufacturing method of samples 1 to 5 is described below.

[0070] First, as a mixed powder for forming the green sheet 11 , a mixed powder was prepared in which 5% by mass of yttrium oxide powder and 1% by mass of calcium oxide powder were mixed with 94% by mass of aluminum nitride powder.

[0071] Next, 20 parts by mass of an acrylic binder and 50 parts by mass of toluene were added as an organic binder to 100 parts by mass of the mixed powder to prepare a slurry, and then a green sheet 11 having a predetermined thickness was produced by a doctor blade method.

[0072] Next, an acrylic organic binder and pinene alcohol are appropriately added to a mixed powder of tungsten powder and aluminum nitride powder at a ratio of 7:3 to prepare a conductor paste, which is used to form via conductors 2 and conductor patterns 3 on the green sheet 11 .

[0073] Then, using the above-mentioned green sheet 11, by Figure 8 The formed body 10 is produced by the production method shown in etc.

[0074] The produced compact 10 was fired in a reducing atmosphere at a maximum temperature of 1800° C. for 2 hours to produce an electronic component mounting substrate.

[0075] The shape of each electronic component mounting substrate after firing is 4 mm in length × 3 mm in width, and the first surface 1a of the base 1 is inclined in the length direction relative to the second surface 1b opposite thereto. The inclination angle of the first surface 1a relative to the second surface 1b is set to about 15°. The height is 1 mm at the lowest point and 2 mm at the highest point. For the above average height, the base 1 as a whole is 1.5 mm, the low part 1L is 1.25 mm, and the high part 1H is 1.75 mm.

[0076] The diameter of the via-hole conductor 2 after firing was 0.1 mm, and the porosity was 10%.

[0077] Next, a laser diode is mounted on the center portion of the first surface 1a of the manufactured electronic component mounting substrate. Here, Au-Sn solder is used to bond the electronic component to the first surface 1a.

[0078] In this way, samples 1 to 5 were produced.

[0079] Next, power was supplied to each of the fabricated samples 1 to 5 from outside the substrate, and thermal transient analysis was performed to measure thermal resistance. Here, the number of samples for each structure was set to n=5.

[0080] After that, the same substrate as the electronic component mounting substrate used in the preparation of samples 1 to 5 was divided into a lower portion 1L and a higher portion 1H by dicing. Then, laser diodes were mounted on each of them and power was supplied from an external source other than the substrate, and thermal transient analysis was performed again to measure the thermal resistance of the lower portion 1L and the higher portion 1H.

[0081] Next, in order to measure the thermal conductivity of the base body 6 and the via conductor 2 in each of the samples 1 to 5, a sample base body and a sample via conductor were produced with the same composition and firing conditions as above. The sample base body and the sample via conductor were set to a cylindrical shape with a diameter of 10 mm and a thickness of 1 mm. The thermal conductivity of the produced sample base body and the sample via conductor was measured using the laser flash method, and the results were 170 W / m·K and 100 W / m·K, respectively.

[0082] Table 1 shows the results of thermal resistance evaluation in each structure. Table 1 shows the value of thermal resistance per unit height obtained by dividing the measured thermal resistance by the average height of each. The smaller the thermal resistance per unit height, the higher the thermal conductivity. In addition, the average heights of the base 1, the low part 1L, and the high part 1H are set to 1.5 mm, 1.25 mm, and 1.75 mm, respectively.

[0083] In addition, the distance from the electronic component to the via-hole conductor in Table 1 is a distance connecting the center of the first surface 1 a of the base 1 and the center of the cross section of the via-hole conductor 2 along the first surface 1 a of the base 1 .

[0084] [Table 1]

[0085]

[0086] According to the measurement results of sample numbers 1, 4 and 5 in Table 1, when the thermal conductivity of the low-position part 1L or the high-position part 1H can be selectively improved, the thermal conductivity of the base 1 as a whole becomes higher when the thermal conductivity of the low-position part 1L is increased (the smaller the thermal resistance per unit height, the higher the thermal conductivity).

[0087] Similarly, the measurement results of Sample Nos. 1, 4, and 5 show that the thermal conductivity of the entire base 1 increases as the number of via-hole conductors 2 disposed in the low portion 1L decreases (the volume decreases) relative to the high portion 1H.

[0088] Furthermore, from the measurement results of Sample Nos. 1 to 3, it is found that the longer the distance between the via-hole conductor 2 and the electronic component as the heat source, the higher the thermal conductivity of the entire base 1 .

[0089] Explanation of symbols

[0090] A~D Substrates for mounting electronic components

[0091] E Lighting device

[0092] 1 abutment

[0093] 1a Surface 1 (of the abutment)

[0094] 1b Surface 2 (of the abutment)

[0095] 1c Side (of the abutment)

[0096] 1L Lower part (of the base)

[0097] 1H High part (of the base)

[0098] 2 Via conductor

[0099] 3 Conductor pattern

[0100] 4 Light-emitting components

[0101] 4a Light-emitting surface (of light-emitting element)

[0102] 5 Embankment

[0103] 5a Opening (of the bank)

[0104] 6 Abutment body

[0105] 10 formed body

[0106] 11 Green Film

[0107] 12 Stamping dies.

Claims

1. A substrate for mounting electronic components, comprising a plate-like base, The first surface of the base is inclined relative to a second surface opposite to the first surface. The first surface is a surface for mounting electronic components, and When the base is divided into two equal parts in the tilting direction, one side is used as the low-position part and the other side is used as the high-position part. The thermal conductivity of the low-position portion is higher than the thermal conductivity of the high-position portion. The base includes a first material and a second material having a lower thermal conductivity than the first material. The content rate of the second material in the low portion is lower than the content rate of the second material in the high portion.

2. The electronic component mounting substrate according to claim 1, wherein: The base has a base body and a via conductor. The thermal conductivity of the via conductor is higher than the thermal conductivity of the base body. The volume of the via-hole conductor arranged in the low-position portion is larger than the volume of the via-hole conductor arranged in the high-position portion.

3. A substrate for mounting electronic components, comprising a plate-like base, The first surface of the base is inclined relative to a second surface opposite to the first surface. The first surface is a surface for mounting electronic components, and When the base is divided into two equal parts in the tilting direction, one side is used as the low-position part and the other side is used as the high-position part. The thermal conductivity of the low-position portion is higher than the thermal conductivity of the high-position portion. The base has a base body and a via conductor. The thermal conductivity of the via conductor is lower than the thermal conductivity of the base body. The volume of the via-hole conductor arranged in the low-position portion is smaller than the volume of the via-hole conductor arranged in the high-position portion.

4. The electronic component mounting substrate according to claim 3, wherein: The number of the via-hole conductors arranged in the low-position portion is smaller than the number of the via-hole conductors arranged in the high-position portion.

5. The electronic component mounting substrate according to claim 3 or 4, wherein: The thermal conductivity of the via conductor is lower than the thermal conductivity of the base body, The via conductor is arranged only in the high-position portion.

6. The electronic component mounting substrate according to claim 3 or 4, wherein: The thermal conductivity of the via conductor is lower than the thermal conductivity of the base body, The via-hole conductor is arranged only on the peripheral edge portion of the base in a plan view.

7. The electronic component mounting substrate according to claim 3 or 4, wherein: The thermal conductivity of the via conductor is lower than the thermal conductivity of the base body, The via-hole conductors are arranged only at corners of the base in a plan view.

8. An electrical device comprising: The electronic component mounting substrate according to any one of claims 1 to 7; and The electronic component is mounted on the first surface.

9. A light emitting device, comprising: The electronic component mounting substrate according to any one of claims 1 to 7, and the light emitting element mounted on the first surface, The electronic component mounting substrate has a bank portion on the first surface arranged to surround the light emitting element. The bank portion has an opening portion penetrating in the planar direction of the first surface.

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