Circuit board and method for manufacturing mounting board

Abstract

This circuit board is provided with: a base material; the at least one pair of terminals are arranged on the base material; a bonding material that is disposed on the terminal and contains a metal element; and a wall made of an insulating material that rises from the base material in a height direction orthogonal to the main surface of the base material. The pair of terminals and the bonding material are disposed in the wall, and at least one groove portion penetrating from the inner peripheral surface to the outer peripheral surface is formed in at least one wall frame portion of the wall.

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a circuit substrate and a mounting substrate. Background Art

[0002] In recent years, with the development of electronics, the development of technology for mounting electronic components on substrates has been continuously developing. For example, a technology has been developed that mounts bare chips of semiconductor light-emitting elements represented by multiple light-emitting diodes (hereinafter referred to as "LEDs") used for lighting or display devices on a wiring substrate. For example, in Patent Document 1, an invention is disclosed that inserts and joins a semiconductor light-emitting element into a cavity that can easily position and arrange multiple semiconductor light-emitting elements. In addition, in Patent Document 2, a technology has also been developed that suppresses the pullout and solder bridge of semiconductor light-emitting elements in the installation of electronic components using a paste-like bonding material. [Prior art literature] [Patent Document]

[0003] Patent Document 1: Japanese Patent Application Publication No. 2006-93523 Patent Document 2: Japanese Patent Laid-Open No. 2004-47772 Summary of the invention [Problems to be solved by the invention]

[0004] Here, in the circuit substrate, terminals and bonding materials are sometimes arranged inside the wall of the insulating material. For such a circuit substrate, sometimes the constituent materials are filled inside the wall, electronic components are mounted using a retaining member, and the electronic components are pressed into the wall using a pressurized reflow soldering device to heat and bond them to the circuit substrate, thereby installing the electronic components. At this time, because the excess constituent materials are retained in the wall and the upper part of the wall around the electronic components, the electronic components cannot be fully pressed in during the pressurization process using the pressurized reflow soldering device, and there is a possibility of poor connection between the bonding materials of the circuit substrate and the electronic components.

[0005] An object of the present disclosure is to provide a method for manufacturing a circuit board and a mounting board that can suppress poor connection between a bonding material of the circuit board and an electronic component. [Technical means to solve the problem]

[0006] The circuit substrate disclosed in the present invention comprises: a substrate; at least one pair of terminals, which are arranged on the substrate; a bonding material, which is arranged on the terminals and contains a metal element; and a wall of insulating material, which stands up from the substrate in a height direction perpendicular to the main surface of the substrate; and a pair of terminals and the bonding material are arranged in the wall, and at least one wall frame portion in the wall forms at least one groove portion that passes through from the inner peripheral surface to the outer peripheral surface.

[0007] In the circuit substrate disclosed in the present invention, a pair of terminals and a bonding material are arranged in the wall. Here, at least one groove portion extending from the inner peripheral surface to the outer peripheral surface is formed in at least one wall frame portion in the wall. In this case, constituent materials are arranged in the wall, electronic components are mounted using a retaining member, and the electronic components are pressed into the interior of the wall using a pressurized reflow soldering device to heat and bond them to the circuit substrate, so that when the electronic components are installed on the circuit substrate, excess constituent materials can be discharged to the outside of the wall through the groove portion. Thus, in the pressurization process using the pressurized reflow soldering device, the electronic components can be fully pressed into the wall so that they are in contact with the bonding material. Based on the above, poor connection between the bonding material of the circuit substrate and the electronic components can be suppressed.

[0008] When viewed from the thickness direction of the wall frame portion, the groove portion extends toward the substrate side from the front end portion in the height direction of the wall frame portion, and the bottom surface of the groove portion is arranged at a position separated from the substrate. In this case, the range of the groove portion can be stopped at a part in the height direction. Therefore, excessive discharge of the constituent material can be suppressed. In addition, the strength of the wall frame portion can be ensured.

[0009] When the occupied area of ​​the wall frame portion when observing from the thickness direction of the wall frame portion is set to S, the opening area of ​​the groove portion is set to Sc, the width of the wall frame portion in the width direction orthogonal to the thickness direction and the height direction is set to W, and the length of the wall frame portion in the thickness direction is set to L, the following formula (1) and formula (2) are established. By satisfying formula (1), it is possible to suppress the difficulty of the constituent material to flow due to the ratio of the opening area being too small, and to suppress the outflow of the constituent material due to the excessively large and necessary amount. In addition, by satisfying formula (2), it is possible to suppress the difficulty of the constituent material to flow due to the narrowing pressure loss of the width W relative to the flow path length, that is, the length L, and to suppress the outflow of the constituent material due to the excessively wide width W. [Number 1]

[0010] When viewed from the thickness direction of the wall frame, the groove extends from the front end in the height direction of the wall frame toward the substrate side, and the width of the groove in the width direction orthogonal to the thickness direction and the height direction is greater on the front end side than on the bottom side. In this case, by narrowing the groove on the substrate side, the flow path resistance becomes larger, and the necessary constituent materials are retained, and by expanding the groove on the front end side, the excess constituent materials are easily discharged.

[0011] When viewed from the height direction, the width of the groove in the width direction orthogonal to the thickness direction and the height direction is larger on the inner side than on the outer side. The wider width of the groove on the inner side makes it easier for excess constituent material to enter the groove, but the narrower width of the groove on the outer side causes pressure loss, which can suppress excessive outflow of constituent material.

[0012] Observe from the height direction, at the corner where a pair of wall frame parts are connected to each other, form a recessed portion that is recessed on the outer peripheral side compared with the inner peripheral surface of the wall frame part. In this case, the wall frame part can not be disconnected from each other, and the unnecessary constituent material can flow in the corner.

[0013] The edge of the groove is rounded so that the constituent material can flow smoothly through the groove.

[0014] The dimension of the short side of the inner peripheral surface of the wall is 8 μm or more, and the dimension of the long side of the inner peripheral surface is 68 μm or less. In this case, the size of the inner peripheral side of the wall can be set to an appropriate size.

[0015] The manufacturing method of the mounting substrate disclosed in the present invention manufactures the mounting substrate by mounting electronic components on the above-mentioned circuit substrate, and after arranging constituent materials on a base material and arranging electronic components, a pressurized reflow device is used to join the electronic components to terminals.

[0016] In this case, the same functions and effects as those of the above-mentioned circuit board can be obtained. [Effects of the Invention]

[0017] According to the present disclosure, it is possible to provide a method for manufacturing a circuit board and a mounting board that can suppress poor connection between a bonding material of the circuit board and an electronic component. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic cross-sectional view showing a mounting substrate including a circuit substrate according to an embodiment of the present disclosure. Figure 2 It is a schematic cross-sectional view showing a circuit board according to an embodiment of the present disclosure. Figure 3 A top view of the circuit board. Figure 4 (a) is a diagram showing the wall frame portion 13C viewed from the thickness direction, i.e., the Y-axis direction. Figure 4 (b) is a diagram showing the wall frame portion 13C as viewed from the Z-axis direction. Figure 5 A diagram showing a groove portion of a circuit board according to a modified example. Figure 6 A diagram showing a groove portion of a circuit board according to a modified example. Figure 7 A diagram showing a groove portion of a circuit board according to a modified example. Figure 8 A diagram showing a circuit board according to a modified example. Fig. 9 A schematic cross-sectional view showing a method for manufacturing a circuit board and a mounting board. Fig.10 A schematic cross-sectional view showing a method for manufacturing a circuit board and a mounting board. Fig.11 This is a schematic cross-sectional view showing a method for manufacturing the wall portion. Fig.12 It is a schematic cross-sectional view showing a circuit board of a comparative example. Fig.13 This is a table showing the conditions and test results of Examples. Fig.14 This is a table showing the conditions and test results of Examples. DETAILED DESCRIPTION

[0019] Reference Figure 1 to Figure 3 , the circuit board 3 according to the embodiment of the present disclosure is described. Figure 1 It is a schematic cross-sectional view showing a mounting substrate 1 including a circuit substrate 3 according to an embodiment of the present disclosure. Figure 2 It is a schematic cross-sectional view showing the circuit board 3 according to the embodiment of the present disclosure. Figure 3 It is a top view of the circuit substrate 3.

[0020] like Figure 1 As shown, the mounting substrate 1 includes an electronic component 2 and a circuit substrate 3. The mounting substrate 1 is formed by mounting the electronic component 2 on the circuit substrate 3 via a bonding material 4.

[0021] The electronic component includes a main body 6 and a pair of terminals 7. The main body 6 is a member for performing the function as the electronic component 2. The terminal 7 is a metal portion formed on the main surface of the main body 6. As the material of the terminal 7, a metal such as Cu, Ti, Au, Ni, Sn, Bi, P, B, In, Ag, Zn, Pd, Mo, Pt, Cr, or an alloy of at least two selected from these metals is used. The electronic component 2 is composed of, for example, a micro LED. The micro LED is a component that emits light based on the input from the circuit board 3.

[0022] The circuit board 3 includes a substrate 8, a wall 9, and a pair of terminals 10. The substrate 8 is a flat plate-shaped main body of the circuit board 3. The substrate 8 has a main surface 8a. In the following description, there is a case where the description is made using XYZ coordinates set relative to the circuit board 3. The X-axis direction is a direction parallel to the main surface 8a of the substrate 8, the Y-axis direction is a direction parallel to the main surface 8a of the substrate 8 and perpendicular to the X-axis direction, and the Z-axis direction (height direction) is a direction perpendicular to the main surface 8a of the substrate 8.

[0023] The wall 9 is a member formed of an insulator formed on the main surface 8a of the substrate 8. The wall 9 stands from the substrate 8 toward the positive side in the Z-axis direction. Figure 3As shown, in the present embodiment, wall 9 has wall frame portions 13A, 13B, 13C, 13D arranged on all sides. Wall frame portions 13A, 13B are opposite to each other in the state spaced apart from each other in the X-axis direction, and expand in parallel in the Y-axis direction. Wall frame portion 13A is configured on the positive side of the X-axis direction, and wall frame portion 13B is configured on the negative side. Wall frame portions 13C, 13D are opposite to each other in the state spaced apart from each other in the Y-axis direction, and expand in parallel in the X-axis direction. Wall frame portion 13C is configured on the positive side of the Y-axis direction, and wall frame portion 13D is configured on the negative side. Wall frame portion 13A connects the ends of the positive side of the X-axis direction of wall frame portions 13C, 13D to each other. Wall frame portion 13B connects the ends of the negative side of the X-axis direction of wall frame portions 13C, 13D to each other. Thus, when observed from the Z-axis direction, wall 9 has a rectangular frame-shaped structure. Wall frame parts 13A and 13B constitute short sides, and wall frame parts 13C and 13D constitute long sides. In addition, although the size is not particularly limited, the size of the Y-axis direction of wall frame parts 13A and 13B can be set to 10 to 60 μm. The size of the X-axis direction of wall frame parts 13C and 13D can be set to 15 to 70 μm. The size of the short side of the inner peripheral surface of the interior of wall 9 can be set to more than 8 μm and less than 44 μm. The size of the long side of the inner peripheral surface of the interior of wall 9 can be set to more than 15 μm and less than 68 μm. The size of the short side of the inner peripheral surface of the interior of wall 9 is the size of the Y-axis direction of the inner peripheral surface 13a of wall frame part 13C and the inner peripheral surface 13a of wall frame part 13D. The size of the long side of the inner peripheral surface of the interior of wall 9 is the size of the X-axis direction of the inner peripheral surface 13a of wall frame part 13A and the inner peripheral surface 13a of wall frame part 13B. As the material of the wall 9, for example, a resin material such as epoxy resin, acrylic resin, phenolic resin, melamine resin, urea resin, alkyd resin, etc. is used. As the material of the wall 9, epoxy resin and acrylic resin are preferably used.

[0024] like Figure 1 to Figure 3 As shown, the terminal 10 is a metal portion formed on the main surface 8a of the substrate 8. As the material of the terminal 10, Ni, Cu, Ti, Cr, Al, Mo, Pt, Au, or an alloy of at least two selected from these, etc. are used. A conductive film 12 is formed on the terminal 10. As the material of the conductive film 12, a film of Ti, Cu, Ni, Al, Mo, Cr, Ag, etc., or a film of a mixture of metal particles and a binder, etc. are used.

[0025] The bonding material 4 is a member for bonding the terminal 7 of the electronic component 2 and the terminal 10 of the circuit board 3. The bonding material 4 is formed by thermally bonding the bonding material 4A on the circuit board 3 side and the bonding material 4B on the electronic component 2 side to form an integrated structure (see Fig.10(b)). The bonding material 4 may contain Sn, or may be composed of an alloy containing Sn. However, the bonding material 4 is not necessarily limited to that containing Sn. In addition to Sn, the bonding material 4 may also be composed of an alloy containing an element that lowers the melting point of Sn. As an element that lowers the melting point of Sn, for example, Bi can be cited. The bonding material 4 functions as a solder. Thus, between the substrate 8 and the main body 6, the terminal 10, the conductive film 12, the bonding material 4 and the terminal 7 are stacked in sequence from the upper surface of the substrate 8. In addition, in this part, welding is performed after the terminal 10, the conductive film 12, the bonding material 4 and the terminal 7 are stacked. Therefore, a structure in which the metals of the terminal 10, the conductive film 12, the bonding material 4 and the terminal 7 are melted and diffused is formed. This structure after welding may be a structure containing a brittle intermetallic compound (IMC: Intermetallic Compound). When a brittle structure, i.e., an intermetallic compound, is present, the reliability is easily reduced because it is easily broken by stress from the outside. Therefore, by surrounding the electronic component 2 with the wall 9 , there is an effect of protecting the electronic component 2 .

[0026] A recess 11 is formed in the wall 9. The recess 11 is formed by a through hole that penetrates the wall 9 in the Z-axis direction. Thus, the upper surface of the substrate 8 is exposed at the bottom side of the recess 11. The recess 11 is rectangular when viewed from the Z-axis direction (see Figure 3 Since the terminal 7, the terminal 10, the conductive film 12 and the bonding material 4 are arranged in the recess 11 formed in the wall 9, they are surrounded by the wall 9. A small gap is formed between the terminal 7, the terminal 10, the conductive film 12 and the bonding material 4 and the inner peripheral surface 13a of the four wall frame parts 13A, 13B, 13C, and 13D constituting the recess 11.

[0027] In the recess 11, a constituent material 20 is arranged between the electronic component 2 and the bonding material 4 and the wall 9. Thus, by supporting the constituent material 20, the electronic component 2 can be prevented from being easily peeled off from the circuit substrate 3. In addition, the force applied to the electronic component 2, the bonding material 4 or the terminals 7 and 10 can be alleviated, thereby improving reliability. As the material of the constituent material 20, for example, epoxy resin, acrylic resin, phenolic resin, melamine resin, urea-formaldehyde resin, alkyd resin or a mixture of these, or a mixture of the above resin materials with SiOx, ceramics, etc. is used. As the material of the constituent material 20, epoxy resin and acrylic resin are preferably used. The viscosity of the constituent material 20 during filling is preferably 1 to 20 Pa, and more preferably 5 to 10 Pa.

[0028] like Figure 2 As shown, the circuit substrate 3 has Figure 1The mounting substrate 1 shown in the figure is a structure after removing the electronic component 2 and the constituent material 20. In addition, in the circuit substrate 3, the bonding material 4A containing a metal element is arranged on the upper side of the terminal 10 (the upper side of the conductive film 12). As described above, the bonding material 4A constitutes a part of the bonding material 4 in the pre-stage of thermal bonding of the electronic component 2 and the mounting substrate 1. In the state of the circuit substrate 3, a pair of terminals 10, the conductive film 12 and the bonding material 4A are arranged in the wall 9 formed by the insulator.

[0029] like Figure 3 As shown, in wall frame portion 13A, 13B, 13C, 13D, form at least one groove portion 30 that penetrates to outer peripheral surface 13b from inner peripheral surface 13a. In addition, for wall frame portion 13A, 13B, X-axis direction is thickness direction. Therefore, the groove portion 30 of wall frame portion 13A, 13B extends in X-axis direction and penetrates wall frame portion 13A, 13B. In addition, for wall frame portion 13C, 13D, Y-axis direction is thickness direction. Therefore, the groove portion 30 of wall frame portion 13C, 13D extends in Y-axis direction and penetrates wall frame portion 13C, 13D. In addition, groove portion 30 only needs to be formed in at least one of wall frame portion 13A, 13B, 13C, 13D. In addition, multiple groove portions 30 can also be formed in wall frame portion 13A, 13B, 13C, 13D.

[0030] Secondly, refer to Figure 4 , the structure of the wall frame portion 13C when viewed from the thickness direction will be described. Figure 4 (a) is a diagram showing the wall frame portion 13C as viewed from the thickness direction, that is, the Y-axis direction. Figure 4 (b) is a diagram of the wall frame portion 13C viewed from the Z-axis direction. Figure 4 Although the wall frame portion 13C is shown in FIG. 1 , the same description also holds true for the other wall frame portions 13A, 13B, and 13D. Figure 4 As shown in (a), when viewed from the thickness direction of the wall frame portion 13C, i.e., the Y-axis direction, the groove portion 30 extends from the front end portion 13c of the wall frame portion 13C in the Z-axis direction toward the substrate 8 side (the negative side in the Z-axis direction). The groove portion 30 has a bottom surface 30a and a pair of side surfaces 30b. The bottom surface 30a is formed on the negative side of the Z-axis direction relative to the front end portion 13c. The pair of side surfaces 30b extend from both ends of the bottom surface 30a in the X-axis direction to the front end portion 13c. Figure 4 In the example shown in (a), the bottom surface 30a of the groove portion 30 is arranged at a position separated from the base material 8. Between the bottom surface 30a and the main surface 8a of the base material 8, a member of the wall frame portion 13C exists.

[0031] The occupied area of ​​the wall frame portion 13C when viewed from the thickness direction of the wall frame portion 13C, that is, the Y-axis direction, is denoted as S. The occupied area S is the area of ​​the wall frame portion 13C when the groove portion 30 is not formed, and corresponds to Figure 4The area of ​​the portion surrounded by the two-dot chain line in (a). The opening area of ​​the groove 30 is Sc. The opening area Sc is the area corresponding to the bottom surface 30a, the pair of side surfaces 30b and the imaginary front end 13c, corresponding to Figure 4 The area of ​​the part enclosed by the dotted line in (a). Figure 4 As shown in (b), the width of the wall frame portion 13C in the X-axis direction (width direction) is represented by W. The length of the wall frame portion 13C in the thickness direction, that is, the Y-axis direction is represented by L.

[0032] At this time, the following formula (1) and formula (2) are established. In addition, although the size range of width W is not particularly limited, it can be set in the range of 3 to 16 μm, for example. The length L is not particularly limited, but it can be set in the range of 5 to 20 μm, for example. In addition, formula (2) represents the sum of "W / L" when there are n grooves 30 in one wall frame portion 13. In addition, the opening area Sc is the sum of the opening areas of the n grooves 30. [Number 2]

[0033] like Figure 5 As shown, the groove portion 30 may also reach the main surface 8a of the substrate 8. In this case, the bottom surface 30a of the groove portion 30 is formed by the main surface 8a of the substrate 8. In this configuration, the region on the negative side of the wall frame portion 13C in the X-axis direction and the region on the positive side in the X-axis direction are separated by the groove portion 30.

[0034] like Figure 6 As shown in (a), the width of the groove 30 in the width direction, i.e., the X-axis direction, is greater on the front end 13c side than on the bottom surface 30a side. The width of the groove 30 in the front end 13c is greater than the width of the groove 30 in the bottom surface 30a. Figure 6 In the example shown in (a), the opening of the groove 30 in the X-axis direction becomes larger toward the front end portion 13c side. The pair of side surfaces 30b are inclined so that the distance between them increases toward the positive side in the Z-axis direction.

[0035] like Figure 6 As shown in (b), when viewed from the height direction, i.e., the Z-axis direction, the width of the groove 30 in the width direction, i.e., the X-axis direction, is greater on the inner side than on the outer side. The width of the groove 30 in the inner peripheral surface 13a is greater than the width of the groove 30 in the outer peripheral surface 13b. Figure 6 In the example shown in (b), the opening of the groove 30 in the X-axis direction becomes larger toward the inner peripheral surface 13a side. The pair of side surfaces 30b are inclined so that the distance between them increases toward the inner peripheral side, that is, the negative side in the Y-axis direction.

[0036] like Figure 7 As shown in FIG. 1 , the edge of the groove has a rounded arc (R angle). Figure 7As shown in (a), the edge 31 between the front end 13c and the side 30b has a rounded shape. The edge 32 between the bottom surface 30a and the side 30b has a rounded shape. Figure 7 As shown in (b), the edge portion 33 between the inner peripheral surface 13a and the side surface 30b is rounded, and the edge portion 34 between the outer peripheral surface 13b and the side surface 30b is rounded.

[0037] like Figure 8 As shown, when viewed from the height direction, i.e., the Z-axis direction, a recess 41 is formed at the corner 40 where a pair of wall frame portions are connected to each other, which is recessed toward the outer peripheral side relative to the inner peripheral surface 13a of the wall frame portion. For example, a rectangle T with a minimum area circumscribed to the inner peripheral surface 13a of the wall frame portion is set. At this time, in the four corners 40, the recess 41 can increase the area of ​​the rectangle T. The recess 41 is quadrilateral when viewed from the Z-axis direction, but can also be other polygons, and can also be circular.

[0038] Reference Fig. 9 and Fig.10 , the manufacturing method of the circuit substrate 3 and the mounting substrate 1 is described. First, Fig. 9 As shown in (a), a terminal 10 is formed on the upper surface of a substrate 8. Fig. 9 As shown in (b), the conductive film 12 and the bonding material 4 are formed on the upper surface of the terminal 10, and the wall 9 is formed on the base material 8. Thus, the circuit board 3 is completed. Fig. 9 As shown in (c), the constituent material 20 is filled in the concave portion 11, and the constituent material 20 is arranged on the base material 8. Then, the electronic component 2 is held by the holding member and the electronic component 2 is mounted in the concave portion 11. Fig.10 As shown, for the electronic component 2, the electronic component 2 is pressed into the concave portion 11 by the pressurized reflow soldering device 49, so that the bonding material 4A and the bonding material 4B are in contact with each other inside the constituent material 20. At this time, a part of the constituent material 20 is removed from the groove portion 30 (see Figure 3 ) flows out to the outside of the wall 9. Next, the bonding material 4B of the electronic component 2 is bonded to the bonding material 4A of the base material 8 by heating. Thus, the mounting substrate 1 is completed.

[0039] Secondly, refer to Fig.11 , a method for forming the wall 9 having the groove 30 is described. First, Fig.11 As shown in (a), a wall 9 is formed on a substrate 8. Next, as Fig.11 As shown in (b), a portion of the wall 9 is processed by irradiating the wall 9 with a laser device 51. Fig.11 As shown in (c), a groove 30 is formed in the wall 9.

[0040] Or, if Fig.11 As shown in (d), a resist 52 is formed on the substrate 8. Fig.11 As shown in (e), exposure is performed using a glass mask 53 having a pattern corresponding to the shape of the wall 9 having the groove 30. Fig.11 As shown in (f), the exposed resist 52 is developed to form the wall 9 having the groove portion 30.

[0041] Next, the operation and effects of the method for manufacturing the circuit board 3 and the mounting board 1 according to the present embodiment will be described.

[0042] First, refer to Fig.12 , the circuit board 103 of the comparative example is described. The wall 9 of the circuit board 103 does not have the above-mentioned groove portion 30. After the constituent material 20 is filled in the wall 9, the electronic component 2 is mounted in the wall 9 using a retaining member, and when the electronic component 2 is pressed in by a pressurized reflow soldering device, the electronic component 2 cannot be fully pressed in due to the influence of the excess constituent material 20. In this case, the reflow soldering is performed in a state where the bonding material 4B of the electronic component 2 is kept separated from the bonding material 4A of the circuit board 3, and there is a possibility that a poor connection between the bonding material 4A of the circuit board 3 and the electronic component 2 may occur.

[0043] In contrast, in the circuit substrate 3 of the present embodiment, a pair of terminals 10 and a bonding material 4A are arranged in the wall 9. Here, at least one groove 30 is formed in at least one wall frame portion 13 in the wall 9, which passes through from the inner peripheral surface 13a to the outer peripheral surface 13b. In this case, by arranging the constituent material 20 in the wall 9, using a retaining member to mount the electronic component, using a pressurized reflow soldering device 49 to press the electronic component 2 into the wall 9 and heat it to bond it to the circuit substrate 3, and when the electronic component 2 is mounted on the circuit substrate 3, the excess constituent material 20 can be discharged to the outside of the wall 9 through the groove 30. Thus, in the pressurization process using the pressurized reflow soldering device 49, the electronic component 2 can be fully pressed into the wall 9 so that it contacts the bonding material 4A. Based on the above, poor connection between the bonding material 4A of the circuit substrate 3 and the electronic component 2 can be suppressed.

[0044] Observe from the thickness direction of the wall frame portion 13, the groove portion 30 extends from the front end portion 13c on the height direction of the wall frame portion 13 to the base material 8 side, and the bottom surface 30a of the groove portion 30 is configured at a position separated from the base material 8. In this case, the scope of the groove portion 30 can be stopped at a part in the height direction. Therefore, excessive discharge of the constituent material 20 can be suppressed. In addition, the strength of the wall frame portion 13 can be ensured.

[0045] When the occupied area of ​​the wall frame portion 13 when observing from the thickness direction of the wall frame portion 13 is set to S, the opening area of ​​the groove portion 30 is set to Sc, the width of the wall frame portion 13 in the width direction orthogonal to the thickness direction and the height direction is set to W, and the length of the wall frame portion 13 in the thickness direction is set to L, the following formula (1) and formula (2) are established. By satisfying formula (1), it is possible to suppress that the constituent material 20 is difficult to flow because the ratio of the opening area is too small, and suppress the outflow of the constituent material 20 of the necessary amount due to excessive size. In addition, by satisfying formula (2), it is possible to suppress that the constituent material 20 is difficult to flow because the width W is narrowed relative to the flow path length, that is, the length L becomes large due to the pressure loss, and suppress the outflow of the constituent material 20 of the necessary amount due to the width W being too wide. [Number 3]

[0046] Observed from the thickness direction of the wall frame portion 13, the groove portion 30 extends from the front end portion 13c in the height direction of the wall frame portion 13 to the substrate 8 side, and the width of the groove portion 30 in the width direction orthogonal to the thickness direction and the height direction is that the front end portion 13c side can be larger than the bottom surface 30a side. In this case, by narrowing the groove portion 30 on the substrate 8 side, the flow path resistance becomes large and the necessary constituent material 20 is maintained, and by expanding the groove portion on the front end portion 13c side, it is easy to discharge the redundant constituent material 20.

[0047] When viewed from the height direction, the width of the groove 30 in the width direction orthogonal to the thickness direction and the height direction may be larger on the inner side than on the outer side. By widening the width of the groove 30 on the inner side, it is easy for the excess constituent material 20 to enter the groove 30, but by narrowing the width of the groove 30 on the outer side, pressure loss is generated, and excessive outflow of the constituent material 20 can be suppressed.

[0048] Observe from the height direction, at the corner 40 that a pair of wall frame portions 13 are connected to each other, can form the recessed portion 41 that is recessed to the outer peripheral side than the inner peripheral surface 13a of wall frame portion 13. In this case, can not make wall frame portion 13 be disconnected each other, and increase the flowable zone of unnecessary constituent material 20 at the corner 40.

[0049] The edges 31 , 32 , 33 , and 34 of the groove 30 are rounded. In this case, the constituent material 20 can flow through the groove 30 smoothly.

[0050] The short side of the inner peripheral surface of the wall 9 is 8 μm or more, and the long side of the inner peripheral surface is 68 μm or less. In this case, the size of the inner peripheral side of the wall 9 can be set to an appropriate size.

[0051] The manufacturing method of the mounting substrate 1 of the present embodiment is a method for manufacturing the mounting substrate 1 by mounting the electronic component 2 on the above-mentioned circuit substrate 3, and after the constituent material 20 is arranged on the substrate 8 and the electronic component 2 is arranged, the electronic component 2 is joined to the terminal 10 using a pressurized reflow soldering device 49.

[0052] In this case, the same functions and effects as those of the above-mentioned circuit board 3 can be obtained.

[0053] The present disclosure is not limited to the above-mentioned embodiments. For example, the number or arrangement of the terminals of the circuit substrate is not particularly limited. In addition, in the above-mentioned embodiments, one electronic component 2 is arranged in the wall 9, but a plurality of electronic components 2 may be arranged. The arrangement of the plurality of electronic components 2 is not particularly limited.

[0054] [Example] Embodiments of the mounting substrate of the present disclosure are described below. Note that the present disclosure is not limited to the following embodiments.

[0055] First, the mounting substrates of Examples 1 to 22 are prepared by the following manufacturing method. First, a wall 9 having a groove portion 30 is formed on a substrate 8 in a manner that surrounds the terminal 10 and the bonding material 4, thereby obtaining a circuit substrate 3. Next, the constituent material 20 is filled into the circuit substrate 3, and an LED chip as an electronic component 2 is mounted thereon. Next, the mounting substrate 1 in this state is pressurized at 0.01 MPa by a pressurized reflow device 49 and reflowed at 150°C to 190°C. Thus, the circuit substrate 3 and the electronic component 2 are bonded. The various conditions of Examples 1 to 20 are as follows. Fig.13 and Fig.14 In addition, Fig.13 and Fig.14 The "frame height (H)" in the table is the dimension in the height direction of the wall frame portion 13. The "frame width (L)" is the dimension in the thickness direction of the wall frame portion 13 (see Figure 4 (b)). "Groove width (W)" is the width W of the groove 30 (see Figure 4(b)). "Groove depth (Y)" is the dimension of the height direction of the groove. If "groove depth (Y)" is equal to "frame height (H)", it means that the groove 30 reaches the main surface 8a of the substrate 8. "Maximum diameter a in the X-axis direction" is the dimension of the long side of the inner peripheral surface of the wall 9. "Maximum diameter b in the Y-axis direction" is the dimension of the short side of the inner peripheral surface of the wall 9. "Number of grooves" is the number of grooves 30, "4" means that the grooves 30 are formed in the four wall frame parts 13, and "1" means that the grooves 30 are formed only in one of the wall frame parts 13 on the long side. "Chip size" is the size of the electronic component 2, that is, the LED chip. "Formula 1 value X" is the value of the above formula (1) in the X-axis direction. "Formula 1 value Y" is the value of the above formula (1) in the Y-axis direction. "Formula 2 value" is the value of the above formula (2). "Judgment" indicates the judgment result of the evaluation, and the double circle means that no carry-back defect occurs, and the difference between the chip height and the surface height of the cavity does not reach 0.2μm. Single turn means that the carry-back failure rate is less than 30%, and the difference between the chip height and the surface height of the chamber is greater than 0.2μm and less than 1.0μm. Triangle means that the carry-back failure rate is greater than 30%, or the difference between the chip height and the surface height of the chamber is greater than 1.0μm, or there is a problem such as the upper surface of the chip is not mounted parallel to the substrate. "Carry-back failure rate (%)" indicates the proportion of mounting substrates 1 with carry-back failure. Among 100 mounting substrates 1, Fig.10 When the pressurized reflow soldering device 49 is lifted in the state, the ratio of the number of electronic components 2 that are detached from the circuit substrate 3 and brought back by the pressurized reflow soldering device 49 is the return defect rate. "Δ(chip surface height-chamber surface height)" is the value of the gap between the upper surface of the electronic component 2, i.e., the LED chip, and the upper surface of the wall 9, and it is shown that the smaller the gap, the better the LED chip can be pressed in.

[0056] In addition, Fig.13 and Fig.14 In the embodiment 1 to 16, 21, and 22 satisfying both the formula (1) and the formula (2) and the embodiment 17 to 20 not satisfying at least one of the formula (1) and the formula (2) are compared. However, for the embodiment 17 to 20, by adjusting the constituent material 20, the effect is greater than that of the example in which the groove portion 30 is not formed in the wall frame portion 13.

[0057] First, in Example 17, since the groove width (W) is too large, the constituent material 20 flows out of the groove 30, so the LED chip cannot be retained, and more defective products are brought back. In Example 18, since the frame width (L) is small, the constituent material 20 flows out of the groove 30, so the LED chip cannot be retained, and more defective products are brought back. In Example 19, since the groove 30 is narrow and shallow, it is difficult for the constituent material 20 to flow from the groove 30, and it is difficult to press the LED chip in. In Example 20, since the frame width (L) of the wall frame 13 is large and the number of grooves 30 is small, it is difficult for the constituent material 20 to flow from the groove 30, and it is difficult to press the LED chip in.

[0058] In contrast, Examples 1 to 16, 21, and 22 satisfy both equations (1) and (2), thereby suppressing the carry-back failure and achieving good LED chip insertion. Example 1 can obtain the best result. In Example 2, since there is only one groove 30, the constituent material 20 is difficult to flow and tilts.

[0059] [Form 1] A circuit substrate comprising: Base material; At least one pair of terminals, which are disposed on the substrate; a bonding material disposed on the terminal and containing a metal element; and a wall of insulating material rising from the substrate in a height direction perpendicular to the main surface of the substrate; and A pair of the above-mentioned terminals and the above-mentioned bonding material are arranged in the above-mentioned wall; At least one wall frame portion in the wall is formed with at least one groove portion penetrating from the inner peripheral surface to the outer peripheral surface. [Form 2] A circuit substrate as in form 1, wherein the groove portion extends from a front end portion of the wall frame portion in the height direction toward the substrate side when viewed from the thickness direction of the wall frame portion, and the bottom surface of the groove portion is arranged at a position separated from the substrate. [Form 3] A circuit substrate as in form 1 or 2, wherein the occupied area of ​​the wall frame portion when viewed in the thickness direction of the wall frame portion is denoted as S, and the opening area of ​​the groove portion is denoted as Sc, When the width of the wall frame portion in a width direction perpendicular to the thickness direction and the height direction is represented by W and the length of the wall frame portion in the thickness direction is represented by L, the following equations (1) and (2) hold. [Number 4] [Form 4] A circuit substrate as in any one of aspects 1 to 3, wherein the groove portion extends from a front end portion of the wall frame portion in the height direction toward the substrate side when viewed in the thickness direction of the wall frame portion, The width of the groove portion in a width direction perpendicular to the thickness direction and the height direction is larger on the front end side than on the bottom surface side. [Form 5] A circuit substrate as in any one of forms 1 to 4, wherein the width of the groove portion in a width direction orthogonal to the thickness direction and the height direction is larger on the inner peripheral side than on the outer peripheral side when viewed from the height direction. [Form 6] A circuit substrate as in any one of forms 1 to 5, wherein, when viewed from the height direction, a recessed portion that is recessed toward the outer peripheral side relative to the inner peripheral surface of the wall frame portion is formed at a corner portion where a pair of the wall frame portions are connected to each other. [Form 7] A circuit substrate as in any one of forms 1 to 6, wherein the edge of the groove has a rounded arc. [Form 8] The circuit board according to any one of aspects 1 to 7, wherein the dimension of the short side of the inner peripheral surface inside the wall is 8 μm or more, and the dimension of the long side of the inner peripheral surface is 68 μm or less. [Form 9] A method for manufacturing a mounting substrate, the method comprising mounting an electronic component on a circuit substrate according to any one of aspects 1 to 8 to manufacture the mounting substrate; and After the constituent material is disposed on the substrate and the electronic component is disposed, the electronic component is bonded to the terminal using a pressure reflow device.

Explanation of symbols

[0060] 3: Circuit board 4A: Joining material 8: Base material 9: wall 10:Terminal 13A, 13B, 13C, 13D: Wall frame 20: Structural materials 30: Groove 31,32,33,34: Edge 40: Corner 41: concave part 49: Pressurized reflow soldering device.

Claims

1. A circuit substrate comprising: Base material; at least one pair of terminals, disposed on the substrate; A bonding material, disposed on the terminal and containing a metal element; and The wall of the insulating material rises from the substrate in a height direction perpendicular to the main surface of the substrate, A pair of the terminals and the bonding material are arranged in the wall. At least one wall frame portion in the wall is formed with at least one groove portion penetrating from the inner peripheral surface to the outer peripheral surface.

2. The circuit substrate according to claim 1, wherein: The groove portion extends from a front end portion of the wall frame portion in the height direction toward the base material when viewed in the thickness direction of the wall frame portion, and a bottom surface of the groove portion is arranged at a position spaced apart from the base material.

3. The circuit substrate according to claim 1, wherein: The occupied area of ​​the wall frame portion when viewed from the thickness direction of the wall frame portion is denoted as S, and the opening area of ​​the groove portion is denoted as Sc. When the width of the wall frame portion in the width direction orthogonal to the thickness direction and the height direction is set to W, and the length of the wall frame portion in the thickness direction is set to L, the following equations (1) and (2) are established: [Number 1] 4. The circuit substrate according to claim 1, wherein: When viewed in the thickness direction of the wall frame portion, the groove portion extends from a front end portion of the wall frame portion in the height direction toward the substrate side. The width of the groove portion in a width direction perpendicular to the thickness direction and the height direction is larger on the front end side than on the bottom surface side.

5. The circuit substrate according to claim 1, wherein: When viewed from the height direction, the width of the groove portion in the width direction perpendicular to the thickness direction and the height direction is greater on the inner peripheral side than on the outer peripheral side.

6. The circuit substrate according to claim 1, wherein: When viewed in the height direction, a recessed portion that is recessed toward the outer peripheral side from the inner peripheral surface of the wall frame portion is formed at a corner portion where the pair of wall frame portions are connected to each other.

7. The circuit substrate according to claim 1, wherein: The edge of the groove is rounded.

8. The circuit substrate according to claim 1, wherein: The short side dimension of the inner peripheral surface inside the wall is 8 μm or more, and the long side dimension of the inner peripheral surface is 68 μm or less.

9. A method for manufacturing a mounting substrate, wherein: A method for manufacturing a mounting substrate, wherein the mounting substrate is manufactured by mounting an electronic component on a circuit substrate according to any one of claims 1 to 8. After the constituent material is arranged on the substrate and the electronic component is arranged, the electronic component is bonded to the terminal using a pressure reflow device.

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