Electronic component mounting board

Abstract

To provide an electronic component mounting board that suppresses tilt of an electronic component relative to a board.SOLUTION: An electronic component mounting board according to an embodiment is an electronic component mounting board having a shape that is spaced apart in the width direction and extends in the depth direction D, and is provided with a plurality of component mounting pads 24 that are electrically connected to electrodes 34 of an electronic component 30 via solder 40, and at least one of the plurality of component mounting pads 24 has connection portions 24C, 24D that contact the solder 40 spaced apart in the depth direction D.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to a substrate for mounting electronic components. [Background technology]

[0002] Patent Document 1 discloses a structure in which a pair of soldering pads are each exposed through an opening in a solder resist. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-374060 A Summary of the Invention [Problem to be solved by the invention]

[0004] In an electronic component mounting board, it is desirable to suppress tilt of the electronic components with respect to the board. [Means for solving the problem]

[0005] The electronic component mounting board of the present disclosure is a board for mounting electronic components, comprising a plurality of component mounting pads spaced apart in a first direction, having a shape extending in a second direction, and electrically connected to electrodes of electronic components via solder, and at least one of the plurality of component mounting pads has a connection portion in contact with the solder spaced apart in the second direction.

[0006] According to the electronic component mounting board of the present disclosure, tilt of the electronic component with respect to the board is suppressed. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a top perspective view showing a part of the electronic component mounting board according to the embodiment; [Diagram 2] FIG. 2 is a top perspective view of the electronic component according to the embodiment, as viewed from the electrode side. [Diagram 3] FIG. 2 is a top view showing a state in which solder is printed on the electronic component mounting board of the embodiment. [Figure 4] Cross-sectional view taken along line 4-4 in FIG. 3 . [Diagram 5] 1 is a top view showing a state in which an electronic component is mounted on an electronic component mounting substrate on which solder is printed according to an embodiment, with a part of the electronic component 30 cut away. FIG. [Figure 6] 6 is a cross-sectional view taken along line 6-6 in FIG. 5, illustrating a state in which electronic components are mounted on the electronic component mounting substrate before reflow heating according to the embodiment. [Figure 7] 7 is a cross-sectional view corresponding to FIG. 6, illustrating a state of the electronic component mounting substrate after reflow heating according to the embodiment. [Figure 8] FIG. 13 is a top view showing a state in which an electronic component 30 is mounted on an electronic component mounting board on which solder is printed in a comparative embodiment, with a portion of the electronic component 30 cut away. [Figure 9] 9 is a cross-sectional view taken along line 9-9 in FIG. 8 , showing a state in which electronic components are mounted on an electronic component mounting board before reflow heating in a comparative example. [Figure 10] 10 is a cross-sectional view corresponding to FIG. 9, illustrating a state of an electronic component mounting substrate after reflow heating in a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an example of an embodiment of the present disclosure will be described in detail with reference to the drawings. Components indicated by the same reference numerals in each drawing are the same or similar components. Note that configurations and reference numerals that overlap in the embodiments described below may be omitted. In addition, all drawings used in the following description are schematic, and the dimensional relationships of each element, the ratios of each element, etc. shown in the drawings do not necessarily match the actual ones. In addition, the dimensional relationships of each element, the ratios of each element, etc. between multiple drawings do not necessarily match.

[0009] An electronic component 30 is mounted on the electronic component mounting board 20 of the embodiment.

[0010] 1 is a top perspective view showing a cut-out portion of an electronic component mounting board 20 according to an embodiment. In the following description, the portion of the electronic component mounting board 20 shown in each drawing will be simply referred to as the electronic component mounting board 20. The electronic component mounting board 20 is a rectangular plate including short sides extending in a depth direction (direction D in the drawing) as an example of a second direction and a certain direction, and long sides extending in a width direction (direction W in the drawing) as an example of a first direction and longer than the short sides. As shown in FIG. 4, the electronic component mounting board 20 includes an outermost insulating layer 22, a conductor layer 23, and a solder resist layer 26.

[0011] In the electronic component mounting board 20, a conductor layer 23 and a solder resist layer 26 are arranged in layers on an outermost insulating layer 22. The conductor layer 23 is mainly made of copper, is electrically conductive, and is arranged on the outermost insulating layer 22. The conductor layer 23 includes a pair of conductor pads 24 as an example of component mounting pads. The conductor layer 23 also includes a wiring pattern (not shown).

[0012] The solder resist layer 26 is a layer in which a solder resist is disposed on the outermost insulating layer 22. The solder resist layer 26 covers the conductor layer 23. The solder resist layer 26 has a plurality of openings 28 formed therein, which expose a portion of the conductor layer 23 without covering it. The openings 28 are an example of an opening. In FIG. 1, the portions of the solder resist layer 26 that do not cover the conductor layer 23 are the openings 28, and in this embodiment, four openings 28 are provided, which are rectangular and have the same shape and dimensions. The portions of the conductor layer 23 exposed through the openings 28 are the connection portions 24A, 24B, 24C, and 24D of the conductor pad 24.

[0013] The pair of conductor pads 24 are arranged extending in the depth direction and spaced apart in the width direction. Electrodes 34 of an electronic component 30 are mounted on the pair of conductor pads 24 (see FIG. 5). The pair of conductor pads 24 are rectangular in shape extending in the depth direction, have short sides along the width direction, and are plate-shaped with long sides extending in the depth direction perpendicular to the width direction and longer than the short sides. One conductor pad 24 includes connection parts 24A and 24B, and the other conductor pad 24 includes connection parts 24C and 24D. A portion of each of the pair of conductor pads 24 is covered with a solder resist layer 26, so that the connection parts 24A and 24B, which are in contact with the solder 40, and the connection parts 24C and 24D are exposed from the opening 28 with a distance G apart in the depth direction.

[0014] One conductor pad 24 is disposed on one end (end in the W direction in the figure) of the electronic component mounting board 20, and the connection portion 24A and the connection portion 24B are disposed in parallel to each other at a distance G in the depth direction of the electronic component mounting board 20. The other conductor pad 24 is disposed on the other end (end in the opposite direction to the W direction in the figure) of the electronic component mounting board 20, and the connection portion 24C and the connection portion 24D are disposed in parallel to each other at a distance G in the depth direction of the electronic component mounting board 20 (direction D in the figure). It is preferable to set the distance G in the range of 50 μm to 200 μm from the viewpoints of both solder connection reliability and suppression of component tilt. The multiple connection portions in the same conductor pad 24 are connected to each other by conductors and can be electrically connected when electricity is applied, but the connection portions in different conductor pads 24 are not connected to each other. The one conductor pad 24 and the other conductor pad 24 are separated by a distance S in the width direction. The distance S is longer than the distance G.

[0015] 2 is a top perspective view of an electronic component 30 according to an embodiment, as viewed from the electrode 34 side. The electronic component 30 is a two-terminal component, for example, a capacitor, particularly a silicon (Si) capacitor. The electronic component 30 is mounted on the electronic component mounting substrate 20 in the state shown in FIG. 1 in a state in which it is inverted from the state shown in FIG. The electronic component 30 is box-shaped and has a component body 32 and electrodes 34.

[0016] Component body 32 is in the shape of a flat box in the vertical direction, with short sides extending in the depth direction (direction D in the figure) and long sides extending in the width direction (opposite direction to direction W in the figure) that are longer than the short sides. Component body 32 houses circuit elements (not shown) of electronic component 30.

[0017] The electrodes 34 are a pair of conductors through which a current flows from a circuit element inside the component body 32. The electrodes 34 are rectangular in top view, have short sides along the width direction (longitudinal direction of the electronic component 30), and are plate-like with long sides extending along the depth direction perpendicular to the width direction and longer than the short sides. The electrodes 34 protrude from one surface (upper surface in the figure) of the component body 32. The long side of the first electrode 34 and the long side of the second electrode 34 are parallel to each other with a distance S between them. The pair of electrodes 34 are an example of electrodes at both ends in the longitudinal direction of the electronic component 30. The position of the electrodes 34 corresponds to the position of the conductor pad 24 on the electronic component mounting board 20. Specifically, the connection parts 24C and 24D of the second conductor pad 24 correspond to the first electrode 34 (the electrode on the opposite side of the W direction in the figure), and the connection parts 24A and 24B of the first conductor pad 24 correspond to the second electrode 34 (the electrode on the W direction side in the figure). That is, for a pair of conductor pads 24 corresponding to electrodes 34 at both ends in the longitudinal direction (width direction) of the electronic component 30, connection portions 24A and 24B in contact with the solder 40 in one conductor pad 24 are spaced apart in the depth direction. Also, connection portions 24C and 24D in contact with the solder 40 in the other conductor pad 24 are spaced apart in the depth direction. The electrodes 34 are longer in the depth direction than the corresponding pair of conductor pads 24 and have approximately the same length in the width direction, but are not limited to this.

[0018] 3 is a top view showing a state in which solder 40 is printed on the electronic component mounting board 20 of the embodiment. The solder 40 is printed on the connection portions 24A, 24B, 24C, and 24D. The method of printing the solder 40 on the electronic component mounting board 20 is performed by a well-known method.

[0019] Fig. 4 is a cross-sectional view taken along line 4-4 in Fig. 3. The center of the distance G between connection parts 24C and 24D in the depth direction is located in the center of electronic component mounting board 20 in the depth direction, and coincides with the center of electrode 34 in the depth direction (the center of the long side of electrode 34) (see Fig. 5). Solder 40 is printed on connection parts 24C and 24D, and solder 40 is piled up in layers in the height direction (direction H in the figure). The same can be said for connection parts 24A and 24B.

[0020] 5 is a top view showing a state in which an electronic component 30 is mounted on an electronic component mounting substrate 20 on which solder 40 of the embodiment is printed, with a portion of the electronic component 30 cut away. The electrodes 34 of the electronic component 30 are mounted above a pair of conductor pads 24 via the solder 40.

[0021] 5, showing a state in which an electronic component 30 is mounted on an electronic component mounting board 20 before reflow heating according to an embodiment. By melting the solder 40 on the connection parts 24C and 24D of the conductor pad 24 of the electronic component mounting board 20, the connection parts 24C and 24D of the conductor pad 24 and the electrodes 34 of the electronic component 30 are mechanically and electrically connected via the solder 40. A reflow furnace (not shown) is used to melt the solder 40.

[0022] Fig. 7 is a cross-sectional view corresponding to Fig. 6, showing a state of the electronic component mounting board 20 after reflow heating in the embodiment. The electronic component 30 is mounted on the electronic component mounting board 20 by reflow heating.

[0023] Next, a comparative example of the embodiment of the present disclosure will be described. The same configurations as those in the embodiment will be given the same names and descriptions thereof will be omitted.

[0024] Fig. 8 is a top view showing a state where an electronic component 30 is mounted on an electronic component mounting substrate 20 on which solder 40 is printed in a comparative embodiment, with a part of the electronic component 30 cut away. Fig. 9 is a cross-sectional view taken along line 9-9 in Fig. 8, showing a state where an electronic component 30 is mounted on an electronic component mounting substrate 20 before reflow heating in the comparative embodiment. Fig. 10 is a cross-sectional view corresponding to Fig. 9, showing a state of an electronic component mounting substrate 20 after reflow heating in the comparative embodiment. The dashed line portion in Fig. 10 indicates the position of an electronic component 30 with respect to an electronic component mounting substrate 20 before reflow heating in the comparative embodiment.

[0025] 8 and 9, the pair of conductor pads 24 in the comparative embodiment coincide with the connection portion that is in contact with the solder 40, and the conductor pads 24 are not separated (divided) in the depth direction. When the solder 40 is reflow-heated, the electronic component 30 may move on the electronic component mounting board 20 during heating due to convection in the reflow furnace, the printing position of the solder 40, the misalignment of the mounting position of the electronic component 30 relative to the electronic component mounting board 20, the shape of the solder 40, the melting difference of the solder 40, and the like. Therefore, when the electronic component mounting board 20 in the comparative embodiment is reflow-heated, the solder 40 melts on the conductor pads 24 as a unit, so that the solder 40 cannot resist the movement of the electronic component 30 in the depth direction, and the electronic component 30 may tilt to one side in the depth direction (FIG. 10).

[0026] On the other hand, in the electronic component mounting board 20 of the embodiment of the present disclosure, the connection portion 24C and the connection portion 24D of the conductor pad 24 are mechanically and electrically connected to the electrode 34 of the electronic component 30 via the solder 40 while being spaced apart by a distance G in the depth direction (FIG. 7). With the above configuration, even if the electronic component 30 moves in the up-down direction (the opposite direction to the H direction in the figure) during reflow heating, for example, the molten solder 40 does not move from the connection portion 24C to the connection portion 24D in the depth direction, and the solder 40 is distributed on each of the connection portions 24C and 24D to resist the movement of the electronic component 30. Therefore, compared to the comparative embodiment, the inclination of the electronic component 30 of the embodiment in the depth direction relative to the electronic component mounting board 20 is suppressed. From the viewpoint of the electronic component mounting board 20 of the embodiment of the present disclosure, when the electronic component 30 is mounted on the electronic component mounting board 20, the inclination of the electronic component 30 in the depth direction relative to the electronic component mounting board 20 is suppressed.

[0027] Moreover, the electronic component mounting board 20 according to the embodiment of the present disclosure further includes a solder resist layer 26 that covers a portion of the conductor pad 24, and a plurality of openings 28 that expose the connection portions 24A, 24B, 24C, and 24D are formed in the solder resist layer 26 (FIGS. 6 and 7). According to the above configuration, the electrical connection (area) between the electronic component mounting board 20 and the electronic component 30 is ensured with a simple configuration compared to a configuration in which the conductor pad 24 itself is divided.

[0028] 5, in the electronic component mounting board 20 according to the embodiment of the present disclosure, the width direction is perpendicular to the depth direction. According to the above configuration, even if the electronic component 30 is a long object, the inclination of the electronic component 30 can be suppressed. Furthermore, when the width direction corresponds to the longitudinal direction of the electronic component 30, the multiple conductor pads 24 at both ends of the longitudinal direction of the electronic component 30 are divided in the depth direction, so that the twisting of the entire electronic component 30 can be suppressed.

[0029] In the electronic component mounting board 20 according to the embodiment of the present disclosure, at least one of the conductor pads 24 has connection portions 24C and 24D that contact the solder 40 spaced apart at the center in the width direction ( FIG. 7 ). With the above configuration, compared to a configuration in which at least one of the conductor pads 24 has connection portions 24C and 24D that are separated at a position offset from the center in the width direction, the molten solder 40 can be divided evenly, so that the inclination of the electronic component 30 can be further suppressed and the electronic component 30 can be arranged on the electronic component mounting board 20 in a state closer to flat.

[0030] Although the present disclosure has been described in detail with respect to specific embodiments, it is clear to those skilled in the art that the present disclosure is not limited to such embodiments, and that the present disclosure can take various other embodiments within the scope of the present disclosure. For example, there are the following other examples, but the present disclosure is not limited to these.

[0031] [Example 1 of the embodiment] The first modified embodiment differs from the conductor pad 24 in the above embodiment in the following respects. First, the number of conductor pads 24 may be two or more in the width direction, and does not matter. In the case of three or more, it is preferable that the conductor pads 24 corresponding to the electrodes 34 at both ends in the width direction (longitudinal direction) are divided. Secondly, the conductor pad 24 is not limited to being divided by covering a part of the conductor layer 23 with the solder resist layer 26, and the conductor layer 23 may be physically divided into a plurality of parts. In addition, the conductor pads 24 are not limited to a pair, and only one conductor pad 24 may be provided with a plurality of connection parts. Although the plurality of connection parts in the same conductor pad 24 are connected by conductors, some or all of the connection parts may not be connected by conductors even if they are the same conductor pad 24. The shape of the connection part is the same as that of the opening 28 because the conductor pad is exposed from the opening 28, but it may be a different shape. For example, it may be a rectangular connection part inscribed inside the circular opening 28.

[0032] [Another embodiment 2] The second modified embodiment differs from the electrodes 34 in the above embodiment in the following respects. The electrodes 34 are arranged parallel to the electronic component 30 (FIGS. 2 and 5), but are not limited to this. The electrodes 34 may be arranged diagonally to the electronic component 30. The electrodes 34 are also arranged on both ends of the electronic component 30 in the longitudinal direction, but are not limited to this. For example, there may be three or more electrodes. In this case, the electronic component mounting board 20 is provided with conductor pads 24 in the number corresponding to the electrodes 34.

[0033] [Example 3 of the embodiment] The third modification of the embodiment differs from the openings 28 in the above embodiment in the following respects. In FIG. 1, four openings 28 are provided, but this is not limited to this. As in FIG. 1, the same number of openings 28 may correspond to each conductor pad 24, or the number of openings 28 may differ for each conductor pad 24. In addition, the openings 28 have the same shape and the same dimensions, but this is not limited to this. For example, some or all of the openings 28 may have different shapes or dimensions. The shape may be an arc, a combination of an arc and a rectangle, a cylinder, a square tube, etc.

[0034] [Example 4 of the embodiment] The fourth modified embodiment differs from the solder resist layer 26 that covers a part of the conductor layer 23 in the above embodiment in the following respects. The solder resist layer 26 covers a part of the conductor layer 23 in a linear shape (FIG. 3), but is not limited to this. The solder resist layer 26 may cover a part of the conductor layer 23 in a curved or wavy shape under the condition that the connection parts of the conductor pads 24 are spaced apart in the direction in which the electrodes 34 extend (depth direction). In addition, the solder resist layer 26 covers a part of the conductor layer 23 so as to be orthogonal (FIG. 1), but is not limited to this. For example, the solder resist layer 26 may cover a part of the conductor layer 23 so as to be crossed. [Explanation of symbols]

[0035] 20: Substrate for mounting electronic components 22: Outermost insulating layer 23: Conductive layer 24: Contact pad (component mounting pad) 24A: Connection 24B: Connection 24C: Connection 24D: Connection 26: Solder resist layer 28: Aperture (opening) 30: Electronic components 32: Part body 34: Electrode 40: Solder G: Depth distance between contact pads S: Widthwise separation between contact pads

Claims

1. An electronic component mounting substrate having a plurality of component mounting pads spaced apart in a first direction and extending in a second direction, the component mounting pads being electrically connected to electrodes of the electronic components via solder, At least one of the plurality of component mounting pads has a connection portion that contacts the solder and is spaced apart in the second direction.

2. The electronic component mounting substrate according to claim 1, The substrate further includes a solder resist layer that covers a portion of the component mounting pad, and the solder resist layer has a plurality of openings that expose the connection portions.

3. 2. The electronic component mounting board according to claim 1, wherein the first direction is perpendicular to the second direction.

4. 2. The electronic component mounting board according to claim 1, wherein the first direction corresponds to a longitudinal direction of the electronic component.

5. 5. The electronic component mounting board according to claim 4, wherein the connection portions of the component mounting pads respectively corresponding to the electrodes at both ends in the longitudinal direction of the electronic component are spaced apart from each other in the second direction.

6. 6. The electronic component mounting board according to claim 1, wherein the connection portion of at least one of the plurality of component mounting pads is spaced apart at the center in the second direction.

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