Joining material, temporary fixing method, and manufacturing method

Abstract

To realize temporary fixing with sufficient strength in a temporary fixing method in which a temporary fixing material is inserted into a through hole of a bonding material.SOLUTION: A bonding material 10 provided between an electronic circuit board 20 and an electronic component 30 when bonding the electronic component 30 to the electronic circuit board 20 includes a plate-shaped base material 7, at least one through hole 3 provided in the base material 7, into which a liquid temporary fixing material 40 is inserted, and a first groove portion 4 provided on the surface portion (first plate surface portion 1) of the bonding material 10 and communicating with the through hole 3, into which the temporary fixing material 40 permeates.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present disclosure relates to bonding materials and the like.

Background Art

[0002] When bonding an electronic component to an electronic circuit board (e.g., a printed circuit board), a bonding material such as solder is used. At this time, from the perspective of realizing temporary fixing of the electronic component to the electronic circuit board, a temporary fixing material such as flux is used. Patent Document 1 discloses a technique related to bonding using a temporary fixing material. Further, Patent Document 2 discloses another technique related to bonding using a temporary fixing material.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technique described in Patent Document 1, as shown in FIG. 3 of Patent Document 1, a bonding material (solder foil 11) is provided between an electronic circuit board (wiring board 1) and an electronic component (second electronic component 5). The bonding material (solder foil 11) has one through-hole (through-hole 15). When a temporary fixing material (solder flux layer 13) enters the one through-hole (through-hole 15), the temporary fixing material (solder flux layer 13) comes into contact with the electronic component (second electronic component 5). Thereby, temporary fixing of the electronic component (second electronic component 5) is realized (see, for example, paragraphs

[0026] and

[0050] of Patent Document 1).

[0005] However, as shown in Figure 3 of Patent Document 1, when using the single through-hole (through-hole 15), the contact area of ​​the temporary fixing material (solder flux layer 13) with respect to the electronic component (second electronic component 5) becomes smaller. As a result, the temporary fixing of the electronic component (second electronic component 5) becomes weaker. In particular, when a rotational force is applied to the electronic component (second electronic component 5) centered on the single through-hole (through-hole 15), the temporary fixing against the rotational force becomes weaker.

[0006] Thus, in the technology described in Patent Document 1, it was difficult to achieve sufficient strength in temporary fixing against the force applied to the electronic circuit board or electronic components before joining after temporary fixing. As a result, there was a problem that misalignment of the electronic components relative to the electronic circuit board could occur. Specifically, for example, there was a problem that misalignment in the rotational direction (so-called "rotational misalignment") could occur.

[0007] The purpose of this disclosure is, in light of the above-mentioned problems, to achieve sufficient strength in temporary fixing in a method in which a temporary fixing material is inserted into a through-hole of a jointing material. [Means for solving the problem]

[0008] A bonding material relating to one aspect of the present disclosure is a bonding material provided between an electronic circuit board and an electronic component when bonding an electronic component to an electronic circuit board, and comprises a plate-shaped base material, at least one through hole provided in the base material into which a liquid temporary fixing material enters, and a first groove provided on the surface of the base material and communicating with the through hole, into which the temporary fixing material penetrates.

[0009] One aspect of the present disclosure relates to a temporary fixing method for temporarily fixing an electronic circuit board and an electronic component when joining an electronic component to an electronic circuit board, and includes the steps of: placing a plate-shaped bonding material on the electronic circuit board at the position where the electronic component will be joined; filling a liquid temporary fixing material into a through-hole in the bonding material; and placing the electronic component on the bonding material, wherein the surface of the bonding material is provided with a first groove that communicates with the through-hole, and the temporary fixing material penetrates into the first groove.

[0010] A manufacturing method relating to one aspect of this disclosure is a method for manufacturing an electronic device comprising an electronic circuit board and an electronic component to be joined to the electronic circuit board, comprising the steps of: placing a plate-shaped bonding material on the electronic circuit board at the position where the electronic component is to be joined; introducing a liquid temporary fixing material into the through-hole of the bonding material; and placing the electronic component on the bonding material, wherein the surface of the bonding material is provided with a first groove that communicates with the through-hole, and the temporary fixing material penetrates into the first groove. [Effects of the Invention]

[0011] According to this disclosure, in a temporary fixing method in which a temporary fixing material is inserted into a through-hole of a jointing material, sufficient strength can be achieved in the temporary fixing. [Brief explanation of the drawing]

[0012] [Figure 1A] Figure 1A is a plan view of the joining material according to the first embodiment. [Figure 1B] Figure 1B is a bottom view of the joining material according to the first embodiment. [Figure 1C] Figure 1C is a cross-sectional view along the line A1-A1 shown in Figures 1A and 1B. [Figure 1D] Figure 1D is a cross-sectional view along the line B1-B1 shown in Figures 1A and 1B. [Figure 2A] Figure 2A is an explanatory diagram showing a method for joining electronic components to an electronic circuit board using a bonding material according to the first embodiment. [Figure 2B] Figure 2B is an explanatory diagram showing a method for joining electronic components to an electronic circuit board using a bonding material according to the first embodiment. [Figure 2C] Figure 2C is an explanatory diagram showing a method for joining electronic components to an electronic circuit board using a bonding material according to the first embodiment. [Figure 3A] Figure 3A is an explanatory diagram showing a method for joining electronic components to an electronic circuit board using a comparative bonding material. [Figure 3B] Figure 3B is an explanatory diagram showing a method for joining electronic components to an electronic circuit board using a comparative bonding material. [Figure 3C] Figure 3C is an explanatory diagram showing a method of joining an electronic component to an electronic circuit board using a comparative bonding material. [Figure 3D] Figure 3D is an explanatory diagram showing a method of joining an electronic component to an electronic circuit board using a comparative bonding material. [Figure 3E] Figure 3E is an explanatory diagram showing a method of joining an electronic component to an electronic circuit board using a comparative bonding material. [Figure 4A] Figure 4A is a plan view of the bonding material according to the second embodiment. [Figure 4B] Figure 4B is a bottom view of the bonding material according to the second embodiment. [Figure 4C] Figure 4C is a cross-sectional view taken along the line A2 - A2 shown in FIGS. 4A and 4B. [Figure 4D] Figure 4D is a cross-sectional view taken along the line B2 - B2 shown in FIGS. 4A and 4B. [Figure 5A] Figure 5A is a plan view of the bonding material according to the third embodiment. [Figure 5B] Figure 5B is a bottom view of the bonding material according to the third embodiment. [Figure 5C] Figure 5C is a cross-sectional view taken along the line A3 - A3 shown in FIGS. 5A and 5B. [Figure 5D] Figure 5D is a cross-sectional view taken along the line B3 - B3 shown in FIGS. 5A and 5B. [Figure 6A] Figure 6A is a plan view of the bonding material according to the fourth embodiment. [Figure 6B] Figure 6B is a bottom view of the bonding material according to the fourth embodiment. [Figure 6C] Figure 6C is a cross-sectional view taken along the line A4 - A4 shown in FIGS. 6A and 6B. [Figure 6D] Figure 6D is a cross-sectional view taken along the line B4 - B4 shown in FIGS. 6A and 6B. [Figure 7A] Figure 7A is a plan view of the bonding material according to the fifth embodiment. [Figure 7B] Figure 7B is a bottom view of the bonding material according to the fifth embodiment. [Figure 7C]Figure 7C is a cross-sectional view along the line A5-A5 shown in Figures 7A and 7B. [Figure 7D] Figure 7D is a cross-sectional view along the line B5-B5 shown in Figures 7A and 7B. [Figure 8A] Figure 8A is a plan view of the joint material according to the sixth embodiment. [Figure 8B] Figure 8B is a bottom view of the joint material according to the sixth embodiment. [Figure 8C] Figure 8C is a cross-sectional view along the line A6-A6 shown in Figures 8A and 8B. [Figure 8D] Figure 8D is a cross-sectional view along the line B6-B6 shown in Figures 8A and 8B. [Modes for carrying out the invention]

[0013] The embodiments of this disclosure will be described in detail below with reference to the attached drawings. [First Embodiment] Figure 1A is a plan view of the joint according to the first embodiment. Figure 1B is a bottom view of the joint according to the first embodiment. Figure 1C is a cross-sectional view along the line A1-A1 shown in Figures 1A and 1B. Figure 1D is a cross-sectional view along the line B1-B1 shown in Figures 1A and 1B. The joint according to the first embodiment will be described with reference to Figures 1A to 1D.

[0014] As shown in Figures 1A to 1D, the bonding material 10 comprises a plate-shaped or substantially plate-shaped base material 7. Specifically, for example, the bonding material 10 comprises a rectangular plate-shaped base material 7. The base material 7 is made of, for example, a solder sheet or solder foil. That is, the base material 7 is made of, for example, solder.

[0015] Hereinafter, plate-shaped or nearly plate-shaped materials will be collectively referred to simply as "plate-shaped." Furthermore, of the two plate-shaped substrates 7, one plate-shaped

[0016] At least one through-hole 3 is formed in the base material 7. Specifically, for example, two through-holes 3_1 and 3_2 are formed. The shape of each through-hole 3 is, for example, cylindrical or substantially cylindrical. That is, as shown in Figures 1A and 1B, the cross-sectional shape of each through-hole 3 is circular or substantially circular. Hereinafter, one of the two through-holes 3_1 and 3_2 may be referred to as the "first through-hole," and the other through-hole 3_2 may be referred to as the "second through-hole."

[0017] Furthermore, the shape of each through-hole 3 is not limited to a cylindrical or substantially cylindrical shape. For example, the shape of each through-hole 3 may be an elliptical or substantially elliptical shape. Alternatively, for example, the shape of each through-hole 3 may be a polygonal or substantially polygonal shape.

[0018] The first plate surface portion 1 of the base material 7 has at least one groove portion (hereinafter referred to as "first groove portion") 4 that communicates with each through hole 3. Specifically, for example, as shown in Figure 1A, four first groove portions 4_1_1 to 4_1_4 are formed that communicate with the through hole 3_1. In addition, four first groove portions 4_2_1 to 4_2_4 are formed that communicate with the through hole 3_2.

[0019] In the examples shown in Figures 1A to 1D, the first grooves 4_1_1 to 4_1_4 are arranged radially with respect to the through hole 3_1. That is, as shown in Figure 1A, the shape of each of the first grooves 4_1_1 to 4_1_4 is straight or substantially straight. In addition, one of the two ends of each of the first grooves 4_1_1 to 4_1_4 (hereinafter referred to as the "first end" or "one end") is in communication with the through hole 3_1.

[0020] In the examples shown in Figures 1A to 1D, the first grooves 4_2_1 to 4_2_4 are arranged radially with respect to the through hole 3_2. That is, as shown in Figure 1A, the shape of each of the first grooves 4_2_1 to 4_2_4 is straight or substantially straight. In addition, one of the two ends of each of the first grooves 4_2_1 to 4_2_4 (hereinafter referred to as the "first end" or "one end") is in communication with the through hole 3_2.

[0021] The second plate surface portion 2 of the base material 7 has at least one groove portion (hereinafter referred to as "second groove portion") 5 that communicates with each through hole 3. Specifically, for example, as shown in Figure 1B, four second groove portions 5_1_1 to 5_1_4 that communicate with the through hole 3_1 are formed. In addition, four second groove portions 5_2_1 to 5_2_4 that communicate with the through hole 3_2 are formed.

[0022] In the examples shown in Figures 1A to 1D, the second grooves 5_1_1 to 5_1_4 are arranged radially with respect to the through hole 3_1. That is, as shown in Figure 1B, the shape of each of the second grooves 5_1_1 to 5_1_4 is straight or substantially straight. In addition, one end of each of the second grooves 5_1_1 to 5_1_4 (hereinafter referred to as the "first end" or "one end") is in communication with the through hole 3_1.

[0023] In the examples shown in Figures 1A to 1D, the second grooves 5_2_1 to 5_2_4 are arranged radially with respect to the through hole 3_2. That is, as shown in Figure 1B, the shape of each of the second grooves 5_2_1 to 5_2_4 is straight or nearly straight. Also, one end of each of the second grooves 5_2_1 to 5_2_4 (hereinafter referred to as the "first end" or "one end") is in communication with the through hole 3_2.

[0024] In this way, the main part of the joining material 10 is constructed.

[0025] Next, with reference to Figures 2A to 2C, a method for joining electronic components 30 to an electronic circuit board 20 using bonding material 10 will be described.

[0026] First, as shown in Figure 2A, a liquid, paste, or cream-type temporary fixing material 40 is applied to the electronic circuit board 20. Hereinafter, liquid, paste, or cream-type materials will be collectively referred to simply as "liquid." The liquid temporary fixing material 40 has viscosity. For example, a dispenser D is used to apply the liquid temporary fixing material 40. The electronic circuit board 20 is made up of, for example, a printed circuit board.

[0027] At this time, the temporary fixing material 40 is applied to the positions on the electronic circuit board 20 where the electronic components 30 are joined. In other words, the temporary fixing material 40 is applied to the positions on the electronic circuit board 20 where the bonding material 10 is placed. More specifically, the temporary fixing material 40 is applied to the positions corresponding to the individual through holes 3 in the bonding material 10. In the example shown in Figure 2A, temporary fixing material 40_1 is applied to the position corresponding to through hole 3_1, and temporary fixing material 40_2 is applied to the position corresponding to through hole 3_2.

[0028] The temporary fixing material 40 is, for example, a resin that volatilizes upon heating during solder reflow. Hereinafter, such a volatilizing resin will be referred to as a "volatile resin." Alternatively, for example, the temporary fixing material 40 is a thermosetting resin that hardens upon heating during solder reflow. Specifically, for example, the temporary fixing material 40 is a flux.

[0029] Next, as shown in Figure 2B, the bonding material 10 is placed on the electronic circuit board 20. More specifically, the bonding material 10 is placed on the electronic circuit board 20 where the temporary fixing material 40 has been applied. That is, the bonding material 10 is placed on the electronic circuit board 20 where the electronic components 30 will be bonded. As a result, the second plate surface portion 2 of the bonding material 10 comes into contact with the electronic circuit board 20. Note that in Figures 2B and 2C, the reference numerals for each part of the bonding material 10 are omitted from the illustration.

[0030] In the diagram, arrow A_1 indicates the direction of movement of the bonding material 10 when it is placed on the electronic circuit board 20. In other words, arrow A_1 indicates the direction of the force applied to the bonding material 10 when it is placed on the electronic circuit board 20.

[0031] At this time, the temporary fixing material 40_1 penetrates into the individual second grooves 5_1 that communicate with the through holes 3_1. The penetrated temporary fixing material 40_1 comes into contact with the electronic circuit board 20 and also comes into contact with the bonding material 10. Similarly, the temporary fixing material 40_2 penetrates into the individual second grooves 5_2 that communicate with the through holes 3_2. The penetrated temporary fixing material 40_2 comes into contact with the electronic circuit board 20 and also comes into contact with the bonding material 10. This achieves temporary fixing of the electronic circuit board 20 and the bonding material 10.

[0032] Furthermore, due to the so-called "capillary action," the liquid temporary fixing material 40_1 enters the through hole 3_1 and rises inside the through hole 3_1. The rising temporary fixing material 40_1 then permeates into the individual first grooves 4_1 that communicate with the through hole 3_1 in the first plate surface 1. Similarly, the liquid temporary fixing material 40_2 enters the through hole 3_2 and rises inside the through hole 3_2. The rising temporary fixing material 40_2 then permeates into the individual first grooves 4_2 that communicate with the through hole 3_2 in the first plate surface 1.

[0033] Furthermore, from the viewpoint of generating capillary action in each through-hole 3, it is preferable that the inner diameter of each through-hole 3 be set to a value smaller than the diameter of the temporary fixing material 40 applied by the dispenser D (the so-called "coating diameter" or "coating size"). In addition, it is preferable that the bonding material 10 be held or guided so as not to shift position relative to the electronic circuit board 20 due to the intrusion and penetration of the temporary fixing material 40 by capillary action.

[0034] Next, as shown in Figure 2C, the electronic component 30 is placed on the bonding material 10. This brings the first plate surface portion 1 of the bonding material 10 into contact with the electronic component 30. The electronic component 30 is, for example, a surface mount component. Specifically, for example, the electronic component 30 is made up of a bare chip for face-up mounting. A chuck (not shown) is used to place the electronic component 30. That is, the chuck grips the side portion of the electronic component 30 and places the electronic component 30 on the bonding material 10.

[0035] At this time, the temporary fixing material 40_1 that has permeated each first groove 4_1 comes into contact with the bonding material 10 and also comes into contact with the electronic component 30. Similarly, the temporary fixing material 40_2 that has permeated each first groove 4_2 comes into contact with the bonding material 10 and also comes into contact with the electronic component 30. This achieves temporary fixing of the bonding material 10 and the electronic component 30.

[0036] In this way, the electronic circuit board 20 and the bonding material 10 are temporarily fixed together, and the bonding material 10 and the electronic component 30 are temporarily fixed together. As a result, the electronic circuit board 20 and the electronic component 30 are temporarily fixed together.

[0037] Next, the unit U, which includes the bonding material 10, the electronic circuit board 20, the electronic components 30, and the temporary fixing material 40, is placed in a reflow oven (not shown). Then, solder reflow is performed. Specifically, for example, a reduction reflow using formic acid or hydrogen is performed. As a result, the solder constituting the base material 7 of the bonding material 10 melts, and the bonding of the electronic circuit board 20 and the electronic components 30 is achieved.

[0038] In this case, if the temporary fixing material 40 is made of a volatile resin, the temporary fixing material 40 will volatilize due to heating in the reflow oven. This can create spaces corresponding to the hollow parts (including the individual through holes 3, individual first grooves 4, and individual second grooves 5) in the joining material 10 before heating. At this time, the molten solder will flow and fill these spaces. By filling these spaces with solder, the soldering area can be increased. As a result, a strong bond is achieved.

[0039] On the other hand, if the temporary fixing material 40 is made of thermosetting resin, the temporary fixing material 40 hardens when heated in a reflow oven. The hardened temporary fixing material 40 functions as an adhesive. In other words, the thermosetting temporary fixing material 40 functions as both a temporary fixing material and a bonding material. A strong bond is achieved because the bonding material 10 functions as a bonding material, and the temporary fixing material 40 also functions as a bonding material.

[0040] In this case, from the viewpoint of properly curing the temporary fixing material 40, the thermal profile in the reduction reflow process may be set to an appropriate profile. The temperature of the reflow oven may also be controlled based on the set thermal profile.

[0041] The bonding process shown in Figures 2A to 2C (including the temporary fixing process) is typically included in the process of manufacturing electronic equipment (not shown) comprising an electronic circuit board 20 and electronic components 30.

[0042] Next, with reference to Figures 3A to 3E, a comparative bonding material 10' will be described. Furthermore, a method for bonding electronic components 30' to an electronic circuit board 20' using bonding material 10' will be explained.

[0043] The shape of the joining material 10' is plate-like. That is, the shape of the joining material 10' is the same as the shape of the joining material 10. However, the joining material 10' does not have through holes corresponding to the individual through holes 3 in the joining material 10. Also, the joining material 10' does not have grooves corresponding to the individual first grooves 4 in the joining material 10. Also, the joining material 10' does not have grooves corresponding to the individual second grooves 5 in the joining material 10.

[0044] First, as shown in Figure 3A, a liquid temporary fixing material 40' is applied to the electronic circuit board 20'. The liquid temporary fixing material 40' is viscous. For example, a dispenser D' is used to apply the liquid temporary fixing material 40'.

[0045] The electronic circuit board 20' is the same as the electronic circuit board 20. The temporary fixing material 40' is the same as temporary fixing material 40'. In the example shown in Figure 3B, temporary fixing material 40'_1 is applied in the same position as temporary fixing material 40_1, and temporary fixing material 40'_2 is applied in the same position as temporary fixing material 40_2. The dispenser D' is the same as dispenser D.

[0046] Next, as shown in Figure 3B, the bonding material 10' is placed on the electronic circuit board 20'. More specifically, the bonding material 10' is placed on the electronic circuit board 20' where the temporary fixing material 40' has been applied. That is, the bonding material 10' is placed on the electronic circuit board 20' where the electronic components 30' will be bonded.

[0047] In the diagram, arrow A'_1 indicates the direction of movement of the bonding material 10' when it is placed on the electronic circuit board 20'. In other words, arrow A'_1 indicates the direction of the force applied to the bonding material 10' when it is placed on the electronic circuit board 20'.

[0048] At this time, the temporary fixing material 40' applied to the electronic circuit board 20' spreads between the electronic circuit board 20' and the bonding material 10'. This spread temporary fixing material 40' provides temporary fixation between the electronic circuit board 20' and the bonding material 10'.

[0049] Next, as shown in Figure 3C, a liquid temporary fixing material 50' is applied to the bonding material 10'. The liquid temporary fixing material 50' is viscous. For example, a dispenser D' is used to apply the liquid temporary fixing material 50'. The temporary fixing material 50' is the same as the temporary fixing material 40'. In the example shown in Figure 3C, temporary fixing material 50'_1 is applied in the same position as temporary fixing material 40'_1, and temporary fixing material 50'_2 is applied in the same position as temporary fixing material 40'_2.

[0050] Next, as shown in Figure 3D, the electronic component 30' is placed on the bonding material 10'. Note that the electronic component 30' is the same as the electronic component 30.

[0051] In the diagram, arrow A'_2 indicates the direction of movement of the electronic component 30' when it is placed on the bonding material 10'. In other words, arrow A'_2 indicates the direction of the force applied to the electronic component 30' when it is placed on the bonding material 10'.

[0052] At this time, the temporary fixing material 50' applied to the bonding material 10' spreads between the bonding material 10' and the electronic component 30'. This spread temporary fixing material 50' temporarily fixes the bonding material 10' and the electronic component 30' in place.

[0053] In this way, temporary fixing of the electronic circuit board 20' and the bonding material 10' is achieved, as is temporary fixing of the bonding material 10' and the electronic component 30'. As a result, temporary fixing of the electronic circuit board 20' and the electronic component 30' is achieved.

[0054] Next, unit U', which includes the bonding material 10', the electronic circuit board 20', the electronic component 30', the temporary fixing material 40', and the temporary fixing material 50', is placed in a reflow oven (not shown). Then, solder reflow is performed. Specifically, for example, reduction reflow using formic acid or hydrogen is performed. As a result, the solder constituting the bonding material 10' melts, and the electronic circuit board 20' and the electronic component 30' are joined.

[0055] Next, a modified example of the method for joining electronic components 30 to an electronic circuit board 20 using the bonding material 10 according to the first embodiment will be described. That is, a modified example of the method described with reference to Figures 2A to 2C will be described.

[0056] The step of applying the temporary fixing material 40 may be performed after the bonding material 10 is placed on the electronic circuit board 20, instead of before the bonding material 10 is placed on the electronic circuit board 20. In other words, in this case, the temporary fixing material 40 is applied to the bond material 10 that has been placed.

[0057] More specifically, temporary fixing material 40_1 is applied to the positions corresponding to the through holes 3_1. The applied temporary fixing material 40_1 penetrates into the individual first grooves 4_1 in the first plate surface 1. The applied temporary fixing material 40_1 also enters the through holes 3_1 and descends inside the through holes 3_1. The descended temporary fixing material 40_1 then penetrates into the individual second grooves 5_1 in the second plate surface 2.

[0058] Similarly, temporary fixing material 40_2 is applied to the positions corresponding to the through holes 3_2. The applied temporary fixing material 40_2 penetrates into each of the first grooves 4_2. The applied temporary fixing material 40_2 also enters the through holes 3_2 and descends inside the through holes 3_2. The descended temporary fixing material 40_2 then penetrates into each of the second grooves 5_2 in the second plate surface 2.

[0059] As a result, temporary fixing of the electronic circuit board 20 and the bonding material 10 is achieved, as well as temporary fixing of the bonding material 10 and the electronic component 30. In other words, temporary fixing of the electronic circuit board 20 and the electronic component 30 is achieved.

[0060] Next, a modified example of the joining material 10 will be described.

[0061] Firstly, the number of through-holes 3 in the base material 7 is not limited to two. The base material 7 only needs to have at least one through-hole 3. The number of through-holes 3 in the base material 7 may vary depending on the size of the bonding surface of the electronic component 30 (i.e., the size of the base material 7).

[0062] Secondly, the number of first grooves 4 communicating with each through-hole 3 is not limited to four. It is sufficient for at least one first groove 4 to communicate with each through-hole 3. However, increasing the number of first grooves 4 communicating with each through-hole 3 can increase the contact area of ​​the temporary fixing material 40 with respect to the electronic component 30. For this reason, the number of first grooves 4 communicating with each through-hole 3 may be set to different values ​​depending on the strength (i.e., contact area) required for temporary fixing.

[0063] Similarly, the number of second grooves 5 communicating with each through-hole 3 is not limited to four. It is sufficient for at least one second groove 5 to communicate with each through-hole 3. However, increasing the number of second grooves 5 communicating with each through-hole 3 can increase the contact area of ​​the temporary fixing material 40 with the electronic circuit board 20. For this reason, the number of second grooves 5 communicating with each through-hole 3 may be set to different values ​​depending on the strength (i.e., contact area) required for temporary fixing.

[0064] Thirdly, the shape and dimensions of each first groove 4 are not limited to the specific examples shown in Figures 1A to 1D. Each first groove 4 may have any shape and dimensions as long as the temporary fixing material 40 can penetrate through it.

[0065] In other words, the shape of each individual first groove 4 is not limited to being straight or substantially straight. For example, the shape of each individual first groove 4 may be curved or substantially curved. Or, for example, the shape of each individual first groove 4 may be wavy or substantially wavy. Or, for example, the shape of each individual first groove 4 may be U-shaped or substantially U-shaped.

[0066] Here, if the shape of each first groove 4 is U-shaped or substantially U-shaped, then in each first groove 4, the first end and the other end (hereinafter referred to as the "second end") may each communicate with the same through hole 3. In other words, both ends of each first groove 4 may communicate with the same through hole 3.

[0067] Similarly, the shape and dimensions of each second groove 5 are not limited to the specific examples shown in Figures 1A to 1D. Each second groove 5 may have any shape and dimensions as long as the temporary fixing material 40 can penetrate through it.

[0068] In other words, the shape of each second groove 5 is not limited to being straight or substantially straight. For example, the shape of each second groove 5 may be curved or substantially curved. Or, for example, the shape of each second groove 5 may be wavy or substantially wavy. Or, for example, the shape of each second groove 5 may be U-shaped or substantially U-shaped.

[0069] Here, if the shape of each second groove 5 is U-shaped or substantially U-shaped, then in each second groove 5, the first end and the other end (hereinafter referred to as the "second end") may each communicate with the same through hole 3. In other words, both ends of each second groove 5 may communicate with the same through hole 3.

[0070] Fourthly, the base material 7 may not have the second groove portion 5. In other words, the base material 7 may have only the first groove portion 4 of the first groove portion 4 and the second groove portion 5. In this case, the method of joining the electronic components 30 to the electronic circuit board 20 using the bonding material 10 is the same as that described with reference to Figures 2A to 2C. However, when the bonding material 10 is placed on the electronic circuit board 20, the temporary fixing material 40 spreads between the electronic circuit board 20 and the second plate surface portion 2 of the bonding material 10, instead of penetrating into the individual second groove portions 5. This achieves temporary fixing of the electronic circuit board 20 and the bonding material 10.

[0071] Even in this case, due to capillary action, the liquid temporary fixing material 40 enters each through-hole 3 and rises inside each through-hole 3. Then, the rising temporary fixing material 40 penetrates each first groove 4. As a result, temporary fixing of the bonding material 10 and the electronic component 30 is achieved.

[0072] Fifth, the bonding material 10 may be used with its front and back reversed. That is, in the example described with reference to Figures 2A to 2C, the first plate surface 1 is in contact with the electronic component 30, and the second plate surface 2 is in contact with the electronic circuit board 20. In contrast, the first plate surface 1 may be in contact with the electronic circuit board 20, and the second plate surface 2 may be in contact with the electronic component 30.

[0073] Next, the effects of the bonding material 10 will be explained.

[0074] As described above, the bonding material 10 is provided between the electronic circuit board 20 and the electronic component 30 when bonding the electronic component 30 to the electronic circuit board 20. The bonding material 10 comprises a plate-shaped base material 7. The bonding material 10 comprises at least one through hole 3 provided in the base material 7, into which the liquid temporary fixing material 40 enters. The bonding material 10 comprises a first groove 4 provided on the surface portion (first plate surface portion 1) of the base material 7 and communicating with the through hole 3, into which the temporary fixing material 40 penetrates.

[0075] As the temporary fixing material 40 enters the through hole 3 and penetrates the first groove 4, the following temporary fixing is achieved: that is, temporary fixing is achieved between the joining material 10 and the member (e.g., electronic component 30) provided on the first plate surface 1, and temporary fixing is achieved between the joining material 10 and the member (e.g., electronic circuit board 20) provided on the second plate surface 2.

[0076] Here, the presence of the first groove 4 increases the contact area between the temporary fixing material 40 and the member (e.g., electronic component 30) placed on the first plate surface 1, compared to the case where a groove corresponding to the first groove 4 is not provided. This makes it possible to strengthen the temporary fixing between the temporary fixing material 40 and the member. In particular, it is possible to strengthen the temporary fixing against rotational forces along the plate surface of the electronic circuit board 20. This is an advantageous effect compared to the technology described in Patent Document 1.

[0077] As a result, sufficient temporary fixing strength can be achieved against forces generated by the process of placing the member on the bonding material 10, or forces generated by vibrations when the unit U is transported. Therefore, for example, the occurrence of misalignment of the electronic component 30 relative to the electronic circuit board 20 can be suppressed. As a result, variations in the quality of electronic equipment caused by misalignment can be reduced.

[0078] Furthermore, by using the bonding material 10, the number of steps required to apply the temporary fixing material 40 can be reduced compared to the case where bonding material 10' is used. That is, when bonding material 10' is used, as explained with reference to Figures 3A to 3E, both the step of applying the temporary fixing material 40' to the electronic circuit board 20' and the step of applying the temporary fixing material 50' to the bonding material 10' are required. The requirement for both of these steps resulted in a time-consuming process. In contrast, when bonding material 10 is used, as described above, only one of the steps of applying the temporary fixing material 40 to the electronic circuit board 20 or applying the temporary fixing material 40 to the bonding material 10 is required. This is because, as described above, the temporary fixing material 40 enters each through-hole 3 due to capillary action.

[0079] By reducing the number of steps required to apply the temporary fixing material 40, the time required for assembling unit U can be shortened. Furthermore, the manufacturing cost of unit U can be reduced. As a result, the manufacturing cost of electronic devices using unit U can be reduced.

[0080] Furthermore, by using the bonding material 10, the following advantageous effects are obtained compared to the technology described in Patent Document 2. That is, the technology described in Patent Document 2 is a method of transferring a temporary fixing material (more specifically, flux) to a surface mount component using a suction nozzle in a so-called "transfer method" (see, for example, paragraph

[0059] and Figure 9(3) of Patent Document 2). Hereinafter, this method will be referred to as the "method of Patent Document 2".

[0081] The method described in Patent Document 2 cannot be used if the suction force of the suction nozzle is inferior to the adhesive force of the temporary fixing material used during transfer. In other words, the method described in Patent Document 2 had the problem that it could not be used depending on the suction force of the suction nozzle used for transfer.

[0082] Furthermore, the method described in Patent Document 2 cannot be used when it is not possible to adsorb the upper surface (i.e., top surface) of a surface-mount component using a suction nozzle. For example, if the surface-mount component is a bare chip for face-up mounting, the semiconductor chip is exposed to the outside on the upper surface of the surface-mount component because the surface-mount component is unsealed. Therefore, it is not possible to adsorb the upper surface of the surface-mount component using a suction nozzle. Consequently, there was a problem in that the method described in Patent Document 2 could not be used.

[0083] In contrast, when using the bonding material 10, it is unnecessary to use a suction nozzle to pick up the electronic component 30. In other words, a suction nozzle is not required. Therefore, these problems can be avoided. That is, for example, even if the electronic component 30 is made up of a bare chip for face-up mounting, the above-described temporary fixing can be achieved. Furthermore, the above-described bonding can be achieved.

[0084] Next, we will explain the other effects of the bonding material 10.

[0085] The bonding material 10 is provided on the back surface (second plate surface 2) of the base material 7 and has a second groove 5 that communicates with the through hole 3, through which the temporary fixing material 40 penetrates. This allows for temporary fixing of the bonding material 10 to a member (e.g., an electronic circuit board 20) provided on the second plate surface 2 by the same action as temporary fixing of the bonding material 10 to a member (e.g., an electronic component 30) provided on the first plate surface 1. Furthermore, the bonding material 10 can be used with its front and back sides reversed.

[0086] The joining material 10 is provided with a plurality of first grooves 4 arranged radially with respect to the through hole 3. By providing a plurality of first grooves 4, the strength of the temporary fixation can be further improved compared to the case where there is only one first groove 4.

[0087] The joining material 10 is provided with multiple second grooves 5 arranged radially with respect to the through hole 3. By providing multiple second grooves 5, the strength of the temporary fixation can be further improved compared to the case where there is only one second groove 5.

[0088] The through-hole 3 includes a first through-hole (through-hole 3_1) and a second through-hole (through-hole 3_2). The joining material 10 has at least one first groove 4 that communicates with the first through-hole (through-hole 3_1). The joining material 10 has at least one other first groove 4 that communicates with the second through-hole (through-hole 3_2). By providing multiple through-holes 3, the strength of the temporary fixation can be further improved compared to the case where there is only one through-hole 3.

[0089] The through-hole 3 includes a first through-hole (through-hole 3_1) and a second through-hole (through-hole 3_2). The joining material 10 has at least one second groove 5 that communicates with the first through-hole (through-hole 3_1). The joining material 10 also has at least one other second groove 5 that communicates with the second through-hole (through-hole 3_2). By providing multiple through-holes 3, the strength of the temporary fixation can be further improved compared to the case where there is only one through-hole 3.

[0090] The bonding material 10 is made of solder. The temporary fixing material 40 is made of a volatile resin that volatilizes upon heating during solder reflow, or a thermosetting resin that hardens upon heating. By using a volatile resin or a thermosetting resin in the temporary fixing material 40, strong temporary fixing can be achieved as described above. [Second Embodiment] Figure 4A is a plan view of the joint according to the second embodiment. Figure 4B is a bottom view of the joint according to the second embodiment. Figure 4C is a cross-sectional view along the line A2-A2 shown in Figures 4A and 4B. Figure 4D is a cross-sectional view along the line B2-B2 shown in Figures 4A and 4B. The joint according to the second embodiment will be described with reference to Figures 4A to 4D. In Figures 4A to 4D, elements similar to those shown in Figures 1A to 1D are denoted by the same reference numerals and their descriptions are omitted.

[0091] As shown in Figures 4A to 4D, the joining material 10a comprises a base material 7 similar to that of the joining material 10. That is, the joining material 10a comprises a plate-shaped base material 7.

[0092] The base material 7 has at least one through hole 3a formed therein. Specifically, for example, two through holes 3a_1 and 3a_2 are formed therein.

[0093] Here, multiple grooves (hereinafter referred to as "third grooves") 6 are formed on the inner circumference of each through-hole 3a. Each third groove 6 has a longitudinal direction along the through-direction of each through-hole 3a in the plate-shaped base material 7. In other words, each third groove 6 is a so-called "longitudinal groove". To put it another way, multiple longitudinal grooves are formed on the inner circumference of each through-hole 3a.

[0094] In the examples shown in Figures 4A to 4D, eight third grooves 6_1 are formed on the inner circumference of the through hole 3a_1. The eight third grooves 6_1 are arranged at equal or approximately equal intervals from one another. As shown in Figures 4A and 4B, each third groove 6_1 has a V-shaped or approximately V-shaped cross-section. As a result, the cross-sectional shape of the through hole 3a_1 is a star-shaped octagon or approximately a star-shaped octagon. That is, the shape of the through hole 3a_1 is a star-shaped octagonal prism or approximately a star-shaped octagonal prism.

[0095] In the examples shown in Figures 4A to 4D, eight third grooves 6_2 are formed on the inner circumference of the through hole 3a_2. The eight third grooves 6_2 are arranged at equal or approximately equal intervals from one another. As shown in Figures 4A and 4B, each third groove 6_2 has a V-shaped or approximately V-shaped cross-section. As a result, the cross-sectional shape of the through hole 3a_2 is a star-shaped regular octagon or approximately a star-shaped regular octagon. That is, the shape of the through hole 3a_2 is a star-shaped regular octagonal prism or approximately a star-shaped regular octagonal prism.

[0096] In this way, the main part of the joining material 10a is constructed.

[0097] The method for joining the electronic component 30 to the electronic circuit board 20 using the bonding material 10a is the same as that described in the first embodiment with reference to Figures 2A to 2C. Therefore, a further explanation will be omitted.

[0098] Furthermore, the bonding material 10a can be modified in various ways similar to those described in the first embodiment. Further explanation of these modifications will be omitted.

[0099] By using the bonding material 10a, various effects similar to those described in the first embodiment can be obtained. Further explanation of these effects will be omitted.

[0100] In addition, the following effects can be obtained by using the bonding material 10a.

[0101] As described above, the joining material 10a is provided with a plurality of third grooves 6 on the inner circumference of the through hole 3a. Each of the plurality of third grooves 6 has a longitudinal direction along the through-direction of the through hole 3a.

[0102] In other words, multiple vertical grooves are formed on the inner circumference of the through-hole 3a. The formation of multiple vertical grooves facilitates the upward movement of the liquid temporary fixing material 40 as it rises through the interior of each through-hole 3a by capillary action. As a result, the temporary fixing material 40 can be easily permeated into each of the first grooves 4. [Third Embodiment] Figure 5A is a plan view of the joint according to the third embodiment. Figure 5B is a bottom view of the joint according to the third embodiment. Figure 5C is a cross-sectional view along the line A3-A3 shown in Figures 5A and 5B. Figure 5D is a cross-sectional view along the line B3-B3 shown in Figures 5A and 5B. The joint according to the third embodiment will be described with reference to Figures 5A to 5D. In Figures 5A to 5D, elements similar to those shown in Figures 1A to 1D are denoted by the same reference numerals and their descriptions are omitted.

[0103] As shown in Figures 5A to 5D, the joining material 10b comprises a base material 7 similar to that of the joining material 10. That is, the joining material 10b comprises a plate-shaped base material 7.

[0104] The first plate surface portion 1 of the base material 7 has at least one first groove portion 4b that communicates with each through hole 3. Specifically, for example, as shown in Figure 5A, four first groove portions 4b_1_1 to 4b_1_4 are formed that communicate with the through hole 3_1. In addition, four first groove portions 4b_2_1 to 4b_2_4 are formed that communicate with the through hole 3_2.

[0105] The second plate surface portion 2 of the base material 7 has at least one second groove portion 5b that communicates with each through hole 3. Specifically, for example, as shown in Figure 5B, four second groove portions 5b_1_1 to 5b_1_4 are formed that communicate with the through hole 3_1. In addition, four second groove portions 5b_2_1 to 5b_2_4 are formed that communicate with the through hole 3_2.

[0106] Here, as shown in Figures 5C and 5D, each first groove 4b has a V-shaped or roughly V-shaped cross-section. Similarly, each second groove 5b has a V-shaped or roughly V-shaped cross-section. Hereafter, a V-shaped or roughly V-shaped cross-section may be referred to as a "V-shaped cross-section."

[0107] In this way, the main part of the joining material 10b is constructed.

[0108] The method for joining the electronic components 30 to the electronic circuit board 20 using the bonding material 10b is the same as that described in the first embodiment with reference to Figures 2A to 2C. Therefore, a further explanation will be omitted.

[0109] Furthermore, the bonding material 10b can be modified in various ways similar to those described in the first embodiment. Further explanation of these modifications will be omitted.

[0110] By using the bonding material 10b, various effects similar to those described in the first embodiment can be obtained. Further explanation of these effects will be omitted.

[0111] In addition, the following effects can be obtained by using the bonding material 10b.

[0112] In other words, the shape of the first groove 4b is V-shaped in cross-section. This makes it easier for the liquid temporary fixing material 40 to permeate each of the first grooves 4b.

[0113] Furthermore, the shape of the second groove 5b is V-shaped in cross-section. This makes it easier for the liquid temporary fixing material 40 to permeate each of the second grooves 5b.

[0114] The joining material 10b may also have through holes 3a instead of individual through holes 3. That is, the joining material 10b may have multiple third grooves 6 on the inner circumference of each through hole 3a. [Fourth Embodiment] Figure 6A is a plan view of the joint according to the fourth embodiment. Figure 6B is a bottom view of the joint according to the fourth embodiment. Figure 6C is a cross-sectional view along the line A4-A4 shown in Figures 6A and 6B. Figure 6D is a cross-sectional view along the line B4-B4 shown in Figures 6A and 6B. The joint according to the fourth embodiment will be described with reference to Figures 6A to 6D. In Figures 6A to 6D, elements similar to those shown in Figures 1A to 1D are denoted by the same reference numerals and their descriptions are omitted.

[0115] As shown in Figures 6A to 6D, the joining material 10c comprises a base material 7 similar to that of the joining material 10. That is, the joining material 10c comprises a plate-shaped base material 7.

[0116] The first plate surface portion 1 of the base material 7 has at least one first groove portion 4c that communicates with each individual through hole 3. Specifically, for example, as shown in Figure 6A, four first groove portions 4c_1_1 to 4c_1_4 are formed that communicate with the through hole 3_1. In addition, four first groove portions 4c_2_1 to 4c_2_4 are formed that communicate with the through hole 3_2.

[0117] The second plate surface portion 2 of the base material 7 has at least one second groove portion 5c that communicates with each through hole 3. Specifically, for example, as shown in Figure 6B, four second groove portions 5c_1_1 to 5c_1_4 are formed that communicate with the through hole 3_1. In addition, four second groove portions 5c_2_1 to 5c_2_4 are formed that communicate with the through hole 3_2.

[0118] Here, as shown in Figures 6C and 6D, each first groove 4c_1 has a tapered bottom. As a result, the depth of each first groove 4c_1 gradually decreases as it moves away from the through hole 3_1 along its longitudinal direction. Similarly, each first groove 4c_2 has a tapered bottom. As a result, the depth of each first groove 4c_2 gradually decreases as it moves away from the through hole 3_2 along its longitudinal direction. In other words, the bottom of each first groove 4c slopes upward when viewed from the connecting through hole 3.

[0119] Furthermore, as shown in Figures 6C and 6D, each second groove 5c_1 has a tapered bottom. As a result, the depth of each second groove 5c_1 gradually decreases as it moves away from the through hole 3_1 along its longitudinal direction. Similarly, each second groove 5c_2 has a tapered bottom. As a result, the depth of each second groove 5c_2 gradually decreases as it moves away from the through hole 3_2 along its longitudinal direction. In other words, the bottom of each second groove 5c slopes upward when viewed from the connecting through hole 3.

[0120] In this way, the main part of the joining material 10c is constructed.

[0121] The method for joining the electronic components 30 to the electronic circuit board 20 using the bonding material 10c is the same as that described in the first embodiment with reference to Figures 2A to 2C. Therefore, a further explanation will be omitted.

[0122] Furthermore, the bonding material 10c can be modified in various ways similar to those described in the first embodiment. Further explanation of these modifications will be omitted.

[0123] By using the bonding material 10c, various effects similar to those described in the first embodiment can be obtained. Further explanation of these effects will be omitted.

[0124] In addition, by using the bonding material 10c, the following effects can be obtained.

[0125] In other words, one end (first end) of the first groove 4c is in communication with the through hole 3. Because the bottom of the first groove 4c is tapered, the depth of the first groove 4c gradually decreases as it moves away from the through hole 3.

[0126] As described in the first embodiment, the liquid temporary fixing material 40 rises inside each through hole 3 by capillary action. The rising temporary fixing material 40 penetrates into each first groove 4c. At this time, because each first groove 4c has a shape that becomes progressively shallower as it moves away from the through hole 3, capillary action also occurs in each first groove 4c. As a result, the temporary fixing material 40 moves more easily in each first groove 4c in the direction away from the communicating through hole 3. Therefore, it is possible to easily penetrate the temporary fixing material 40 into each first groove 4c. As a result, the temporary fixing between the joining material 10c and the member (for example, electronic component 30) provided on the first plate surface 1 can be made even stronger.

[0127] Furthermore, one end (the first end) of the second groove 5c is in communication with the through hole 3. Because the bottom of the second groove 5c is tapered, the depth of the second groove 5c gradually decreases as it moves away from the through hole 3.

[0128] As described in the first embodiment, the bonding material 10c may be used with its front and back reversed. In this case, the temporary fixing material 40 that rises inside each through hole 3 penetrates into each second groove 5c. At this time, because each second groove 5c has a shape that becomes progressively shallower as it moves away from the through hole 3, capillary action occurs in each second groove 5c as well. As a result, the temporary fixing material 40 moves more easily in each second groove 5c in the direction away from the communicating through hole 3. Therefore, it is possible to make it easier for the temporary fixing material 40 to penetrate into each second groove 5c. As a result, the temporary fixing between the bonding material 10c and the member (for example, electronic component 30) provided on the second plate surface 2 can be made even stronger.

[0129] The joining material 10c may also have through holes 3a instead of individual through holes 3. That is, the joining material 10c may have multiple third grooves 6 on the inner circumference of each through hole 3a.

[0130] Furthermore, each first groove 4c may have a V-shaped or roughly V-shaped cross-section. Each second groove 5c may also have a V-shaped or roughly V-shaped cross-section. [Fifth Embodiment] Figure 7A is a plan view of the joint according to the fifth embodiment. Figure 7B is a bottom view of the joint according to the fifth embodiment. Figure 7C is a cross-sectional view along the line A5-A5 shown in Figures 7A and 7B. Figure 7D is a cross-sectional view along the line B5-B5 shown in Figures 7A and 7B. The joint according to the fifth embodiment will be described with reference to Figures 7A to 7D. In Figures 7A to 7D, elements similar to those shown in Figures 1A to 1D are denoted by the same reference numerals and their descriptions are omitted.

[0131] As shown in Figures 7A to 7D, the joining material 10d comprises a base material 7 similar to that of the joining material 10; that is, the joining material 10d comprises a plate-shaped base material 7.

[0132] The first plate surface portion 1 of the base material 7 has at least one first groove portion 4d that communicates with each through hole 3. Specifically, for example, as shown in Figure 7A, four first groove portions 4d_1_1 to 4d_1_4 are formed that communicate with the through hole 3_1. In addition, four first groove portions 4d_2_1 to 4d_2_4 are formed that communicate with the through hole 3_2.

[0133] The second plate surface portion 2 of the base material 7 has at least one second groove portion 5d that communicates with each through hole 3. Specifically, for example, as shown in Figure 7B, four second groove portions 5d_1_1 to 5d_1_4 are formed that communicate with the through hole 3_1. In addition, four second groove portions 5d_2_1 to 5d_2_4 are formed that communicate with the through hole 3_2.

[0134] Here, as shown in Figures 7C and 7D, each first groove 4d_1 has a tapered bottom. As a result, the depth of each first groove 4d_1 gradually increases as it moves away from the through hole 3_1 along its longitudinal direction. Similarly, each first groove 4d_2 has a tapered bottom. As a result, the depth of each first groove 4d_2 gradually increases as it moves away from the through hole 3_2 along its longitudinal direction. In other words, the bottom of each first groove 4d slopes downward when viewed from the communicating through hole 3.

[0135] Furthermore, as shown in Figures 7C and 7D, each second groove 5d_1 has a tapered bottom. As a result, the depth of each second groove 5d_1 gradually increases as it moves away from the through hole 3_1 along its longitudinal direction. Similarly, each second groove 5d_2 has a tapered bottom. As a result, the depth of each second groove 5d_2 gradually increases as it moves away from the through hole 3_2 along its longitudinal direction. In other words, the bottom of each second groove 5d slopes downward when viewed from the communicating through hole 3.

[0136] In this way, the main part of the joining material 10d is constructed.

[0137] The method for joining the electronic component 30 to the electronic circuit board 20 using the bonding material 10d is the same as that described in the first embodiment with reference to Figures 2A to 2C. Therefore, a further explanation will be omitted.

[0138] Furthermore, the bonding material 10d can be modified in various ways similar to those described in the first embodiment. Further explanation of these modifications will be omitted.

[0139] By using the bonding material 10d, various effects similar to those described in the first embodiment can be obtained. Further explanation of these effects will be omitted.

[0140] In addition, by using the bonding material 10d, the following effects can be obtained.

[0141] In other words, one end (first end) of the first groove 4d is in communication with the through hole 3. Because the bottom of the first groove 4d is tapered, the depth of the first groove 4d gradually increases as it moves away from the communicating through hole 3.

[0142] As described in the first embodiment, the liquid temporary fixing material 40 rises inside each through-hole 3 by capillary action. The rising temporary fixing material 40 penetrates into each first groove 4d. At this time, because each first groove 4d has a shape that gradually deepens as it moves away from the through-hole 3, capillary action also occurs in each first groove 4d. As a result, the temporary fixing material 40 tends to accumulate in the area near the connecting through-hole 3 in each first groove 4d. This makes it easier to supply the temporary fixing material 40 above the joining material 10d. In other words, the amount of temporary fixing material 40 supplied above the joining material 10d can be increased.

[0143] Furthermore, one end (first end) of the second groove 5d is in communication with the through hole 3. Because the bottom of the second groove 5d is tapered, the depth of the second groove 5d gradually increases as it moves away from the through hole 3.

[0144] As described in the first embodiment, the joining material 10d may be used with its front and back reversed. In this case, the temporary fixing material 40 that rises inside each through hole 3 penetrates into each second groove 5d. At this time, because each second groove 5d has a shape that gradually deepens as it moves away from the through hole 3, capillary action occurs in each second groove 5d as well. As a result, the temporary fixing material 40 tends to accumulate in the area near the communicating through hole 3 in each second groove 5d. This makes it easier to supply the temporary fixing material 40 to the upper part of the joining material 10d. In other words, the amount of temporary fixing material 40 supplied to the upper part of the joining material 10d can be increased.

[0145] The joining material 10d may also have through holes 3a instead of individual through holes 3. That is, the joining material 10d may have multiple third grooves 6 on the inner circumference of each through hole 3a.

[0146] Furthermore, each first groove 4d may have a V-shaped or roughly V-shaped cross-section. Each second groove 5d may also have a V-shaped or roughly V-shaped cross-section. [Sixth Embodiment] Figure 8A is a plan view of the joint according to the sixth embodiment. Figure 8B is a bottom view of the joint according to the sixth embodiment. Figure 8C is a cross-sectional view along the line A6-A6 shown in Figures 8A and 8B. Figure 8D is a cross-sectional view along the line B6-B6 shown in Figures 8A and 8B. The joint according to the sixth embodiment will be described with reference to Figures 8A to 8D. In Figures 6A to 8D, elements similar to those shown in Figures 1A to 1D are denoted by the same reference numerals and their descriptions are omitted.

[0147] As shown in Figures 8A to 8D, the joining material 10e comprises a plate-shaped base material 7. The base material 7 has at least one through hole 3. The base material 7 also has at least one first groove 4 that communicates with each through hole 3. However, the base material 7 does not have a second groove 5. Even in this case, the same effects as those described in the first embodiment can be obtained. This is as explained in the first embodiment.

[0148] In other words, the bonding material 10e is provided between the electronic circuit board 20 and the electronic component 30 when bonding the electronic component 30 to the electronic circuit board 20. The bonding material 10e comprises a plate-shaped base material 7. The bonding material 10e comprises at least one through hole 3 provided in the base material 7, into which the liquid temporary fixing material 40 enters. The bonding material 10e comprises a first groove 4 provided on the surface portion (first plate surface portion 1) of the base material 7 and communicating with the through hole 3, into which the temporary fixing material 40 penetrates.

[0149] The presence of the first groove 4 increases the contact area between the temporary fixing material 40 and the member (e.g., electronic component 30) placed on the first plate surface 1, compared to the case where a groove corresponding to the first groove 4 is not provided. This strengthens the temporary fixing between the temporary fixing material 40 and the member. As a result, sufficient strength can be achieved in temporary fixing against forces applied to the electronic circuit board 20 or electronic component 30 before joining after temporary fixing.

[0150] Although the present disclosure has been described above with reference to embodiments, the present disclosure is not limited to the embodiments described above. Various modifications to the structure and details of the present disclosure may be made that can be understood by those skilled in the art within the scope of the present disclosure.

[0151] Some or all of the above embodiments may also be described as follows, but are not limited to the following: [Note] [Note 1] When joining electronic components to an electronic circuit board, a bonding material is provided between the electronic circuit board and the electronic components, A plate-shaped base material, At least one through-hole provided in the substrate, the through-hole into which a liquid temporary fixing material is inserted, A first groove provided on the surface of the substrate and communicating with the through hole, the first groove through which the temporary fixing material penetrates, A bonding material equipped with the following features.

[0152] [Note 2] The joining material according to Appendix 1, characterized in that the shape of the first groove is V-shaped in cross-section.

[0153] [Note 3] One end of the first groove is in communication with the through hole, Because the bottom of the first groove is tapered, the depth of the first groove gradually decreases as it moves away from the communicating through hole. The bonding material described in Appendix 1 or Appendix 2, characterized by the above.

[0154] [Note 4] One end of the first groove is in communication with the through hole, Because the bottom of the first groove is tapered, the depth of the first groove gradually increases as it moves away from the communicating through hole. The bonding material described in Appendix 1 or Appendix 2, characterized by the above.

[0155] [Note 5] The joining material according to any one of the appendices 1 to 4, characterized in that it comprises a second groove provided on the back surface of the base material and communicating with the through hole, through which the temporary fixing material penetrates.

[0156] [Note 6] The joining material according to Appendix 5, characterized in that the shape of the second groove is V-shaped in cross-section.

[0157] [Note 7] One end of the second groove is in communication with the through hole, Because the bottom of the second groove is tapered, the depth of the second groove gradually decreases as it moves away from the through hole through which it communicates. The bonding material described in Appendix 5 or Appendix 6, characterized by the features described herein.

[0158] [Note 8] One end of the second groove is in communication with the through hole, Because the bottom of the second groove is tapered, the depth of the second groove gradually increases as it moves away from the through hole that it communicates with. The bonding material described in Appendix 5 or Appendix 6, characterized by the features described herein.

[0159] [Note 9] The through hole is provided with a plurality of third grooves on its inner circumference, Each of the multiple third grooves has a longitudinal direction along the through-hole's penetration direction. A bonding material characterized by any one of the appendices 1 to 8.

[0160] [Note 10] The joining material according to any one of the appendices 1 to 8, characterized by comprising a plurality of first grooves arranged radially with respect to the through hole.

[0161] [Note 11] The joining material according to any one of the appendices 5 to 8, characterized by comprising a plurality of second grooves arranged radially with respect to the through hole.

[0162] [Note 12] The aforementioned through-holes include a first through-hole and a second through-hole, At least one of the first grooves communicating with the first through hole, The first groove comprises at least one other groove communicating with the second through hole. A bonding material characterized by any one of the appendices 1 to 8.

[0163] [Note 13] The aforementioned through-holes include a first through-hole and a second through-hole, At least one of the second grooves communicating with the first through hole, The second groove comprises at least one other groove communicating with the second through hole. A bonding material characterized by any one of the appendices 5 to 8.

[0164] [Note 14] The joining material according to any one of the appendices 1 to 4, characterized in that the temporary fixing material enters the through hole and penetrates the first groove, thereby achieving temporary fixing of the electronic circuit board and the electronic component.

[0165] [Note 15] The joining material according to any one of the appendices 5 to 8, characterized in that the temporary fixing material enters the through hole and penetrates the first groove and the second groove, thereby achieving temporary fixing of the electronic circuit board and the electronic component.

[0166] [Note 16] The aforementioned substrate is made using solder, The temporary fixing material is made of a volatile resin that volatilizes upon heating during solder reflow, or a thermosetting resin that hardens upon heating. A bonding material characterized by any one of the appendices 1 to 15.

[0167] [Note 17] A temporary fixing method for temporarily fixing an electronic circuit board and an electronic component when joining the electronic component to the electronic circuit board, A step of placing a plate-shaped bonding material at the position where the electronic components are bonded on the electronic circuit board, The process involves filling the through-hole of the aforementioned joining material with a liquid temporary fixing material, The process includes placing the electronic component on the bonding material, A first groove is provided on the surface of the joining material that communicates with the through hole. The temporary fixing material penetrates into the first groove. A temporary fixing method characterized by the following:

[0168] [Note 18] A method for manufacturing an electronic device comprising an electronic circuit board and electronic components bonded to the electronic circuit board, A step of placing a plate-shaped bonding material at the position where the electronic components are bonded on the electronic circuit board, The process involves filling the through-hole of the aforementioned joining material with a liquid temporary fixing material, The process includes placing the electronic component on the bonding material, A first groove is provided on the surface of the joining material that communicates with the through hole. The temporary fixing material penetrates into the first groove. A manufacturing method characterized by the following features. [Explanation of Symbols]

[0169] 1 1st plate surface part (surface part) 2 2nd plate surface section (back surface section) 3,3a through hole 4,4b,4c,4d 1st groove 5,5b,5c,5d 2nd groove 6. Third groove 7 Base material 10, 10a, 10b, 10c, 10d, 10e Joining material 20 Electronic circuit boards 30 Electronic Components 40 Temporary fixing material

Claims

1. When joining electronic components to an electronic circuit board, a bonding material is provided between the electronic circuit board and the electronic components, A plate-shaped base material, At least one through-hole provided in the substrate, the through-hole into which a liquid temporary fixing material is inserted, A first groove is provided on the surface portion of the substrate on which the electronic component is placed, and is in communication with the through hole, and the first groove through which the temporary fixing material penetrates, A bonding material equipped with the following features.

2. The joining material according to claim 1, characterized in that the shape of the first groove is V-shaped in cross-section.

3. One end of the first groove is in communication with the through hole, Because the bottom of the first groove is tapered, the depth of the first groove gradually decreases as it moves away from the through hole that it communicates with. The bonding material according to claim 1 or 2.

4. One end of the first groove is in communication with the through hole, Because the bottom of the first groove is tapered, the depth of the first groove gradually increases as it moves away from the connecting through hole. The bonding material according to claim 1 or 2.

5. The bonding material according to any one of claims 1 to 4, characterized in that it comprises a second groove provided on the back surface of the substrate that contacts the electronic circuit board, and which communicates with the through hole, and through which the temporary fixing material penetrates.

6. The joining material according to claim 5, characterized in that the shape of the second groove is V-shaped in cross-section.

7. One end of the second groove is in communication with the through hole, Because the bottom of the second groove is tapered, the depth of the second groove gradually decreases as it moves away from the through hole through which it communicates. The bonding material according to claim 5 or 6, characterized by the features described above.

8. One end of the second groove is in communication with the through hole, Because the bottom of the second groove is tapered, the depth of the second groove gradually increases as it moves away from the through hole that it communicates with. The bonding material according to claim 5 or 6, characterized by the features described above.

9. A temporary fixing method for temporarily fixing an electronic circuit board and an electronic component when joining the electronic component to the electronic circuit board, A step of placing a plate-shaped bonding material at the position where the electronic components are bonded on the electronic circuit board, The process involves filling the through-hole of the aforementioned joining material with a liquid temporary fixing material, The process includes placing the electronic component on the bonding material, A first groove communicating with the through hole is provided on the surface portion of the bonding material on which the electronic component is placed. The temporary fixing material penetrates the first groove. A temporary fixing method characterized by the following:

10. A method for manufacturing an electronic device comprising an electronic circuit board and electronic components bonded to the electronic circuit board, A step of placing a plate-shaped bonding material at the position where the electronic components are bonded on the electronic circuit board, The process involves filling the through-hole of the aforementioned joining material with a liquid temporary fixing material, The process includes placing the electronic component on the bonding material, A first groove communicating with the through hole is provided on the surface portion of the bonding material on which the electronic component is placed. The temporary fixing material penetrates the first groove. A manufacturing method characterized by the following features.

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