JP2019161024A - Bonding material, bonding structure, forming method, and manufacturing method - Google Patents

Abstract

To provide a bonding material that can suppress breakage and improve yield when bonding two electrodes.SOLUTION: The bonding material includes a plurality of conductive wires and a resin. Each of the conductive wires is accommodated in a predetermined closed curved surface. A first end of the conductive wire is exposed from a first region of the closed curved surface and a second end of the conductive wire is exposed from a second region of the closed curved surface. A length of the conductive wire is longer than a distance between the first region and the second region. The resin is accommodated in the closed curved surface and is a solid or close to a solid.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a structure for joining an electronic component to a circuit board.

  BGA which is one form of the external electrode of the semiconductor component is arranged in an area array of solder balls at the electrode position of the circuit board on the lower surface of the semiconductor component, and the solder balls are melted by a reflow process to be joined to the circuit board. Take electrical continuity. Here, BGA is an abbreviation for Ball Grid Array. Compared to the shape in which the external electrodes are arranged outside the external shape of the component using leads, such as DIP and QFP, the connection between the circuit board and the component has the advantage that the component mounting area can be reduced even with the same number of pins. Therefore, the adoption is expanding. Here, DIP is an abbreviation for Dual Inline Package. QFP is an abbreviation for Quad Flat Package.

  However, in general BGA bonding, distortion generated due to the difference in thermal expansion between the package and the circuit board is repeatedly generated in the BGA bonding portion due to heat generated during the operation of the semiconductor component, etc., and cracks are generated in the BGA bonding portion. May cause fatigue failure.

  In order to solve this problem, Patent Document 1 discloses a method of compressing and interposing a conductive column processed into a spring shape instead of a solder bump. Patent Documents 2 and 3 disclose bonding materials using stranded wires and knitted wires made of a plurality of wires.

Japanese Patent Laid-Open No. 08-139226 JP 2009-224682 A JP 09-307053 A

  In the method disclosed in Patent Document 1, the spring-like member used in place of the BGA solder ball is composed of a single member, so that there is a risk of cracks occurring due to repeated strain over a long period of time and breaking. .

  On the other hand, in the methods disclosed in Patent Documents 2 and 3, there is a high probability that a plurality of wire rods included in the bonding material are unwound from each other in the process of bonding two electrodes with the bonding material. Therefore, this method has a poor yield related to the bonding.

  An object of this invention is to provide the joining material etc. which can suppress a fracture | rupture and can improve the yield at the time of joining two electrodes.

  The bonding material of the present invention includes a plurality of conducting wires and a resin, each of the conducting wires is accommodated in a predetermined closed curved surface, and a first end portion of the conducting wire is exposed from a first region of the closed curved surface, The second end of the conducting wire is exposed from the second region of the closed surface, the length of the conducting wire is longer than the distance between the first region and the second region, the resin is accommodated in the closed surface, Solid or near solid.

  The bonding material of the present invention can suppress breakage, and can improve the yield when bonding two electrodes.

It is an image figure showing the example (the 1) of the joining material of this embodiment. It is an image figure showing the example (the 2) of the joining material of this embodiment. It is an image figure showing the example (the 3) of the joining material of this embodiment. It is an image figure showing the example (the 4) of the joining material of this embodiment. It is a figure showing a mode that an electronic component is joined to a circuit board using a joining material. It is a figure showing the example of the conjugate | zygote of this embodiment. It is an image figure showing the joined body which the circuit board thermally expanded. It is an image figure showing the example of the manufacturing method of a joining material (the 1). It is an image figure showing the example of the manufacturing method of a joining material (the 2). It is a block diagram showing the minimum composition of the joining material of an embodiment.

[Configuration and operation]
FIG. 1 is an image diagram showing a bonding material 101 which is an example of the bonding material of the present embodiment. Note that the bonding material 101 illustrated in FIG. 1 is merely an image, and does not correctly represent the configuration of the bonding material 101. Hereinafter, the “image diagram” refers to the above diagram.

  FIG. 1A is an image view of a side surface of the bonding material 101. FIG. 1B is an image view of a cross section of the bonding material 101. FIG. 1A and FIG. 1B do not correspond to each other.

  The bonding material 101 includes a conductive wire group 106 and a resin 111.

  Each conducting wire group 106 is formed by braiding a plurality of conducting wires 116 having a substantially circular cross section. That is, the conducting wire group 106 is a braided bundle formed so that a plurality of conducting wires cross like a stitch. The material of the conducting wire 116 is arbitrary as long as it has conductivity, and is, for example, copper. In addition, the number of conducting wires is arbitrary and may not be the number shown in FIG.

  The upper end portion of each of the conductive wires 116 is exposed from the upper region of the resin 111 according to the view shown in FIG. Moreover, the lower end part of each conducting wire 116 is exposed from the lower region of the resin 111 according to the view shown in FIG.

  The resin 111 is formed so as to enter between the conductors 116 around the conductor group 106 and inside the conductor group 106. Each of the conductive wires 116 is hardened to some extent by the resin 111 and is difficult to unwind. The resin 111 is a solid or a fluid close to a solid having a certain degree of viscosity.

  The resin 111 may be a conductive resin. When the resin 111 is a conductive resin, the electrical resistance between the upper and lower ends shown in FIG.

  FIG. 2 is an image diagram showing a bonding material 101 which is a second example of the bonding material of the present embodiment. The description of the bonding material 101 illustrated in FIG. 2 is the same as the description of the bonding material 101 illustrated in FIG. 1 except that there are three types of conductors having different thicknesses. However, when the above description and the description of FIG.

  FIG. 3 is an image diagram showing a bonding material 101 which is a third example of the present embodiment.

  The plurality of conducting wires 116 shown in FIG. 3 are twisted together like a lead pin described in Patent Document 3, for example, without crossing each other like the conducting wires 116 shown in FIG. Except for the above, the description of the bonding material 101 illustrated in FIG. 3 is the same as the description of the bonding material 101 illustrated in FIG. 1. However, when the above description and the description of FIG.

  FIG. 4 is an image diagram showing a bonding material 101 which is a fourth example of the present embodiment.

  The plurality of conductors 116 shown in FIG. 4 intersect each other, but there is no regularity in the manner of intersection. Except for the above, the description of the bonding material 101 illustrated in FIG. 3 is the same as the description of the bonding material 101 illustrated in FIG. 1. However, when the above description and the description of FIG.

  Note that the shape of each of the conductive wires 116 included in the bonding material 101 may not be similar to the shape illustrated in FIGS. 1 to 4. The length of each of the plurality of conducting wires 116 included in the conducting wire group including the conducting wires 116 only needs to be longer than the height of the bonding material 101.

  Note that the resin 111 shown in FIGS. 1 to 4 is not necessarily formed around the conductor group and between the conductors 116.

  For example, the resin 111 may not be formed around the conductor group. However, when the resin 111 is also formed on the periphery, each of the conductive wires 116 is more difficult to be removed.

  The resin 111 may not be formed near the center of the conductor group, for example. However, the effect of making each copper wire difficult to unwind is greater when the resin 111 is formed to the vicinity of the central portion.

  Furthermore, the resin 111 may be formed in, for example, a part of the periphery of the conductor group and a part between each of the conductors 116.

  FIG. 5 is a diagram illustrating a state in which an electronic component is bonded to a circuit board using the bonding material 101 illustrated in FIGS. 1 to 4.

  Solder 211 is attached in advance to each of the component electrodes 206 included in the electronic component 201.

  Also, solder 311 is attached in advance to each of the substrate electrodes 306 included in the circuit board 301.

  Further, the solder 151 is attached to the upper end of each of the bonding materials 101 and the solder 156 is attached to the lower end in advance.

  Then, each of the bonding materials 101 is placed on each of the solders 311.

  Then, the electronic component 201 is placed on each of the bonding materials 101 so that each of the solders 211 is placed thereon.

  Thereafter, the entire structure superposed as described above is heated at a temperature at which each of the solders 211, 151, 156 and 311 is melted.

  Thereby, each combination of the solder 211 and the solder 151 and each combination of the solder 156 and the solder 311 are integrated.

  As described above, each of the component electrodes 206 of the electronic component 201 is bonded to each of the corresponding substrate electrodes 306 via each of the bonding materials 101.

  FIG. 6 is a diagram illustrating a bonded body 501 that is a combination of the electronic component 201 and the circuit board 301 bonded according to the above description.

  Note that part or all of the resin 111 illustrated in FIG. 1 may be removed from the bonded body 501 illustrated in FIG. 6. The reason is that the resin 111 is not necessarily required after the conductive wire group 106 of the bonding material 101 is connected to the component electrode 206 and the substrate electrode 306 by solder. The reason for this is that the resin 111 is for facilitating the production of the joined body 501 using the joining material 101, and further for facilitating the production of the joining material 101 as will be described later. Because there is.

  The removal is performed, for example, by immersing the bonded body 501 in a solution in which the resin 111 is dissolved.

  FIG. 7 is an image diagram showing the bonded body 501 shown in FIG. 6 when the circuit board 301 is thermally expanded. Note that the bonding materials 1011 to 1015 illustrated in FIG. 7 are the bonding materials 101 illustrated in FIG. 6.

  The circuit board 301 shown in FIG. 7 is warped due to a difference in thermal expansion from the electronic component. At that time, the bonding materials 1011 and 1015 bonded to the component electrode 206 in the vicinity of the end of the electronic component 201 extend in the vertical direction.

  A main part that electrically connects the component electrode 206 and the substrate electrode 306 in the bonding materials 1011 and 1015 is a conducting wire 116 shown in FIGS. Then, as described above, the conductive wire 116 is formed so as to cross the stitch shape or is twisted together. Therefore, even if the joining material expands and contracts, the conducting wire group including the conducting wires 116 does not break immediately (see Patent Document 3). Therefore, even when the bonding materials 1011 and 1015 shown in FIG. 7 are extended to some extent, they can electrically connect the component electrode 206 and the substrate electrode 306.

  The degree to which the conductor group included in the bonding material can withstand expansion and contraction is the number of conductors constituting the conductor group, the thickness of each conductor, the type of thickness of each conductor (see FIG. 2), and how to entangle each conductor. It can be selected depending on the twisting method.

  Here, whether or not the resin 111 shown in FIGS. 1 to 4 is cracked in a state where the bonding material is extended like the bonding materials 1011 and 1015 depends on the electrical connection between the component electrode 206 and the substrate electrode 306. There is little influence. This is because, as described above, the main part that electrically connects the component electrode 206 and the substrate electrode 306 in the bonding materials 1011 and 1015 is the conductive wire 116 and not the resin 111.

  Whether or not the resin 111 is altered by heating or change with time has little influence on the electrical connection between the component electrode 206 and the substrate electrode 306. This is because, as described above, the main part that electrically connects the component electrode 206 and the substrate electrode 306 in the bonding materials 1011 and 1015 is the conductive wire 116 and not the resin 111. However, it is a premise that the conducting wire 116 is not deteriorated during the alteration.

  8 and 9 are image diagrams showing an example of a manufacturing method of the bonding material 101 shown in FIG.

  First, each of the conducting wires is knitted by a known method, and the conducting wire group base material 107 shown in FIG.

  Next, the lead wire group base material 107 is immersed in a solution 701 placed in a container 706 shown in FIG. The solution 701 is obtained by dissolving the resin 111 shown in FIGS. 1 to 4 in a solvent.

  In this state, the solution 701 may be pressurized. When the solution 701 is pressurized, the degree to which the solution 701 enters the gaps between the conductors in the conductor group base material 107 is improved.

  Next, the conductive wire group base material 107 is taken out of the solution 701. At this time, resin is present around and around the conductor group base material 107. When the solvent contained in the solution 701 is evaporated in this state, the joining base material 102 shown in FIG. 8C composed of the conductive wire group base material 107 and the resin 111 is formed.

  Next, when the joining base material 102 is cut into a predetermined length with, for example, a diamond cutter, the joining material 101 and the end material 191 are created as shown in FIG. The end material 191 may be discarded.

  The conducting wire group base material 107 is hardened by the resin 111 at the cutting stage. Therefore, each conducting wire included in the conducting wire group base material 107 is difficult to unwind during the cutting.

Therefore, the manufacturing method shown in FIGS. 8 and 9 is easier to cut compared to the case where the conductor group base material 107 is not hardened by the resin 111. Accordingly, the above manufacturing method can improve the yield at the time of manufacturing the bonding material.
[effect]
In the bonding material of this embodiment, the conducting wire group is hardened with resin. Therefore, compared with the case where the said joining material is not hardened with resin, each copper wire is hard to unwind and handling is easy. Accordingly, the bonding material can improve the yield when bonding electronic components or the like to a substrate or the like.

  Moreover, the manufacturing method of the bonding | jointing material of this embodiment forms resin after forming the conductor group of predetermined length in the solution etc. which melt | dissolved the said resin, and forms a joining base material. Then, the joined base material is cut into a predetermined length to form the joined body. The joining base material is obtained by solidifying the conductor group with the resin. Therefore, in the said joining base material, compared with the conductor group without the said resin, the probability that each conducting wire will be unwound in the case of the said cutting | disconnection is low. Therefore, the said manufacturing method can improve the yield at the time of manufacture of a conjugate | zygote.

  FIG. 10 is a block diagram illustrating a configuration of a bonding material 101x which is the minimum configuration of the bonding material according to the embodiment.

  The bonding material 101x includes a plurality of conductive wires and a resin (not shown).

  Each of the conducting wires is accommodated in a predetermined closed curved surface, the first end of the conducting wire is exposed from the first region of the closed curved surface, and the second end of the conducting wire is exposed from the second region of the closed curved surface. And the length of the said conducting wire is longer than the distance of said 1st area | region and said 2nd area | region.

  The resin is contained in the closed curved surface and is solid or close to solid.

  Since each of the conducting wires bends between the first region and the second region, the tolerance for expansion and contraction is large. That is, the bonding material 101x has a structure that can suppress breakage.

  Further, in the bonding material 101x, the conductor group is hardened by the resin inside the military curved surface. Therefore, the bonding material 101x has a low probability of unwinding the conducting wire when performing the bonding. Therefore, the bonding material 101x can improve the yield when bonding the two electrodes.

  That is, the bonding material 101x can suppress breakage of the bonded portion, and can improve the yield during bonding.

  Therefore, the bonding material 101x has the effects described in the section [Effects of the Invention] due to the above configuration.

  Note that the bonding material 101x is, for example, each of the bonding materials 101 illustrated in FIGS. 1 to 5 and 9 and each of the bonding materials 1011 to 1015 illustrated in FIG. Moreover, the said conducting wire is the conducting wire 116 represented, for example in FIG. 1 thru | or FIG. The resin is, for example, the resin 111 shown in FIGS. 1 to 4 and 8. The closed curved surface is, for example, a closed curved surface (not shown) that accommodates the conducting wire 116 shown in FIGS. 1 to 4.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and further modifications, substitutions, and adjustments may be made without departing from the basic technical idea of the present invention. Can be added. For example, the configuration of the elements shown in each drawing is an example for helping understanding of the present invention, and is not limited to the configuration shown in these drawings.

Further, a part or all of the above-described embodiment can be described as in the following supplementary notes, but is not limited thereto.
(Appendix 1)
It has a plurality of conductors and resin,
Each of the conducting wires is accommodated in a predetermined closed curved surface, the first end of the conducting wire is exposed from the first region of the closed curved surface, and the second end of the conducting wire is exposed from the second region of the closed curved surface. And the length of the conducting wire is longer than the distance between the first region and the second region,
The resin is contained in the closed curved surface and is solid or close to solid,
Bonding material.
(Appendix 2)
The bonding material according to attachment 1, wherein the resin is also formed around the closed curved surface.
(Appendix 3)
Appendix 1 or Appendix 2, which is at least one of a bundle of braids formed so that the plurality of conductors cross like a stitch, and a twisted wire obtained by twisting the plurality of conductors The described bonding material.
(Appendix 4)
The bonding material according to any one of supplementary notes 1 to 3, wherein the resin is a conductive resin.
(Appendix 5)
It is for joining a component electrode which is an electrode of an electronic component and a substrate electrode which is an electrode of a circuit board for installing the electronic component. Bonding material.
(Appendix 6)
The bonding material described in Appendix 5,
The component electrode joined to the first end of the joining material;
The substrate electrode bonded to the second end of the bonding material;
A junction structure comprising:
(Appendix 7)
A plurality of conducting wires and a resin, each of the conducting wires is accommodated in a predetermined closed curved surface, the first end of the conducting wire is exposed from the first region of the closed curved surface, and from the second region of the closed curved surface The second end of the conducting wire is exposed, and the length of the conducting wire is longer than the distance between the first region and the second region,
The resin is contained in the closed curved surface, and is a solid or near solid, a bonding material,
A component electrode of the electronic component first bonded to the first end of the bonding material;
An electrode of a circuit board for installing the electronic component, second bonded to the second end of the bonding material;
With
A joining structure in which the housing is performed on the closed curved surface during the first joining and the second joining.
(Appendix 8)
The joining structure according to appendix 7, wherein at least a part of the resin is removed after the first joining and the second joining.
(Appendix 9)
Forming a conductor group base material comprising at least one of a bundle of braids formed so that a plurality of conductor base materials cross in a knitted pattern, and a twisted wire obtained by twisting the conductor base materials;
Forming a joining base material in which a resin is formed between the conducting wire base materials in the conducting wire group base material;
Cutting the joining base material to a predetermined length;
Bonding material forming method.
(Appendix 10)
Forming the conductor group base material comprising a plurality of conductor base materials longer than the length of the conductor group base material;
Forming a joining base material in which a resin is formed between the conducting wire base materials in the conducting wire group base material;
Cutting the joining base material to a predetermined length;
A bonding material forming method, comprising: forming a bonding material including the conductive wire group including a plurality of conductive wires longer than the length of the conductive wire group.
(Appendix 11)
The bonding material forming method according to appendix 10, wherein the resin is also formed around the conductor group.
(Appendix 12)
By forming the wire group base material, immersing the wire group base material in a liquid for forming the resin, taking out the wire group base material from the liquid, and solidifying the resin The bonding material forming method described in Appendix 10 or Appendix 11.
(Appendix 13)
The bonding material forming method according to appendix 12, wherein the liquid is obtained by dissolving the resin in a solvent that dissolves the resin, and the solidification is performed by evaporating the solvent.
(Appendix 14)
The bonding material formation according to any one of appendix 10 to appendix 13, relating to a joined body for joining a component electrode which is an electrode of an electronic component and an electrode of a circuit board for installing the electronic component Method.
(Appendix 15)
A plurality of conducting wires and a resin, each of the conducting wires is accommodated in a predetermined closed curved surface, the first end of the conducting wire is exposed from the first region of the closed curved surface, and from the second region of the closed curved surface The second end of the conducting wire is exposed, and the length of the conducting wire is longer than the distance between the first region and the second region,
The resin is accommodated in the closed curved surface, and the first end of a bonding material that is solid or close to solid is first bonded to a component electrode that is an electrode of an electronic component,
The second end of the bonding material is second bonded to a substrate electrode that is an electrode of a circuit board for installing the electronic component,
Production method.
(Appendix 16)
The first joining is performed by first welding of a first solder attached to the first end and a second solder attached to the component electrode, and the second joining is performed to the second end. The manufacturing method according to appendix 15, which is performed by second welding of the third solder attached to the substrate and the fourth solder attached to the substrate electrode.
(Appendix 17)
The manufacturing method according to appendix 16, wherein the first welding and the second welding are performed simultaneously.
(Appendix 18)
The manufacturing according to appendix 16 or appendix 17, wherein the first welding and the second welding are performed by simultaneously heating the first solder, the second solder, the third solder, and the fourth solder. Method.
(Appendix 19)
The manufacturing method according to any one of Appendix 15 to Appendix 18, wherein at least a part of the resin is removed after the first bonding and the second bonding.

101, 1011, 1012, 1013, 1014, 1015, 101x Bonding material 102 Bonding base material 106 Conductive wire group 107 Conductive wire group base material 111 Resin 116 Lead wire 151, 156, 211, 311 Solder 191 End material 201 Electronic component 206 Component electrode 301 Circuit Substrate 306 Substrate electrode 701 Solution 706 Container

Claims (10)

It has a plurality of conductors and resin,
Each of the conducting wires is accommodated in a predetermined closed curved surface, the first end of the conducting wire is exposed from the first region of the closed curved surface, and the second end of the conducting wire is exposed from the second region of the closed curved surface. And the length of the conducting wire is longer than the distance between the first region and the second region,
The resin is contained in the closed curved surface and is solid or close to solid,
Bonding material.   The bonding material according to claim 1, wherein the resin is also formed around the closed curved surface.   The braided bundle wire formed so that the plurality of the conducting wires intersect in a stitch shape and at least one of the twisted wires obtained by twisting the plurality of the conducting wires together. 2. The bonding material described in 2.   4. The device according to claim 1, which is for joining a component electrode that is an electrode of an electronic component and a substrate electrode that is an electrode of a circuit board for installing the electronic component. 5. Bonded material. A bonding material according to claim 4;
The component electrode joined to the first end of the joining material;
The substrate electrode bonded to the second end of the bonding material;
A junction structure comprising: Forming a conductor group base material comprising at least one of a bundle of braids formed so that a plurality of conductor base materials cross in a knitted pattern, and a twisted wire obtained by twisting the conductor base materials;
Forming a joining base material in which a resin is formed between the conducting wire base materials in the conducting wire group base material;
Cutting the joining base material to a predetermined length;
Bonding material forming method. Forming the conductor group base material comprising a plurality of conductor base materials longer than the length of the conductor group base material;
Forming a joining base material in which a resin is formed between the conducting wire base materials in the conducting wire group base material;
Cutting the joining base material to a predetermined length;
A bonding material forming method, comprising: forming a bonding material including the conductive wire group including a plurality of conductive wires longer than the length of the conductive wire group.   By forming the wire group base material, immersing the wire group base material in a liquid for forming the resin, taking out the wire group base material from the liquid, and solidifying the resin The bonding material forming method according to claim 6, wherein the bonding material is formed. A plurality of conducting wires and a resin, each of the conducting wires is accommodated in a predetermined closed curved surface, the first end of the conducting wire is exposed from the first region of the closed curved surface, and from the second region of the closed curved surface The second end of the conducting wire is exposed, and the length of the conducting wire is longer than the distance between the first region and the second region,
The resin is accommodated in the closed curved surface, and the first end of a bonding material, which is solid or close to solid, is first bonded to a component electrode which is an electrode of an electronic component,
The second end of the bonding material is second bonded to a substrate electrode that is an electrode of a circuit board for installing the electronic component,
Production method.   The manufacturing method according to claim 9, wherein at least a part of the resin is removed after the first bonding and the second bonding.

Images