JP2011003780A - Conductive junction structure and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive junction structure to form a stable connection state by electrically bonding a land-shaped connection terminal and a spring contactor.SOLUTION: The structure has the land-shaped connection terminal 3a, and the spring contactor 2 electrically contacting with the land-shaped connection terminal 3a, by applying an energizing force to the land-shaped connection terminal 3a. The land-shaped connection terminal 3a is provided with Sn-Ag plating 3ac on contact surfaces with the spring contactors 2, such as a spiral contactor 2, a leaf spring contactor, and a coil spring shaped contactor. At least one pair of the land-shaped connection terminal 3a and the spring contactor 2 is formed. An inter-metal joining part 9 is formed on the contact surface, by making the land-shaped connection terminal 3a and the spring contactor 2 face each other to be superposed. The inter-metal joining part 9 is formed between the Sn-Ag plating 3ac and Au plating 7b, and stably jointed, without adding a heat history to an electronic component 3, etc.

Description

  The present invention relates to a conductive joint structure that forms an electrical connection state, and relates to a conductive joint structure that includes an intermetallic joint on a contact surface that electrically joins a land-like connection terminal and a spring-like contact.

FIG. 6 is a cross-sectional view schematically showing the intermetallic bonding between the spiral contact and the connection terminal, where (a) shows a state before contact, and (b) shows metal indirect at the contact location after contact. The state where the merger is generated is shown.
As shown in FIGS. 6A and 6B, the land-like connection terminals 103a and the land-like connection terminals 103a are biased to come into electrical contact with the land-like connection terminals 103a so that the predetermined conductivity of the substrate 103b is obtained. In the spiral contact 102 joined so as to be electrically connected to the part, the land-like connection terminal 103a and the spiral contact 102 have a mirror-like plane 103ac and a mirror-like plane whose contact surfaces are mirror-finished. 102c, and the mirror-like planes of the land-like connection terminal 103a and the spiral contactor 102 face each other and overlap each other. The spring-like nature of the spiral contactor 102 brings the mirror-like planes into close contact with each other and further pressurizes. As a result, an intermetallic joint 109 is generated and can be electrically and firmly joined (see Patent Document 1).

Japanese Patent Application No. 2008-268268

However, in the conventional example, a connection terminal having a mirror-like plane on the connection surface and a spiral contact having a mirror-like plane on the top surface of the tip are joined, and the mirror-like plane is on the top of the tip. The spiral contactors provided with are joined together.
The present invention is to stably form an electrical connection state by generating an intermetallic joint without forming a contact surface obtained by electrically joining a land-like connection terminal and a spring-like contactor as a mirror-like plane. Objective.

The conductive joint structure of the invention according to claim 1 includes a land-like connection terminal, and a spring-like contactor that applies a biasing force to the land-like connection terminal and makes electrical contact with the land-like connection terminal,
The land-shaped connection terminal is Sn-Ag plated on the contact surface with the spring-shaped contact,
By providing at least one pair of the land-like connection terminal and the spring-like contact, and facing and overlapping the land-like connection terminal and the spring-like contact, an intermetallic joint is generated on the contact surface. It is characterized by that.

  The invention according to claim 2 is the conductive joint structure according to claim 1, wherein the spring-like contactor is a spiral contactor.

  The invention according to claim 3 is the conductive joint structure according to claim 1, wherein the spring-like contactor has a leaf spring shape.

  The invention according to claim 4 is the conductive joint structure according to claim 1, wherein the spring-like contactor has a coil spring shape.

  According to a fifth aspect of the present invention, there is provided a method for manufacturing a conductive joint structure, wherein at least a pair of the land-like connection terminals and the spring-like contactors are provided, and the land-like connection terminals and the spring-like contactors face each other and overlap each other. A method of manufacturing a conductive joint structure in which an intermetallic joint is generated on the contact surface by combining, and applying low frequency vibration to at least one of the land-like connection terminal and the spring-like contactor An inter-joint is generated.

  According to a sixth aspect of the present invention, there is provided a method for manufacturing a conductive joint structure, wherein at least a pair of the land-like connection terminals and the spring-like contactors are provided, and the land-like connection terminals and the spring-like contactors face each other and overlap each other. A method of manufacturing a conductive joint structure in which an intermetallic joint is generated on the contact surface by combining the metal, and the joint between the land-like connection terminal and the spring-like contact is made an inert gas atmosphere. An inter-joint is generated.

  According to a seventh aspect of the present invention, there is provided a method for producing a conductive joint structure, wherein at least a pair of the land-like connection terminals and the spring-like contactors are provided, and the land-like connection terminals and the spring-like contactors face each other and overlap each other. A method for manufacturing a conductive joint structure in which an intermetallic joint is generated on the contact surface by combining the joints between the land-like connection terminal and the spring-like contact in a normal temperature atmosphere and a low-temperature heating atmosphere. One of them is characterized in that an intermetallic joint is generated.

  The invention according to claim 8 is the method for manufacturing the conductive joint structure according to claim 7, wherein the low-temperature heating atmosphere is a spot-like infrared lamp.

  The invention according to claim 9 is the method for manufacturing a conductive joint structure according to claim 7, wherein the low-temperature heating atmosphere is a heated inert gas.

  The invention according to claim 10 is the method of manufacturing a conductive joint structure according to claim 7, wherein the low temperature heating atmosphere is based on heating using a heater.

  The invention according to an eleventh aspect is the method for producing a conductive joint structure according to the seventh aspect, wherein the low-temperature heating atmosphere is 80 to 120 ° C.

  According to claim 1, the conductive joint structure includes a land-like connection terminal, and a spring-like contact that applies an urging force to the land-like connection terminal to make electrical contact with the land-like connection terminal. The terminal is Sn-Ag plated on the contact surface with the spring-like contactor, and at least a pair of land-like connection terminals and spring-like contactors are provided, and the land-like connection terminals and the spring-like contactors face each other and overlap each other. By combining them, it is possible to generate an intermetallic joint between the Sn—Ag plating and the Au plating and stably join without adding a thermal history to the electronic component or the like.

  According to the second aspect, since the spring-like contact is a spiral contact, the land-like connection terminal and the spiral contact are faced and overlapped to generate an intermetallic joint on the contact surface. Can be joined together.

  According to the third aspect of the present invention, since the spring-like contact has a leaf spring shape, an intermetallic joint is generated on the contact surface by causing the land-like connection terminal and the leaf spring-like contact to face each other and overlap each other. And can be stably joined.

  According to the fourth aspect of the present invention, since the spring-like contact has a coil spring shape, the land-like connection terminal and the coil spring-shaped contact are faced and overlapped to generate an intermetallic joint on the contact surface. Can be joined together.

  According to claim 5, at least a pair of land-like connection terminals and spring-like contacts are provided, and the land-like connection terminals and the spring-like contactors face each other to overlap each other, so that at least one of the land-like connection terminals and the spring-like contactors is provided. On the other hand, it is possible to generate an intermetallic joint between the connection terminal and the contact without applying thermal history to the electronic component by applying low frequency vibration.

  According to the sixth aspect, at least a pair of land-like connection terminals and spring-like contacts are provided, the land-like connection terminals and the spring-like contactors face each other, and the land-like connection terminals and the spring-like contactors are overlapped. It is possible to generate an intermetallic joint between the connection terminal and the contact without placing the joint in an inert gas atmosphere and applying a thermal history to the electronic component or the like.

  According to the seventh aspect, at least a pair of land-like connection terminals and spring-like contacts are provided, the land-like connection terminals and the spring-like contactors face each other, and the land-like connection terminals and the spring-like contactors are overlapped. It is possible to generate an intermetallic joint between the connection terminal and the contact without adding a thermal history to the electronic component or the like by setting the joint to one of a normal temperature atmosphere and a low temperature heating atmosphere.

  According to the eighth aspect of the present invention, the low temperature heating atmosphere can effectively heat the space between the connection terminal and the contact by using a spot-like infrared lamp to generate an intermetallic joint.

  According to the ninth aspect of the present invention, the low temperature heating atmosphere uses the heated inert gas to effectively heat the connection terminal and the contact without being oxidized, thereby generating an intermetallic joint. Can do.

  According to the tenth aspect, the low-temperature heating atmosphere can be heated using a heater to effectively heat the connection terminal and the contact, thereby generating an intermetallic joint.

According to the eleventh aspect, by setting the low temperature heating atmosphere to 80 to 120 ° C., it is possible to generate an intermetallic joint between the connection terminal and the contact without adding a thermal history to the electronic component or the like. it can.
Thereby, it is possible to easily form a conductive joint structure including a spring-like contactor with high accuracy, excellent electrical characteristics, and excellent spring followability.

<First Embodiment>
Hereinafter, a first embodiment of a conductive bonding structure according to the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a conductive joint structure for explaining a first embodiment of the present invention, (a) shows a state before contact between a spiral contact and a land-like connection terminal, and (b) shows The state where the joint part between metals is produced | generated in the contact location after contact is shown.
As shown in FIGS. 1 (a) and 1 (b), the conductive bonding structure 1 includes a land-like connection terminal 3a and a spring that applies an urging force to the land-like connection terminal 3a and makes electrical contact with the land-like connection terminal 3a. The land-like connection terminal 3a is provided with a Sn-Ag plating 3ac on the contact surface with the spring-like contact 2, and the land-like connection terminal 3a and the spring-like contact are provided. 2 and at least a pair of land-like connection terminals 3a and spring-like contactors 2 facing each other, and low frequency vibration, for example, 50 Hz vibration, is applied to either the electronic component 3 or the spiral contactor 2. Is easily generated on the contact surface. The low-frequency vibration is generated by a piezo element. However, the low-frequency vibration may be generated by a motor used to vibrate a mobile phone as long as it generates low-frequency vibration. It is also possible to fix the electronic component 3 or printed circuit board provided with a spring-like contact (spiral contact 2) on a large table and vibrate at a low frequency of about 30 Hz to generate a metal-to-metal joint. . In addition, Sn-Ag plating is applied to the surface of the connection terminal or contactor to generate the metal-to-metal joint. However, when the surface of the connection terminal or contactor is covered with Sn-Ag, it is not limited to plating. Alternatively, sputtering or coating may be used.

FIG. 2 is an enlarged cross-sectional view for explaining the intermetallic joint, and shows an atmosphere in which the intermetallic joint is generated. As shown in FIG. 2, in order to form the conductive joint structure 1, the joint part (intermetallic joint part 9) of the electronic component 3 and the spring-like contactor (spiral contactor) 2 is placed in the chamber 11. Then, an inert gas, for example, nitrogen gas is filled to prevent oxidation. Moreover, it is possible to produce | generate an intermetallic junction more effectively by heating a junction part (site | part which produces | generates the intermetallic junction part 9) at low temperature. Low temperature heating is performed by filling the chamber with a heated inert gas, heating with an infrared lamp, or heating with a heater such as a nichrome wire.
As described above, the conductive bonding structure 1 has a metal between the Sn-Ag plating 3ac of the land-like connection terminal 3a and the Au plating 3 of the spiral contact 2 without applying a thermal history to the electronic component 3 or the like. It is possible to generate the inter-joint portion 9 and stably join. In addition, although the low temperature heating atmosphere was 80-120 degreeC, if it is a range without the influence of the heat history to an electronic component or a device, it will not be limited to this.

Next, a method for manufacturing a spiral contact which is a spring-like contact will be briefly described.
FIG. 3 is a process cross-sectional view of the method for manufacturing a spiral contact according to the present invention. As shown in FIG. 3, the spiral contact 2 is a convex spiral contact having a tip (column) 2d at the center of the spiral. Note that the shape of the spiral contact 2 is not limited to the one provided with the pillar 2d as long as the portion in contact with the connection terminal has a flat tip.

In the first step, the metal plate 4 is prepared, and one concave portion 4a is formed on the surface of the metal plate 4 so as to come to the position of the tip of the spiral contact. Since the metal plate 4 is preferably a Cu foil, the metal plate 4 is hereinafter referred to as a Cu foil 4. The thickness of the Cu foil 4 is a foil shape, for example, 0.08 mm, but is not limited thereto.
In the second step, a photoresist 5 is affixed or applied to the surface of the Cu foil 4, and a photomask 6 having a pattern of the triple spiral contact 2 is covered from above, and light is applied from above the photomask 6. To expose. Thereby, the pillar 2d is formed. The shape of the photomask 6 is a pattern in which the spiral contact 2 is blackened. Further, a method using a reverse black and white pattern may be used.

In the third step, the photoresist 5 is developed so as to form a pattern of the photomask 6.
In the fourth step, the metal material 7 (7a, 7b) is further applied to the exposed surface 4b of the Cu foil 4 from above, and the triple wound spiral contact 2 is formed. The metal material 7 here is preferably a nickel alloy with a Cu material applied to the surface layer or a nickel alloy plating with a Cu material applied to the surface layer. In addition, although nickel nickel alloy plating was used for the metal material, for example, it is not limited to this.
In the fifth step, the photoresist 5 is removed.
In the sixth step, a photoresist 5 is pasted or applied on the back surface of the Cu foil 4, and a photomask 6 'for making a hole is covered, and this photomask 6' is irradiated with light to be exposed and developed.
In the seventh step, a hole 4c is formed in the Cu foil 4 from the back surface of the Cu foil 4 by etching.
In the eighth step, the photoresist 5 on the back surface of the Cu foil 4 is removed.

FIG. 4 is a process sectional view of the manufacturing method according to the present invention, and shows a process following the eighth process shown in FIG. As shown in FIG. 4, in the ninth step, annealing forming is performed in a state where the center of the spiral of the spiral contact 2 turned upside down is pushed up from one side by the convex tool 10 and deformed into a convex shape.
Specifically, the convex tool 10 is arranged below the spiral contact 2, and the forming is stabilized by annealing and forming the spiral contact 2 with the convex tool 10 pushed up from below and deformed into a convex shape. That is, the spiral contact 2 deformed into a convex shape is heated and annealed to be formed into a convex shape. In this annealing forming, for example, heating is performed at 250 ° C., annealing is performed, and internal stress is removed. Although the heating temperature is 250 ° C. here, it is assumed to include around 250 ° C., and is not limited to this.
The tenth step is a state in which the annealing tooling is completed and the convex tool 10 is removed.
In the eleventh step, the spiral contact 2 is positioned and fixed on the mounting substrate 8 having the conductive land 8a on the surface. Thereafter, the Cu foil 4 is removed by etching.

<Other embodiments>
Hereinafter, other embodiments of the conductive joint structure according to the present invention will be described in detail with reference to the drawings. The method for generating the intermetallic joint is the same as in the first embodiment, and the description of the generation method is omitted, and a different specific structure will be described.
FIG. 5 shows a conductive joint structure for explaining another embodiment of the present invention, in which (a) shows a leaf spring shape, and (b) shows a coil spring shape contact.
As shown in FIG. 5A, in the conductive joint structure 11, the spring-like contact 12 has a leaf spring shape. Thus, the land-like connection terminal 31a and the leaf spring-shaped spring-like contactor 12 face each other and overlap each other, whereby the intermetallic joint 19 can be generated on the contact surface and stably joined. The spring-like contact 12 is joined by providing a soldering portion 14 or the like on the land-like connection terminal 33a. Sn-Ag plating 31ac is applied to the joint surface of the leaf-like spring-like contactor 12 that contacts the land-like connection terminal 31a.

Moreover, as shown in FIG.5 (b), in the electroconductive joining structure 21, the spring-like contactor 22 is a coil spring shape. As described above, the land-like connection terminal 41a and the coil spring-shaped spring-like contactor 22 face each other and overlap each other, whereby the intermetallic joint 29 can be generated on the contact surface and stably joined. The spring-like contact 22 is joined by providing a soldering portion 24 or the like on the land-like connection terminal 51a. Sn-Ag plating 41aa is applied to the joint surface of the coil spring-like spring contact 22 that contacts the land connection terminal 41a.
Note that the solder joints (soldering portions) 14 and 24 may be laser spot welding or the like, as long as electrical joining is possible, or any other joining method or metal joining used in the present invention.

The core material forming the spring-like contacts 2, 12, and 22 is a nickel (Ni) base material, and the surface thereof is plated with Au. However, the present invention is not limited to this. Here, the metal-to-metal bonding will be briefly described. The metal-to-metal bonding occurs when metal atoms in the bonding part diffuse to each other to generate diffusion bonding. Diffusion bonding is defined by JIS as follows: “Diffusion of atoms generated between bonding surfaces is made by pressing the base material in close contact and pressurizing the base material to the extent that plastic deformation does not occur as much as possible. To join ".
The feature of such diffusion bonding is that it is possible to bond metals and dissimilar metals that are extremely difficult to melt and weld to each other, and to perform surface bonding.

That is, the bonding surfaces of the metals to be bonded are pressed and heated without significant deformation, and the atoms at the bonding interface are diffused across the bonding surface and bonded. At this time, since surface irregularities, oxide films, and contaminated layers are factors that hinder bonding, strict control of the amount of plastic deformation by pressurization, diffusion rate by heating, and surface treatment is required. Precise bonding is possible by suppressing interdiffusion between bonding materials by condition control.
Further, metal bonding is more likely to occur at a low temperature of 100 ° C. or lower, in a vacuum, or in an inert gas.

  The preferred embodiments have been described above. However, the present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the gist of the present invention. For example, the spring-like contactor has been described as having a protrusion (column) at the center tip of the spiral contactor. In addition, the spring-like contactor has been described as a plate spring shape and a coil spring shape, but the present invention is not limited to this, and any other spring-like contactor may be used, and a contact provided with an intermetallic joint on a thin metal plate. You may comprise.

It is sectional drawing which shows the electroconductive joining structure for demonstrating the 1st Embodiment of this invention, (a) shows the state before contact of a spiral contact and a land-shaped connection terminal, (b) The state in which the intermetallic joint part is produced | generated in the contact location after the contact is shown. It is an expanded sectional view explaining metal-to-metal joining, and has shown the atmosphere where a metal-to-metal junction part is produced | generated. It is process sectional drawing for demonstrating the manufacturing process of the spiral contactor which concerns on the 1st Embodiment of this invention. It is process sectional drawing for demonstrating the manufacturing process of the spiral contactor which concerns on the 1st Embodiment of this invention. The conductive joining structure for describing other embodiment of the present invention is shown, (a) shows a leaf spring shape and (b) shows a coil spring shape contact. It is sectional drawing which shows the outline of the conventional metal joint of a spiral contactor and a connection terminal, (a) shows the state before a contact, (b) shows the metal joint part in a contact location after a contact. Indicates the state being generated.

This is a conductive joint structure in which an intermetallic joint is generated and a stable electrical connection state is formed without forming a contact surface obtained by electrically joining the land-like connection terminal and the spring-like contactor as a mirror-like plane. Thus, the present invention is applied to an interconnect for forming a highly integrated device by connecting electronic boards such as between electronic components and between mounting boards.

1, 11, 21 Conductive bonding structure 2, 12, 22 Spiral contact, spring contact 2d Tip 3 Electronic component 3a Land connection terminal 3aa Cu
3ab Au plating 3ac Sn-Ag plating 3d land 4 Cu
4a Concave, hollow 4b Cu exposed surface (upper surface)
4c Hole 5 Photoresist 6, 6 'Photomask 7 Metal plating, metal material 7a Ni plating, metal material 7b Au plating, metal material 8 Mounting substrate 9, 19, 29 Intermetallic joint 10 Convex tool 11 Chamber

Claims (11)

A land-like connection terminal, and a spring-like contactor that applies an urging force to the land-like connection terminal to make electrical contact with the land-like connection terminal,
The land-shaped connection terminal is Sn-Ag plated on the contact surface with the spring-shaped contact,
By providing at least one pair of the land-like connection terminal and the spring-like contact, and facing and overlapping the land-like connection terminal and the spring-like contact, an intermetallic joint is generated on the contact surface. A conductive joint structure characterized by the above.   The conductive joint structure according to claim 1, wherein the spring-like contact is a spiral contact.   The conductive joint structure according to claim 1, wherein the spring-like contact has a leaf spring shape.   The conductive joint structure according to claim 1, wherein the spring-like contact has a coil spring shape.   By providing at least one pair of the land-like connection terminal and the spring-like contact, and facing and overlapping the land-like connection terminal and the spring-like contact, an intermetallic joint is generated on the contact surface. A method for producing a conductive joint structure, comprising: forming a metal-to-metal joint by applying low-frequency vibration to at least one of the land-like connection terminal and the spring-like contactor. Production method.   By providing at least one pair of the land-like connection terminal and the spring-like contact, and facing and overlapping the land-like connection terminal and the spring-like contact, an intermetallic joint is generated on the contact surface. A method for manufacturing a conductive joint structure, wherein a joint part between the land-like connection terminal and the spring-like contactor is formed in an inert gas atmosphere to generate an intermetallic joint part. Production method.   By providing at least one pair of the land-like connection terminal and the spring-like contact, and facing and overlapping the land-like connection terminal and the spring-like contact, an intermetallic joint is generated on the contact surface. A method for producing a conductive bonding structure, characterized in that an intermetallic bonding portion is generated by setting a bonding portion between the land-like connecting terminal and the spring-like contactor to one of a normal temperature atmosphere and a low temperature heating atmosphere. A method for manufacturing a conductive bonding structure.   The method of manufacturing a conductive joint structure according to claim 7, wherein the low-temperature heating atmosphere is a spot-like infrared lamp.   The method for manufacturing a conductive joint structure according to claim 7, wherein the low-temperature heating atmosphere is a heated inert gas.   The method for manufacturing a conductive bonding structure according to claim 7, wherein the low-temperature heating atmosphere is based on heating using a heater. The method for manufacturing a conductive bonding structure according to claim 7, wherein the low-temperature heating atmosphere is 80 to 120 ° C.