JP2006315027A - Member-fixing method, portion and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for easily joining a wire-shaped member which is difficult to solder and braze. <P>SOLUTION: In this fixing method of the member, the wire-shaped member 103 is locked by forming a built-up metal part 102 made of a low melting point alloy which has high wettability to a member to be locked on the member to be locked such as an electronic substrate, sinking the wire-shaped member 103 of the object of locking into a molten built-up metal part 102 and imparting plastic deformation to the built-up metal part by a deforming means 104 such as a pressure member after the built-up metal part 102 is cooled and solidified. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

Wires and micro coils made of materials that are difficult to braze or solder
The present invention relates to a method and an apparatus for fixing to an electronic substrate, a metal plate, a metal wire or the like.

Generally, when attaching a linear member to an electronic substrate or the like, soldering or brazing is used. Since linear members made of materials that have poor affinity with solder alloys and brazing metals cannot be soldered or brazed as they are, solder alloys and brazing metals using ultrasonic waves etc. Means, such as improving affinity with, are known.

Therefore, for joining linear members that cannot be soldered conventionally, a method of attaching to a substrate or the like by separately providing a crimping terminal or a sleeve has been taken. We proposed a fixing method that can easily and firmly attach non-solderable alloy wires to electronic boards. (See Patent Document 1)

JP2004-7682

However, even if the attachment is improved with ultrasonic waves or the like, the bonding force is weak, and when an external force is applied, the attachment portion gradually loosens and may fall off.
In the method of attaching and attaching the crimping terminal and sleeve separately, it is necessary to separately solder and screw to fix the terminal, and it is necessary to secure the space of the terminal and sleeve, so the fixing part is enlarged and the process There was a risk of complications.
In addition, spot welding may be used as another means, but a large heating load is applied to the linear member to be fixed. The characteristics are determined by the properties of the alloy between the linear member and the member to be fixed, and it is impossible to fix the linear member that cannot form an alloy or when the alloy is highly brittle, or when a large external force is applied. There was a problem that the alloy layer could not withstand.

In view of the above problems, the present invention is a wire made of a material that is difficult to solder, braze, or weld, such as aluminum, titanium alloy, tungsten alloy, nickel titanium shape memory alloy, carbon fiber, glass, ceramic, or polymer. The present invention relates to a method for fixing a shape member to an electronic substrate, a metal plate, a metal wire or the like in a limited space with a strong and simple process.

One embodiment of the present invention is a method for fixing a shape memory alloy in an actuator mechanism that drives a nickel-titanium shape memory alloy by energization heating.
A deposit part is formed of a low melting point metal on an electronic substrate to be a fixed member, and a shape memory alloy wire as a linear member is installed in the deposit part.
Further, after cooling and solidifying the depositing portion, it is fixed by applying plastic deformation with a pressing member such as a punch.
The low melting point metal is a metal material having a melting point sufficiently lower than that of the linear member and the portion for fixing the metal or the like forming the pattern surface on the electronic substrate, and having high wettability with the metal to be fixed. It is possible to form a depositing portion that becomes a fixing portion without damaging the fixing target portion, and the processing is also easy. For electronic substrates, solder alloys are easy to use

.
Nickel-titanium-based shape memory alloy has poor affinity with a solder alloy and cannot be firmly fixed by soldering alone. It is firmly fixed by sliding frictional resistance with the shape memory alloy wire.
In addition, even if the shape memory alloy wire has an oxide film, dirt, etc., and the electrical contact is obstructed as it is, the oxide film or dirt on the surface of the wire is destroyed when plastic deformation is applied. Connections can be made.

One form of the present invention. This is a fixing device for joining a linear member to an electronic substrate.
From a mechanism for placing a low melting point metal, a mechanism for melting a low melting point metal to form a banking part, a mechanism for placing a linear member in the banking part, and a pressing mechanism that presses the banking part and gives plastic deformation Composed.
A low melting point metal is disposed on the fixing target portion of the electronic substrate, and the low melting point metal is melted by a melting means to form a depositing portion bonded to the substrate. Furthermore, a linear member is arranged inside the molten low melting point metal, and after heat removal, plastic deformation is applied by pressing means to achieve fixation.
The linear member fixing device according to the present invention has a simple configuration and can be fixed well.

According to the present invention, it is possible to easily join linear members that are difficult to solder or braze.

Hereinafter, a linear member fixing method and apparatus according to the present invention will be described with reference to the drawings.

This example is an example in the case of joining an alloy wire to a metal plate using the present invention.
FIG. 1 is a view showing a state before joining alloy wires.
Reference numeral 101 denotes a metal plate, and reference numeral 102 denotes a depositing portion made of a low melting point metal.
The banking part 102 is installed on the metal plate 101 by melting a low melting point metal.
At this time, an alloy of the low melting point metal and the metal plate is formed and fixed at the joint between the low melting point metal and the metal plate.
In addition, if the metal has a low melting point and has a high surface tension, it is possible to easily form the raised portion 102.
FIG. 2 is a view showing a state when the alloy wires are joined.
Reference numeral 103 denotes an alloy wire.
The depositing part 102 is melted by heating, and the alloy wire 103 is submerged and installed.
FIG. 3 shows the alloy wire 103 submerged. It is a figure which shows the state which cooled and solidified the deposit part 102. FIG.
FIG. 3A is a schematic view, and FIG. 3B is a cross-sectional view of the fixing portion.
In this state, the alloy wire 103 is in a temporarily fixed state that can be taken out when pulled strongly from the outside.
FIG. 4 is a view showing a state in which the metal bank 102 is plastically deformed by the pressing means.
In this embodiment, the pressing means performs plastic deformation using the punch 104.
By pressing the metal depositing part 102 with the punch 104 and plastically deforming, the sliding frictional resistance between the alloy wire 103 and the metal depositing part 102 is increased and is firmly fixed.
The fixing portion according to the present invention has a fixing force determined by the state of the sliding frictional resistance.
By changing the shape of the pressing member that gives plastic deformation, the sliding frictional resistance can be adjusted, and the fixing force and properties can be determined.
FIG. 5 shows a fixed state in which the plastic deformation due to the pressing member of the raised portion 102 formed of a low melting point metal on the fixed portion 100 is formed to resist the planned movement direction.
A contact portion of the pressing member 104 ′ with the raised portion is formed in a sawtooth shape, and plastic deformation is given by the pressing member 104 ′.
If plastic deformation is performed by this pressing member, the pressure distribution is changed, the sliding frictional resistance in the planned motion direction is increased, and a stronger fixing portion can be obtained.
In addition, if the saw blade is formed to be inclined with respect to the planned movement direction as shown in FIG. 6, the frictional load can be dispersed, and there is a risk that the linear member breaks or the fixed part breaks due to the concentrated load. Can be reduced.

In this embodiment, the shape memory alloy is fixed to the electronic substrate.
Titanium-nickel shape memory alloys have poor affinity with solder alloys and brazing metals, and it has been difficult to directly fix them on the surface of a conductor pattern of an electronic board by ordinary soldering or brazing. Especially in the case of titanium-nickel shape memory alloy wires that need to maintain electrical connection in a state where a mechanical load is applied when driving by energization heating, improve wettability with ultrasonic waves, etc. Even if brazing or brazing, the fixed part gradually loosens when it is repeatedly exercised, and in the worst case it slips through and becomes unusable.
Further, if an oxide film or dirt adheres to the shape memory alloy wire, it becomes an energizing resistance, which hinders good driving.

FIG. 7 is a diagram showing a fixed state in the present embodiment.
Reference numeral 201 denotes an electronic substrate, 202 denotes a conductive pattern portion, 203 denotes a deposit portion made of a low melting point metal, and 204 denotes a shape memory alloy wire.
The conductive pattern 202 is made of copper, lead-free solder is used as the low melting point metal of the metal depositing portion 203, and the shape memory alloy wire 204 is made of nickel-titanium.
The lead metal 203 and lead pattern 202 made of lead-free solder have high copper wettability and are firmly bonded. After embedding the shape memory alloy wire 204, plastic deformation was applied by the pressing member 205.
Unlike soldering, the shape memory alloy wire 204 is not directly heated and joined, so that the composition of the shape memory alloy is not destroyed, and a large friction is generated between the plastically deformed plated portion 203 and the shape memory alloy wire 204. It creates resistance.
Further, when plastic deformation is applied, dirt and oxide film on the surface of the shape memory alloy wire 204 are destroyed, so that an unexpected electrical resistance that may occur between the shape memory alloy wire 204 and the plating portion 203 is removed. The

As described above, according to the present invention, both a strong mechanical connection and a good electrical connection can be obtained by a simple process.

The low melting point metal in the present invention preferably has the following conditions.
(1) High wettability between mounted member and low melting point metal (2) High surface tension.
(3) High tensile strength (4) High hardness (5) Work hardening is likely to occur

In the joining method according to the present invention, a metal deposit portion that is firmly joined to the attached member is formed using a low melting point metal having high wettability with the attached member. In addition, if the surface tension is high, it is easy to form the raised portion. If the tensile strength is high and the hardness is high, a fixed portion that is strong against external force and deformation of the linear member can be obtained.
Such low melting point metals are generally solder alloys. However, high hardness, high tensile strength, and the like are characteristics of solder alloys that are avoided, such as causing formation of solder bridges, and are characteristics that appear in lead-free solder, eutectic solder, and the like.
Moreover, if plastic deformation to the metal bank is performed by cold working, work hardening occurs and the strength of the metal bank increases.
In particular, when a large external force is applied to the linear member or when the shape memory alloy is fixed, the depositing part cannot withstand the external force or the deformation of the shape memory alloy, and may fall off from the depositing part. However, various properties are improved by causing work hardening by cold working, and a tougher fixing portion can be obtained.

Hereinafter, the result of the verification test of the effect of the fixing method according to the present invention will be shown.
The tensile strength was measured when a titanium-nickel shape memory alloy wire having a diameter of 75 μm and a wire strength of 425 gf was joined to a square copper foil pattern of 2 mm square on an electronic substrate.
The low melting point metal used is a commonly used solder of tin 60% -lead 40% and lead-free solder (Sn-3% Ag-0.5Cu-0.1% Bi).
The contact shape of the pressing means was a flat surface and a sawtooth shape, and was applied with a load of 60 kg.
Table 1 below shows the results of this comparative test.

Compared to the state without plastic deformation, the tensile strength is significantly increased.
The fixed part by lead-free solder which gave plastic deformation was almost the same as the wire strength.
Furthermore, when a wire rod diameter of 50 μm was used, and a repeated operation test of 40 gf was performed on a lead-free solder and a fixed portion obtained by a sawtooth-shaped plastic deformation, it was able to withstand repeated tensile operations of 12 million times or more. .
Thus, the fixing method according to the present invention can increase the strength significantly by a simple method.

This embodiment is an embodiment in the case of joining a linear member to a metal plate as in the first embodiment.
A linear member is disposed on the member to be fixed, and a low melting point metal is melted thereon to form a banking portion.
Furthermore, it fixes by giving a plastic deformation to a metal-welding part using a press means.
The difference from the first embodiment is the order of the steps. Although it is affected by heat as compared with Example 1, the same fixed part can be obtained.

The present embodiment is an embodiment in the case of joining a material having a low softening point such as a fishing line or a material easily combustible such as a cotton thread.
FIG. 8 is a diagram showing a first step of the present embodiment.
Reference numeral 301 denotes a member to be fixed, 302 a depositing portion made of a low melting point metal, and 303 a linear member made of a material having no affinity with the low melting point metal.
Similar to the first embodiment, the low melting point metal is melted to form the banking portion 302, and the linear member 303 is submerged.
FIG. 9 is a diagram showing a second step of the present embodiment.
After cooling and solidifying the depositing portion 302 made of a low melting point metal, the linear member 303 is pulled out. Since the linear member 303 has low affinity with the low melting point metal, it can be easily pulled out. By this step, a banking portion in which the holes 304 are formed can be obtained.
FIG. 10 is a diagram showing a temporarily fixed state of the present embodiment. It is obtained by inserting another linear member 305 to be fixed in the hole 304. Fixing is performed by giving plastic deformation by the pressing member to the fixing portion.
According to this embodiment, since the linear member to be fixed is not heated, it can be fixed without being softened or burned, and the fixing portion can be easily formed and a strong joint can be obtained.

The above embodiment shows a simple configuration,
Other forms and examples may be used to obtain a more firmly fixed state.

Hereinafter, other configurations using the present invention will be described.
Reference numeral 400 denotes a fixing portion, 401 denotes a member to be locked, 402 denotes a depositing portion made of a low melting point metal, and 403 denotes a linear member. Reference numeral 404 denotes a pressing member.

The present embodiment is an embodiment suitable when an external force is applied to the linear member 403.
FIG. 11 is a diagram showing a fixed state of the present embodiment.
A support column 501 is provided in front of the fixed portion 400 obtained from the first to fourth embodiments, and a linear member 403 is wound around the support column 501.
When an external force is applied to the linear member 403 wound around the column 501,
A frictional force is also generated between the support column 501 and the linear member 403, and the load applied to the fixed portion is dispersed.
Therefore, it is possible to configure a fixed portion that is strong against external force.

This example is an example for obtaining a stronger bond.
FIG. 12 is a diagram showing a fixed state according to the present embodiment.
In the fixing method according to the present invention, after the plastic deformation by the pressing member 404, the end of the linear member 403 can be left behind from the fixing portion.
When the linear member 403 extended from the fixing part 400 is melted, the surface of the linear member 403 has a substantially ball-like shape larger than the cross section of the linear member at a position close to the depositing part 402 where heat is taken away. An end 502 is formed. Further fixing strength is obtained in such a manner that the end portion 502 is caught on the banking portion 402.
The heat applied to the linear member 403 at the time of melting is partially absorbed by the depositing portion 402, and the burden is reduced.
As a melting means, self-combustion of a linear member by a flame, self-heating by energizing a large current only between a metal plate and a wire end, laser light, infrared irradiation, or the like can be used.

The present embodiment is a fixing method capable of obtaining a stronger fixing state.
FIG. 13 is a diagram showing a fixed state of the present embodiment.
The end of the linear member 403 is bent, and the linear member 403 is formed in a U shape, and the depositing portion 402 made of the low melting point metal is provided so as to fix two portions of the linear member. Is the method.
Furthermore, as shown in FIG. 14, by providing the support column 501 so as to wrap around the U-shaped end, a frictional force is generated between the support column 501 and the linear member 403, and a stronger fixing portion can be obtained. .

FIG. 15 is a diagram showing a fixed state of the present embodiment.
This embodiment is a fixing method in the case where the shape memory alloy wire 504 is more firmly fixed to the electronic substrate 503 which is a fixed portion.
After the shape memory alloy wire 504 is inserted into the through-hole 505 provided in the electronic substrate 503, the depositing portion 402 made of a low melting point metal is formed on the through-hole 505, and after cooling and solidifying the depositing portion 402, the pressing member 404. It is formed by the process of plastically deforming.

In addition to fixing by the metal bank 402, friction between the through-hole 505 and the shape memory alloy wire 504 provides stronger fixation.

The present embodiment is a fixing method suitable when an external force is applied in a certain direction.
FIG. 16 shows a fixing portion of the fixing method according to this embodiment. It is fixed perpendicular to the planned movement direction.
Since the frictional fixing force with respect to the planned movement direction becomes high, it is a strong fixing portion.

The fixing portion according to the present embodiment is an embodiment in the case where the fixing portion is firmly fixed in a limited area.
FIG. 17 shows the first step of the fixing method according to this embodiment.
It arrange | positions so that the fixed part of the temporarily fixed state which made the linear member 403 embed | buried in the metal-plating part 402 by a low melting metal may become the inside of the guide 506. FIG.
FIG. 18 shows a second step of the fixing method according to this embodiment.
Plastic deformation is applied by the pressing member 507 within the guide 506. The guide 506 is plastically deformed with a limited range and shape of the depositing portion. .
FIG. 19 shows a fixing portion to which plastic deformation is given according to the shape of the guide 506 showing the fixing state of the fixing method according to the present embodiment.
In addition, since pressure from the side surface is generated by the guide 506 during plastic deformation, a stronger fixing portion can be formed.
That is, the fixing portion can be arbitrarily set according to the shape of the guide, and can be firmly fixed in a limited space.

This embodiment is an embodiment in which the contact portion of the pressing member is formed in a vertical shape.
FIG. 20 shows the first step of the fixing method according to the present embodiment. The fixing portion in the temporarily fixed state in which the linear member 403 is buried in the metal-welding portion 402 made of a low melting point metal is used as the conical hole portion by the pressing member 508. Provides compositional deformation.
FIG. 21 shows a second step of the fixing method according to the present embodiment, in which the banking portion is plastically deformed so as to spread in a conical hole portion provided in the pressing member 508. At this time, the pressing from the side surface direction is performed in the same manner as in Example 10, so that a stronger fixing portion is obtained.
FIG. 22 shows a fixed state according to this embodiment.
A banking portion having the same shape as the hole portion is formed.
As described above, the shape and properties of the banking portion serving as the fixed portion can be determined by forming the pressing member in an arbitrary shape.

This embodiment relates to an apparatus for performing a fixing method according to the present invention.
FIG. 23 is a schematic view of the fixing device of this embodiment.
A wire rod supply mechanism 601 for supplying a linear member, a low melting point metal supply mechanism 602 for melting and supplying a low melting point metal to a fixing target portion, a temporary fixing mechanism 603 for temporarily fixing the linear member to the fixing target portion, It is a linear member fixing device including a heating mechanism 604 for remelting a melting point metal and a pressing mechanism 605 for applying plastic working after the low melting point metal is solidified.
Hereinafter, the fixing method of the linear member by this apparatus is demonstrated.
The low melting point metal supply mechanism 602 melts and supplies the low melting point metal onto the locked member, thereby forming a deposit portion made of the low melting point metal. Next, the heating mechanism 604 remelts the depositing portion, and the linear member supplied from the wire rod supply mechanism 601 is embedded in the depositing portion by the temporary fixing mechanism 603. After the banking part is cooled and solidified, it is pressed by the pressing mechanism 605 to give plastic deformation to the banking part and fix it.

The mechanisms that perform individual functions such as the temporary fixing mechanism and the melt supply mechanism in these apparatuses do not necessarily have to be disposed at the same location or in the vicinity at the same time for processing. In the case of an automatic machine, a device for conveying a work holding the fixed part may be provided. An apparatus for melting a low melting point metal can use an infrared beam as well as electric heating such as a iron. In addition, a suitable amount of low-melting point metal is solidified in advance in the previous process, and a device that presses and fixes the wire to the fixing part with appropriate elasticity and a device that melts the low melting point again are used in the molten metal. A temporary fixing mechanism that sinks the wire may be used. As shown in FIG. 23, the mechanism that gives plastic deformation may be a pressing mechanism such as a punch, or by pressing with a roller as shown in FIG. 24 (a), or holding like a pliers as shown in FIG. 24 (b). It may be a thing.

In addition, these Examples are illustrations and it is clear that the effect of this invention is acquired even if it uses another form and structure. The wire member is not limited to a wire material, and may be a small coil shape with a small diameter that can be regarded as almost linear, for example, and the wire material cross section may be not only circular but also rectangular. The surface of the linear member may be processed to increase the frictional force.

According to the present invention, a wire member formed of a material difficult to be soldered or brazed or a linear member such as a minute coil is firmly attached to an electronic substrate or a metal plate in a process that is easy to automate. be able to.
In particular, when a shape memory alloy is used as a power mechanism of a small device, it is possible to obtain a fixed portion that can be driven by energization heating and can withstand repeated contraction operations.

Schematic diagram before fixing in Example 1 Schematic state during fixation in Example 1 Schematic diagram and sectional view during fixation in Example 1 Schematic diagram and sectional view of the fixed state in Example 1 Schematic of the fixed state which resists the scheduled movement direction in Example 1. Schematic of the fixed state which resists the scheduled movement direction in Example 1. Schematic of the fixed state in Example 2 State schematic diagram of first step in Example 4 State schematic diagram of second step in Example 4 Schematic of the temporarily fixed state in Example 4 Schematic of the fixed state in Example 5 Schematic of the fixed state in Example 6 Schematic of the fixed state in Example 7 Schematic of the fixed state in Example 7 Schematic of the fixed state in Example 8 Schematic of the fixed state in Example 9 State schematic diagram of first step in Example 10 State schematic diagram of second step in Example 10 Schematic of the fixed state in Example 10 State schematic diagram of first step in Example 11 State schematic diagram of second step in Example 11 Schematic of the fixed state in Example 11 Schematic of the member fixing device of the present invention Schematic which shows the other royal pressure mechanism in the member fixing apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Fixed member, 102 Low melting metal deposit part, 103 Linear member 104 Punch, 201 Electronic substrate, 202 Conductive pattern part, 203 Low melting metal deposit part 204 Shape memory alloy wire, 205 Press member, 301 Fixed member , 302 Plated part 303 Linear member, 304 Hole, 400 Fixed part, 401 Fixed member 402 Low melting point metal plated part, 403 Linear member, 404 Pressing member 501 Post, 502 End, 503 Electronic substrate, 504 Shape memory alloy wire 505 Through hole, 506 Wire 601 Wire supply mechanism, 602 Metal supply mechanism, 603 Temporary fixing mechanism 604 Heating mechanism, 605 Press mechanism

Claims (7)

A step of heating and melting a low-melting-point metal to a fixed member to form a raised portion;
A step of installing a fixing target part of the member in the metal deposit part;
After the heat removal, the step of plastically deforming the banking part with a pressing means;
The fixing method of the member provided with.

A step of heating and melting a low-melting-point metal to a fixed member to form a raised portion;
A step of forming a hole part in the metal deposit part by installing a member of a material having no affinity with the low melting point metal in the metal deposit part, and removing after heat removal;
Inserting a member to be fixed into the hole portion, and plastically deforming the metal deposit portion with a pressing means; and
The fixing method of the member provided with.
The member fixing method according to claim 1, further comprising a step of installing a buffer mechanism for absorbing an external force applied to the fixing portion.
By dissolving the surplus end of the member extending from the fixed part,
The method for fixing a member according to claim 1, further comprising a step of forming an end portion having a larger cross-sectional area than the member.
The plastic deformation step is cold working.
The method for fixing a member according to claim 1.
Consists of a raised portion made of a low melting point metal joined to a fixed member,
The member fixing target part is embedded in the metal deposit part,
A fixed part of a member fixed by applying plastic deformation.
A mechanism for disposing the raised metal portion of the low melting point metal on the fixed member;
A mechanism for melting the metal deposit part;
A mechanism for disposing a member to be fixed in the filling portion;
A member fixing device comprising: a pressing mechanism that presses the metal bank and applies plastic deformation.