JPH07214369A - Joined structure and its manufacture - Google Patents

Abstract

PURPOSE:To provide an inexpensive joined structure and its manufacturing method where the exprosive scattering of the fusion zone is suppressed, and the laser beam welding can be executed in an excellent and stable manner. CONSTITUTION:A joined structure consists of a first member 1 having a laser beam irradiating surface 15 and a second member 2 which is arranged on the opposite side to the laser beam irradiating surface 15 and whose laser beam absorption ratio is higher than that of the first member 1. A first film 11 whose laser absorption ratio is higher than that of the first member 1 is arranged on the laser beam irradiating surface 15 side of the first member 1. A joining layer 3 is interposed between the first member 1 and the second member 2. The joined structure 3 consists of a third film 23 which is arranged on the first member 1 side and whose laser beam absorption ratio is higher than that of the first member 1 or whose melting point is lower than that of the first member 1, and a second film 22 which is arranged on the second member side and whose laser beam absorption ratio is lower than that of the second member or whose melting point is higher than that of the first member 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joining structure used for an integrated circuit, a circuit such as a sensor, or a wiring between a circuit and a case terminal, and in particular, dissimilar metals are superposed and laser-welded. The present invention relates to a bonded structure and a manufacturing method thereof.

[0002]

2. Description of the Related Art Since laser welding uses a heat source with an extremely high energy density, it has a small thermal effect on areas other than the irradiated area
It has the feature that it can weld minute parts and parts that require precision with low distortion. When welding dissimilar metals by using such laser welding, as shown in FIG. 23, the dissimilar metals are generally laminated to each other, and the laser passing through the lens 5 is passed from the side of the first metal member 91 which is difficult to melt by laser. 50 is irradiated to melt-weld the first metal member 91 to the second metal member 92 which is easily melted by the laser.

As shown in FIG. 24, the first metal member 91 on the surface is first melted by this laser input, and the melted portion 99 is, as shown in FIG.
The metal member 92 is reached. As a result, the first and second metal members 91, 92 are welded and joined.

Further, as shown in FIG. 28, the first metal member 91 on the surface is provided with a plating film 911 which is easily melted by laser, and the second metal member 92 thereunder is provided with a plating film 922 for suppressing laser welding, The first and second metal members 91 and 92 may be welded and joined at the fusion zone 99 by laser irradiation.

Next, it can be considered to use the first and second metal members in a welded joint portion of an electronic component. For example, as shown in FIG. 29, the first metal member 910 is used as a lead 170 for taking out electronic information from the circuit board, and the second metal member 920 is integrated with a resin case 790 for housing the circuit board. May be used as.

One end of the terminal terminal 270 has a lead 17 at one end.
It is a welded part 200 with 0, and the other end is a resin case 79.
The connector portion 201 is embedded in 0. The terminal 270 is covered with a Ni plating film 229 having excellent fusion bondability with the lead 170. Then, only the surface of the connector portion 201 is covered with a Sn (tin) plating film 239 in order to improve the durability of electric conduction.

A method of manufacturing a terminal terminal integrated with the resin case 790 will be described with reference to FIG. First, a brass material coated with an Sn plating film is prepared as a material for making terminal terminals. Further, resin is prepared as a material for producing the resin case.

Next, the material for making the terminal terminals is
Pressing into a desired shape using a mold, punching,
The terminal terminal 270 shown in FIG. 29 is obtained. Next, as a surface treatment process, the entire surface of the terminal 270 is
The Ni plating film 229 is formed by the electroless plating method, and then the Sn plating film 239 is formed only on the connector portion 201 of the terminal terminal 270.

Next, the above-mentioned terminal terminals are fixed in predetermined positions in the mold. Then, the softening resin for producing the resin case is injected into the mold to insert-mold the resin case. Next, extra terminal terminals are press-cut and annealed at about 175 ° C. Then,
An insulation test is performed between the terminal 270 and the resin case 790. As a result, a terminal terminal integrated with the resin case can be obtained. After that, this is packed and transported to another place, where the circuit is mounted in the resin case by using the lead 170.

The lead 170 is solder plated 9
It is the 1st metal member 910 made from annealed copper which provided 11. The terminal 270 and the lead 170 are welded and joined by laser irradiation. The thickness of the second metal member 920 is 0.
It is 64-0.8 mm. The electroless Ni plating film 229 has a film thickness of 3.5 μm. The thickness of the Sn plating film 239 is 3 μm.

[0011]

However, as shown in FIG. 26, when the molten portion 99 of the first metal member 91 reaches the second metal member 92 below the second metal member 92, the portion of the second metal member irradiated by the laser is irradiated. 92 may evaporate immediately after irradiation, the molten metal 990 may be blown, and the perforated state 991 may occur. Therefore, if the laser input is reduced to prevent bombardment, as shown in FIG. 27, the molten portion 99 does not reach the second metal member 92, the first metal member 91 is insufficiently melted, and welding is insufficient. Become.

Further, as shown in FIG. 28, when a film is formed on the surfaces of the first and second metal members 91 and 92,
Although the weldability of both members can be improved, the cost is high because an alloy of nickel and phosphorus is used as the plating film 922 that suppresses laser melting. If the plating film 930 is replaced with Sn plating, which has a low cost, the second metal member 92 may be excessively heated by the laser, the molten portion may be blown, and spatter may occur. Therefore, it is difficult to perform good and stable laser welding.

Further, as shown in FIG. 29, when the first and second metal members 91, 92 are used as the lead 170 and the terminal terminal 270, respectively, as described above, the connector portion 201 embedded in the resin case 790.
Must be covered with a tin-plated film 239.
Therefore, as shown in FIG. 30, the terminal terminal 270
At the time of manufacturing, the surface of the second metal member 920 must be subjected to a complicated plating process in two steps.

Therefore, there is a problem that it takes a long time to manufacture the terminal terminal 270 and the cost becomes high. Therefore, in view of such conventional problems, the present invention intends to provide an inexpensive joint structure capable of suppressing the blow-up of the molten portion and performing good and stable laser welding, and a manufacturing method thereof. is there.

[0015]

According to the present invention, there is provided a joining structure comprising a first member having a laser irradiation surface and a second member arranged on the side opposite to the laser irradiation surface and having a laser absorption rate higher than that of the first member. In the body, the laser irradiation surface of the first member,
Disposing a first coating having a higher laser absorption rate than the first member,
A third laser having a higher laser absorptivity between the first member and the second member than the first member disposed on the first member side.
A joining layer comprising a coating and a second coating having a laser absorption rate lower than that of the second member disposed on the second member side is provided, and these are integrally welded by laser welding. It is in the characteristic joint structure.

What is most noticeable in the present invention is that the first film having a high laser absorptivity is provided on the laser irradiation surface of the first member, and that the surface of the first member opposite to the laser irradiation surface is provided. That is, the second member having a higher laser absorptivity than that of the first member is provided via the bonding layer having a two-layer structure having different laser absorptivities for the first member and the second member.

The first member has a lower laser absorption rate than the second member. As the first member, for example, copper, copper alloy,
There are soft copper, oxygen-free copper, etc. As the second member, the above first
Materials having a higher laser absorptivity than members, such as brass, phosphor bronze, mild steel, iron-nickel alloy, and stainless steel, are available.

The first coating coats the laser irradiation surface of the first member. As the first coating, a material having a higher laser absorptivity than the first member, for example, a low melting point material having a higher laser absorption can be used, and as the material, tin, solder (Pb-Sn alloy), lead or the like can be used. There is. The first coating is the first
It is preferable to select an appropriate thickness so as not to accelerate the melting of the member too much and not to overheat the second member. Specifically, it is preferably 1 to 10 μm. If the thickness is less than 1 μm, the heat input by the laser becomes insufficient and the melting becomes difficult to proceed, so that the strength may be insufficient. On the other hand, if the thickness exceeds 10 μm, the molten member may explode.

The joining layer is provided between the first member and the second member. The bonding layer has a two-layer structure, is disposed on the first member side, has a third coating having a higher laser absorptivity than the first member, and is disposed on the second member side, and is more than the second member. The second coating has a low laser absorption rate. As the third coating, a material having substantially the same laser absorptivity as that of the first coating, such as tin, solder, or lead, may be used.

There is no particular problem with the second coating as long as it is a material having a laser absorptivity higher than that of the second member. For example, as the material having a laser absorptivity substantially the same as that of the first member, for example, copper. , Copper alloy, etc. can also be used.

The bonding layer may have the first coating provided between the first member and the third coating in addition to the third coating and the second coating. In addition, the first coating and the third coating may have substantially the same laser absorptance. For example, the same material may be used for both coatings. In this case, in the bonding layer, the first coating is also the third
As with the coating, the progress of the laser input from the first member can be promoted.

It is preferable that the total film thickness of the above-mentioned bonding layer is a film thickness which has an intermediate laser absorptance between the first member and the second member due to melting by laser irradiation. For example, the total thickness of the second coating and the third coating constituting the bonding layer is 2
It is preferably 0 μm or less. As a result, the melting of the bonding layer due to laser irradiation is damped and the second
Since it reaches the member, it is possible to prevent explosion and spatter from being generated due to overheating of the second member, and it is possible to perform good and stable laser welding.

The thickness of the second coating is preferably 0.1 to 1 μm. If less than 0.1 μm, the first
The welding strength between the member and the second member may decrease.
On the other hand, if it exceeds 1 μm, there is a risk of spatter and explosion. The thickness of the third coating is preferably 0.1 to 20 μm. If less than 0.1 μm, or 20
When it exceeds μm, the range of the laser output capable of performing good welding is narrow, and it is difficult to adjust the output.

The laser absorption rate is, for example, a laser absorption rate for an infrared laser. As an infrared laser, Y
An AG laser, a carbon dioxide gas laser, a ruby laser, an argon laser or the like can be used. The bonded structure of the present invention irradiates a laser from the laser irradiation surface,
The member and the second member are welded and joined together via the joining layer. The laser is, for example, the infrared laser shown above.

As a method of manufacturing the above-mentioned bonded structure, for example, a first coating film having a laser absorption rate higher than that of the first member is formed by plating on at least the laser irradiation surface of the first member, and then the first member is formed. A second member having a laser absorptivity higher than that of the second member, and a second member having a laser absorptivity lower than that of the second member is provided on at least the surface of the second member on the first member side.
The coating is formed by plating, and then on the side opposite to the laser irradiation surface of the first member, or on the first member of the second member.
A third coating having a laser absorptivity higher than that of the first member is formed on one or both surfaces of the member by a plating method, and then the first member and the second member are formed on the first member. There is a method of manufacturing a bonded structure, characterized in that the side opposite to the laser irradiation surface and the second coating side of the second member are faced to each other, stacked, and laser-irradiated to integrally bond them. .

In the above manufacturing method, the first member is
After forming the first coating, it can be processed into a desired shape prior to the lamination.

Further, in the present invention, there is a bonding structure using the first coating and the second coating having different melting points instead of the first coating and the second coating having different laser absorptivities as described above. That is, in a joint structure including a first member having a laser irradiation surface and a second member arranged on the side opposite to the laser irradiation surface and having a higher laser absorption rate than the first member,
The first coating having a laser absorption rate higher than that of the first member is disposed on the laser irradiation surface of the first member, and the first coating is provided between the first member and the second member. A third coating film having a melting point lower than that of the first member arranged and a second coating film having a melting point higher than that of the second member arranged on the second member side are provided. Is a joined structure which is integrally welded by laser welding.

The joining layer is a third coating which is disposed on the first member side and has a lower melting point than the first member, and a second coating which is disposed on the second member side and has a higher melting point than the second member. And consists of.
As the third coating, a material having substantially the same melting point as that of the first coating, such as tin, may be used. There is no particular problem as long as the second coating has a lower melting point than that of the second member. For example, copper or the like can be used as the material having substantially the same melting point as that of the first member.

As the third coating, a material having a higher laser absorptivity than the first member and a lower melting point than the first member, such as solder or lead, may be used.
Further, as the second coating, a material having a lower laser absorptivity than the second member and a higher melting point than the second member, for example, copper or copper alloy can be used.

The joining layer may have the first coating provided between the first member and the third coating in addition to the third coating and the second coating. Further, the first coating and the third coating may have substantially the same melting point, and for example, the same material may be used for both coatings. In this case, in the bonding layer, like the third coating, the first coating can promote melting by the laser input from the first member.

It is preferable that the total film thickness of the above-mentioned bonding layer is a film thickness which becomes an intermediate melting point between the first member and the second member due to melting by laser irradiation. As a result, the melting of the bonding layer due to laser irradiation reaches the second member while being damped, so that it is possible to prevent explosion and spatter due to overheating of the second member, and perform good and stable laser welding. be able to. Others are the same as the above-mentioned invention.

As a method of manufacturing the above-mentioned joined structure, for example, a first coating film having a melting point lower than that of the first member is formed by plating on at least the laser irradiation surface of the first member, and then the first member is formed. A second member having a high laser absorptivity is prepared, a second coating film having a high melting point is formed on at least the surface of the second member on the first member side by a plating method, and then a laser irradiation surface of the first member is formed. A third coating having a melting point lower than that of the first member is formed by plating on either or both surfaces of the second member and the first member side of the second member, and then the first member and the first member are formed. The second member and the second member on the side opposite to the laser irradiation surface of the first member.
Face the second coating side of the member, stack,
There is a method of manufacturing a bonded structure, which is characterized by irradiating a laser to bond them integrally.

In the above manufacturing method, the first member is
After forming the first coating, it can be processed into a desired shape prior to the lamination.

As a concrete example of use of the joint structure of the present invention, it is used in an electronic circuit when the connection between the hybrid integrated substrate and the case terminal and the connection between the terminals in the sensor are connected by the copper lead foil. There are circuit connections between printed boards.

[0035]

In the bonded structure of the present invention, the first coating is provided on the laser irradiation surface of the first member. Since the first coating has a higher laser absorption rate than the first member, it enhances the laser absorption of the first member and increases the laser absorption of the first member. Therefore, it is possible to raise the temperature of the first member and accelerate the melting of the first member with a low laser input.

Thus, the laser absorbed by the first member proceeds while further reducing the output, and eventually reaches the back surface side of the first member opposite to the laser irradiation surface. A bonding layer is interposed between the second member and the back surface side of the first member. The bonding layer includes a third coating having a laser absorption rate higher than that of the first member provided on the first member side, and a third coating having a laser absorption rate lower than that of the second member provided on the second member side. 2 coatings.

Therefore, when the laser passes through the joining layer, it first reaches the second member while accelerating the progress in the first coating and then gradually reducing the progress in the second coating. Therefore, the laser is incident on the second member to the extent that it can be welded to the first member and does not excessively melt while maintaining a certain output.

As a result, no explosion or spatter is generated,
The first member and the second member can be laser-welded with good stability in a small laser output. Furthermore, since inexpensive materials are used for the first, second, and third coatings that cover the first and second members, the cost of the bonded structure can be reduced. Further, according to the method for manufacturing a bonded structure of the present invention, it is possible to manufacture a bonded structure having excellent characteristics as described above.

Next, when the third coating and the second coating having different melting points from those of the above-mentioned first and second members are used as the bonding layer, when melting the bonding layer by laser, first, The melting speed of the first coating is once increased, and then the progress of the second coating is gradually reduced to reach the second member. Therefore, the melting by the laser reaches the second member to such an extent that the second member can be welded to the first member and is not excessively melted while maintaining a certain speed.

As a result, no explosion or spatter is generated,
The first member and the second member can be laser-welded with good stability in a small laser output. In addition, also in the present invention, the same effects as described above can be obtained. As described above, according to the present invention, it is possible to suppress the explosion of the fusion zone,
It is possible to provide an inexpensive joint structure capable of performing favorable and stable laser welding and a method for manufacturing the same.

[0041]

【Example】

Example 1 A joint structure according to an example of the present invention is shown in FIGS.
Will be explained. As will be described later, the joint structure of this example shows a structure in which a lead and a terminal terminal of an electronic component are joined, and the lead constitutes the first member and the terminal constitutes the second member. That is, as shown in FIG. 1, the bonded structure of this example is arranged on the first member 1 having a laser irradiation surface 15 and on the opposite side of the laser irradiation surface 15, and has a laser absorption rate higher than that of the first member 1. Of the second member 2 having a high height.

The entire surface of the first member 1 is covered with a first coating 11 having a laser absorption rate higher than that of the first member 1. The second coating 22 and the third coating 22 are formed on both front and back surfaces of the second member 2.
It is covered with the coating 23. The second coating 22 has a lower laser absorptivity than the second member 2, and the third coating 23 has a higher laser absorptivity than the first member 1.

The first member 1 and the second member 2 are laminated with the bonding layer 3 interposed therebetween. The first coating 11, the third
The coating film 23 and the second coating film 22 form the bonding layer 3. The surface of the first member 1 opposite to the second member 2 is used as a laser irradiation surface 15, the YAG laser 50 is irradiated from the laser irradiation surface 15, and the second member 2 is interposed via the bonding layer 3.
And laser welded.

The first member 1 is a lead in one electronic component and is made of copper or copper alloy. The second member 2 is a terminal terminal in the other electronic component, and is made of brass or mild steel having a higher laser absorptivity and a lower laser reflectivity than copper. The first coating 11 and the third coating 23 are tin coatings having a higher laser absorptivity than the first member 1, for example, having a low melting point. The second coating 22 is a coating of copper having a lower laser absorptivity than the second member 2 or a higher melting point than the second member 2. Table 1 shows the laser absorptivities and melting points of the above-mentioned materials used for the first member, the second member, the first coating, the second coating, and the third coating.

[0045]

[Table 1]

The thickness of the first coating 11 is 1 to 10 μm, and the thickness of the third coating 23 is 10 μm or less. The total thickness of the first coating 11 and the third coating 23 that cover the back surface of the first member 1 is 20 μm or less. The thickness of the second coating 22 is 0.1 to 1 μm. The thickness of the third coating 23 is 1
Is about 4 μm. The total film thickness of the bonding layer 3 composed of the first film 11, the third film 23, and the second film 22 is determined by melting due to laser irradiation, and the laser absorption rate in the middle between the first member 1 and the second member 2. (1 to 20 μm).

Next, a method for manufacturing the above bonded structure will be described. First, as shown in FIG. 1, the first coating 11 is formed on both front and back surfaces of the first member 1 by electroplating.
A second coating 22 is applied as a base plating on one surface of the second member 2, and a third coating 23 is coated on the surface of the second coating 22 by electroplating. Next, the first member 1
The second member 2 and the second member 2 are overlapped and laminated, and these are integrally bonded by laser irradiation to manufacture a bonded structure of this example.

That is, in the above bonded structure, the condenser lens 5 is formed on one surface of the first member 1 as the laser irradiation surface 15.
After that, the YAG laser 50 is irradiated. As a result, first, as shown in FIG. 3, the laser irradiation surface 15 of the first member 1 is
The vicinity of the surface of is melted, and a melted portion 19 is formed. Eventually, the fusion zone 19 reaches the bonding layer 3 as shown in FIG. Then, the fusion zone 19 further reaches near the surface of the second member 2 as shown in FIG. Thereby, as shown in FIG. 2, the first member 1 and the second member 2 are laser-welded at the welded portion 19 formed on the first member 1, the bonding layer 3 and the second member 2.

Next, the function and effect of this example will be described.
In the bonded structure of this example, as shown in FIG. 1, the first coating 11 is provided on the laser irradiation surface 15 of the first member 1. Since the first coating 11 has a higher laser absorption rate than the first member 1, it enhances the laser absorption of the first member 1. Therefore, as shown in FIG. 3, it is possible to raise the temperature of the first member 1 and accelerate the melting of the first member 1 with a low laser input.

Then, the laser absorbed by the first member 1 proceeds while further reducing the output, and eventually reaches the back surface side of the first member 1 opposite to the laser irradiation surface 15.
As shown in FIG. 4, on the back surface side of the first member 1, between the second member 2 and the first coating film 11 and the second coating film 22 disposed on the first member 1 side, and the second member side. Second coating 2 disposed on
The bonding layer 3 composed of 2 is interposed.

The first coating film 11 and the third coating film 23 are made of tin and have a higher laser absorption rate than the first member and a melting point lower than that of the first member. On the other hand, the second coating 2
2 is copper, which has a lower laser absorption rate than the second member,
It has a higher melting point than the second member.

Therefore, when the laser passes through the bonding layer 3, as shown in FIG. 4, the progress of the laser is first accelerated in the first coating film 11 and then gradually reduced in the second coating film 22, 2 Reach the member 2. Therefore,
The laser maintains the output to some extent, and the second member 2
Injects to the first member 1 to such an extent that it can be welded to the first member 1 and does not melt excessively.

The third coating 23 has a lower melting point than the second member 2 and the first and third coatings 11, 23 have a lower melting point than the first member 1. Therefore, as shown in FIG. When the bonding layer 3 melts, first, the melting speed of the first coating 11 is once increased, and then the progress of the second coating 22 is gradually reduced to reach the second member 2. Therefore, the laser melting reaches the second member 2 to such an extent that it can be welded to the first member 1 and does not excessively melt while maintaining a certain speed.

As a result, as shown in FIGS. 2 and 5, the first member 1 and the second member 2 can be laser-welded satisfactorily and stably without generation of bombs or spatters and with a small laser output. You can

Further, as shown in Table 1, the total film thickness of the bonding layer 3 is a film having an intermediate laser absorption rate between the first member 1 and the second member 2 due to melting by laser irradiation.
Therefore, the melting of the bonding layer 3 due to the laser irradiation reaches the second member 2 while being braked, so that the second member 2
It is possible to prevent explosion and spatter due to overheating.

Further, since the first coating 11 and the third coating 23 are made of the same material, both the coatings can accelerate the progress of the laser input from the first member 1 and the melting rate by the laser. Furthermore, since the first, second, and third coatings 11, 22, and 23 that coat the first and second members 1 and 2 are made of inexpensive materials, the cost of the bonded structure can be reduced. You can

Further, according to the manufacturing method of this example, it is possible to manufacture a bonded structure having excellent characteristics as described above.

Example 2 In this example, as shown in FIG. 6, both members when the film thickness (L) and the laser output (J) of the first coating and the third coating in the joining layer were variously changed. The bonding state of was measured. In this measurement, the same bonded structure as in Example 1 was used. The film thickness (L) is, as shown in FIG. 7, the total thickness (μm) of the first film 11 and the third film 23 having various thicknesses. The first coating 11 and the third coating 23 are both the first
The tin coating has a higher laser absorption rate than the material of the member 1.

The results of the measurement are shown in FIG. From the figure,
It can be seen that when the film thickness (L) is in the range of 5 to 15 μm, stable welding can be performed with the widest laser output. Further, when the film thickness exceeds 15 μm, the molten metal 190 explodes as shown in FIG.
The perforated state 991 is likely to occur. This is because the tin used in the first coating 11 and the third coating 23 has a high laser absorptivity and a low melting point with respect to the first member 1, so that the molten portion was excessively heated by the laser irradiation. Is considered to be.

On the other hand, when the total film thickness (L) of the first film and the third film is 0, the second film 22 acts as if to stop the melting, but in this case, the second film is melted. Member 2
More laser power is required to reach
Therefore, if the laser output is increased, the joining state will be good for a while when the output reaches a certain range. However, the range is very narrow, and if the laser output is made too high even slightly, the molten metal 190 is blown and a perforated state 991 occurs as shown in FIG. Therefore, it can be seen that when the film thickness (L) is 0, it is very difficult to adjust the laser output.

Embodiment 3 As shown in FIG. 9, in the joint structure of this embodiment, only the surface of the second member 2 facing the first member 1 is covered with the second coating 22 and the third coating 23. . The second coating film 22 and the third coating film 23 constitute the bonding layer 3 together with the first coating film 11 coating the surface of the first member 1. Others,
This is the same as in the first embodiment. Also in this example, the same effect as that of the first embodiment can be obtained.

Example 4 As shown in FIG. 10, the bonded structure of this example has the first member 1
The surface of the second member 2 is covered with the first coating 113.
The second coating 22 is formed only on the surface facing the first member 1 in FIG.
Is covered. A bonding layer 3 including a first coating 113 and a second coating 22 is interposed between the first member 1 and the second member 2. The first coating 113 is tin,
Its thickness is 1 to 10 μm. Others are the same as in the first embodiment.

In this example, the first coating 113 that covers the surface of the first member 1 facing the second member 2 is the same as in the first embodiment.
Plays the same role as the third coating used in. Therefore, also in this example, as in the first example, good and stable laser welding can be performed without the occurrence of bombing and spatter. When the thickness of the first coating 113 was less than 1 μm, a high laser input tended to be required. On the other hand, when the thickness exceeds 10 μm, the frequency of explosion and spatter increases.

Fifth Embodiment As shown in FIG. 11, the bonded structure of this embodiment has the first member 1
The first coating 11 is applied only to the laser-irradiated surface 15.
Between the first member 1 and the second member 2, a bonding layer 3 composed of a third coating 23 and a second coating 22 is interposed.
The thickness of the first coating 11 is 1 to 10 μm. The thickness of the second coating 22 is 0.2 to 0.8 μm. Third coating 2
The thickness of 3 is 1 to 4 μm. Others are the same as in the first embodiment. Also in this example, the same effect as that of the first embodiment can be obtained.

Example 6 As shown in FIG. 12, the bonded structure of this example has the first member 1
Both the front and back surfaces are covered with the first coating 11. Further, the second coating film 22 and the third coating film 23 are formed only on the surface of the second member 2 facing the first member 1.
The first coating 1 is provided between the first member 1 and the second member 2.
The bonding layer 3 composed of the first coating film 22, the second coating film 22, and the third coating film 23 is interposed. Others are the same as in the first embodiment. Also in this example, the same effect as that of the first embodiment can be obtained.

Example 7 As shown in FIG. 13, the joining structure of this example has the first member 1
The first coating 11 is formed only on the laser irradiation surface 15. Further, the second coating film 22 and the third coating film 23 are formed only on the surface of the second member 2 facing the first member 1. Between the first member 1 and the second member 2, a joining layer 3 composed of the second coating film 22 and the third coating film 23 is provided.

The thickness of the first coating 11 is 1 to 10 μm. The thickness of the second coating 22 is 0.2 to 0.8 μm. The third coating 23 has a thickness of 1 to 4 μm. Others are the same as in the first embodiment. Also in this example, Example 1
The same effect as can be obtained.

Embodiment 8 As shown in FIG. 14, the bonded structure of this embodiment has the first member 1
The first coating film 11 is formed on both front and back surfaces. Further, on the side of the first member 1 facing the second member 2, the third coating film 13 having a thickness of 1 to 4 μm is formed on the surface of the first coating film 11.
Are formed.

Further, the second coating 22 is formed only on the surface of the second member 2 facing the first member 1. Others are the same as in the first embodiment. Also in this example, Example 1
The same effect as can be obtained.

Example 9 The joint structure of this example has the first member 1 as shown in FIG.
The third coating 113 made of the same material as the first coating 11 on both front and back surfaces of
Are formed. A second coating 22 is formed on the surface of the second member 2 facing the first member 1. The first and third coatings 11 and 113 are simultaneously formed by electroplating.

The thickness of the first coating 11 is 1 to 10 μm. The thickness of the second coating 22 is 0.2 to 0.8 μm. The thickness of the third coating 113 is 1 to 4 μm. Others are the same as in the first embodiment. Also in this example, the same effect as that of the first embodiment can be obtained.

Example 10 As shown in FIG. 16, the joining structure of this example has the first member 1
The first coating film 11 is formed on both front and back surfaces. Further, on the side of the first member 1 facing the second member 2, the first member
A third coating 13 having a thickness of 1 to 4 μm is formed on the surface of the coating 11.

A second coating 22 is formed on both front and back surfaces of the second member 2. Further, a third coating 23 is formed on the surface of the second member 2 opposite to the surface facing the second member 2 in order to improve the durability of electric conduction of the connector portion. Others are the same as in the first embodiment. Also in this example, the same effect as that of the first embodiment can be obtained.

Example 11 As shown in FIG. 17, the joining structure of this example has the first member 1
The first coating film 11 is formed on both front and back surfaces of the. Also, the second
A second coating 22 is formed on both front and back surfaces of the member 2. Furthermore, a third coating 231 is formed on the surface of the second coating 22 formed on the surface of the second member 2 that does not face the first member 1 in order to improve the durability of the electrical conduction of the connector portion.

The thickness of the first coating 11 is 1 to 10 μm. The thickness of the second coating 22 is 0.2 to 0.8 μm. The thickness of the third coating 231 is 1 to 4 μm. Others are the same as in the first embodiment. Also in this example, the same effect as that of the first embodiment can be obtained.

Embodiment 12 As shown in FIGS. 18 to 22, the joint structure of this embodiment is an example used for electrical connection between a HIC circuit in an electronic component and a case-integrated terminal terminal. As shown in FIG. 18, the bonding structure includes a first member 10 having both surfaces covered with a first coating 110, and a second member 20 having both surfaces coated with a second coating 220 and a third coating 230.
And consists of.

The first member 10 and the second member 20 are welded to each other by overlapping a part of them and irradiating the YAG laser 50 from the laser irradiation unit 100 of the first member 10. The first coating 110, the third coating 230, and the second coating 220 form the bonding layer 3.

As shown in FIGS. 18 and 19, the first coating 1
The first member 10 provided with 10 is a lead 17. The second film having the second film 220 and the third film 230 applied thereto
The member 20 is a terminal terminal 27 formed integrally with the case 79. The first member 10 is annealed copper and has a thickness of 90 to 150 μm. The first coating 110 is a solder plating film (Pb-Sn) and has a thickness of 1 to 10 μm.
m.

The second member 20 is brass and has a thickness of 0.64 to 0.8 mm. The second coating 220 is Cu
(Copper) Underlayer plating film, the thickness is 0.3-0.8
μm. The third coating 230 is a finish Sn (tin) plating film and has a thickness of 0.5 to 1.5 μm. Table 2
In addition, the first member 10, the first coating 110, the second member 2
The materials of 0, the second coating 220, and the third coating 230, and their laser absorptance and melting point are shown.

[0080]

[Table 2]

The lead 17 and the terminal terminal 27 are
As shown in FIG. 19, it is a component of the electronic component 7 and is used for connection between the hybrid integrated circuit board 70 (hereinafter referred to as “HIC board”) and the case 79. One end of the terminal 27 is connected to the case 7 of the electronic component 7.
9 is embedded in the case 9, and one end of the case 79 is projected from the inner wall of the case 79. The HIC board 70 is fixed inside the case 79.

A semiconductor chip 75 is mounted on the HIC substrate 70.
1, 752, and a ceramic substrate 71 are mounted, and these are electrically connected by a wiring circuit 73. The ceramic substrate 71 and the terminal terminal 27 are electrically connected by the lead 17. The lead 17 is connected to the terminal terminal 2 at the welded portion 100.
7 and laser welded. Also, the lead 17 is
As shown in FIG. 20, the welded portion 101 is welded to the 42-alloy pad 711 fixed to the ceramic substrate 71 by the solder 710.

FIG. 20 shows a method of manufacturing the above electronic component.
~ It demonstrates using FIG. First, as shown in FIG. 21, a brass material coated with a tin plating film is prepared as a material for producing a terminal terminal. In addition, resin is prepared as a material for making the case.

Next, the material for producing the terminal terminals is
Pressing into a desired shape using a mold, punching,
Get terminal terminals. Then, the terminal terminals are fixed at predetermined positions in the mold. Next, the softening resin for making the case is injected into the mold to insert-mold the case.

Next, extra terminal terminals are press-cut and annealed at about 175.degree. Then, the insulation between the terminal and the case is inspected. As a result, a case-integrated terminal terminal is obtained. In some cases, the terminal terminals integrated with the case are then packaged and transported to another place, where the following steps are performed.

Next, as shown in FIG. 22, the HIC board 70 is mounted inside the case 79. On the other hand, a brass material with a solder plating film is formed into a desired shape,
Obtain the lead 17. Next, as shown in FIG. 20, the lead 17 and the terminal terminal 27 are welded to each other at the welded portion 100 by laser irradiation. In addition, the lead 17 and the pad 711 of the HIC board 70 are connected to the welded portion 10
Welding is performed at 1. As a result, the electronic component 7 shown in FIG. 19 is obtained.

The operation and effect of this example will be described. In this example, as the material of the terminal terminal 27, the base Cu
The brass coated with the plating film and the Sn plating film is used. Therefore, the material of the terminal terminal can be standardized.

Further, unlike the conventional case, the welded portion 200 of the terminal terminal 27 and the connector portion 201 can be formed with the same coating composition, and it is not necessary to form them with different plating structures as in the conventional case (see FIG. 30). ). Therefore, the plating process after pressing and punching can be eliminated, and the cost can be reduced.

Since the second and third coatings 220 and 230 can be formed by using the second coating 220 as an undercoat,
Low melting point plating material produced by such plating method,
For example, the product can be formed by pressing a tin-plated brass plate. Therefore, there is no need to perform plating in the next process after pressing, and it can be expected to simplify the process. Other than that, the same effects as those of the first embodiment can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view of a bonded structure of Example 1 before laser welding.

FIG. 2 is a perspective view of an essential part of the fusion-bonded joint structure according to the first embodiment.

FIG. 3 is an explanatory diagram showing a molten state of the first member when the bonded structure of Example 1 is irradiated with laser.

FIG. 4 is an explanatory view showing a melted state of the first member and the bonding layer, following FIG.

FIG. 5 is an explanatory view showing a state in which the first member and the second member are fusion-bonded, following FIG. 4;

FIG. 6 is a graph showing the results of measuring the welding state of the bonded structure with respect to the film thickness of the bonding layer and the laser output in Example 2.

FIG. 7 is an explanatory diagram showing a melted portion of Example 2 in a perforated state.

FIG. 8 is an explanatory diagram showing a melted portion in a perforated state when the coating thickness L is 0 in Example 2.

FIG. 9 is an explanatory cross-sectional view of the joint structure of Example 3 before laser welding.

FIG. 10 is a cross-sectional view of the bonded structure of Example 4.

FIG. 11 is a cross-sectional view of the bonded structure of Example 5.

FIG. 12 is a cross-sectional view of the bonded structure of Example 6.

FIG. 13 is a cross-sectional view of the bonded structure of Example 7.

14 is a cross-sectional view of the bonded structure of Example 8. FIG.

FIG. 15 is a cross-sectional view of the bonded structure of Example 9.

FIG. 16 is a cross-sectional view of the bonded structure of Example 10.

FIG. 17 is a cross-sectional view of the bonded structure of Example 11.

FIG. 18 is a cross-sectional view of the bonded structure of Example 12.

FIG. 19 is a perspective view of an electronic component according to a twelfth embodiment.

FIG. 20 is an explanatory diagram showing a joined state of the terminal terminal and the ceramic substrate according to the twelfth embodiment.

FIG. 21 is a process explanatory view showing the manufacturing method of the case-integrated terminal terminal according to the twelfth embodiment.

FIG. 22 is an explanatory diagram showing a method of mounting the HIC substrate in the case and electrically connecting the both by leads according to the twelfth embodiment.

FIG. 23 is a cross-sectional view of a conventional bonded structure.

FIG. 24 is an explanatory view showing a molten state of a metal member when laser irradiation is performed in a bonded structure of a conventional example.

FIG. 25 is an explanatory view showing a state in which the joining structure body is fusion-joined in the conventional example.

FIG. 26 is an explanatory view showing a conventional bonded structure in a perforated state.

FIG. 27 is an explanatory view showing a joint structure with a poor joint in the conventional example.

FIG. 28 is an explanatory view showing a state in which the joining structure of another conventional example is fusion-joined.

FIG. 29 is an explanatory diagram showing a usage example in which another conventional joining structure is used as a resin case-integrated terminal terminal and a lead.

FIG. 30 is a process explanatory view showing a method of manufacturing a terminal terminal of another conventional example.

[Explanation of symbols]

 1,10. ． ． First member, 11, 113, 110. ． ． First coating, 13, 23, 230. ． ． Third coating, 15. ． ． Laser irradiation surface, 17. ． ． Reed, 19. ． ． Fusion zone, 2, 20. ． ． Second member, 22, 220. ． ． Second coating, 27. ． ． Terminal terminal, 3. ． ． Bonding layer,

Claims (27)

[Claims] 1. A joint structure comprising a first member having a laser irradiation surface and a second member arranged on the side opposite to the laser irradiation surface and having a laser absorption rate higher than that of the first member. A first coating having a laser absorption rate higher than that of the first member is disposed on the laser irradiation surface of the first member, and is disposed on the first member side between the first member and the second member. A third coating film having a higher laser absorptivity than the first member, and a second coating film having a lower laser absorptivity than the second member disposed on the second member side. These are joined structures characterized by being integrally welded by laser welding. 2. The total film thickness of the bonding layer according to claim 1, when the bonding layer is melted by laser irradiation,
A bonded structure having a film thickness that provides an intermediate laser absorption coefficient between the first member and the second member. 3. The bonded structure according to claim 1, wherein the first coating and the third coating have substantially the same laser absorptance. 4. The bonded structure according to claim 1, 2, or 3, wherein the second coating and the first member have substantially the same laser absorptance. 5. A joint structure comprising a first member having a laser irradiation surface and a second member arranged on the side opposite to the laser irradiation surface and having a laser absorption rate higher than that of the first member. The first coating having a higher laser absorption rate than the first member is disposed on the laser irradiation surface of the first member, and is disposed on the first member side between the first member and the second member. A third coating having a lower melting point than the first member and a second coating having a higher melting point than the second member disposed on the second member side are provided. A joint structure characterized by being integrally welded by welding. 6. The total film thickness of the bonding layer according to claim 5, when the bonding layer is melted by laser irradiation,
A bonding structure having a film thickness that is an intermediate melting point between the first member and the second member. 7. The bonded structure according to claim 5, wherein the first coating and the third coating have substantially the same melting point. 8. The bonded structure according to claim 5, 6, or 7, wherein the second coating and the first member have substantially the same melting point. 9. The bonding layer according to claim 1, wherein the bonding layer is interposed between the first member and the third coating, in addition to the third coating and the second coating. A bonded structure having a first coating. 10. The joint structure according to claim 1, wherein the first coating film is tin, solder, or lead. 11. The method according to any one of claims 1 to 9 or 10,
The thickness of the said 1st film | membrane is 1-10 micrometers, The joining structure characterized by the above-mentioned. 12. The joint structure according to claim 1, wherein the third coating film is tin, solder, or lead. 13. The bonded structure according to claim 1, wherein the thickness of the third coating film is 0.1 to 20 μm. 14. The bonded structure according to claim 1, wherein the second coating film is copper or a copper alloy. 15. The bonded structure according to claim 1, wherein the second coating has a thickness of 0.1 to 10 μm. 16. The bonded structure according to claim 1, wherein the total thickness of the second coating and the third coating is 20 μm or less. 17. The bonded structure according to claim 1, wherein the first member is copper, a copper alloy, mild steel, or oxygen-free copper. 18. The joint structure according to claim 1, wherein the second member is brass, phosphor bronze, mild steel, iron nickel alloy, or stainless steel. 19. The bonded structure according to claim 1, wherein the laser absorption rate is a laser absorption rate for an infrared laser. 20. The method according to claim 1, wherein the first member is copper or a copper alloy, and the second member is brass or mild steel, not only the laser irradiation surface of the first member. A bonding structure, wherein a first coating is provided on the side opposite to the laser irradiation surface, the first coating and the third coating are tin, and the second coating is copper. 21. The laser irradiation surface of claim 1, wherein the first member is annealed copper and the second member is brass. The first coating is also provided on the opposite side,
A joint structure, wherein the first coating is solder, the second coating is copper, and the third coating is tin. 22. The joint structure according to claim 1, wherein the joint structure is irradiated with a laser from the laser irradiation surface to weld the first member and the second member through the joint layer. A joined structure characterized by being joined. 23. The laser according to claim 22, wherein the laser is
A bonded structure characterized by being an infrared laser. 24. A first coating having a laser absorption rate higher than that of the first member is formed on at least a laser irradiation surface of the first member by a plating method, and then a second member having a laser absorption rate higher than that of the first member. Is prepared, a second coating film having a laser absorption rate lower than that of the second member is formed on at least the surface of the second member on the first member side by a plating method, and then,
A third coating having a laser absorptivity higher than that of the first member is formed by plating on either the surface opposite to the laser irradiation surface of the first member, the first member side of the second member, or both surfaces. Then, the first member and the second member are laminated with the side opposite to the laser irradiation surface of the first member and the side of the second coating of the second member facing each other, and laser-irradiated, A method for manufacturing a bonded structure, which comprises integrally bonding these. 25. The method for manufacturing a bonded structure according to claim 24, wherein the first member is formed into a desired shape prior to the stacking after forming the first coating. 26. A first coating having a melting point lower than that of the first member is formed on at least the laser irradiation surface of the first member by a plating method, and then a second member having a higher laser absorption rate than the first member is prepared. Then, a second coating film having a high melting point is formed on at least the surface of the second member on the first member side by a plating method, and then, on the opposite side of the laser irradiation surface of the first member or in the second member. A third coating having a melting point lower than that of the first member is formed on one or both surfaces of the first member by a plating method, and then the first member and the second member are provided with a laser in the first member. A method for manufacturing a bonded structure, characterized in that the side opposite to the irradiation surface and the side of the second coating of the second member are faced to each other, laminated, and laser-irradiated to integrally bond them. 27. The method for manufacturing a joined structure according to claim 26, wherein the first member is formed into a desired shape prior to the stacking after forming the first coating.