JP2003197982A - Gold-tin joint peltier element thermoelectric conversion module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gold-tin joint Peltier element thermoelectric module that is useful for lead-free soldering and preventing out-of-collimation of a laser diode as the entire optical communication module. <P>SOLUTION: A thermomodule 10 comprises a plurality of pair joints of a p-type thermoelectric semiconductor element 13a and an n-type thermoelectric semiconductor element 13b between a ceramic substrate 11 on a heat radiation side and a ceramic substrate 12 on a cooling side. A plurality of independent lands 111 and 121 are respectively formed on the surface of one of the ceramic substrates 11 and 12. Gold-tin layers 113 and 123 are respectively interposed for interconnection between the pairs of p-type thermoelectric semiconductor element 13a and n-type thermoelectric semiconductor element 13b and the land 111 of the ceramic substrate 11 and the land 121 of the ceramic substrate 12. The gold-tin layers 113 and 123 uses a gold-tin eutectic composition solder containing approximately 80 wt.% of gold. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Peltier element thermoelectric conversion module of a small size used for precise temperature control of a laser diode of an optical communication module. The present invention relates to a gold-tin junction Peltier element thermoelectric conversion module having a junction structure that is useful for making free and preventing laser diode optical axis shift.

[0002]

2. Description of the Related Art FIG. 28 shows a thermo module (Peltier device thermoelectric conversion module) used for various temperature control.
It is a conceptual diagram which shows the general structure of 80.

The thermo module 80 includes a P-type thermoelectric semiconductor element 13a containing bismuth and tellurium as main components and an N-type thermoelectric semiconductor element 1 between the ceramic substrates 11 and 12.
3b is joined so as to be connected in series by an electric circuit.

The performance of the thermo module 80 is determined by the performance and size of the P-type and N-type thermoelectric semiconductor elements 13 (13a, 13b) themselves, the number of pairs of thermoelectric semiconductor elements 13 to be incorporated, and the like.

When a direct current is applied to the thermo module 80 through a lead wire 15 (or a metallic post) described later, one end face (for example, the substrate 12) is cooled and the other end face (the same substrate 11) is cooled. It has the property of being heated.

Usually, a pattern (land portion 111) is formed on one surface (pattern surface) of a ceramic substrate 11 made of alumina or aluminum nitride by a method such as plating, and the P-type thermoelectric semiconductor element 1 is formed on each independent land portion 111.
3a and N-type thermoelectric semiconductor element 13b are mounted in pairs.

A similar pattern (land 121) is also formed on the other ceramic substrate 12, but this pattern has all the thermoelectric semiconductor elements 13 after bonding.
The pattern is such that a and 13b are arranged in series in an electric circuit.

Further, on one ceramic substrate (the substrate 11 in this example), a lead member mounting land portion 112-1 for attaching the lead wire 15 for supplying power or a metal post (not shown) to the thermo module 80 is provided. , 112-2
There is.

Usually, the lead member mounting land portion 112 is formed.
After attaching a lead wire 15 or a lead member such as a metal post to -1, 112-2, whether a desired temperature difference is generated by applying a predetermined current value, it is abnormal by repeating reversal energization for several cycles. Tests have been conducted to see if there is a rise in internal resistance.

In recent years, this type of thermo module 80 has been widely used for precise temperature control of laser diodes used for optical communication by utilizing the above-mentioned properties (one substrate generates heat and the other substrate cools).

In such an application, the thermo module 8
0 is usually a butterfly PK with a laser diode
It is housed in a case made of a metal having a low coefficient of thermal expansion called G or the like, and the case and the heat radiation side substrate 11 of the thermo module 80 are soldered.

Further, the laser diode is directly attached to the upper side of the cooling side substrate 12 of the thermo module 80 by solder bonding or adhesive bonding, or is soldered on a heat spreader (metal having a low coefficient of thermal expansion such as copper-tungsten alloy). Mounted by joining.

On the other hand, in the thermo module 80, solder is also used for joining the P-type thermoelectric semiconductor element 13a and the N-type thermoelectric semiconductor element 13b to the lands 111 and 121 of the ceramic substrates 11 and 12.

As the assembly solder in this case, normally,
Lead-tin eutectic solder (melting point 183 ° C) or tin-antimony solder (melting point 232 ° C) is used.

Therefore, when the thermo module 80 is to be incorporated into the package of the optical communication module, the solder used for joining the heat radiation side substrate 11 and the cooling side substrate 12 of the thermo module 80 to the package and the heat spreader is , The melting point of the thermomodule 80 must be lower than that of the assembling solder.

As an example, in the latter thermo module 80 assembled with tin antimony solder, solder having a melting point lower than that of lead-tin eutectic solder can be used for joining with a package or a heat spreader.

On the other hand, in recent years, lead-free solder has been taken up as one of the global environmental problems, and realization of lead-free solder has been an issue in the optical communication field.

Against this background, when the thermo module itself is assembled with tin antimony solder, the lead-free of the thermo-module 80 can be achieved, but in order to achieve the lead-free of the entire package, There is a problem that lead-tin eutectic solder cannot be used and only a part of low melting point solder such as indium tin solder can be used for joining between the laser diode and the heat spreader and joining between the heat spreader and the thermo module.

Therefore, it is necessary to assemble the thermo module 80 with a solder having a temperature higher than that of tin antimony solder and raise the temperature range of the solder that can be used for the package.

On the other hand, the existing solder material has a low Young's modulus and has a characteristic that it easily creeps during long-term use. This property has an advantage that when the materials having different coefficients of thermal expansion are combined, the solder layer serves as a cushioning material to reduce the deformation of the thermo module 80, but also has a demerit that the thermo module 80 gradually deforms after long-term use. is there.

Particularly, in the thermo-module 80 used for precise temperature control of the laser diode, in the current structure in which the laser module is easily deformed due to the temperature change, the optical axis of the laser diode is easily deviated. In order to suppress the deviation, a solder material having a higher Young's modulus has been desired.

[0022]

As described above, the conventional thermomodule described above includes the ceramic substrate, the P type and the N type.
Since it was common to bond lead-tin eutectic solder between thermoelectric semiconductor elements, when using it for temperature control of a laser diode for optical communication, mount the module and laser diode together. However, there was a problem in that it would hinder the lead-free process seen from the entire optical communication module.

Further, in the conventional thermomodule of this type, since the lead-tin eutectic solder used as a bonding agent has a low Young's modulus, the substrate is easily deformed due to temperature change, and the laser diode of the optical communication module is used. When used for precision temperature control, there is a problem that the optical axis of the laser diode is likely to be displaced due to deformation due to temperature change.

The present invention solves the above-mentioned problems, and when used for precise temperature control of a laser diode of an optical communication module, it is a lead-free material as seen from the entire optical communication module and is useful for preventing optical axis shift of the laser diode. An object is to provide a tin-junction Peltier device thermoelectric conversion module.

[0025]

In order to achieve the above object, the invention according to claim 1 provides a plurality of P-type thermoelectric semiconductor elements and N-type thermoelectric semiconductor elements, and the P-type thermoelectric semiconductor elements and N-type thermoelectric semiconductor elements. It has a plurality of metallized layers on which semiconductor elements are mounted one by one, and is bonded to both upper and lower sides of each thermoelectric semiconductor element so that the thermoelectric semiconductor elements are electrically connected in series through the corresponding metallized layers. A pair of ceramic substrates and a lead wire or a metal post for supplying power, which is joined to a lead member mounting metallization layer provided on one side of the ceramic substrate, and the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element are provided. And a metallization layer of the pair of ceramic substrates are bonded together using a gold-tin eutectic composition bonding agent having a gold content of about 80% by weight. The features.

According to a second aspect of the present invention, in the above-mentioned first aspect of the invention, as the bonding agent, a paste having a gold-tin eutectic composition with a gold content in the solid content of about 80% by weight is used for the ceramic substrate. The metallization layer and the thermoelectric semiconductor elements corresponding to the paste are arranged in advance, and the paste is heated and melted to bond the metallized layer and the thermoelectric semiconductor elements with gold-tin. And

According to a third aspect of the present invention, in the above-mentioned first aspect of the present invention, as the bonding agent, gold-tin pellets having a gold content of about 80% by weight are arranged in the metallized layer of the ceramic substrate, The respective thermoelectric semiconductor elements corresponding to the gold-tin pellets are arranged and the gold-tin pellets are heated and melted, whereby gold-tin bonding is performed between the metallized layer and the thermoelectric semiconductor elements.

According to a fourth aspect of the present invention, in the invention according to the first aspect, a gold-tin eutectic crystal having a gold content of about 80% by weight on the outermost surfaces of the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element. A gold-tin layer having a composition is formed in advance and then bonded to the metallized layer of the ceramic substrate.

According to a fifth aspect of the present invention, in the invention of the fourth aspect, the surface of the P-type thermoelectric semiconductor block and the N-type thermoelectric semiconductor block has a gold-tin eutectic composition having a gold content of about 80% by weight. A Pt-type thermoelectric semiconductor element and an N-type thermoelectric semiconductor element having a size suitable for assembling the thermoelectric conversion module are provided. It is characterized in that the gold tin layer on the outermost surface of the type thermoelectric semiconductor element is provided before shredding the P type thermoelectric semiconductor element and the N type thermoelectric semiconductor element.

According to a sixth aspect of the invention, in the invention according to the fifth aspect, the gold tin layer is provided on the outermost surface of each of the P-type thermoelectric semiconductor elements and the N-type thermoelectric semiconductor elements before shredding. When setting up, the content of gold is about 80
A foil or foil having a weight percent gold-tin eutectic composition is heat-sealed to each block, and each block has a size suitable for assembling the thermoelectric conversion module. It is characterized in that it is formed by cutting into small pieces.

According to a seventh aspect of the present invention, in the invention according to the sixth aspect, the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element have a gold plating layer on the outermost surface, and a gold plating layer is formed on the gold plating layer. The foil or foil having a gold-tin eutectic composition having a content of about 80% by weight is heat-sealed.

According to an eighth aspect of the present invention, in the above-mentioned seventh aspect, the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element have the gold plating layer on a nickel layer,
The thickness of the gold plating layer is 0.01 μm or more and 20 μm or less.

According to a ninth aspect of the present invention, in the above-mentioned sixth aspect, the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element have a tin plating layer on the outermost surface, and a tin plating layer is formed on the tin plating layer. The foil or foil having a gold-tin eutectic composition having a content of about 80% by weight is heat-sealed.

According to a tenth aspect of the invention, in the invention of the sixth aspect, the gold-tin foil having the eutectic composition which is heat-sealed to the outermost surfaces of the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element, or The foil has a thickness of 20 μm or more and 60 μm or less.

According to the invention of claim 11, in the invention of claim 5, the gold tin layer is provided on the outermost surface of each of the P-type thermoelectric semiconductor elements and the N-type thermoelectric semiconductor elements before shredding. When setting up, the content of gold is about 8
An alloy layer of 0 wt% gold-tin eutectic composition is electrolytically deposited on the surface of each block, and each block has a size suitable for assembling the thermoelectric conversion module. It is characterized in that it is formed by cutting it into thermoelectric semiconductor elements.

According to a twelfth aspect of the present invention, in the invention according to the fourth aspect, the P-type thermoelectric semiconductor block and the N-type thermoelectric semiconductor block have a size suitable for assembly of the thermoelectric conversion module. After being shredded into the N-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element, the gold-tin layer is provided on the outermost surfaces of the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element.

According to a thirteenth aspect of the present invention, in the invention according to the first aspect, nickel is mainly contained between the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element and the bonding layer having the gold-tin eutectic composition. It is characterized by having a metal layer containing a metal element.

The invention according to claim 14 is the above-mentioned claim 13.
In the invention described above, the P-type thermoelectric semiconductor element and N
Type thermoelectric semiconductor element and the metal layer have an adhesion strength of 50 kg / c
It is characterized by having m2 or more, preferably 80 kg / cm2 or more.

According to a fifteenth aspect of the present invention, in the invention according to the first aspect, a gold-tin layer having the gold-tin eutectic composition is provided on the outermost surface of the metallized layer of the ceramic substrate, and the gold-tin layer is formed. It is characterized in that the metallized layer and each of the thermoelectric semiconductor elements are joined by gold and tin by heating and melting.

According to a sixteenth aspect of the present invention, in the invention according to the first aspect, both the outermost surface of the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element and the outermost surface of the metallized layer of the ceramic substrate are provided. A gold-tin layer having the gold-tin eutectic composition is provided, and both of the gold-tin layers are heated and melted, whereby gold-tin bonding is performed between the metallized layer and each of the thermoelectric semiconductors.

According to a seventeenth aspect of the present invention, in the invention according to the first aspect, the eutectic composition is formed between the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element and the metallized layer of the ceramic substrate. With the gold-tin layer provided, the gold-tin layer is melted by heating at a temperature not lower than the melting point of gold-tin for a time of 10 seconds or more and 5 minutes or less to bond the metallized layer and each thermoelectric semiconductor. It is characterized by

The invention according to claim 18 is the invention according to claim 1, wherein the eutectic composition is formed between the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element and the metallized layer of the ceramic substrate. The metallization layer and each thermoelectric semiconductor element are joined by heating with the gold-tin layer provided, and the metallization of the P-type thermoelectric semiconductor element and N-type thermoelectric semiconductor element and the ceramic substrate after the heating and joining. The thickness of the gold-tin layer remaining at the joint with the layer is 5 μm to 50 μm.

A nineteenth aspect of the present invention is the same as the first aspect of the present invention, wherein the lead wire is attached to the lead member by using a gold-tin eutectic composition bonding agent having a gold content of about 80% by weight. It is characterized in that it is bonded to the metallized layer.

According to a twentieth aspect of the present invention, in the invention according to the first aspect, the metal post is attached to the lead member by using a gold-tin eutectic composition bonding agent having a gold content of about 80% by weight. It is characterized in that it is bonded to the metallized layer.

According to a twenty-first aspect of the present invention, a plurality of P-type thermoelectric semiconductor elements and N-type thermoelectric semiconductor elements, and a pair of ceramic substrates bonded to the upper and lower sides of the P-type thermoelectric semiconductor elements and N-type thermoelectric semiconductor elements, respectively. A metal post for power supply joined to a lead member mounting metallization layer provided on one side of the ceramic substrate as a main component, and the metal post and the lead member mounting metallization layer of the one ceramic substrate. It is characterized by using gold-tin having a eutectic composition of gold and tin containing approximately 80% by weight of gold for the joining with.

The invention according to claim 22 is the above-mentioned claim 21.
In the invention described above, after joining the metal posts to the lead member mounting metallized layers of the pair of ceramic substrates with the gold tin, the thermoelectric semiconductor elements are arranged and joined between the ceramic substrate and the other ceramic substrate. By doing so, the thermoelectric conversion module is assembled.

The invention according to claim 23 is the above-mentioned claim 21.
In the invention described above, after assembling the thermoelectric conversion module by joining the pair of ceramic substrates on the upper and lower sides of each thermoelectric semiconductor element, the metal member and the lead member mounting metallization layer of the one ceramic substrate It is characterized in that it is joined with.

[0048]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

In view of the problems mentioned in the section of the problem to be solved by the present invention, the inventor of the present invention, in particular, presupposes a thermomodule used for precise temperature control of the laser diode of the optical communication module, and the entire optical communication module. The lead-free and laser diode optical axis stabilization studies were conducted, and a method for practical application of a gold-tin eutectic solder with a gold content of 80% by weight and a melting point of 280 ° C. suitable for assembling the thermomodule was established. .

FIG. 1 is a view showing a conceptual side structure of a gold-tin junction Peltier element thermoelectric conversion module (hereinafter abbreviated as gold-tin junction thermomodule) 10 manufactured according to the present invention.

This gold-tin joint thermo-module 10 is
It has a structure in which a plurality of P-type thermoelectric semiconductor elements 13a and N-type thermoelectric semiconductor elements 13b are joined between the ceramic substrate 11 on the heat radiation side and the ceramic substrate 12 on the cooling side.

On one surface (pattern surface) of each of the ceramic substrates 11 and 12, a plurality of independent land portions (metallized layers) 111 and 121 are formed by a printing pattern, for example.

The P-type thermoelectric semiconductor element 13a and the N-type thermoelectric semiconductor element 13b of each pair are arranged on the corresponding land portions 111 on the pattern surface of the ceramic substrate 11.

The pattern surface of the other ceramic substrate 12 is the surface of the P-type thermoelectric semiconductor element 13a and the N-type thermoelectric semiconductor element 13b (land portion 11 of the ceramic substrate 11).
1 so that the P-type thermoelectric semiconductor element 13a and the N-type thermoelectric semiconductor element 13b of each pair are aligned in each land 121 on the pattern surface. Then, the ceramic substrate 11 is arranged so as to face it.

Here, the land portion 1 of the ceramic substrate 11
11 and the land portion 121 of the ceramic substrate 12 are all thermoelectric semiconductor elements 13 in the facing arrangement state described above.
(13a, 13b) are formed in an array pattern that is displaced from each other so as to be connected in series in an electric circuit.

In other words, in the gold-tin joint thermo module 10, a plurality of P-type thermoelectric semiconductor elements 13a and N-type thermoelectric semiconductor elements 13b are vertically and horizontally arranged between the ceramic substrate 11 and the ceramic substrate 12 arranged to face the ceramic substrate 11. They are arranged alternately and are electrically connected in series through the land portions 111 and 121 of the ceramic substrates 11 and 12.

In the gold-tin joint thermomodule 10 of the present invention having such an arrangement form, the P-type thermoelectric semiconductor element 13a and the N-type thermoelectric semiconductor element 13b of each pair are arranged to face each other with these elements 13a and 13b interposed therebetween. Gold tin layers 113 and 123 are provided between the land portion 111 of the ceramic substrate 11 and the land portion 121 of the ceramic substrate 12, respectively.
Are joined by.

In the present invention, the gold tin layers 113 and 123 are used.
As the solder, a gold-tin eutectic composition solder having a gold content of about 80% by weight is used.

At the end of the pattern surface of the ceramic substrate 11, a pair of lead wire mounting land portions 112a-1 and 112a are provided separately from the land portion 111 for mounting the thermoelectric semiconductor element.
-2 (112a-2 does not appear in the figure) is formed.

These lead wire mounting land portions 112a-
1, 112a-2 are connected to a positive electrode and a negative electrode of a power source (not shown), respectively, and are connected to the gold-tin joint thermo module 1
A pair of lead wires 15 for supplying electric power to 0 are joined.

In the present invention, the lead wire mounting land portion 112
A gold-tin eutectic composition solder having a gold content of about 80% by weight is also used for joining the lead wires 15 to the a-1 and 112a-2.

The gold-tin joint thermo module 1
In 0, a metal prism called a post may be used instead of the lead wire 15. In this case, the lead wire mounting land portions 112a-1 and 112a
-2, instead of -2, post mounting land portions 112b-1 and 112
b-2 (see FIGS. 24, 25, and 26) is formed, and the post is joined to the post mounting land portions 112b-1 and 112b-2 by using gold tin solder having the eutectic composition in the above ratio. it can.

With respect to the gold-tin joint thermo-module 10 having such a structure, the N-type thermoelectric semiconductor element 13b is connected to the above power source.
When a direct current is passed from the direction to the P-type thermoelectric semiconductor element 13a, the upper ceramic substrate 12 is cooled and the lower ceramic substrate 11 operates so as to generate heat.

On the back surface (non-pattern surface) side of the pattern surface of the ceramic substrate 11, there is formed a back surface metallization layer 114 for bonding with a heat radiation object, and the back surface (non-pattern surface) of the pattern surface of the ceramic substrate 12 (non-pattern surface). ) Side, the back surface metallization layer 124 for the purpose of bonding with the object to be cooled.
Are formed.

As described above, the gold-tin joint thermo module 10 according to the present invention has the ceramic substrates 11, 12 and P.
Type thermoelectric semiconductor element 13a, N type thermoelectric semiconductor element 13b,
In a thermo module having a power supply lead wire 15 (or a metal post) as a main constituent element, a gold content is included in the bonding between the P-type thermoelectric semiconductor element 13a and the N-type thermoelectric semiconductor element 13b and the ceramic substrates 11 and 12. Is about 80% by weight of gold-tin eutectic composition solder.

Here, the outline of the present invention will be described.

The inventor of the present invention firstly uses a melting point of 28 as a solder for assembling the above-described gold-tin joint thermo-module 10.
When using a gold-tin eutectic solder having a gold content of 80% by weight at 0 ° C., a study was made as to what form the gold-tin should have.

The simplest method is to use gold tin paste on the ceramic substrates 11 and 12 for mounting the P-type thermoelectric semiconductor element 13a and the N-type thermoelectric semiconductor element 13b (land portion 11).
1, 121) is a printing method or a coating method using a dispenser. However, since the outermost surface of the metallized land portions 111 and 121 is usually gold-plated,
Since the molten gold-tin solder flows to the side surfaces of the lands 111 and 121, there is a risk of a short circuit or the like.

In order to avoid this inconvenience, only the surface on which the P-type thermoelectric semiconductor element 13a and the N-type thermoelectric semiconductor element 13b are mounted is plated with gold, and the other side surfaces are made of a metal surface such as copper which is hard to form an alloy with gold. Need to leave. This point can be achieved by switching the method of forming the ceramic substrates 11 and 12 from the subtractive method to the semi-additive method.

Next, a simple method is to use the ceramic substrate 11,
12 and the P-type thermoelectric semiconductor element 13a and the N-type thermoelectric semiconductor element 13b have a gold-finished outermost surface, and gold-tin pellets having a predetermined gold content are sandwiched therebetween and heat-sealed.

This method is applicable to the thermoelectric semiconductor elements 13a and 13a.
Although it is effective for a thermomodule having a relatively large size b, it cannot be said to be the most suitable method for assembling a thermomodule using thermoelectric semiconductor elements 13a and 13b having a minute size of less than 1 mm square.

That is, in order to arrange the gold-tin pellets having a size of less than 1 mm square at a predetermined position without displacement, and to make the thermoelectric semiconductor elements 13a and 13b stand on them and join them, a jig for preventing displacement is developed. Is essential and is not suitable for mass production.

However, if the high viscous flux is used properly, the gold tin pellets can be fixed to the lands 111 and 121 of the ceramic substrates 11 and 12 almost accurately, and the thermoelectric semiconductor elements 13a and 13b are positioned by a predetermined metal plate. It is judged that gold-tin bonding can be achieved by this method if a hole is drilled at the position.

As a more advanced method, there is a method of depositing a gold tin layer (113, 123) of a predetermined composition on the outermost surfaces of the P-type thermoelectric semiconductor element 13a and the N-type thermoelectric semiconductor element 13b.

In the method of forming the gold-tin layer (113, 123) by the plating method, since the precipitation is performed while applying the electric field from the predetermined solution to the surface of the semiconductor element, the variation in the thickness of the precipitation layer in the precipitation surface is made uniform. And that there is no variation in the gold-tin composition with a gold content of 80 weight percent.

Although the process is complicated, the outermost surface of the P-type and N-type thermoelectric semiconductor blocks (corresponding to ingots described later) is finished with gold plating, and then the blocks are subjected to gold tin foil or foil having a predetermined gold content. In advance, and then the block is diced to generate P-type thermoelectric semiconductor element 13a and N-type thermoelectric semiconductor element 13b.
There is a method of arranging a and 13b on the land portions 111 and 121 of the gold-finished ceramic substrates 11 and 12 and heating and fusing.

As described above, this method also has a problem in the positioning accuracy of the thermoelectric semiconductor elements 13a and 13b.
Here too, it is considered feasible if a high-viscosity flux is used for fixing.

With respect to the above-mentioned problems, it was judged that the gold-tin bonding thermomodule 10 could be put into practical use by taking the following measures, and various experiments were conducted to arrive at the present invention.

Further, while the thermo-module 10 is assembled by the gold-tin joint, the lead wire 15 for power supply is used.
Alternatively, the use of tin-antimony-based solder having a low melting point for the joining of metal posts instead of the above leads to a poor lead-free effect, and therefore earnest experiments have been accumulated and a practical lead member joining method has been reached.

Hereinafter, representative examples will be described in detail.

Example 1 (corresponding to claim 2) In this example, first, the P-type thermoelectric semiconductor element 13a and the N-type thermoelectric semiconductor element 13b are subjected to the steps as shown in FIG.
Was generated.

First, ingots (thermoelectric semiconductor blocks) 70 were prepared while heating and pressing P-type and N-type thermoelectric semiconductor powders containing bismuth-tellurium as a main component.

Next, each ingot 70 is sliced and P
A thermoelectric semiconductor wafer 71 of each type was obtained.
The wafer size was about 30 mm x 40 mm, and the thickness was about 0.8 mm depending on the module performance.

The P-type thermoelectric semiconductor wafer 71 and the N-type thermoelectric semiconductor wafer 71 were each etched with a mixed acid of inorganic acids, and electroless nickel plating was applied to the entire circumference of these wafers 71 to a thickness of approximately 4 μm.

Then, gold plating was applied to 0.2 to 0.3 μm.
In this state, the wafer 71 is fixed to a jig, and dicing (shrinking) is performed to remove the P-type thermoelectric semiconductor elements 13a and N.
A thermoelectric semiconductor element 13b was obtained. The element size of the P-type thermoelectric semiconductor element 13a and the N-type thermoelectric semiconductor element 13b after shredding is 0.64 mm × 0.64 mm.

P-type thermoelectric semiconductor device 1 obtained by the above process
Assembly of the thermomodule using 3a and the N-type thermoelectric semiconductor element 13b was performed through a series of steps shown in FIGS.

First, as shown in FIG. 4 (a), the land portion 111 of the ceramic substrate 11 was coated with a gold-tin paste. The gold-tin paste used is a commercial product, which is a gold-tin alloy having a eutectic composition in which the content of gold in the metal component is approximately 80% by weight. The paste contains gold-tin particles with a particle size of 25 to 32 μm and RMA type flux.

The ceramic substrate 11 (same as the ceramic substrate 12 but without the lead wire mounting land portion) is made of alumina having a thickness of 0.3 mm, and one side thereof is P
-Type thermoelectric semiconductor element 13a and N-type thermoelectric semiconductor element 13b
There are 31 land parts 111 that can be arranged one by one.
Only one pattern is formed, and lead wire 1 for power supply
5 for attaching the lead wire mounting land portion 112a-
1, 112a-2 (not shown in FIG. 4 for simplification).

As shown in FIG. 3, the land portion 111 (similarly to the land portion 112 of the ceramic substrate 12) has a copper metallization layer 1111 from the ceramic side, a nickel metallization layer 1112 on it, and a metallization layer 1112 on it. 0.2 gold
.About.0.3 .mu.m plating (gold plating 1113), and the side wall of each land 111 has a bare structure of copper, nickel, and gold.

The back surface of the element mounting surface of the ceramic substrate 11 is metalized 0.1 mm smaller than the outer peripheral portion of the ceramic substrate 11, and copper (copper metallization layer 1141) and nickel (nickel metallization layer 114) are metallized over the entire surface.
2), it has a metallized structure (rear surface metallized layer 114) made of gold (gold plated 1143).

In the step of applying the gold-tin paste shown in FIG. 4A, a metal mask having a hole is placed on the pattern surface of the ceramic substrate 11 at the same position as the pattern (land 111), Squeeze the gold tin paste from above.

Excessive gold-tin paste was removed with a metal spatula to obtain a uniform thickness, and about 50 μm of gold-tin paste was applied.

After removing the metal mask, a carbon jig having a thickness of about 1 mm with holes was placed on the positions where the thermoelectric semiconductor elements 13a and 13b were arranged, and the gold-plated thermoelectric semiconductor element produced by the method shown in FIG. 13a and 13b are arranged [see FIG. 4 (b)].

In this state, a weight for preventing displacement was placed, placed in a vacuum furnace, heated to 320 ° C. at a temperature rising rate of 10 ° C./minute, and held for 1 minute to perform gold-tin bonding [ See FIG. 4 (c)].

The π set state module in which only the ceramic substrate 11 and one of the thermoelectric semiconductor elements 13a and 13b obtained were joined, and the joining state was good without the outflow of gold tin.

Next, as shown in FIG. 5A, the gold tin paste is applied to the land portion 121 of the other ceramic substrate 12 in the same manner, and the gold of the π-set state module prepared above is applied. It was overlapped with the surface element (thermoelectric semiconductor elements 13a, 13b) side.

Then, the heating step shown in FIG. 5B is carried out. Here, instead of the carbon jig, the whole (the whole module in the assembled state) is sandwiched by metal plates, and a vacuum furnace is used. Heated. The heating conditions are π described above.
It was the same as when the assembly state module was generated [see FIG. 4 (c)].

The gold-tin joint thermo-module 10 obtained through the above steps has an internal resistance (R
1), and then -40 ℃ / 85 ℃ (30 minutes / cycle, 20
Cycle) thermal shock test and reversal energization test (current was applied so that the temperature difference between the cooling side and the heat radiating side reached 70 to 75 ° C, switching for 7.5 seconds, 72 cycles).

As a result of measuring the internal resistance (R2) after the test and obtaining the resistance change rate, it was confirmed that all the thermomodules had an internal resistance change rate of about 0.5% and functioned sufficiently as a thermomodule.

Therefore, it was confirmed that the assembly of the thermomodule 10 using the gold-tin paste was effective.

Example 2 (corresponding to claim 3) Also in this example, the P-type thermoelectric semiconductor element 13a and the N-type thermoelectric semiconductor element 13b are processed through the steps shown in FIG.
Was generated.

First, P containing bismuth-tellurium as a main component
The respective ingots 70 were produced while heating and pressing the mold and N-type thermoelectric semiconductor powder. Each of these ingots 7
0 was sliced to obtain a P-type thermoelectric semiconductor wafer 71 and an N-type thermoelectric semiconductor wafer 71. Wafer size is about 30
mm × 40 mm with a thickness of approximately 0.8 mm was prepared depending on the module performance.

This wafer 71 was subjected to gold plating in the same manner as in Example 1 (see FIG. 2) to finish the P-type thermoelectric semiconductor element 1 with gold.
3a and N-type thermoelectric semiconductor element 13b were attached to a fixing jig and diced to a size of 0.64 mm × 0.64 mm.

The ceramic substrate 11 (the same applies to the ceramic plate 12) used for assembling the thermo module in this embodiment.
However, the thickness of the lead wire mounting land is not 0.3)
Made of m alumina, one side of which is a P-type thermoelectric semiconductor element 13
a and N-type thermoelectric semiconductor element 13b are provided with 31 land portions 111 each capable of being arranged one by one, and lead wire attaching land portions 112a-1, 112a- for attaching lead wires 15 for power supply. 2 is formed.

Land portion 111 on the ceramic substrate 11
(The land 112 of the ceramic substrate 12 is also the same.) The structure is as follows: from the ceramic side, a copper metallization layer, a nickel metallization layer on it, and gold 0.2 to 0.3 μm on it.
It is a plated structure, the side wall of each land 111 is copper,
The structure is bare nickel and gold (see Fig. 3).

The surface opposite to the pattern surface of the ceramic substrates 11 and 12 is 0.1 mm from the outer periphery of the ceramic substrates 11 and 12.
The metallization is small and has a metallized structure made of copper, nickel and gold over the entire surface (Fig. 3).
reference).

In this embodiment, using the P-type thermoelectric semiconductor element 13a, the N-type thermoelectric semiconductor element 13b, and the ceramic substrates 11 and 12 described above, a series of steps shown in FIGS. Ten assemblies were made.

First, as shown in FIG. 6A, a highly viscous flux was applied to the pattern (land portion 111) of the ceramic substrate 11.

After that, a carbon mask having a hole at the same position as the land portion 111 is covered, and a gold tin foil (thickness: 0.7 mm square) punched into the same size as the thermoelectric semiconductor elements 13a, 13b. 35 μm) was attached [Fig. 6
(B)].

Then, as shown in FIG. 6C, after the thermoelectric semiconductor elements 13a and 13b having a gold plating finish are arranged on the gold tin foil by using a jig made of carbon, as shown in FIG.
As shown in (d), a weight for preventing misalignment was placed and the mixture was heated and melted in a vacuum furnace.

The heating conditions were heating to 320 ° C. at a temperature rising rate of 10 ° C./min and holding for 1 minute to perform gold-tin bonding. The π set state module in which only one of the obtained ceramic substrate 11 and the thermoelectric semiconductor elements 13a and 13b was joined did not flow out of gold and tin, and the joined state was good.

Next, the carbon jig was removed, and as shown in FIG. 7 (a), a gold tin foil was attached to the gold-plated finished surfaces of the thermoelectric semiconductor elements 13a and 13b which were not joined, by using a highly viscous flux. Then, after stacking another ceramic substrate 12, as shown in FIG. 7B, the ceramic substrate 12 was fixed to a metal jig for preventing misalignment and heated and melted in a vacuum furnace.

The heating conditions were the same as those used when the π-group state module was generated as described above (see FIG. 6D).

A thermocouple was bonded to one surface of the gold-tin-bonded thermomodule 10 thus prepared with lead-tin solder, and the other surface was set on a water-cooled plate whose temperature was controlled. It was confirmed that there was a temperature difference of about 70 ° C. between the cooling side substrate 11 and the heat radiation side substrate 12 when the maximum current (about 1.2 A) was applied to the module 10. Therefore, it was confirmed that the thermomodule 10 using gold-tin pellets (foil) can be sufficiently assembled.

Example 3 (corresponding to claims 4 to 6) In this example, a P-type thermoelectric semiconductor element 13a and an N-type thermoelectric semiconductor element 13b were produced through the steps as shown in FIG. .

First, ingots 70 (see FIG. 2) were prepared while heating and pressing P-type and N-type thermoelectric semiconductor powders containing bismuth-tellurium as a main component. Each ingot 70 was sliced to obtain a P-type thermoelectric semiconductor wafer 71 and an N-type thermoelectric semiconductor wafer 71. The wafer size was about 30 mm x 40 mm, and the thickness was about 0.8 mm depending on the module performance.

To secure the adhesion, the P-type thermoelectric semiconductor wafer 71 and the N-type thermoelectric semiconductor wafer 71 were each etched with a mixed acid of inorganic acid, and then electroless nickel plating was applied to the entire circumference of the wafer to a thickness of about 4 μm. Then, gold plating was applied to 0.2 to 0.3 μm.

Next, the gold plated wafer
A 35 μm-thick gold tin foil (foil) was heat-sealed in a reducing atmosphere (high-purity nitrogen gas added with a trace amount of hydrogen gas). The size of the gold-tin foil used was 15 mm × 40 mm, and two of them were arranged on one side of the wafer 71 and fused. The heating conditions were such that the temperature was raised to 320 ° C. at a temperature rising rate of 10 ° C./minute and the temperature was maintained for 1 minute. The cooling rate was 10 ° C./minute, and the temperature was cooled to room temperature.

Then, the obtained gold-tin fused wafer 71 is obtained.
Was fixed to a jig and diced into a size of 0.64 mm × 0.64 mm to obtain a P-type thermoelectric semiconductor element 13a and an N-type thermoelectric semiconductor element 13b.

The ceramic substrate 11 used for assembling the thermomodule of this embodiment (same as the ceramic plate 12, but without the lead wire mounting land portion) has a thickness of 0.3 mm.
Made of alumina, one side of which is a P-type thermoelectric semiconductor element 13a
And only 31 pairs of land portions 111 are formed so that one N-type thermoelectric semiconductor element 13b can be arranged, and lead wire attachment land portions 112a-1 and 112a-2 for attaching lead wires for power supply are formed. A pattern is formed.

The structure of the land portion 111 of the ceramic substrate 11 (similarly to the land portion 121 of the ceramic substrate 12) is as follows.
Copper metallization layer, nickel metallization layer on it,
Furthermore, gold has a structure of 0.2 to 0.3 μm plated thereon, and the side walls of each pattern (lands 111 and 121) are exposed with copper, nickel and gold (see FIG. 3).

Further, the surface opposite to the pattern surface (element mounting surface) of the ceramic substrate 11 has a metallized structure made of copper, nickel and gold over the entire surface of the ceramic substrate 11 so as to be 0.1 mm smaller than the outer peripheral portion (see FIG. 3).

In this embodiment, using the P-type thermoelectric semiconductor element 13a and the N-type thermoelectric semiconductor element 13b and the ceramic substrates 11 and 12 described above, a series of steps shown in FIGS. Assembling 10 was done in air.

Specifically, a highly viscous flux is applied to the land portion 111 on the pattern surface of the ceramic substrate 11 (see FIG. 9A), and then gold tin is fused on the P type thermoelectric semiconductor. Element 13a, N-type thermoelectric semiconductor element 13
b were arranged [see FIG. 9 (b)], and gold-tin bonding was performed at a heating part set temperature of 390 ° C. for 20 seconds [see FIG. 9 (c)].

Ceramic substrate 1 obtained through the above steps
1 and one of the thermoelectric semiconductor elements 13a and 13b are joined together, the π set state module is a gold-tin ceramic substrate 1
Wetting to No. 1 was also good, and the bonding state was good.

Next, another ceramic substrate 12 is overlaid on the above-mentioned π set state module [FIG. 10].
(See (a)), and further heated at 345 ° C. for 3 minutes together with the fixing jig (see FIG. 10 (b)) to obtain a gold-tin jointed thermo module 10.

The thermo module 10 thus obtained measures the internal resistance (R1) after the lead wire 15 is attached, and then measures -40
℃ / 85 ℃ (30 minutes / cycle, 20 cycles) thermal shock test and reversal energization test (current is applied so that the temperature difference between the cooling side and the heat radiating side becomes 70 to 75 ℃, 7.5 seconds switching, 7
2 cycles).

The internal resistance (R2) after the test was measured, and the rate of resistance change was calculated.
It was confirmed that the increase was about a percentage and that the thermomodule 10 sufficiently functions.

From the above, the P-type thermoelectric semiconductor element 13
a and about 8 on the outermost surface of the N-type thermoelectric semiconductor element 13b.
It was confirmed that it is sufficiently possible to provide a gold-tin layer having a eutectic composition containing 0% by weight of gold and assemble the thermomodule 10 using this as a bonding agent.

Example 4 (corresponding to claims 7 and 8) In this example, a P-type thermoelectric semiconductor element 13a and an N-type thermoelectric semiconductor element 13b were produced through the steps shown in FIG.

First, while heating and pressurizing P-type and N-type thermoelectric semiconductor powders containing bismuth-tellurium as a main component, respective ingots 70 (see FIG. 2) were prepared, and each ingot 70 was sliced to obtain P. A type thermoelectric semiconductor wafer 71 and an N-type thermoelectric semiconductor wafer 71 were obtained. The wafer size was approximately 30 mm x 40 mm, and the thickness was approximately 0.8 mm due to module performance.

The P-type thermoelectric semiconductor wafer 71 and the N-type thermoelectric semiconductor wafer 71 were each etched with a mixed acid of inorganic acids, and then electroless nickel plating was applied to the entire circumference of the wafer to 4 μm.

After that, gold plating is applied for flash gold (0.01 μm in fluorescent X-ray film thickness measurement), 0.2 to 0.3 μm, 5 μm, 10 μm.
A gold-plated wafer having a level of m and 20 μm (observation of resin-embedded cross section after dicing) was manufactured as a prototype. For comparison, a level (not shown) stopped by nickel plating was also prototyped.

Next, a gold tin foil (foil) having a thickness of 35 μm was placed on both surfaces of each gold-plated wafer and a nickel-plated wafer, and they were fused by using a vacuum furnace. As in the case of Example 3, the fusing conditions are holding at 320 ° C. for 1 minute in a reducing atmosphere.

In such a process, gold tin tended to spread wider than the original area on the gold-plated wafer, but no spread was seen on the nickel-plated wafer, and nickel and gold tin were not spread at all. Foil bonding was also inadequate.

Then, each wafer was diced into a square of 0.64 mm × 0.64 mm to obtain a P-type thermoelectric semiconductor element 13a and an N-type thermoelectric semiconductor element 13b. In this process, the gold-plated wafer had no problem, but the nickel-plated wafer could not be used for module assembly because the gold-tin layer partially peeled during dicing.

The thermomodule in this example was assembled using an alumina substrate having 23 pairs of lands. Specifically, using an automatic assembly machine, a highly viscous flux is applied to an alumina substrate, and the P-type thermoelectric semiconductor element 13a and the N-type thermoelectric semiconductor element 13b for each gold plating level are arranged on the alumina substrate at 375 ° C. It was made a π set state module under the heating condition of second.

Then, another ceramic substrate was placed on the substrate of the π set state module and heated while being sandwiched by the jigs for both sets to obtain a gold-tin bonded thermomodule 10 consisting of 23 pairs of thermoelectric semiconductor element pairs. .

After the assembly is completed, the lead wire is attached, the internal resistance (R1) is measured, and then the thermal shock test of -40 ° C / 85 ° C (30 minutes / cycle, 20 cycles) and the reversal energization test (cooling side / Current was applied so that the temperature reached on the heat dissipation side was 70 to 75 ° C, switching was performed for 7.5 seconds, and 72 cycles were performed.

The internal resistance (R2) after the test was measured, and the rate of change in resistance was determined. As a result, it was confirmed that all the thermomodules had an increase of about 0.5% and that they functioned sufficiently as thermomodules.

Thereafter, tin-silver-copper solder (melting point 217 ° C.) was used to join copper-tungsten (20%) plates having a thickness of 1 mm to both sides of the thermomodule. As a result of evaluating the durability of the sample thus produced by the thermal shock test, the change in resistance value after 1000 cycles was different depending on the thickness of the gold plating.

The largest change in resistance was 0.01μ.
At the gold plating level of m, the other gold plating levels were almost at the same level. The 0.01 μm gold plating level reached an internal resistance change of 5% after about 100 cycles, while the other levels had an internal resistance change of less than 2% after 1000 cycles.

Therefore, when the gold tin foil is fusion-bonded to the thermoelectric semiconductor wafer, it is necessary to perform gold plating on the outermost surface of the wafer, preferably 0.01 μm or more.

Example 5 (corresponding to claim 9) In this example, a P-type thermoelectric semiconductor element 13a and an N-type thermoelectric semiconductor element 13b were produced through the steps shown in FIG.

First, each ingot 70 (see FIG. 2) is prepared while heating and pressing P-type and N-type thermoelectric semiconductor powders containing bismuth-tellurium as a main component, and each ingot 70 is sliced to obtain P. A type thermoelectric semiconductor wafer 71 and an N-type thermoelectric semiconductor wafer 71 were obtained. The wafer size was about 30 mm x 40 mm, and the thickness was about 0.8 mm depending on the module performance.

The P-type thermoelectric semiconductor wafer 71 and the N-type thermoelectric semiconductor wafer 71 were each etched with a mixed acid of inorganic acids, and then electroless nickel plating was applied to the entire circumference of the wafer to a thickness of approximately 4 μm.

Thereafter, a tin plating layer of 1 μm or 2 μm was formed on the outermost surface of the wafer 71 as a prototype, and a nickel plated layer was prepared for comparison as a prototype.

35 μm on both sides of each of these surface-treated wafers
Thick gold-tin foil sandwiched in a vacuum furnace in a reducing atmosphere at 320 ° C
A fusion with a gold tin foil (foil) was tried under heating conditions of × 1 minute holding.

0.64 mm × 0. By dicing each wafer.
The wafer was shredded into 64 mm square pieces, but the gold-tin foil was fused to the nickel-plated finish, and partial peeling of the gold-tin layer was observed during dicing. The tin-plated wafer was firmly adhered to the thermoelectric semiconductor and no peeling was observed.

The tin-plated finish thermoelectric semiconductor elements 13a and 13b, which were found to be possible to assemble by the above observation, were assembled in the same manner as in Example 4 to assemble the gold-tin joint thermomodule 10. As a result, the melting point of gold-tin did not change significantly, and the adhesion between the element and the substrate was good even in the destructive test after module assembly.

Gold-tin bonded thermo module 10 after assembly
After attaching the lead wire to the lead wire, the rate of change in resistance before and after the thermal shock test and reverse current test was 0.3 to 0.6% for both gold-plated and tin-plated finishes, the same as when using normal lead-based solder. It was a level.

Example 6 (corresponding to claim 10) In this example, a P-type thermoelectric semiconductor element 13a and an N-type thermoelectric semiconductor element 13b were produced through the steps shown in FIG.

First of all, P-type and N-type thermoelectric semiconductor powders containing bismuth-tellurium as a main component are heated and pressed to make respective ingots 70 (see FIG. 2), and each ingot 70 is sliced to obtain P. A type thermoelectric semiconductor wafer 71 and an N-type thermoelectric semiconductor wafer 71 were obtained. The wafer size was approximately 30 mm x 40 mm, and the thickness was approximately 0.8 mm due to module performance.

The P-type thermoelectric semiconductor wafer 71 and the N-type thermoelectric semiconductor wafer 71 were each etched with a mixed acid of an inorganic acid, and then electroless nickel plating was applied to the entire circumference of the wafer to 4 μm. After that, further gold plating 0.2-0.3 μm
Attached and prototyped a gold-plated finished wafer.

Both sides of this gold-plated finished wafer were fused with a gold tin foil (foil) having a predetermined thickness using a vacuum furnace. The thickness of the prepared gold-tin foil is 20μm, 35μm, 50μm, 6
After fusion bonding at 4 levels of 0 μm, dicing was performed into a 0.64 mm × 0.64 mm square, and a gold-tin bonding thermomodule 10 was prepared using an alumina substrate having 23 pairs of lands.

Then, after conducting a thermal shock test and a reverse current test, a copper-tungsten (20%) plate having a thickness of 1 mm was joined to both sides of the thermomodule using tin-silver-copper solder.

The durability of the sample thus produced was evaluated by the thermal shock test.
The change in resistance value after the completion of the cycle depended on the thickness of the gold-tin foil used for fusion bonding.

As a result, it was observed that the rate of change in internal resistance tended to be smaller when thin gold tin was used than when thick gold tin foil was used. Also, when using a 60 μm gold tin foil, excess gold tin accumulates between the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element when the thermo module is assembled, and when a thicker gold tin foil is used, a short circuit occurs during assembly. It became clear that there is a possibility.

Therefore, it was judged that good results can be obtained by fusing a gold tin foil of 20 μm to 60 μm as a practical range.

Example 7 (corresponding to claim 11) In this example, a P-type thermoelectric semiconductor element 13a and an N-type thermoelectric semiconductor element 13b were produced through the steps shown in FIG.

First, ingots 70 (see FIG. 2) were prepared while heating and pressing P-type and N-type thermoelectric semiconductor powders containing bismuth-tellurium as a main component. Each ingot 70 was sliced to obtain a P-type thermoelectric semiconductor wafer 71 and an N-type thermoelectric semiconductor wafer 71. The wafer size was about 30 mm x 40 mm, and the thickness was about 0.8 mm depending on the module performance.

The P-type thermoelectric semiconductor wafer 71 and the N-type thermoelectric semiconductor wafer 71 were each etched with a mixed acid of inorganic acids, and then electroless nickel plating was applied to the entire circumference of the wafer 71 to a thickness of approximately 4 μm.

Then, using a commercially available gold-tin plating solution,
An alloy layer of gold-tin was deposited on nickel. As a preliminary test, the gold-tin layer was deposited so as to have a thickness of 5 μm, and the film thickness and composition were analyzed by fluorescent X-ray.

When the thickness was about 5 μm, the thickness of the deposited gold-tin layer was almost uniform, but the composition was such that the aim of the gold / tin ratio was 80/20 to that of gold-rich 90/10. It was

After that, the composition of the electrolytic solution was changed to deposit a gold / tin composition having a composition of 80/20, which was almost aimed, and a trial was performed with a thickness of 35 μm. When the thickness of the deposited gold-tin layer is about 35 μm, the center of the wafer is around 35 μm, while the outer periphery of the wafer is 60 μm.
It became about the thickness.

A wafer (see FIG. 14) having an outermost surface coated with a gold-tin layer by electroforming was diced into a size of 0.64 mm × 0.64 mm, and the P-type thermoelectric semiconductor element 13 thus obtained was obtained.
The gold-tin joint thermomodule 10 was assembled using a and N-type thermoelectric semiconductor elements.

The ceramic substrate 11 used for the assembly in this embodiment is made of alumina having a thickness of 0.3 mm, and the P-type thermoelectric semiconductor element 13a and the N-type thermoelectric semiconductor element 13b are provided on one surface thereof.
18 land parts that can be mounted one by one
Pairs are formed (18 pairs of lands 121 are formed on the other ceramic substrate 12), and lead wire mounting lands 112a for mounting the leads 15 for power supply are further formed.
-1,112a-2 are formed as a pattern.

The structure of the land portion 111 (similarly to the land portion 121 on the other substrate 12) is such that the metallization layer of copper is formed from the ceramic substrate side, the metallization layer of nickel is formed on the metallization layer, and gold is formed on the metallization layer in the range of 0.25 to 0.25. It is plated with 0.35 μm (see Figure 3).

The surfaces opposite to the pattern surfaces (element mounting surfaces) of the ceramic substrates 11 and 12 are the ceramic substrates 11 and 12.
It has a metallized structure consisting of copper, nickel, and gold over the entire surface, which is 0.1 mm smaller than the outer periphery (see FIG. 3).

The thermomodule in this example was assembled in air using an automatic machine. Specifically, a high-viscosity flux is applied to the land portion 111 on the pattern side of the ceramic substrate 11, and gold-tin is fused on the land portion 111 using the deposition method shown in FIG. Type thermoelectric semiconductor elements 13b are arranged, and the heating part set temperature is 4
Bonding was performed at 00 ° C. for 20 seconds.

The π set state module in which only one end face of the thermoelectric semiconductor elements 13a and 13b was joined to the ceramic substrate 11 obtained in the above process had uneven wettability due to each land portion 111. It is presumed that this is because the thickness of the gold-tin layer deposited on the thermoelectric semiconductor elements 13a and 13b described above varies.

Next, another ceramic substrate 12 and π
Superimpose the assembly status module on both assembly status,
It was heated at 360 ° C. for 3 minutes together with the fixing jig to obtain a gold-tin joint thermo module 10.

Lead wires were attached to the obtained thermo-module 10, and the resistance change rate of the thermo-module 10 before and after the thermal shock test and the reverse current test was 0.7% at maximum, and it was confirmed that the thermo-module 10 functions. .

After that, the thermomodule 10 was embedded in an epoxy resin and polished to confirm the bonding state. FIG. 15 is a side view of the joined state.

For comparison, FIG. 16 shows the observation result of the bonding state of the thermomodule 10 prepared in Example 2 under the same conditions (epoxy resin embedding and polishing).

Embodiment 8 (corresponding to claim 12) In this embodiment, after the P-type thermoelectric semiconductor element 13a and the N-type thermoelectric semiconductor element 13b are produced through the steps as shown in FIG. A gold tin layer is formed on the outermost surfaces of the semiconductor elements 13a and 13b.

First, ingots 70 were prepared while heating and pressing P-type and N-type thermoelectric semiconductor powders containing bismuth-tellurium as a main component. Each ingot 7
0 was sliced to obtain a P-type thermoelectric semiconductor wafer 71 and an N-type thermoelectric semiconductor wafer 71. Wafer size is roughly
30mm x 40mm, thickness is about 0.8mm depending on module performance
I prepared one.

After that, these wafers 71 are etched, then electroless nickel plating (4 μm) is applied over the entire circumference of the wafer, and gold plating is applied to 0.2 to 0.3 μm.

The gold-plated P-type thermoelectric semiconductor wafer 71 and the N-type thermoelectric semiconductor wafer 71 were attached to a fixing jig, and by dicing into 0.64 mm × 0.64 mm square, the P-type thermoelectric semiconductor element 13a and the N-type thermoelectric semiconductor were formed. Element 13b was obtained (see FIG. 2 above).

Further, the gold tin foil was fused to the outermost surfaces of the P-type thermoelectric semiconductor element 13a and the N-type thermoelectric semiconductor element 13b by using a jig made of carbon.

The carbon jig is, for example, as shown in FIG.
As shown in FIG. 5, a carbon plate 171 having a thickness of about 5 mm is provided with a large number of reamed holes 172 having a depth of 1 mm and φ1.

As shown in FIG. 17B, 35 μm gold-tin foil punched into 0.7 mm square was put in each of these jigs 170 one by one, and the thermoelectric semiconductor element 13 having a gold plating finish was placed thereon.
The a and 13b were erected. Then, the thermoelectric semiconductor element 13
Gold tin foil of the same size was placed on the gold-plated surfaces on the upper surfaces of a and 13b, and heat fusion was performed in a reducing atmosphere as shown in FIG. 17 (c). The fusing condition is a reducing atmosphere 320.
It was carried out at a temperature of 1 ° C. for 1 minute.

In this way, the thermoelectric semiconductor elements 13a, 13
When the gold tin foil is fused in the element state after being shredded as b, the amount of gold tin per element can be strictly controlled, but the gold tin layer formed on the element is as shown in FIG.
As shown in, the surface was close to a spherical surface as if the bowl had been turned down by surface tension.

However, since this shape does not cause a problem in assembling, the thermoelectric semiconductor elements 13a and 13b and the pair of ceramic substrates 11 having 31 pairs of lands are formed by the same method as that described in the third embodiment. , 12 were used to assemble the gold-tin joint thermomodule 10.

When the thermomodule 10 after assembly was broken and the bonding state of gold and tin was inspected, the amount of gold and tin was controlled, so that the spread of gold and tin between the patterns (lands) was uniform. The result was obtained.

After attaching the lead wire 15 to the thermo module 10 assembled by the above method, the internal resistance is
(R1) is measured, and then -40 ℃ / 85 ℃ (30 minutes / cycle,
20 cycles) thermal shock test and reverse current test
(Current was applied so that the temperature reached on the cooling side / heat radiating side was 70 to 75 ° C., switching was performed for 7.5 seconds, and 72 cycles).

The internal resistance (R2) after this test was measured and the rate of resistance change was calculated.
This is a rise of about 0.5%, and Thermo Module 1
It was confirmed that the value of 0 was sufficient.

From the above, the P-type thermoelectric semiconductor element 13
It was confirmed that the a and N-type thermoelectric semiconductor elements 13b were shredded, a gold-tin layer was provided on the outermost surface thereof, and the gold-tin bonded thermomodule 10 was assembled using these elements 13a and 13b.

Example 9 (Corresponding to Claim 13) In this example, the P-type thermoelectric semiconductor element 13a and the N-type thermoelectric semiconductor element 13b having different nickel plating layers through the steps as shown in FIG. After producing, a module was assembled using these elements 13a and 13b, and a thermal test was tried.

First, P-type and N-type thermoelectric semiconductor powders containing bismuth-tellurium as a main component are heated and pressed to make respective ingots 70 (see FIG. 2), and each ingot 70 is sliced to obtain P. A type thermoelectric semiconductor wafer 71 and an N-type thermoelectric semiconductor wafer 71 were obtained. The wafer size was about 30 mm x 40 mm, and the thickness was about 0.8 mm depending on the module performance.

Next, the P-type thermoelectric semiconductor wafer 71 and the N-type thermoelectric semiconductor wafer 71 were each etched with a mixed acid of inorganic acids, and then nickel-plated.

Here, the standard electroless nickel plating level and the electrolytic nickel plating level used for decoration were deposited to a level of about 4 μm. Gold plating was applied on the nickel plating to 0.2 to 0.3 μm to prepare a gold-plated finished wafer.

Next, both sides of each gold-plated wafer are 35 μm thick.
After fusing with a thick gold tin foil (foil) using a vacuum furnace, dicing into a 0.64 mm × 0.64 mm square,
-Type thermoelectric semiconductor element 13a and N-type thermoelectric semiconductor element 13
b was obtained, and these elements 13a and 13b were used to assemble a gold-tin bonded thermomodule 10 having 23 pairs of elements.

Then, after performing a thermal shock test and a reversal energization test on this thermomodule, a copper-tungsten (20%) plate having a thickness of 1 mm was joined to both sides of the thermomodule 10 using tin-silver-copper solder. .

Reverse electrification of the sample module thus prepared (current is applied so that the temperature of the heat radiation side substrate and the temperature of the cooling side substrate may fluctuate between 25 ° C. and 85 ° C.)
As a result of evaluating the durability by, the change in resistance value after 40,000 cycles was less than 5% of the pass / fail judgment regardless of the type of nickel plating.

For comparison, in this example, the wafer 7 was used.
Immediately after etching No. 1, a sample with 0.2 to 0.3 μm of gold plating was made as a prototype.

As with other nickel-plated wafers, 35 μm-thick gold-tin foil was fused on both sides of this sample and diced to form thermoelectric semiconductor elements 13a, 1.
3b, and then using these elements 13a and 13b,
A sample module with a pair of elements was created.

The durability of this sample module was evaluated after bonding the copper-tungsten plates to each other in the same manner as the other modules 10. However, all the sample modules had a very short cycle number and the resistance change amount was 5%. Exceeded. It is presumed that the peeling occurred at the interface between the Bi-Te base material and the gold-tin layer, and the resistance value increased due to this.

Example 10 (corresponding to claim 14) In this example, a P-type thermoelectric semiconductor wafer 71 and an N-type P-type thermoelectric semiconductor wafer 71 on which gold-tin foil was heat-sealed by the same method as in Example 3 (see FIG. 8) were used. A thermoelectric semiconductor wafer 71 was prepared.

However, in this example, the gold-tin fused wafer 7 was changed by changing the etching treatment chemicals of the underlayer and the treatment time.
Created 1. As a result, depending on the etching conditions, crater-like wrinkles as shown in FIG. 19 were generated on the surface of the gold-tin wafer.

When the gold-tin fused wafer 71 having such crater-like wrinkles was diced, peeling frequently occurred at the interface between the bismuth-tellurium base material and the nickel at the wrinkle-occurring portion, so that local peeling occurred. It is inferred that the adhesion strength of the base metal / nickel interface is weakened.

In order to quantitatively grasp the magnitude of this adhesion, a nickel / gold plated wafer under the same etching conditions was diced into 3 mm squares, one side of which was soldered to a 2 mm thick copper plate with tin antimony solder, and vice versa. The surface was soldered with tin-plated copper nails using lead-tin solder.

Using the sample thus prepared, 20
It was pulled vertically at a constant speed of mm / min, and the breaking strength was evaluated as the adhesion. As a result, it became clear that the above-mentioned crater-like wrinkles occur when the adhesive force per square centimeter is less than 50 kg. On the contrary, it was found that an adhesion force of 50 kg or more per square centimeter was required to prevent wrinkles on the craters.

Further, in this example, based on the above experimental results, for example, in accordance with the procedure shown in FIG. 20, from the P-type and N-type thermoelectric semiconductor wafer 71, a sample having an adhesion force F of about 40 kg per square meter, about 50 kg. Sample, approximately 80 kg sample, approximately 100 kg sample are prepared, each sample (wafer) is heat-sealed with gold-tin foil, and further diced into thermoelectric semiconductor elements 13a and 13b.
A gold-tin bonding thermomodule 10 was prepared using a and 13b.

[0205] As described above, the sample having an adhesion force of less than 50 kg per square meter had crater-like wrinkles, and peeling frequently occurred during dicing, but those without peeling were selected and provided for assembly.

Each of the thermomodules assembled by using the above-mentioned four levels of samples was subjected to a thermal shock test (100 cycles) of applying −40 ° C. and 85 ° C. at 15 minute intervals, and as a result, the internal resistance values before and after the test were measured. The amount of change is adhesion of 80
The thermo-module with an adhesive force of 40 kg was obviously larger than the thermo-module with more than kg.

Here, when a product having a change rate of 2% is judged as a defective product, there is a clear correlation between the defective ratio and the adhesive force, and a thermomodule having an adhesive force of 80 kg or more per 1 cm 2 is defective. Rate is 0% (0/50)
On the other hand, in the thermo module with the adhesion of 40 kg,
The defective rate was 18% (9/50). Also 50k
The thermo-module having an adhesion force of g had a defective rate of 4 (2 pieces / 50 pieces).

From the above, it is practically necessary that the gold-tin joint thermo-module 10 has an adhesion force between the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor and the nickel interface of 50 kg or more per square centimeter, preferably 80 kg or more. I was able to confirm that.

Example 11 (corresponding to claim 14) The same test as in Example 10 was conducted for the gold-tin paste method. Specifically, the etching conditions were changed in the same manner as in Example 10 to prepare a nickel / gold-plated wafer having different adhesion between the bismuth-tellurium base material and the nickel interface, and gold tin was prepared in the same manner as in Example 1. The junction thermo module 10 was created.

Thereafter, the thermal shock test described in Example 10 was carried out to examine the relationship between the adhesive force and the defective rate. In this case as well, similar to Example 10, if the adhesive force is less than 50 kg, the defective rate is high. It became clear that it was not practical.

Embodiment 12 (corresponding to claim 15) In this embodiment, the land portions (metallized layers) 111, 12 of the ceramic substrates 11, 12 are manufactured by the procedure shown in FIG.
The gold-tin layer was formed on No. 1 and the gold-tin bonded thermomodule 10 was assembled using the thermoelectric semiconductor elements 13a and 13b having only gold plating finish.

In this embodiment, the gold-tin layer is formed on the metallized surface of the substrate by forming a predetermined amount of commercially available gold-tin paste on the metallized surface (land portion 1) of the ceramic substrates 11 and 12.
11, 121) [see FIG. 21 (a)], and then heated in a vacuum furnace at 320 ° C. for 1 minute in a reducing atmosphere [see FIG. 21 (b)].

The ceramic substrates 11 and 12 used are alumina-made 23-pair land portion holding substrates made by the semi-additive method, and the outer dimensions are approximately 6 mm × 8 mm.

The thickness of the gold-tin layer in one coating / heating treatment was about 10 μm from the cross-section observation [see FIG. 21 (b)].

This process is repeated twice more to obtain
A 30 μm gold-tin layer was formed on the land [Fig. 21 (c)]
reference〕. Since the substrates 11 and 12 were formed by the semi-additive method, most of the sidewalls of the lands 111 and 121 had bare copper, and gold tin did not flow into the sidewalls during melting.

[0216] The ceramic substrate 1 thus obtained
1, 12 and a thermoelectric semiconductor element 13 finished with gold plating
The gold-tin bonded thermomodule 10 was assembled using a and 13b (for example, those produced by the method of FIG. 2) [see FIG. 21 (d)].

As for the assembling method, the substrate 11 is placed at a predetermined position by using an automatic machine, and the thermoelectric semiconductor elements 13a and 13b are applied while applying the highly viscous flux to the land 111 of the substrate 11.
It was done by the method of placing.

After the thermoelectric semiconductor elements 13a and 13b are arranged,
Immediately, they were heat-bonded at 350 ° C. for 12 seconds to obtain a π set state module. After that, another substrate 12 is placed on the π-set state module and heated at 350 ° C. for 2 minutes, so that the thermoelectric semiconductor elements 13a and 13b and the substrate 1 are heated.
A gold-tin bonding thermomodule 10 in which the 1st and 12th parts were joined by the gold-tin layers 113 and 123 was produced.

In both of these assembled states, the joining state was confirmed by embedding it in an epoxy resin and polishing, and the re-melted gold-tin was almost the same as the joining states of the modules prepared in other examples, showing a good joining state. Was present.

After that, the lead wire 15 is attached to the thermo module 10, the internal resistance (R1) is measured, and the temperature is -40 ° C / 85 ° C (30 ° C).
Min / cycle, 20 cycles) thermal shock test and reverse electrification test (achievement temperature difference between cooling side / heat radiation side is 70 ~ 75 ℃)
Was applied for 7.5 seconds, and 72 cycles were carried out.

The internal resistance (R2) after the test was measured, and the rate of change in resistance was determined. As a result, it was confirmed that all the thermomodules had an increase of about 0.5%, and the thermomodule 10 sufficiently functions.

Example 13 (corresponding to claim 16) Even in a conventional thermomodule using lead-tin eutectic solder (melting point 183 ° C) or tin antimony solder (melting point 232 ° C), when the substrate size becomes large. Since the substrate itself warps, the thermoelectric semiconductor element in the central portion of the thermomodule may be in a floating state without being bonded to one of the substrate metallization layers.

In order to avoid such an assembly defect,
The same solder as that of the thermoelectric semiconductor element is coated on the metallized surface of the substrate to reduce the assembly failure.

A similar phenomenon is feared even when gold tin is used as a bonding agent, and therefore, in the present example, preliminary soldering of gold tin to the substrate side metallized surface was performed.

In other words, this embodiment is based on the ceramic substrate 1
The thermo-module is assembled after the gold-tin layer is formed on both the metallized layers 1 and 12 (lands) and the thermoelectric semiconductor elements 13a and 13b.

FIG. 22 is a diagram showing a thermo module assembly process in this embodiment.

As shown in FIG. 22, in the preliminary soldering of gold tin on the metallized surface of the substrate in this embodiment, a predetermined amount of commercially available gold tin paste was used for the metallized layers (land portions 111, 121) of the ceramic substrates 11, 12. ) [Fig. 22
(See (a)], and then 320 in a reducing atmosphere in a vacuum furnace.
The heating was performed at 1 ° C. for 1 minute [see FIG.

The ceramic substrates 11 and 12 used are alumina-made 47-pair land portion-holding substrates and have an external dimension of approximately 6 m.
It is mx 14 mm. The thickness of the preliminary solder was about 10 μm from the cross-section observation.

Ceramic substrates 11 and 12 having preliminary hands obtained through the steps of FIGS. 22A and 22B, and a gold tin layer formed on the outermost surface obtained by, for example, the method shown in FIG. Module assembly is performed using the thermoelectric semiconductor elements 13a and 13b to obtain thermoelectric semiconductor elements 13a and 13b.
A gold-tin-bonded thermo module 10 in which the gold tin layers 113 and 123 are bonded between the substrate 11 and the substrate 11 and 12 [FIG.
(See (c)].

The assembly of the gold-tin jointed thermo module 10 in this example was carried out in the same manner as in Example 3 except that preliminary soldering was performed on the ceramic substrates 11 and 12.

For comparison, a level (module) without preliminary soldering was prototyped, the internal resistance (R1) after the lead wire was attached was measured, and the resistance from the internal resistance (R2) after the thermal shock test and the reverse current test was measured. The rate of change was determined, and the rate of non-defective products (when the rate of change was less than or equal to the reference value was judged as non-defective) was compared.

As a result, the rate of non-defective products was 100% when gold tin was preliminarily soldered to the substrates 11 and 12 and assembled, whereas 80% of the modules were prototyped without preliminary soldering. These tendencies are often observed in thermomodules using tin antimony solder.

From this fact, the ceramic substrates 11 and 12 are
It has been clarified that the defective soldering can be reduced by carrying out preliminary soldering of gold and tin.

Example 14 (corresponding to claim 17) In this example, as in Example 3, the alumina substrates 11 and 12 having 21 pairs of land portions and a 35 μm thick gold-tin foil fused thermoelectric semiconductor were used. Using the elements 13a and 13b, the joining conditions were examined in a vacuum furnace in a reducing atmosphere.

The temperature in the vicinity of the joint surface in this case was measured by fixing a thermocouple on the back surface side of the substrates 11 and 12 with a heat resistant tape.

The temperatures thus measured are 300 ° C., 320 ° C., 340 ° C. in addition to 280 ° C. which is the melting point of gold tin.
Under the temperature conditions of 5 seconds, 10 seconds, 20 seconds, 30 seconds, 1 minute,
As a result of joining under the conditions of 3 minutes and 5 minutes, it was confirmed that joining was possible by heating to 280 ° C., which is the melting point, for 10 seconds or more. However, about 1 minute of heating time was required to realize a so-called “wet state” in which gold and tin flowed through the substrate metallization (land portion) in general.

The durability of the thermomodule produced under the above temperature and time conditions is the same as that of the thermomodule produced under the respective conditions.
As a result of evaluation by an acceleration test in which reversal energization was conducted at 7.5 second intervals so that the temperature difference of 1 became 80 ° C., no junction temperature dependency was observed, and any thermomodule heated for 10 seconds or more had a 20,000 cycle cycle. It showed durability. However, the sample with a heating time of 5 seconds was not practical because the resistance of most of the modules increased after 2000 cycles.

From the above, the ceramic substrates 11, 1
When gold tin is used for joining 2 and the thermoelectric semiconductor elements 13a and 13b, it has become clear that it is necessary to heat to a temperature of at least the melting point for 10 seconds or more.

Example 15 (corresponding to claim 18) In this example, the thickness of the gold-tin layer fused to both surfaces of the thermoelectric semiconductor elements 13a and 13b was changed from 20 μm to 50 μm to form a thermostat. The module was assembled.

In the conventional lead-tin type solder and tin antimony type solder, the thickness of the solder layer after joining is 10 to 20 μm regardless of the amount of solder in the thermoelectric semiconductor element. The thickness of the gold-tin fused to the semiconductor elements 13a and 13b is almost the same as the thickness of the gold-tin and is bonded. In this example, a load larger than that of the conventional module was applied at the time of joining, and the thickness of the joining layer was changed within the range of 5 μm to 50 μm.

After the module was assembled, a copper tungsten plate having a thickness of 1 mm was joined to both ends of the thermomodule with tin-silver-copper solder, and a thermal shock test was repeated in which temperature cycles of -40 ° C and 85 ° C were repeated.

The rate of change in resistance after 100 cycles of the above thermal shock test was less than 5% of the pass / fail judgment at any junction thickness level (module),
It was confirmed that it was within the practical range. Therefore, the thickness of the tested gold-tin layer of 5 μm to 50 μm is considered to be an appropriate range for producing the durable gold-tin bonded thermomodule 10.

Example 16 (corresponding to claim 19) In this example, after the module was assembled in the test stage, a gold tin paste having a gold content in the solid content of about 80% by weight was used as a power source. The lead wire 15 for supply was attached.

The gold-tin paste used is a commercial product, flux type is RMA type, and viscosity is about 200 Pa · s. As a concrete method, a soldering hand was used to join the metallized layer of the substrate and the tin-plated copper wire in the air.

Separately, the adhesion force when the φ0.3 tin-plated copper wire is joined to a plate whose outermost surface of pure nickel is gold-plated and joined with tin antimony solder as a comparative sample, and the adhesion force due to the gold-tin joining described above are shown. , Peel test
(Pulling the lead wire 15 in the direction perpendicular to the joint surface) for comparison.

The gold-tin joints all showed strengths of 2 kgf or more, while the tin-antimony solder joints also had some samples that caused f solder breakage at 1 kgf to 1.5 kg. From this, it was confirmed that the joining with gold-tin was sufficient in terms of strength.

Next, a lead-wire 15 was formed by using gold-tin paste on the 31-to-land portion gold-tin joint thermomodule 10 manufactured by the same method as that of the third embodiment.
Was attached.

FIG. 23 is a conceptual diagram showing the lead wire attaching step in this embodiment. As shown in FIG. 23, in this embodiment, the lead wire mounting land portion 11 formed at the end of the pattern surface of the heat dissipation side substrate 11 of the thermo module 10 is formed.
Gold tin paste satisfying the eutectic composition component ratio is arranged on 2a-1 and 112a-2, and a pair of lead wires 15 are arranged thereon.

The lead wire 15 used for the thermomodule 10 is a tin-plated copper wire having a wire diameter of φ0.3 mm and joined by soldering. The surface condition after joining was smooth, and pit-shaped holes called blowholes were not seen.

[0250] The gold-tin jointed thermo module 10 thus prepared was judged by the thermal shock test and the reverse electrification test, and it was confirmed that all 30 prototypes functioned as thermo modules.

Also, this gold-tin joint thermo module 1
A copper-tungsten plate with a thickness of 1 mm was attached to 0 with tin-silver-copper solder, and durability was evaluated by reversal energization. I was not able to admit.

Embodiment 17 (corresponding to claim 19) In this embodiment, lead wires are joined to the assembled thermo module by using gold-tin pellets.

In the test stage, first, a pure nickel plate was gold-plated and a 50 μm-thick gold tin foil was punched to a diameter of 1 mm to obtain a diameter of φ1 mm.
An attempt was made to join a 0.3 mm tin-plated copper wire.

In both cases of fusion bonding in a reducing atmosphere in a vacuum furnace and fusion bonding in air using a soldering hand,
In each case, it was confirmed that there was sufficient bonding strength.

Next, a prototype 3 was prepared in the same manner as in Example 3.
The lead wire 15 was attached to the gold-tin bonded thermomodule 10 having one pair of lands by using gold-tin pellets.

The lead wire 15 used here has a wire diameter of 0.3 m.
A tin-plated copper wire of m was used for joining in air using a soldering hand. The surface condition after joining was smooth and there were no pits.

[0257] The thermo-module 10 with the gold-tin joint lead thus prepared was judged by the thermal shock test and the reversal energization test, and it was confirmed that all 30 prototypes functioned as thermo-modules.

Example 18 (Corresponding to Claim 20) In this example, a post made of nickel was used instead of the lead wire 15 used in Example 17, and post mounting of the gold-tin jointed thermo module 10 after assembly. It is to join the position.

The nickel post is obtained by plating the outer peripheral portion of a nickel plate with gold and then cutting it into pieces of about 1 mm square. In recent years, it has been widely used in place of the lead wire 15 in the optical communication field.

In the experiment, the thermo module 1 after assembly was used.
Apply gold-tin paste to the 0 post mounting position, place nickel posts on this, and place in a vacuum furnace for 350
Bonding was carried out under the condition of 1 ° C. for 1 minute. The specific joining procedure is
This is similar to Example 19 described later.

When the transverse rupture strength after joining is compared with that of tin antimony solder joint which is usually used, it is confirmed that the strength is more than double, and the effectiveness of using gold tin for joining posts is confirmed. It could be confirmed.

Example 19 (corresponding to claim 20) As a lead member for supplying power in a thermo module, instead of the lead wire 15 used in Example 17, generally
A metal square pole (post) of 1 mm square and 2 mm height may be used.

In this example, gold tin was used for joining the metal post and the metallized layer (land portion) on the substrate.

In particular, in this embodiment, the substrates 11, 12 and the thermoelectric semiconductor elements 13a, 13a,
Thermo module 1 in which the joints between 13b are made of gold and tin
After assembling 0, the gold-tin joint thermo module 10
On the other hand, a metal post for power supply was attached using a gold-tin paste having a gold content in the solid content of about 80% by weight.

The gold-tin paste used is a commercial product, flux type is RMA type, and viscosity is about 200 Pa · s.

The joining was performed by the procedure as shown in FIG. 24, for example. First, post mounting positions (post mounting land portions 112b-1 and 112b-) provided on the ceramic substrate 11 of the thermo module 10 after assembly.
2) is coated with the gold-tin paste [see FIG. 24 (a)], and then a pair of nickel-plated posts 16 plated with gold are placed on the gold-tin paste [see FIG. 24 (b)], After that, post-bonding was performed under a heating condition of 350 ° C. for 1 minute while pressing with a jig for preventing misalignment [see FIG. 24 (c)].

In this post-joining step, it was not possible to confirm whether the gold-tin layers 113, 123 used for joining the thermoelectric semiconductor elements 13a, 13b to the ceramic substrates 11, 12 were remelted. Was not recognized.

After joining, a tin-plated copper wire of φ0.3 was attached to the upper surface of the post 16 by a gold-tin paste, a thermal shock and reverse current test were conducted, and the temperature difference between the heat radiation side substrate 11 and the cooling side substrate 12 was measured. It was confirmed that a predetermined temperature difference of 70 ° C was generated.

Therefore, it is possible to bond the posts for power supply by using the gold-tin paste, and it is possible to prepare the gold-tin bonding thermomodule 10 using gold-tin having the eutectic composition as the solder for assembly. Is.

Example 20 (Corresponding to Claim 20) In this example, gold tin paste having a diameter of 1.2 mm and a thickness of 50 μm was used instead of the gold tin paste used in Examples 18 and 19. It is used to join the metal post to the thermo module.

Specifically, a gold-tin joint thermomodule 10 assembled by using the alumina substrates 11 and 12 having 23 pairs of lands and the gold-tin fused thermoelectric semiconductor elements 13a and 13b described in the fifth embodiment is prepared. , The joint surface (1 mm square) has a gold-plated finish and a height of 2 mm, a nickel post with a diameter of 1.2 m
Bonding to the post mounting position was performed using gold-tin pellets of m and a thickness of 50 μm.

The joining conditions were heating in a vacuum furnace at 350 ° C. for 1 minute, and an aluminum jig was used for the purpose of preventing displacement during joining.

After joining the nickel post, a φ0.3 mm tin-plated copper wire was attached to the top surface of the post with gold-tin paste, the internal resistance (R1) was measured, and then -40 ° C / 85 ° C (30 ° C).
Min / cycle, 20 cycles) thermal shock test and reverse electrification test (achievement temperature difference between cooling side / heat radiation side is 70 ~ 75 ℃)
Was applied for 7.5 seconds, and 72 cycles were carried out.

The internal resistance (R2) after the test was measured, and the rate of change in resistance was determined. As a result, it was confirmed that all the thermomodules had an internal rate of change in resistance of about 0.5%, and that they functioned sufficiently as thermomodules.

Example 21 (Claims 21 to 2)
In this example, a metal post is bonded in advance to a metallized layer forming substrate (heat dissipation side substrate 11) before assembling the thermoelectric semiconductor elements 13a and 13b by gold-tin paste, and then,
Substrate 11 to which this post is joined and the other substrate 12
The thermoelectric semiconductor elements 13a and 13b are provided between (the cooling side substrate)
Are joined together to assemble a thermo module.

The substrate 11 used in this example is an alumina substrate having 23 pairs of lands, and is a P-type thermoelectric semiconductor element 13
a and the pattern (land portion 111) for mounting the N-type thermoelectric semiconductor element 13b at 23 places, and the pattern for mounting the post (post mounting land portions 112b-1 and 11b).
2b-2) is metallized in two places.

The other ceramic substrate 12 does not have the above-mentioned pattern for attaching the post, and only the element mounting pattern (land portion 121) is formed in 23 places.

The material of the post is pure nickel, and the size is 1 mm square on the bottom and 1.8 mm high, and 0.25 to 0.3 on both sides of the 1 mm square.
5μm gold plating finish is performed.

The post joining and module assembling steps in this embodiment were performed in the procedure shown in FIG. 25, for example.

First, post mounting positions (post mounting land parts 112b-1 and 112b) provided on the heat dissipation side ceramic substrate 11 before being assembled as a module.
b-2) is coated with a gold tin paste [see FIG. 25 (a)], and then a pair of nickel posts 16 plated with gold as described above are placed on the gold tin paste to prevent misalignment. Post bonding was carried out under a heating condition of 350 ° C. for 1 minute while pressing with a jig for use [see FIG. 25 (b)].

Thereafter, with the nickel posts 16 attached to the heat dissipation side substrate 11, the thermoelectric semiconductor elements 13a, 13b are provided.
In addition, the cooling side substrate 12 was attached to perform module assembly.

Specifically, a highly viscous flux is applied to the land portion 11 of the heat dissipation side substrate 11 on which the nickel posts 16 are standing, and a P-type thermoelectric semiconductor element 13a having tin antimony solder layers on both surfaces thereof is applied. And N-type thermoelectric semiconductors were arrayed and heat-bonded in this state to produce a π set state module [see FIG. 25 (c)].

In the joining at the π-set state module generation stage, the heat source set temperature was 320 ° C. and the heating time was 12 seconds. Usually, the temperature of the joint surface is lower than the heat source temperature by about 50 ° C., so that the nickel post 16 previously attached did not cause a positional deviation.

Next, after cleaning the substrate 11 of the obtained π-group module, the heat radiation side substrate 12 is attached to the land portion 121 thereof.
Was superposed such that the pair of corresponding thermoelectric semiconductor elements 13a and 13b were aligned with each other, and then heat-bonded under a heating condition of 320 ° C. for 18 seconds (see FIG. 25 (d)).

In the example of FIG. 25, after the nickel posts 16 are attached to the heat dissipation side substrate 11, the thermoelectric semiconductor elements 13a and 13b are attached to the heat dissipation side substrate 11 to form a π set state module and then cooled. Although the gold-tin joint thermo module 10 is completed by attaching the side substrate 12, as another method, after the nickel post 16 is attached to the heat dissipation side substrate 11, the cooling side substrate in which the post 16 is not standing is provided. After the thermoelectric half elements 13a and 13b are mounted on 12 to form a π set state module, the π set state module is combined with the heat radiation side substrate 11 on which the post 16 is standing to complete the gold-tin joint thermo module 10. There is also a good method.

FIG. 26 is a diagram showing a post joining and module assembling process procedure based on this other method.

In this case, after the nickel posts 16 are attached to the heat dissipation side substrate 11 by the same method as shown in FIGS. 25 (a) and 25 (b) [see FIGS. 26 (a) and 26 (b)], the nickel posts 1 are formed.
A high-viscosity flux is applied on the land portion 121 of the cooling-side substrate 12 where 6 is not standing, and P-type thermoelectric semiconductor elements 13a and N having tin antimony solder layers on both surfaces are applied thereon.
The type thermoelectric semiconductors 13b were arranged and heat-bonded in this state to produce a π-group state module [see FIG. 26 (c)].

Next, the substrate 1 of this π-group state module
2 is reversed so that the pair of thermoelectric semiconductor elements 13a and 13b attached to the land 121 is aligned with each pair of the land 111 of the heat radiation side substrate 11 (previously applied with high-viscosity flux). Then, the substrate 12 is superposed on the heat radiation side substrate 11 and bonded by heating [FIG.
See (d)].

After the φ0.3 tin-plated copper wire was attached to the nickel post 16 of the gold-tin joint thermomodule 10 obtained through the process of FIG. 25 or FIG. 26 by tin antimony solder, the internal resistance (R1) was measured. Then -40 ℃
/ 85 ° C (30 minutes / cycle, 20 cycles) thermal shock test and reversing current test (current is applied so that the temperature difference between the cooling side and the radiating side reaches 70 to 75 ° C, 7.5 seconds switching, 72
Cycle).

The internal resistance (R2) after the test was measured, and the rate of resistance change was calculated.
It was an increase of about a percentage, and it was confirmed that it functions sufficiently as a thermo module.

The solder used for module assembly in this example is tin antimony solder having a lower melting point than gold tin.
(Melting point 232 ° C.) was used. Usually, when the same kind of solder is used, after mounting the post 16, the elements 13a, 13
Although it is not possible to assemble b, in the present embodiment, the melting point of gold-tin used for joining the posts 16 is much higher than that of tin antimony solder, so that the posts 16 attached earlier are used.
Since it is possible to assemble without causing the positional deviation, the effectiveness of this method was confirmed.

From each of the embodiments described above, the effectiveness of joining the ceramic substrate 11 and the post 16 with the gold-tin layer was confirmed.

Next, the usage of the gold-tin joint thermo module 10 of the present invention will be described.

Gold-tin-bonded thermo module 10 of the present invention
One of the uses is the precision temperature control of the laser diode of the optical communication module.

FIG. 27 is a diagram showing a conceptual sectional structure of an optical communication module 100 in which the gold-tin joint thermomodule 10 of the present invention is mounted.

In this optical communication module 100, the gold-tin joint thermo module 10 manufactured based on the research results in each of the above-described embodiments is mounted inside the package 60.

More specifically, the package 60 is mounted so that the non-patterned surface of the heat radiation side ceramic substrate 11 of the gold-tin bonding thermomodule 10 is in contact with the inner bottom surface of the package 60. Also, in this state, the gold-tin joint thermo module 1
On the non-patterned surface of the cooling side ceramic substrate 12 of 0,
For example, a laser diode 30 which is a light source of the optical communication module 100 is arranged via a heat spreader 20 made of CuW (copper-tungsten alloy).

The laser diode 30 receives power from a controller (not shown) and generates laser light modulated by predetermined transmission data. This laser light is transmitted through the optical fiber 40
And is transmitted to the inside of the optical fiber 40 toward a predetermined receiving circuit.

A thermistor 50 is provided on the heat spreader 20. The control unit uses the thermistor 5
The cooling temperature of the cooling side substrate 12 is variably controlled by controlling the power supply to the gold-tin joint thermo module 10 based on the temperature detected by 0. As a result, the laser diode 30 is controlled to the target temperature and always maintains an appropriate oscillation frequency.

When assembling the optical communication module 100 according to the present invention, the heat spreader 20, the cooling side ceramic substrate 12 of the gold-tin joining thermo module 10 and the laser diode 30 are joined by, for example, tin antimony solder.

Here, the melting point temperature (232 ° C.) of tin antimony solder is determined by the ceramic substrates 11 and 12 and the thermoelectric semiconductor elements 13 a of the gold-tin junction thermomodule 10.
The melting point temperature of the gold-tin layer used for joining between 13b (280
Much lower than ℃).

That is, in the optical communication module 100 according to the present invention, the gold-tin joint thermo module 10 is used.
Can be incorporated and mounted inside the package 60 without causing an influence of melting or the like on the gold-tin layer of the thermo module 10.

Further, the optical communication module 1 according to the present invention
According to No. 00, the gold-tin bonding thermomodule 10 can be incorporated by using tin antimony solder (melting point 232 ° C.) having a higher melting point temperature without using lead-tin eutectic solder (melting point 183 ° C.). The thermo module 1
0 itself uses the bonding agent (gold tin) containing no lead component as described above, the optical communication module 100
It can also be lead-free as a whole.

Further, the gold-tin joint thermo module 10 mounted on the optical communication module 100 has a high Young's modulus between the P-type thermoelectric semiconductor element 13a and N-type thermoelectric semiconductor element 13b and the ceramic substrates 11 and 12, and has creep resistance. Due to the good gold-tin layer bonding structure, the ceramic substrates 11 and 12 are less likely to be deformed even when a thermal change occurs.

Accordingly, in particular, the laser diode 30
It is possible to suppress the deformation of the ceramic substrate 12 on the cooling side due to the thermal change and reduce the influence of the deformation on the attitude change of the laser diode 30, and as a result, the optical axis of the laser diode 30 with respect to the thermal change. The deviation can be significantly reduced.

As described above, the gold-tin-bonded thermo module 10 according to the present invention has a structure in which the P-type and N-type thermoelectric semiconductor elements and the ceramic substrate are bonded by the gold-tin layer, thereby making them lead-free and optical. This can contribute to two aspects of stabilizing the optical axis of the laser diode when it is used for precise temperature control of the laser diode 30 of the communication module 100.

The present invention is not limited to the embodiments described above and shown in the drawings, but can be appropriately modified and implemented within the scope of the invention.

For example, in the above-mentioned embodiment, the gold-tin joint structure was described on the premise of the thermo-module used for precise temperature control of the laser diode 30 of the optical communication module 100, but the gold-tin joint structure of the present invention has other uses. It is also applicable to the thermo module of.

[0309]

As described above, according to the present invention,
Between the P-type and N-type thermoelectric semiconductor elements and the ceramic substrate,
Since the structure is such that a gold-tin eutectic composition bonding agent having a gold content of approximately 80% by weight is used for bonding, the gold-tin bonding Peltier device thermoelectric exchange module is used for precise temperature control of a laser diode of an optical communication module, for example. In this case, the thermoelectric conversion module can be joined to the laser diode or the like by using a solder whose melting point temperature is lower than that of the gold-tin layer and higher than that of lead-tin solder, and the thermoelectric conversion module can be securely incorporated into the optical communication module. In addition to being able to do so, lead-free as seen from the whole optical communication module can be realized.

The gold-tin-bonded Peltier device thermoelectric conversion module incorporated in the optical communication module has a higher Young's modulus than lead-tin solder and has a strong bonding structure using a gold-tin layer having good creep resistance. The deformation of the ceramic substrate with respect to the change is small, and it is possible to contribute to the prevention of the optical axis shift of the laser diode with respect to the temperature change while suppressing the influence on the posture deformation of the laser diode joined to the thermoelectric conversion module.

[Brief description of drawings]

FIG. 1 is a view showing a conceptual side structure of a gold-tin junction Peltier element thermoelectric conversion module according to the present invention.

FIG. 2 is a diagram showing a thermoelectric semiconductor element production process according to the first embodiment.

FIG. 3 is a view showing a structure of a metallized layer formed on a ceramic substrate.

FIG. 4 is a diagram showing a module assembly process according to the first embodiment.

FIG. 5 is a diagram showing a module assembly process following the process in FIG.

FIG. 6 is a diagram showing a module assembly process according to the second embodiment.

FIG. 7 is a diagram showing a module assembly process following the process in FIG. 6;

FIG. 8 is a view showing a thermoelectric semiconductor element producing process according to the third embodiment.

FIG. 9 is a diagram showing a module assembly process according to the third embodiment.

FIG. 10 is a diagram showing a module assembly process following the process in FIG. 9;

FIG. 11 is a diagram showing a thermoelectric semiconductor element producing process according to the fourth embodiment.

FIG. 12 is a diagram showing a thermoelectric semiconductor element production process according to Example 5;

FIG. 13 is a diagram showing a thermoelectric semiconductor element producing process according to Example 6;

FIG. 14 is a view showing a thermoelectric semiconductor element producing process according to the seventh embodiment.

FIG. 15 is a diagram showing a state in which the joined state of the thermomodule obtained in Example 7 is observed from the side surface.

FIG. 16 is a diagram showing a state in which the joined state of the thermomodule obtained in Example 2 is observed from the side surface.

FIG. 17 is a diagram showing a step of forming a gold tin layer on the outermost surface of the thermoelectric semiconductor element according to Example 8;

FIG. 18 is a diagram showing a thermoelectric semiconductor element producing process according to Example 9;

FIG. 19 is a conceptual diagram showing a surface state of a gold-tin foil fusion-bonded thermoelectric semiconductor wafer according to Example 10.

FIG. 20 is a diagram showing a thermoelectric semiconductor element production process according to Example 10;

FIG. 21 is a diagram showing a module assembly process according to the twelfth embodiment.

FIG. 22 is a view showing a module assembling process according to the thirteenth embodiment.

FIG. 23 is a conceptual diagram showing a lead wire attaching step according to the sixteenth embodiment.

FIG. 24 is a conceptual diagram showing a post attachment process according to Example 19;

FIG. 25 is a diagram showing an example of a post joining and module assembling process in Embodiment 21.

FIG. 26 is a view showing another example of post joining and module assembling steps in the twenty-first embodiment.

FIG. 27 is a diagram showing a configuration of an optical communication module in which the thermo module of the present invention is mounted.

FIG. 28 is a conceptual diagram showing a general configuration of a thermo module.

[Explanation of symbols]

10 ... Gold-tin junction Peltier element thermoelectric conversion module (thermo module), 11 ... Ceramic substrate (heat radiation side),
111 ... Land portion (metallized layer), 1111 ... Copper metallized layer, 1112 ... Nickel metallized layer, 1113
... Gold plating, 112a-1, 112a-2 ... Lead wire mounting land portion, 112b-1, 112b-2 ... Post mounting land portion, 113 ... Gold tin layer, 114 ... Back surface metallization layer, 1141 ... Copper metallization layer, 1142 ... Nickel metallization layer, 1143 ... Gold plating, 12 ... Ceramic substrate (cooling side), 121 ... Land portion (metallization layer), 1
23 ... Gold-tin layer, 124 ... Backside metallization layer, 15 ... Lead wire, 16 ... Metal post, 70 ... Ingot, 71
... P-type / N-type thermoelectric semiconductor wafer, 170 ... Carbon jig, 171 ... Plate, 172 ... Reamed hole, 100 ...
Optical communication module, 20 ... Heat spreader, 30 ...
Laser diode, 40 ... Optical fiber, 50 ... Thermistor, 60 ... Package

Claims (23)

[Claims] 1. A plurality of P-type thermoelectric semiconductor elements and N-type thermoelectric semiconductor elements, and a plurality of metallized layers on which the P-type thermoelectric semiconductor elements and N-type thermoelectric semiconductor elements are mounted in pairs, respectively. A pair of ceramic substrates bonded to the upper and lower sides of each thermoelectric semiconductor element so as to be electrically connected in series via the corresponding metallization layers, and a lead member mounting metallization provided on one of the ceramic substrates. A lead wire or a metal post for supplying power, which is joined to the layer, and between the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element and the metallized layer of the pair of ceramic substrates,
A gold-tin-bonded Peltier device thermoelectric conversion module, which is bonded using a gold-tin eutectic composition bonding agent having a gold content of approximately 80% by weight. 2. A paste having a gold-tin eutectic composition having a gold content in the solid content of about 80% by weight is previously applied to the metallized layer of the ceramic substrate as the bonding agent, and the paste corresponding to the paste is applied. The gold-tin-bonded Peltier device thermoelectric conversion module according to claim 1, wherein each thermoelectric semiconductor element is arranged and the paste is heated and melted to bond between the metallized layer and each thermoelectric semiconductor element. . 3. The content of gold as the bonding agent is approximately 8
By placing 0 weight percent of gold tin pellets on the metallized layer of the ceramic substrate, arranging the corresponding thermoelectric semiconductor elements on the gold tin pellets and heating and melting the gold tin pellets, the metallized layer and each of the metallized layers are formed. The gold-tin-bonded Peltier element thermoelectric conversion module according to claim 1, wherein the thermoelectric semiconductor elements are gold-tin bonded. 4. A gold-tin layer having a gold-tin eutectic composition having a gold content of about 80% by weight is previously formed on the outermost surfaces of the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element, and then the ceramic substrate. The gold-tin-bonded Peltier device thermoelectric conversion module according to claim 1, which is bonded to the metallized layer of. 5. A gold-tin layer having a gold-tin eutectic composition having a gold content of about 80% by weight is provided on the surfaces of the P-type thermoelectric semiconductor block and the N-type thermoelectric semiconductor block, and each block is provided with the thermoelectric conversion module. The gold-tin layer on the outermost surface of the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element is cut into the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element having a size suitable for assembly. 5. The gold-tin-bonded Peltier element thermoelectric conversion module according to claim 4, wherein the thermoelectric semiconductor element and the N-type thermoelectric semiconductor element are provided before shredding. 6. Before providing the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element with the gold tin layer on the outermost surface of each thermoelectric semiconductor element before shredding, the content of gold is approximately 80% by weight. A foil or foil having a gold-tin eutectic composition is heat-sealed to each block, and each block has a size suitable for assembling the thermoelectric conversion module.
6. The gold-tin junction Peltier element thermoelectric conversion module according to claim 5, wherein the thermoelectric semiconductor element and the N-type thermoelectric semiconductor element are formed by cutting into small pieces. 7. A gold-tin eutectic composition having a gold plating layer on the outermost surfaces of the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element, and the gold content on the gold plating layer is approximately 80% by weight. The gold-tin-bonded Peltier element thermoelectric conversion module according to claim 6, wherein the foil or foil is heat-sealed. 8. The P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element have the gold plating layer on a nickel layer, and the thickness of the gold plating layer is 0.01 μm or more and 20 μm or less. The gold-tin junction Peltier element thermoelectric conversion module described. 9. The P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element each have a tin plating layer on the outermost surface, and a gold-tin eutectic composition having a gold content of about 80% by weight on the tin plating layer. The gold-tin-bonded Peltier element thermoelectric conversion module according to claim 6, wherein the foil or foil is heat-sealed. 10. The thickness of the gold-tin foil or foil having the eutectic composition which is heat-sealed to the outermost surfaces of the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element is 20 μm or more.
The gold-tin junction Peltier element thermoelectric conversion module according to claim 6, wherein the thickness is 0 μm or less. 11. When the gold-tin layer is provided on the outermost surface of each of the P-type thermoelectric semiconductor elements and the N-type thermoelectric semiconductor elements before shredding, the gold content is approximately 80.
An alloy layer having a weight percent of gold-tin eutectic composition is electrolytically deposited on the surface of each block, and each block has a size suitable for assembling the thermoelectric conversion module. The gold-tin junction Peltier element thermoelectric conversion module according to claim 5, wherein the thermoelectric conversion module is formed by cutting into a semiconductor element. 12. A P-type thermoelectric semiconductor block and an N-type thermoelectric semiconductor block are shredded into the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element having a size suitable for assembling the thermoelectric conversion module, and then the P-type thermoelectric semiconductor block is cut. The gold-tin-bonded Peltier element thermoelectric conversion module according to claim 4, wherein the gold-tin layer is provided on the outermost surfaces of the thermoelectric semiconductor element and the N-type thermoelectric semiconductor element. 13. A metal layer containing nickel as a main metal element is provided between the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element and the bonding layer made of the gold-tin eutectic composition. The gold-tin junction Peltier element thermoelectric conversion module according to 1. 14. The gold according to claim 13, wherein the adhesion strength between the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element and the metal layer is 50 kg / cm 2 or more, preferably 80 kg / cm 2 or more. Tin junction Peltier element thermoelectric conversion module. 15. A metal-tin layer having the gold-tin eutectic composition is provided on the outermost surface of the metallized layer of the ceramic substrate, and the metallized layer and the thermoelectric semiconductor elements are melted by heating and melting the gold-tin layer. The gold-tin joint Peltier element thermoelectric conversion module according to claim 1, characterized in that a gold-tin joint is provided between the two. 16. A gold-tin layer composed of the gold-tin eutectic composition is provided on both the outermost surfaces of the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element, and the outermost surface of the metallized layer of the ceramic substrate, The gold-tin-bonded Peltier element thermoelectric conversion module according to claim 1, wherein gold-tin bonding is performed between the metallized layer and each of the thermoelectric semiconductors by heating and melting both gold-tin layers. 17. A gold-tin layer having the eutectic composition is provided between the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element and the metallized layer of the ceramic substrate, and the temperature of the gold-tin layer is equal to or higher than the melting point of gold tin. The gold-tin-bonded Peltier element according to claim 1, wherein the gold-tin layer is melted by heating at a temperature for 10 seconds to 5 minutes to bond the metallized layer to each thermoelectric semiconductor. Thermoelectric conversion module. 18. The metallized layer by heating with a gold-tin layer of the eutectic composition provided between the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element and the metallized layer of the ceramic substrate. And the thermoelectric semiconductor elements are joined together, and the thickness of the gold-tin layer remaining at the joint between the P-type thermoelectric semiconductor element and the N-type thermoelectric semiconductor element and the metallized layer of the ceramic substrate after the heating and joining is from 5 μm. The gold-tin junction Peltier element thermoelectric conversion module according to claim 1, wherein the thermoelectric conversion module has a thickness of 50 μm. 19. The lead wire having a gold content of approximately 8
The gold-tin-bonded Peltier device thermoelectric conversion module according to claim 1, wherein the gold-tin eutectic composition bonding agent is bonded to the lead member mounting metallization layer using 0 weight percent. 20. The metal post according to claim 1, wherein the metal post is bonded to the lead member mounting metallized layer by using a gold-tin eutectic composition bonding agent having a gold content of about 80% by weight. Gold-tin junction Peltier element thermoelectric conversion module. 21. A plurality of P-type thermoelectric semiconductor elements and N-type thermoelectric semiconductor elements, a pair of ceramic substrates bonded to the upper and lower sides of the P-type thermoelectric semiconductor elements and N-type thermoelectric semiconductor elements, and one of the ceramic substrates Has a metal post for power supply joined to the lead member mounting metallization layer provided as a main component, and for joining the metal post and the lead member mounting metallization layer of the one ceramic substrate, A gold-tin junction Peltier element thermoelectric conversion module, characterized in that gold-tin having a eutectic composition of gold and tin containing approximately 80% of gold in percent is used. 22. The metal posts are bonded to the lead member mounting metallized layers of the pair of ceramic substrates by the gold tin, and the thermoelectric semiconductor elements are disposed and bonded between the ceramic substrate and the other ceramic substrate. 22. The thermoelectric conversion module according to claim 21, characterized in that the thermoelectric conversion module is assembled. 23. After assembling the thermoelectric conversion module by bonding the pair of ceramic substrates to the upper and lower sides of each thermoelectric semiconductor element, the metal post and the lead member mounting metallization layer of the one ceramic substrate are assembled. 22. The gold-tin jointed Peltier device thermoelectric conversion module according to claim 21, wherein the thermoelectric conversion module is joined to.