JP2005191040A - Thermoelectric module manufacturing method and positioning jig used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a thermoelectric module which can manufacture the thermoelectric module by arranging accurately thermoelectric elements and further using a solder paste to assure the function of the thermoelectric module having excellent mass productivity and further which does not damage the thermoelectric element. <P>SOLUTION: The method of manufacturing the thermoelectric module includes a step of arranging a wiring conductor on a support substrate, a step of laminating a plurality of positioning jigs having a plurality of apertures above the wiring conductor, a step of deviating and disposing the mutual apertures, a step of inserting the thermoelectric elements into the through holes made of the apertures of the plurality of the laminated positioning jigs, a step of heating and connecting the thermoelectric element to the wiring conductor, then a step of moving the positioning jigs, and a step of removing the positioning jigs from the thermoelectric elements. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a thermoelectric module that is suitably used for cooling a heating element such as a semiconductor and has excellent mass productivity.

  Conventionally, a thermoelectric element using the Peltier effect has been used as a thermoelectric element for cooling because one end generates heat and the other end absorbs heat when an electric current is passed. In particular, temperature control of laser diodes as thermoelectric modules, small size and simple structure, cooling devices without refrigerators, refrigerators, thermostats, photodetectors, electronic cooling elements such as semiconductor manufacturing equipment, temperature control of laser diodes, etc. Use is expected.

The thermoelectric element material used for the thermoelectric module used near room temperature is from A ₂ B ₃ type crystal (A is Bi and / or Sb, B is Te and / or Se) from the viewpoint of excellent cooling characteristics. A thermoelectric element is generally used.

For example, a solid solution of Bi ₂ Te ₃ (bismuth telluride) and Sb ₂ Te ₃ (antimony telluride) is used for a P-type thermoelectric element, and Bi ₂ Te ₃ and Bi ₂ Se ₃ (for a N-type thermoelectric element). Since the solid solution with bismuth selenide shows particularly excellent performance, this A ₂ B ₃ type crystal (A is Bi and / or Sb, B is Te and / or Se) is widely used as a thermoelectric element. .

  As shown in FIG. 1, in the thermoelectric module using the Peltier effect, wiring conductors 2a and 2b are formed on one surface of each of the support substrates 1a and 1b, and the thermoelectric element 3 is sandwiched between the wiring conductors 2a and 2b. And are arranged so as to be electrically connected in series. Here, the thermoelectric element 3 consists of two types, an N-type thermoelectric element 3a and a P-type thermoelectric element 3b, which are alternately arranged and connected by wiring conductors 2a and 2b so as to be electrically in series, and further lead By connecting to the wire 4, a DC voltage can be applied to the thermoelectric element 3 from the outside, and heat absorption or heat generation can be generated according to the direction of the current.

  The wiring conductors 2a and 2b are usually made of copper electrodes so as to withstand a large current, and the thermoelectric element 3 is joined to the wiring conductors 2a and 2b with solder.

  The thermoelectric module as described above has been attracting attention for its wide use since it has a simple structure and is easy to handle, but can maintain stable characteristics. In particular, it is small and can be locally cooled, and precise temperature control near room temperature is possible, so it is used for devices that are precisely controlled to a constant temperature, such as semiconductor lasers and optical integrated circuits, and small refrigerators. .

In producing the thermoelectric module having such a structure, as shown in the partial cross-sectional view of the thermoelectric module manufacturing method in FIG. 4, of the two support substrates arranged with the wiring conductor 21 facing upward, A lattice jig 23 formed by superposing three lattice-shaped structures 23a, 23b, and 23c having the same lattice shape at a predetermined position is disposed above any one support substrate 22, and the lattice jig 12 After inserting the thermoelectric element 25 through the bonding agent 24 made of a solder paste or the like into each of the lattice portions, at least one of the lattice jigs 23 made of the three lattice-shaped structures 23a, 23b, 23c. A method of manufacturing a thermoelectric module in which the lattice-shaped structure is horizontally moved to an appropriate position with respect to the support substrate 22 to position the thermoelectric element 25 and the wiring conductor 21 and the thermoelectric element 25 are heated and bonded is disclosed. To have. (For example, refer to Patent Document 1).
Japanese Patent Laid-Open No. 3-201579

  However, in the manufacturing method of the thermoelectric module described in Patent Document 1, the thermoelectric element is inserted into the wiring conductor on the support substrate via the lattice jig, and the lattice jig is moved horizontally to position the thermoelectric element on the wiring conductor. After the heat treatment, it was necessary to heat-bond the thermoelectric element and the support substrate with solder. In this case, when a solder paste is used for joining the thermoelectric element and the wiring conductor, when the thermoelectric element is positioned by the lattice jig, the thermoelectric element moves and the solder paste adheres to the side surface of the thermoelectric element, thereby adjacent to the thermoelectric element. It is difficult to join the thermoelectric element to the wiring conductor because the thermoelectric elements that are in contact with each other are short-circuited and the solder paste between the wiring conductor and the thermoelectric element is remarkably reduced. That is, in the above method, when solder paste is used, a problem occurs, so it is necessary to use solder plating or the like.

  Accordingly, an object of the present invention is to make it possible to manufacture a thermoelectric module using a solder paste accurately by arranging the thermoelectric element accurately in order to ensure the function of the thermoelectric module excellent in mass productivity. It is an object of the present invention to provide a method for manufacturing a thermoelectric module that does not damage the surface.

  In the method for manufacturing a thermoelectric module of the present invention, a wiring conductor is arranged on a support substrate, a plurality of positioning jigs having a plurality of openings are stacked above the wiring conductor, and the openings are shifted from each other and stacked. A thermoelectric element is inserted into a through-hole formed of the openings of the plurality of positioning jigs, and the thermoelectric elements are heated and joined to the wiring conductor, and then the positioning jig is moved to remove the positioning jig from the thermoelectric elements. It includes a step of removing.

  Further, the movement of the plurality of positioning jigs is in a horizontal direction with respect to the support substrate.

  Furthermore, the positioning jig has a lattice shape, and when the area of the through hole is S1 and the area of the end face of the thermoelectric element is S2, S1 / S2 = 1.05 to 1.90. To do.

  The positioning jig of the present invention is a positioning jig used in the method for manufacturing a thermoelectric module of the present invention, and is characterized in that a curved surface portion is formed at a corner of the opening.

  Furthermore, the radius of curvature of the curved surface portion is 50% or less of the longest side length of the opening.

Furthermore, the positioning jig is made of a material having a thermal expansion coefficient of 5.0 × 10 ⁻⁵ / ° C. or less.

  As described above, according to the method for manufacturing a thermoelectric module of the present invention, a plurality of positioning jigs having a plurality of openings are stacked, the openings are shifted from each other, and each of the stacked positioning jigs includes the openings. Positioning the thermoelectric element by inserting a thermoelectric element into the through hole, heat-joining the thermoelectric element with a wiring conductor, and then moving the positioning jig to remove the positioning jig from the thermoelectric element. Since heat bonding with the wiring conductor becomes possible later, the bonding force between the thermoelectric element and the wiring conductor is increased, the thermoelectric element is prevented from falling, and the solder paste is prevented from adhering to the side surface of the thermoelectric element. Accordingly, it is possible to manufacture a thermoelectric module having excellent mass productivity without causing a short circuit between adjacent thermoelectric elements.

  Further, the plurality of positioning jigs move in a horizontal direction with respect to the support substrate, so that the positioning jig prevents the thermoelectric element from colliding with the side surface, and the through hole is formed in the thermoelectric element. Since the thermoelectric module can be taken out after being spread out from the outer periphery, the thermoelectric module can be easily taken out from the positioning jig.

  Furthermore, since the positioning jig has a lattice shape, the clearances between the plurality of thermoelectric elements can be kept constant, so that the thermoelectric elements can be arranged with high accuracy. Further, assuming that the area of the through hole is S1 and the area of the end face of the thermoelectric element is S2, the thermoelectric element is brought into contact with the outer periphery of the through hole by setting S1 / S2 = 1.05 to 1.90. Since it can be inserted into the through-holes without any damage, it is possible to reduce scratches and plating peeling in the thermoelectric element, and to arrange the thermoelectric element with high accuracy.

  Further, by forming a curved surface portion at the corner of the opening of the positioning jig used in the manufacturing method of the thermoelectric module of the present invention, when the thermoelectric element is inserted into the through hole made of the opening, the positioning jig Damage to the side surface of the thermoelectric element can be reduced, and further, the radius of curvature of the curved surface portion is 50% or less of the longest side length of the opening, thereby further reducing the damage. Scratches and plating peeling in the thermoelectric element can be reduced.

Furthermore, since the thermal expansion coefficient of the material of the positioning jig is set to 5.0 × 10 ⁻⁵ / ° C. or less, the thermal expansion of the through hole can be suppressed. Damage due to contact with the side surface of the thermoelectric element can be reduced, and the process of removing the positioning jig from the thermoelectric element becomes extremely easy.

  FIG. 1 is a perspective view showing a thermoelectric module manufactured by the method for manufacturing a thermoelectric module of the present invention.

  As shown in FIG. 1, the thermoelectric module manufactured by the thermoelectric module manufacturing method of the present invention has wiring conductors 2a and 2b formed on one surface of each of the support substrates 1a and 1b, respectively, and the thermoelectric element 3 is wired. While being sandwiched by the conductors 2a and 2b, they are arranged so as to be electrically connected in series. Here, the thermoelectric element 3 consists of two types, an N-type thermoelectric element 3a and a P-type thermoelectric element 3b, which are alternately arranged and connected by wiring conductors 2a and 2b so as to be electrically in series, and further lead By connecting to the wire 4, a DC voltage can be applied to the thermoelectric element 3 from the outside.

  And the manufacturing method of the thermoelectric module of this invention arrange | positions the wiring conductor 2a on the support substrate 1a, and has the positioning jig 6 which has the some opening 5 shown to Fig.2 (a) above the wiring conductor 2a. A plurality of layers are stacked and the openings 5 are shifted from each other. As shown in FIGS. 2B and 2C, a thermoelectric element is inserted into the through hole 7 formed by overlapping the openings 5a and 5b of the plurality of stacked positioning jigs 6. After the element 3 is inserted and the thermoelectric element 3 is heated and joined to the wiring conductor 2 as shown in FIG. 3A, the positioning jig 6 is moved as shown in FIG. And a step of removing the positioning jig 6 from the head. As a result, the solder paste 8 necessary for firmly bonding the thermoelectric element 3 and the wiring conductor 2a can be maintained, so that the bonding force between the bonding thermoelectric element 3 and the wiring conductor 2a is increased, and the thermoelectric element 3 is prevented from falling down. By preventing the solder paste 8 from adhering to the side surface of the thermoelectric element 3, it is possible to manufacture a thermoelectric module excellent in mass productivity without causing short circuit between adjacent thermoelectric elements 3.

  Further, the movement of the plurality of positioning jigs 6 is preferably in the horizontal direction with respect to the support substrate 1a. This is because, for example, if the movement of the positioning jig 6 is perpendicular to the support substrate 1a, the thermoelectric element 3 contacts the outer periphery of the through hole 7 when the positioning jig 6 is removed from the thermoelectric element 3. This is because there is a possibility of causing scratches or plating peeling on the side surface of the thermoelectric element 3. Further, the positioning jig 6 undergoes thermal expansion due to the heat bonding of the wiring conductor 2 a and the thermoelectric element 3, and the through hole 7 becomes small. Therefore, the positioning jig 6 may not be removed from the thermoelectric element 3.

  Furthermore, when the positioning jig 6 has a lattice shape, the area of the through hole 7 is S1, and the area of the end face of the thermoelectric element 3 is S2, it is preferable that S1 / S2 = 1.05 to 1.90. This is because if the positioning jig 6 is not in a lattice shape, it is difficult to keep the clearance between adjacent thermoelectric elements 3 constant, and the thermoelectric element 3 may not be placed on the wiring conductor 2 with high accuracy. It is. Further, when S1 / S2 is less than 1.05, it becomes difficult to insert the thermoelectric element 3 into the through hole 7, and the side surface of the thermoelectric element 3 is scratched or plated when the positioning jig 6 is moved after the heat bonding. This is because peeling may occur. If S1 / S2 exceeds 1.90, the clearance between the through hole 7 and the thermoelectric element 3 increases, and it becomes difficult to place the thermoelectric element 3 on the wiring conductor 2a with high accuracy. Therefore, it is preferable that S1 / S2 = 1.05 to 1.90, and desirably S1 / S2 = 1.10 to 1.70. Further, the thermoelectric element 3 is inserted into the through-hole 7 safely and next to it. In order to prevent interference between the matching thermoelectric element 3 and the opening 5, it is desirable that S1 / S2 = 1.20 to 1.60. Here, the end face of the thermoelectric element 3 is a face that is heat-bonded to the wiring conductor 2a.

  Moreover, as shown in FIG.2 (d), it is preferable to form the curved-surface part 9 protruded outside in the corner | angular part of the opening 5. As shown in FIG. This is because, if the curved surface portion 9 is not provided at the corner portion of the opening 5, when the thermoelectric element 3 is inserted into the through hole 7, the corner portion of the opening 5 damages the side surface of the thermoelectric element 3, thereby causing plating peeling. Because there are cases. Here, it is desirable to place the curved surface portion 9 so as to protrude outside the opening 5 because the escape portion becomes wide and the thermoelectric element 3 is difficult to contact the through hole 7.

  Furthermore, the radius of curvature of the curved surface portion 9 is preferably 50% or less of the longest side length of the opening 5. This is because if the length of the longest side of the opening 5 exceeds 50%, the clearance between the opening 5 and the thermoelectric element 3 increases, and the thermoelectric element 3 may not be placed on the wiring conductor 2 with high accuracy. Because.

Furthermore, the positioning jig 6 is preferably made of a material having a thermal expansion coefficient of 5.0 × 10 ⁻⁵ / ° C. or less. This is because, when the thermal expansion coefficient of the material of the positioning jig 6 exceeds 5.0 × 10 ⁻⁵ / ° C., the positioning jig 6 is thermally expanded when the thermoelectric element 3 and the wiring conductor 2 a are heated and joined. As a result, the through-hole 7 and the thermoelectric element 3 may come into contact with each other, and the contact tends to cause scratches or peeling of the plating on the side surface of the thermoelectric element 3. Here, examples of the material of the positioning jig 6 include alumina, aluminum, copper, steel, and stainless steel. In particular, stainless steel is preferable from the viewpoints of heat resistance, workability, durability, and cost.

  Next, the manufacturing method of the thermoelectric module of this invention is demonstrated below.

  First, the support substrate 1a is prepared. As the support substrate 1a, a substrate having excellent vibration resistance and impact resistance, high adhesion strength of the wiring conductor 2a, and low thermal resistance as a heat radiating surface or a cooling surface is preferable. Specifically, a sintered body made of at least one of alumina, mullite, aluminum nitride, silicon nitride, and silicon carbide can be exemplified. In particular, from the viewpoint of cost, the alumina sintered body, the aluminum nitride sintered body from the viewpoint of high thermal conductivity and low thermal resistance, the silicon carbide sintered body from the viewpoint of strength and thermal conductivity, the impact resistance and strength of the sintered body. In this respect, a silicon nitride sintered body can be suitably used.

  The bending strength of the support substrate 1a is 200 MPa or more, particularly 250 MPa or more, and more preferably 300 MPa or more, so that damage to the support substrate 1a can be prevented even with respect to stress concentration accompanying the formation of the wiring conductor 2 and the solder layer. It is preferable in terms of enhancing the effect and obtaining higher reliability.

  Next, the wiring conductor 2a is formed on the support substrate 1a. The wiring conductor 2 can use at least one kind of metal among Cu, Al, Au, Pt, Ni and W. Of these, Cu is particularly desirable in terms of electrical conductivity and adhesion strength to the support substrate 1, and Al is desirable in terms of cost.

  The wiring conductor 2 may be formed, for example, by applying a metal paste to the surface of the green sheet to be the support substrate 1a and simultaneously firing, or by preparing the support substrate 1a and then applying and baking the metal paste. Producing by plating on the metallized surface is preferable in terms of cost and accuracy of electrode shape.

  Next, solder paste 8 or a bonding agent made of solder paste is applied to at least a part of the wiring conductor 2 on the support substrate 1a to form a solder layer. The solder paste 8 preferably contains a Sn component in order to increase the bonding strength. Specifically, Sn-Sb or Au-Sn can be exemplified. In particular, Au—Sn is a eutectic alloy, which is preferable in terms of good fluidity and wettability and high bonding strength. Here, as a coating method, a screen printing method using a metal mask or a screen mesh is preferable in terms of cost and mass productivity.

  Next, a positioning jig 6 having a plurality of openings 5 is prepared. When a plurality of positioning jigs 6 having such a plurality of openings 5 are stacked and the openings 5 are shifted from each other, a through-hole 7 that is an insertion site of the thermoelectric element 3 is formed by overlapping the openings 5. In order to form the through hole 7, at least two positioning jigs 6 are required. Here, in order to stack the positioning jigs 6 and make the through holes 7 square and rectangular, for example, as shown in FIG. The two openings 5 may be positioned diagonally. Any material can be used for the positioning jig 6 as long as it can withstand the heating process (about 300 ° C.) of the thermoelectric module, but stainless steel is the best in terms of heat resistance, workability, durability, and cost.

  Further, as a processing method for manufacturing the opening 5 of the positioning jig 6, it is preferable to manufacture by an exposure process in which a mask is applied and etching is performed. In particular, as the processing accuracy of the opening 5, if a variation with respect to the length of the opening 5 is ± 10% or less, preferably ± 5% or less, more desirably ± 3% or less, a plurality of positioning jigs 6 are stacked. It is preferable when the accuracy of the through-hole 7 obtained at times is increased and the thermoelectric element 3 is accurately arranged on the wiring conductor 2a.

  Next, as shown in FIG. 3, after positioning the through-hole 7 formed from the opening 5 of the laminated jig 6 positioned above the wiring conductor 2a on which the thermoelectric element 3 is arranged, the laminated lamination is performed. A plurality of positioning jigs 6 are supported by forming through holes penetrating the jig 6 and inserting pins 10 into the through holes.

  Next, the support substrate 1a is held by the jig base 11, the jig base 11 at a position corresponding to the through hole of the positioning jig 6 is drilled, and the pin 10 inserted into the through hole is inserted into the jig. The thermoelectric element 3 is positioned and fixed by fixing the positioning jig 6 to the base 11. Here, the jig base 11 may have the pins 10 fixed in advance at the same positions as the through holes of the positioning jig 6, but the pins 10 are inserted at positions corresponding to the through holes of the positioning jig 6. Therefore, it is more preferable from the viewpoint of processing cost that the positioning jig 6 can be stacked more easily. If the number of pins 10 is two or more, preferably three, and more preferably four, the accuracy of the through-hole 7 obtained when a plurality of positioning jigs 6 are stacked is increased, and the thermoelectric element 5 is fixed. It is preferable when arranging on the wiring conductor 2a with high accuracy. Further, it is preferable to sandwich a spacer or the like so that the solder paste 8 and the positioning jig 6 do not come into contact with each other.

  Next, the thermoelectric element 3 is inserted into the through hole 7. As a method of inserting the thermoelectric elements 3, the thermoelectric elements 3 may be picked up and inserted one by one with vacuum tweezers or the like. However, for mass productivity, after the thermoelectric elements 3 are collectively transferred to the transfer jig, the through holes 7 are inserted. A method of transferring to is preferable.

  According to the present invention, after the thermoelectric element 3 is positioned, it is important to perform heat bonding with the wiring conductor 2a via solder. The heat bonding may be performed by rapidly heating to the solder melting temperature, but using the flux component contained in the solder paste 8 or the like, the heat bonding is performed to about 100 ° C., and the thermoelectric element 3 and the wiring conductor 2a. The method of adhering may be used.

  After the heat bonding, as shown in FIG. 3B, the pins 10 that support the positioning jig 6 and the jig base 11 are removed, the plurality of positioning jigs 6 are moved, and the through holes 7 are moved to the thermoelectric elements. 3 is removed from the thermoelectric element 3 after being sufficiently expanded from the outer periphery of the thermoelectric element 3. This makes it very easy to remove the positioning jig 6 without bringing it into contact with the thermoelectric element 3.

The thermoelectric element 3 used in the present invention preferably contains at least two of Bi, Sb, Te and Se as main components. The thermoelectric element 3 using a chalcogenite type crystal such as Bi ₂ Te ₃ , Sb ₂ Te ₃ , Bi ₂ Se ₃ is excellent in thermoelectric properties near room temperature, and can be suitably used as a cooling thermoelectric module related to information communication. Moreover, these materials are also rich in reactivity with Sn, and particularly when combined with Au—Sn solder, strong adhesion is possible because of good fluidity and wettability.

  The N-type thermoelectric element 3a preferably contains I and / or Br. That is, in order to form a semiconductor, the electron concentration is adjusted by addition of a halogen element, and excellent characteristics can be exhibited as the N-type thermoelectric element 3a having a controlled carrier concentration.

  The N-type thermoelectric element 3a and the P-type thermoelectric element 3b may be a melted material or a sintered body, but the N-type thermoelectric element 3a is made of a melted material, particularly a single crystal, and is a P-type. It is excellent that the thermoelectric element 3b is made of a sintered body, particularly a sintered body having an average crystal grain size of 5 μm or less, or the N-type thermoelectric element 3a and the P-type thermoelectric element 3b are made of a melted material, particularly a single crystal. It is preferable in terms of easy realization of characteristics and cost reduction at the same time.

  Furthermore, both end surfaces of the thermoelectric element 3 are formed with two nickel plating layers and 1 in order to improve the wettability of the solder and to suppress the diffusion of the solder components constituting the solder layer into the thermoelectric element 3. An Au plating layer is provided.

  After taking out the positioning jig 6 from the thermoelectric element 3, the wiring conductor 2b and the solder paste 8 similar to the support substrate 1a are arranged on the support substrate 1b made of the same material as the support substrate 1a, and in an inert gas atmosphere. Then, the other end face of the thermoelectric element 3 that is not bonded to the support substrate 1a and the support substrate 1b are heated and bonded, so that the thermoelectric module manufactured by the method for manufacturing a thermoelectric module of the present invention is obtained.

  The thermoelectric module shown in FIG. 1 was produced using the production method of the present invention.

  First, an alumina sintered body having a relative density of 96%, a bending strength of 350 MPa, and a thermal conductivity of 24 W / mK (20 ° C.) was processed into a length of 8.2 mm, a width of 6.0 mm, and a height of 0.3 mm. Wiring conductors 2a and 2b made of Cu were formed on one surface of each of the supporting substrates 1a and 1b by a metallization method.

  Next, as thermoelectric element 3, N-type thermoelectric element 3a made of BiTeSe and 23 P-type thermoelectric elements 3b made of BiSbTe were prepared, each of which was 0.65 mm in length, 0.65 mm in width, The height was 0.90 mm. Here, 0.05 to 0.1 μm of Au and 2 μm of Ni were formed by electroplating on both end portions of the thermoelectric element 3. Here, the both end surface portions of the thermoelectric element 3 are surfaces that are heat-bonded to the wiring conductors 2a and 2b.

  Next, a solder paste 8 mainly composed of Sn—Sb having a melting point of 240 ° C. was produced and applied to a part of the surface of the wiring conductor 2a formed on the surface of the support substrate 1a. As a coating method, a mesh screen was used.

  Next, a positioning jig 6 having a plurality of openings was made using stainless steel of SUS304. Each opening 5 of the positioning jig 6 is processed in an exposure process in which a mask is applied and etching is performed. In addition, through holes for inserting the pins 10 were machined in the four corners of the positioning jig 6 that does not reach the opening 5.

  Thereafter, two positioning jigs 6 are stacked above the wiring conductor 2a coated with the solder paste 8, and the openings 5 are shifted to form a through hole 7 by overlapping the openings 5. After the through hole 7 is moved to an arbitrary position where the thermoelectric element 3 is disposed, the pin 10 is passed through the through hole and fixed to the jig base 11, and the N-type thermoelectric element 3 a and the P-type thermoelectric element 3 b are electrically connected. Were inserted in series.

  Next, using the flux component contained in the solder paste 8, it heated to 100 degreeC and joined each thermoelectric element 3 and the wiring conductor 2a.

  Next, the positioning jig 6 was moved so that the through hole 7 was wider than the outer periphery of the thermoelectric element 3, and the bonded thermoelectric module was removed.

  Finally, the other end surface of the thermoelectric element 3 that is not bonded to the support substrate 1a and the support substrate 1b are heated and bonded to the other support substrate 1b in an inert gas atmosphere to produce a thermoelectric module.

  (Example 1) An energization test and a cooling test were performed on the thermoelectric module manufactured by the method for manufacturing a thermoelectric module of the present invention, and the reliability of the thermoelectric module was verified.

  Further, as a comparative example, in the manufacturing method, before the thermoelectric element and the wiring conductor are heated and bonded, the thermoelectric element is positioned and the same test as described above is performed using a thermoelectric module manufactured by horizontally moving the positioning jig. Went.

  Here, in the verification of the reliability of the thermoelectric module, 22 thermoelectric modules were produced by each manufacturing method, and an energization test was performed in which each I / O current of 2.0 (A) was turned on and off at intervals of 5 minutes. After performing 72 cycles, the thermoelectric module was placed at a temperature of −45 ° C. and 80 ° C. every 15 minutes, and a cold test was performed for 10 hours. And the thermoelectric module whose rate of change (%) of the internal resistance (Ω) of the thermoelectric module before and after the test of the energization test and the cooling test was 0.1% or less was regarded as a non-defective product.

  In the thermoelectric module manufactured in the manufacturing process of the comparative example, since the thermoelectric element 25 moves and the solder paste 24 is deposited on the side surface of the thermoelectric element 25, it becomes impossible to secure the solder paste necessary for joining to the wiring board. The element collapses or a short circuit occurs between the adjacent thermoelectric elements 3 via the solder paste 24 attached to the side surface of the thermoelectric element 25, and the change rate of the internal resistance is zero in the ten thermoelectric modules. More than 1%.

  On the other hand, since the thermoelectric module produced by the method for manufacturing a thermoelectric module of the present invention is bonded to the wiring conductor 2a after positioning the thermoelectric element 3, the bonding force between the thermoelectric element 3 and the wiring conductor 2a is increased. It was possible to prevent the solder paste 8 from being attached to the side surface of the thermoelectric element 3 and to prevent the thermoelectric element 3 from falling over, and to produce a thermoelectric module in which the adjacent thermoelectric elements 3 were not short-circuited.

(Example 2) In the positioning jig used in the method for manufacturing the thermoelectric module of the present invention, the area (S1) of the through hole 7 formed by laminating the two positioning jigs 6 is 0.427 to 0.845. (mm ²⁾ and then, the thermoelectric elements 3 and area of the end surface (S2) .4225 and (mm ²⁾ was inserted into the through holes 7, to prepare a thermoelectric module.

Here, about the obtained thermoelectric module, the external appearance of the thermoelectric element 3 was test | inspected with the binocular microscope of 40 times magnification. As an inspection method, for plating peeling, all the plated portions of the end face that are not joined to the wiring conductor 2a of the thermoelectric element 3 are inspected. Only the thermoelectric element 3 was examined. The side surface of the thermoelectric element 3 has no flaws, and the plating peeling of the end face is less than 50% of the plating area of both end faces of the thermoelectric element 3, and the plating peeling of the end face of the thermoelectric element 3 is on both end faces of the thermoelectric element 3. A case where the plating area exceeds 50% or a case where the side surface of the thermoelectric element 3 is scratched is indicated by Δ. Further, after the thermoelectric element 3 and the wiring conductor 2a are heat-bonded, the positional accuracy of the thermoelectric element 3 with respect to the wiring conductor 2a is inspected, and the thermoelectric element 3 is placed in the wiring conductor 2a. Those overhanging from the conductor 2a were evaluated as Δ, and the results are shown in Table 1.

  As shown in Table 1, since Sample Nos. 1 and 2 were less than S1 / S2 = 1.05, it was difficult to insert the thermoelectric element 3 into the through hole 7 before heat bonding, and the thermoelectric element 3 became a through hole. Scratches and peeling of the plating occurred in contact with 7.

  Moreover, since the sample numbers 6 and 7 exceeded S1 / S2 = 1.90, it was difficult to position the thermoelectric element 3, and the thermoelectric element 3 could not be arranged on the wiring conductor 2a with high accuracy.

  On the other hand, since sample numbers 3 to 5 are set to S1 / S2 = 1.05 to 1.90, the thermoelectric element 3 can be easily inserted into the through hole 7 and the thermoelectric element 3 is disposed at an appropriate position. I was able to.

  (Embodiment 3) In a positioning jig used in the method for manufacturing a thermoelectric module of the present invention, a positioning jig 6 that does not have a curved surface at the corner of the opening 5, and a curved surface 9 at the corner of the opening 5, Then, a thermoelectric module was manufactured using the positioning jig 6 in which the radius of curvature of the curved surface portion 9 was changed with the longest side of the opening 5 as a reference.

Here, about the obtained thermoelectric module, the external appearance of the thermoelectric element 3 was test | inspected with the binocular microscope of 40 times magnification. The inspection method is the same as in Example 2. The side surface of the thermoelectric element 3 is not scratched, and the end surface of the thermoelectric element 3 that is not joined to the wiring conductor 2a has no plating peeling. The plating peeling of the plated portion of the end face is the plating area of both end faces of the thermoelectric element 3. Of 50% or less of the thermoelectric element 3, the plating peeling of the end face of the thermoelectric element 3 exceeds 50% of the plating area of the both end faces of the thermoelectric element 3, or the side face of the thermoelectric element 3 is marked with △, The positional accuracy of the element 3 was evaluated in the same manner as in Example 2, and the results are shown in Table 2.

  As shown in Table 2, in Sample No. 8, since the curved surface portion 9 was not applied to the corner portion of the opening 5, the thermoelectric element 3 contacted the corner portion of the through hole 7, and plating peeling occurred.

  In Sample Nos. 13 and 14, since the curved surface portion 9 exceeds 50% of the longest side of the opening 5, the clearance between the through hole 7 and the thermoelectric element 3 is increased, and the thermoelectric element 3 is arranged on the wiring conductor 2a with high accuracy. I couldn't.

  On the other hand, in Sample Nos. 9 to 12, since the curved surface portion 9 is applied to the corner portion of the opening 5 and the radius of curvature of the curved surface portion 9 is 50% or less of the longest side of the opening 5, the plating is peeled off from the thermoelectric element 3. Thus, the thermoelectric element 3 could be placed on the wiring conductor 2a at an appropriate position with high accuracy.

(Example 4) In the positioning jig used in the method for manufacturing a thermoelectric module of the present invention, a thermoelectric module was manufactured using a positioning jig 6 made of a material having a different coefficient of thermal expansion. Here, about the obtained thermoelectric module, the external appearance of the thermoelectric element 3 was test | inspected with the binocular microscope of 40 times magnification. The inspection and evaluation method is the same as in Example 3. The results are shown in Table 3.

As shown in Table 3, since the thermal expansion coefficient of the material of the positioning jig 6 exceeds 5.0 × 10 ⁻⁵ / ° C. for the sample numbers 20 and 21, the thermoelectric element 3 and the wiring conductor 2a are heat bonded. , The thermal expansion of the positioning jig 6 is remarkably increased, the clearance between the thermoelectric element 3 and the through hole 7 is decreased, the through hole 7 is in contact with the side surface of the thermoelectric element 3, and plating peeling occurs on the thermoelectric element 3. .

On the other hand, sample numbers 15 to 19 have a thermal expansion coefficient of 5.0 × 10 ⁻⁵ / ° C. or lower because the material of the positioning jig 6 has a thermal expansion coefficient of 5.0 × 10 ⁻⁵ / ° C. or less. Since the thermal expansion of the positioning jig 6 was suppressed and contact between the thermoelectric element 3 and the through-hole 7 could be prevented, a thermoelectric module composed of the thermoelectric element 3 free from scratches and plating peeling could be produced.

It is a perspective view which shows the thermoelectric module produced with the manufacturing method of the thermoelectric module of this invention. (A) is a plan view of a positioning jig, (b) is a plan view showing an opening in which a plurality of positioning jigs are stacked, (c) is a plan view in which a thermoelectric element is inserted into a through hole, (D) is a top view which shows opening of the positioning jig which has a curved-surface part in a corner | angular part. It is a fragmentary sectional view which shows an example of the manufacturing method of the thermoelectric module of this invention. It is a fragmentary sectional view which shows the manufacturing method of the conventional thermoelectric module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,22 ... Support substrate 2, 21 ... Wiring conductor 3, 25 ... Thermoelectric element 4 ... Lead wire 5 ... Opening 6, 23 ... Grid-shaped jig 7 ... Through Hole 8, 24 ... Solder paste (solder layer)
9 ... curved surface part 10 ... pin 11 ... jig base

Claims (6)

A wiring conductor is arranged on the support substrate, a plurality of positioning jigs having a plurality of openings are stacked above the wiring conductor, and the openings are shifted from each other. A thermoelectric element including a step of inserting a thermoelectric element into the through-hole, heat-bonding the thermoelectric element to the wiring conductor, moving the positioning jig, and removing the positioning jig from the thermoelectric element. Module manufacturing method. The method of manufacturing a thermoelectric module according to claim 1, wherein the plurality of positioning jigs move in a horizontal direction with respect to the support substrate. The positioning jig has a lattice shape, and when the area of the through hole is S1 and the area of the end face of the thermoelectric element is S2, S1 / S2 = 1.05 to 1.90. Item 3. A method for manufacturing a thermoelectric module according to Item 1 or 2. The positioning jig used in the manufacturing method according to claim 1, wherein a curved surface portion is formed at a corner of the opening. The positioning jig according to claim 4, wherein a radius of curvature of the curved surface portion is 50% or less of a longest side length of the opening. The positioning jig according to claim 4, wherein the positioning jig is made of a material having a thermal expansion coefficient of 5.0 × 10 ⁻⁵ / ° C. or less.

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