JPH0951125A - Method for manufacturing thermoelectric conversion device - Google Patents

Abstract

(57) [Abstract] (Correction) [PROBLEMS] To provide a method for manufacturing a thermoelectric conversion device that can simplify the assembly process of the thermoelectric conversion device and reduce the processing cost. SOLUTION: Resist masks 5a and 5b having an electrode pattern are formed on one surface of a copper plate 4 which is an electrode base material, and then a peelable separator 25 is attached to one surface of the surface opposite to the surface where the resist mask is formed. The adhesive surface on the other side of the double-sided adhesive tape 6 is attached and etched to form a first electrode plate 2a and a second electrode plate 2b, which are two types of upper and lower electrode patterns, at once. Next, the first and second electrode plates attached to the tape 6 are electrolessly nickel-plated, and solder printing 8 is applied to each, and the P-type semiconductor element 1a and the N-type semiconductor element 1b are attached to the second electrode plate 2b. After alternately arranging, the first electrode plates 2a are placed thereon, and the tape 6 is adhered to the tape 6 for reflow soldering. Finally, the first and second electrode plates 2a and 2b are peeled off from the separator 25 of the tape 6 and directly attached to the heat exchanger for thermal connection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoelectric conversion device applicable to a cooling device, a heating device, a temperature control device having both cooling and heating devices, a power generation device utilizing the temperature difference between the cooling and heating devices, and the like. The present invention relates to a method of manufacturing a device.

[0002]

2. Description of the Related Art The basic structure of a thermoelectric converter is shown in FIG.
Will be described with reference to. The thermoelectric conversion device 3 arranges a plurality of P-type semiconductor elements 1a and N-type semiconductor elements 1b for thermoelectric conversion alternately at fixed intervals, and on the one side of the P-type semiconductor element 1a and the N-type semiconductor element 1b, respectively. Electrode plates 2a and 2b are provided between the upper surfaces of adjacent semiconductor devices of opposite polarity and on the lower surface of adjacent semiconductor devices of opposite polarity on the other side, and solder 21 and the like are provided between the electrode plates 2a and 2b and the semiconductor device, respectively. And the P-type semiconductor element 1a and the N-type semiconductor element 1b are alternately and electrically connected in series. Further, the semiconductor element rows thus connected are sandwiched from above and below by a substrate 22 having an electrical insulation property and supported and fixed.

When a voltage is applied from the DC power source 23 to the two ends connected in series in this way, the Peltier effect causes an endothermic action in the heat exchanger 9a on the upper surface side of the thermoelectric converter 3,
The heat is carried from the thermoelectric converter 3 to the heat exchanger 9b on the lower surface side. The heat absorption amount and the heat amount corresponding to the electric input are radiated by the heat exchanger 9b on the lower surface side of the thermoelectric conversion device 3. Therefore, when the heat of the heat exchanger 9b is efficiently dissipated, the heat continuously moves from the heat exchanger 9a to the heat exchanger 9b.

Therefore, the heat exchangers 9a and 9b need to suppress the thermal resistance, and from this necessity, the heat exchangers 9a and 9b come into contact with the thermoelectric conversion device 3 through the heat conductive grease 16 or the like. are doing. Further, as the material of the heat exchangers 9a and 9b, a metal material such as an aluminum extruded material with fins is used.

A plurality of P-type semiconductor elements 1a and N-type semiconductor elements 1b are alternately arranged at regular intervals and adjacent P-type semiconductor elements 1a are arranged.
Type / N type pair of semiconductor elements 1a and 1b which are commonly joined to the first surface of the first electrode plate 2a and which are not commonly joined on the first side Second of the element
By commonly bonding the second electrode plate 2b to the surface of
A thermoelectric conversion device 3 in which a P-type semiconductor element 1a and an N-type semiconductor element 1b are alternately connected in series is disclosed in, for example, Japanese Patent Laid-Open No. 58-1.
It is well known in Japanese Patent Publication No. 99578 and Japanese Utility Model Laid-Open No. 63-20465.

As a conventional technique in the process of assembling the thermoelectric conversion device 3, for example, a single electrode plate is arranged on a ceramic substrate by an assembling jig or the like as described in Japanese Patent Laid-Open No. 58-1995578. How to do it, Shokai 63-204
DB in which a copper plate is directly baked on a ceramic substrate and then etching / plating is performed as disclosed in Japanese Patent Laid-Open No. 65
There is a method of using a C (direct bonding copper) substrate. By the way, as a conventional technique for etching on the tape, but not in the process of assembling the thermoelectric conversion device 3, etching and plating of a copper foil attached using a tape for TAB (tape automated bonding) used in the process of assembling a semiconductor LSI. There is processing.

[0007]

However, although the above method using the DBC substrate can simplify the arrangement of the electrode plates, it not only increases the cost of the substrate but also the cost of incidental equipment such as molds and jigs. Will be needed. Further, since the ceramic substrate has a thickness of about 0.6 to 0.8 mm, the characteristics are deteriorated due to thermal resistance.

The above TA using a chemical resistant adhesive
The tape for B (Tape Automated Bonding) is incorporated in the semiconductor LSI as it is, but it does not have high thermal conductivity, so it was not suitable for the purpose of heat bonding to the heat exchanger as it is.

When it is attached to a heat conductive adhesive tape and subjected to etching / plating, the etched portion is exposed to a chemical such as an etching liquid or a plating liquid by exposing the adhesive layer of the adhesive tape. Since the heat conductive adhesive tape that is not made for etching use does not have chemical resistance, the adhesive changes its properties by being exposed to the etching liquid chemical in the etching process, and the etching liquid chemical remains on the adhesive. Influences other materials over time (such as corrosion)
Is also concerned. Therefore, there is also a method of applying a solid resist mask to the surface of the copper plate on which the adhesive tape is attached, but this resist mask cannot be removed later, which causes thermal resistance of the bonding surface and causes deterioration of characteristics.

If a resist mask is applied to the surface of the copper plate to which the adhesive tape is attached as a barrier property against chemicals, it is effective as a barrier against chemicals during etching. However, since the resist mask portion cannot be plated as it is after the etching process, it is necessary to wash and remove the resist mask on the surface of the copper plate before the plating step. At this time, the resist mask on the surface of the copper plate on which the adhesive tape is attached is also removed, and the barrier property against chemicals is lost during plating.

A plurality of electrode plates are usually taken like an IC lead frame in order to improve production efficiency. However, in order to cut and divide on an adhesive tape after the assembly process, a space for cutting is cut at a cut portion. Is required, the yield (the number of products) is reduced, and a dedicated cutting device is also required. On the other hand, if the adhesive tape is cut before the assembly process, it becomes difficult to take a plurality of tapes.

Since the heat conductive adhesive tape can be directly attached to the heat exchanger, the process is simplified and the workability is improved. However, since the adhesive tape requires electrical insulation (DC current flows through the electrode plate), its thermal conductivity is limited, and if the thickness is reduced to reduce the thermal resistance, the workability of attachment deteriorates. However, there is a limit in reducing the thickness itself.

An object of the present invention is to solve the above problems, and to provide a method of manufacturing a thermoelectric conversion device which can simplify the assembly process of the thermoelectric conversion device and reduce the processing cost. is there. Another object of the present invention is to provide a method for manufacturing a thermoelectric conversion device which has an excellent barrier property against chemicals during etching and plating. Further, the object of the present invention is to
It is an object of the present invention to provide a method for manufacturing a thermoelectric conversion device that can simplify the taking of a plurality of devices. Still another object of the present invention is to provide a method for manufacturing a thermoelectric conversion device that can improve heat exchange performance.

[0014]

SUMMARY OF THE INVENTION According to the present invention, a plurality of P-type semiconductor elements and N-type semiconductor elements are alternately arranged at regular intervals, and a pair of adjacent P-type and N-type semiconductor elements are provided. The first electrode plate is commonly bonded to the surface of the first electrode plate, and the second electrode plate is commonly connected to the second surface of the pair of adjacent P-type / N-type semiconductor elements that are not commonly bonded to the first surface. By joining
In a method of manufacturing a thermoelectric conversion device in which P-type semiconductor elements and N-type semiconductor elements are alternately connected in series, instead of arranging the first and second electrode plates one by one, a copper plate that is an electrode base material is used. A resist mask having an electrode pattern is formed by photo-etching or the like, and then, on the opposite surface of the copper plate to the surface on which the resist mask is formed, an adhesive surface on the other surface of the double-sided adhesive tape 6 having a peelable separator 25 attached on one surface. By attaching and etching, the first electrode plate and the second electrode plate, which are two types of upper and lower electrode patterns, are collectively made without arranging. Next, the arrayed first and second electrode plates attached to the double-sided adhesive tape are directly electroless nickel plated. Next, solder-printing is performed on each of the plated first and second electrode plates attached to the double-sided adhesive tape, and P-type semiconductor elements and N-type semiconductor elements are alternately arranged on the second electrode plate. Reflow solder bonding is performed with the first electrode plate placed on the double-sided adhesive tape. Finally, the separator of the double-sided adhesive tape to which the first and second electrode plates are attached is peeled off, and the separator is attached directly to the heat exchanger for thermal connection.

In this case, the electrode plate array pattern can be formed on the double-sided adhesive tape by etching and plating the array pattern of the electrode plate with the copper plate attached to the double-sided adhesive tape. A thermoelectric conversion device can be assembled on a double-sided adhesive tape by solder paste printing on a plate, alternate mounting of P-type / N-type semiconductor elements by a chip mounter, or reflow soldering.

As the double-sided adhesive tape to be attached to the copper plate prior to the above etching process, one having both solder heat resistance and thermal conductivity is used. As a result, the double-sided adhesive tape can be thermally bonded to the heat exchanger without being peeled off.

In the electrode pattern of the resist mask formed on the copper plate which is the electrode base material, a resist mask having a pattern reversible with the resist mask pattern on the etched surface side of the copper plate is formed on the non-etched surface side of the copper plate. , A double-sided resist mask is used.
As a result, after the etched portion of the copper plate is removed, the adhesive surface of the double-sided adhesive tape is covered and protected by the resist mask on the non-etched surface side, so that the double-sided adhesive tape has an excellent barrier property against etching liquid chemicals.

In the resist mask formed on the copper plate which is the electrode base material, the resist mask on the non-etched surface side of the copper plate to which the double-sided adhesive tape is attached is not a resist agent for etching but a resist for plating or soldering. Use agents. As a result, when the resist mask on the etched surface side of the copper plate is removed after etching processing, the resist mask on the non-etched surface side can be left without being removed, and the double-sided adhesive tape has an excellent barrier property against plating liquid chemicals.

In order to obtain a plurality of electrode patterns on the double-sided adhesive tape, the double-sided adhesive tape is temporarily cut into a plurality of electrode pattern outer dimensions by Thomson processing or the like to remove unnecessary portions other than the electrode patterns. Then, a solder heat-resistant masking tape or the like is attached again to form a two-layer integrated tape.

In order to achieve higher thermal conductivity than the above double-sided adhesive tape, another thermal conductive grease, such as silicone adhesive or epoxy adhesive, which can be easily peeled off after reflow soldering and has higher thermal conductivity, is used. As the double-sided pressure-sensitive adhesive tape, a heat-peelable tape having a function of lowering the pressure-sensitive adhesive force is used so that the materials can be thermally bonded.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) A first embodiment of a method for manufacturing a thermoelectric conversion device according to the present invention will be described with reference to FIGS. 1A to 1E show the manufacturing process sequence. First, as shown in FIG. 1 (A), the adhesive surface of the other surface of the double-sided adhesive tape 6 having the separable separator 25 attached to one surface thereof is attached to the back surface side of the copper plate 4. On the surface side of the copper plate 4, a resist mask 5a having a first electrode plate pattern corresponding to the array of the first electrode plates 2a illustrated in FIG. 2 (corresponding to the array of the second electrode plates 2b illustrated in FIG. 3). In the case of the second electrode plate pattern to be performed, the reference numeral 5b) is applied. As the double-sided adhesive tape 6, for example, a tape having both solder heat resistance and thermal conductivity, such as Sumitomo 3M tape 9885, is used.

Then, etching processing is performed as shown in FIG. Then, the resist mask 5a of the copper plate 4
・ The part not covered with 5b is dissolved and removed. Then, as shown in (C) of FIG.
After removing and cleaning b, electroless nickel plating is performed to form a nickel film 24 on the surface of the copper plate 4. Next, solder printing 8 is applied on the nickel films 24 of the first electrode plate 2a and the second electrode plate 2b thus obtained, respectively, and the first electrode is formed as shown in FIG. A P-type semiconductor element 1a is mounted on the board 2a by soldering on the solder print 8
And N-type semiconductor elements 1b are arranged alternately. Next, as shown in (E) of the same figure, the second electrode plate 2b is combined with the first electrode plate 2a in which the P-type semiconductor element 1a and the N-type semiconductor element 1b are arranged and pressed down, and reflow soldering is performed. Finally, the separator 25 of the double-sided adhesive tape 6 is peeled off, and directly attached to the heat exchangers 9a and 9b as shown in FIG.

(Second Embodiment) FIGS. 4 to 6 show a second embodiment of the present invention. As shown in FIG. 4, a resist mask 5a (5b) is applied to the etching surface side, which is the surface of the copper plate 4, with a resist agent 12a for etching the electrode pattern, and the adhesive tape attaching surface side of the copper plate 4 is provided with the above electrode. A resist mask 18a (18b) is formed by plating a reversible electrode pattern with the pattern or using a solder resist agent 12b. In this case, as shown in FIG. 5, after the etched portion of the copper plate 4 is removed, the adhesive surface of the double-sided adhesive tape 6 is covered and protected by the reversible resist mask 18a (18b), so that the etching process is performed. It is possible to prevent the adhesive surface from being affected by the etching liquid chemicals.
Next, as shown in FIG. 6, the resist mask 5a (5b) for etching the surface of the copper plate 4 is washed and removed before the plating step. At this time, the resist mask 18a (18b) formed by the resist agent 12b for plating or soldering is used. Remains without being removed by the cleaning agent of the resist mask 5a (5b), so the adhesive surface of the adhesive tape is covered and protected during plating. Since the resist mask 18a (18b) is not present at the joint between the copper plate 4 and the double-sided adhesive tape 6, there is no concern that the resist mask 18a (18b) will affect the thermal resistance. Other configurations are similar to those in the first embodiment.

(Third Embodiment) FIGS. 7 and 8 show a third embodiment of the present invention. As shown in FIG. 7, in order to obtain a plurality of electrode patterns on the double-sided adhesive tape 6, the double-sided adhesive tape 6 is temporarily cut into a plurality of electrode pattern outer dimensions by Thomson processing or the like, and other than the electrode pattern. The unnecessary portion 13 of is removed. Then, as shown in FIG. 8, a masking tape 14 having solder heat resistance and the like are attached thereto to form an integrated tape 15, and the separator 25 of the double-sided adhesive tape 6 is peeled off and attached to the copper plate 4. At this time, the copper plate 4 has been subjected to the double-sided resist mask processing, and the resist mask 18a (18) having a reversible electrode pattern with the electrode pattern on the side of the previous etching surface is formed.
The b) side is aligned and attached to the integrated tape 15. Other configurations are the same as those in the second embodiment.

(Fourth Embodiment) FIGS. 9 and 10 show a fourth embodiment of the present invention. In order to achieve higher heat conductivity than the double-sided adhesive tape 6, another heat conductive grease 16 having higher heat conductivity can be easily peeled off after reflow soldering.
As the double-sided pressure-sensitive adhesive tape 6, a heat-peelable tape 17 having a function of significantly lowering the pressure-sensitive adhesive force when heated is used so that it can be thermally bonded with a material such as (see FIG. 11). Such a heat-peelable tape 17 can be easily peeled off after soldering, and enables heat bonding to the heat exchangers 9a and 9b with a heat conductive grease 16 or the like with further suppressed thermal resistance.
Other configurations are similar to those in the first embodiment.

[0026]

As described above, according to the present invention of claim 1, in an efficient skeleton structure thermoelectric conversion device using only a semiconductor element and an electrode plate that does not use an insulating substrate, the electrode plate assembling step is performed. It is omitted, and the cost of incidental equipment such as molds and jigs is also unnecessary, and the processing cost can be reduced.

According to the second aspect of the present invention, it is possible to easily prevent the influence of the chemical during etching on the adhesive surface of the double-sided adhesive tape.

According to the present invention of claim 3, since it is possible to prevent the influence of chemicals at the time of etching or plating on the adhesive surface of the double-sided adhesive tape, it is not necessary to develop a new tape having chemical resistance, and only that is implemented. It's easy.

According to the present invention according to claim 4, it is not necessary to cut the double-sided adhesive tape by post-processing to take a plurality of tapes, and a plurality of tapes can be prepared without preparing a dedicated tape cutting jig. The thermoelectric conversion device can be easily assembled and separated.

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram of a thermoelectric conversion device according to a first embodiment.

FIG. 2 is a plan view of an array pattern of first electrode plates of the thermoelectric conversion device according to the first embodiment.

FIG. 3 is a plan view of an array pattern of second electrode plates of the thermoelectric conversion device of the first embodiment.

FIG. 4 is a process diagram of forming a resist mask of the thermoelectric conversion device according to the second embodiment.

FIG. 5 is an etching process diagram of the thermoelectric conversion device according to the second embodiment.

FIG. 6 is a resist mask removal process diagram of the thermoelectric conversion device according to the second embodiment.

FIG. 7 is a cross-sectional view of a copper plate of a thermoelectric conversion device according to a third embodiment.

FIG. 8 is a cross-sectional view of an etching tape of a thermoelectric conversion device according to a third embodiment.

FIG. 9 is a structural diagram of a thermoelectric conversion device of Embodiment 4 using a heat-peelable tape.

FIG. 10 is a cross-sectional view showing an example of assembling the thermoelectric conversion device of Embodiment 4 using a heat-peelable tape.

FIG. 11 is a basic structural diagram of a conventional thermoelectric conversion device.

[Explanation of symbols]

1a P-type semiconductor element 1b N-type semiconductor element 2a First electrode plate 2b Second electrode plate 3 Thermoelectric converter 4 Copper plate 5a Resist mask (for first electrode plate) 5b Resist mask (for second electrode plate) 6 Double-sided adhesive tape 8 Solder printing 9a Heat exchanger (heat absorption side) 9b Heat exchanger (heat radiation side) 12a Etching resist agent 12b Metallic resist agent 13 Unnecessary parts other than electrolytic pattern 14 Solder heat resistance masking Tape 15 Integrated tape 16 Thermally conductive grease 17 Thermally peelable tape 18a Reversible resist mask (for first electrode plate) 18b Reversible resist mask (for second electrode plate) 24 Nickel film

Claims (4)

[Claims] 1. A plurality of P-type semiconductor elements and N-type semiconductor elements are alternately arranged at a constant interval, and adjacent P-type and N-type semiconductor elements are arranged.
A first electrode plate is commonly bonded to the first surfaces of the pair of semiconductor elements, and adjacent P electrodes that are not commonly bonded to the first surfaces
A method for manufacturing a thermoelectric conversion device, in which a P-type semiconductor element and an N-type semiconductor element are alternately connected in series by joining a second electrode plate commonly to the second surfaces of a pair of N-type and N-type semiconductor elements Of a double-sided adhesive tape in which a resist mask of an electrode pattern is formed on one surface of a copper plate which is an electrode substrate, and then a peelable separator is attached to one surface of the copper plate on the side opposite to the surface where the resist mask is formed. A step of collectively forming a first electrode plate and a second electrode plate, which are two types of upper and lower electrode patterns, by pasting the adhesive surface on the other side and performing an etching process, and then pasting on the double-sided adhesive tape The step of directly electroless nickel-plating the attached first and second electrode plates, and then solder-printing the first and second electrode plates attached to the double-sided adhesive tape to form the second electrode. P type on the plate After alternately arranging the conductor element and the N-type semiconductor element, the first electrode plate is placed on the conductor element and the N-type semiconductor element is adhered to the double-sided adhesive tape to perform reflow soldering, and finally, the first and second A method for manufacturing a thermoelectric conversion device, comprising the steps of peeling off the separators of the double-sided adhesive tape attached to these electrode plates and directly attaching them to the heat exchanger for thermal connection. 2. The method for manufacturing a thermoelectric conversion device according to claim 1, wherein a resist mask having a pattern reversible to the pattern of the resist mask formed on the etched surface side of the copper plate is formed on the non-etched surface side of the copper plate. 3. The thermoelectric generator according to claim 2, wherein the resist mask on the side of the copper plate 4 to be etched is formed of a resist agent for etching, and the resist mask on the side of the non-etched side of the copper plate is formed of a resist agent for plating or soldering. Method of manufacturing converter. 4. In order to obtain a plurality of electrode patterns on a double-sided adhesive tape, the double-sided adhesive tape is temporarily cut into a plurality of electrode pattern outer dimensions by Thomson processing or the like to remove unnecessary portions other than the electrode pattern. The method for manufacturing a thermoelectric conversion device according to claim 1, wherein the thermoelectric conversion device is removed, and a soldering heat-resistant masking tape is attached again from above to form an integrated tape.