JP2001168368A - Terminal box - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a terminal box which can maintain the heat radiating property of a bypass diode while securing a specified diode capacity under a high temperature environment. SOLUTION: A thin bare chip 2 is used as a bypass diode. The bare chip 2 is held between overlapping parts 31 of a set of two conductive metal thin plates fastened to respective relay terminals and extended between these relay terminals in such a manner as to face each other, to form a bypass circuit structure 7. When supplying a specified necessary amount of current to the bypass circuit, a cross-sectional area of each conductive metal thin plate and a joint area of each conductive metal thin plate with a corresponding electrode layer are so set that the surface temperature of the bare chip with the following changes in temperature considered may be the thermal destruction temperature or below: the temperature change elements include at least (A) a change of the ambient temperature of the bare chip based on the influence by the sun beam, the temperatures of roof tiles or the like, (B) the increase in temperature of the bare chip itself based on the generation of heat by conduction, and (C) the decrease in heat radiation temperature of the bare chip based on the thermal conduction through the conductive metal thin plates joined to the upper and lower electrode layers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal box constituting an output section of a solar cell module suitable for a solar power generation system.

[0002]

2. Description of the Related Art A photovoltaic power generation system which has been widely used in recent years is composed of a plurality of solar cell modules arranged and arranged on a roof of a house or the like. As shown in FIG. Are serially connected to each other via the back side output unit 110, and each of the solar cell modules located at the beginning and end of the series connection is connected to a lead-in cable 140, 140 extending indoors, respectively. A general system is a system in which a large number of units are provided in series, connected to a commercial power system through an indoor inverter, and supplied to indoor electric wiring.

[0003] As a solar cell module 100, FIG.
As shown in FIG. 8, a solar cell 120, a support 130 supporting the solar cell, a terminal box 101 constituting an output unit 110 provided on the back side of the solar cell 120, and polarities extending from the terminal box. There are two different output cables 106, 106. Each output cable 106 is inserted into the insertion groove 130a of the support 130.
Further, by extending to the eaves side and the ridge side through the insertion groove of the ridge side module (not shown), it is connected to the output part of another adjacent module or the above-described lead-in cable 140.

[0004] The terminal box 101 constituting the output section of these solar cell modules is disclosed in Japanese Patent Application Laid-Open No. H11-026035.
For example, as disclosed in Japanese Patent Application Publication No. H10-209, the internal structure shown in FIG. 19 is provided.

[0005] That is, at a predetermined portion of the bottom wall 152 abutting on the back surface of the solar cell, an insertion opening 105a for inserting an output extraction electrode material protruding from the back surface of the solar cell.
Inside the box-shaped housing 105 provided with the two relay terminals 10
4, 104 are arranged symmetrically, and the output cable 106 extending to the outside of the housing is provided at the base end side of each relay terminal 104.
Is connected. A bypass diode 102 is connected between the relay terminals 104, 104, and a reverse current flows into the module when a part of a plurality of cells constituting a solar cell is shaded or at night. , A bypass circuit is configured to prevent the occurrence of such a situation.

[0006]

By the way, the relay terminal 1
04, 104 connected between the bypass diode 102
Conventionally, a general-purpose diode packaged by resin sealing is used, and a specific connection form with the relay terminal 104 is a conductive thin wire wire-bonded to an electrode layer of the diode in the packaging. And through a lead wire 121 connected to the relay terminal 104 and directly soldered to the relay terminal 104. However, on the back side of the solar cell module installed on the roof of a house or the like, day and night, season, etc. The temperature difference due to the change is as large as about -40 ° C to 90 ° C,
In a daytime in summer, the environment becomes a high temperature environment exceeding 80 ° C. Therefore, in the bypass diode having the above connection form, the heat generated in the diode cannot be sufficiently dissipated through the fine wires and the lead wires. However, there is a problem that not only the expected characteristics of the diode are not ensured, the required bypass function is not exhibited, but also the diode is disconnected or broken by the increased heat energy.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a terminal box in which the heat dissipation of a bypass diode is maintained and a predetermined diode capacity is ensured even in a high temperature environment.

[0008]

The inventor of the present invention has made intensive studies to solve the above-mentioned problems. As a result, the bypass diode of the thin bare chip is sandwiched between the conductive metal thin plates, so that the bare chip and the bare chip can be connected to each other. A sufficient contact area is maintained between the conductive metal sheet and the heat generated in the bare chip is quickly radiated through the conductive metal sheet, and the cross-sectional area of the conductive metal sheet and the contact area are appropriately set. As a result, it has been found that a predetermined required amount of current can be supplied to the bare chip even in a high-temperature environment such as summer, and the bypass function can be reliably maintained, and the present invention has been completed.

That is, according to the present invention, there are provided a plurality of relay terminals having a connection portion to which the electrode material is electrically connected inside a housing having an insertion hole through which the output electrode material of the solar cell is inserted. And a terminal box constituting an output unit of a solar cell module provided with one or more bypass diodes connected between these relay terminals, wherein a thin bare chip is used as the bypass diode, and each is fixed to the relay terminal. And a bypass circuit comprising a thin bare chip sandwiched between overlapping portions of a pair of conductive metal sheets extending between the relay terminals so as to face each other. (A) Change in ambient temperature of bare chip based on the influence of sunlight, roof temperature, etc. (B) Bear based on heat generated by current (C) The temperature of the bare chip surface, which is a combination of the temperature change factors of the heat radiation temperature drop of the bare chip based on the heat conduction through each conductive metal sheet bonded to the upper and lower electrode layers, is the thermal breakdown temperature. As described below, a terminal box is provided in which a cross-sectional area of each conductive metal sheet and a bonding area with respect to the electrode layer are set.

[0010] Since such a terminal box has a configuration in which a bypass diode of a thin bare chip is sandwiched between overlapping portions of a conductive metal sheet extending between relay terminals, heat generated in the bare chip is not transferred to the upper and lower electrode layers. The heat is quickly dissipated by heat conduction through the conductive metal sheet or the like bonded to the metal sheet, and the cross-sectional area and the bonding area of the conductive metal sheet are reduced based on the temperature change factors (A) to (C). Because it is set, despite the rapid temperature change of the terminal box installation environment, excellent heat dissipation through the conductive metal sheet is maintained, and the bypass function of the bare chip that supplies the necessary current to the bypass circuit is provided. It is surely maintained.

Here, in the terminal box in which the temperature change of the bare chip surface when the bypass circuit combining the temperature change element (B) and the temperature change element (C) is energized is a temperature rise of 17 ° C. or less per 1 A of current, A sufficient bypass function is maintained even in a high temperature environment such as summer.

After the bypass diode is provided,
In a terminal box into which a potting material is injected into the inside of a housing, and in a terminal box in which heat conduction by the potting material is taken into consideration as a temperature change element (C), a heat radiation effect through the potting material is added. In addition, the heat radiation temperature drop of the bare chip of the temperature changing element (C) becomes large, and it is more effective when a silicon resin excellent in heat conductivity is used as a potting material.

Further, if a copper plate having a high thermal conductivity is used as the conductive metal thin plate, the heat radiation temperature drop of the bare chip through the conductive metal thin plate which is a temperature changing element (C) becomes large.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1: has shown the whole structure of the solar cell module output part 10 in this invention, FIGS. 1-14 show the typical embodiment of the terminal box which concerns on this invention, and the code | symbol 1 in a figure is a terminal box, 2 is a terminal box. Bare chips,
Reference numerals 3a and 3b denote conductive metal sheets, respectively.

As shown in FIGS. 1 and 2, a terminal box 1 according to the present invention comprises two lead wires connected to an output material of a solar cell, for example, a positive electrode and a negative electrode of a solar cell, respectively. A plurality of relay terminals 4, 4 having a connection portion 41 in which the electrode material is electrically connected by a joining means such as soldering inside a housing 5 having an insertion port 5a through which A terminal box 1 constituting an output unit 10 of a solar cell module provided with a bypass diode connected between the relay terminals 4 and 4. The thin box 2 is used as the bypass diode. A pair of conductive metal thin plates 3a, 3a extending between the relay terminals 4, 4 facing each other.
By providing the bypass circuit structure 7 sandwiching the bare chip 2 in the overlapping portion 31 of b, the heat generated in the bare chip 2 allows the conductive metal thin plate 3a having a wide contact area with the bare chip to be used. is rapidly radiated by heat conduction through 3b and the relay terminal 4 or the like, each of the conductive metal sheet 3a shown in simplified view of FIG. 3, the junction area S ₂ to the cross-sectional area S ₁ and the electrode layer 3b below By setting as shown, excellent heat dissipation through the conductive thin metal plates 3a and 3b is maintained despite the rapid temperature change of the terminal box installation environment, and the necessary current is supplied to the bypass circuit. This is a terminal box in which the bypass function of the bare chip 2 is reliably maintained.

That is, in the present invention, the cross-sectional area S ₁ and the joint area S ₂ of the conductive metal thin plate 3a (3b) are determined when a predetermined required amount of current flows through the bypass circuit formed by the bypass circuit structure 7. And at least the following (A)
(C): (A) Change in ambient temperature of bare chip due to the influence of sunlight, roof temperature, etc. (B) Self-temperature rise of bare chip due to heat generated by energization (C) Each conductive metal sheet bonded to upper and lower electrode layers The surface temperature of the bare chip 2 obtained by integrating the temperature change factors of the temperature drop of the heat radiation of the bare chip based on the heat conduction through the substrate is set to be equal to or lower than the thermal breakdown temperature of the bare chip 2.

The bare chip ambient temperature of the temperature change element (A) is the bare chip surface temperature when the solar cell module is operating and the bypass circuit is in a non-energized state. And the material properties and structure of each part of the terminal box including the housing, the operating temperature of the solar cell module, and the like.

The self-temperature rise of the temperature changing element (B) is based on the heat generation characteristics of each bare chip appropriately selected according to the capacity of the solar cell module and the like.

The heat radiation temperature drop of the temperature change element (C) is based on heat conduction through the conductive metal sheets 3a, 3b joined to the upper and lower electrode layers of the bare chip 2, and the conductive metal sheets 3a, 3b 3b is specified by the thermal conductivity, specific heat, cross-sectional area S ₁ , joining area S ₂ , length L, and the like.

The surface temperature change of the bare chip 2 when the bypass circuit energizes the temperature changing element (B) and the temperature changing element (C) is determined by the calorific value of the bare chip 2,
Thermal conductivity of the conductive metal sheets 3a, 3b and other members,
It is possible to predict by an analytical method based on the well-known differential equation of heat conduction using specific heat, a numerical method such as a difference method and a finite element method, and other methods. By setting the cross-sectional area S ₁ and the joint area S ₂ so that the temperature rises to 17 ° C. or less per _{1 A} , a terminal box that maintains a sufficient bypass function even in a high-temperature environment such as summertime is configured. is there.

Hereinafter, the configuration of each section will be described in more detail.

The relay terminal 4 is formed of a long metal plate member having a substantially rectangular shape in a plan view, and has an insertion port 5 at the bottom of the housing.
After connecting the output cable 6 by providing a connecting portion 41 on the top surface 43 to which a surplus solder is attached on the upper surface and facing the other end 44 and crimping a core wire to the other base end 44, as shown in FIG. As described above, the mounting protrusion 93 and the positioning protrusion 94 projecting upward from the housing bottom wall 52 are aligned with the corresponding mounting holes 4.
5 and 46, and by attaching the crimp ring 14 to the mounting projection 93, the relay terminal 4 is attached to the bottom wall 5
The output cables 6 and 6 are fixed to the fixing base 56 projecting from the bottom of the housing along the extending direction of the output cable, and the fixing members 5 fitted to the fixing base 56 from above.
7 and the fixing base 56, the fixing member 5
By fixing the outer sheath of the output cable 6 and the outer sheath of the output cable 6 and the housing 5 integrally with each other by ultrasonic welding, the relay cable 4 is disposed inside the housing 5 together with the relay terminal 4.

The connecting means between the relay terminal 4 and the output cable 6 is preferably further spot-welded after the crimping, and the output cable is screwed to the relay terminal. The means for arranging the inside of the housing 5 includes a mounting projection 93 instead of the crimp ring 14.
It is preferable that the tip is melted by ultrasonic waves or the like to increase the diameter, or it is screwed. The means for fixing the output cable 6 to the housing 5 includes a fixing base 56 holding the cable and a fixing base 56. It is also preferable to screw the member 57 or fix it directly to the housing by a clamp.

At the ends of the output cables 6, 6, waterproof connectors 61, 62 having plugs or sockets are provided, and these output cables 6, 6 are connected to the output of the adjacent solar cell module via the waterproof connectors. Connected to cable or incoming cable.

The bypass diode of the thin bare chip 2 is formed, for example, by forming a P-type layer on the surface of an N-type silicon wafer by a diffusion process, etching a lattice-like groove on the surface, and appearing in the groove. A glass mesa diode chip obtained by subjecting a PN junction to glass passivation, forming a diode element defined by the groove and an electrode layer on the back surface of the wafer, and separating the diode element into a plurality along the groove. Is used. The junction temperature at the PN junction of the thin bare chip is about 150 ° C., and this junction temperature is the thermal breakdown temperature of the bare chip 2. Therefore,
When manufacturing the bypass circuit structure 7, the cross-sectional area of each conductive metal thin plate 3a, 3b and the bonding area to the upper and lower electrode layers of the bare chip are determined by the above-mentioned temperature change factors (A) to
(C) is set so that the surface temperature of the bare chip is 150 ° C. or less.
As shown in FIG. 1, one end of each of the conductive metal thin plates 3a and 3b of about 0.2 mm in thickness made of oxygen-free copper is joined over substantially the entire upper and lower electrode layers of the thin bare chip 2 covered with a glass passivation layer. Thus, the bypass circuit structure 7 composed of a pair of conductive metal thin plates 3a and 3b and the thin bare chip 2 is quickly and reliably formed outside the housing. In addition, besides copper, aluminum, gold, or a simple substance or alloy of gold and silver other than copper can be suitably used for the conductive metal thin plates 3a and 3b.

The shape of each electrode layer is as follows.
45 × 2.45 mm, 2.7 × 2.7 on the cathode electrode side
mm, the width of the overlapped portion of each conductive metal thin plate joined to these electrode layers is 2.3 mm for the thin plate 3a on the anode electrode side and 4.0 mm for the thin plate 3b on the cathode electrode side.
mm, the entire surface of each electrode layer is held via a brazing metal 8 such as cream solder or the like. The bonding area S ₂ on the anode electrode side is about 5.6 mm ² , and the bonding area on the cathode electrode side is about 17 mm. .3 mm ² .

As described above, the bypass circuit structure 7 composed of the conductive metal thin plates 3a and 3b and the bypass diode of the thin bare chip 2 sandwiched between the overlapping portions 31 is:
In addition to the excellent heat dissipation described above, because it is not sealed with resin,
It is thinner than a conventional bypass diode, and has the effect of making the housing more compact. However, the present invention is not limited to such a structure, and by packaging the periphery of the overlapped portion 31 with resin sealing, workability and heat dissipation at the time of assembling the bypass circuit structure can be reduced. Further, it is also preferable to prevent a soldering iron, a tool or other objects from directly hitting the bypass diode of the thin bare chip 2 to cause thermal damage or breakage, as in the case of a protective rib described later.

When arranging the relay terminals 4, the mounting holes 46 into which the positioning protrusions 94 are inserted are formed near the base end 44 with respect to the longitudinal center of one of the relay terminals 4. When assembling the bypass circuit component 7 into the housing 5 in which the relay terminals 4 and 4 and the output cable 6 are already arranged, as shown in FIG. Then, the positioning protrusion 94 projecting upward from the relay terminal 4 is engaged with the positioning hole 34 formed in the one conductive thin metal plate 3b, so that the positioning protrusion 94 is positioned between the upper surfaces of the relay terminals 4 and 4. It is easily and quickly bridged, and the conductive metal thin plates 3a, 3b are fixed to the upper surface of the relay terminal 4 by soldering, so that the bridge direction of the bypass circuit structure 7 is not mistaken and the relay terminals 4, 4 Near each base end.

On the side edges of the conductive metal sheets 3a and 3b in the bypass circuit structure 7, a plurality of pairs of ribs 9 rising from the bottom wall 52 of the housing 5 above the conductive metal sheet 3 are provided. Are provided along the side edges. Specifically, as shown in FIG. 2, each of the conductive metal thin plates 3a, 3b
The two pairs of regulating ribs 91a and 91b provided along both side edges of the end sides 71a and 71b, and the pair of protection ribs 92 provided along both side edges of the overlapping portion 31 where the bare chip 2 is sandwiched, respectively. It is attached.

Here, the regulating ribs 91a and 91b are used to bridge the bypass circuit structure 7 between the upper surfaces of the relay terminals 4 and 4 so that the ends 71a and 7b of the conductive metal sheet 3 are located between the ribs.
1b respectively function as positioning means for the conductive metal sheet 3, and the bypass circuit construct 7
More specifically, a narrow portion 35 extending outside the relay terminal 4 is formed in advance on the end side 71a of the one conductive metal sheet that does not form the overlapped portion. In addition, by inserting the narrow portion 35 between the corresponding restricting ribs 91a, it is possible to assemble the bridge portion without erroneous bridging directions.

The protective ribs 92 also serve to bridge the bypass circuit structure 7 between the upper surfaces of the relay terminals 4, 4.
By sandwiching the overlapping portion 31 between the ribs, a soldering iron or the like used for joining the bridge circuit component 7 and the relay terminal 4 that have been bridged or for joining the output extraction electrode material and the relay terminal 4 described below. The heating means of the present invention directly contacts the overlapping portion 31 and the tool and other objects directly impact the overlapping portion 31 when the box body 11 in which the bypass circuit structure 7 is incorporated in the housing is transferred. This is intended to prevent the bypass diode from being damaged by thermal damage and impact.

In the housing, regulating ribs 91a and 91b are provided.
In addition to the protection rib 92 and other ribs, other ribs may be provided,
These ribs extend in the extending direction of the conductive metal thin plates 3a, 3b, that is, the regulating ribs 91a, so that the potting material is smoothly filled without gaps between the bypass circuit constituting body and other members and the housing bottom wall. , 91b or protective rib 9
Preferably, it is provided in parallel to 2.

The number of bypass diodes provided inside the housing 5 is appropriately determined according to the capacity of the solar cell module and the like. For example, when two bypass diodes are connected in parallel between the relay terminals 4, 4, FIG. As shown,
What is necessary is just to bridge and join two bypass circuit components 7 adjacent to each other between the upper surfaces of the relay terminals 4 and 4 in parallel. When a plurality of bypass circuit components 7 are connected in parallel in this way, the amount of current when energized is dispersed, and it is possible to suppress a rise in self-temperature due to heat generation of each bare chip of the temperature change element (B) described above.

Each of the conductive thin metal plates 3a and 3b constituting the bypass circuit structure 7 is a flat plate and has a substantially straight shape in the longitudinal direction. The conductive metal sheet repeatedly expands and contracts due to thermal expansion caused by the change, and a large shearing force may be generated in the bypass diode of the thin bare chip 2 sandwiched between the overlapping portions 31. In the case where the separation distance of the conductive metal thin plates 3 is large and the extending dimension of each conductive metal thin plate 3 is large, as shown in FIGS. It is also preferable to provide a curved part 32 or a bent part 33 on the whole or a part along the direction.

The terminal box 1 according to the present embodiment has the lid 51 fitted in the upper end opening 53 of the housing 5, and as described above, the bypass circuit is formed between the upper surfaces of the relay terminals 4, 4. Box body 11 formed by bridging and joining bodies 7
Is fixed to the back surface of the solar cell with screws, an adhesive, an adhesive, or the like in a state where the electrode member for output extraction is inserted into the inside of the housing through the insertion port 5a. After connection to the electrode material 41, as shown in FIG.
2, a predetermined space 55 in a housing in which the bypass circuit structure 7 and the relay terminals 4 and 4 are housed and surrounded by the partition wall 54
Then, a potting material 13 made of epoxy resin, polyurethane, silicon resin, or the like is injected and filled to hermetically seal each member and a connection portion thereof, and then,
As a result, the upper end opening 53 is closed, and the assembly of the terminal box 1 is completed.

The potting material 13 hermetically seals each of the members and connection portions disposed inside the housing 5,
Prevents ingress of moisture, rainwater, dust, etc., and maintains insulation while preventing corrosion, deterioration, and damage due to impact.
If a material having particularly excellent thermal conductivity is adopted as the potting material, the heat dissipation of the bare chip 2 can be further improved through the potting material filled above and below the overlapping portion 31.

In such a terminal box 1, as shown in FIG. 10, heat generated by the bare chip 2 is transferred to the conductive metal thin plates 3 a, 3 b which are in thermal contact with the upper and lower electrode layers of the bare chip 2. By assuming the relay terminal 4 and the potting material 13 that are in thermal contact with the thin plate 3a (3b) and the heat flow path using the output cable and the housing 5 that are in thermal contact with the relay terminal 4 and the potting material 13, the above-described temperature is obtained. It is possible to predict the bare chip surface temperature when the bypass circuit is energized by integrating the variable element (B) and the temperature variable element (C).

The potting material 13 is not always necessary. In this case, as shown in FIG. 11, the heat generated by the bare chip 2 is applied to the conductive metal sheet which is in thermal contact with the upper and lower electrode layers of the bare chip 2. 3a, 3b, each thin plate 3a
The relay terminals 4 and the respective relay terminals 4 which are in thermal contact with (3b)
Similarly, the bare chip surface temperature can be predicted by assuming a heat flow path using the output cable or the housing 5 as a heat transfer member that is in thermal contact with the chip.

A bypass circuit structure 7 composed of a pair of conductive thin metal plates 3 and 3 extending between the relay terminals and a bypass diode of the thin bare chip 2 sandwiched between the overlapping portions 31 is provided in a housing. Although provided above the body bottom wall 52, the present invention is not limited to such a structure in which a space is provided below, and as shown in FIG. It is also preferable that the lower surface of the mounted overlapping portion 31 is brought into close contact with the housing bottom wall 52 so as to improve heat radiation through the bottom wall 52. In this case, a heat flow path from the conductive metal thin plate 3a to the housing bottom wall 52 is added, and the heat dissipation effect of the bare chip is improved.

FIG. 1 shows another example of the terminal box.
As shown in FIG. 3 and FIG. 14, the connecting portion 41 for connecting the output extraction electrode material 12 to the relay terminal 4,
The entirety of the relay terminal 4 excluding the fixing portion for fixing the relay terminal and the vicinity thereof, and the output cable 6 connected to the base end side of the relay terminal 4 and extending outside the housing 5 are integrated with the housing 5. The terminal box 1 ′ which is formed in a suitable manner is also preferable, and the housing bottom wall 53
Is provided with a partition wall 54 'surrounding the connecting portion 41 to be hermetically sealed by filling with a potting material and a fixing portion.

The box main body 11 of such a terminal box 1 ′ inserts the relay terminal 4 and the output cable 6 already connected to the base end thereof into a mold when forming the housing 5. A mounting projection 9 formed integrally with the housing 5 by injection molding to fix the relay terminal 4 and the output cable 6 necessary for the terminal box 1 to the housing.
3, the mounting hole 45, the pressure ring 14, the fixing member 57, etc. are not required, the number of parts is small, the assembling process is simplified, and the manufacturing cost is greatly reduced. Also, partition 5
The space surrounded by 4 ′ is smaller than the space 55 surrounded by the partition wall 54 of the terminal box 1 described above, and the relay terminal base end side 44.
In this case, the size is reduced by the amount not including the connection portion with the output cable 6, and the amount of potting material to be filled is also reduced.

[0042]

Next, a comparison will be made between a terminal box according to the present invention and a conventional terminal box.

In the first embodiment, as shown in the representative embodiment, the copper plates 3a and 3b each having a thickness of 0.2 mm are formed on substantially the entire upper and lower electrode layers of the mesa type bare chip PTD27K (manufactured by Powered Limited).
And a terminal box 1 having a bypass circuit component 7 and a potting material therein, and a terminal box 1 having a bypass circuit component 7 therein and not having a potting material enclosed therein. Comparative Example 1 and Comparative Example 2 are conventional terminal boxes 101 shown in FIG. 19 using bypass diodes FSF10A60 and FSKF20A for 10A and 20A, respectively (both manufactured by Nippon Inter Corporation).

FIG. 15 shows the amount of current supplied to the bare chip in each terminal box of the first and second embodiments.
It is a graph which shows the relationship with the temperature rise measured on the surface of a bare chip at that time, and is based on the measured value of the bare chip surface temperature change which integrated the above-mentioned temperature change factors (B) and (C). FIG. 16 is a graph showing the relationship between the ambient temperature and the amount of current that can flow at the ambient temperature in each of the terminal boxes of Example 1, Example 2, Comparative Example 1, and Comparative Example 2.

As can be seen from the graph of FIG. 15, the terminal box 1 of the first embodiment according to the present invention has a temperature rise of about 11 ° C. per 1 A of current, and the terminal box 1 of the second embodiment has a temperature rise of about 14 ° C. per 1 A of current. Temperature rise of 17
℃ or less. Further, it can be seen that in Example 1 in which the silicone resin was sealed inside the terminal box, the temperature rise was suppressed as compared with Example 2 in which the silicone resin was not sealed, and heat dissipation of the bare chip was promoted by sealing the silicon resin.

According to the graph of FIG. 16, in summer or the like when the ambient temperature is 80 to 90 ° C. or more, the amount of current flowing through the bypass diode of Comparative Example 1 is about 1.07 A.
Hereinafter, the amount of current flowing through the bypass diode of Comparative Example 2 was about 1.37 A or less, and a sufficient bypass function was not maintained. On the other hand, in the bare chip of Example 1, the amount of current was 4 A at an ambient temperature of about 107 ° C. It can be seen that the bare chip of Example 2 secures a current amount of 4 A at an ambient temperature of 94 ° C. and exhibits a sufficient bypass function even in a high-temperature environment where the ambient temperature is 90 ° C. or higher.

[0047]

According to the terminal box of the first aspect,
Since the bypass diode of the thin bare chip is sandwiched between the overlapping portions of the conductive metal sheet extending between the relay terminals, the heat generated in the bare chip causes the conductive metal sheet or the like bonded to the upper and lower electrode layers. The cross-sectional area and junction area of the conductive metal sheet are set such that the heat is quickly dissipated by the heat conduction through and the bypass circuit always functions when a predetermined required amount of current flows through the bypass circuit. Therefore, the bypass function of the bare chip is reliably maintained irrespective of a sudden temperature change in the terminal box installation environment.

According to the terminal box of the second aspect, the surface temperature change of the thin bare chip when the bypass circuit is energized is:
Since the temperature rise is 17 ° C. or less per 1 A of current, a sufficient bypass function is maintained even in a high temperature environment such as summertime.

According to the terminal box of the third aspect, since the heat radiation effect through the potting material is added and the heat radiation temperature drop of the bare chip increases, for example, the cross-sectional area of the conductive metal sheet is made smaller to make the terminal box smaller. It is also possible to reduce the overall size.

According to the terminal box of the present invention, since the silicon resin having excellent thermal conductivity is used as the potting material, the heat radiation temperature drop of the bare chip is further increased.

According to the terminal box of the present invention, since a copper plate having a high thermal conductivity is used as the conductive metal sheet, the temperature drop of the heat radiation of the bare chip through the conductive metal sheet becomes large. It is possible to reduce the size of the entire terminal box.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an entire configuration of an output unit including a terminal box and an output cable according to a typical embodiment of the present invention.

FIG. 2 is an explanatory view showing a terminal box and an output cable in an uncovered state.

FIG. 3 is an exploded explanatory view showing a main part of connection between each conductive metal thin plate and a bare chip in the bypass circuit structure.

FIG. 4 is an explanatory diagram showing a state in which a relay terminal and an output cable are assembled in a housing.

FIG. 5 is an explanatory diagram showing a bypass circuit structure inside the terminal box.

FIG. 6 is an explanatory diagram showing a state in which a bypass circuit structure is assembled between upper surfaces of relay terminals.

FIG. 7 is an explanatory view showing an example in which two bypass circuit components are bridged in parallel between the upper surfaces of the relay terminals.

FIGS. 8A and 8B are explanatory diagrams showing modified examples of the bypass circuit structure.

FIG. 9 is an explanatory sectional view showing a state where the terminal box is attached to the solar cell.

FIG. 10 is an explanatory view showing each heat transfer member that dissipates heat generated in a bare chip.

FIG. 11 is an explanatory view showing heat transfer members that dissipate heat generated in a bare chip in an example of a terminal box that is not filled with a potting material.

FIG. 12 is an explanatory view showing heat transfer members that dissipate heat generated in a bare chip in an example of a terminal box in which a lower surface of a thin plate overlapping portion is closely attached to a housing bottom wall.

FIG. 13 is a perspective view showing a modification of the terminal box.

FIG. 14 is an explanatory view showing a terminal box and an output cable in an uncovered state.

FIG. 15 is a graph showing the relationship between the amount of current supplied to the bare chip and the temperature rise measured on the surface of the bare chip at that time.

FIG. 16 is a graph showing the relationship between the ambient temperature and the amount of current that can flow at the ambient temperature.

FIG. 17 is an explanatory diagram showing solar cell modules arranged and installed on a roof.

FIG. 18 is an explanatory diagram showing an output unit of the solar cell module.

FIG. 19 is an explanatory view showing the internal structure of a conventional terminal box.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1, 1 'Terminal box 10 Output part 11 Box body 12 Electrode material 13 Potting material 14 Crimp ring 2 Bare chip 3a, 3b Thin plate 31 Overlapping part 32 Curved part 33 Curved part 34 Positioning hole 35 Narrow part 4 Relay terminal 41 Connection Part 42 upper surface 43 distal end 44 proximal end 45 mounting hole 46 mounting hole 5 housing 5a insertion opening 51 lid 52 bottom wall 53 upper opening 54, 54 'partition wall 55 space 56 fixing base 57 fixing member 6 output cable 61 waterproof connector 62 waterproof connector 7 bypass circuit assembly 71a, 71b end 8 braze alloy 9 ribs 91a, 91b regulating ribs 92 protect rib 93 mounting projection 94 positioning projection S ₁ the cross-sectional area S ₂ junction area 100 solar cell module 101 terminal box 102 Bypass diode 104 Relay Child 105 housing 105a through opening 120 solar cell 121 leads 130 support table 130a insertion groove 140 drop cables 145 sites 152 bottom wall

Claims (5)

[Claims] 1. A plurality of relay terminals each having a connection portion to which the electrode material is electrically connected inside a housing having an insertion hole through which an output electrode material of the solar cell is inserted, and A terminal box constituting an output unit of a solar cell module provided with one or more bypass diodes connected between relay terminals, wherein a thin bare chip is used as the bypass diode, each of which is fixed to a relay terminal and faces each other. And a bypass circuit comprising a pair of conductive thin metal plates extending between the relay terminals and sandwiching the bare chip between the overlapping portions, and a predetermined required current flows through the bypass circuit. At least, the following (A) ~
(C): (A) Change in ambient temperature of bare chip due to the influence of sunlight, roof temperature, etc. (B) Self-temperature rise of bare chip due to heat generated by energization (C) Each conductive metal sheet bonded to upper and lower electrode layers The cross-sectional area of each conductive metal sheet and the bonding area to the electrode layer are set such that the surface temperature of the bare chip obtained by integrating the respective temperature change elements of the heat radiation temperature drop of the bare chip based on the heat conduction through is not more than the thermal breakdown temperature. A terminal box that can be set individually. 2. The method according to claim 1, wherein the change in the surface temperature of the bare chip when the bypass circuit energizes the temperature change element (B) and the temperature change element (C) is a temperature rise of 17 ° C. or less per 1 A of current. Terminal box. 3. A terminal box into which a potting material is injected after disposing a bypass diode, wherein heat conduction by the potting material is taken into consideration in a temperature changing element (C). Or the terminal box according to 2. 4. The terminal box according to claim 3, wherein a silicone resin is used as said potting material. 5. The terminal box according to claim 1, wherein the conductive metal sheet is a copper sheet.