DE112014005098T5 - Apparatus for measuring the power of a solar cell and method for measuring the power of a solar cell - Google Patents

Abstract

A device for measuring the power of a solar cell, comprising a current measuring terminal, which consists of a plurality of arranged probe pins and is configured to measure the current characteristics of a solar cell; a terminal for voltage measurement, which consists of a plurality of arranged probe pins and is configured to measure the voltage characteristics of a solar cell; and a bracket configured to hold the current measuring terminal and the voltage measuring terminal in parallel, the probe pins of the current measuring terminal and the probe pins of the voltage measuring terminal each having a contact portion designed to to contact the finger electrodes of the solar cell, and wherein a surface of the contact part has a plurality of grooves.

Description

Technical part

The present invention relates to a device for measuring the power of a solar cell and a method for measuring the power of a solar cell.

State of the art

As measurement devices for measuring the electrical characteristics of solar cells, there have conventionally been used devices for measuring the performance of solar cells equipped with probe pins which come in contact with solar cell busbar electrodes (see, for example, PTL 1) and PTL 2).

In order to save production costs by reducing the amount of the electrode material such as Ag paste, as well as reduce the number of production processes of a solar cell, a method has recently been proposed in which a flat cable which directly constitutes a connection member is orthogonal over a conductive adhesive film is connected to finer electrodes without providing a busbar electrode. The solar cell with this busbar-less (without "busbar") structure has the same or a better current collection capacity than solar cells on which bus bar electrodes are formed.

When electrical characteristics of the aforementioned solar cell of the busbar-less structure are measured, it is necessary to bring the probe pins into direct contact with the finger electrodes.

However, when a conventional apparatus for measuring the power of a solar cell is used, it is often the case that the distances of the provided probe pins and the distances between the formed finger electrodes do not match. As a result, conduction can not be achieved in all the finger electrodes, and some finger electrodes fail as measurement targets, whereby accurate electrical characteristics can not be measured.

In order to solve the above-mentioned problems, the present inventors proposed a solar cell measuring device (see, for example, PTL 3), which has a plurality of probe pins intended to contact linear electrodes (finger electrodes) formed on a surface of a solar cell, and a holder, which holds the probe pins comprises. The solar cell measuring apparatus includes a current measuring terminal in which the probe pins are arranged and configured to be placed on the linear electrodes to measure the current characteristics of the solar cell, and a voltage measuring terminal in which the probe pins are disposed are and are configured to be placed on the linear electrodes to measure the voltage characteristics of the solar cell. In addition, the connection for current measurement and the connection for voltage measurement are provided in parallel.

The proposed technology solves the problem that some of the finger electrodes fall out of the targets.

The finger electrodes of a solar cell are often produced by applying an Ag paste by screen printing and subsequent baking. Therefore, the finger electrodes vary in the direction of their thickness. Accordingly, the contact area between each probe pin and each finger electrode is not constant, even if the proposed technology is used. As a result, there is a fluctuation in contact resistance, making it difficult to obtain an accurate power value.

Accordingly, there is currently a need for a device for measuring solar cell performance and a method of measuring solar cell performance, each of which reduces the variation in measured resistance values and achieves stable power measurements.

Bibliography

patent literature

• PTL 1: Japanese Patent Application Disclosure (JP-A) No. 2006-118983
• PTL 2: JP-A No. 2011-99746
• PTL 3: JP-A No. 2013-102121

Summary of the invention

Technical problem

The present invention aims to solve the aforementioned various problems of the prior art and to achieve the following object. In particular, an object of the present invention is to provide a device for measuring the power of a solar cell and a method for measuring the power of a solar cell, in which fluctuations in the measured resistance values are reduced and stable power measurements are realized.

the solution of the problem

• <1> A device for measuring the power of a solar cell, comprising a current measuring terminal configured of a plurality of probe pins arranged and configured to measure the current characteristics of a solar cell; a terminal for voltage measurement, which consists of a plurality of probe pins, which are arranged, and configured to measure the voltage characteristics of a solar cell; and a bracket configured to hold the power measurement terminal and the voltage measurement terminal in parallel, wherein the probe pins of the current measuring terminal and the probe pins of the voltage measuring terminal each have a contact portion intended to contact the finger electrodes of the solar cell, the surface of the contact portion having a plurality of grooves.
• <2> A device for measuring the power of a solar cell according to <1>, wherein the shapes of the grooves are a plurality of concentric circles of different diameters.
• <3> A device for measuring the power of a solar cell according to <2>, wherein the concentric circles having different diameters have an average distance of 30 μm to 300 μm between the adjacent grooves.
• <4> A device for measuring the performance of a solar cell according to any of the items <1> to <3>, wherein the grooves have an average depth of 30 μm to 250 μm.
• <5> The apparatus for measuring the power of a solar cell according to any of the items <1> to <4>, wherein the probe pins of the current measuring terminal are arranged in zigzag lines, and the probe pins of the voltage measuring terminal are arranged in zigzag lines.
• <6> A method of measuring the performance of a solar cell, comprising: Arranging the current measuring terminal and the voltage measuring terminal of the solar cell power measuring apparatus according to any one of the items <1> to <5> on finger electrodes of a solar cell; and Measuring the electrical characteristics of the solar cell while emitting light on a surface of the solar cell.

Advantageous Effects of the Invention

The present invention can solve the various problems of the prior art mentioned above, solve the aforementioned object, and provide a solar cell power measuring apparatus and a solar cell power measuring method by which, respectively, variations in measured resistance values are reduced and stable power measurements are realized.

Brief description of the drawings

1A FIG. 12 is a bottom view illustrating an example of a contact part of a probe pin. FIG.

1B is a cross-sectional view of the contact part of 1A ,

2 FIG. 12 is a bottom view illustrating another example of a contact part of a probe pin. FIG.

3A FIG. 12 is a bottom view illustrating another example of a contact part of a probe pin. FIG.

3B is a cross-sectional view of the contact part of 3A ,

4 Fig. 10 is a photograph showing a lower surface of an example of a contact part of a probe pen.

5 Fig. 10 is a photographic perspective view showing an example of a finger electrode in a solar cell.

6A FIG. 12 is a schematic view illustrating a contact point between the contact part of a probe pin and a finger electrode at the time of power measurement performed by a conventional apparatus for measuring the power of a solar cell.

6B FIG. 12 is a schematic view illustrating an example of a contact point between the contact part of a probe stylus and a finger electrode at the time of power measurement performed by a solar cell power measuring apparatus according to the present invention.

7 FIG. 15 is a perspective view explaining an example of a method of performing an electric measurement of a solar cell using the solar cell performance measuring apparatus of the present invention. FIG.

8th FIG. 15 is a perspective view illustrating an example of the apparatus for measuring the performance of a solar cell according to the present invention.

9 FIG. 14 is a bottom view illustrating an example of the current measurement terminal and the voltage measurement terminal. FIG.

10 FIG. 14 is a bottom view illustrating another example of the current measurement terminal and the voltage measurement terminal. FIG.

11 FIG. 12 is a side view illustrating a state in which the current-measuring terminal in which the probe pins are arranged in zigzag lines is brought into contact with finger electrodes. FIG.

12 FIG. 12 is a bottom view illustrating another example of a contact part of a probe pin. FIG.

13 FIG. 12 is a bottom view illustrating another example of a contact part of a probe pin. FIG.

14 FIG. 10 is a side view illustrating another example of a contact part of a probe pin. FIG.

15 FIG. 14 is a view for explaining a current measurement performed by a device for measuring the power of a solar cell. FIG.

16 FIG. 14 is a view for explaining a voltage measurement performed by a device for measuring the power of a solar cell. FIG.

17A FIG. 12 is a bottom view of the contact part of the probe pin of Example 1. FIG.

17B is a cross-sectional view of the contact part of 17A ,

18 FIG. 12 is a schematic view illustrating the arrangements of the current measurement terminal and the voltage measurement terminal of Example 1. FIG.

19 Fig. 10 is a schematic view explaining the method of measuring the electrical characteristics in the examples.

Description of the embodiments

Device for measuring the power of a solar cell

The apparatus for measuring the power of a solar cell of the present invention comprises a terminal for measuring current, a terminal for measuring voltage, and a holder. The device for measuring the power of a solar cell may optionally include other components, if necessary.

<Connection for current measurement and connection for voltage measurement>

The connection for current measurement consists of a plurality of probe pins, which are arranged.

The current sense terminal is a terminal configured to measure the current characteristics of a solar cell.

The terminal for voltage measurement consists of a plurality of probe pins, which are arranged.

The voltage measurement terminal is a terminal configured to measure the voltage characteristics of the solar cell.

For example, the terminals of the probe pins of the current measuring terminal are connected to each other via a copper cable by soldering and connected to a current meter (ammeter).

For example, the terminals of the probe pins of the terminal for voltage measurement are connected to each other via a copper cable by soldering and connected to a voltage meter (voltmeter).

<< probes pen >>

Each of the probe pins of the current measuring terminal and the probe pins of the voltage measuring terminal has a contact portion which is intended to contact a finger electrode of the solar cell, a surface of the contact portion having a plurality of grooves. In particular, the probe pin has a contact part which is intended to contact a finger electrode of the solar cell, and a surface of the contact part has a plurality of grooves.

Since the surface of the contact part has a plurality of grooves, the contact area between the probe pin and the finger electrode can be increased. As a result, fluctuation of the measured resistance values is reduced, and a stable power measurement is realized.

- groove -

The shape of the groove is appropriately selected depending on the intended purpose without limitation; Examples thereof include a linear shape and a circular shape. The shape of the grooves is an external appearance of the groove. For example, its shape is a shape of the groove observed from below in a view of the contact part.

Shapes of the grooves may be, for example, a lattice shape or a plurality of concentric circles of different diameters. The shapes of the grooves are preferably concentric circles of different diameters, because such a variation in a resistance value can be reduced.

The cross-sectional shape of the groove is appropriately selected depending on the intended purpose without limitation. Examples are a rectangle and a triangle.

An example of the grooves will be explained with reference to the examples. 1A Fig. 11 is a bottom view illustrating a contact part having a plurality of grooves which are a plurality of concentric circles of different diameters; 1B is a cross-sectional view of the contact part. The average depth of the grooves in 1B is 45 μm, and the shape of each groove in cross section is an equilateral triangle, the lower part of the groove being the vertex (vertex angle: 60 °) of the triangle; and a surface of the contact part represents the base of the triangle.

Another example of the grooves will be described with reference to a drawing. 2 Fig. 10 is a bottom view illustrating a contact part having a plurality of grooves arranged in a lattice.

Another example of the grooves will be described with reference to drawings. 3A Fig. 12 is a bottom view illustrating a contact part having a plurality of grooves which are a plurality of concentric circles having different diameters; and 3B is a cross-sectional view of the contact part. The in the 3A and 3B shown grooves are identical to those in the 1A and 1B However, because the grooves are concentric circles, they differ in that the central groove is the largest and deepest. Such an embodiment is an embodiment of the present invention.

4 Fig. 10 is a photograph showing a lower surface of an example of the contact part of the probe pin.

5 Fig. 10 is a photographic perspective view showing an example of a finger electrode in a solar cell.

6A FIG. 12 is a schematic view illustrating a contact point between the contact part of a probe pin and a finger electrode at the time of power measurement performed by a conventional device for measuring the power of a solar cell.

6B FIG. 12 is a schematic view illustrating an example of a contact point between the contact part of a probe pin and a finger electrode at the time of power measurement performed by a solar cell power measuring device according to the present invention.

As in 5 As shown, the thickness of the finger electrode in the solar cell is not uniform, and the finger electrode has a corrugated shape.

Since the finger electrode is in the state described above, a conventional device for measuring the power of a solar cell has due to the flatness of the contact part 4b less contact points between a contact part 4b a probe pin and the finger electrode 3a , as in 6A shown.

On the other hand, the device for measuring the power of a solar cell of the present invention has many contact points between a contact part 4b a probe pin and a finger electrode 3a on, since the contact part 4b of the probe pin has a plurality of grooves, as in 6B shown. As a result, the contact area between the probe pins and the finger electrodes can be increased.

The average distance between adjacent grooves in the above-described grooves is appropriately selected depending on the intended purpose without limitation. The average distance is preferably in the range of 30 μm to 300 μm , more preferably in the range of 30 microns to 220 microns, and more preferably in the range of 40 microns to 150 microns. The average distance in the most preferable range is advantageous because it can reduce a fluctuation in a resistance value.

The distance between adjacent grooves is a distance between the centers of two adjacent grooves. The average distance is an average when the distance is determined at ten randomly selected points on the contact part.

The average depth of the grooves is appropriately selected depending on the intended purpose without limitation. The average depth is preferably in the range of 30 μm to 250 μm, more preferably in the range of 45 μm to 210 μm.

Among the grooves, the depth of the grooves may be the same or different.

The average depth represents an average when the depth of the groove is determined at ten randomly selected points on the contact part.

The average width of the grooves is appropriately selected depending on the intended purpose without limitation. For example, the average width of the groove is in the range of 10 μm to 100 μm.

The average width represents an average when the width of the groove is determined at ten randomly selected points on the contact part.

The arrangement of the probe pins in the current measuring terminal or in the voltage measuring terminal is suitably selected depending on the intended purpose without limitation. Examples include a linear array and a zigzag arrangement. Among them, a zigzag arrangement is preferred. That is, the probe pins of the current measuring terminal are preferably arranged in zigzag lines. The probe pins of the terminal for voltage measurement are preferably arranged in zigzag lines.

The method of forming the grooves is suitably selected depending on the intended purpose without limitation. Examples of the method include milling (cutting).

<< Solar Cell >>

The solar cell is appropriately selected depending on the intended purpose without limitation. Examples of the solar cell include a thin film solar cell and a crystalline solar cell.

The solar cell is preferably a solar cell with a busbar-less structure.

Examples of crystalline solar cells include a monocrystalline silicon solar cell and a polycrystalline silicon solar cell.

Examples of the thin film solar cell include an amorphous silicon solar cell, a CdS / CdTe solar cell, a dye solar cell, an organic thin film solar cell, and a microcrystalline silicon solar cell (a tandem solar cell).

The solar cell contains finger electrodes as a collector electrode.

The finger electrodes are typically formed by applying an Ag paste to a light-receiving surface of the solar cell by screen printing and then baking the paste. Further, the finger electrodes are formed by forming a plurality of lines each having a width of, for example, 50 μm to 200 μm with a predetermined pitch of, for example, 2 mm, almost in parallel.

The solar cell comprises a photoelectric conversion element.

A back electrode formed of, for example, aluminum or silver is deposited on a backside, i. h., One of the light-receiving surface of the photoelectric conversion element opposite side provided. For example, the back electrode is formed on a back side of the solar cell by screen printing or sputtering.

The size of the solar cell is suitably selected depending on the intended purpose without limitation. An example of the size of the solar cell is 156 mm × 156 mm.

<Mount>

The mount is appropriately selected depending on the intended purpose without limitation, provided that the mount is a mount which can hold the current measurement terminal and the voltage measurement terminal in parallel.

The material for the holder is appropriately selected depending on the intended purpose without limitation. Examples of the material of the holder include a resin material. Examples of the resin material include a glass epoxy resin, an acrylic resin and a polycarbonate resin.

The shape of the holder is appropriately selected depending on the intended purpose without limitation. Examples of the shape of the holder include a rectangle.

For example, in the rectangular support, the upper surface and the lower surface of the support each consist of a pair of long sides each having a length corresponding to the length of one side of the solar cell and a pair of short sides each having a length. which corresponds to the width of the connection for current measurement and the connection arranged parallel thereto for voltage measurement. For example, the above-described plurality of probe pins in the holder are embedded over the length between the upper surface and the lower surface of the holder in the predetermined arrangements to form the current measurement terminal and the voltage measurement terminal.

Method for measuring the power of a solar cell

The method of measuring the performance of a solar cell of the present invention comprises an arranging step and a measuring step. The method of measuring the performance of a solar cell may optionally include further steps, if necessary.

<Arranging step>

The arranging step is appropriately selected depending on the intended purpose without restriction, provided that the arranging step comprises arranging the current measuring terminal and the voltage measuring terminal of the solar cell power measuring apparatus of the present invention on the finger electrodes of the solar cell.

<Measuring step>

The measuring step is suitably selected depending on the intended purpose without limitation, provided that the measuring step comprises measuring the electrical characteristics of the solar cell when emitting light onto a surface of the solar cell.

Examples of the electrical characteristics are I-V characteristics.

Hereinafter, an example of the apparatus for measuring the power of a solar cell and the method for measuring the power of a solar cell of the present invention will be explained with reference to the drawings.

[First Device for Measuring the Power of a Solar Cell]

As in the 7 and 8th shown comprises a device 1 for measuring the power of a solar cell, a plurality of probe pins 4 , which are designed with a surface electrode 3 attached to a surface of a solar cell 2 is designed to make contact, and a holder 5 which the probe pins 4 holds. In the device 1 There is a connection for measuring the power of a solar cell 6 for current measurement from the arranged probe pins 4 , and a connection 7 for voltage measurement consists of the arranged probe pins 4 ,

In the device 1 for measuring the power of a solar cell are the terminals of the probe pins 4 of the connection 6 for current measurement connected to each other via a copper cable by soldering and with an ammeter 8th connected. In the device 1 for measuring the power of a solar cell are the terminals of the probe pins 4 of the connection 7 for voltage measurement connected to each other via a copper cable by soldering and with a voltage measuring device 9 connected.

Every probe pin 4 includes a pen body 4a which is in the holder 5 is held, and a contact part 4b which is at one end of the pen body 4a is provided and in contact with a surface electrode 3 a solar cell 2 is brought. The pen body 4a is cylindrically shaped, and the contact part 4b is cylindrical in shape, with a larger diameter than the diameter of the pen body 4a , Because the pen body 4a of the probe pin 4 in the holder 5 is held, is the contact part 4b from the bottom surface 5b the holder 5 and the tail of the pen body 4a stands out of the upper surface 5a the holder 5 out. Then the connections of the pen main parts become 4a the probe pins 4 coming from the upper surface 5a the holder 5 stand out, connected to a copper cable by soldering, creating a connection 6 for current measurement and a connection 7 be formed for voltage measurement, each by arranging the probe pins 4 along the long side of the bracket 5 is formed.

In addition, in a surface of the contact part 4b of the probe pin 4 Grooved trained.

The holder 5 which the probe pins 4 holds is formed using a resin material into a rectangular plate. The upper surface and the lower surface 5a and 5b the holder 5 each consist of a pair of long sides, each having a length which is the length of one side of the solar cell 2 corresponds, and a pair of short sides, each having a width, that of the width of the arranged in the predetermined shape probe pins 4 equivalent. The probe pins 4 are then in the holder 5 over the length between its upper surface 5a and its bottom surface 5b embedded in the predetermined arrangements to the terminal 6 for current measurement and connection 7 to form the voltage measurement.

[[Linear arrangement]]

As in the 8th and 9 shown are the connection 6 for current measurement and connection 7 for voltage measurement parallel to the lower surface 5b the holder 5 arranged. In addition, the connection 6 for current measurement and connection 7 for voltage measurement in each case in a row along the long side of the lower surface 5b the holder 5 educated. Each of the probe pins 4 which the connection 6 for current measurement and connection 7 to form the voltage measurement, has a contact part 4b on, which is a cylinder with a diameter of 3.5 mm. The distance S1 between two adjacent contact parts 4b is 0.1 mm, which is shorter than the usual distance between finger electrodes.

Since the distance S1 between the contact parts 4b in contact with the surface electrode 3 the solar cell 2 kick in the connection 6 for current measurement is 0.1 mm, the contact parts 4b with a pitch ("pitch") shorter than the usual distance (for example, 1.0 mm to 2.0 mm) between the finger electrodes 3b , for example in the solar cell 2 a so-called busbar-less structure in which a plurality of the finger electrodes 3a parallel to each other with the predetermined distance as the surface electrode 3 are formed. Even if the distances between the finger electrodes 3a the solar cell 2 can be varied, therefore, the device 1 for measuring the power of a solar cell for all finger electrodes 3a be used with the different distances. When the thicknesses of the finger electrodes 3a can also be varied, a contact area between the probe pin 4 and the finger electrode 3a be enlarged by a plurality of grooves on the surface of the contact part 4b of the probe pin 4 be provided to reduce a fluctuation of the measured resistance values. This realizes a stable power measurement.

Because the connection 6 to Current measurement and the connection 7 for voltage measurement in the device 1 For measuring the power of a solar cell as described above, the number of probe probes in contact with the finger electrodes 3a can be increased, compared to the number in a measuring device, in which an array of probe electrodes functions both as a terminal for current measurement and as a terminal for measuring voltage. In particular, by using the device 1 for measuring the power of a solar cell, a contact between the contact parts 4b the probe pins 4 with all finger electrodes 3a will be realized. Because the connection 6 for current measurement and connection 7 For voltage measurement are formed in parallel, can also loss of shadow by the holder 5 be kept low in the measurement of electrical characteristics without the width of the upper and lower surfaces 5a and 5b the holder 5 is expanded, and it can be a reduction in performance prevented. When the thicknesses of the finger electrodes 3a In addition, the contact area between the probe pin can be changed 4 and the finger electrode 3a be enlarged by a plurality of grooves on the surface of the contact part 4b of the probe pin 4 is provided to reduce a fluctuation of the measured resistance values. This realizes a stable power measurement.

As in 9 shown overlap the probe pins 4 of the connection 6 for current measurement and the probe pins 4 of the connection 7 for voltage measurement partially along the arrangement direction. In particular, the probe pins are 4 of the connection 6 for current measurement and the probe pins 4 of the connection 7 for stress measurement parallel to each other along the direction of the long side of the lower surface 5b the holder 5 arranged. Considered from the direction of the width of the lower surface 5b the holder 5 , orthogonal to the arrangement direction, are the probe pins 4 arranged in a way that the center of the contact part 4b of the probe pin 4 in an array between the probe pins 4 of the other array, whereby the distance S2 between the contact part 4b an array and the contact part 4b of the other array is small, for example 0.1 mm.

The connection 6 for current measurement and connection 7 for stress measurement are with respect to the direction of the width of the lower surface 5b the holder 5 tightly arranged by the contact parts 4b the probe pins 4 of the connection 6 for current measurement with the contact parts 4b the probe pins 4 of the connection 7 for voltage measurement, when viewed from the arrangement direction, partially overlap. Accordingly, the width of the holder 5 that are in contact with a surface of the solar cell 2 occurs, thereby reducing the performance due to shadow loss.

When the device 1 For example, to measure the power of a solar cell to measure the current-voltage characteristics of a 6-inch solar cell, the long sides of the top surface and bottom surface are used 5a and 5b the holder 5 156 mm long, equivalent to the length of one side of the solar cell 2 and there are 43 probe pins 4 which the connection 6 to measure the current, along the direction of the long side of the holder 5 arranged in rows of 0.1 mm apart, and next to and parallel to the array of probe probes 4 which the connection 6 for current measurement, there are 42 probe pins 4 which the connection 7 for voltage measurement, arranged at intervals of 0.1 mm accordingly.

[Zigzag arrangement]

Furthermore, the connection can 6 for current measurement and connection 7 for voltage measurement of a device 1 for measuring the power of a solar cell in zigzag lines along the direction of a long side of the lower surface 5b the holder 5 be trained as in 10 shown. Because the probe pins 4 Each array is arranged in zigzag lines, overlapping the probe pins 4 of the connection 6 for current measurement and the probe pins 4 of the connection 7 for stress measurement partly in a direction orthogonal to the arrangement direction. In particular, the probe pins are 4 of the connection 6 to measure current not only in zigzag lines along the direction of the long side of the lower surface 5b the holder 5 arranged, the probe pins 4 of the connection 6 for current measurement are also arranged in a way that the contact parts 4b adjacent probe pins 4 in terms of the direction of the width of the lower surface 5b the holder 5 , orthogonal to the arrangement direction, partially overlap. The connection 7 for voltage measurement is constructed in the same way. The distance S3 between the contact parts 4b adjacent probe pins 4 is small, for example 0.1 mm.

In this way, gaps are made along the arrangement direction by partially overlapping the contact parts 4b adjacent probe pins 4 of the connection 6 for current measurement and connection 7 for measuring voltage in the direction orthogonal to the arrangement direction. If such a device 1 for measuring the power of a solar cell for measuring the electrical characteristics of a solar cell 2 with a so-called busbar-less structure in which only a plurality of finger electrodes 3a parallel to each other as a surface electrode 3 are trained, as in 11 can be used, for example, the connection 6 for current measurement and connection 7 for voltage measurement, regardless of the distances of the finger electrodes 3a , with all finger electrodes 3a be brought into contact.

In addition, the width of the bracket 5 that are in contact with a surface of the solar cell 2 occurs to be limited by an overlapping width W of the contact parts 4b adjacent probe pins 4 of the connection 6 for current measurement and connection 7 for voltage measurement, whereby a reduction in power due to shadow loss can be prevented. By the overlap width in the direction orthogonal to the arrangement direction in the structure in which the probe pins 4 arranged in zigzag lines, in particular, are the neighboring probe pins 4 in the direction of the width of the upper surface and the lower surface 5a and 5b the holder 5 moved and moved close to the arrangement direction.

If the probe pins 4 in the direction of the width of the upper surface and the lower surface 5a and 5b the holder 5 however, the width of the bracket becomes 5 widened by the movement width. As a result, the area of the bracket 5 showing the surface of the solar cell 2 covered, which causes a reduction in power due to shadow loss.

Meanwhile, the connection can 6 for current measurement and connection 7 for voltage measurement for finger electrodes 3a be used at any intervals, as long as the contact parts 4b the adjacent probe pins 4 also overlap only partially in the direction orthogonal to the arrangement direction.

Accordingly, the overlapping width W of the contact parts becomes 4b adjacent probe pins 4 of the connection 6 for current measurement and connection 7 for measuring voltage to the predetermined width or less, for example, 0.1 mm or less. As a result, the contact parts 4b with the finger electrodes 3a without any gaps or gaps, and the width of the holder 5 can be restricted, thereby preventing a reduction in performance due to shadow loss.

When the device 1 For measuring the power of a solar cell for measuring the current-voltage characteristics of a 6-inch solar cell, for example, the long sides of the upper surface and the lower surface are used 5a and 6a the holder 5 156 mm long, equivalent to the length of one side of the solar cell 2 and there are 45 probe pens 4 which the connection 6 to measure current, in a zigzag line along the direction of the long side of the holder 5 with pitches of 0.1 mm and an overlap width W of 0.1 mm in the direction orthogonal to the arrangement direction, and beside and parallel to the array of probe probes 4 which the connection 6 to measure current, there are 44 probe pins 4 which the connection 7 for voltage measurement, equally spaced at 0.1 mm intervals.

The end of the contact part 4b of the probe pin 4 In addition to a circle, it may have any shape, such as the shape of a triangle or a rhombus, as in FIGS 12 and 13 shown. As in 14 shown, the end of the contact part 4b of the probe pin 4 Semicircular shape. Of course, the end can be flat.

The device 1 For measuring the power of a solar cell can be operated as follows. A cylinder device (not shown) is connected to the bracket 5 connected, and probes pins 4 be by up and down movement of the bracket 5 by the operation of the cylinder device vertically against the surface electrode 3 the solar cell 2 pressed. Alternatively, the probes pins 4 manually vertically against the surface electrode 3 the solar cell 2 pressed.

[Method for measuring the power of a solar cell]

The following is a method of measuring the electrical characteristics of the solar cell 2 using the device 1 for measuring the power of a solar cell explained.

A measurement of the electrical characteristics of the solar cell 2 through the device 1 for measuring the power of a solar cell is performed, for example, when the finger electrodes 3a and a return electrode 22 are formed on a photoelectric conversion element. In particular, the solar cell 2 on a scaffold 30 placed, wherein the light-receiving surface of the solar cell to which the finger electrodes 3a were trained, are directed upwards. For example, the scaffold will 30 formed by plating a Cu plate with Au, and the framework 30 causes the conduction to the return electrode 22 the solar cell 2 ,

Subsequently, the device 1 for measuring the power of a solar cell arranged so that the probe pins 4 of the connection 6 for current measurement and connection 7 for voltage measurement orthogonal to all finger electrodes 3a lie as in 7 shown, and it will be on the connector 6 for current measurement and connection 7 for stress measurement by a load applying element (not shown) with the predetermined load pressure applied. Because the connection 6 for current measurement and connection 7 for measuring voltage in the device for measuring the power of a solar cell 1 are formed, each of the contact parts 4b the probe pins 4 in contact with the finger electrodes 3a brought. Accordingly, the connection 6 For current measurement in contact with all finger electrodes, whereby the current characteristics can be measured more accurately.

The total load on the connection 6 for current measurement and connection 7 for stress measurement by the stress applying element is preferably in the range of 500 g to 3000 g. If the total load is less than 500 g, the contact between the contact parts 4b the probe pins 4 and the finger electrodes 3a insufficient, whereby the performance can be reduced. If the total load is more than 3000 g, the probe pins can 4 the finger electrodes 3a or the solar cell 2 to damage.

Because the device 1 For measuring the power of a solar cell is brought into contact with a surface of a cell, circuit structures, as in the 15 and 16 represented, established. When simulated sunlight is emitted to the surface of the cell, a measurement of the electrical characteristics of the solar cell 2 be carried out by a so-called four-terminal sensing ("four-terminal sensing").

Because the connection 6 for current measurement and connection 7 for voltage measurement in the device 1 For measuring the power of a solar cell are formed in parallel, a shadow loss due to the holder 5 be kept low in the measurement of electrical characteristics without the width of the upper and lower surfaces 5a and 5b the holder 5 is expanded, and a reduction in performance can be prevented.

In the case where a device 1 for measuring the power of a solar cell in which the probe pins 4 in every array of the port 6 for current measurement and connection 7 For voltage measurement in zigzag lines are used, gaps along the arrangement direction by partial overlapping of the contact parts 4b adjacent probe pins 4 in the direction orthogonal to the arrangement direction. Accordingly, the connection 6 for current measurement regardless of the distances between the finger electrodes 3a with all finger electrodes 3a in contact, whereby the current characteristics can be measured with higher accuracy.

In the device 1 for measuring the power of a solar cell in which the connection 6 for current measurement and connection 7 For voltage measurement in the zigzag lines described above are also arranged, the contact parts 4b at random with the finger electrodes 3a be contacted by the overlap width of the contact parts 4b adjacent probe pins 4 is set to a predetermined width or less, for example, 0.1 mm or less. In addition, the width of the bracket 5 reduces, whereby a reduction of the power due to shadow loss is prevented and thus a measurement of the current-voltage characteristics can be performed with higher accuracy.

Even if the thicknesses of the finger electrodes 3a can be changed, the contact area between the probe pin 4 and the finger electrode 3a be improved by having a plurality of grooves on the surface of the contact part 4b of the probe pin 4 to be provided. As a result, fluctuation of the measured resistance values is reduced, and a stable power measurement is realized.

It should be noted that the device 1 for measuring the performance of a solar cell used in the present invention for measuring the electrical characteristics of solar cells in which a bus bar electrode orthogonal to the finger electrodes 3a was formed, as well as the solar cell 2 the busbar-less structure described above can be used. In this case, the connection will be 6 for current measurement and connection 7 for voltage measurement of the device 1 however, a measurement can be made without any problems by measuring the terminal for measuring the power of a solar cell in contact with the bus bar electrode 6 for current measurement and connection 7 for voltage measurement, as described above, in contact with the finger electrodes 3a to be brought.

Examples

In the following, examples of the present invention will be explained; however, the examples should not be construed to limit the scope of the present invention in any way.

The following are examples of measurement of the light conversion efficiency of a solar cell 2 with a busbar-less structure by means of a device for measuring the power of a solar cell 1 to which the present invention has been applied will be explained.

(Solar cell with a busbar-less structure)

The solar cell 2 with a busbar-less structure used in the examples had a 6-inch monocrystalline silicon photoelectric conversion element, finger electrodes 3a each having a width of 80 μm and a height of 20 μm to 30 μm formed on the side of a light-receiving surface with a pitch of 2 mm, and an Ag electrode extending over the whole Surface was formed on a back. The finger electrodes were formed by screen printing using a silver paste.

(Example 1)

On a contact surface of each probe pin, one end of which had the shape of a circle (diameter 1.5 mm), grooves were formed by milling. The grooves were in the form of concentric circles at an angle of 60 ° each, had an average depth of 45 μm and an average distance (mean distance) of 60 μm, the average distance being the average distance between adjacent circles (see 17A and 17B ).

The probe pins on which the grooves were respectively formed were embedded in and fixed in a resin material (holder) so as to arrange the probe pins in zigzag lines in a total of two arrays in the cell region having a side length of 156 mm, as shown in FIG 18 shown. The tabs (pedestals) of the probe pins arranged in the manner described above were connected by soldering with one copper cable per array, thereby producing a device for measuring the performance of a solar cell.

One of the connected arrays was a power measurement port and the other array was a voltage measurement port. These ports were connected to the solar simulator used.

(Example 2)

A device for measuring the power of a solar cell was prepared in the same manner as in Example 1, except that the average distance (mean distance) of adjacent circles in the concentric circles surrounding the grooves of the probe pins 4 were changed to 120 microns was changed.

The average depth of the grooves was 95 μm.

(Example 3)

A device for measuring the power of a solar cell was prepared in the same manner as in Example 1, except that the average distance (mean distance) of adjacent circles in the concentric circles surrounding the grooves of the probe pins 4 were changed to 250 microns.

The average depth of the grooves was 210 μm.

Comparative Example 1

A device for measuring the performance of a solar cell was prepared in the same manner as in Example 1, except that there were no grooves in the contact parts 4b the probe pins 4 were trained.

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The obtained device for measuring the power of a solar cell 1 became in contact with the solar cell 2 with a busbar-less structure, as in 19 and a resistance value was measured between the probe pins and the finger electrodes. The resistance was measured after application of an electric current of 1 A.

The measurement was carried out by means of a solar simulator (PVS1116i, manufactured by Nisshinbo Mechatronics Inc.) under conditions (JIS C8913) in which the illuminance was 1000 W / m ² , the temperature was 25 ° C, and the spectrum used was AM1.5G was. The measurement was performed 5 times to determine an arithmetic mean and a standard deviation (σ) of the resistance values. The degree of fluctuation per measurement was investigated. The measured results were evaluated on the basis of the following evaluation criteria.

[Evaluation Criteria]

• A: equal to or lower than 1/3 of the standard deviation (σ) of the resistance value of Comparative Example 1.
• B: equal to or lower than the standard deviation (σ) of the resistance value of Comparative Example 1, but higher than 1/3 thereof.
• C: Higher than the standard deviation (σ) of the resistance value of Comparative Example 1.

Table 1 Ex. 1 Ex. 2 Ex. 3 Comp. Ex. 1 Shape of the end of the probe pin Concentric circles Concentric circles Concentric circles Flat Average distance: 60 μm Middle distance: 120 μm Average distance: 250 μm Average resistance (mΩ) 72.8 75.3 94.3 147.4 σ of resistance values (mΩ) 6.1 9.3 19.81 39.4 rating A A B N / A

It was confirmed that in the case where a plurality of grooves were formed in the contact part of the probe pin (Examples 1 to 3), the measured resistance values were low, the fluctuation of the resistance values was small, and a more stable power measurement was performed could, compared with the case where the contact part of the probe pin had no plurality of grooves (Comparative Example 1).

Specifically, when the average pitch of the adjacent grooves was 40 μm to 150 μm (Examples 1 and 2), the fluctuation of the resistance value was very small (the standard deviation (σ) was equal to or less than 1/3 of Comparative Example 1 ), and very good results were obtained.

Industrial applicability

The solar cell power measuring apparatus of the present invention reduces the fluctuation in the measured resistance values, whereby a stable power measurement can be realized because the contact areas of the probe pins and finger electrodes are increased.

Accordingly, the apparatus for measuring the power of a solar cell of the present invention can be suitably used for power measurements of a solar cell.

LIST OF REFERENCE NUMBERS

1

Device for measuring the power of a solar cell

2

solar cell

3

surface electrode

3a

finger electrode

4

Measuring probe pin

4a

Pin main part

4b

contact part

5

bracket

6

Connection for current measurement

7

Connection for voltage measurement

8th

ammeter

9

voltmeter

22

back electrode

30

framework

Claims (6)

Device for measuring the power of a solar cell, comprising a current measuring terminal consisting of a plurality of probe pins arranged and configured to measure the current characteristics of a solar cell; a voltage measuring terminal consisting of a plurality of probe pins arranged and configured to measure the voltage characteristics of a solar cell; and a bracket configured to hold the power measurement terminal and the voltage measurement terminal in parallel, wherein the probe pins of the current measuring terminal and the probe pins of the voltage measuring terminal each have a contact portion intended to contact the finger electrodes of the solar cell, and wherein a surface of the contact portion has a plurality of grooves. A device for measuring the power of a solar cell according to claim 1, wherein the shapes of the grooves are a plurality of concentric circles of different diameters. A solar cell power measuring apparatus according to claim 2, wherein the concentric circles having different diameters have an average pitch of 30 μm to 300 μm between adjacent grooves. A device for measuring the performance of a solar cell according to any one of claims 1 to 3, wherein the grooves have an average depth of 30 microns to 250 microns. A solar cell power measuring apparatus according to any of claims 1 to 4, wherein said probe pins of said current measuring terminal are arranged in zigzag lines, and said probe pins of said voltage measuring terminal are arranged in zigzag lines. A method of measuring the power of a solar cell, comprising arranging the current measuring terminal and the voltage measuring terminal of the solar cell power measuring apparatus according to any one of claims 1 to 5 on finger electrodes of a solar cell; and Measuring the electrical characteristics of the solar cell while emitting light on a surface of the solar cell.

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