JPH07326787A - Optical semiconductor device - Google Patents

Abstract

PURPOSE:To provide an optical semiconductor device having a thin output terminal area. CONSTITUTION:An optical semiconductor device is provided with first electrode layers 30a-30c, optical semiconductor active layers 60a-60c, and second electrode layers 70a-70c laminated on a substrate 10 having an insulating surface. Output terminal areas electrically connected to the first and second electrode layers, respectively, have two foils of solder plated metal 140a and 140c on a first electrode extension section 30 at and second electrode extension section 70ct respectively extended from the first and second electrode layers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an output terminal region in an optical semiconductor device such as a photovoltaic device.

[0002]

2. Description of the Related Art A conventional output terminal region of an optical semiconductor device is disclosed, for example, in Japanese Utility Model Publication No. 62-11023. In an optical semiconductor device in which a first electrode layer, a semiconductor photoactive layer, and a second electrode layer are laminated on an insulating substrate, the structure of the output terminal region is such that a lead wire is provided on the extension extending from each electrode layer. , It was soldered. Then, the solder layer formed by this soldering work improves the adhesive strength of the lead wire and the current collecting effect of the solder layer.
It was formed in a large area.

[0003]

The conventional optical semiconductor device described above has the following problems.

That is, since the solder layer area is increased and the solder layer thickness is increased in order to firmly connect the lead wires and improve the current collecting effect, the thickness of the output terminal region is increased. Furthermore, when a flexible substrate is used, the solder layer itself does not have flexibility, and therefore the output terminal region cannot have flexibility.

The present invention has been made to solve such a problem, and an object thereof is to provide an optical semiconductor device having a small thickness of an output terminal region. In addition, it is an object to provide a flexible output terminal region when using a flexible substrate.

[0006]

An optical semiconductor device of the present invention is an optical semiconductor device in which a first electrode layer, a semiconductor photoactive layer, and a second electrode layer are laminated on a substrate having an insulating surface. The output terminal region having a metal foil plated with solder is provided on the extension portion extending from the electrode layer.

Further, the extending portion extends toward the peripheral edge of the substrate, extends along the peripheral edge, and has a metal foil on the extending portion.

In addition, the substrate is flexible.

[0009]

The optical semiconductor device of the present invention has the above constitution,
Since the metal foil is fixed to the output terminal area by the thin solder plating layer without a thick solder layer due to the soldering work, the thickness of the output terminal area is small.

Further, since the extending portion extends toward the peripheral edge of the substrate and extends along the peripheral edge, and the metal foil is provided on this extending portion, the metal foil acts as a collector electrode.

In addition, since there is no thick solder layer due to the soldering work, when the substrate has flexibility, the flexibility of the entire optical semiconductor device including the output terminal region is not impaired.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A photovoltaic device which is an embodiment of the optical semiconductor device of the present invention will be described in detail below with reference to FIGS. In describing the present embodiment, first, a series connection structure of a plurality of power generation regions will be described, and then a structure of an output terminal region, which is a feature of the present invention, will be described.

Reference numeral 10 denotes a substrate made of a flexible metal sheet such as stainless steel or aluminum and an insulating resin film formed thereon such as polyimide, or a film substrate made of resin such as polyimide.

Reference numerals 20a to 20c are a plurality of power generation regions formed on the substrate 10, and 30a to 30c are first electrode layers divided and arranged for each power generation region 20a to 20c on the substrate 10. These first electrode layers 30a to 30c have a thickness of about 0.1.
.About.1.0 μm and made of a metal film such as a single layer structure of aluminum, titanium, nickel, copper or the like, or a laminated structure of aluminum / titanium from the substrate 10 side, a laminated structure of tungsten / aluminum / titanium from the substrate 10 side, etc. , Substrate 1
After forming a metal film over the entire surface of the substrate 0, a laser beam is irradiated to form a dividing groove 41 (width of about 50 μm) between the power generation regions 20a to 20c and at the right end of the power generation region 20c, and further in the vicinity of the inside of the outer peripheral portion of the substrate 10. Peripheral grooves 42 (width of about 50 μm) are formed in the entire area to be divided and arranged.

Reference numeral 51 is an insulating paste arranged in the dividing groove 41 over the metal films on both sides thereof, 52 is an insulating paste arranged in the outer peripheral groove 42 over the metal films on both sides thereof, and 53 is the first electrode layer 30a. .About.30c is an insulating paste formed on each of the left ends thereof. These insulating pastes 51, 52 and 53 are made of polyimide or a phenolic binder containing powder of an inorganic material such as silicon dioxide (particle size: about 1.5 to 7.0 μm). 250 ~ after being patterned
It is fired at 300 ° C. and has a height of about 10 to 50 μm and a width of about 0.
It is formed to 4 to 0.6 mm.

Reference numerals 60a to 60c denote first electrode layers 30a to 30.
A semiconductor photoactive layer (thickness of about 0.3 to 1.0 μm) in which pn or pin is laminated with amorphous silicon, amorphous silicon carbide, amorphous silicon germanium, etc. dividedly arranged on c, and 70a to 70c are semiconductor photoactive layers. Zinc oxide (ZnO), indium tin oxide (ITO), tin oxide (S)
a second electrode layer (thickness of about 0.3 to 1.0 μm) made of a transparent conductive film such as nO ₂ ) is formed over the entire surface of the semiconductor photoactive layer to form an insulating paste 52. ,
The semiconductor photoactive layers 60a to 60c and the second electrode layers 70a to 70c are separately arranged by irradiating the laser beam on the laser beam 53 to form the dividing grooves 82 and 83.

Further, reference numerals 92 and 93 denote dividing grooves 82 and 83 in order to prevent water and the like from entering through the dividing grooves 82 and 83.
Is an insulating paste that is formed by filling in.

Further, each of the power generation regions 20a to 20c is electrically connected in series with an adjacent power generation region, and the first electrode layers 30b and 30 are at the left ends of the first electrode layers 30b and 30c.
Conductive pastes 100b and 100c made of silver paste or the like are arranged between the substrate c and the substrate 10. Semiconductor photoactive layer 6 disposed on these conductive pastes 100b and 100c
0a, 60b and the second electrode layers 70a, 70b are irradiated with a laser beam to form the conductive paste 100.
b and 100c and the second electrode layers 70a and 70b are welded and electrically connected to each other, and the power generation regions 20a to 20c are connected in series. Here, the conductive pastes 100b, 10
0c is a powder of silver, nickel, aluminum or the like (particle size of about 3 to 7) in a polyimide or phenol binder.
After being patterned by screen printing, it is baked at 250 to 300 ° C., and the height is about 10 μm.
The width is about 50 μm and the width is about 0.4 to 0.6 mm.

Reference numeral 110 denotes a plurality of branch portions 111 parallel to the arrangement direction of the power generation regions 20a to 20c and these branch portions 111.
A collector electrode consisting of a stem portion 112 that is continuous at the right end of
The trunk portion 112 is located above the conductive pastes 100b and 100c and has a strip shape. Further, the trunk portion of the collector electrode 110 located at the right end is also used as the output terminal 120c described later.

The feature of the present invention resides in the structure of the output terminal area described below. First, in the output terminal region located at the left end in the arrangement direction, 30at is the first electrode layer 3
The first electrode extension portion 100at extending from 0a is a strip-shaped conductive paste that is arranged between the first electrode extension portion 30at and the substrate 10 and extends parallel to the left side. 60at is a semiconductor film formed of the same material and the same process as the semiconductor photoactive layer formed above the conductive paste 100at,
At is a second electrode pad formed on the semiconductor film 60at and having substantially the same shape as that of the second electrode layer, which is made of a transparent conductive film and made of the same material and in the same step. Here, the conductive paste 100at and the second electrode pad 70at
Is connected to the second electrode pad 70at for electrical connection.
It is welded by irradiating a laser beam from above.

Reference numeral 120a is an output terminal formed of a conductive paste formed on the second electrode pad 70at and extending parallel to the left side, and 130a is a strip-shaped copper paste extending on the output terminal 120a parallel to the left side. This copper paste 13
No. 0a enables normal soldering work, and is composed of a mixture of copper powder having a particle size of 5 to 7 μm in a weight ratio of about 90% using a phenolic resin as a binder, and after patterning by screen printing. , Cured by heat treatment. This copper paste material can easily and firmly fix the solder material.

Reference numeral 140a is a strip-shaped metal foil made of copper, which is fixed onto the copper paste 130a and whose surface is solder-plated.

On the other hand, in the output terminal region located at the right end in the arrangement direction, 30ct is an island-shaped first electrode pad 100 located on the right side of the first electrode film 30c of the power generation region 20c.
ct is a strip-shaped conductive paste that is arranged between the first electrode pad 30ct and the substrate 10 and extends parallel to the right side. Reference numeral 60ct denotes a semiconductor film which extends from the semiconductor photoactive layer 60c and is formed above the conductive paste 100ct.
ct extends from the second electrode layer 70c, and the semiconductor film 60ct
It is the 2nd electrode extension part formed above. Here, in order to reduce the electric resistance and improve the current collecting efficiency, the conductive paste 1
00ct and the second electrode extension 70ct are welded by irradiating a laser beam from above the second electrode extension 70ct,
It is electrically connected.

Reference numeral 120c is an output terminal made of a strip-shaped conductive paste extending in parallel with the right side formed on the second electrode extension 70ct, and 130c is a strip-shaped copper extending in parallel with the right side on the output terminal 120c. It is a paste. Reference numeral 140c is a rectangular plate-shaped metal foil made of copper having a surface solder-plated and fixed onto the copper paste 130c.

Here, a method of fixing the metal foils 140a and 140c onto the copper pastes 130a and 130c will be described. This fixing method is used for the copper pastes 130a, 130
c, or after applying the flux to the metal foils 140a and 140c, the metal foils 140a and 140c are applied to the copper paste 1
Metal foil 140a, which is placed on 30a and 130c with a soldering iron,
It is fixed by heating from above 140c. Also,
Conventionally, since the metal foils 140a and 140c are not solder-plated, they are soldered onto the copper pastes 130a and 130c via a solder layer separately formed on the copper pastes 130a and 130c by a soldering operation. In the present invention, since the solder-plated metal foils 140a and 140c (thickness: about 80 μm) are used, there is no separately formed solder layer (thickness: about 100 to 1000 μm), and the solder plating (thickness: about 80 μm) is omitted. The small thickness (2 μm) has an advantage that the thickness of the output terminal region can be reduced.

Here, the solder plating described in the present invention means the following. First, solder has a low melting point (typically 45
The term “plating”, which is a general term for brazing alloys or simple metals of 0 ° C. or lower), means that another metal film is adhered and covered on the surface of the metal.

As the solder material, tin, lead, indium,
Tin-lead alloy, tin-lead-antimony alloy, tin-lead-cadmium alloy can be used. As a method for forming the solder plating, electroplating, electroless plating, plasma spraying, dry plating (vacuum deposition, ion plating, sputtering) can be used.

Reference numerals 141a and 141c are lead extension portions extending from the lower ends of the metal foils 140a and 140b for leading the output to the outside. Also, the lead extension 141
a, 141c without providing the metal foils 140a, 14c
It is also possible to separately attach a lead member (not shown) on 0b. When the lead extensions 141a and 141c are provided, the thickness of the output terminal region is smaller than that of the case where a lead member is separately fixed because the lead member has no thickness.
Further, even if the lead member is used, if a solder-plated metal foil is used as the lead member, the solder layer by the soldering work is not required as in the above-described embodiment, and the thickness of the output terminal region is not required. Becomes smaller.

In this embodiment, since the metal foils 140a and 140c having a small electric resistance are fixed to the copper pastes 130a and 130c over substantially the entire area, these metal foils 140a and 140c serve as collector electrodes. The output loss can be reduced and the output can be led to the outside.
In addition, the metal foils 140a and 140c are the copper paste 130.
Although the shape is such that it extends over substantially the entire area on a and 130c, the extending length and width may be reduced within a range where a current collecting effect can be obtained.

Here, the output terminal 120 used in this embodiment.
a and 120c are omitted and copper pastes 130a and 130 are omitted.
The metal foils 140a and 140c may be directly plated on the copper pastes 130a and 130c, and the metal foils 140a and 140c may be fixed to the copper pastes 130a and 130c. In this case, since the output terminals 120a and 120c are not provided, the thickness of the output terminal area is reduced.

Further, in the present embodiment, the second electrode layers 70a to 70c are made transparent and light is incident from this side, but the first electrode layers 30a to 30c and the substrate 10 are made transparent. Light may be incident from the side.

[0032]

The optical semiconductor device of the present invention has the above-described structure. Since the metal foil is fixed to the output terminal area by the thin solder plating layer without the thick solder layer due to the soldering work, the output terminal area is reduced. Is small in thickness.

Furthermore, since the extending portion extends toward the peripheral edge of the substrate and extends along the peripheral edge, and the metal foil is provided on this extending portion, the metal foil acts as a collector electrode, and the output is provided. It is possible to reduce the loss and lead the output to the outside.

In addition, since there is no thick solder layer due to the soldering work, when the substrate has flexibility, the flexibility of the entire optical semiconductor device including the output terminal region is not impaired.

[Brief description of drawings]

FIG. 1 is a plan view showing an optical semiconductor device which is an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

[Explanation of symbols]

 10 Substrate 30a, 30b, 30c 1st electrode layer 30at 1st electrode extension part 60a, 60b, 60c Semiconductor photoactive layer 70a, 70b, 70c 2nd electrode layer 70ct 2nd electrode extension part 140a, 140c Metal foil

Claims (3)

[Claims] 1. An optical semiconductor device in which a first electrode layer, a semiconductor photoactive layer, and a second electrode layer are laminated on a substrate having an insulating surface, and on an extending portion extending from one of the electrode layers. An optical semiconductor device comprising an output terminal region having a solder-plated metal foil. 2. The extending portion extends toward the peripheral edge of the substrate, extends along the peripheral edge, and has the metal foil on the extending portion. Optical semiconductor device. 3. The optical semiconductor device according to claim 1, wherein the substrate has flexibility.