TWI491076B - Housing and method of manufacturing a housing for an optoelectronic component - Google Patents

Description

Housing for photovoltaic module and method of manufacturing same

The present application relates to a housing for an optoelectronic component, a method of manufacturing the same, and an optoelectronic component having such a housing.

The present patent application claims the priority of the German Patent Application No. 10 2010 054 59, the entire disclosure of which is hereby incorporated by reference.

In order to manufacture various photovoltaic modules based on radiation-emitting semiconductor wafers, ceramic-based housings are often used for components having high output power, because ceramics are characterized by high aging stability and Good thermal conductivity. However, such housings are relatively expensive to manufacture and costly. The manufacture of cost-effective plastic housings is often difficult due to the insufficient aging stability of a variety of plastics, which are generally due to degradation associated with ultraviolet radiation generated in semiconductor wafers. Also, plastics generally have poor adhesion to lead frames.

It is an object of the present invention to provide a housing which has high mechanical stability, high radiation stability and high aging stability, while being easily and cost-effectively produced. Further, a method of manufacturing a casing easily and reliably is provided.

The above objects are achieved by applying for an article of independent scope of the patent. Various arrangements and other forms are described in the articles of the respective scope of the patent application.

In one embodiment, a housing for a surface mountable optoelectronic component has a mounting surface for mounting the housing, a first connecting conductor, a second connecting conductor, and a housing body. The housing body has a connection region that mechanically interconnects the first connection conductor and the second connection conductor. The housing body has a surface area that covers the connection area on the side remote from the mounting surface at least in a regional manner. The connection zone and the surface zone differ from each other in terms of material.

The housing body thus has two partial regions which are optimized for different (especially different) characteristics.

Preferably, the attachment zone and the surface zone are each a polymer-material. The polymer-material is different from the ceramic material and can be processed easily and cost-effectively.

The connection zone is preferably a polymer-material having a high temperature resistance. For example, an epoxide or a thermoplastic, which is substantially PPA, LCP (Liquid Crystal Polymer) or PEEK, and is suitable for use herein.

By high temperature resistance is meant herein particularly that the material can withstand temperatures of at least 250 ° C, preferably at least 400 ° C, without exhibiting significant deterioration or deformation. Therefore, it is possible to prevent the risk of the casing being damaged (for example, due to welding) at the time of its installation.

It is preferable to select a material for the connection region so as to have good adhesion to each of the connection conductors and mechanically stably connect the connection conductors to each other. The material of the connection region can be selected in a manner that is broadly independent of the optical properties of the material of the connection region. In particular, materials which are also absorbing to radiation in the visible region of the spectrum, for example black materials, can be formed.

It is preferred to form the surface region to have high radiation stability, in particular for radiation in the ultraviolet radiation range, which is higher than the radiation stability of the connection region.

In a preferred arrangement, the material of the surface region contains an anthrone. Anthrone is characterized by high radiation stability.

Again, the material of the surface region is preferably filled with particles that are reflective with respect to electromagnetic radiation, particularly radiation in the visible region of the spectrum. For example, titanium dioxide-particles are suitable for use herein.

The housing body preferably extends between the mounting surface and the upper side in a vertical direction (i.e., a direction extending perpendicular to the mounting surface). The upper side is preferably formed from the surface area at least in a regional manner.

Preferably, at least one region of the upper side extends beyond the extent of the first connecting conductor and/or the second connecting conductor in the vertical direction. The upper side is preferably formed entirely by the surface area in this region.

By means of the surface region, the connection region located below it when viewed from the upper side can be protected from the incident radiation, so that the connection region can also be used when it is used alone for the housing body. A material that is highly damaging and has a strong deteriorating property.

An outer surface adjacent to the housing body in a lateral direction (ie, a direction extending along the mounting surface) is preferably only in a region manner, particularly in an area adjacent to the upper side, by the surface region To form.

In a preferred arrangement, the housing body has a recess for securing the optoelectronic semiconductor wafer on the side remote from the mounting surface. A semiconductor wafer can be secured in the recess and electrically conductively coupled to the first and second connection conductors.

In a preferred arrangement, the surface region forms one side of the recess. It is thus ensured that the portion of the housing body that is most strongly subjected to the generated radiation during operation of the semiconductor wafer has a sufficiently high radiation stability.

In a preferred arrangement, the first connecting conductor and/or the second connecting conductor extend completely via the housing body in a region extending in a direction perpendicular to the mounting surface. Therefore, electrical contact can be made to the at least one connecting conductor (preferably the two connecting conductors) from the mounting surface in a simple manner.

In the photovoltaic module having the above-described housing, the optoelectronic semiconductor wafer is preferably disposed in the housing and preferably electrically connected to the first connecting conductor and the second connecting conductor. Additionally, the semiconductor wafer is preferably embedded in an encapsulant, the encapsulant preferably being at least regionally adjacent to the surface region.

The encapsulant may also be formed in multiple layers. For example, a partial layer adjacent to the side of the semiconductor wafer is formed to be reflective to the radiation generated in the semiconductor wafer. Preferably, the layer of the encapsulant overlying the semiconductor wafer on the side remote from the carrier is formed such that the generated radiation is transmitted or at least semi-transmissive. Furthermore, a radiation conversion material and/or a scattering material is embedded in the encapsulation or at least in the layer of the encapsulation.

In the manufacture of a housing for an optoelectronic component, the first connecting conductor and the second connecting conductor are to be produced in accordance with an embodiment. These connecting conductors are modified in a zoned manner by the first profile to form the connection region of the housing body. The connection region mechanically interconnects the first connecting conductor and the second connecting conductor. In order to form the surface area of the housing body, the connection area must be modified in a regional manner by means of the second profile.

The formation of the housing body is thus carried out in two successively modified steps. The first profile and the second profile are suitably different in terms of material.

In a preferred arrangement, the joining zone and/or the surface zone are made by casting, injection molding or transfer molding.

In another preferred arrangement, a cleaning step is performed between the modification by the first profile and the modification by the second profile to remove the material of the first profile. Alternatively, the purification step can also be carried out by a second profile after modification.

This purification step can be carried out, for example, by a plasma method, electrolysis or mechanical means, substantially by particle beam or not by fluid.

Alternatively, in order to remove the material of the second profile, a purification step is performed after the connection zone is modified.

In the method, it is preferred that the above-mentioned connecting conductor is present in a composite for producing a plurality of casings in particular at the same time. After modification by the first and second profiles, the housing formed by the composite can be divided. The outer surface of the housing body is preferably formed at the time of division. In other words, the housing is made in a composite and at least one outer surface of the housing is created when the composite is divided into a plurality of housings.

The above method is particularly suitable for use in the manufacture of the other housing described above. The features formed in combination with the housing are therefore also suitable for use in the method and vice versa.

Other features, arrangements, and applicability will be described in the description of the various embodiments with reference to the drawings.

Elements of the same, same type, or the same effect are labeled with the same element symbols in the drawings.

The size ratios of the various elements and elements shown in the various figures and figures are not necessarily drawn to scale. Conversely, some of the elements of the various figures have been shown in an exaggerated manner for clarity and/or ease of understanding.

1 shows a cutaway view of an embodiment of a housing formed as a surface mountable housing for securing a semiconductor wafer.

The housing 1 has a housing body 2 formed as a plastic-molded body mainly composed of a polymer. The housing body 2 is formed on the first connecting conductor 31 and the second connecting conductor 32. The first connecting conductor and the second connecting conductor form a lead frame for the housing 1.

The housing body 2 has a connection region 21 and a surface region 22 directly adjacent to the connection region. The connection region 21 is directly adjacent to the first connection conductor 31 and the second connection conductor 32 and mechanically interconnects the connection conductors. The housing bodies, in particular the connection region and the surface region, are suitably formed in an electrically insulating manner. Further, the connection area forms a mounting surface 11 for mounting the housing.

The surface region 22 is formed on the side of the connection region 21 remote from the mounting surface 11 and forms the upper side 12 of the housing body 2. Mechanical stability is preferably ensured by the joint zone, so that materials for the surface zone can be selected for other purposes, such as radiation stability or ease of processability.

Each of the connecting conductors 31, 32 has a rear cut 35 in a side view, which is formed, for example, in the form of a step. With the rear cut portion, the housing body 2 (particularly the connection portion 21) can be used to achieve better engagement of the connecting conductors. The mechanical stability of the housing can therefore be increased.

In a vertical direction, that is, in a direction extending perpendicular to the mounting surface 11, the housing body 2 extends between the mounting surface and the upper side of the housing body. A recess 25 is formed in the housing body 2 from the upper side 12. In each of the notches, the respective connection conductors 31, 32 are exposed in a region manner.

The surface region 22 of the housing body 2 forms the side 250 of the recess 25. The housing body has a frame-like region 251 that surrounds the recess in the transverse direction. In the frame region, the upper side 12 of the housing body 2 is completely formed by the surface region 22.

In the recess 25, the bottom surface 252 of the housing body 2 is preferably formed only by the connecting portion 21. The bottom surface is flush with each of the connecting conductors 31, 32.

When the optoelectronic semiconductor wafer is mounted in the housing 1, the side of the recess 250 and the upper side 12 of the housing body 2 are primarily capable of withstanding radiation from the semiconductor wafer. With the surface region 22, the connection region 21 can be protected from the radiation of the semiconductor wafer.

Conversely, the outer surface 26 of the housing body extending between the mounting surface 11 and the upper side 12 of the housing body is only subjected to less radiation intensity. In the region of the outer surface 26, the connection region 21 is thus also exposed. Such an outer surface is formed in a zoned manner by the joint zone and the surface zone, which outer surface can be formed in a simple manner during manufacture by separation of the joint zone and the surface zone. However, unlike the illustrated embodiment, the surface region 22 may also completely cover the attachment region of the housing body facing the side of the outer surface to form the outer surface 26. Each of the connecting conductors 31, 32 extends completely in a vertical direction via the housing body 2, in particular the connecting region 21, in a regional manner. The first outer contact surface 311 of the first connecting conductor 31 facing the mounting surface 11 and the second outer contact surface 321 of the second connecting conductor 32 are used for external electrical connection with the housing body by the mounting surface contact.

On the side facing the upper side 12 of the housing 1, the respective connecting conductors 31, 32 form a first connection surface 312 or a second connection surface 322 for forming an electrically conductive connection with the semiconductor wafer.

The surface region 22 is preferably predominantly anthrone. Anthrone is characterized by high stability to electromagnetic radiation, especially ultraviolet radiation. In order to increase the reflectivity of the surface region, it is preferred to fill the particles into an anthrone which has a high reflectivity with respect to radiation in the visible region of the spectrum and/or in the ultraviolet spectral region. For example, titanium dioxide-particles are suitable for use herein.

The surface region preferably has a thickness of at least 30 microns. The greater the thickness of the surface region, the larger the particles can be buried in the surface region. The thickness of the surface region is preferably between 100 micrometers (inclusive) and 300 micrometers (inclusive).

Conversely, the material of the connection zone 21 does not have to be radiation stable. In particular, epoxide-materials can be used, which are typically used for encapsulants of electronic components. This typically black epoxide-material is characterized by high mechanical stability, good adhesion to materials typically used in leadframes, and low thermal resistance and is already used in electronic components. The cost is used particularly advantageously.

Moreover, the material for the connection region 21 may also comprise a mixed material having an epoxide and an anthrone, wherein the epoxide component is preferably between 20% and 80%, in particular Jiashi is between 30% (inclusive) and 70% (inclusive).

Alternatively, the connection zone 21 may comprise another high temperature resistant material, in particular a thermoplastic material, for example, an epoxide and anthrone, PPA (Polyphtalamid), LCP (liquid crystal polymerization). (Liquid crystal polymer) or PEEK (polyaryletherketone: Polyetheretherketon) mixed materials.

A cutaway view of one embodiment of a method of manufacturing a housing is shown in Figures 2A-2D. In order to simplify the drawing, only the manufacture of the housing is shown. Preferably, however, the housing is formed in a composite, the composite being arranged, in particular in the form of a strip or a matrix, for each of the regions of a housing, wherein the respective housings are The division of the complex is obtained.

As shown in FIG. 2A, a lead frame having a first connecting conductor 31 and a second connecting conductor 32 is prepared. The lead frame can be formed, for example, from a flat sheet of copper, which can be provided with a coating (not explicitly shown), either completely or at least in a regional manner, to improve weldability. For example, the coating may comprise silver, nickel, gold or palladium or a metal alloy having at least one of the foregoing materials, for example, nickel-gold or nickel-palladium-gold. Further, each of the connecting conductors 31, 32 has a rear cut portion 35 to improve the mechanical engagement with the housing body to be formed later. The connecting conductor having such a rear cut can be made, for example, by etching and/or substantially mechanically punching, punching and/or casting.

As shown in FIG. 2B, the first connecting conductor 31 and the second connecting conductor 32 are modified by the first profile and thus mechanically stably connected to each other. In particular, the transfer molding method or the injection molding method is suitable for use in retrofitting. The profile which is hardened in time forms the connection zone 21 of the housing body 2.

In the next step, the joint zone 21 is modified in a zoned manner by the second profile to form a surface region 22 for the casing body. Preferably, the attachment zone is modified only on the side opposite the mounting surface for the mounting of the finished housing.

The original material of the profile may be in fluid form or in solid form, respectively.

Prior to retrofitting by the second profile, a purification step is performed to remove the material of the first profile, such as by a plasma-method, an electrolytic process (particularly associated with high pressure water beam purification), by having other fluids Or particle beams without other fluids, or by CO ₂ -purification. Undesirable materials of the profile can thus be removed on the individual connecting conductors 31, 32.

The above purification step can also be carried out by a second profile after modification to remove the material of the second profile.

The outer surface 26 of the housing 1 is created when the composite is divided into a plurality of housings after forming the housing body having the attachment regions 21 and the surface regions 22. This division can be carried out, for example, mechanically (generally cutting or punching). Alternatively, it can be carried out chemically, for example, by wet chemical or dry chemical etching or by coherent radiation (generally laser radiation).

In order to manufacture a photovoltaic module having such a housing, it is preferred that the photovoltaic semiconductor wafer of the photovoltaic module is divided into individual housings only after it has been disposed in the housing and electrically connected to the respective connection conductors 31, 32. The case must be encapsulated and/or provided with a main lens (generally a concentrating lens) as needed.

A cross-sectional view of a first embodiment of an optoelectronic component having a housing as described in connection with Figures 1 and 2A-2D is shown in Figure 3. This photovoltaic module 10 has a housing 1 in which a semiconductor wafer 4 is disposed. The semiconductor wafer 4 has a semiconductor body 43 which is produced in an epitaxial manner and which has a semiconductor layer sequence. The semiconductor layer sequence includes an active region 40 for generating radiation disposed between the first semiconductor layer 41 and the second semiconductor layer 42 of a different conductivity type.

The semiconductor body 43 is arranged on a carrier 45 which stabilizes the semiconductor body 43 mechanically. The growth substrate for the semiconductor layer sequence of the semiconductor body is not required for mechanical stability and can therefore be removed.

The first semiconductor layer 41 facing the carrier 45 is electrically conductively connected to the first contact surface 461 for contact with the semiconductor wafer by the first connection layer 46. The first contact surface is disposed in a region of the first connection layer 46 that is exposed by the removal of the semiconductor body 43.

The semiconductor body 43 is formed with at least one recess 44 facing the side of the carrier 45, which extends inwardly via the active region 40 into the second semiconductor layer 42 remote from the carrier. The second semiconductor layer 42 is electrically conductively connected to the second contact surface 471 via the carrier 45 via a second connection layer 47 , and the second contact surface 471 is disposed on the side of the carrier 45 remote from the semiconductor body 43 .

The semiconductor body 43 is mechanically and electrically conductively connected to a carrier (for example, a tantalum carrier or a tantalum carrier) by means of the connecting layer 50, for example a solder or an electrically conductive adhesive layer.

An isolation layer 48, such as an oxide- or nitride-layer, is formed between the first connection layer 46 and the second connection layer 47, which electrically separates the connection layers from each other. The spacer layer 48 additionally covers the sides of the recess 44 to prevent electrical shorting of the active region 40.

The radiation emitting surface of the semiconductor body 43 remote from the carrier 45 is not provided with an external electrical contact region, thereby preventing radiation generated by the active region from being blocked during operation of the semiconductor wafer. In order to increase the emission efficiency, the radiation emitting surface of the semiconductor wafer 4 remote from the carrier 45 is provided with a structure 49 (substantially a rough region).

The second contact surface 471 is electrically conductively connected to the first connecting conductor 31, for example by solder or an electrically conductive adhesive layer. The first contact surface 461 is electrically connected to the second connecting wire 32 of the housing 1 via a connecting wire (for example, a wire for bonding connection).

The semiconductor wafer 4 is buried in the encapsulation body 7. The envelope 7 is formed in a plurality of layers in this embodiment. A first layer adjacent to the side of the semiconductor body 4 is formed as a reflective layer 72. For example, the reflective layer can be formed with an anthrone layer in which particles (for example, titanium dioxide-particles) are embedded to increase the reflectance. By means of the reflective layer, radiation which may be emitted from the side of the semiconductor wafer 4 is directly reflected back into the semiconductor wafer and then emitted by the upper radiation emitting surface.

A second layer of the encapsulant is formed on the reflective layer 72, which is formed as a radiation transmissive layer 71. This radiation transmissive layer 71 covers the radiation emitting surface of the semiconductor wafer 4. A radiation converter is embedded in the radiation transmissive layer 71 to completely convert or at least partially convert the radiation generated in the semiconductor wafer 4. Each of the radiation converters may be uniformly or substantially uniformly distributed in the radiation transmissive layer 71. Alternatively, the radiation conversion material may also be formed unevenly in the radiation permeable layer, for example, due to deposition substantially at the interface to the reflective layer 72 and/or deposition at the interface to the semiconductor wafer 4. Caused.

A cross-sectional view of a second embodiment of the optoelectronic component is shown in FIG. This second embodiment substantially corresponds to the first embodiment described with reference to FIG. The difference is that the second semiconductor layer 42 disposed on the side of the active region 40 remote from the carrier is electrically contacted by the second contact surface 471 on the upper side. The first semiconductor layer 41 facing the carrier is in contact with the carrier via the first contact surface 461 to achieve a conductive contact.

A first connecting conductor 46 (e.g., a silver layer) acts as a mirror layer for the radiation generated in the active region 40.

Further, unlike the first embodiment, a radiation conversion element 8 is disposed on the semiconductor body 43. The radiation conversion element 8 is preferably formed as a pre-formed small plate that is secured to the semiconductor body 43 by an adhesive layer (e.g., an anthrone layer). For better displayability, the adhesive layer is not clearly shown.

The radiation conversion element 8 can be formed, for example, from a ceramic plate in which the particles for radiation conversion are combined into a ceramic.

Alternatively, the radiation conversion element 8 may be formed by a base material (for example, an epoxide or an anthrone) in which the radiation converter is embedded.

Further, the radiation transmissive layer 71 is formed in a different manner from the first embodiment to form an optical element 73, for example, a convex lens for radiation bundling.

Of course, the semiconductor wafer described with reference to FIG. 4 can also be used in the embodiment shown in FIG. The housing is also suitable for use in a semiconductor wafer where the growth substrate is not removed or only a portion is removed. The housing may also be formed such that a plurality of semiconductor wafers may be secured in the housing.

Further, the reflective layer 72 may be omitted in each of the above embodiments. In this case, the radiation emitted by the side of the semiconductor wafer 4 is deflected in the direction of the upper side 12 on the side 250 of the recess 25.

The invention is not limited to the description made in accordance with the various embodiments. Instead, the present invention encompasses each novel feature and each combination of features, and in particular, each of the various combinations of the various features of the invention, or the various features of the various embodiments, when the relevant features or related combinations are not The invention is also shown in the scope of each patent application or in the various embodiments.

1. . . case

10. . . Photoelectric component

11. . . Mounting surface

12. . . Upper side

2. . . Housing body

twenty one. . . Connection area

twenty two. . . Surface area

25. . . Notch

250. . . side

251. . . Area in the form of a frame

252. . . Bottom

26. . . The outer surface

31. . . First connecting conductor

311. . . First connection surface

312. . . First external contact surface

32. . . Second connecting conductor

321. . . Second connection surface

322. . . Second external contact surface

35. . . Rear cut

4. . . Semiconductor wafer

40. . . Active zone

41. . . First semiconductor layer

42. . . Second semiconductor layer

43. . . Semiconductor body

44. . . Notch

45. . . Carrier

46. . . First connection layer

461. . . First contact surface

47. . . Second connection layer

471. . . Second contact surface

48. . . Isolation layer

49. . . structure

50. . . Connection layer

7. . . Encapsulation

71. . . Radiation transmission layer

72. . . Reflective layer

73. . . Optical element

8. . . Radiation conversion element

9. . . Connecting conductor

Figure 1 shows a cutaway view of an embodiment of a housing.

2A through 2D show an embodiment of a method of manufacturing a housing in accordance with an intermediate step shown in a cross-sectional view.

Figure 3 shows a cutaway view of a first embodiment of an optoelectronic component.

Figure 4 shows a cutaway view of a second embodiment of an optoelectronic component.

1. . . case

11. . . Mounting surface

12. . . Upper side

2. . . Housing body

twenty one. . . Connection area

twenty two. . . Surface area

25. . . Notch

251. . . Area in the form of a frame

252. . . Bottom

26. . . The outer surface

31. . . First connecting conductor

32. . . Second connecting conductor

35. . . Rear cut

Claims (12)

A housing (1) for a photovoltaic module (10), wherein the housing (1) has a mounting surface (11) for mounting the housing, a first connecting conductor (31), and a second connecting conductor ( 32) and a housing body (2); the housing body (2) has a connection region (21) that mechanically interconnects the first connection conductor (31) and the second connection conductor (32); The housing body (2) has a surface area (22) covering at least the area of the connection area (21) on the side away from the mounting surface (11); the connection area (21) and the surface area (22) different from each other in terms of materials; the material of the surface region (22) contains an anthrone; the connection region (21) has a polymer material resistant to high temperature; the connection region (21) and the surface region (22) Directly adjacent to each other. The housing of claim 1, wherein the housing body has a recess (25) for securing the semiconductor wafer on a side remote from the mounting surface. The casing of claim 2, wherein the surface region forms a side (250) of the recess. The casing of any one of claims 1 to 3, wherein the material of the surface region is filled with particles that are reflective to electromagnetic radiation. The housing of any one of claims 1 to 3, wherein the first connecting conductor and the second connecting conductor are completely via the housing body in a regional manner in a direction extending perpendicular to the mounting surface. extend. Such as the casing of claim 1 of the patent scope, wherein The housing has a recess for securing a semiconductor wafer on a side remote from the mounting surface; the surface region forms a side of the recess; and the material of the surface region is filled with particles, the particles Electromagnetic radiation is reflected. An optoelectronic component (10) having a housing (1) according to any one of claims 1 to 3, wherein the optoelectronic semiconductor wafer (4) is disposed in the housing (1) and is electrically conductive The ground is connected to the first connecting conductor and the second connecting conductor, and the semiconductor wafer is embedded in the encapsulation body (7), and the encapsulation body (7) is adjacent to the surface area in a regional manner. A method of manufacturing a housing (1) for an optoelectronic component (10), comprising the steps of: a) preparing a first connecting conductor (31) and a second connecting conductor (32); b) using the first profile A regional manner is formed around the connecting conductors (31, 32) to form a connection region (21) of the housing body (2), which connects the first connecting conductor (31) and the second connecting conductor ( 32) mechanically interconnected; and c) formed in a regional manner around the joint zone (21) by a second profile to form a surface region (22) of the casing body (2). The manufacturing method of claim 8, wherein the joint region and the surface region are formed by casting, injection molding or transfer molding. The manufacturing method of claim 8, wherein a purifying step is performed between step b) and step c) to remove the material of the first profile. The manufacturing method of any one of claims 8 to 10, Therein, a purification step is carried out after step c) to remove the material of the second profile. The manufacturing method according to any one of claims 1 to 10, wherein the casing according to any one of claims 1 to 6 is produced.