• 专利附录
  • 专利说明
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    • 专利摘要:
    The present invention describes a method (100) for producing an LED module (10) with at least one LED chip (1). In the method (100), at least one LED chip (1) is initially provided on a preferably reflective carrier (2). Color conversion particles (3) electrically charged with a first polarity are then provided, preferably in a matrix material (4). The LED chip (1) is then charged with a second polarity opposite to the first polarity and the color conversion particles (3) are applied to the at least one LED chip (1). In the LED module (10), the top side facing away from the carrier (2) and the side surfaces of the at least one LED chip (1) are coated with a layer of color conversion particles (3) which, on this top side and on the side surfaces, have a has substantially the same strength. Furthermore, the LED chip (1) can have at least one bonding wire (5) which is then also coated with color conversion particles (3).
    公开号:AT16795U1
    申请号:TGM9005/2016U
    申请日:2016-04-27
    公开日:2020-09-15
    发明作者:
    申请人:Tridonic Jennersdorf Gmbh；
    IPC主号:
    专利说明:

    description
    METHOD OF MANUFACTURING LED MODULE
    The present invention relates to a method for producing an LED module and a correspondingly produced LED module. In particular, during the method according to the invention, a step for coating LED chips of the LED module with color conversion particles is supported by charging the LED chips with a polarity which is opposite to a polarity of the color conversion particles.
    From the prior art it is already known to coat LED chips of an LED module with color conversion particles, for example with a phosphor. The color conversion particles are usually introduced into an enveloping matrix made of, for example, silicone material. The color conversion particles then at least partially convert the light emitted by the LED chips when the LED module is in operation. In this way, different types of LED modules can be produced, for example an LED module which emits mixed-colored light, in particular white light.
    Fig. 1 shows such a conventional LED module 20 in which color conversion particles 23 are evenly distributed in a silicone matrix 24, i. over the entire volume of the silicone matrix 24. In particular, FIG. 1 shows an LED module 20 which was produced by means of a method of insulating and filling (“dam and fill” method). The LED module 20 has a plurality of LED chips 21 which are arranged on a circuit board 22 and which are encased by the silicone matrix 24 or encapsulated with it. In particular, only an inner area of the LED module 20, in which the LED chips 21 are located and which is delimited to the outside by a dam 27, is filled with the silicone matrix 24. The LED chips 21 are usually connected to one another in series by bonding wires 25 and are connected to at least two bonding pads 26 arranged outside of the dam 27.
    Although the phosphor particles 23 are evenly distributed in the silicone matrix 24, an inhomogeneous color distribution is observed over the emission angle of the light from the LED module 20. This color inhomogeneity can be explained by the fact that the light from each LED chip 21 travels a longer or shorter path through the silicone matrix 24 depending on the radiation angle, which is illustrated by the arrows in FIG. 1. The longer this path covered is the more phosphor particles 23 the light hits and the greater the probability of color conversion.
    It is also known from the prior art to produce an LED module 30 for very high phosphor densities. 2 shows such a conventional LED module 30. In the manufacturing process of this LED module 30, there is a process step during which color conversion particles 33 settle on the surface of LED chips 31 and on the surface of a circuit board 32. In the LED module 30, the color conversion particles 33 are therefore not evenly distributed in a silicone matrix 34, but are located within the dam 37 on the LED chips 31 and between the LED chips 31. This creates a thermal resistance between a heat source of the LED Module 30 - namely the color conversion particles that generate heat during color conversion - and a heat sink of the LED module 30 - namely the circuit board 32, which also serves to dissipate heat. As a result, the luminance of the LED module 30 can be higher. Color conversion particles 33 can also be deposited in the LED module 30 on the upper side of bonding wires 35, since the establishment process of the color conversion particles 33 is usually driven by gravity.
    For the LED module 30, a reverse color inhomogeneity over the emission angle of the light from the LED module 30 is observed as for the light from the LED module 20 of FIG. This is due to the fact that the LED chips 31 also have light from their uncovered ones
    Side faces is released. This light does not strike any color conversion particles 33 and is therefore not color converted either. Another problem with the LED module 30 is color
    Conversion particles 33, which settle in the areas between the LED chips 31 on the surface of the circuit board 32. There the color conversion particles 33 cannot contribute to the color conversion of the light emitted by the LED chips 31. Rather, it can even be that these color conversion particles 33 absorb light that has already been converted by other color conversion particles 33 and thereby generate unnecessary heat. Overall, the efficiency of the LED module 30 is adversely affected by these color conversion particles 33 between the LED chips 31.
    With regard to the LED module 30, at least one approach to the problem of color inhomogeneity is known, namely the attempt to reduce the light not converted by the LED chips 31 by adding scattering materials (such as BaSO4) for example as scattering particles on the LED chips 31 are applied. However, these scatter particles have the disadvantage that the total amount of light emitted by the LED module 30 is reduced. Another disadvantage of the LED module 30 is that the settlement process of the color conversion particles 33 takes a relatively long time during the manufacturing process, namely about four hours, so that it can also be ensured that the color conversion particles 33 are deposited on the LED chips 31 as desired.
    Another problem is that usually a color point of the light that a finished LED module 20 or 30 emits depends on the concentration and the amount of color conversion particles 23 or 33 that are distributed in the silicone matrix 24 or 34 . However, this also means that an individual mixture of color conversion particles 23 or 33 and material of the silicone matrix 24 or 34 must be provided for each desired color point. This disadvantageously entails a very high logistical effort. In addition, many individual mixtures harbor the risk of higher rejections of color conversion particles and matrix material.
    Another problem is that the color conversion particles 23 and 33 in the LED modules 20 and 30 are arranged purely randomly with one another and are therefore in particular mixed with one another. This is particularly disadvantageous when different types of color conversion particles, i.e. at least one first type of color conversion particles 23a or 33a, e.g. red color conversion particles, and a second type of color conversion particles 23b or 33b, e.g. green color conversion particles, can be used to create light mixtures, for example. Even if the different types of color conversion particles are provided one after the other in the manufacturing process, color conversion layers running horizontally (in a vertical sequence) are at best possible. Even this approach, however, cannot prevent some red color conversion particles from absorbing green light from green color conversion particles, which is only converted into heat and thus negatively affects the efficiency of the LED module 20 or 30.
    With regard to the above-mentioned disadvantages of the conventional LED modules 20 and 30, the present invention seeks to improve the prior art. In particular, it is the object of the present invention to provide a method for producing an LED module which has a more uniform light emission, in particular improved color homogeneity over the emission angle of the light from the LED module. Ideally, the aim is even perfect color homogeneity across the beam angle. The use of additional litter should be avoided. To this end, it is a particular aim of the present invention that all LED chips within the LED module are completely and uniformly coated with color conversion particles, in particular also on their side surfaces. In addition, the total amount of color conversion material required is to be reduced. The LED module should also be optimized in terms of its efficiency. The efficiency of the LED module is to be increased in particular by reducing unnecessary heat losses within the LED module. Another aim of the present invention is to make a color point of the light of the LED module produced adjustable without having to provide an individual mixture of the color conversion particles and the matrix material for each color point. Finally, it is also an aim of the present invention to reduce the duration of the settlement process of the color conversion particles during
    of the manufacturing process.
    [0011] The object of the invention is achieved by a method for producing an LED module or an LED module according to the independent claims. In order to achieve the object, the invention proposes, in particular, to support a step of coating LED chips of the LED module with color conversion particles by applying a voltage to at least the LED chips. The invention thus makes use of an electrical field-assisted chip-selective coating of the LED chips with color conversion particles. The dependent claims further develop the invention in an advantageous manner and in particular meet the above-mentioned endeavors of the present invention.
    The present invention specifically relates to a method for producing an LED module that has at least one LED chip, having the following steps: providing at least one LED chip on a preferably reflective carrier, providing color conversion particles electrically charged with a first polarity, preferably in a matrix material, charging the LED chip with a second polarity opposite to the first polarity, and applying the color conversion particles to the LED chip.
    By providing the two opposite polarities of the color conversion particles and the at least one LED chip (ie generating a voltage difference), an electric field is generated between the one or more LED chips of the LED module and the color conversion particles. In particular, it is important to electrostatically charge each LED chip relative to and in the opposite direction to the color conversion particles. As a result, the color conversion particles are attracted to the at least one LED chip and consequently both the top side of the LED chip and the side surfaces of the LED chip are coated. This means that the LED module emits a more even light during operation. In particular, the color of the light from the LED module is very homogeneous over its emission angle. The color inhomogeneity observed for conventional LED modules 20 or 30 is therefore eliminated or at least significantly reduced.
    In addition, by charging the at least one LED chip, the establishment process of the color conversion particles can be significantly shortened and only takes about an hour. Since the LED chip is also coated with color conversion particles on its side surfaces due to the polarity-related attraction of the color conversion particles, no additional scattering material is necessary. Overall, the efficiency of the LED module produced can also be significantly increased as a result.
    A potential is advantageously applied to at least one bonding wire of the LED chip for charging the LED chip.
    Thus, the corresponding polarity opposite to the polarity of the color conversion particles can easily be provided on the at least one LED chip. Since several LED chips are preferably connected in series on an LED module according to the invention, the same polarities can be applied to all LED chips simultaneously via the bonding wires. This results in an extremely uniform coating with color conversion particles over all the LED chips of the LED module and consequently also in an extremely uniform light emission from the LED module.
    The method advantageously furthermore has the following step: charging the preferably reflective carrier with a third polarity opposite to the second polarity.
    The reflective carrier is thus charged with a polarity which corresponds to the polarity of the color conversion particles provided. This creates a further electric field, namely between the carrier and the LED chips. The color conversion particles are repelled by the reflective carrier due to their same polarity. Due to the carrier charged with the reverse charge to the LED chip (which is, for example, a circuit board such as a PCB), the color conversion particles are displaced away from the
    free areas of the carrier between the LED chips and towards the side surfaces of the LED chips. No or at least significantly fewer color conversion particles are deposited between the LED chips, in particular in comparison to the LED module 20 of FIG. 2, so that on the one hand the amount of color conversion material used can be reduced and on the other hand it is also avoided. that the color conversion particles absorb already converted light and thereby generate heat. The heat losses within the LED module can therefore be reduced, which again increases the overall efficiency of the LED module.
    Advantageously, a plate arranged above the LED chip and the preferably reflective carrier are charged with differently high third polarity charges, preferably with a charge that changes over time, by an amount and / or a deposition form of the amount applied to the LED chip Adjust color conversion particles.
    [0020] Due to the different high charges and the quantity and / or deposit form of the color conversion particles that can be influenced thereby, the color homogeneity of the finished LED module can be finely adjusted via the emission angle. A small residual color homogeneity will namely also occur with an LED chip that is completely evenly covered. Through targeted adaptation by setting the various charges, i.e. as a result of the electric fields between the plate, for example a metal plate, and the LED chip as well as the carrier and the LED chip, almost perfect color homogeneity can be achieved over the beam angle. The carrier can be charged, for example, by charging a plate, for example a metal plate, arranged below the carrier and electrically connected to it.
    A first type of color conversion particles, preferably red color conversion particles, are advantageously provided with a higher charge of the first polarity and a second type of color conversion particles, preferably green color conversion particles, with a lower charge of the first polarity and the LED chip is charged with the second polarity , in particular with a charge of the second polarity that changes over time, in order to first apply the first type of color conversion particles and then the second type of color conversion particles to the LED chip.
    The loading of the LED chip and the different charges of the color conversion particles have the effect that the two types of color conversion particles are accelerated to different degrees towards the LED chip. As a result, a three-dimensional color conversion structure can be produced on the LED chip and around the LED chip. In particular, a first layer of the first type of color conversion particles directly on the top and the side walls of the LED chip and above that a second layer of the second type of color conversion particles also on the top and the side walls of the LED chip. In this way, it can be avoided, for example, that red color conversion particles absorb green light from green color conversion particles and generate unnecessary heat.
    The LED chip is advantageously charged in a controlled manner with a predetermined charge of the second polarity in order to produce an LED module that is suitable for emitting light of a predetermined color point.
    In particular, a height of the load, i. an intensity of the electric field between the LED chip and the provided color conversion particles. This makes it possible to check whether there are more or fewer color conversion particles on the LED chip. This allows the color point to be shifted depending on the applied charge. Thus, with a single mixture of color conversion particles and matrix material, different types of LED modules with different color points of the light they emit can be produced. As a result, both the waste of color conversion particles and matrix material and the logistical effort can be reduced.
    The invention also relates to an LED module that can be produced by a method as described above.
    An LED module produced in this way has properties which are clearly distinguishable from LED modules produced in a different manner (such as, for example, the LED modules 20 and 30 from FIGS. 1 and 2). In the following, these properties are referred to as the fingerprint of the LED module according to the invention. On the one hand, as fingerprints in the LED module according to the invention, both the side surfaces and the top of the at least one LED chip are coated with color conversion particles with an essentially uniform thickness. This is a direct consequence of the method described above, in particular the opposite polarities of the LED chips and the color conversion particles. Furthermore, bonding wires (if any) are coated with color conversion particles as a further fingerprint in the LED module according to the invention. In particular, the bond wires are covered to a certain extent with color conversion particles, i.e. at least also to a coating of the underside of the bonding wires. With conventional LED modules that use a gravity-driven settlement process for the color conversion particles, there is no coating on the underside.
    In an LED module according to the invention without bonding wires, for example when the LED chips are applied to the carrier by means of flip-chip technology, at least the substantially uniform coating of the top and the side surfaces of the at least one LED chip is observed as a fingerprint. This fingerprint cannot be achieved by a pure gravity-based settlement process, even when using a mask over the surfaces of the LED chips.
    Another fingerprint of the LED module can also be that different types of color conversion particles, for example red and green color conversion particles, are not mixed with one another, but a first layer of a first type of color conversion particles directly on the top and the side walls of the LED Chips is arranged and above, ie on this first layer, a second layer of a second type of color conversion particles is also arranged on the top and the side walls of the LED chip.
    The present invention also relates to an LED module, comprising a plurality of LED chips on a reflective carrier, wherein the top facing away from the carrier and the side surfaces of the LED chips are coated with at least one layer of color conversion particles, and the at least a layer on the top side facing away from the carrier and on the side surfaces of the LED chips has an essentially equal thickness.
    Due to the same thickness of the layer of color conversion particles on the top and on the side surfaces of the at least one LED chip, an extremely uniform light emission of the LED module is achieved, in particular a significantly reduced color inhomogeneity over the emission angle of the light from the LED module .
    Advantageously, the top side facing away from the carrier and the side surfaces of the LED chips are coated with at least one layer made of a first type of color conversion particles, preferably red color conversion particles, and then a layer made of a second type of color conversion particles, preferably green color conversion particles.
    This three-dimensional color conversion structure on the LED chips and around the LED chips can prevent, for example, red color conversion particles from absorbing green light originating from green color conversion particles and thereby generating unnecessary heat.
    [0033] The LED chips can advantageously be applied to the reflective carrier by means of flip chip technology.
    The present invention also relates to an LED module having a plurality of LED chips on a reflective carrier, the top side facing away from the carrier and the side surfaces of the LED chips being coated with at least one layer of color conversion particles, and the carrier has no color conversion particles in an interspace between the LED chips, such that the carrier is reflective in this interspace
    is.
    Because no color conversion particles are deposited in the spaces between the LED chips, less color conversion material can be used overall. This also avoids the occurrence of color conversion particles that do not contribute to color conversion or even cause undesired light absorption and heat generation. Finally, the partially exposed reflective carrier improves the emission efficiency of the LED module.
    Advantageously, the top side facing away from the carrier and the side surfaces of the LED chips are coated with at least one layer made of a first type of color conversion particles, preferably red color conversion particles, and then a layer made of a second type of color conversion particles, preferably green color conversion particles.
    This three-dimensional color conversion structure on the LED chips and around the LED chips can prevent, for example, red color conversion particles from absorbing green light from green color conversion particles and thereby generating unnecessary heat.
    Advantageously, the at least one layer of color conversion particles on the top side facing away from the carrier and on the side surfaces of the LED chips has essentially the same thickness.
    As a result, light from the LED module is emitted particularly uniformly and with no or hardly any color inhomogeneity over the emission angle of the light.
    Advantageously, the LED chips each have at least one bonding wire, which is also coated with color conversion particles.
    The side surfaces of the LED chips are advantageously coated essentially up to the point adjacent to the reflective carrier.
    Such a coating can be achieved in particular due to the interaction of gravity and electrostatic force, which is generated as described above by the polarities used in the manufacturing process. Due to the uniform coating right up to the edge of the carrier, a particularly uniform and efficient emission of the light from the LED module is achieved.
    [0043] The color conversion particles are advantageously provided in a matrix material, preferably in a silicone matrix.
    As a result, the color conversion particles deposited on the surfaces and side faces of the one or more LED chips are protected and fixed. For example, a later migration of the color conversion particles into the spaces between LED chips is avoided. Due to the electrostatic forces generated in the process of manufacturing the LED module according to the invention, the color conversion particles can otherwise migrate to the top and the side surfaces of the LED chips against a viscosity of the matrix material.
    The present invention also relates to an LED module having at least one LED chip on a reflective carrier, the top side facing away from the carrier and the side surfaces of the LED chip being coated with at least one layer of color conversion particles, and the LED Chip has at least one bonding wire, which is also coated with color conversion particles.
    Advantageously, the bonding wire is coated with color conversion particles on its underside.
    [0047] The bonding wire is advantageously encased by color conversion particles. The previously described coating or wrapping of the bonding wires with color conversion particles is a clear fingerprint of the LED module according to the invention.
    duls for the manufacturing process presented according to the invention.
    All of the above-described LED modules according to the invention solve the problem posed by the invention. In particular, uniform light emission with less color inhomogeneity of the emitted light over its emission angle is achieved for all LED modules according to the invention. The efficiency of these LED modules has also been increased.
    The present invention will now be described in detail below with reference to the accompanying figures.
    FIG. 1 shows a conventional LED module in which color conversion particles are evenly distributed in a silicone matrix.
    2 shows a conventional LED module in which color conversion particles are deposited within a silicone matrix on LED chips and a carrier surface.
    Fig. 3 shows an LED module according to the present invention.
    Fig. 4 shows a flow diagram of a manufacturing method according to the present invention.
    Fig. 5 schematically shows an LED module and its manufacturing method according to the present invention.
    Fig. 6 shows a photograph of an LED module according to the present invention.
    7 shows a microscopic image of an LED chip coated with color conversion particles in an LED module according to the present invention.
    8 shows a microscopic image of an LED chip coated with color conversion particles in an LED module according to the present invention.
    Fig. 9 shows an LED module according to the present invention.
    Figure 3 shows an LED module 10 according to the present invention. The LED module 10 was produced in particular with the presented method according to the invention.
    This method 100 is shown in FIG. In a first step 101 of the method 100, at least one LED chip is provided on a preferably reflective carrier. In a second step 102, color conversion particles electrically charged with a first polarity are provided, preferably in a matrix material. In a third step 103, the one or more LED chips is charged with a second polarity which is opposite to the first polarity. In a fourth step 104, the color conversion particles are applied to the at least one LED chip. The LED module 10 is thus produced by supporting a step of coating at least one LED chip of the LED module 10 with color conversion particles by applying a voltage to the LED chip.
    The LED chip can also be charged in a controlled manner with a predetermined charge of the second polarity in step 103 in order to specifically influence the color point of the light which the finished LED module 10 emits. If the intensity of the electric field between the LED chips 1 and the color conversion particles is also controlled via the set level of the charge, it can be influenced whether more or fewer color conversion particles are arranged on the LED chips 1 during step 104. As a result, the named color point of the LED module 10 can be shifted or defined as a function of the applied charge.
    The LED module 10 of FIG. 3 thus contains one or - as shown - several LED chips 1 which can be operated to emit light. For example, the LED chips 1 can be designed to emit blue light during operation. But it is also possible to have different types
    To build LED chips 1 in the LED module 10, which emit light of different colors or wavelengths. The LED chips 1 are applied to a carrier 2, for example a circuit board such as a PCB. A surface of the carrier 2 on which the LED chips 1 are applied is preferably reflective. The LED chips 1 in the LED module 10 are preferably contacted in series with bonding wires 5. Each LED chip 1 is preferably connected with at least two bonding wires 5. The LED chips 1 for operating the LED module 10 can be supplied with voltage and controlled via the bonding wires 5. During the manufacturing process 100 of the LED module 10, it is possible to charge the LED chips with the second polarity via the bonding wires 5.
    In the LED module 10, the LED chips 1 are arranged, in particular, within a dam 7. The dam 7 can at least partially enclose the LED chips 1, as indicated in FIG. 3, for example in a ring shape. To operate the LED module 10, at least two bonding wires 5 are led outside the dam 7 to at least two bonding pads 6. The bond pads 6 can also be connected directly or indirectly to an operating voltage source.
    Within the dam 7, the LED chips 1 are embedded in a matrix material 4, for example a silicone matrix. The LED module 10 is therefore preferably produced by means of the technology of dam and fill. The matrix material 4 is preferably fully transparent to the light from the LED chips 1 and protects the LED chips 1 and their coatings from external influences. Color conversion particles 3 are also provided in the matrix material 4. The color conversion particles 3 are in particular deposited on the surfaces facing away from the carrier 2 and on the side surfaces of the LED chips 1, each with a uniform thickness. This can be achieved by the method 100 according to the invention described above.
    The color conversion particles 3 can, for example, be phosphors which at least partially convert the wavelength of the light from the LED chips 1. If the LED chips 1 emit, for example, in the blue spectral range, then, for example, a color conversion material radiating in the yellow spectral range for the color conversion particles 3 can generate white light overall from the LED module 10. By appropriately choosing the color conversion material of the color conversion particles 3 and the type (emission wavelength) of the LED chips 1, different colors and color mixtures of the light emitted by the LED module 10 can be generated.
    It can also be seen in FIG. 3 that no color conversion particles 3 are deposited on the surface of the carrier 2 in the LED module 10 between the LED chips 1. In particular, the color conversion particles 3 are only deposited on and on the side of the LED chips 1. As a result, the carrier surface is exposed between the LED chips 1 and is preferably designed to be reflective, at least there, in order to support and optimize the coupling out of light from the LED module 10. As indicated by the arrows in FIG. 3, light emerges from each of the LED chips 1 during operation of the LED module 10 and then passes through a layer of color conversion particles 3 of approximately the same thickness, regardless of its emission angle. This ensures that from each LED -Chip 1 a very uniform, in particular, light of the same color is emitted. Overall, the uniformity of the light emitted by the LED module 10 during operation, in particular its color homogeneity, is thus significantly improved over the emission angle.
    It is also pointed out that color conversion particles 3 can also be deposited on the bonding wires 5, which connect the LED chips 1 of the LED module 10 to one another. The bonding wires 5 are even partially enveloped by color conversion particles 3.
    FIG. 5 shows the LED module 10 of FIG. 3 during the manufacturing process, in particular during the establishment process of the color conversion particles 3. To produce the color conversion coating of the LED chips 1, the color conversion particles 3 are first mixed, preferably in and with the matrix material 4, between the dam 7 and above
    the LED chips 1 metered. A viscosity of the matrix material 4 is preferably selected such that the color conversion particles 3 can be distributed in the matrix material 4 and migrate therein. Conventionally, a settlement process for the color conversion particles 3 would now begin, in which the color conversion particles 3 would be deposited purely by gravity on the surfaces of the LED chips 1 or of the carrier 2 before the matrix material 4 is cured.
    According to the invention, however, this establishment process is supported by charging the LED chips 1 with a polarity which is opposite to a polarity of the color conversion particles 3. The charging of the LED chips takes place - as shown in FIG. 5 - by applying a corresponding voltage to the LED chips 1. This means that at least one electric field is created between the LED chips 1 and the color conversion particles 3. This the establishment process is accelerated, since the color conversion particles 3 are attracted by the LED chips 1 and consequently are deposited on their upper sides facing away from the carrier 2 and their side surfaces.
    The carrier 2 is also advantageously charged by applying a voltage with a polarity which corresponds to the polarity of the color conversion particles 3 and which is opposite to the polarity of the charged LED chips 1. This is achieved, as shown in Fig. 5, by applying a voltage to a lower metal plate 8b. This lower metal plate 8b preferably makes flat contact with the carrier 2. As a result, sinking color conversion particles 3 are prevented from being deposited on the upper side of the carrier 2. In particular, the color conversion particles 3 are repelled from the top of the carrier, so that the coating of the side surfaces of the LED chips 1 is further supported and, above all, it is achieved that the layer on the top and on the side surfaces of the LED chips 1 is of uniform thickness. In addition, it is promoted that the color conversion particles 3 are completely or largely displaced from the top of the carrier 2 between the LED chips 1 and between the outermost LED chips 1 and the dam 7. These color conversion particles 3 are then pushed towards the side surfaces of the LED chips 1 and are deposited there due to the applied voltage. As a result, the spaces on the top of the carrier remain largely free of color conversion particles 3 and preferably form reflective surfaces.
    Advantageously, an upper metal plate 8a attached above the LED module 10 is also charged by applying a voltage with a polarity that corresponds to the polarity of the color conversion particles 3 in order to urge them in the direction of the LED chips 1 and the establishment process 3 to accelerate the color conversion particles 3 further.
    As shown in FIG. 5, a voltage U + generated by a voltage source 9 is advantageously applied to the upper metal plate 8a and to the lower metal plate 8b. A voltage U- generated by preferably the same voltage source 9 is applied to the LED chips 1 via the bond pads 6 and the bond wires 5. Due to the voltage difference (U + U-), an electrical field builds up between the upper metal plate 8a and the top of the LED chips 1, which forces the charged color conversion particles 3 towards the LED chips 1. As a result, the settlement process of the color conversion particles 3 is accelerated and the color conversion particles 3 are deposited on the upper sides and the side surfaces of the LED chips 1. Due to the same voltage difference, an electric field also builds up between the lower metal plate 8a and the LED chips 1, which forces the charged color conversion particles 3 to the side surfaces of the LED chips 1 and thereby prevents the color conversion particles 3 from settling on the surface of the carrier 2 accumulate.
    The voltage difference (U + - U-) between the metal plates 8a, 8b and the LED chips 1 is preferably between 20-100 V, more preferably between 40-80 V, even more preferably at 60 V. Furthermore, a distance is d between the upper metal plate 8a and the upper side of the dam 7 or the surface of the filled matrix material 4, preferably between 1-5 mm, more preferably 3 mm. As already described, the lower metal plate 8b preferably lies flat against a lower surface of the carrier 2.
    The upper metal plate 8a and the lower metal plate 8b with different
    Lich high charges, achieved by different high voltages U + or U-, can be charged. This means that the electrical fields between the metal plates 8a, 8b and the LED chips 1 can each be set in a targeted manner, preferably even variable over time. As a result, an amount and / or a form of deposition of the color conversion particles on the upper sides or side surfaces of the LED chips 1 can be fine-tuned, in particular also slightly inhomogeneous over the course of the upper side and / or the side surfaces of the LED chips 1. As a result, the color homogeneity of the finished LED module 10 can be improved again. In particular, by setting the charges appropriately, it is also possible to perfect the color homogeneity over the emission angle. Incidentally, the carrier 2 could also have a direct voltage applied to it in order to charge it.
    FIG. 6 shows a photograph of an LED module 10 according to the present invention in plan view. The dam 7, which runs around a large number of LED chips 1 and encloses them in an inner area, can be clearly seen. The LED chips 1 are encapsulated within the dam 7 with a matrix material 4 and coated with color conversion particles 3 on their upper sides facing away from the carrier 2 and their side surfaces.
    However, spaces between the LED chips 1 are not coated with color conversion particles 3, so that the surface of the carrier 2 that is reflective here is exposed and can be clearly seen in FIG. 6.
    7 shows a microscopic image of a cross section through an LED chip 1 of the LED module 10. The LED chip 1 is arranged on the carrier 2 and contacted with at least one bonding wire 5. On the surface of the LED chip 1, which faces away from the carrier 2, or on its side surfaces, a continuous layer of color conversion particles 3 is formed with an approximately uniform thickness over its entire course. Besides the LED chip 1, i.e. There are no color conversion particles 3 on the surface of the carrier 2. Instead, there are color conversion particles 3 both on the top and on the underside of the bonding wire 5, i.e. this bonding wire 5 is coated with color conversion particles 3. The color conversion particles 3 and the LED chip 1 are enclosed by a matrix material 4. 7 thus shows a unique fingerprint of the LED module 10 according to the present invention, which was produced by the method 100 according to the invention. The fingerprint here is in particular the uniformly thick coating of both the side faces and the surface of the LED chip 1 and, moreover, the wrapping of the bonding wire 5 with color conversion particles 3.
    8 also shows a microscopic image of an LED chip 1 in an LED module 10 according to the present invention. In particular, FIG. 8 shows that no or almost no color conversion particles 3 are deposited on the surface of the carrier 2 between two LED chips 1 of the LED module 10. For this purpose, the color conversion particles 3 are deposited with a uniform thickness on both the upper sides of the LED chips 1, which face away from the carrier 2, and their side surfaces.
    9 shows another LED module 10 of the present invention. The LED module 10 of FIG. 9 is similar to the LED module 10 of FIG. 3. The only difference in FIG. 9 is that several types of color conversion particles 3, in particular a first type of color conversion particles 3a and a second type of color conversion particles 3b during of the manufacturing method shown in FIG. 4 were provided. The first type of color conversion particles 3a has a higher charge of the first polarity and preferably consists of red color conversion particles. The second type of color conversion particles 3b has a lower charge of the first polarity and preferably consists of green color conversion particles.
    In the LED module 10 of FIG. 9, the top side facing away from the carrier 2 and the side surfaces of the LED chips 1 are thus provided with a first layer made of the first type of color conversion particles 3a and on top of that a second layer made of the second type coated by color conversion particles. The different types of color conversion particles 3a, 3b are therefore not mixed with one another. The first layer is right on top and on the side
    Walls of the LED chips 1 arranged, while the second layer is arranged over and on the first layer (but also on the top and the side walls of the LED chips 1). A three-dimensional color conversion structure is thus formed on the LED chips 1 and around the LED chips 1. This prevents, for example, red color conversion particles from absorbing green light originating from green color conversion particles and generating unnecessary heat in the process. It is also possible to use more than two layers and more than two types of color conversion particles 3a, 3b.
    Overall, the method 100 of the present invention can be used to produce an LED module 10 that has a significantly more uniform light emission, in particular a significantly improved color homogeneity over the emission angle of the light from the LED module 10 than is the case with conventional LED modules, for example as is the case with the LED modules 20 and 30 from FIGS. This is mainly due to the fact that the LED chips 1 of the LED module 10 are coated uniformly on their side surfaces and surfaces facing away from the carrier 2. The color homogeneity can be optimized by specifically charging the plates 8a, 8b. The efficiency of the LED module 10 according to the invention can be increased overall, especially since there are no color conversion particles 3 between the LED chips 1, whereby on the one hand the reflective surface of the carrier 2 is exposed and on the other hand no color conversion particles 3 merely cause light absorption and heat generation . The heat generation can in particular also be reduced in LED modules 10 with different types of color conversion particles, in that discrete color conversion layers, each consisting of a single type of color conversion particles, are formed on the LED chips 1 through different charges of the color conversion particles and variable charging of the LED chips 1 during the manufacturing process will.
    The production of the LED module 10 of the present invention can also be significantly accelerated, since in particular the settlement process of the color conversion particles 3 is generated due to the support of electrical fields by applying a corresponding potential to at least the LED chips 1 and preferably the carrier 2 is accelerated. This also makes the LED modules 10 of the present invention significantly more cost-effective in mass production. The fact that overall less color conversion material has to be used to coat the LED chips 1, since the color conversion material is optimally and efficiently only deposited on the LED chips 1, also helps to reduce the manufacturing costs. It is also advantageous that by specifically adjusting the charge of the LED chip 1 during the manufacturing process, different types of LED modules with different color points can be produced, which further reduces the amount of color conversion material used due to lower scrap.
    权利要求:
    Claims (17)
    [1]
    1. Method (100) for producing an LED module (10), the at least one LED chip
    (1), comprising the following steps:
    - Providing (101) at least one LED chip (1) on a preferably reflective carrier (2),
    - providing (102) color conversion particles (3) electrically charged with a first polarity, preferably in a matrix material (4),
    - Charging (103) the LED chip (1) with a second polarity opposite to the first polarity, and
    - Application (104) of the color conversion particles (3) to the LED chip (1).
    [2]
    2. The method (100) according to claim 1, wherein a potential is applied to at least one bonding wire (5) of the LED chip (1) for charging (103) the LED chip (1).
    [3]
    3. The method (100) according to one of claims 1 and 2, further comprising the following step: - charging the preferably reflective carrier (2) with a third polarity opposite to the second polarity.
    [4]
    4. The method according to claim 3, wherein a plate (8a) arranged above the LED chip (1) and the preferably reflective carrier (2) are charged with charges of third polarity of different levels, preferably with a charge that changes over time, by one Set the amount and / or a deposition form of the color conversion particles (3) applied to the LED chip (1).
    [5]
    5. The method (100) according to any one of claims 1 to 4, wherein a first type of color conversion particles (3a), preferably red color conversion particles, with a higher charge of the first polarity and a second type of color conversion particles (3b), preferably green color conversion particles, with a lower charge of the first polarity are provided, and the LED chip (1) is charged with the second polarity, in particular with a charge of the second polarity that changes over time, in order to first generate the first type of color conversion particles (3a) and then the second type of Apply color conversion particles (3b) to the LED chip (1).
    [6]
    6. The method (100) according to any one of claims 1 to 5, wherein the LED chip (1) is charged in a controlled manner with a predetermined charge of the second polarity in order to produce an LED module that is suitable for emitting light of a predetermined color point.
    [7]
    7. LED module (10), comprising several LED chips (1) on a reflective carrier (2), the top side facing away from the carrier (2) and the side surfaces of the LED chips (1) with at least one layer Color conversion particles (3) are coated, and the at least one layer on the top side facing away from the carrier (2) and on the side surfaces of the LED chips (1) has the same thickness.
    [8]
    8. LED module (10) according to claim 7, wherein the top side facing away from the carrier (2) and the side surfaces of the LED chips (1) with at least one layer of a first type of color conversion particles (3a), preferably red color conversion particles, and a layer of a second type of color conversion particles (3b), preferably green color conversion particles, is coated thereon.
    [9]
    9. LED module (10), comprising several LED chips (1) on a reflective carrier (2), the top side facing away from the carrier (2) and the side surfaces of the LED chips (1) having at least one layer Color conversion particles (3) are coated, and the carrier (2) has no color conversion particles (3) in a space between the LED chips (1) and the carrier (2) is reflective in this space.
    [10]
    10. LED module (10) according to claim 9, wherein the top facing away from the carrier (2) and the side surfaces of the LED chips (1) with at least one layer of a first type
    of color conversion particles (3a), preferably red color conversion particles, and thereon a layer of a second type of color conversion particles (3b), preferably green color conversion particles.
    [11]
    11. LED module (10) according to claim 9 or 10, wherein the at least one layer of color conversion particles (3) on the top facing away from the carrier (2) and the side surfaces of the LED chips (1) has the same thickness.
    [12]
    12. LED module (10) according to one of claims 9 to 11, wherein the LED chips (1) each have at least one bonding wire (5) which is also coated with color conversion particles (3).
    [13]
    13. LED module (10) according to one of claims 9 to 12, wherein the side surfaces of the LED chips (1) are coated to adjoin the reflective carrier (2).
    [14]
    14. LED module (10) according to one of claims 9 to 13, wherein the color conversion particles (3) are provided in a matrix material (4), preferably in a silicone matrix.
    [15]
    15. LED module (10), comprising at least one LED chip (1) on a reflective carrier (2), the top side facing away from the carrier (2) and the side surfaces of the LED chip (1) having at least one layer are coated from color conversion particles (3), and the LED chip (1) has at least one bonding wire (5) which is also coated with color conversion particles (3).
    [16]
    16. LED module (10) according to claim 15, wherein the bonding wire (5) is coated on its underside with color conversion particles (3).
    [17]
    17. LED module (10) according to one of claims 15 and 16, wherein the bonding wire (5) is enveloped by color conversion particles (3).
    In addition 9 sheets of drawings
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    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US6924233B1|2004-03-19|2005-08-02|Agilent Technologies, Inc.|Phosphor deposition methods|
    US20080150416A1|2006-11-28|2008-06-26|Dowa Electronics Materials Co., Ltd.|Light-emitting device and manufacturing method thereof|
    EP2573828A2|2011-09-26|2013-03-27|Toshiba Lighting & Technology Corporation|Manufacturing method for light-emitting device and the light-emitting device|
    DE102011056813A1|2011-12-21|2013-06-27|Osram Opto Semiconductors Gmbh|Method for producing a light-emitting diode|
    US20140048824A1|2012-08-15|2014-02-20|Epistar Corporation|Light-emitting device|
    JP5442554B2|2010-07-22|2014-03-12|シチズンホールディングス株式会社|Manufacturing method of light emitting diode|
    JP2013153082A|2012-01-25|2013-08-08|Sharp Corp|Light-emitting diode module, and manufacturing method of light-emitting diode module|
    DE102012208900A1|2012-05-25|2013-11-28|Osram Opto Semiconductors Gmbh|Method for producing optoelectronic components and apparatus for producing optoelectronic components|
    DE102013207226A1|2013-04-22|2014-10-23|Osram Opto Semiconductors Gmbh|Production of a Layer Element for an Optoelectronic Semiconductor Chip|DE102016206927A1|2016-04-25|2017-10-26|Tridonic Jennersdorf Gmbh|Method for producing an LED module|
    DE102018111610A1|2018-05-15|2019-11-21|Osram Opto Semiconductors Gmbh|Optoelectronic lighting device, bonding wire and method for producing an optoelectronic lighting device|
    CN111697120A|2020-07-10|2020-09-22|佛山市国星光电股份有限公司|LED device, packaging method thereof and LED lamp|
    法律状态:
    2021-12-15| MM01| Lapse because of not paying annual fees|Effective date: 20210430 |
    优先权:
    申请号 | 申请日 | 专利标题
    DE102015207898|2015-04-29|
    PCT/AT2016/050114|WO2016172753A1|2015-04-29|2016-04-27|Method for producing an led module|
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