RU2514055C1 - Method of arranging and connecting light-emitting elements in bunches, arranged in monolithic light-emitting arrays - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: method according to the invention involves arranging light-emitting elements in a closed field in repeating groups with virtual numbers of bunches within a group, first in forward order and then in reverse order. Series connection of light-emitting elements with like light-emitting elements within a group is carried out, for example, from the right-hand side, and between neighbouring groups on the left-hand side, with alternately adjacent conductors directed in parallel to the axis of the position of the light-emitting element in the closed field if the conductor is placed in the plane of the closed field. In case of multi-level connection of the light-emitting element under the plane of the light-emitting element of the conductor in insulating layers, the light-emitting element is connected by a connecting metal coating through the insulating layers with the corresponding conductor on the insulating layers situated on two virtual non-crossing lines on which, for example, on the left-hand side, connection with the light-emitting element is carried out within the group of light-emitting elements, and on the right-hand side between neighbouring groups in areas without conductors in previous insulating layers. The invention enables to find ways to arrange and connect bunches of light-emitting elements in an integrated circuit array thereof in order to increase density of arrangement, maintain emission of the light-emitting device when one or more bunches of the light-emitting array break down in manufacturing processes, inspection, classification, operation, and high yield of non-defective items.

EFFECT: high density of arranging groups of light-emitting elements in an integrated circuit array, invariable form of emission of the light-emitting device when one or more groups break down, reliability of the light-emitting array in manufacturing processes, inspection, classification and operation.

2 cl, 16 dwg

Description

The invention relates to the manufacture of light emitting devices, in particular to the production of integrated light emitters.

Light sources based on electroluminescent diodes (LEDs) are widely used in technology where small-sized, high-efficiency light sources with high radiation power are required. Sources of radiation with such parameters can be made in the form of a multi-element emitting device in which individual light-emitting elements (LEDs) are interconnected in series (in garlands) or in parallel. The serial connection of the radiating elements allows you to effectively use the power of the power source. Parallel connection of radiating elements or links from series-connected elements (garlands) provides the ability to create light sources with a given output light power.

A positive effect of the integration of groups of crystals into one structure with their parallel inclusion inside the structure (one crystal) is an increase in the steepness of the current-voltage characteristics of such structures, a decrease in direct voltage and the total consumption of electric power, due to which the lumen / watt ratio increases, t. e. the energy of the luminous flux improves (Components and Technologies, No. 7, 2005, “Why LEDs Do Not Always Work the Way Their Manufacturers Want”).

Currently known series-parallel matrix connection of LEDs (Electronic components, No. 8, 2009, pp. 42-43, "Mean Well LED power supplies"), designed for discrete or hybrid connection of LEDs. In the above scheme of parallel connection of garlands, chains with the same certain number of the number of series-connected LEDs, the disadvantages of this connection method are indicated due to the difference in the total values of the voltage drop of the LEDs at the current set through them. As a result, some garlands glow brightly, others glow dimly. You can get rid of this drawback or reduce it only if all the garlands of LEDs are manufactured in a single technological cycle, i.e. in integral performance.

The placement of light-emitting cells and their connections in integral form at the design stage in the manufacture of various stencils required in the technological cycle. In this process, crystalline layers are grown on a substrate, then various sputtering and selective etching are performed to obtain the desired properties of the light-emitting elements and their interconnections in all the numerous matrices of light-emitting elements on the initial substrate, followed by cutting it into finished matrices. However, although the uniform manufacturing cycle reduces the number of failures of elements and compounds in the finished light-emitting matrix, due to various defects in the materials used and technological errors when combining masks, they do arise during sputtering and etching. As a result, this leads to the failure of the functioning of individual garlands.

Known patent RU 2426200 C1, H01L 33/00, dated 03/15/2010 "Method for the formation and verification of LED matrices", in which the garlands of LED cells are placed on a substrate in concentric fields. This method of placing garlands in the event of failure of one or more preserves the radiation of the light-emitting device, however, there is a problem of parallel connection of garlands of radiating elements in large closed concentric fields of the light-emitting matrix, which does not allow efficient use of the substrate area.

Known patent RU 2465683 C1, H01L 25/13, dated 9/08/2011 "Method for the formation of light-emitting matrices", in which garlands with a certain number of series-connected light-emitting elements in an integral field in sequential from the center closed rectangular or square fields of light-emitting elements. If this quantity does not correspond to the multiplicity, then its remainder or arrears are transferred or carried from neighboring rectangular fields that are redundant in number of light-emitting elements, slightly altering the boundaries of adjacent fields. The formed garlands of light-emitting elements are placed in the fields in groups or in alternating sequence between each other and connect all the garlands in parallel.

This method of garland placement in the event of failure of one or more preserves the radiation of the light-emitting device, however, there is a problem of parallel connection of the garlands of radiating elements in large closed rectangular or square fields of the light-emitting elements of the light-emitting matrix, which does not allow efficient use of the substrate area.

The closest in technical essence and the achieved result is RU 2295174 C2, 10.10.2005, “Light-emitting device containing light-emitting elements” (prototype). In this device, a plurality of light-emitting elements are molded integrally on one square substrate. Light-emitting elements are connected in series in garlands to the contact pads of their power supply and placed on a substrate in a zigzag fashion. This method allows you to place only no more than two garlands and if at least one garland fails during the manufacturing process, it does not allow the light-emitting device to function properly. In addition, the cross-connection of garlands also reduces the reliability of the product and does not allow the formation of many parallel-connected garlands.

The objective of this invention is to find methods of placement and connection of garlands of light-emitting elements in their integrated matrix to increase the density, preservation of radiation of the light-emitting device in case of failure of one or more garlands of light-emitting matrix in the manufacturing process, verification, classification, operation and, accordingly, increasing the yield products.

EFFECT: provision by placement and connection of light-emitting elements of a light-emitting matrix, the maximum possible density of placement of parallel-connected alternating garlands of light-emitting elements in large concentric or square fields of the substrate for a given voltage drop across the garlands, elimination of intersection of serial connections of light-emitting elements in the garlands, maintaining the functioning of the light-emitting matrix in manufacturing, inspection, classification processes and, operation.

The problem is achieved in that in the field of light-emitting elements in a square or rectangular matrix of light-emitting elements, preferably square, they ensure that intersections of successive connections of light-emitting elements in successively alternating garlands in closed fields are prevented by sequentially placing alternating groups of light-emitting elements equal to the number of garlands in a closed concentric or rectangular field with virtual numbers of each garland x elements, in each group the light-emitting elements are placed in the direct, then in the reverse order, and serial connections are made with the same numbers of the elements of the groups alternately from the left and right sides of the connection of the light-emitting elements in the case of connecting the light-emitting elements in one plane, in the case of multilevel connection with metallized ones conductors on a substrate in insulating layers under the light emitting elements connecting conductors in each plane under each light emitting element By the way, their connection paths are carried out along two disjoint lines, and the vertical connections of the conductors with light-emitting elements through the insulating layers are carried out in zones of absence of conductors in the previous layers.

Figure 1 shows an example of the formation of concentric fields according to patent RU 2426200, in which light-emitting elements are placed in concentric fields by alternating groups of light-emitting elements arranged in a direct order. For readability, odd fields are highlighted with different dimming.

Figure 2 shows an example of connecting light-emitting elements in one plane in one of the concentric fields of the patent RU 2426200 or rectangular fields of the patent RU 2465683 in a direct order. Intersections of series-connecting light-emitting elements of conductors are eliminated by air jumpers.

Figure 3 shows an enlarged fragment of figure 2, showing the width of the field of placement of garlands of light-emitting elements and an idea of the cross section of the connecting conductors.

Figure 4 shows an example of a direct connection of the light-emitting elements on the insulating layer under the light-emitting elements.

Figure 5 shows an enlarged fragment of figure 4, showing a view of the cross section of the connecting conductors.

Figure 6 shows an example of a direct connection of light emitting elements on four insulating layers below the light emitting elements.

Fig.7 shows an enlarged fragment of Fig.6, showing a view of the cross section of the connecting conductors in the presence of technological holes in them.

On Fig the proposed method shows an example of the connection of the light-emitting elements in one plane, first in the forward, then in the reverse order.

Fig.9 shows an enlarged fragment of Fig.8, showing the width of the field of placement of garlands of light-emitting elements and an idea of the cross section of the connecting conductors.

Figure 10 on the proposed method shows an example of the formation of compounds of light-emitting elements in four insulating layers under the light-emitting elements using virtual left and right planes, passed through the left and right connecting light-emitting elements conductors.

11, the proposed method shows an example of connections of light-emitting elements in four insulating layers under the light-emitting elements.

On Fig shows an enlarged fragment of 11, showing a view of the cross section of the connecting conductors.

13 shows an example of a connecting wiring of light-emitting elements in one plane for a concentric light-emitting matrix of seven concentric fields. In it, light emitting elements are placed in concentric fields in alternating groups of light emitting elements. The light-emitting elements within the groups corresponding to the number of garlands in the concentric field are placed first in the direct, then in the reverse order.

On Fig shows a similar example of the connecting wiring of the light-emitting elements in one plane for a rectangular light-emitting matrix of seven rectangular fields. In it, light emitting elements are placed in rectangular fields by alternating groups of light emitting elements. The light-emitting elements within the groups corresponding to the number of daisies in a rectangular field are placed first in the direct and then in the reverse order.

On Fig shows the same concentric light-emitting matrix of seven concentric fields depicted in Fig, in which the wiring of the compounds according to the proposed method is carried out in insulating layers under the light-emitting elements. It allows you to compare the efficiency of the use of the allocated areas for light-emitting elements on the substrate of the light-emitting matrix.

On Fig shows the same rectangular light-emitting matrix of seven concentric fields depicted in Fig, in which the wiring of the compounds according to the proposed method is carried out in insulating layers under the light-emitting elements. It also allows you to compare the efficiency of the use of the allocated areas for light-emitting elements on the substrate of the light-emitting matrix.

The method is as follows. In the methods of patents RU 2426200, for example, FIG. 1 and RU 2465683, the number of the closed field of 3-i light-emitting elements 4 increasing from the center 1 of the matrix 2 increases the number of parallel-connected garlands of 3-ij series-connected light-emitting elements of the same name 4, where i is the number of the closed field from the center of matrix 2, aj is the number of garlands in a closed field 3-i. To maintain a uniform distribution of radiation throughout the light emitting matrix 2 in the event of failure of some garlands 3-i-j, the light emitting elements 4 need to be placed in alternating groups 5 with the number of light emitting elements 4 equal to the number of placed garlands 3-i-j in a closed field 3-i. In this case, if the light-emitting elements 4 in groups 5 are placed in the direct order, Fig. 2, then the problem arises of connecting the same-emitting light-emitting elements 4 without intersections of the conductors 6, for example, “air” jumpers 7, FIG. 2, and the number of conductors 6 at placed on the substrate 8 in the same plane 9. Fig. 3 shows a sectional view of an enlarged fragment 10, from which it can be seen that the width 11 of the area occupied by the garlands 3-i is determined by the number of conductors 6, the size of the light-emitting element 4 and the conductor 12 connecting the lights the radiating element 4 with the most remote conductor 6, placed parallel to the placement of the light-emitting elements 4 in the garlands 3-i. Another problem arises with the multilevel placement of conductors 6 in insulating layers 13 singing with light-emitting elements 4, FIG. 4, FIG. 7, in volumes limited by their sizes. In particular, reducing the cross-sectional size of the conductors 6 with an increase in their number, FIG. 4, leads to an unacceptable increase in the ohmic resistance of the conductors 6. For example, FIG. 5 shows an enlarged fragment 14 cut out of FIG. 4, in which the conductors 6-j-1 and 6-j-2 are connected through an insulating layer 13-0 by connecting metallization 15-1 and 15-2, for example, with the anode and cathode of the light-emitting element 4-2-k, where k is the number of the light-emitting element 4 in the garland 3-ij on the moment of its connection.

A similar disadvantage occurs when laying 6-j conductors in the multilayer insulating layers 13-j, (Fig.6), connected in series through holes 16-1-l, 16-2-m, 16-3-n in the conductors 6 on the previous insulating layers 13 with corresponding light emitting elements 4 of garlands 3-i, where l is the number of holes in the conductor 6-1-j, m is in the conductor 6-2-j, n is in the conductor 6-3-j. Due to the uneven number of holes 16 in the conductors 6 in the insulating layers adjacent to the light emitting elements 4, a difference in ohmic resistances arises in the conductors 6, which, ultimately, leads to a difference in currents in the 3-ij garlands and, accordingly, to an uneven glow of the garlands 3-ij. For example, FIG. 7 shows an enlarged fragment 17 cut from FIG. 6, in which the conductors 6 are connected through insulating layers 13-j by connecting metallization 15-1 and 15-2 to the light emitting element 4-4-k.

As can be seen from figure 2-7, these methods of placing light-emitting elements 4 on the substrate 8 lead to a complication and increase in the number of technological operations, to an unjustified increase in the passive area for laying conductors 6 and 12, if they are placed in the same plane 9 of the substrate 8 , and also to increase the ohmic resistance when laying the conductors 6 and 12 in the insulating layers 13 under the area of the light emitting elements 4 due to a decrease in the cross section of the conductors 6.

A completely different picture arises if, in the field 3-i, the placement of light-emitting elements 4 and their groups 5 of garlands 3-ij is carried out on the plane 9 of the substrate 8 by alternating in a straight line, then in the reverse order of the light-emitting elements 4 of the corresponding garlands 3-ij in groups 5, FIG. .8. In this case, consecutive connections by conductors 6 and 12 alternating first, for example, on the left, then on the right, of the same light-emitting elements 4 in groups 5 of garlands 3-ij in a concentric or rectangular field 3-i never intersect with other connections in groups 5. However, in the case of placing them in the same plane 9 of the substrate 8, although there are no intersections of the conductors 6 and 12, this technique of placing light-emitting elements 4 on the substrate 8 also leads to an increase in the passive area for laying conductors 6 and 12 and is justified when a small number of garlands j in field 3-i. Fig. 9 shows an enlarged fragment 18 cut out of Fig. 8, from which it can also be seen that the width 11 of the area of the plane 9 occupied by the garlands 3-i is determined by the number of conductors 6, the sizes of the light-emitting element 4 and the conductor 12 connecting the light-emitting element 4- jk with the most remote conductor 6 placed parallel to the placement of the light-emitting elements 4 in the garlands 3-i. This drawback can also be avoided if this technique is applied under the light-emitting elements 4 in volumes limited to their sizes in a multilevel arrangement of conductors 6 and 12 in insulating layers 13, Fig. 11.

For this, in Fig. 8, through conductors 6-j located at the same distance from the line of location of the light-emitting elements 4 of the closed field 3-i, virtually to the left, 6-4-pl, 6-3-pl, 6-2-pl, 6- 1-pl, and on the right, 6-4-pp, 6-3-pp, 6-2-pp, 6-1-pp, draw the corresponding planes, Fig. 10, which then each, left and right, are combined into one and placed under the plane 9 with light emitting elements 4. As a result, j planes are formed under the plane of placement of the light emitting elements 4, in this case insulating layers 13-j, on which conductors 6-j are placed on the nep intersecting left and right virtual lines of the laying of conductors 6-j in the insulating layers 13-j, Fig.11. Or, in another way, for error-free connection of light-emitting elements 4 with conductors 6-j in insulating layers 13-j along the left and right virtual lines of plane 9, Fig. 8, with conductors 6-j and 12-j placed on it connecting light-emitting elements 4 in one plane 9, they are bent along the axis of arrangement of the light-emitting elements 4 in a closed field 3-i until they are aligned with the insulation width, 11, between the left and right conductors 6-j and parallel planes 13-j are drawn, equal to the number of garlands j of light-emitting elements 4 in a closed field 3-i, in which place the insulating layers 13-j with left and right conductors 6-j-l and 6-j-p.

Next, carry out the following operations. For the first garland 3-1-1, conductor 6-1-1 on the insulating layer 13-1 on the right side of its plane by connecting metallization 15-1-1 (hereinafter in FIG. 11 due to loss of readability, their numbering is omitted) through an insulating junction 13-0 are connected, for example, to the anode of the first light-emitting element 4-1-1, its cathode is connected by metallization 15-1-2 through the insulating layers 13-0, 13-1, 13-2, 13-3 connected to the conductor 6- 1-2 on the insulating layer 13-4 on the left side of its plane. The conductor 6-1-2 is connected by connecting metallization 15-1-3 through the insulating layers 13-3, 13-2, 13-1, 13-0 with the anode of the next second light-emitting element 4-1-2. The cathode of this light-emitting element 4-1-2 through the insulating layer 13-0 by connecting metallization 15-4 is connected to the conductor 6-1-3 on the insulating layer 13-1 again on the right side of its plane. Next, the process of sequential connection of the same light-emitting elements 4-1-k for this garland 3-i-1 is repeated. For the second garland 3-i-2, the conductor 6-2-1 on the right side through the connecting metallization through the insulating layers 13-1 and 13-0 is connected to the anode of the first light-emitting element 4-2-1. The cathode of the light-emitting element 4-2-1 by connecting metallization through the insulating layers 13-0, 13-1, 13-2 by connecting metallization, a conductor 6-2-2 on the left side on the insulating layer 13-3, connecting metallization through the insulating layers 13- 2, 13-1, 13-0 are connected to the anode of the next second light emitting element 4-2-2. The cathode of the light-emitting element 4-2-2 by connecting metallization through the insulating layers 13-0, 13-1 by connecting metallization, a conductor 6-2-3 on the right side on the insulating layer 13-2, connecting metallization through the insulating layers 13-1, 13- 0 are connected to the anode of the next third light emitting element 4-2-3. Next, the process of sequential connection of the same light-emitting elements 4-2-k for this garland 3-1-2 is repeated. A similar procedure is performed for the following garlands 3-i-3 and 3-i-4, sequentially connecting the corresponding light-emitting elements 4-3-k and 4-4-k. 6-jk conductors are laid for 3-i-1 garland alternately on insulating layers 13-1 and 13-4, for 3-i-2 garland on insulating layers 13-2 and 13-3, for 3-1-3 garland on insulating layers 13-3 and 13-2, for garland 3-i-4 on insulating layers 13-4 and 13-1.

From Fig. 11, we notice that in the field 3-i, due to the variable placement of the 6-jk conductors on the left and right sides on the insulating layers 13-i and the variable placement in the insulating layers 13-1 themselves, given the initial placement order, direct and the reverse order of the light-emitting elements 4 and their series connection in groups 5 in the field 3-i is not allowed to overlap when laying them. In addition, Fig. 12, the cross section of the placed conductors 6-j-k does not depend on the number of daisies in the field 3-i.

On Fig and Fig.14 shows examples of the placement and serial connection of the light-emitting elements 4 to the supply busbars 20 and 21 by conductors 6 in the same plane in the matrices 2 on the substrates 8, respectively, to seven concentric and rectangular fields with a maximum number of garlands in the last field equal to four. As you can see, a further increase in the number of fields will lead to a further decrease in the size of the light emitting elements 4 due to the requirements for the permissible cross section of the conductors 6 and the distance between these conductors.

On Fig and Fig shows the same examples of placement and serial connection of the light-emitting elements 4 to the supply busbars 20 and 21 of the conductors 6, but when placed under the light-emitting elements 4 in the insulating layers 13. This arrangement does not limit the number of fields 3 and, respectively the number of garlands j in the last field 3 of the placement of light-emitting elements 4 in the matrices 2 on the substrates 8 and allows, with appropriate methods for placing the light-emitting elements 4, to maximize the use of the area of the substrate 8.

Literature

1. RU 2426200 C1, H01L 33/00, dated 03.03.2010 “Method for the formation and verification of LED matrices”.

2. RU 2465683 C1, H01L 25/13, dated 9.8 2011 “Method for the formation of light-emitting matrices”.

3. RU 2295174 C2, 10.10.2005, “Light-emitting device containing light-emitting elements” (prototype).

4. Components and technologies, No. 7, 2005, “Why LEDs do not always work the way their manufacturers want.”

5. Electronic Components, No. 8, 2009, pp. 42-43, “Mean Weil LED Power Supplies”.

6. RU 2012090, 05/22/1991, “A method of forming interconnects in a matrix of three-dimensional semiconductor elements”.

7. RU 2034363, 11.17.1992, “Method for the manufacture of electrically conductive transparent films”.

8. RU 2359356, 11.26.2007, “A method for creating conductive nano-wires on semiconductor substrates”.

9. RU 2399986, January 16, 2009, “A method for manufacturing a transparent ohmic contact structure of BeO / Au / Beo / h-GaN”.

10. RU 2416135, 10.25.2007, “A semiconductor element, a method of manufacturing a semiconductor product and a matrix of light emitting diodes obtained using this manufacturing method”.

Claims (2)

1. The method of placement and connection of light-emitting elements in their garlands placed in monolithic light-emitting matrices, including a technological cycle from placement in integral performance by known methods on a square or rectangular substrate, the formation of light-emitting elements with discreteness of square or rectangular cell areas of light-emitting elements, garlands with the same the number of series-connected light-emitting elements in closed concentric or rectangular fields, divided x insulating tracks for their subsequent parallel connection until the end product - the light emitter, to increase the uniformity of the radiation of the emitter on the illuminated surface of a concentric or rectangular field, the reliability of the emitter in the event of failure of one or more daisies, its testing for operability in case of failure of one or more daisies, characterized in that in the plane of placement of the light-emitting elements in a closed field, the light-emitting elements are placed by repeating groups of light emitting At first, in direct order, then in the opposite direction, light-emitting elements with virtual numbers of garlands inside the groups are connected in series, for example, on the right side, and between adjacent groups on the left side, with conductors adjacent to each other alternately parallel oriented axes of the location of the light-emitting elements in a closed field in the case of the placement of conductors in the plane of placement of the light-emitting elements, in the case of level connection of light-emitting elements under the plane of placement of light-emitting elements by conductors in the insulating layers, the connection of the light-emitting elements is carried out by connecting metallization through the insulating layers with the corresponding conductors on the insulating layers, which are arranged along two virtual disjoint lines along which, for example, on the left side of the connection with the light-emitting elements inside groups of light-emitting elements, and on the right side between adjacent groups and in the absence of conductors in previous layers. 2. The method according to claim 1, characterized in that for error-free connection of the light-emitting elements with conductors in the insulating layers along the left and right virtual pins, the plane with the conductors of the connection of the light-emitting elements in the same plane placed on it is bent along the axis of location of the light-emitting elements in a closed field to alignment with the insulation width between the left and right conductors and through them draw parallel planes equal to the number of daisies in a closed field of light-emitting elements in which insulating layers with left and right conductors.

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