RU2426200C1 - Method of chaining and checking led matrices - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: proposed method comprises placing strings of with certain number of mini LEDs connected in series in integral field at concentric fields of varying geometry. Said integral field is uniformly divided into sections in concentric fields multiple of certain number of mini LCDs to be connected in string of mini LCDs. All strings made are connected in parallel. Finished integrated LED matrix is connected to weak current. Current is set to ensure visual or instrumental determination of the number and configuration of faulty concentric strings and brightness of sound strings. After determination LED matrix permissible current is corrected and type of string is defined.

EFFECT: uniform illumination, higher reliability.

3 cl, 15 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 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. energy of a light stream improves. (Components and technologies. 2005. No. 7. “Why LEDs do not always work the way their manufacturers want”).

So in the well-known high-power Acriche LEDs, already in integral design, a parallel connection of several “garlands” of mini-LEDs is used (Components and Technologies. 2007. No. 7. “New LED Light Source”), which also have a rectangular or square arrangement.

Currently known series-parallel matrix connection of LEDs (Electronic components. 2009. No. 8. P.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. However, even if in this case the brightness of the LEDs is equalized, when the matrix of LEDs is placed squarely, the finished product will emit a square beam shape and instead of a flat circle like ordinary lamps, a square blurred at the edges will be clearly expressed, i.e. in the circle that describes it, dark spots will be noticeable to the sides adjacent to it, and therefore, in the future, even when various diffusion means are used in luminaires, uneven sections of illumination will still exist.

The placement of LED cells in integrated design form at the design stage in the manufacture of various stencils required in the technological cycle. In this process, crystalline layers are grown on an insulating substrate, then various sputtering and selective etching are performed to obtain the desired properties of the mini-LEDs and their interconnections in all the numerous mini-LED matrices 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 during spraying and etching, they nevertheless arise. As a result, this leads to the failure of the functioning of individual "garlands".

The closest in technical essence and the achieved result is a light-emitting device containing light-emitting elements described in the application RU 2005103616 A (10.10.2005) (prototype).

This device uses a series-parallel connection of light-emitting elements, consisting of two "garlands" containing the same number of light-emitting elements placed in the form of zigzag structures, and the overall shape of the set of light-emitting elements is made in the form of a square.

This device does not solve the problems of the reliability of the emitter in case of failure of one of the "garlands", due to an open circuit, and even the zigzag structure of mini-LEDs placed in a square shape does not contribute to the uniformity of radiation in the light beam in the emitting device.

The objective of the invention is to find methods for placing mini-LEDs in their integrated matrix for uniform radiation, increasing the reliability of the LED matrix in the manufacturing, testing, classification, operation and, accordingly, increasing the percentage of suitable products.

The technical result - uniform radiation, increasing the reliability of the LED matrix in the manufacturing, testing, classification, operation and, accordingly, increasing the percentage of suitable products is achieved by the fact that the "garlands" of LED elements are placed in an integral field in concentric fields that are not repeated in shape from the center containing a certain or multiple of the number of LED elements found in the original garland, and concentric garlands with a certain the LED elements are connected in parallel, and the concentric fields of the LED elements with a greater multiplicity of a certain number are evenly divided into pieces, which, with appropriate alternation, are sequentially connected into “garlands” with the previously determined number of LED elements for their subsequent parallel connection with the previous “garlands”, and, further, the finished formed concentric LED matrix in the integrated design after all technological processes are connected to low current sufficient for visual or using intermediate devices to determine the number and configurations of failed concentric “garlands” of LED elements, as well as the brightness of suitable “garlands” to correct the permissible total current of the emitter, determine the class of the future LED emitter and, accordingly, increase the percentage of output suitable concentric LED matrices.

Figure 1 simplified shows a fragment 1 of the LED matrix 2, a top view.

Figure 2 shows a section along aa fragment 1 of the LED matrix 2.

Figure 3 shows a schematic illustration of a fragment 1 of the LED matrix 2.

Figure 4 shows the construction of circles on a checkered field for the initial moment of construction of one of the options for a concentric LED matrix 2.

Figure 5 shows the initial moment of construction of two concentric fields 16-1 and 16-2 of the concentric LED matrix 2.

Figure 6 shows the first constructed version of the LED concentric matrix 2.

7 shows a variant of the image of this matrix with shaded odd fields 16.

On Fig shows the first constructed version of the LED concentric matrix 2, the image of which shows a possible partition of the odd concentric fields 16 to form a string of lights with a constant number of LEDs 6.

Figure 9 shows the first constructed version of the LED concentric matrix 2, the image of which shows the possible dismemberment of even concentric fields 16 to form a daisy chain with a constant number of LEDs 6.

Figure 10 shows the second constructed version of the LED concentric matrix 2 with an image for clarity, the numbers of the odd fields 16 and the dimming of the even fields 16.

11 shows again the second constructed version of the LED concentric matrix 2 with an image for clarity, the numbers of the even fields 16 and the darkening of the odd fields 16.

On Fig shows a third constructed version of the LED concentric matrix 2 with an image for clarity, the numbers of the odd fields 16 and the darkening of the even fields 16.

On Fig again shows the third constructed version of the LED concentric matrix 2 with the image for clarity, the numbers of the even fields 16 and the darkening of the odd fields 16.

On Fig shows the fourth constructed version of the LED concentric matrix 2 with an image for clarity, the numbers of the odd fields 16 and the darkening of the even fields 16.

On Fig again shows the fourth constructed version of the LED concentric matrix 2 with an image for clarity, the numbers of even fields 16 and darkening of the odd fields 16.

As can be seen from the drawing of one of the possible embodiments (Figs. 1, 2), fragment 1 of the LED matrix 2 (Figs. 6-15), the borders 3 of cell 4 are arbitrary, and stencils and masks are necessary at the stages of formation by metal spraying and selective etching jumpers 5 and LEDs 6 in the grown crystals with light emitting transitions 7 and emitting surfaces 8 of the LEDs 6 on the insulating substrate 9. The insulating substrate 9 is provided with an insulating layer 10 that separates the parallel connection bus 11 from the jumpers 5 of the concentric irlyand LED 6 with the webs 12 and the insulating layer 13 from the bus 11 bus 14 a parallel connection of the ends of concentric strings of LEDs 6 with the webs 15.

Since the conditional fields of cells 4 are rectangular, the rectangular matrix is optimal for using the crystal area. However, the disadvantages of a similar shape of the emitter of the LED emitting matrix were mentioned earlier and the concentric shape of matrix 2 is optimal from the emitter’s point of view, but this drawback can also be eliminated by placing a cut rectangle with an LED matrix combining the wiring of the connection of parallel garlands, possibly even with their conclusions for various use in finished fixtures.

For further study of the placement of the LEDs 6 in the concentric matrix 2 and the visibility of its image, the natural view of the fragment 1 of the matrix 2, shown in figure 1, is not suitable. Therefore, the following figures are shown schematically, as shown in the fragment of figure 3, with the allocation of all concentric fields 16 of the studied concentric matrices 2 by hatching or darkening the odd ones, Figs. 7, 11, 13, 15 (or even, Figs. 8, 12, 14 ), concentric fields 17.

The construction of the concentric matrix 2 is carried out on a cellular field 18 (figure 4), the cell of which is taken as the field of the cell 4 of the LED 6, by forming circles 20 from the center 19 with an increasing radius by the size of the field of the cell 4. Two options for constructing these circles are possible: the first is from the center 19 of the square 21, formed by four cells 4 (Fig.4, 5), and the second, when the center 19 of the formation of circles 20 is in the center of the field 22 of the cell 4 (Fig.14, 15). Accordingly, different “pictures” of concentric fields 16 of the concentric matrix 2 are also formed. Recall the task is to find constructions with a maximum number of concentric fields 16 with the same number of cell fields 4 entered into them.

We show examples of unsuccessful and successful constructions.

From the center 19 of the four cells 4, Fig. 4, in the checkered field 18 we form, for example, 8 circles with the addition of the length of the cell 4 to their radii. In a circle 20-2 with a radius of two lengths of cell 4, forming a concentric field 16-1, we write in the cells of the fields of cells 4 cross-shaped "embryo" 16-1 (figure 5), consisting of 12 cells. In a quarter of the circumference 20-3, and this guarantees the symmetry of the formed concentric field 16-2, it is possible to enter only 3 cells in the second concentric field, and this multiplied by 4 is 12. In the third layer 16-3, Fig.6, 7 , it is possible to enter 6 × 4 = 24 cells, in the fourth 16-4 - 24, in the fifth 16-5 - 36, in the sixth 16-6 - 36, in the seventh 16-7 - 48. We get a sequence of numbers containing the number of cells in relevant fields 16:

12; 12; 24; 24; 36; 36; 48.

In the obtained schematic image of the concentric matrix 2, Fig.6, there is no clarity, therefore (in the manufacture of stencils this is not required) in this description for clarity of the arrangement of the concentric layers 16 in Fig.7, the odd fields 17 are darkened.

So, in the first two concentric layers 16-1 (Fig. 8), 16-2 (Fig. 9), 12 cells are stacked, in the third 16-3-1, 16-3-2 (Fig. 8) and the fourth 16-4-1, 16-4-2 (Fig. 9), two initial number of cells 2 × 12 = 24. Those. in the future, in a concentric matrix 2 in these fields, two garlands of LEDs 16-3-1, 16-3-2 (Fig. 8) and 16-4-1, 16-4-2 (Fig. 9) of 12 LEDs will be stacked 6. In the fifth 16-5 and sixth 16-6 layer, 3 garlands of 16-5-1, 16-5-2, 16-5-3 will be stacked (Fig. 8), 16-6-1, 16-6- 2, 16-6-3 (Fig. 9), and in the seventh 16-7 - already 4-16-7-1, 16-7-2, 16-7-3, 16-7-4 (Fig. 8).

The only problem is that for uniform radiation, the concentric field 16 will have to be divided into a large number of alternating pieces 16-ij, which then need to be combined into parallel garlands of 16-ij with 12 LEDs 6, which with a large number of them in the concentric layer 16-i already quite difficult and reduces the reliability of the future LED emitter. Therefore, the construction of the concentric matrix 2 in figure 4 will be considered unsuccessful.

Cutting from the “embryo” 16-1 in FIG. 5 a “window” 21 (FIG. 4) from four central cells, thereby reducing the constant number of the “embryo” 16-1 to 8 cells and limiting it to 11 concentric fields, making a similar construction ( 10, 11) of concentric fields 16-i (odd even fields in this description are shown separately in FIG. 10, 11 for clarity), we obtain a sequence of numbers in them containing the number of cells in each as:

8; 16; 24; 24; 32; 40; 48; 56; 56; 64; 64,

which is also unacceptable.

However, in the same embodiment, with a “window” 21 cut out (Fig. 4) of four cells 4 and, inscribing in a circle 20-4 with a radius of four cell lengths 4 (Figs. 12, 13), we obtain the “embryo” field 16- 1, equal to 36 cells 4. Restricting ourselves to 11 concentric fields, further construction gives a series of numbers corresponding to the number of cells 4 in the formed concentric fields 16-i, as:

36; 36; 36; 36; 36; 72; 72; 72; 108; 108; 108.

At least, it is already possible to immediately arrange five parallel strings (16-1, 16-2, 16-3, 16-4, 16-5) of 36 LEDs 6. You can also, removing the first concentric field 16-1 and combining in pairs of the following 4 concentric fields 16-2, 16-3 and 16-4, 16-5, get 4 garlands of 72 LEDs 6. Or, if you combine the first three concentric fields 16-1, 16-2, 16-3 and the fourth field 16-4 to the sixth 16-6, and the fifth 16-5 to the seventh 16-7, then you can get 6 garlands of 108 LEDs 6.

If technological conditions allow the parallel connection of garlands separated by dissected alternating segments 16-i-j of the 16-i concentric field, then the number of garlands in the first five concentric fields 16, 16- (1-5) of 36 LEDs 6 with 1 garland. In the next two, 16- (6-7), 72 LEDs 6 each have 2 garlands, and in the next three, 16- (8-10), out of 108 three, the total will be 18 garlands of 36 LEDs 6.

Another option for constructing a concentric matrix is shown in Figs. 14, 15. The matrix is constructed from the center 19 of one cell 4, from the “embryo” field 16-1, inscribed in a circle 20-3 with a radius of three lengths of cell 4 minus the central field 22 in the form of a cross of 5 cells 4, containing as a result a constant number equal to 16. Restricting ourselves to 11 concentric fields, with the further construction of the concentric matrix we get a series of numbers with the number of cells 4 in concentric fields 16-i as:

16; 16; 32; 32; 64; 64; 64; 64; 64; 64; 64; 128.

If we remove the first two layers 16-1, 16-2 and combine the third, 16-3, and the fourth, 16-4, then without any splitting of the layers 16 we get 8 strings of 64 LEDs 6.

Recall that the number of LEDs 6 in the garland at a given current determines the operating voltage on it, and the number of garlands determines the emitted power and brightness of the LED emitter.

Let the current of the LED 6-30 mA and the voltage drop across it be 3.2 V. Then the voltage on one 16-ij daisy chain (Figs. 14, 15) with 64 LEDs 6 will be 204.8 V, and the allocated power - 6.144 W , which is already quite a lot, but will correspond in emission to approximately the equivalent of a 60-watt incandescent bulb. Eight garlands will already emit about 50 W, which already creates certain problems with heat removal from the LED emitter, solved by known methods, although the generated power can be reduced by reducing the size of the LED elements or by increasing the brightness of the radiation and, accordingly, reducing the current flowing through them.

Therefore, it is still preferable variant of Fig. 12, 13, in which the garlands consist of 36 LEDs 6, then the voltage on the 16-ij garland will be 115.2 V, and the power consumption is 3.456 W, which is equivalent to approximately the brightness of a 30-watt incandescent bulb . Five garlands will consume 17.28 watts and correspond to a 150-watt incandescent light bulb.

With the improvement of LED technology, most likely, there will be ways to increase the emitting power of LEDs 6, which will lead to a decrease in the current flowing through them, and, accordingly, to a reduction in power consumption, and to the possibility of increasing the number of daisies and increasing the reliability of light-emitting devices based on concentric LED matrices 2.

The given examples of constructing concentric LED matrices have been constructed empirically, although in the future there may be some mathematical patterns and, probably, other optimal options for constructing concentric fields of the 16-i concentric LED matrix 2, but in this case the shown is important the principle of their construction.

As you know, LEDs are current devices and if they are assembled in parallel connected garlands with a current already set for all, the difference in their current characteristics and even more so the failure of even one of them sometimes causes a significant redistribution of currents in the remaining suitable garlands, which can cause a limiting current in one or more garlands. As noted earlier, with integrated technology, due to the small size of the concentric matrix, the characteristics of the LEDs 6 are approximately the same, therefore, the disadvantage in the first case due to the voltage difference in the garlands is automatically eliminated. The hardest thing is the failure of some garlands. In the case when there are a lot of garlands connected in parallel, the failure of one or several garlands will be little noticeable. However, if the garlands are not more than a dozen, the failure of one or several garlands with a constant supply current, the current in suitable garlands will increase significantly, but their brightness will also increase. Therefore, in order not to cause the maximum current in the garlands during the control check of the matrix, it should be powered with such a current that even with one suitable garland the maximum current does not appear in it. For example, for the variant of FIG. 12, 13 for five daisies, the rated current is 150 mA. For one more suitable garland, such a current, even at initial start-up, can lead to a hopeless failure of the LED matrix. By sequentially increasing the current, in this case from 30 mA, it is easy to visually or with the help of intermediate devices determine the number of suitable strings and the permissible current for the entire matrix, as well as, accordingly, determine the class of the future LED emitter. For example, if there are 3 valid garlands left, now the rated current of the matrix should be equal to 90 mA. With this technology, the industrial output of LED arrays will be significant. Due to the fact that all the garlands are concentric in shape, even one suitable one will produce circular radiation, for which it will be easier to create a scattering medium in the lamp, smoothing out the absence of glow from the failed garlands.

Bibliography

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Claims (3)

1. A method of forming and testing LED matrices, including the technological cycle from placement in an integrated version by known methods on a substrate with discrete cell areas of LED elements, followed by a series connection of LED elements into garlands and parallel connection of garlands of LED elements to the output of the final product - light emitter and its verification operability, characterized in that the garlands of LED elements are placed on the integral field of the substrate in the last The concentric fields that are not repeated in shape from the center and contain a certain or multiple of the number of LED elements found in the initial garland, with concentric garlands with a certain number of LED elements being connected in parallel, and the concentric fields of LED elements with a greater multiplicity of a certain number are uniformly divided into pieces that with the appropriate alternation, they are sequentially connected in garlands with the previously determined number of LED elements for their subsequent parallel connection with the previous garlands, and then the finished formed concentric LED matrix in integral design after all technological processes are carried out, is connected to a low current sufficient to determine the number and configuration of failed concentric garlands of LED elements visually or with intermediate devices, as well as suitable brightness garlands and according to the received data correct the permissible value of the total current of the emitter, determine the classes will light emitters and the percentage of yield of concentric LED matrices. 2. The method according to claim 1, characterized in that the optimal certain number of cells in a concentric field when constructing all concentric fields is found empirically by counting the number of cells inscribed in the first few circles from the center with radii with increasing multiples of the size of the cell length with an integrated LED element less or not deduction and, accordingly, removing or not deleting the placement of a certain number of cells around the center for constructing concentric fields. 3. The method according to claim 1, characterized in that the largest number of subsequent concentric fields with a certain or multiple of the number of cells of LED elements and their construction is carried out by selecting appropriate symmetric non-repeating configurations of concentric fields formed between the difference of the radii of increasing magnitude by the cell length light emitting element equal to the size of the lengths of one or more cells.

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