JP2018026540A - Display module including array of led chip group - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display module in which color reproducibility is improved significantly.SOLUTION: A display module includes a substrate 110, multiple electrode patterns including first individual electrode pads 131 formed on the substrate side by side in the lateral direction, second individual electrode pads 132, third individual electrode pads 133, and common electrode pads formed on these electrode pads side by side in the longitudinal direction, and an LED chip group including a first LED chip 151 where a one side (1-1)th electrode 151a being bonded to the first individual electrode pad and the other side (1-2)th electrode being bonded to the common electrode pad are formed, a second LED chip 153 being bonded to the second individual electrode pad, and a third LED chip 155 being bonded to the third individual electrode pad. The first LED chip, second LED chip and third LED chip are connected individually with the input power supply, and can be controlled individually.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a display module that includes an array of LED chip groups arranged in a matrix, and each LED chip group emits light of a different wavelength, and includes a first LED chip, a second LED chip, and a third LED chip.

  Instead of a display device in which LEDs are used as a backlight light source, a full-color LED display device has been proposed in which LEDs emitting light of different wavelengths are grouped to form pixels. At this time, each pixel is configured by a red LED, a green LED, and a blue LED, or is configured by a red LED, a green LED, a blue LED, and a white LED. In such an LED display device, each of the red LED, the green LED, and the blue LED is manufactured in a package unit and mounted on a substrate. In this case, the distance between the LEDs constituting each pixel is increased. Difficult to get high quality resolution. And when it comprises a pixel with each LED of a package unit, application to the micro LED display apparatus which attracted attention recently was difficult. Conventionally, an LED pixel unit has been proposed in which a red LED, a green LED, and a blue LED constituting one pixel are mounted in one package. In this case, the distance between the LEDs in one pixel, that is, the distance between the sub-pixels is reduced, but it is difficult to reduce the distance between the pixels. Further, there is a possibility that light interference may occur between the red LED, the green LED, and the blue LED.

  Therefore, the inventors of the present invention arranged the LED display module by arranging each group including a red LED chip, a green LED chip, and a blue LED chip in a matrix on the substrate in order to reduce the spacing between pixels. I tried to embody. However, it has been difficult to mount each LED chip having a fine size on a substrate so as to have a constant height and a constant interval. The difference in height and spacing between the LED chips mounted on the substrate reduces the color reproducibility. In addition, wire bonding is necessary for electrical connection between the electrode pad on the substrate and the LED chip. By such wire bonding, at least several tens of hours to several hundreds are required to produce one product. Time working hours are needed.

  In particular, during the process of mounting several tens to several hundreds of LED chips on a substrate, the LED chips are not accurately positioned at the desired position, and the target light emission pattern cannot be realized at the time of design, resulting in severe color deviation. did.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide light of different wavelengths included in each of a plurality of LED chip groups arranged in a matrix on a substrate. An object of the present invention is to provide a display module in which the mounting height of each LED chip is uniform and the color reproducibility is greatly improved.

  In order to achieve the above object, a display module according to an aspect of the present invention includes a substrate, a first individual electrode pad, a second individual electrode pad, and a third individual electrode formed side by side on the substrate. A plurality of electrode patterns including an electrode pad, a first individual electrode pad, a second individual electrode pad, and a common electrode pad formed in a vertical direction on the third individual electrode pad; A first LED chip on which a first 1-1 electrode on one side bonded to an electrode pad and a first-2 electrode on the other side bonded to the common electrode pad are formed, and one bonded to the second individual electrode pad. A second LED chip on which a second 2-1 electrode on the side and a second 2-2 electrode on the other side bonded to the common electrode pad are formed, and a bond on the third individual electrode pad. An LED chip group including a third LED chip on which a third electrode on one side to be bonded and a third electrode on the other side bonded to the common electrode pad are formed. The first LED chip, the second LED chip, and the third LED chip are individually connected to an input power source through the first individual electrode pad, the second individual electrode pad, and the third individual electrode pad, Each is connected to the common electrode pad and can be independently controlled.

In the LED chip group, the first LED chip, the second LED chip, and the third LED chip emit light having different wavelengths, respectively, and may be arranged in a matrix at the same height on the substrate.
The LED chip groups are plural, and the horizontal intervals and vertical intervals of the plurality of LED chip groups are the same.
The horizontal and vertical intervals of the electrode patterns formed on the substrate are the same so that the first LED chip, the second LED chip, and the third LED chip are arrayed at a predetermined interval. Can be formed.

The first individual electrode pad, the second individual electrode pad, and the third individual electrode pad are constant so that the first LED chip, the second LED chip, and the third LED chip are arrayed at a predetermined interval. Can be formed side by side.
The plurality of electrode patterns may be formed to have a certain pattern and a certain height.
The common electrode pad may include a first branch, a second branch, and a third branch to which the first-2 electrode, the second-2 electrode, and the third-2 electrode are respectively connected.

Each of the first branch, the second branch, and the third branch may be a region where a bonding bump on the other side of the LED chip is bonded.
The first individual electrode pad, the second individual electrode pad, and the third individual electrode pad may be a region where a bonding bump on one side of the LED chip is bonded.
The first individual electrode pad, the second individual electrode pad, and the third individual electrode pad are one end that coincides with the second edge line, and the other adjacent to the common electrode pad on the opposite side. It may include side edges and laterally parallel sides.
The substrate may be a rigid type having a flat surface or a flexible type.

  According to the present invention, in a process of producing a display module by applying a large number of chips, a plurality of light emitting diode chips are positioned at accurate positions on a substrate, and electrical connection of each light emitting diode chip is performed in a desired pattern. By omitting the process of electrically connecting each LED chip by wire bonding, cost savings and productivity improvement can be achieved through shortening the process time, and defect problems and product performance can be improved. Problems such as degradation can be solved.

1 is a plan view showing a substrate of a display module according to an embodiment of the present invention and an array of electrode patterns formed in a matrix on the substrate. FIG. 2 is a plan view showing a display module including LED chip groups arranged in a matrix in each electrode pattern shown in FIG. 1. It is sectional drawing for demonstrating a LED chip group. FIG. 6 is a plan view showing a display module according to another embodiment of the present invention. 5 is a flowchart illustrating a method for manufacturing a display module according to an exemplary embodiment of the present invention. FIG. 3 is a schematic view illustrating a method of mounting each LED chip on a substrate by a transfer printing method for manufacturing a display module according to an embodiment of the present invention.

  Hereinafter, specific examples of embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the present specification, the same or similar components are given the same or similar reference numerals even in different embodiments, and the description thereof refers to the first description.

  FIG. 1 is a plan view showing a substrate of a display module according to an embodiment of the present invention and an array of electrode patterns formed in a matrix on the substrate. FIG. 2 is a plan view showing a display module including each LED chip group arranged in a matrix in each electrode pattern shown in FIG. FIG. 3 is a cross-sectional view for explaining the LED chip group.

  1 to 3, a display module 100 according to an exemplary embodiment of the present invention includes a rectangular substrate 110 and a plurality of substrates 110 arranged in a matrix so as to have a certain height on the substrate 110. Electrode patterns 130 and a plurality of LED chip groups 150 arranged in a matrix on the substrate 110 so as to correspond to the electrode patterns 130.

  The substrate 110 is an object on which the LED patterns 130 are formed and the LED chips (151, 153, 155) are mounted thereon. As the substrate 110, a large number of LED chips (151, 153, 155) are fixed. A flat thing is used so that it may be mounted in height. Accordingly, when the substrate 110 has a flat surface, the substrate 110 may be a rigid type or a flexible type. Specifically, the substrate 110 is a rigid plastic substrate, a ceramic substrate, a glass substrate, or a flexible substrate such as an FPCB.

  As described above, the plurality of electrode patterns 130 are formed in a matrix on the substrate 110 and have the same height as a whole. For example, a conductive metal film formed with a certain thickness on a flat surface of the substrate 110 may be partially removed by etching or the like, or a conductive material having a certain pattern may be used using a mask on the flat surface of the substrate 110. By forming the conductive metal film at a certain height, a plurality of electrode patterns 130 having a certain height are formed.

  The plurality of electrode patterns 130 are formed in a matrix arrangement including a horizontal direction and a vertical direction. In the present embodiment, the horizontal direction is defined as a direction parallel to the line Lx shown in FIGS. The vertical direction is defined as a direction parallel to the line Ly shown in FIGS.

  Each of the electrode patterns 130 includes a common electrode pad 139 aligned along a first edge line EL ′ parallel to the vertical direction of the matrix arrangement, and a second edge line EL parallel to the first edge line EL ′. And a first individual electrode pad 131, a second individual electrode pad 132, and a third individual electrode pad 133 that are positioned between the first edge line EL ′ and the second edge line EL.

  At this time, the first individual electrode pad 131, the second individual electrode pad 132, and the third individual electrode pad 133 are individually connected to an input power source (not shown) in the completed electric circuit, and will be described in detail below. Allows independent control of each LED chip described.

  The common electrode pad 139 has two grooves that are recessed inward in a substantially rectangular shape with respect to the first edge line EL ′, and three branches whose shape is limited by the two grooves. That is, the first branch 136, the second branch 137, and the third branch 138 are included. Each of the first branch 136, the second branch 137, and the third branch 138 defines a region where a bonding bump on one side of each LED chip is bonded, and each LED chip is flip-chip bonded. At this time, it contributes to preventing short-circuit failure caused by undesired twisting or slipping of each bonding bump.

  The first individual electrode pads 131, the first LED pads 151, the second LED chips 153, and the third LED chips 155 are arranged at regular intervals so as to be described in detail below. The two individual electrode pads 132 and the third individual electrode pad 133 are formed side by side with a predetermined interval. Each of the first individual electrode pad 131, the second individual electrode pad 132, and the third individual electrode pad 133 defines a region where the bonding bump on the other side of each LED chip is bonded.

  The first individual electrode pad 131, the second individual electrode pad 132, and the third individual electrode pad 133 are on one side end portions (131b, 132b, 133b) that coincide with the second edge line EL and on the opposite side. It includes other side end portions (131c, 132c, 133c) which are close to and adjacent to the common electrode pad 139 and side portions (131a, 132a, 133a) parallel to the lateral direction. In addition, the first individual electrode pad 131, the second individual electrode pad 132, and the third individual electrode pad 133 have a narrow width portion located on one side end portion (131b, 132b, 133b) side and an other end portion ( 131c, 132c, 133b) and a wide portion having a width larger than the narrow portion. The position where the bump is formed is determined on the wide portion.

  The other end portions (131c, 132c, 133c) of the individual electrode pads (131, 132, 133) are the end portions of the branches (136, 137, 138) of the common electrode pad 139 that coincide with the first edge line EL ′. Parallel to (136 ′, 137 ′, 138 ′) and located close adjacent.

  As shown in FIGS. 1 and 2, each of the plurality of LED chip groups 150 is arranged in a line along the vertical direction, and emits light of different wavelengths, and the first LED chip 151, the second LED chip 153, and 3 LED chips 155 are included. In the present embodiment, the first LED chip 151 is a red LED chip that emits light in a substantially red wavelength band when power is applied, the second LED chip 153 is a green LED chip that emits light in a green wavelength band, and the third LED chip. Reference numeral 155 denotes a blue LED chip that emits light in a blue wavelength band.

  The first LED chip 151 is bonded to the first branch 151 of the common electrode pad 139 by the 1-1 electrode 151a and the 1-2 bump 171b, which are bonded to the first individual electrode pad 131 by the 1-1 bump 171a. The first and second electrodes 151b are provided on the surface facing the substrate 110.

  The second LED chip 153 is bonded to the second branch 137 of the common electrode pad 139 with the 2-1 electrode 153a bonded to the second individual electrode pad 132 by the 2-1 bump 173a and the 2-2 bump 173b. The second electrode 153b is provided on the surface facing the substrate 110.

  The third LED chip 155 is bonded to the third branch 138 of the common electrode pad 139 by the third electrode 155a bonded to the third individual electrode pad 133 by the third bump 175a and the third bump 175b. The third electrode 155b is provided on the surface facing the substrate 110.

  All LED chips (151, 153, 155) that are flip-chip bonded and arranged in a matrix on the substrate 110 need to have substantially the same height in order to obtain the intended color reproducibility. For this reason, all LED chips including the first LED chip 151, the second LED chip 153, and the third LED chip 155 have the same height, one side of the first LED chip 151, one side of the second LED chip 153. The height of the 1-1 electrode 151a, the 2-1 electrode 153a, and the 3-1 electrode 155a placed on one imaginary straight line in a state formed on one side and one surface of the third LED chip 155 The first LED chip 151 is placed on the same imaginary straight line in a state of being formed on the other side of the first LED chip 151, the other side of the second LED chip 153, and the other side of the third LED chip 155. The heights of the first-second electrode 151b, the second-second electrode 153b, and the third-second electrode 155b are substantially the same.

  In addition, the 1-1 bump 171a, the 2-1 bump 173a, and the 3-1 bump 175a have a fixed first height in a finally compressed state, and the 1-2 bump 171b, The second-2 bump 173b and the third-2 bump 175b have a constant second height in a finally compressed state, and are the first LED chip 151, the second LED chip 153, and the third LED chip 155. The first height and the second height are determined to be different from each other so as to compensate for the height difference due to each step.

  The step of each LED chip (151, 153, 155) has an epi structure including a laminated structure of a translucent growth substrate (particularly a sapphire substrate), a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer. The second conductive type semiconductor layer exposed on the lower side and a part of the active layer in contact with the second conductive type semiconductor layer are removed by etching to expose the first conductive type semiconductor layer on the lower side.

  Further, the step difference due to etching can be reduced by making the heights of the two electrodes provided in the LED chip different from each other, but there is also a fine step difference in this case. In this case, the heights of the 1-1 bump 171a, the 2-1 bump 173a, and the 3-1 bump 175a are not compressed and the heights thereof are the 1-2 bump 171b and the 2-2 bump 173b. , And the same height as the 3-2 bump 175b. However, in a state where each of the bumps described above is finally compressed, the first 1-1 bump 171a and the second bump 171a are compensated so as to compensate for the step of the LED chip that is taken into consideration up to the height of each electrode provided in each LED chip. -1 bump 173a and 3-1 bump 175a are finally compressed in a first height, and 1-2 bump 171b, 2-2 bump 173b, and final 3-2 bump 175b are final. The height of the compressed state can be changed.

  In addition, each of the 1-1 bump 171a, the 2-1 bump 173a, and the 3-1 bump 175a is compressed to the first height, and the first individual electrode pad 131 and the second individual electrode pad 132 are compressed. And a bonding area of 50% to 80% with respect to the upper surface area of the wide portion of the third individual electrode pad 133. The first 1-2 bump 171b, the second-2 bump 173b, and the third-2 bump 175b are finally compressed, and the first branch 136, the second branch 137, and the third branch 138 are respectively compressed. It has a bonding area of 50% to 80% with respect to the upper surface area.

  As described above, each bump (171a, 173a, 175a, 171b, 173b, 175b) has a bonding area of 50% to 80% with respect to the upper surface area of each branch of each individual electrode pad or common electrode pad. Therefore, even if the bonding is performed outside the region corresponding to the bonding area, contact with other adjacent bumps is suppressed, and as a result, the risk of occurrence of a short circuit can be prevented. In other words, even if a region to which the bumps (171a, 173a, 175a, 171b, 173b, 175b) are bonded is determined in advance, the bump is biased toward the other bump adjacent to it due to a minute twist or slip in an actual process. There is a possibility, but if the bonding area is limited to within 80% as described above, even if the bumps (171a, 173a, 175a, 171b, 173b, 175b) slip or twist in the actual process, they are adjacent to each other Since it does not come into contact with the bump, the occurrence of a short circuit is blocked. On the other hand, when the bonding area is less than 50%, a reliable bonding is not formed. Therefore, the area where the bump is finally bonded to the individual electrode pad or branch is preferably at least 50% or more.

  Each of the first branch 136, the second branch 137, and the third branch 138 is a part of the common electrode pad, and the first-2 bump 171b, the second-2 bump 173b, and the third-2 bump 175b are included. The bonding area is defined, and a short-circuit failure that may occur due to twisting or slipping of the 1-2 bump 171b, the 2-2 bump 173b, and the 3-2 bump 175b in the flip chip bonding process is fundamentally blocked. . In other words, if the first, second, and third branches (136, 137, 138) separated from each other by the grooves on one side of the common electrode pad 139 are not disposed, the 1-2 bump is formed in the flip chip bonding process. 171b, 2-2 bump 173b, or 3-2 bump 175b may slide or twist on the common electrode pad, resulting in a short circuit failure, but the first, second, and third branches (136, 137, 138). ), The area where the 1-2 bump 171b, the 2-2 bump 173b, and the 3-2 bump 175b slide or twist on the common electrode pad 139 is limited, and the above-described defects can be prevented. Can do.

  As described above, a large number of LED chips (151, 153, 155) flip-chip bonded on the substrate 110 are grouped into a number of LED chip groups 150 having a matrix arrangement. Is composed of a first LED chip 151, a second LED chip 153, and a third LED chip 155 that are arranged at regular intervals along the vertical direction. The first LED chip 151, the second LED chip 153, and the third LED chip 155 belonging to each LED chip group 150 are the first and second electrodes 151a, 153a, and 3-1a. The first and second electrodes 151b, 153b and 153b are electrically connected to the common electrode pad 139. Are individually controlled by being connected to each other.

  On the other hand, the horizontal intervals and the vertical intervals of the LED chip groups 150 arranged in a matrix on the substrate 110 are the same. Furthermore, the horizontal intervals of the LED chip groups 150 and the vertical intervals of the LED chips (151, 153, 155) are the same. Therefore, the horizontal and vertical intervals of the electrode patterns 130 formed in a matrix on the substrate 110 so as to correspond to the LED chip groups 150 are the same. Furthermore, it is preferable that the horizontal interval between the electrode patterns 130 and the vertical interval between the electrode patterns 130 are the same.

  Further, the distance between the first LED chip 151 and the second LED chip 153 and the distance between the second LED chip 153 and the third LED chip 155 are the same, and preferably about 0.3 μm to about 1.5 μm. . For example, an FHD class display module is manufactured with an interval between chips of 0.75 μm, and an UHD class display module is manufactured with an interval between chips of 0.375 μm.

  Hereinafter, with reference to FIG. 4, a display module further including an additional configuration different from the above-described embodiment according to another embodiment of the present invention will be described.

  FIG. 4 is a plan view showing a display module according to another embodiment of the present invention. The display module 100 ′ according to the present embodiment includes a barrier 190 that is formed on the substrate 110 and prevents light interference between adjacent LED chips (151, 153, 155). In the present embodiment, the barrier 190 is a first light formed between the first LED chip 151 and the second LED chip 153 adjacent in each LED chip group 150 and between the second LED chip 153 and the third LED chip 155. It includes a reflection wall 191 and a second light reflection wall 193 formed between the LED chip groups 150 adjacent in the vertical direction and between the LED chip groups 150 adjacent in the horizontal direction.

  The first light reflecting wall 191 and the second light reflecting wall 193 interfere with output light between adjacent LED chips in each adjacent LED chip group 150 and between adjacent LED chips in two adjacent LED chip groups 150. Thus, the quality of the output light is prevented from deteriorating. Instead of the barrier 190 including the light reflecting wall, a barrier that absorbs light between the LED chips (151, 153, 155) or between the LED chip groups 150 and prevents light interference may be used.

  Hereinafter, a display module manufacturing method according to the present invention will be described with reference to FIGS. 5 and 6 together with FIGS.

  FIG. 5 is a flowchart illustrating a method for manufacturing a display module according to an embodiment of the present invention. FIG. 6 is a schematic view illustrating a method of mounting each LED chip on a substrate by a transfer printing method for manufacturing a display module according to an embodiment of the present invention.

  The method for manufacturing a display module according to the present invention includes a method of arranging each electrode pattern 130 including the first individual electrode pad 131, the second individual electrode pad 132, the third individual electrode pad 133, and the common electrode pad 139 shown in FIG. As shown in FIG. 2, the first 1-1 bump 171a, the 2-1 bump 173a, and the 3-1 bump 175a are first formed as shown in FIG. The first-2 bump 171b, the second-2 bump 173b, and the third-2 bump 175b are placed on the individual electrode pad 131, the second individual electrode pad 132, and the third individual electrode pad 133. A bump loading stage (S02) for placing on the first branch 136, the second branch 137, and the third branch 138, as shown in FIG. A plurality of LED chips including first, second, and third LED chips (151, 153, 155) having different light wavelength characteristics are mounted on the substrate 110 at a constant height, and a plurality of LEDs are mounted. Arranging the chip groups 150 in a matrix on the substrate 110 (S03).

  In particular, the step of arranging the LED chip groups 150 in a matrix on the substrate 110 (S03) is arranged in a matrix on the support B using a roll-to-roll transfer printing technique. The plurality of LED chips 151, 153, and 155 may be transferred and mounted on the substrate 110 according to the original arrangement.

  As will be described in detail below, the roll-to-roll transfer printing technology for each LED chip (151, 153, 155) includes an adhesive carrier and an adhesive carrier at the time of picking up each LED chip (151, 153, 155). A pick-up roll 40 that pressurizes the LED chip, and a chip placing roll 50 that pressurizes each LED chip (151, 153, 155) when the LED chips (151, 153, 155) are mounted on the substrate 110 are used. The pickup roll 40 and the chip placing roll 50 operate in cooperation with each other at the chip pickup position and the chip mounting position with respect to the adhesive carrier, so that each LED chip (151, 153, 155) is returned to the original arrangement. The substrate B is transferred from the support B and mounted. The adhesive carrier is an element having an adhesive force so that a large number of LED chips (151, 153, 155) can be adhered and moved, and the pickup roll 40 has a large number of LED chips (151, 151, 151) positioned on the support B. 153, 155) is an element that presses the adhesive carrier against each LED chip so that the adhesive carrier is bonded to the adhesive carrier, and the chip placing roll 50 has a number of LED chips according to the arrangement bonded to the adhesive carrier. (151, 153, 155) is an element that pressurizes the substrate 110. In addition, before picking up each LED chip using the pick-up roll 40, the adhesive force of the adhesive carrier is partially weakened, or each LED chip (151, 153, 155) is used as a substrate using the chip placing roll 50. A means for weakening the adhesive strength of the adhesive carrier as a whole just before mounting on 110 is further used.

  As briefly described above, the step of arranging the LED chip groups 150 in a matrix on the substrate 110 (S03) is performed on the adhesive electrode 10a partially having an adhesive strength weakening region by applying the first-first electrode 151a. The first LED chip 151 having the first and second electrodes 151b, the second LED chip 153 having the second and second electrodes 153a and 153b, and the third and third electrodes 155a and 3-2. A step of arranging and bonding the LED chips each including the third LED chip 155 having 155b in a matrix (S1 and S3), the 1-1 electrode 151a, the 2-1 electrode 153a, and the 3-1 Each of the electrodes 155a faces the 1-1 bump 171a, the 2-1 bump 173a, and the 3-1 bump 175a, and the 1-2 electrode 15 b, the adhesive carrier is moved so that the 2-2 electrode 153b and the 3-2 electrode 155b face the 1-2 bump 171b, the 2-2 bump 173b, and the 3-2 bump 175b, respectively. The adhesive carrier moving step (S4), and the 1-1 bump 171a, the 2-1 bump 173a, and the 3-1 bump 175a are compressed to the first height, and the 1-2 bump A chip that pressurizes the first LED chip 151, the second LED chip 153, and the third LED chip 155 with a constant pressure such that the 171b, the 2-2 bump 173b, and the 3-2 bump 175b are compressed to the second height. And a stage-down stage (S7).

  In the step (S1 and S3) of arranging and bonding the LED chips in a matrix, the adhesive carrier 10 is subjected to primary exposure to produce an adhesive carrier 10 ′ in which an adhesive strength weakened region and an adhesive strength non-weakened region are formed. (S1) and a chip pickup stage in which the non-weakened area is pressurized to the LED chips (151, 153, 155) by the rotating pickup roll 40, and the LED chips (151, 153, 155) are bonded to the adhesive carrier 10 ′. (S3).

  First, before the LED chips (151, 153, 155) are arranged in a matrix and attached to the adhesive carrier, the LED chips (151, 153, 155) are arranged and arranged on the support B in a matrix. Placed. Here, the matrix arrangement of each LED chip is a matrix arrangement when each LED chip (151, 153, 155) is attached to the adhesive carrier 10 ′ having the adhesion weakening region in each subsequent process, and each LED chip. Compared with the matrix arrangement when (151, 153, 155) is mounted on the substrate 110, the horizontal and vertical intervals are all the same. Before the LED chips (151, 153, 155) are arranged in a matrix and attached to the adhesive carrier, the adhesive carrier 10 that has not been subjected to the adhesive weakening treatment on the upper side of the LED chips (151, 153, 155). Is disposed, and a photomask 20 and an exposure machine 30 for primary exposure of the adhesive carrier 10 are disposed thereon.

  In the entire area of the adhesive carrier 10, it is necessary to weaken the adhesive force of the area that does not correspond to the LED chips (151, 153, 155). For this reason, in the above-described primary exposure stage (S1), the exposure machine 30 outputs ultraviolet light, and the ultraviolet light is irradiated only to the region not corresponding to the LED chip (151, 153, 155) in the entire region of the adhesive carrier 10 through the through hole of the photomask 20. The ultraviolet light acts on the adhesive carrier 10 at a constant temperature of 200 ° C. or less, and weakens the adhesive force in a partial region of the adhesive carrier 10. As a result, an adhesive carrier 10 ′ in which adhesive strength weakening regions are intermittently formed is prepared.

  In the chip pick-up step (S3), the LED chips (151, 153, 155) are attached to the adhesive strength non-weakening region of the adhesive carrier 10 having the adhesive strength weakening region and the adhesive strength non-weakening region. The pickup roll 40 disposed on the upper side of the adhesive carrier 10 ′ having the adhesive strength weakening region presses the adhesive carrier 10 ′ to the LED chips (151, 153, 155). At this time, each of the adhesive carrier 10 ′ and the support B is maintained in a fixed state, and the entire area of the adhesive carrier 10 ′ is sequentially pressed onto each LED chip (151, 153, 153) while the pickup roll 40 rotates. Such movement of the pickup roll 40 can prevent the LED chips (151, 153, 155) from adhering to the adhesive carrier 10 'while slipping out of the set position.

  In addition, a secondary exposure step is performed in which the adhesive carrier 10 'having a part of the weakened adhesive force is subjected to secondary exposure immediately before the chip placing down step (S7) to produce an adhesive carrier 10 "having a weakened overall adhesive force. Preferably, (S5) is performed, and the chip-plating step (S7) is performed in the LED chip (151, 151) with the chip-placement roll 50 rotating on the adhesive carrier 10 ″ whose adhesion is weakened as a whole. 153, 155) at a constant pressure. Next, a separation step (S9) is performed in which the adhesive carrier 10 ″ whose adhesive strength is weakened as a whole is peeled off from the LED chips (151, 153, 155).

  The pressurization by the rotation of the chip placing roll 50 rotates the chip placing roll 50 so that the LED chips (151, 153, 155) adhered to the adhesive carrier 10 ″ are sequentially attached to the substrate 110. Each of the bumps described above is heated to a predetermined temperature or higher, and the rotating chip placing roll 50 ensures that the LED chips (151, 153, 155) have a predetermined height and interval at a predetermined position on the substrate 110. Implemented.

  According to the above-described method, a large number of LED chips (151, 153, 155) can be mounted on the substrate 110 in a short time, and light having different wavelengths is emitted in such a mounted state. The first, second, and third LED chips (151, 153, 155) can be grouped in units of LED chip groups corresponding to the pixels, and these groups are arranged in a certain matrix to form a display module. can do. Since the LED chips arranged in a predetermined matrix form are bonded together by an adhesive carrier and then moved and mounted on the substrate 110 as they are, each LED chip (151, 153, 155) is mounted. The alignment and spacing between them can be precisely controlled.

  As mentioned above, although embodiment of this invention was described in detail, referring drawings, this invention is not limited to the structure and operation | movement system of embodiment mentioned above. The embodiments described above can be configured such that various modifications can be made by selectively combining all or a part of the embodiments.

10, 10 ′, 10 ″ Adhesive carrier 20 Photomask 30 Exposure machine 40 Pickup roll 50 Chip placing roll 100, 100 ′ Display module 110 Substrate 130 Electrode pattern 131 First individual electrode pad 131a Side part 131b, 131c End part 132 First 2 Individual electrode pads 132a Side portions 132b, 132c End portion 133 Third individual electrode pads 133a Side portions 133b, 133c End portions 136 First branch 136 'End portion 137 Second branch 137' End portion 138 Third branch 138 'End portion 139 Common electrode pad 150 LED chip group 151 First LED chip 151a 1-1 electrode 151b 1-2 electrode 153 2nd LED chip 153a 2-1 electrode 153b 2-2 electrode 155 3rd LED chip 55a 3-1 electrode 155b 3-2 electrode 190 Wheelchair 191 the first light reflecting wall 193 second light reflecting walls 171a, 171b, 173a, 173b, 175a, 175b the bumps B support

Claims (11)

A substrate,
A first individual electrode pad, a second individual electrode pad, and a third individual electrode pad formed side by side on the substrate, the first individual electrode pad, the second individual electrode pad, and the third A plurality of electrode patterns including a common electrode pad formed side by side on the individual electrode pads; and
A first LED chip having a first electrode 1-1 on one side bonded to the first individual electrode pad and a first electrode 1-2 on the other side bonded to the common electrode pad; and the second individual electrode pad. The second LED chip on which the second electrode 2-1 on the one side to be bonded and the second electrode 2-2 on the other side bonded to the common electrode pad are formed, and the one side to be bonded to the third individual electrode pad An LED chip group including a third LED chip on which a third electrode on the other side and a third electrode on the other side bonded to the common electrode pad are formed;
The first LED chip, the second LED chip, and the third LED chip of the LED chip group are respectively input power through the first individual electrode pad, the second individual electrode pad, and the third individual electrode pad. A display module which is individually connected and connected to the common electrode pad and can be independently controlled.   In the LED chip group, the first LED chip, the second LED chip, and the third LED chip emit light of different wavelengths, respectively, and are arranged in a matrix at the same height on the substrate. The display module according to claim 1. The LED chip group is plural,
The display module according to claim 1, wherein a horizontal interval and a vertical interval of each of the plurality of LED chip groups are the same.   The horizontal and vertical intervals of the electrode patterns formed on the substrate are the same so that the first LED chip, the second LED chip, and the third LED chip are arrayed at a predetermined interval. The display module according to claim 1, wherein the display module is formed.   The first individual electrode pad, the second individual electrode pad, and the third individual electrode pad are constant so that the first LED chip, the second LED chip, and the third LED chip are arrayed at a predetermined interval. The display module according to claim 1, wherein the display modules are arranged side by side.   The display module according to claim 1, wherein the plurality of electrode patterns are formed to have a certain pattern and a certain height.   The common electrode pad includes a first branch, a second branch, and a third branch to which the first-2 electrode, the second-2 electrode, and the third-2 electrode are connected, respectively. The display module according to claim 1.   8. The display module according to claim 7, wherein each of the first branch, the second branch, and the third branch is a region to which a bonding bump on the other side of the LED chip is bonded.   The first individual electrode pad, the second individual electrode pad, and the third individual electrode pad are regions to which bonding bumps on one side of the LED chip are bonded. Display module.   The first individual electrode pad, the second individual electrode pad, and the third individual electrode pad are one end that coincides with the second edge line, and the other adjacent to the common electrode pad on the opposite side. The display module according to claim 1, comprising a side end portion and a side portion parallel to the lateral direction. The display module according to claim 1, wherein the substrate is a rigid type having a flat surface or a flexible type.

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