Method for manufacturing a light-emitting device package and method for manufacturing a display panel using the same

Abstract

A method of manufacturing a light-emitting device package and a method of manufacturing a display panel. The method of manufacturing the light-emitting device package includes: forming a semiconductor stack on a substrate such that the semiconductor stack has a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; forming a trench having a predetermined depth in the substrate by etching through the semiconductor stack in a direction of a first surface of the substrate to separate the semiconductor stack into semiconductor light emitters separated from each other; forming a molded member that fills the trench and insulates the semiconductor light emitters from each other by applying a flexible insulating material to cover the semiconductor light emitters; forming a recess that is separated from each other by the molded member and respectively covers the semiconductor light emitters by removing the substrate; and forming a wavelength converter in the recess.

Description

[0001] Cross - reference to related applications

[0002] Korean Patent Application No. 10 - 2019 - 0081599, entitled "Method of Manufacturing a Light - Emitting Device Package and Method of Manufacturing a Display Panel Using the Same", filed on Jul. 5, 2019 with the Korean Intellectual Property Office is hereby incorporated by reference in its entirety. Technical field

[0003] Embodiments relate to a method of manufacturing a light - emitting device package and a method of manufacturing a display panel using the same. Background art

[0004] Semiconductor light - emitting diodes (LEDs) have been used as light sources for various electronic products as well as light sources for lighting devices. For example, semiconductor LED devices can be used as light sources for various types of display panels such as TVs, mobile phones, PCs, laptop PCs, and PDAs. Summary of the invention

[0005] Embodiments can be achieved by providing a method of manufacturing a light - emitting device package, the method including: forming a semiconductor stack on a first surface of a substrate having a first surface and a second surface opposite the first surface such that the semiconductor stack has a first - conductive semiconductor layer, an active layer, and a second - conductive semiconductor layer; forming a trench having a predetermined depth in the substrate by etching through the semiconductor stack in a direction of the first surface of the substrate to separate the semiconductor stack into a plurality of semiconductor light emitters separated from each other; forming a molding that fills the trench and insulates the plurality of semiconductor light emitters from each other by applying a flexible insulating material to cover the plurality of semiconductor light emitters; forming a plurality of grooves separated from each other by the molding and respectively covering the plurality of semiconductor light emitters by removing the substrate; and forming a plurality of wavelength converters in the plurality of grooves.

[0006] Embodiments can be achieved by providing a method of manufacturing a light - emitting device package, the method including: forming a plurality of semiconductor light emitters separated from each other by stacking a first - conductive semiconductor layer, an active layer, and a second - conductive semiconductor layer on a substrate and etching the first - conductive semiconductor layer, the active layer, and the second - conductive semiconductor layer to expose regions of the substrate; forming a molding including a material of polyimide (PI), poly(1,4 - cyclohexanedimethylene terephthalate) (PCT), or epoxy molding compound (EMC) such that the molding covers the plurality of semiconductor light emitters and the exposed regions of the substrate; forming a separation structure including the molding on each of the plurality of semiconductor light emitters by removing the substrate; and forming a wavelength converter in each of the grooves defined by the separation structure.

[0007] An embodiment can be implemented by providing a method of manufacturing a display panel, the method comprising: preparing a first substrate structure such that the first substrate structure includes a plurality of semiconductor light emitters having a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer on a first substrate, electrode pads respectively connected to the first conductive semiconductor layer and the second conductive semiconductor layer of the plurality of semiconductor light emitters, and a molding including a flexible material covering the plurality of semiconductor light emitters; preparing a second substrate structure including a plurality of thin film transistor (TFT) units on a second substrate, the plurality of TFT units corresponding to the plurality of semiconductor light emitters respectively; bonding the first substrate structure to the second substrate structure at a process temperature to connect the electrode pads of the first substrate structure to connection members of the second substrate structure respectively; forming a plurality of grooves separated by the molding and respectively covering the plurality of semiconductor light emitters by removing the first substrate; and forming a plurality of wavelength converters in each of the plurality of grooves, wherein the molding is formed of a material having a modulus lower than that of the semiconductor light emitters. Description of the Drawings

[0008] Features will be apparent to those skilled in the art by referring to the accompanying drawings in detail, in which:

[0009] Figure 1 A schematic perspective view of a display panel using a light emitting device package according to an exemplary embodiment of the present disclosure is shown;

[0010] Figure 2 Shown Figure 1 A plan view of part “A” of

[0011] Figure 3 Shown Figure 2 An enlarged view of one pixel of

[0012] Figure 4 Shown taken along line Figure 3 A side cross-sectional view taken along line I-I’ of

[0013] Figure 5 A cross-sectional view of a display panel according to an exemplary embodiment of the present disclosure is shown;

[0014] Figure 6 A partial cross-sectional view of a light emitting device package according to an exemplary embodiment of the present disclosure is shown;

[0015] Figure 7 A drive circuit diagram of a display panel using a light emitting device package according to an exemplary embodiment of the present disclosure is shown;

[0016] Figures 8 to 16 Shown for manufacturing Figure 4 A schematic diagram of each stage in the method of the display panel of

[0017] Figures 17 to 21 Schematic diagrams showing the stages in a method of manufacturing Figure 5 a display panel. Detailed implementation manners

[0018] Figure 1 Schematic plan view showing a display panel having a light-emitting device package according to an exemplary embodiment of the present disclosure, Figure 2 showing Figure 1 a plan view of part “A” of Figure 3 showing Figure 2 an enlarged view of one pixel of Figure 4 showing a side cross-sectional view taken along line I-I’ of Figure 3

[0019] Referring to Figure 1 , a display panel 1 according to an exemplary embodiment of the present disclosure may include: a first substrate structure 100 including a light-emitting element array; and a second substrate structure 300 on a lower portion of the first substrate structure 100 and including a driving circuit. A protective layer 400 may be on an upper surface of the first substrate structure 100, and a bonding layer 200 may be between the first substrate structure 100 and the second substrate structure 300. The display panel 1 may have a rectangular shape or another suitable shape. The display panel 1 may have flexible characteristics. For example, in addition to a flat surface, an upper surface of the display panel 1 may have a profile with a curved surface. In an implementation, the display panel 1 may be an ultra-compact and high-resolution display panel for a head-mounted headset for virtual reality or augmented reality.

[0020] Referring to Figure 2 , the first substrate structure 100 may include a pixel region 10 and a molding region 20 surrounding the pixel region 10. In the pixel region 10, a plurality of pixels P may be arranged in columns and rows. In an implementation, as shown in the drawings, a plurality of pixels P may be formed in a 15×15 rectangular array. In an implementation, the number of columns and rows may be implemented as a suitable number (e.g., 1024×768, 1920×1080, 3840×2160, and 7680×4320), and a plurality of pixels may be arranged in various shapes other than a rectangle. The plurality of pixels P may be connected to each other. For example, the plurality of pixels P may not be manufactured individually, but may be manufactured as a whole in the same operation at one time.

[0021] The molding region 20 may be around the pixel region 10 (e.g., may surround the pixel region 10). The molding region 20 may include (e.g., black) a substrate. For example, the black substrate may be in the peripheral region of the first substrate structure 100 to be used as a guiding line for defining the region where a plurality of pixels P are arranged. The substrate may not be black. In an embodiment, depending on the intended purpose or use of the product, a white substrate or a green substrate may be used as the substrate, and if necessary, a substrate formed of a transparent material may be used instead of the substrate.

[0022] Figure 3 shows a pixel P, Figure 4 shows a cross-sectional structure of a pixel P. Figure 4 The first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3 may be understood to correspond to the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3, respectively.

[0023] Referring to Figure 3 and, each pixel P may include a first sub-pixel SP1, a second sub-pixel SP2, and a third sub-pixel SP3 configured to emit light of different colors. The first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3 included in each pixel P may have a structure in which the sub-pixels are adjacent to each other. The first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3 may be configured to provide different colors, and thus a color image may be presented through the display panel 1. For example, the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3 may be sub-pixels that respectively emit light having red (R), green (G), and blue (B). In an embodiment, various colors may be used, such as cyan, yellow, magenta, and black (CYMK). In an embodiment, one pixel P may include three sub-pixels corresponding to RGB respectively. In an embodiment, the pixel P may include four or more sub-pixels. In an embodiment, the three sub-pixels may be arranged side by side. Each of the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3 may have a width (in the first direction) W1 of about 1 μm and a length (in the second direction perpendicular to the first direction) L1 of about 3 μm, so that the width W2 and the length L2 of the pixel P may have a size that allows the pixel density to be equal to or greater than 8000 pixels per inch (PPI).

[0024] Referring to Figure 3 and Figure 4 and, one pixel P may include a first substrate structure 100 and a second substrate structure 300 stacked vertically. The first substrate structure 100 and the second substrate structure 300 may be joined by a joining layer 200.

[0025] The protective layer 400 can be bonded to the upper part of the first substrate structure 100 (e.g., the side of the first substrate structure 100 facing away from the second substrate structure 300). The first substrate structure 100 and the second substrate structure 300 can be bonded to each other for integration using a wafer bonding method such as wafer-level fusion bonding.

[0026] The first substrate structure 100 can include a light-emitting device package LK1, which includes a first semiconductor light emitter LED1, a second semiconductor light emitter LED2, and a third semiconductor light emitter LED3. The light-emitting device package LK1 can include a first electrode pad 170N and a second electrode pad 170P connected to each of the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3, an insulating layer 161 covering the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3, a reflective layer 162 that reflects the light emitted by the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3 while covering the insulating layer 161, a first wavelength converter 190R, a second wavelength converter 190G, and a third wavelength converter 190B respectively disposed on the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3, and a molding member 180 that separates the first wavelength converter 190R, the second wavelength converter 190G, and the third wavelength converter 190B from each other and encapsulates the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3. The first electrode pad 170N and the second electrode pad 170P can be formed of a conductive material such as metal.

[0027] The light-emitting device package LK1 may include a first semiconductor light emitter LED1, a second semiconductor light emitter LED2, and a third semiconductor light emitter LED3, and each of the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3 may include a semiconductor stack 130 in which epitaxial layers such as a first conductive semiconductor layer 131, an active layer 132, and a second conductive semiconductor layer 133 are stacked. A buffer layer 120 for reducing the lattice constant difference between the epitaxial layer and the substrate may be on the first conductive semiconductor layer 131. Each epitaxial layer may be grown using the same operations on one wafer. For example, the active layers 132 of the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3 may emit the same light. In an embodiment, the active layer 132 may emit blue light (e.g., 440 nm to 460 nm). The first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3 may have the same structure. An insulating layer 142 may be on the lower surface of the second conductive semiconductor layer 133, and an ITO layer 141 (for improving the contact property of the second conductive semiconductor layer 133) may be between the insulating layer 142 and the second conductive semiconductor layer 133.

[0028] The first conductive semiconductor layer 131 and the second conductive semiconductor layer 133 may be an n-type semiconductor layer and a p-type semiconductor layer, respectively. In an embodiment, the semiconductor layer may be Al x In y Ga (1-x-y) N (where 0 ≤ x ≤ 1, 0 ≤ y ≤ 1, and 0 ≤ x + y ≤ 1) nitride semiconductor. The active layer 132 may have a multi-quantum well (MQW) structure in which quantum well layers and quantum barrier layers are stacked alternately. In an embodiment, the active layer 132 may be a nitride-based MQW such as InGaN / GaN or GaN / AlGaN. In an embodiment, the active layer 132 may be another semiconductor such as GaAs / AlGaAs, InGaP / GaP, or GaP / AlGaP. As used herein, the term "or" is not an exclusive term. For example, "A or B" will include A, B, or both A and B.

[0029] The insulating layer 161 may be included in the lower part of the light-emitting device package LK1, and the insulating layer 161 may surround each of the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3 to allow the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3 to be electrically separated from each other. The insulating layer 161 may extend to cover the side surfaces of the first wavelength converter 190R, the second wavelength converter 190G, and the third wavelength converter 190B. The insulating layer 161 may be formed of a material having electrical insulating properties. In an embodiment, the insulating layer 161 may be silicon oxide, silicon oxynitride, or silicon nitride. In an embodiment, a reflective layer 162 formed of a highly reflective material may be on the insulating layer 161. In an embodiment, the reflective layer 162 may be formed of aluminum (Al). The insulating layer 161 and the reflective layer 162 may help block optical interference between the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3.

[0030] Each of the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3 may include a first electrode 150N and a second electrode 150P that apply electric power to the first conductive semiconductor layer 131 and the second conductive semiconductor layer 133, respectively. The first electrode 150N and the second electrode 150P may be in the mesa etching regions of the first conductive semiconductor layer 131 and the second conductive semiconductor layer 133, respectively. In an embodiment, the first electrode 150N may include, for example, Al, Au, Cr, Ni, Ti, or Sn, and the second electrode 150P may be formed of a reflective metal. In an embodiment, the second electrode 150P may include, for example, Ag, Ni, Al, Cr, Rh, Pd, Ir, Ru, Mg, Zn, Pt, or Au, and may be configured as a structure having a single layer or two or more layers.

[0031] Each of the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3 may include a first electrode pad 170N and a second electrode pad 170P for applying electric power. The first electrode pad 170N and the second electrode pad 170P may be connected to the first electrode 150N and the second electrode 150P, respectively.

[0032] The first substrate structure 100 may include a molding member 180 that exposes the first electrode pad 170N and the second electrode pad 170P while encapsulating the lower surface of the light-emitting device package LK1. For example, the molding member 180 may have partition walls protruding between the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3 to allow the first wavelength converter 190R, the second wavelength converter 190G, and the third wavelength converter 190B to be separated from each other.

[0033] The molding member 180 may be formed of a material having a low modulus, thereby allowing the first substrate structure 100 to have flexible characteristics. For example, the molding member 180 may be formed of a material having a modulus lower than that of the semiconductor stack 130 and having high tensile properties. In an embodiment, the molding member 180 may include, for example, polyimide (PI), polycyclohexylene dimethylene terephthalate (PCT), or an epoxy molding compound (EMC). In an embodiment, the molding member 180 may include light-reflecting particles for reflecting light. In an embodiment, the light-reflecting particles may include, for example, titanium dioxide (TiO2) or aluminum oxide (Al2O3).

[0034] The molding member 180 may have or form partition walls around the side surfaces of the first wavelength converter 190R, the second wavelength converter 190G, and the third wavelength converter 190B to separate the first wavelength converter 190R, the second wavelength converter 190G, and the third wavelength converter 190B from each other. The side walls of the molding member 180 may, for example, protrude upward at each of the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3 to form a first light emission window X1, a second light emission window X2, and a third light emission window X3, thereby filling the first wavelength converter 190R, the second wavelength converter 190G, and the third wavelength converter 190B, respectively. The first wavelength converter 190R, the second wavelength converter 190G, and the third wavelength converter 190B may be in the first light emission window X1, the second light emission window X2, and the third light emission window X3, respectively. For example, the light emitted by the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3 may not be subject to optical interference and may be emitted through the first wavelength converter 190R, the second wavelength converter 190G, and the third wavelength converter 190B.

[0035] For example, wavelength conversion materials (e.g., quantum dots (QDs)) can be filled in the first light emission window X1, the second light emission window X2, and the third light emission window X3 of the molded part 180, and can be dispersed in a liquid binder resin, and then can be cured to form a first wavelength converter 190R, a second wavelength converter 190G, and a third wavelength converter 190B. In an embodiment, at least one of the first wavelength converter 190R, the second wavelength converter 190G, and the third wavelength converter 190B can include only the binder resin without the wavelength conversion material. In an embodiment, the first wavelength converter 190R and the second wavelength converter 190G include quantum dots QD1 and QD2 for wavelength conversion from blue light to red light and green light, and the third wavelength converter 190B can include only the binder resin without separate quantum dots.

[0036] A liquid photosensitive resin composition in which the red quantum dots QD1 and the green quantum dots QD2 are dispersed in a binder resin can be filled in the first light emission window X1 and the second light emission window X2, and then cured to form the first wavelength converter 190R and the second wavelength converter 190G. A liquid photosensitive resin composition that does not include quantum dots is filled in the third light emission window X3 and then cured to form the third wavelength converter 190B. The binder resin can be formed of a material including an acrylic polymer.

[0037] A protective layer 400 (e.g., which can help prevent the first wavelength converter 190R, the second wavelength converter 190G, and the third wavelength converter 190B from deteriorating) can be on the upper part of the first wavelength converter 190R, the second wavelength converter 190G, and the third wavelength converter 190B.

[0038] A bonding layer 200 bonded to the second substrate structure 300 can be on the lower part of the first substrate structure 100 (e.g., between the first substrate structure 100 and the second substrate structure 300). The bonding layer 200 can include an insulating bonding layer 210 and a conductive bonding layer 220.

[0039] The insulating bonding layer 210 can facilitate bonding of the first substrate structure 100 to the second substrate structure 300. The insulating bonding layer 210 can be formed of a material having the same composition as the molded part 180 of the first substrate structure 100. The conductive bonding layer 220 can facilitate bonding of the first electrode pad 170N and the second electrode pad 170P of the first substrate structure 100 to the contacts of the second substrate structure 300, and can be formed of a conductive material having the same composition as the first electrode pad 170N and the second electrode pad 170P. For example, the first substrate structure 100 and the second substrate structure 300 can be bonded to each other through the bonding layer 200 and integrated.

[0040] The second substrate structure 300 may include a driving circuit, which includes a plurality of TFT units for controlling the light-emitting device package LK1 of the first substrate structure 100. The plurality of TFT units may form a TFT circuit for controlling the driving of a plurality of pixels P. The plurality of TFT units may be respectively connected to the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3 through the conductive bonding layer 220 of the bonding layer 200. The plurality of TFT units may include a semiconductor layer formed by implanting impurities into a semiconductor substrate. For example, the semiconductor layer forming the plurality of TFT units may include a polysilicon semiconductor or a silicon semiconductor, a semiconductor oxide such as indium gallium zinc oxide, or a compound semiconductor such as silicon germanium.

[0041] Figure 5 A cross-sectional view of a display panel having a light-emitting device package according to an exemplary embodiment of the present disclosure is shown.

[0042] Referring to Figure 5 FIG. 2, the display panel 2 according to an exemplary embodiment of the present disclosure may include a first sub-pixel SP11, a second sub-pixel SP12, and a third sub-pixel SP13. The display panel 2 may include a first substrate structure 1100 and a second substrate structure 1300. The first substrate structure 1100 and the second substrate structure 1300 may be bonded through a bonding layer 1200. A protective layer 1400 may be on the upper surface of the first substrate structure 1100. The first substrate structure 1100 may include a light-emitting device package LK2, which includes a first semiconductor light emitter LED11, a second semiconductor light emitter LED12, and a third semiconductor light emitter LED13. The light-emitting device package LK2 may include a first electrode pad 1170N and a second electrode pad 1170P, a first wavelength converter 1190R, a second wavelength converter 1190G, and a third wavelength converter 1190B, a first molding 1161, and a second molding 1180. Each of the first semiconductor light emitter LED11, the second semiconductor light emitter LED12, and the third semiconductor light emitter LED13 may include a semiconductor stack 1130, in which epitaxial layers such as a first conductive semiconductor layer 1131, an active layer 1132, and a second conductive semiconductor layer 1133 are stacked. A buffer layer 1120 may be on the first conductive semiconductor layer 1131. An insulating layer 1142 may be on the lower surface of the second conductive semiconductor layer 1133, and an indium tin oxide (ITO) layer 1141 may be between the insulating layer 1142 and the second conductive semiconductor layer 1133. The bonding layer 1200 may include an insulating bonding layer 1210 and a conductive bonding layer 1220. A third electrode pad 1190N and a fourth electrode pad 1190P may be respectively connected to the first electrode pad 1170N and the second electrode pad 1170P. The second molding 1180 may surround the side surfaces of the third electrode pad 1190N and the fourth electrode pad 1190P.

[0043] When comparing the display panel 2 of Figure 5 with the display panel 1 according to the previously described exemplary embodiment, the differences are that the molded part may include a first molded part 1161 and a second molded part 1180, and the reflective layer according to the previously described exemplary embodiment and the insulating layer for insulating the reflective layer from each of the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3 are removed.

[0044] In an embodiment, the first molded part 1161 may be formed of, for example, polycyclohexylene dimethylene terephthalate (PCT) having a high reflectivity and a white epoxy molding compound (white EMC). For example, even if the additional reflective layer is omitted, a sufficient light reflection effect can be expected only by the first molded part 1161. The above materials have a melting point equal to or less than 230 °C, so the first molded part 1161 can be melted in a bonding process performed at a temperature equal to or higher than 350 °C. For example, if the first molded part 1161 is to be melted, its appearance will be deformed and it will lose its function as a molded part. In an embodiment, on the lower part of the first molded part 1161 (e.g., near the second substrate structure 1300), a material layer such as polyimide (PI) (e.g., a material that will not be melted in the bonding process) may be added or included as the second molded part 1180. For example, even if the first molded part 1161 is melted in the bonding process, its appearance can be maintained, so its function as a molded part can also be maintained.

[0045] Figure 6 shows a variant of the previously described light-emitting device package, and Figure 6 the light-emitting device package of Figure 6The light-emitting device package can be modified such that the semiconductor stack 2130 included in a single semiconductor light emitter LED23 has a first region LEDa and a second region LEDb that share a first conductive semiconductor layer 2131. Correspondingly, the second electrode pad 2170P can also be divided into two second electrode pads 2170PA and 2170PB. For example, the semiconductor light emitter LED23 having the first region LEDa and the second region LEDb to be independently driven can be in a single sub-pixel SP14. As described above, the semiconductor light emitter LED23 having the first region LEDa and the second region LEDb can selectively supply power to the first region LEDa and the second region LEDb using a driving circuit to be described later. For example, if a problem occurs in one of the first region LEDa and the second region LEDb and this one region does not operate properly, automatic switching to the other region can be performed. For example, the lifespan of the light-emitting device package can be extended. If a problem occurs in a part of the driving circuit for controlling one of the first region LEDa and the second region LEDb, automatic switching to the driving circuit for controlling the other region can be performed. For example, the lifespan of the light-emitting device package can be extended.

[0046] Figure 7 shows Figure 6 The driving circuit of the light-emitting device package shown. The two regions LEDa and LEDb forming a single sub-pixel can be driven by separate driving circuits DC1 and DC2 to which a power supply voltage ELVDD is applied, respectively. Each of the two regions LEDa and LEDb can receive a data signal through a data line Data and can be turned on / off controlled through a scan line Scan. The above driving circuit can be implemented using an integrated circuit and / or a thin film transistor circuit.

[0047] Hereinafter, a process of manufacturing a display panel according to an exemplary embodiment will be described. Figures 8 to 16 shows Figure 4 Schematic diagrams of the respective stages in the method of manufacturing the display panel shown.

[0048] First, referring to Figure 8 , a buffer layer 120 can be formed on a substrate 110, and a semiconductor stack 130 can be formed on the buffer layer 120. The substrate 110 can include, for example, sapphire, Si, SiC, MgAl2O4, MgO, LiAlO2, LiGaO2, GaN, etc. In an embodiment, the substrate 110 can be at least 10 19 atoms / cm 3The concentration is doped with boron to help ensure the etching selectivity in subsequent processes. The semiconductor stack 130 can be formed by sequentially growing a first conductive semiconductor layer 131, an active layer 132, and a second conductive semiconductor layer 133 on the substrate 110 through processes such as metal-organic chemical vapor deposition (MOCVD), hydride vapor phase epitaxy (HVPE), or molecular beam epitaxy (MBE). The first conductive semiconductor layer 131 and the second conductive semiconductor layer 133 can be an n-type semiconductor layer and a p-type semiconductor layer, respectively. An ITO layer 141 (for improving the contact characteristics of the second conductive semiconductor layer 133) can be formed on the semiconductor stack 130.

[0049] Referring to Figure 9 , in order to expose at least a part of the first conductive semiconductor layer 131, a partial region E of the semiconductor stack 130 can be etched to form a mesa region M.

[0050] Referring to Figure 10 and Figure 11 , an insulating layer 142 covering the upper surface of the semiconductor stack 130 can be formed, a partial region thereof can be removed to form contact holes H1 and H2 exposing the first conductive semiconductor layer 131 and the second conductive semiconductor layer 133, and first electrodes 150N and second electrodes 150P can be formed in the contact holes H1 and H2.

[0051] Referring to Figure 12 , a trench T separating the semiconductor stack 130 into a first semiconductor light emitter LED1, a second semiconductor light emitter LED2, and a third semiconductor light emitter LED3 can be provided. The trench T can etch not only the semiconductor stack 130 but also a partial region of the substrate 110 to a predetermined depth D. In the trench T, a partition wall structure filled with a molding to separate the wavelength converter can be formed in a subsequent process.

[0052] Referring to Figure 13 , an insulating layer 161 covering the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3 and a reflective layer 162 covering the insulating layer 161 can be formed.

[0053] Referring to Figure 14, a plating layer may be formed on the first electrode 150N and the second electrode 150P to form the first electrode pad 170N and the second electrode pad 170P, and a molding 180 may be formed to cover the side surfaces of the first electrode pad 170N and the second electrode pad 170P. The molding 180 may fill the trench T to isolate the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3 from each other. The molding 180 may be formed of a material having a low modulus to have a flexible characteristic. In an embodiment, the molding 180 may be formed of a material having a modulus lower than that of the semiconductor stack 130 and having high tensile properties. In an embodiment, the molding 180 may include, for example, polyimide (PI), polycyclohexylene dimethylene terephthalate (PCT), or epoxy molding compound (EMC).

[0054] Referring Figure 15 , the second substrate structure 300 may be attached to the lower portion of the molding 180, and the bonding layer 200 is located between the second substrate structure 300 and the lower portion of the molding 180. The second substrate structure 300 may include a driving circuit including a plurality of TFT units for controlling the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3. The plurality of TFT units may include semiconductor layers formed by implanting impurities into a semiconductor substrate. For example, the semiconductor layers forming the plurality of TFT units may include polysilicon semiconductors or silicon semiconductors, semiconductor oxides such as indium gallium zinc oxide, or compound semiconductors such as silicon germanium. The semiconductor substrate may be doped with boron at a concentration equal to or less than 10 16 atoms / cm 3 (e.g., a concentration lower than the doping concentration on the substrate 110) to help ensure etch selectivity in subsequent processes for separating the substrate 110 for growth.

[0055] Referring Figure 16 , the substrate 110 may be separated from the first semiconductor light emitter LED1, the second semiconductor light emitter LED2, and the third semiconductor light emitter LED3, and grooves H5R, H5G, and H5B defined by the partition wall structure may be provided when viewed from the top. Subsequently, wavelength conversion materials (e.g., quantum dots (QD)) are filled in the grooves H5R, H5G, and H5B while being dispersed in a liquid binder resin to form the first wavelength converter 190R, the second wavelength converter 190G, and the third wavelength converter 190B, and the protective layer 400 may be attached to the upper portion to manufacture Figure 4 the display panel 1.

[0056] A process of manufacturing a display panel according to an exemplary embodiment will be described. Figures 17 to 21 Illustrates the manufacture of Figure 5Schematic diagrams of various stages in the method of the display panel. Figure 17 The processes before are the same as those up to the previously described exemplary embodiments Figure 12 of the process, and the repeated description of the process can be omitted.

[0057] Referring to Figure 17 , a plating layer is formed on the first electrode 1150N and the second electrode 1150P to form the first electrode pad 1170N and the second electrode pad 1170P.

[0058] Referring to Figure 18 , a first molding 1161 (covering the side surfaces of the first electrode pad 1170N and the second electrode pad 1170P) can be formed. The first molding 1161 can fill the trench T to isolate the first semiconductor light emitter LED11, the second semiconductor light emitter LED12, and the third semiconductor light emitter LED13 from each other. The first molding 1161 can be formed of a material with a low modulus to have flexible characteristics, and can be formed of a material with a modulus lower than that of the semiconductor stack 1130 and having high tensile properties. In an embodiment, the first molding 1161 can be formed of, for example, PCT or white EMC. Compared with PI (for example, the material used as the molding in the above exemplary embodiments), PCT and white EMC have excellent reflectivity. For example, a separate reflective layer for reflecting light emitted from the first semiconductor light emitter LED11, the second semiconductor light emitter LED12, and the third semiconductor light emitter LED13 can be omitted.

[0059] Referring to Figure 19 , a second molding 1180 (formed of a material including PI) can be formed on the first molding 1161. The melting point of the first molding 1161 (for example, formed of a material including PCT or white EMC) can be equal to or less than 230 °C, and the first molding can be melted in a subsequent process in which bonding is performed at a temperature equal to or higher than 350 °C, thus losing its function as a molding. For example, a second molding 1180 (formed of PI with a melting point higher than that of PCT or white EMC) can be formed on the first molding 1161 (formed of PCT and white EMC). In this case, even if the first molding 1161 is melted due to the heat of the bonding process, the appearance can be maintained due to the second molding 1180.

[0060] Referring to Figure 20, the second substrate structure 1300 may be attached to the lower portion of the second molding 1180, and the bonding layer 120 is located between the second substrate structure 1300 and the lower portion of the second molding 1180. The second substrate structure 1300 may include a driving circuit, which includes a plurality of TFT units for controlling the first semiconductor light emitter LED11, the second semiconductor light emitter LED12, and the third semiconductor light emitter LED13.

[0061] Referring to Figure 21 , the substrate 1110 may be separated from the first semiconductor light emitter LED11, the second semiconductor light emitter LED12, and the third semiconductor light emitter LED13, and grooves H6R, H6G, and H6B (e.g., defined by the partition wall structure when viewed from the top) may be provided. Subsequently, wavelength conversion materials (e.g., quantum dots (QDs)) may be filled in the grooves H6R, H6G, and H6B while being dispersed in a liquid binder resin to form wavelength converters 1190R, 1190G, and 1190B, and a protective layer 1400 may be attached to the upper portion to fabricate Figure 5 the display panel 2.

[0062] By summarizing and reviewing, some display panels may include a liquid crystal display (LCD) panel and a backlight unit; and, display devices that do not require an additional backlight by using LED devices as individual pixels are being developed. Compared with LCDs, these display panels may be compact and may be implemented as high-brightness displays with improved optical efficiency. The display panel may also allow the aspect ratio of the displayed image to be freely changed and may be implemented as a large display panel, thereby providing various forms of large displays. However, the partition wall structure therein may limit the resolution.

[0063] As described above, according to an exemplary embodiment, by using a method of manufacturing a light-emitting device package and a method of manufacturing a display panel using the same, an increased pixel density may be achieved, it may be flexible, the manufacturing cost may be reduced, and the sizes of the light-emitting device package and the display panel may be reduced.

[0064] For example, one or more embodiments may provide a method of manufacturing a light-emitting device package and a method of manufacturing a display panel, by using which the manufacturing cost may be reduced and miniaturization may be promoted.

[0065] One or more embodiments may provide a display panel that is flexible and has an increased pixel density or a method of manufacturing the display panel.

[0066] Example embodiments have been disclosed herein. Although specific terms are employed, they are used and interpreted in a general and descriptive sense only and not for purposes of limitation. In some instances, as will be apparent to those of ordinary skill in the art, features, characteristics, and / or elements described in connection with a particular embodiment may be used singly or in combination with features, characteristics, and / or elements described in connection with other embodiments, since the filing of this application, unless specifically indicated otherwise. Accordingly, those skilled in the art will appreciate that various forms and details may be changed without departing from the spirit and scope of the invention as set forth in the appended claims.

Claims

1. A method of manufacturing a light-emitting device package, the method comprising the steps of: forming a semiconductor stack on a first surface of a substrate having a first surface and a second surface opposite the first surface, such that the semiconductor stack has a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; separating the semiconductor stack into a plurality of semiconductor light emitters separated from each other by forming a trench having a predetermined depth in the substrate by etching through the semiconductor stack in a direction of the first surface of the substrate; forming a molded member that fills the trench and insulates the plurality of semiconductor light emitters from each other by coating a flexible insulating material to cover the plurality of semiconductor light emitters; forming a plurality of grooves that are separated from each other by the molded member and respectively cover the plurality of semiconductor light emitters by removing the substrate; and forming a plurality of wavelength converters in the plurality of grooves; wherein forming the molded member includes: forming a first molded member that fills the trench, the first molded member being formed of a material including cyclohexanedimethanol terephthalate and a white epoxy molding compound and serving as a partition wall structure for separating the plurality of wavelength converters; and forming a second molded member that covers the first molded member, the second molded member being formed of a material including polyimide.

2. The method for manufacturing a light-emitting device package according to claim 1, wherein, The flexible insulating material is a material having a modulus lower than the modulus of the semiconductor stack.

3. The method of manufacturing a light-emitting device package according to claim 1, wherein, The plurality of semiconductor light emitters and the plurality of wavelength converters respectively correspond to each other to form a plurality of sub-pixels, and one pixel including the plurality of sub-pixels has a pixel density of 8000 pixels per inch.

4. The method of manufacturing a light-emitting device package according to claim 1, wherein, The step of forming the semiconductor stack further includes: sequentially stacking an indium tin oxide layer and an insulating layer on the second conductive semiconductor layer.

5. The method of manufacturing a light-emitting device package according to claim 1, wherein: The second molded member is formed of a material having a melting point higher than the melting point of the first molded member.

6. The method of manufacturing a light-emitting device package according to claim 1, further comprising the steps of: forming an indium tin oxide layer on the second conductive semiconductor layer before separating the semiconductor stack into a plurality of semiconductor light emitters; and forming an insulating layer on the indium tin oxide layer.

7. A method of manufacturing a light-emitting device package, the method comprising the steps of: forming a plurality of semiconductor light emitters separated from each other by stacking a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer on a substrate and etching the first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer to expose an area of the substrate; forming a molded member of a material including polyimide, cyclohexanedimethanol terephthalate, or an epoxy molding compound, such that the molded member covers the plurality of semiconductor light emitters and the exposed area of the substrate; forming a partition structure including the molded member on each of the plurality of semiconductor light emitters by removing the substrate; and forming a wavelength converter in each of the grooves defined by the partition structure; wherein forming the molded member includes: Form a first molded part that fills the trench, the first molded part being formed of a material including cyclohexanedimethanol terephthalate and a white epoxy molding compound, and serving as a partition wall structure for separating the plurality of wavelength converters; and Form a second molded part that covers the first molded part, the second molded part being formed of a material including polyimide.

8. A method of manufacturing a display panel, the method including the steps of: Prepare a first substrate structure such that the first substrate structure includes: A plurality of semiconductor light emitters having a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer on a first substrate, Electrode pads respectively connected to the first conductive semiconductor layer and the second conductive semiconductor layer of the plurality of semiconductor light emitters, and A molded part including a flexible material covering the plurality of semiconductor light emitters; Prepare a second substrate structure including a plurality of thin film transistor units on a second substrate, the plurality of thin film transistor units respectively corresponding to the plurality of semiconductor light emitters; Bond the first substrate structure to the second substrate structure at a process temperature to connect the electrode pads of the first substrate structure to the connectors of the second substrate structure respectively; Form a plurality of grooves that are separated by the molded part and respectively cover the plurality of semiconductor light emitters by removing the first substrate; And Form a plurality of wavelength converters in each of the plurality of grooves, Wherein the molded part is formed of a material having a modulus lower than that of the semiconductor light emitter, Wherein the molded part includes a first molded part that fills the trench separating the plurality of semiconductor light emitters and a second molded part that covers the first molded part, the first molded part being formed of a material including cyclohexanedimethanol terephthalate and a white epoxy molding compound, and serving as a partition wall structure for separating the plurality of wavelength converters, the second molded part being formed of a material including polyimide.

9. The method of manufacturing a display panel according to claim 8, wherein: The first substrate and the second substrate are formed of a semiconductor substrate, and The first substrate and the second substrate have different etching selectivities from each other.

10. The method of manufacturing a display panel according to claim 9, wherein, The first substrate is doped with boron at a concentration higher than the concentration of boron doped in the second substrate.

11. The method of manufacturing a display panel according to claim 8, wherein, Each of the plurality of semiconductor light emitters emits light having substantially the same wavelength.

12. The method of manufacturing a display panel according to claim 8, wherein, Each of the plurality of semiconductor light emitters has substantially the same size.

13. The method of manufacturing a display panel according to claim 8, wherein: The plurality of semiconductor light emitters and the plurality of wavelength converters respectively correspond to each other to form a plurality of sub-pixels, and One pixel including the plurality of sub-pixels has a density equal to or greater than 8000 pixels per inch.

14. The method of manufacturing a display panel according to claim 8, wherein: The plurality of semiconductor light emitters include a plurality of second conductive semiconductor layers that are separated from each other, and The plurality of second conductive semiconductor layers share the first conductive semiconductor layer.

15. The method of manufacturing a display panel according to claim 14, wherein, Each of the plurality of second conductive semiconductor layers receives electric power selectively applied by respective electrode pads.

16. The method of manufacturing a display panel according to claim 8, wherein: the first molding covers the plurality of semiconductor light emitters, the second molding is formed of a material having a melting point higher than that of the first molding, and the melting point of the second molding is higher than the process temperature at which the first substrate structure is bonded to the second substrate structure.

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