Wafer-level packaging method and packaging structure of OLED (Organic Light Emitting Diode) chip

Abstract

The invention provides a wafer-level packaging method and packaging structure of an OLED chip, and relates to the technical field of semiconductor packaging. The wafer-level packaging method of the OLED chip comprises the following steps: providing a light-transmitting cover plate and a wafer; wherein the wafer is provided with a plurality of light-emitting areas, the peripheries of the light-emitting areas are provided with electrodes, and preset intervals are arranged between the electrodes and the light-emitting areas. A plurality of grooves are formed in one side of the light-transmitting cover plate, and the depth of the grooves is smaller than the thickness of the light-transmitting cover plate; and mounting parts are formed among the plurality of grooves. Bonding the wafer and the light-transmitting cover plate; wherein the light-emitting areas and the surface-mounting parts are in one-to-one correspondence and are in press fit. Cutting the light-transmitting cover plate along the edge of the mounting part, and removing the groove structure to form a wafer with a light-transmitting patch; and the projection of the light-transmitting patch on the wafer does not coincide with the electrode. And slitting the wafer to form a single chip. The method is beneficial for improving the packaging efficiency and the packaging yield.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor packaging technology, and in particular to a wafer-level packaging method and packaging structure for an OLED chip. Background Art

[0002] Existing OLED chip packaging technology typically uses a single-chip packaging method. This involves first creating a barrier around the chip using dry film or adhesive, then applying adhesive to the pre-prepared individual glass sheets, one by one, onto the chip. This method is inefficient, and the adhesive can easily overflow and contaminate the chip electrodes during the bonding process, thus affecting packaging yield. Summary of the Invention

[0003] The present invention aims to provide a wafer-level packaging method and packaging structure for OLED chips, which are beneficial to improving packaging efficiency and packaging yield.

[0004] In a first aspect, the present invention provides a wafer-level packaging method for an OLED chip, comprising: A light-transmitting cover plate and a wafer are provided respectively; wherein the wafer is provided with a plurality of light-emitting areas, electrodes are provided on the periphery of the light-emitting areas, and a preset interval is provided between the electrodes and the light-emitting areas; A plurality of grooves are formed on one side of the light-transmitting cover plate, wherein the depth of the grooves is less than the thickness of the light-transmitting cover plate; and mounting portions are formed between the plurality of grooves; Bonding the wafer and the light-transmitting cover plate; wherein the light-emitting areas correspond to the mounting portions one by one and are pressed together; Cutting the transparent cover plate along the edge of the mounting portion to remove the groove structure, thereby forming a wafer with a transparent patch; the projection of the transparent patch on the wafer does not overlap with the electrode; The wafer is diced to form individual chips.

[0005] In an optional embodiment, the step of bonding the wafer and the light-transmitting cover plate includes: forming a light-transmitting adhesive on the light-emitting area of ​​the wafer and / or the mounting portion; The wafer and the light-transmitting cover plate are pressed together, wherein the wafer is on the upper side and the light-transmitting cover plate is on the lower side.

[0006] In an optional embodiment, the step of pressing the wafer and the light-transmitting cover plate together includes: Pre-pressing the wafer and the light-transmitting cover plate at room temperature and pressure; The wafer and the light-transmitting cover plate are pressed together in a vacuum environment under heating and pressurizing conditions.

[0007] In an optional embodiment, the step of pressing the wafer and the light-transmitting cover plate together under vacuum conditions and under heating and pressurizing conditions includes: Pressing for a first preset time under the conditions of a first temperature and a first pressure, and maintaining for a second preset time; pressing at the second temperature and the second pressure for a third preset time, and maintaining the pressing for a fourth preset time; The second temperature is greater than the first temperature; the second pressure is greater than the first pressure.

[0008] In an optional embodiment, in the step of forming a plurality of grooves on one side of the light-transmitting cover plate: the grooves are formed by sandblasting or etching; If sandblasting is used, it includes at least two sandblasting processes; wherein, the first sandblasting forms the groove, and the second sandblasting grinds and corrects the groove wall of the groove; wherein the correction includes correction of the groove wall inclination angle and the groove depth.

[0009] In an optional embodiment, after the step of forming a plurality of grooves on one side of the light-transmitting cover plate, the method further includes: A drainage groove is formed on the side wall of the groove.

[0010] In an optional embodiment, in the step of forming a plurality of grooves on one side of the light-transmitting cover plate, a positioning marking portion is also formed on the side of the light-transmitting cover plate having the grooves.

[0011] In an optional embodiment, the step of bonding the wafer and the light-transmitting cover plate includes: forming a glue containing groove on the mounting portion; forming a light-transmitting adhesive on the mounting portion; The wafer and the light-transmitting cover plate are pressed together.

[0012] In an optional embodiment, after the step of forming the adhesive containing groove on the mounting portion, the method further includes: An overflow port is provided on the wall of the above-mentioned glue containing groove; the overflow port is connected with the glue containing groove and the groove.

[0013] In a second aspect, the present invention provides a packaging structure manufactured using the wafer-level packaging method for an OLED chip as described in any one of the aforementioned embodiments.

[0014] The wafer-level packaging method and packaging structure of OLED chips provided by the embodiments of the present invention have the following beneficial effects: The wafer-level packaging method for OLED chips provided by the embodiment of the present invention bonds a large piece of transparent cover plate to the wafer, and can complete the bonding and mounting of multiple chips and transparent cover plates on the wafer at one time, which is highly efficient. In addition, a groove is formed on the transparent cover plate before mounting, and the groove can accommodate excess glue overflow during the mounting process, thereby preventing excess glue overflow from diffusing to the edge of the light-emitting area of ​​the chip and contaminating the electrode. When cutting the transparent cover plate, due to the groove structure, there is a gap between the electrode and the transparent cover plate in the thickness direction, and the cutting process will not damage the electrode. In addition, the cutting thickness is relatively thin, which is conducive to improving the cutting efficiency and the tolerance of the cutting accuracy, thereby improving the packaging yield.

[0015] The packaging structure provided by the embodiment of the present invention is manufactured using the above-mentioned wafer-level packaging method for OLED chips, which is beneficial to improving packaging efficiency and packaging yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 A schematic structural diagram of a light-transmitting cover plate in a wafer-level packaging method for OLED chips provided by an embodiment of the present invention; Figure 2 A schematic diagram of a structure for forming a groove on a light-transmitting cover plate in a wafer-level packaging method for an OLED chip provided by an embodiment of the present invention; Figure 3 for Figure 2 Schematic cross-section of the EE; Figure 4 A schematic structural diagram of a side wall of a groove of a light-transmitting cover plate provided in an embodiment of the present invention; Figure 5 A schematic structural diagram of a positioning marking portion formed on a light-transmitting cover provided by an embodiment of the present invention; Figure 6 A schematic structural diagram of a transparent cover plate provided in an embodiment of the present invention having a glue-containing groove formed on the mounting portion; Figure 7 A schematic structural diagram of an overflow port formed on the mounting portion of a light-transmitting cover provided by an embodiment of the present invention; Figure 8 A schematic diagram of the structure of a wafer in the wafer-level packaging method for an OLED chip provided by an embodiment of the present invention; Figure 9A schematic diagram of the structure of forming a light-transmitting adhesive on a light-transmitting cover plate in the wafer-level packaging method of an OLED chip provided by an embodiment of the present invention; Figure 10 A schematic diagram of the structure of bonding a transparent cover plate and a wafer in the wafer-level packaging method of an OLED chip provided by an embodiment of the present invention; Figure 11 A schematic diagram of a scenario in which transparent adhesive overflows when bonding a transparent cover plate and a wafer in a wafer-level packaging method for an OLED chip provided by an embodiment of the present invention; Figure 12 A schematic diagram of a process for cutting a transparent cover plate in a wafer-level packaging method for an OLED chip provided by an embodiment of the present invention; Figure 13 A schematic diagram of a process for cutting a wafer in a wafer-level packaging method for an OLED chip provided by an embodiment of the present invention; Figure 14 A schematic diagram of the structure of chip mounting in the wafer-level packaging method of the OLED chip provided by an embodiment of the present invention.

[0018] Icons: 110-translucent cover; 111-groove; 1111-side wall; 112-mounting part; 113-drainage groove; 114-positioning mark; 115-glue holding groove; 116-overflow port; 117-translucent patch; 120-wafer; 121-light-emitting area; 122-electrode; 130-translucent glue; 131-overflow glue; 140-first cutting piece; 150-second cutting piece; 160-substrate; 161-soldering pad; 162-metal wire. DETAILED DESCRIPTION

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0021] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0022] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like indicate positions or locations based on the positions shown in the accompanying drawings, or the positions or locations in which the inventive product is typically placed when in use. These terms are intended solely to facilitate the description of the present invention and to simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third," etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0023] Furthermore, terms such as "horizontal," "vertical," and "overhanging" do not necessarily imply that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0024] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0025] The following embodiments of the present invention are described in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0026] The wafer-level packaging method and packaging structure for OLED chips proposed in the embodiments of the present invention can achieve wafer-level packaging, significantly improving efficiency compared to existing single-chip packaging. Furthermore, it can prevent adhesive overflow during the bonding process between the transparent cover plate and the wafer from contaminating the electrodes, thereby improving packaging yield.

[0027] The wafer-level packaging method of the OLED chip includes: Please combine Figure 1 Step S1: Provide a light-transmitting cover plate 110. The light-transmitting cover plate 110 may be a glass plate.

[0028] Alternatively, prepare a piece of white glass and clean it with alkaline solution and hot water to remove dirt from the surface. Depending on the size of wafer 120, the size of the white glass piece should be roughly equal to the size of wafer 120. A 6-inch to 12-inch wafer with a thickness of 100 to 1000 microns can be used.

[0029] In other embodiments, the transparent cover plate 110 may also be made of other highly transparent materials, such as transparent polymer materials, transparent thin-film composite materials, transparent ceramic materials, flexible ultra-thin glass, or other emerging materials. Transparent polymer materials include, but are not limited to, at least one or more of polyimide (PI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and cycloolefin polymer (COP). Transparent thin-film composite materials include, but are not limited to, transparent polysiloxane or a multilayer barrier film composed of alternating polymers (such as PET) and inorganic layers (aluminum oxide or silicon oxide). Transparent ceramic materials include, but are not limited to, sapphire (single crystal Al2O3) or transparent aluminum oxide (polycrystalline Al2O3). Other emerging materials include, but are not limited to, graphene films or nanocellulose films.

[0030] Please combine Figure 2 and Figure 3 In step S2 , a plurality of grooves 111 are formed on one side of the transparent cover plate 110 , wherein the depth of the grooves 111 is less than the thickness of the transparent cover plate 110 ; and mounting portions 112 are formed between the plurality of grooves 111 .

[0031] Optionally, the spacing between the plurality of grooves 111 is determined based on the distribution of the chips on the wafer 120. The grooves 111 can be formed by sandblasting or etching. Of course, laser grooving or other methods can also be used, which are not specifically limited here. In this embodiment, the formation of the grooves 111 by sandblasting is used as an example for description.

[0032] Optionally, a mask is made first. The mask is a steel plate designed with a specific pattern, and the specific pattern is designed according to the distribution of the light-emitting area 121 of the chip on the wafer 120. The mask is placed on the transparent cover 110, and the mask covers part of the transparent cover 110. The part of the transparent cover 110 exposed from the mask is the sandblasting area. A large number of small-sized steel balls are used to bombard the surface of the transparent cover 110 to form grooves 111. During the bombardment process, the depth and angle of the grooves 111 can be adjusted by adjusting the pressure and the number of steel balls. The setting of the mask can protect the non-sandblasting area on the transparent cover 110. It can be understood that the non-sandblasting area includes the gaps between the multiple grooves 111, that is, the mounting portion 112 formed.

[0033] Optionally, the angle of the groove 111 can be adjusted according to the product structure and space, generally 30° to 90°, preferably 60°. The angle of the groove 111 refers to the angle formed by the side wall 1111 of the groove 111 and the surface of the transparent cover plate 110, such as Figure 3 As shown in θ.

[0034] Optionally, the depth of the groove 111 is L, which is greater than or equal to 5 microns and less than the thickness of the transparent cover plate 110. This configuration ensures that there is sufficient clearance between the electrode 122 and the transparent cover plate 110 in the thickness direction after mounting. This clearance provides a safe cutting space for subsequent processes, prevents damage to the electrode 122 during cutting, has a high tolerance for cutting depth, and is conducive to improving cutting yield.

[0035] In this embodiment, at least two sandblasting processes are included. The first sandblasting forms the groove 111, and the second sandblasting is used to grind and correct the groove wall of the groove 111. The correction includes the correction of the groove wall inclination angle and the depth of the groove 111. The groove wall of the groove 111 includes a bottom wall and a side wall 1111. By grinding and correcting the bottom wall and the side wall 1111, the forming accuracy of the groove 111 can be improved, the shape and position deviation can be reduced, which is conducive to improving the alignment accuracy in the subsequent bonding process, and avoiding excessive alignment offset between the electrode 122 and the groove 111, thereby damaging the electrode 122 during cutting.

[0036] Please combine Figure 4 Optionally, during or after the second sandblasting process, a micro-channel drainage groove 113 can be formed on the sidewall 1111 of the groove 111. The micro-channel drainage groove 113 can drain the overflowed colloid, allowing the overflowed colloid in subsequent processes to flow along the drainage groove 113, preventing the overflowed glue 131 from contaminating the electrode 122. The drainage groove 113 adopts a micro-channel structure, which has a certain capillary effect on the overflowed glue 131, further improving the fluidity of the overflowed glue 131 flowing into the groove 111, improving the drainage and guiding properties, further preventing the overflowed glue 131 from contaminating the electrode 122, and improving the reliability of the electrode 122.

[0037] Please combine Figure 5 Optionally, a positioning mark portion 114 can also be formed in the sandblasting process, which serves as a positioning reference in the bonding process, improves the alignment accuracy in the subsequent bonding process, and thus improves the packaging yield. The positioning mark portion 114 can be formed in the first or second sandblasting process, or can be formed in the first sandblasting and the second sandblasting respectively. The shape, size, number and distribution position of the positioning mark portion 114 can be flexibly designed. In this embodiment, a corresponding positioning pattern can be designed on the mask, so that the positioning mark portion 114 can be formed in the process of forming the groove 111. The positioning mark portion 114 can be a pit or a column with a different depth from the groove 111. Of course, the mask with the positioning pattern and the mask for forming the groove 111 pattern can be designed on the same mask body, or can be designed on two masks respectively, and there is no specific limitation here.

[0038] Please combine Figure 6Optionally, after the groove 111 is formed, a glue groove 115 is formed on the surface of the mounting portion 112. The glue groove 115 can be an annular groove formed along the edge of each mounting portion 112, or can be a pit or a plurality of strip grooves or a mesh groove arranged on the surface of the entire mounting portion 112. The setting of the glue groove 115 has the functions of storing glue and blocking glue, further preventing the colloid from overflowing. The setting of the glue groove 115 increases the contact area between the mounting portion 112 and the colloid, which is beneficial to improving the bonding force and bonding reliability of the transparent cover plate 110 and the wafer 120.

[0039] Please combine Figure 7 Optionally, an overflow port 116 may be provided on the wall of the adhesive holding tank 115 to facilitate the overflowing adhesive 131 to flow out from the overflow port 116 and flow along the sidewall 1111 of the groove 111, further preventing the overflowing adhesive 131 from contaminating the electrode 122 on the wafer 120. The overflow port 116 is lower than the notch of the adhesive holding tank 115. In this way, the excess overflowing adhesive 131 flows out from the overflow port 116 and will not spread from the notch of the adhesive holding tank 115 to the wafer 120 and contaminate the electrode 122.

[0040] Step S3: Provide wafer 120. Figure 8 , wherein a plurality of light-emitting areas 121 are provided on the wafer 120 , an electrode 122 is provided on the periphery of the light-emitting area 121 , and a preset interval is provided between the electrode 122 and the light-emitting area 121 .

[0041] Step S4 , bonding the wafer 120 and the transparent cover plate 110 ; wherein the light emitting area 121 corresponds to the mounting portion 112 one by one and is pressed together.

[0042] Optional, please combine Figure 9 , a light-transmitting glue 130 is formed on the light-emitting area 121 and / or the mounting portion 112 of the wafer 120. The light-transmitting glue 130 can be preset only in the light-emitting area 121 of the wafer 120, or can be formed only on the mounting portion 112 of the light-transmitting cover plate 110, or the light-transmitting glue 130 can be formed respectively on the light-emitting area 121 of the wafer 120 and the mounting portion 112 of the light-transmitting cover plate 110. In this embodiment, the light-transmitting glue 130 is formed on the mounting portion 112 in advance. A layer of highly transparent bonding glue is applied to the surface of the mounting portion 112 by screen printing or rolling glue, and the thickness of the bonding glue is 1 to 10 um. By controlling the thickness of the light-transmitting glue 130, the overflow of the glue can be reduced.

[0043] Please combine Figure 10 and Figure 11, pressing wafer 120 and transparent cover plate 110 together. Wafer 120 is located at the top, and transparent cover plate 110 is located at the bottom. This effectively allows groove 111 to function as a glue container. Even if transparent glue 130 overflows, it will flow downward under the action of gravity, passing through the sidewalls 1111 of groove 111 to the bottom of the groove, without overflowing onto wafer 120 above and contaminating electrode 122.

[0044] It should be noted that in the bonding process, the positioning mark part 114 is used to first accurately align the wafer 120 and the transparent cover plate 110, and the alignment accuracy can be controlled within 20um. Then a pressing machine is used for permanent bonding. Among them, the pressing machine first pre-presses the transparent cover plate 110 at room temperature and pressure. The pre-pressing process can discharge most of the gas in the transparent glue 130. Due to the setting of the groove 111, the discharged gas can also be accommodated, reducing the residual gas in the transparent glue 130. It should be noted that if the gas cannot be discharged, the residual gas is likely to form bubbles in the colloid, resulting in the formation of voids at the junction of the transparent cover plate 110 and the wafer 120. Severe cases will also cause colloid stratification, affecting the packaging reliability and product luminous quality.

[0045] After pre-pressing, pressing is performed by increasing the temperature and applying pressure in a vacuum environment. The vacuum environment can further expel bubbles in the light-transmitting glue 130 and reduce the residual gas in the colloid. Temperature and pressure can ensure the uniformity of the light-transmitting glue 130 in the functional area of ​​the chip, that is, the light-emitting area 121, and can effectively improve the light-emitting quality. During the pressing process, if there is overflow of glue 131, the overflow of glue 131 will flow to the groove 111 of the light-transmitting cover plate 110 and will not contaminate the electrode 122. The groove 111 of the light-transmitting cover plate 110 will be cut and removed later, and the overflow of glue 131 in the groove 111 will not affect the yield and light-emitting quality of the final packaging structure.

[0046] Optionally, the pressing is performed under the conditions of a first temperature and a first pressure for a first preset time and maintained for a second preset time. The pressing is performed under the conditions of a second temperature and a second pressure for a third preset time and maintained for a fourth preset time. The second temperature is greater than the first temperature; and the second pressure is greater than the first pressure.

[0047] Specifically, the pressing method under vacuum environment is as follows: 1. Heat the upper and lower hot plates to 60-70°C respectively, with zero pressure, and maintain for 3 to 5 minutes; 2. Maintain the upper and lower hot plate temperatures at 60-70°C, apply a first pressure of 200-500 mbar, and maintain for 3 to 5 minutes; 3. Heat the upper and lower hot plates to about 80℃-90℃ respectively, apply a second pressure of 1000-1500mbar and maintain for 10 to 15 minutes; 4. Gradually cool down to room temperature (25°C), release the vacuum, and gradually reduce the pressure to zero, completing the pressing step under vacuum environment.

[0048] Please combine Figure 12 In step S5 , the transparent cover plate 110 is cut along the edge of the mounting portion 112 , the groove 111 structure is removed, and a wafer 120 with a transparent patch 117 is formed; the projection of the transparent patch 117 on the wafer 120 does not overlap with the electrode 122 .

[0049] The light-transmitting cover plate 110 can be cut by laser cutting, knife cutting, or the like. Optionally, a first cutting member 140 is used to cut from the surface of the light-transmitting cover plate 110 away from the wafer 120. The first cutting member 140 can use a cutter wheel to cut and remove the light-transmitting cover plate 110 above the electrode 122, exposing the electrode 122 on the wafer 120, making it easier to perform wire bonding on the electrode 122 in the subsequent process. It is understood that the depth of the groove 111 is greater than or equal to 5um, so that there is a sufficient safety distance between the cutting stop depth and the electrode 122, ensuring that the cutter wheel cutting will not damage the electrode 122 on the wafer 120.

[0050] Specifically, the design of the cutting path on the transparent cover plate 110 can be designed according to the cutting type and cutting width of the cutter wheel. For example, if the cutting width of the cutter is greater than the width of the bottom of the groove 111, the transparent cover plate 110 between two adjacent mounting parts 112 can be cut and removed at one time. If the cutting width of the cutter is greater than the width of the bottom of the groove 111, the transparent cover plate 110 between two adjacent mounting parts 112 can be cut and removed in two steps. After cutting, only the portion of the transparent cover plate 110 corresponding to the mounting part 112 is retained, that is, a single transparent patch 117. It is easy to understand that the projection of the transparent patch 117 on the wafer 120 can completely cover the light-emitting area 121. That is, the width or diameter of the transparent patch 117 is greater than or equal to the width or diameter of the light-emitting area 121. The edge of the projection of the transparent patch 117 on the wafer 120 falls between the electrode 122 and the light-emitting area 121, which provides sufficient operating space for the wire bonding operation of the electrode 122.

[0051] Step S6: cutting the wafer 120 into individual chips.

[0052] Please combine Figure 13 The entire wafer 120 is cut using the second cutting piece 150 , including but not limited to using a knife cutting, laser cutting or hidden cutting method, to form a single independent small chip.

[0053] Step S7: Mount the chip on the substrate 160. Figure 14A pad 161 is provided on the substrate 160. Each chip is mounted on the substrate 160. The electrodes 122 on the chip and the pad 161 on the substrate 160 are connected by metal wires 162 to achieve electrical connection between the chip and the substrate 160 to form a packaging structure.

[0054] An embodiment of the present invention also provides a packaging structure manufactured using the aforementioned wafer-level packaging method for an OLED chip. The packaging structure includes a chip, a light-transmitting patch 117, and a substrate 160. The chip is provided with a light-emitting region 121 and an electrode 122 spaced apart from the light-emitting region 121. Light-transmitting patch 117 is bonded to the light-emitting region 121 using a light-transmitting adhesive 130. Electrode 122 is electrically connected to substrate 160.

[0055] In summary, the wafer-level packaging method and packaging structure of the OLED chip provided by the embodiments of the present invention have the following beneficial effects, including: A transparent cover plate 110 of comparable size to the wafer 120 is used and bonded to the wafer 120 at one time. After bonding is completed, it is cut and separated into individual transparent patches 117. This full-process wafer-level packaging process replaces traditional single-chip packaging, greatly improving packaging efficiency and reducing costs. The wafer 120-level bonding process is used for pre-pressing first, and then heating and pressurizing in a vacuum environment for pressing. This can effectively reduce bubbles in the transparent glue 130, ensure the uniformity of the glue thickness after pressing, and improve the luminous quality and packaging yield. The wafer-level pressing method can effectively control the amount and thickness of the transparent glue 130, thereby improving the uniformity of pressing. The vacuum environment used in the process, the temperature and high pressure can effectively expel the colloidal bubbles, which can improve the luminous quality of the OLED from multiple aspects. Before the bonding process, a groove 111 is first formed on the transparent cover plate 110. During bonding, the overflowing transparent glue 130 can flow into the groove 111 to prevent the overflowing glue 131 from contaminating the electrode 122. And the bubbles in the colloid can also be discharged into the groove 111 to reduce residual gas. Subsequent cutting and removal of the groove 111 structure can release the residual gas in the groove 111 and expose the electrode 122, which is convenient for subsequent wiring operations. The wafer-level packaging method of the OLED chip provided in this embodiment is conducive to improving the packaging efficiency and packaging yield. Of course, in addition to being applicable to the wafer-level packaging of OLED chips, this method is also applicable to the packaging of other chips with similar structures.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. Any modifications, equivalent replacements, improvements, etc. made should be included in the scope of protection of the present invention.

Claims

1. A wafer-level packaging method for an OLED chip, characterized in that: include: A light-transmitting cover plate and a wafer are provided respectively; wherein the wafer is provided with a plurality of light-emitting areas, electrodes are provided on the periphery of the light-emitting areas, and a preset interval is provided between the electrodes and the light-emitting areas; A plurality of grooves are formed on one side of the light-transmitting cover plate, wherein the depth of the grooves is less than the thickness of the light-transmitting cover plate; and mounting portions are formed between the plurality of grooves; Bonding the wafer and the light-transmitting cover plate; wherein the light-emitting areas correspond to the mounting portions one by one and are pressed together; Cutting the transparent cover plate along the edge of the mounting portion to remove the groove structure, thereby forming a wafer with a transparent patch; the projection of the transparent patch on the wafer does not overlap with the electrode; The wafer is diced to form individual chips.

2. The wafer-level packaging method for OLED chips according to claim 1, wherein: The step of bonding the wafer and the light-transmitting cover plate includes: forming a light-transmitting adhesive on the light-emitting area of ​​the wafer and / or the mounting portion; The wafer and the light-transmitting cover plate are pressed together, wherein the wafer is on the upper side and the light-transmitting cover plate is on the lower side.

3. The wafer-level packaging method for OLED chips according to claim 2, wherein: The step of pressing the wafer and the light-transmitting cover plate together comprises: Pre-pressing the wafer and the light-transmitting cover plate at room temperature and pressure; The wafer and the light-transmitting cover plate are pressed together in a vacuum environment under heating and pressurizing conditions.

4. The wafer-level packaging method for OLED chips according to claim 3, wherein: The step of pressing the wafer and the light-transmitting cover plate together under vacuum conditions and heating and pressurizing conditions includes: Pressing for a first preset time under the conditions of a first temperature and a first pressure, and maintaining for a second preset time; pressing at the second temperature and the second pressure for a third preset time, and maintaining the pressing for a fourth preset time; The second temperature is greater than the first temperature; the second pressure is greater than the first pressure.

5. The wafer-level packaging method for OLED chips according to claim 1, wherein: In the step of forming a plurality of grooves on one side of the light-transmitting cover plate: forming the grooves by sandblasting or etching; If sandblasting is used, it includes at least two sandblasting processes; wherein, the first sandblasting forms the groove, and the second sandblasting grinds and corrects the groove wall of the groove; wherein the correction includes correction of the groove wall inclination angle and the groove depth.

6. The wafer-level packaging method for OLED chips according to claim 1, wherein: After the step of forming a plurality of grooves on one side of the light-transmitting cover plate, the method further includes: A drainage groove is formed on the side wall of the groove.

7. The wafer-level packaging method for OLED chips according to claim 2, wherein: The step of forming a light-transmitting adhesive on the light-emitting area of ​​the wafer and / or the mounting portion includes: forming a glue containing groove on the mounting portion; A light-transmitting adhesive is formed on the mounting portion.

8. The wafer-level packaging method for OLED chips according to claim 7, wherein: After the step of forming a glue containing groove on the mounting portion, the method further includes: An overflow port is provided on the wall of the above-mentioned glue containing groove; the overflow port is connected with the glue containing groove and the groove.

9. The wafer-level packaging method for an OLED chip according to any one of claims 1 to 8, characterized in that: The step of forming a plurality of grooves on one side of the light-transmitting cover plate further includes: A positioning marking portion is formed on one side of the light-transmitting cover plate having the groove.

10. A packaging structure, characterized in that: The OLED chip is manufactured using the wafer-level packaging method according to any one of claims 1 to 9.

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