Display device and LED chip packaging body

Abstract

The utility model discloses a display device and a flip LED chip packaging body, the display device comprises a substrate (1) and a substrate electrode (2), the substrate electrode (2) comprises an insertion portion, a first protrusion portion and a second protrusion portion; wherein the first protruding part and the second protruding part are connected to the two ends of the inserting part respectively, the inserting part penetrates through the base plate (1), the first protruding part is located on the upper surface of the base plate (1), and the second protruding part is located on the lower surface of the base plate (1); and the first convex part is provided with a rough upper surface. According to the utility model, the surface of the existing smooth substrate electrode is roughened, after the substrate electrode is roughened, the contact area of the solder paste and the substrate electrode is increased, the heat dissipation effect is improved due to the increase of the contact area, and meanwhile, the chip die bonding capability and the die bonding yield are also improved through the increase of the contact area.

Description

Technical Field

[0001] The utility model relates to the technical field of LED production, in particular to a display device and an LED chip package. Background Art

[0002] LED can be used as LCD backlight for large-size display screens, smart phones, automotive panels, notebooks and other products, and can also be used as RGB three-color LED chips to achieve self-luminous display; with the miniaturization of LED, Micro LED products have the characteristics of extremely small pitch, high contrast and high refresh rate, and can be used in smart watches, AR, VR and other smart wearable devices for close viewing. At present, Mini LED backlight applications have entered the mass production stage. The solution of mass transfer technology in the future will surely greatly promote the commercialization of Micro LED, and Micro LED is ready to go.

[0003] In LED chip packaging, the LED display (mainly small pitch) industry has developed to date. In addition to the traditional direct insertion process, a variety of packaging processes including SMD, COB, IMD, etc. have been formed. COB, that is, chip on board packaging technology (Chip on Board), is different from SMD (abbreviation of Surface Mounted Devices, meaning surface mount devices) to solder lamp beads to PCB. The COB process first covers the silicon chip placement point on the substrate surface with thermal conductive epoxy resin (epoxy resin doped with silver particles), and then adheres the LED chip to the interconnection substrate with conductive or non-conductive glue through adhesive or solder, and finally realizes electrical interconnection between the chip and the PCB board through wire (gold wire) bonding. The LED wafer is fixed on the front surface of the display substrate, and the film is attached to the front surface of the display substrate. The LED wafer is an ordinary red, green, and blue LED light-emitting chip to achieve integrated packaging. However, due to the high degree of integration, heat dissipation is still one of the main problems facing COB packaging.

[0004] The patent application with application number 201110152295.0 discloses a method for manufacturing a light-emitting diode packaging structure, and discloses forming a rough structure on the surface of a substrate, thereby reducing the contact area between the substrate and the metal layer to separate the substrate and the metal layer, so that the light-emitting diode packaging structure after packaging is free of substrate, thereby making the light-emitting diode packaging structure thinner and lighter; and because the light-emitting diode chip is directly fixed on the metal layer, the heat generated by the light-emitting diode chip during operation can be directly dissipated to the surrounding air through the metal layer, and the metal layer is directly exposed outside the light-emitting diode packaging structure because there is no substrate to block it, so the heat dissipation effect is better and the service life of the light-emitting diode packaging structure is increased. However, for COB packaging, due to its structural characteristics, it is impossible to improve the heat dissipation effect by removing the substrate. Therefore, how to improve the heat dissipation problem of LED chips in COB packaging has become a technical problem that needs to be solved urgently by those skilled in the art.

[0005] Based on this, the existing technology still needs to be improved. Utility Model Content

[0006] In order to solve the above technical problems, the embodiments of the present invention provide a display device and an LED chip package to solve the heat dissipation problem existing in the COB package of the prior art.

[0007] In order to solve the above technical problems, on the one hand, some embodiments of the utility model disclose a flip-chip LED chip package, including a substrate and a substrate electrode, the substrate electrode including an insertion portion, a first protrusion portion and a second protrusion portion, wherein the first protrusion portion and the second protrusion portion are respectively connected to two ends of the insertion portion, the insertion portion passes through the substrate, the first protrusion portion protrudes from the upper surface of the substrate, and the second protrusion portion protrudes from the lower surface of the substrate;

[0008] Furthermore, the first protrusion has a rough upper surface.

[0009] Some embodiments further include a flip chip and solder paste, wherein the chip electrode of the flip chip is connected to the upper surface of the first protrusion of the substrate electrode through the solder paste.

[0010] In some embodiments, the second protrusion has a rough lower surface.

[0011] In some embodiments, the substrate has a rough upper surface;

[0012] The cross-sectional area of ​​the first protrusion is greater than that of the insertion portion, so that the first protrusion has a first extension portion extending outward from the top of the insertion portion, and the first extension portion is in contact with and connected to the rough upper surface of the substrate.

[0013] In some embodiments, the first extension has a rough lower surface.

[0014] In some embodiments, the substrate has a rough lower surface;

[0015] The cross-sectional area of ​​the second protrusion is greater than that of the insertion portion, so that the second protrusion has a second extension portion extending outward from the bottom end of the insertion portion, and the second extension portion is in contact with the rough lower surface of the substrate.

[0016] In some embodiments, the second extension has a rough upper surface.

[0017] In some embodiments, a packaging colloid is further included, and the packaging colloid packages the flip chip on the upper surface of the substrate.

[0018] In some embodiments, the upper surface of the first protrusion and the lower surface of the second protrusion are in the shape of triangular pyramidal protrusions or pits.

[0019] On the other hand, an embodiment of the present utility model further discloses a display device, which includes the above-mentioned LED chip package.

[0020] By adopting the above technical solution, the utility model has at least the following beneficial effects:

[0021] The utility model provides a display device and LED chip package, which roughens the surface of the existing smooth substrate electrode. After the substrate electrode is roughened, the contact area between the solder paste and the substrate electrode is increased, and the heat dissipation effect is increased. At the same time, the increase in the contact area also improves the chip bonding ability and the bonding yield rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A schematic diagram of the structure of an LED chip package disclosed in the prior art of the utility model;

[0024] Figure 2 A schematic diagram of the structure of an LED chip package disclosed in some embodiments of the utility model;

[0025] Figure 3 The present invention is a schematic structural diagram of an LED chip package disclosed in some embodiments of the present invention.

[0026] Description of reference numerals:

[0027] 1. Substrate; 2. Substrate electrode; 3. Solder paste; 4. Chip electrode; 5. Flip chip; 6. Packaging colloid. DETAILED DESCRIPTION

[0028] The following is a further detailed description of the embodiments of the present disclosure in conjunction with the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present disclosure, but cannot be used to limit the scope of the present disclosure. The present disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

[0029] The present disclosure provides these embodiments to make the present disclosure thorough and complete, and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the parts and steps, the composition of the materials, the numerical expressions and the numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary, and not as limiting.

[0030] It should be noted that, in the description of the present disclosure, unless otherwise specified, the meaning of "multiple" is greater than or equal to two; the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present disclosure. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0031] In addition, the words "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different parts. "Vertical" does not mean vertical in the strict sense, but is within the tolerance range. "Parallel" does not mean parallel in the strict sense, but is within the tolerance range. "Include" or "comprising" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements.

[0032] It should also be noted that in the description of the present disclosure, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to the specific circumstances. When a specific device is described as being located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device.

[0033] All terms used in the present disclosure have the same meanings as those understood by those of ordinary skill in the art to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, for example, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined as such herein.

[0034] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0035] like Figure 1 As shown, in the flip-chip LED chip package of the prior art, during conventional COB packaging, the flip chip 5 is welded to the solder paste 3 and the substrate electrode 2 on the substrate 1 through the electrode to form a current loop, and heat is also dissipated through the substrate electrode 2 and the substrate 1. However, since the traditional substrate electrode 2 is a platform structure, the contact area with the solder paste 3 is the area of ​​the substrate electrode 2, resulting in a small contact area and poor heat dissipation capability. In addition, the flat contact connection method also has a weak solid crystal capability, resulting in a low solid crystal yield.

[0036] In order to improve the heat dissipation capacity of the COB packaged flip-chip LED chip package and improve the die bonding yield, such as Figure 2 As shown, some embodiments of the utility model disclose a flip-chip LED chip package, including a substrate 1 and a substrate electrode 2, wherein the substrate electrode 2 includes an inserting portion, a first protruding portion, and a second protruding portion, that is, the cross-sections of the first protruding portion, the inserting portion, and the second protruding portion form an I-shaped structure, wherein the first protruding portion and the second protruding portion are respectively connected to the two ends of the inserting portion, the inserting portion passes through the substrate 1, the first protruding portion is located on the upper surface of the substrate 1, and the second protruding portion is located on the lower surface of the substrate 1; and the first protruding portion has a rough upper surface. During preparation, a flip chip 5 and solder paste 3 are also required, and the chip electrode 4 of the flip chip 5 is generally connected to the upper surface of the first protruding portion of the substrate electrode 2 through the solder paste 3, thereby realizing the electrical connection between the flip chip 5 and the substrate electrode 2.

[0037] In this embodiment, the upper surface of the first protrusion is roughened, that is, the surface of the existing smooth substrate electrode 2 is roughened. After the substrate electrode 2 is roughened, the contact area between the solder paste 3 and the substrate electrode 2 is increased, and the increased contact area increases the heat dissipation effect. At the same time, the increase in the contact area also improves the chip bonding ability and effectively improves the bonding yield. The display device manufactured by the display device has an effectively improved service life due to the increase in heat dissipation and bonding abilities.

[0038] The LED chip package disclosed in some embodiments of the utility model, on the basis of the above embodiments, in order to further improve the heat dissipation capacity, the first protrusion has a rough upper surface, and on the basis of increasing its contact area with the solder paste 3, the second protrusion also has a rough lower surface. The rough surface can be in the shape of a triangular pyramidal protrusion or a pit. During preparation, the smooth substrate electrode 2 part can be roughened by a mechanical roughening method or a chemical roughening method. The mechanical roughening method can be sandblasting, tumbling, sandpaper polishing and other methods, and the chemical roughening method can be carried out by fluoride or alkaline texture etching. However, since the area of ​​the substrate electrode 2 is small, this scheme generally recommends the use of a chemical roughening method, using potassium hydroxide corrosion, and the corrosion time is determined by the target roughening degree. After the substrate electrode 2 is roughened, the contact area between the solder paste 3 and the substrate electrode 2 is increased, and the increase in the contact area can effectively increase the heat dissipation. At the same time, by increasing the contact area, the chip solid crystal ability is also improved, and the solid crystal yield rate is improved.

[0039] like Figure 3 As shown, the LED chip package disclosed in some embodiments of the utility model, on the basis of setting the upper surface of the first protrusion and the lower surface of the second protrusion to be rough, in order to further improve the heat dissipation capacity, the substrate 1 can be further provided with a rough upper surface; the cross-sectional area of ​​the first protrusion is larger than the cross-sectional area of ​​the insertion part, so that the first protrusion has a first extension extending outward from the top of the insertion part, and the first extension is in contact with the rough upper surface of the substrate 1. In this case, the first extension can generally also have a rough lower surface. Similarly, the lower surface of the substrate 1 can also be set to be rough, the cross-sectional area of ​​the second protrusion is larger than the cross-sectional area of ​​the insertion part, so that the second protrusion has a second extension extending outward from the bottom of the insertion part, and the second extension is in contact with the rough lower surface of the substrate 1, and the second extension can also have a rough upper surface. The contact area of ​​the connection is increased by the rough contact connection between the substrate 1 and the substrate electrode 2, and the solid crystal substrate 1 is roughened. The purpose of this step of roughening is to increase the contact area between the solid crystal substrate 1 and the packaging colloid 6. Similarly, the loss of heat generated by the chip in the solid crystal colloid is accelerated, and the heat dissipation is accelerated. At the same time, the adhesion between the packaging glue and the substrate 1 is also increased, the ability of the lamp bead to resist water vapor and the like after packaging is improved, and the aging ability is improved.

[0040] Some embodiments of the utility model disclose a small-volume LED chip package for assembly into a display device, wherein the Micro LED has extremely small pitch, high contrast and high refresh rate, and is suitable for smart wearable devices such as smart watches, AR, VR, etc. that are viewed at close range. It includes a packaging colloid 6, a substrate 1, a substrate electrode 2, a flip chip 5 and solder paste 3, wherein the substrate electrode 2 includes an insertion portion, a first protrusion and a second protrusion, wherein the first protrusion and the second protrusion are respectively connected to the two ends of the insertion portion, the insertion portion passes through the substrate 1, the first protrusion is located on the upper surface of the substrate 1, and the second protrusion is located on the lower surface of the substrate 1; the chip electrode 4 of the flip chip 5 is connected to the upper surface of the first protrusion of the substrate electrode 2 through the solder paste 3.

[0041] Among them, the upper surface of the first protrusion and the lower surface thereof in contact with the substrate 1 are both roughened by chemical means (potassium hydroxide corrosion), and the lower surface of the second protrusion and the upper surface thereof in contact with the substrate 1 are also roughened by chemical means; at the same time, the upper and lower surfaces of the substrate 1 are roughened by mechanical roughening methods (sandblasting or rolling, etc.). Finally, a rough contact connection is formed between the substrate electrode 2 and the substrate 1, and a rough contact connection is formed between the substrate electrode 2 and the solder paste 3. As a result, the contact area between the solder paste 3 and the substrate electrode 2 is increased, and the contact area between the solid crystal substrate 1 (substrate 1) and the packaging colloid 6 is increased. The contact area is increased to increase heat dissipation. At the same time, by increasing the contact area, the chip solid crystal ability is also improved, the solid crystal yield is improved, the adhesion between the packaging colloid 6 and the substrate 1 is increased, the ability of the lamp bead to resist water vapor after packaging is improved, and the aging ability is improved.

[0042] So far, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

[0043] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present disclosure. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict.

Claims

1. A flip-chip LED chip package, characterized in that: It comprises a substrate (1) and a substrate electrode (2), wherein the substrate electrode (2) comprises an insertion portion, a first protruding portion and a second protruding portion; The first protrusion and the second protrusion are respectively connected to two ends of the insertion part, the insertion part passes through the substrate (1), the first protrusion protrudes from the upper surface of the substrate (1), and the second protrusion protrudes from the lower surface of the substrate (1); Furthermore, the first protrusion has a rough upper surface.

2. The LED chip package according to claim 1, characterized in that: It also comprises a flip chip (5) and solder paste (3), wherein the chip electrode (4) of the flip chip (5) is connected to the upper surface of the first protruding portion of the substrate electrode (2) through the solder paste (3).

3. The LED chip package according to claim 2, characterized in that: The second protrusion has a rough lower surface.

4. The LED chip package according to claim 2, characterized in that: The substrate (1) has a rough upper surface; The cross-sectional area of ​​the first protrusion is greater than the cross-sectional area of ​​the insertion portion, so that the first protrusion has a first extension portion extending outward from the top end of the insertion portion, and the first extension portion is in contact with and connected to the rough upper surface of the substrate (1).

5. The LED chip package according to claim 4, characterized in that: The first extension portion has a rough lower surface.

6. The LED chip package according to claim 2, characterized in that: The substrate (1) has a rough lower surface; The cross-sectional area of ​​the second protrusion is greater than the cross-sectional area of ​​the insertion portion, so that the second protrusion has a second extension portion extending outward from the bottom end of the insertion portion, and the second extension portion is in contact with and connected to the rough lower surface of the substrate (1).

7. The LED chip package according to claim 6, characterized in that: The second extension portion has a rough upper surface.

8. The LED chip package according to claim 2, characterized in that: It also comprises a packaging colloid (6), wherein the packaging colloid (6) packages the flip chip (5) on the upper surface of the substrate (1).

9. The LED chip package according to claim 3, characterized in that: The upper surface of the first protrusion and the lower surface of the second protrusion are in the shape of triangular pyramidal protrusions or pits.

10. A display device, characterized in that: The LED chip package comprises the LED chip package according to any one of claims 1 to 9.

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