Light-emitting unit and light-emitting device

Abstract

The utility model discloses a light-emitting unit and a light-emitting device. The light-emitting unit comprises a light-emitting chip, the light-emitting chip is provided with a top surface and a bottom surface which are opposite in the thickness direction and an annular side surface surrounding the top surface and the bottom surface, the bottom surface of the light-emitting chip is provided with a connecting pad, and the top surface of the light-emitting chip is provided with a wire bonding contact; and the optical colloid surrounds the annular side surface of the light-emitting chip, and the top surface and the bottom surface of the light-emitting chip are exposed out of the optical colloid.

Description

TECHNICAL FIELD

[0001] The utility model relates to a unit, especially a light-emitting unit and a light-emitting device. BACKGROUND

[0002] At present, the LED industry introduces various light-emitting devices in the form of chip-scale package (CSP). Among them, the existing CSP mostly uses flip-chip and encapsulates five surfaces of the flip-chip. However, the vertical chip has a more optimal light extraction efficiency than the flip-chip, but the vertical chip is limited by the wire bonding position, which leads to the inability to be applied to the existing CSP process of flip-chip. In other words, the industry currently lacks a solution to make the vertical chip into CSP form and flexibly apply it to the light-emitting device.

[0003] Therefore, the present inventors believe that the above-mentioned defects can be improved, and after careful research and application of scientific principles, finally propose the present utility model, which is reasonably designed and effectively improves the above-mentioned defects. SUMMARY

[0004] The utility model solves the technical problem in the prior art and provides a light-emitting unit and a light-emitting device.

[0005] The utility model discloses a light-emitting unit, comprising: a light-emitting chip, having a top surface and a bottom surface opposite in a thickness direction and a ring side surface surrounding the top surface and the bottom surface, the bottom surface of the light-emitting chip has a connection pad, and the top surface of the light-emitting chip has a wire bonding point; and an optical glue surrounds the ring side surface of the light-emitting chip and exposes the top surface and the bottom surface of the light-emitting chip outside the optical glue.

[0006] Preferably, the optical glue generates a notch at the position adjacent to the connection pad.

[0007] Preferably, the cross section of the notch along the thickness direction is in two arc shapes.

[0008] Preferably, the light-emitting chip has a first minimum thickness along the thickness direction, the optical glue has a second minimum thickness along the thickness direction, and the first minimum thickness is greater than the second minimum thickness.

[0009] Preferably, the second minimum thickness is between 75% and 85% of the first minimum thickness.

[0010] Preferably, the optical glue contains a plurality of functional particles.

[0011] Preferably, the plurality of functional particles comprises at least one of light-reflecting particles, dyed particles, light-diffusing particles, light-absorbing particles, and fluorescent particles.

[0012] Preferably, the top surface of the light-emitting chip has a first height position; the optical gel comprises a mesa having a second height position, which is lower than the first height position, so that the portion of the ring side surface adjacent to the top surface is exposed outside the optical gel.

[0013] Preferably, there is a height difference between the first height position and the second height position, which is less than 50% of the thickness of the light-emitting chip in the thickness direction.

[0014] Preferably, the height difference is between 10 and 15 microns.

[0015] Preferably, the width of the mesa is not less than 30 microns.

[0016] The utility model embodiment further discloses a light-emitting device, comprising the light-emitting unit as described above, the light-emitting device comprises: a substrate comprising a first circuit and a second circuit, and the light-emitting unit is arranged on the substrate, and a packaging gel is arranged on the substrate and covers the light-emitting unit, wherein the light-emitting chip is fixed to the first circuit through the connecting pad, the wire bonding point is connected to the second circuit through a conductive wire of the light-emitting device, and the conductive wire is not covered by the optical gel.

[0017] Preferably, the top surface of the light-emitting chip has a first height position relative to the substrate; the optical gel comprises a mesa away from the substrate, and the mesa has a second height position relative to the substrate, which is lower than the first height position, so that the portion of the ring side surface adjacent to the top surface is exposed outside the optical gel.

[0018] Preferably, the light-emitting device further comprises a fence surrounding the packaging gel.

[0019] Preferably, the missing slot is filled with the packaging gel.

[0020] In summary, the light-emitting unit and the light-emitting device disclosed in the utility model embodiment can improve yield and light emission performance through the design that "the optical gel surrounds the ring side surface of the light-emitting chip, and the top surface and the bottom surface of the light-emitting chip are exposed outside the optical gel".

[0021] For further understanding the features and technical contents of the present application, please refer to the following detailed description and drawings of the present application. However, the description and drawings are only used to illustrate the present application, and do not limit the protection scope of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 A plane schematic view of a light emitting unit of the present application.

[0023] Figure 2 A plane schematic view of a light emitting device of the present application.

[0024] Figure 3 A process schematic view of a manufacturing method of a light emitting unit of the present application.

[0025] Figure 4 A plane schematic view of a light emitting chip to be arranged on a heat conducting layer of the present application.

[0026] Figure 5 A plane schematic view of a light emitting chip partially immersed in a heat conducting layer of the present application.

[0027] Figure 6 A plane schematic view of an optical glue filled between light emitting chips of the present application.

[0028] Figure 7 A plane schematic view of an optical glue being cut of the present application.

[0029] Figure 8 A step process schematic view of a manufacturing method of a light emitting device of the present application.

[0030] Figure 9 A plane schematic view of an unprocessed substrate of the present application.

[0031] Figure 10 A plane schematic view of a light emitting unit arranged on a substrate of the present application.

[0032] Figure 11 A plane schematic view of a packaging glue covering a light emitting unit of the present application.

[0033] Figure 12 A plane schematic view of a packaging glue and a part of a substrate being cut of the present application.

[0034] Figure 13 A plane schematic view of a packaging glue being covered by an opaque glue of the present application.

[0035] Figure 14 A plane schematic view of an opaque glue being processed of the present application.

[0036] Figure 15 FIG. 8 is a plan view of the light-emitting device according to another embodiment of the present application.

[0037] Figure 16 FIG. 8 is a plan view of the light-emitting device according to another embodiment of the present application.

[0038] Figure 17 FIG. 8 is a plan view of the light-emitting device according to another embodiment of the present application. DETAILED DESCRIPTION

[0039] The following is a specific embodiment to illustrate the embodiments disclosed by the present application, and those skilled in the art can understand the advantages and effects of the present application from the disclosure. The present application can be implemented or applied by other different embodiments, and each detail in the specification can be modified and changed based on different viewpoints and applications without departing from the concept of the present application. In addition, the drawings of the present application are only simple schematic illustrations, not actual size depictions, and prior notice is given. The following embodiments will further illustrate the related technical content of the present application, but the disclosed content is not intended to limit the protection scope of the present application.

[0040] It should be understood that although the terms "first", "second", "third" and the like can be used herein to describe various components or signals, these components or signals should not be limited by these terms. These terms are mainly used to distinguish one component from another component, or one signal from another signal. In addition, the term "or" used herein can include any one or more combinations of the associated listed items. Furthermore, the term "electrically coupled" used herein means one of "indirect electrical connection" and "direct electrical connection".

[0041] Referring to Figure 1 The present application provides a light-emitting unit 2, which includes a light-emitting chip 21 and an optical adhesive 22. The structure of each component of the light-emitting unit 2 will be introduced below, and the connection relationship between each component of the light-emitting unit 2 will be explained in time.

[0042] In detail, the light-emitting chip 21 has a thickness direction D1, and a top surface M1 opposite to the thickness direction D1, a bottom surface M2, and a ring side surface M3 surrounding the top surface M1 and the bottom surface M2. The bottom surface M2 of the light-emitting chip 21 has a connection pad C1, and the top surface M1 of the light-emitting chip 21 has a wire bonding point C2.

[0043] Through the above structure, the light emitting chip 21 can be die-bonded on one line (for example, the first line 12 of the substrate 1 in the following Figure 2 ) of a substrate through the connection pad C1, and the wire bonding pad C2 can be bonded to another line (for example, the second line 13 of the substrate 1 in the following Figure 2 ) of the substrate through a conductive wire, so that the light emitting chip 21 can be electrically coupled to the substrate 1.

[0044] Reference Figure 1 As shown in the figure, the optical adhesive 22 surrounds the ring side surface M3 of the light emitting chip 21, so that the top surface M1 and the bottom surface M2 of the light emitting chip 21 are exposed outside the optical adhesive 22. In other words, the light emitting surface (i.e., the top surface M1) of the light emitting chip 21 is not covered by the optical adhesive 22, so as not to affect the light emitting amount.

[0045] It is worth noting that the optical adhesive 22 in the present embodiment also includes a plurality of functional particles FP, and the plurality of functional particles FP can have at least one of light reflecting particles, light absorbing particles, dyed particles, light diffusing particles, and fluorescent particles. In an embodiment, the plurality of functional particles FP are taken as light reflecting particles, the light emitting efficiency of the light emitting unit 2 in the embodiment can be effectively improved, and the light emitting angle can be effectively controlled.

[0046] Optionally, the optical adhesive 22 generates a groove GV adjacent to the connection pad C1. As shown in the following Figure 2 , the groove GV can be used to accommodate the excess die-bonding material FM, so as to increase the chip-to-substrate adhesion. At the same time, the groove GV reduces the phenomenon that the die-bonding material FM extends to the side surface of the optical adhesive 22, thereby affecting the appearance and optical effect (such as reflection or light diffusion effect) of the product. At the same time, the part of the groove GV not filled with the die-bonding material FM can also be filled with a precursor of a packaging adhesive (for example, the packaging adhesive 3 in the following Figure 2 ), so that the cured packaging adhesive can fill the groove GV and generate a geometric match with the optical adhesive. In this way, the connection reliability between the light emitting unit 2 and the packaging adhesive can be effectively improved.

[0047] Reference Figure 1 As shown in the figure, in subsequent applications in terminal products (for example, the light emitting device 100 in the following Figure 2 ), in order to ensure that the wire bonding pad C2 on the top surface of the light emitting chip 21 is exposed to the optical adhesive 22, the cross section of the light emitting unit 2 along the thickness direction D1 can be optionally designed as a stepped shape with high middle and low sides, so that the light emitting chip 21 surrounded by the optical adhesive 22 is more protruding than the optical adhesive 22.

[0048] Specifically, the top surface Ml of the light emitting chip 21 has a first height position (relative to the substrate 1), and the optical adhesive 22 has a mesa M4 (away from the substrate 1) with a second height position (relative to the substrate 1). The second height position is lower than the first height position, so that the portion of the ring side surface M3 adjacent to the top surface Ml is exposed outside the optical adhesive 22. In this way, the optical adhesive 22 can avoid covering the wire bonding pads C2 and the top surface Ml, thereby affecting the wire bonding space and the light emitting effect.

[0049] Preferably, a height difference HD between the first height position and the second height position is preferably less than 50% of the thickness of the light emitting chip 21 along the thickness direction Dl (i.e., the first minimum thickness T21). Alternatively, the height difference is between 10 to 15 microns.

[0050] In another aspect, the light emitting chip 21 has a first minimum thickness T21 along the thickness direction Dl, and the optical adhesive 22 has a second minimum thickness T22 along the thickness direction Dl, and the first minimum thickness T21 is greater than the second minimum thickness T22.

[0051] In a preferred embodiment, the second minimum thickness T22 can be between 75% to 85% of the first minimum thickness T21 (i.e., the height difference is between 15% to 25% of the thickness of the light emitting chip 21), to provide a more complete optical effect (e.g., reflection effect), while avoiding the optical adhesive 22 from escaping to the wire bonding pads C2. In addition, the width of the mesa M4 of the optical adhesive 22 is preferably not less than 30 microns, to ensure that the width of the optical adhesive 22 can provide an ideal optical effect (e.g., reflection effect).

[0052] The above is the structure of the light emitting unit 2 of the present application, but in order to better understand the light emitting unit 2 of the present application, the manufacturing process of the light emitting unit 2 in one embodiment is described below, and the manufacturing method of the light emitting unit 2 includes steps S101-S109 (as shown in Figure 3

[0053] [Manufacturing method of the light emitting unit 2]

[0054] Steps S101-S105 are shown in Figure 4 and Figure 5

[0055] Step S101: Apply a buffer layer 220 (e.g., buffer tape) with a deformation margin on a carrier 210 (e.g., steel plate).

[0056] ​​Step S103: Obtain multiple light-emitting chips 21, and the top surface M1 and bottom surface M2 of the light-emitting chip 21 respectively have a wire bonding contact C2 and a connecting pad C1.

[0057] Step S105: Multiple light-emitting chips 21 are disposed on the buffer layer 220 with the top surface M1, and each wire bonding point C2 and part of the light-emitting chip 21 are submerged in the buffer layer 220 through the deformation margin.

[0058] Step S107: Cooperation Figure 6 As shown, a liquid optical colloid 22 precursor is poured onto the buffer layer 220 and cured, so that the optical colloid 22 is located between the plurality of light-emitting chips 21. The top surface of the optical colloid 22 is lower than the surface of the plurality of light-emitting chips 21 away from the buffer layer 220, and the top surface forms an arc surface between any two adjacent light-emitting chips 21.

[0059] Step S109: Cooperation Figure 7 As shown, the cured optical colloid 22 is cut and separated, so that each light-emitting chip 21 is separated from the buffer layer 220 and has the optical colloid 22, to form a light-emitting unit 2 (e.g., Figure 1 (As shown). That is, the top surface M1 and the bottom surface M2 of the light-emitting chip 21 are exposed, and the annular side surface M3 of the light-emitting chip 21 is surrounded by the optical colloid 22.

[0060] Next, the following description uses the light-emitting device 100 provided by this utility model as an example. (In conjunction with...) Figure 2 As shown, the light-emitting device 100 includes a substrate 1, a light-emitting unit 2 disposed on the substrate 1, an encapsulating colloid 3 disposed on the substrate 1 and covering the light-emitting unit 2, and a conductive wire 4 connecting the substrate 1 and the light-emitting unit 2.

[0061] Specifically, in this embodiment, the substrate 1 can be a printed circuit board, and the substrate 1 includes a body 11, and a first line 12 and a second line 13 disposed on the body 11. The body 11 is a plate-shaped insulating material, and the body 11 has two wide sides and a plurality of narrow sides connecting the two wide sides. Furthermore, in this embodiment, the first line 12 and the second line 13 may each have pads and conductive posts, but this invention is not limited thereto.

[0062] Re-reference Figure 1 and Figure 2As shown, the light emitting unit 2 can be electrically coupled to the substrate 1 through the first circuit 12 and the second circuit 13. Specifically, the light emitting chip 21 is die-bonded to the first circuit 12 through the connection pad C1, and the wire-bonding pad C2 is bonded to the second circuit 13 through the conductive wire 4, so that the light emitting chip 21 is electrically coupled to the substrate 1. The encapsulation glue 3 is disposed on the substrate 1 and covers the light emitting unit 2 and the conductive wire 4, thereby protecting the light emitting unit 2 and the conductive wire 4.

[0063] The precursor of the encapsulation glue 3 can be filled into the groove GV before curing, and the optical glue 22 can also be fixed on the substrate 1 by the cured encapsulation glue 3. In addition, the conductive wire 4 is only covered by the encapsulation glue 3 but not covered by the optical glue 22, so that the conductive wire 4 only bears the single stress of the encapsulation glue 3, thereby avoiding the situation that the conductive wire 4 is pulled and damaged.

[0064] In practice, the encapsulation glue 3 can contain fluorescent particles or light diffusion particles, and the composition of the encapsulation glue 3 is different from that of the optical glue 22. In other words, the conductive wire 4 is not covered by two materials.

[0065] Of course, the composition of the optical glue 22 and the composition of the encapsulation glue 3 can also be the same as required, which can be, for example, epoxy-based resin or silicon-based resin.

[0066] It should be additionally noted that, as shown in Figure 16 In practice, the light emitting device 100' can be provided with a wall 5 on the substrate 1 as required. Optionally, the wall 5 can have reflectivity or light absorption. In an embodiment, the wall 5 surrounds and contacts the encapsulation glue 3, and the light emitting unit 2 is located on the inner side of the wall 5.

[0067] The above is the structure of the light emitting device 100, 100' of the present application, but in order to better understand the light emitting device 100 of the present application, the manufacturing process of the light emitting device 100' with the wall 5 in one embodiment is introduced as follows. The manufacturing method of the light emitting device 100' includes steps S201-S213 (as shown in Figure 8

[0068] [Manufacturing method of the light emitting device 100']

[0069] Steps S201-S203 are shown in Figure 9 and Figure 10

[0070] Step S201: as shown in Figure 9 and​​Figure 10 As shown, the connecting pads C1 of the light emitting unit 2 are die-bonded on the substrate 1 by using a conductive die-bonding material FM, and a first circuit 12 of the substrate 1 is electrically coupled, so that the bottom surface M2 of the light emitting chip 21 faces the substrate 1.

[0071] Step S203: connecting a second circuit 13 of the substrate 1 and the wire-bonding pads of the light emitting chip by using a conductive wire 4.

[0072] Step S205: cooperating Figure 11 As shown, a packaging glue 3 precursor in liquid state is poured and solidified. The packaging glue 3 after solidification covers the light emitting chip 21, the optical glue 22 and the conductive wire 4.

[0073] Step S207: cooperating Figure 12 As shown, the substrate 1 and the solidified packaging glue 3 are cut to generate a primary product. If the product does not need a wall 5, it can be completely cut off. If the product needs a wall 5, a semi-blind cut is performed and subsequent steps are performed, for example Figure 12 As shown, the cutting depth penetrates the packaging glue 3 and cuts part of the substrate 1.

[0074] Step S209: cooperating Figure 13 As shown, the packaging glue 3 on the primary product is covered by a precursor of the wall 5 and solidified.

[0075] Step S211: cooperating Figure 14 As shown, the solidified precursor is processed (for example, polished) so that the side of the packaging glue 3 away from the substrate 1 is not covered by the solidified material.

[0076] Step S213: cooperating Figure 15 As shown, the solidified material (and the substrate) is cut to generate a light emitting device 100' and the solidified material serves as a wall 5 (for example, a reflective wall) of the light emitting device 100'.

[0077] From the above, it can be known that the light emitting unit 2 in the vertical chip CSP form not only has good yield and light emitting performance, but also has more flexible configuration when applied to the light emitting device. For example, as shown in Figure 17 As shown, the light emitting device 100" in the vertical chip CSP form has an optical glue around each vertical chip, which can control the optical properties (such as light emitting angle, etc.) respectively, and multiple light emitting units 2 can be freely matched, and different colored CSPs can be selected for packaging in a single light emitting device, which has high degree of freedom and simplifies the process of the light emitting device, which cannot be realized by the existing vertical chip process.

[0078] [Technical effects of the utility model embodiment]

[0079] In summary, the light emitting unit and the light emitting device disclosed by the utility model embodiment can improve yield and light emitting performance through the design that the optical glue surrounds the ring side surface of the light emitting chip, and the top surface and the bottom surface of the light emitting chip are exposed outside the optical glue.

[0080] The above is only the preferred and feasible embodiment of the utility model, and is not used to limit the protection scope of the utility model, and any equivalent change and modification made according to the utility model claim shall belong to the protection scope of the utility model claim.

Claims

1. A light emitting unit, characterized by The light emitting unit comprises: a light emitting chip having a top surface and a bottom surface opposite to each other in a thickness direction and a ring side surface surrounding the top surface and the bottom surface, the bottom surface of the light emitting chip having a connection pad, and the top surface of the light emitting chip having a wire bonding pad; and an optical adhesive surrounding the ring side surface of the light emitting chip and leaving the top surface and the bottom surface of the light emitting chip exposed outside the optical adhesive.

2. The light emitting unit according to claim 1, characterized in that The optical adhesive forms a recess adjacent to the connection pad.

3. The light emitting unit according to claim 2, characterized in that The cross section of the recess along the thickness direction is in two arc shapes.

4. The light emitting unit according to claim 1, characterized in that The light emitting chip has a first minimum thickness along the thickness direction, and the optical adhesive has a second minimum thickness along the thickness direction, the first minimum thickness being greater than the second minimum thickness.

5. The light emitting unit according to claim 4, characterized in that The second minimum thickness is between 75% and 85% of the first minimum thickness.

6. The light emitting unit of claim 1, wherein, The optical adhesive comprises a plurality of functional particles.

7. The light emitting unit according to claim 6, characterized in that The plurality of functional particles comprises at least one of light reflecting particles, dyed particles, light diffusing particles, light absorbing particles and fluorescent particles.

8. The light emitting unit of claim 1, wherein, The top surface of the light emitting chip has a first height position, and the optical adhesive comprises a mesa having a second height position lower than the first height position, so that a portion of the ring side surface adjacent to the top surface is exposed outside the optical adhesive.

9. The light emitting unit according to claim 8, characterized in that There is a height difference between the first height position and the second height position, and the height difference is less than 50% of the thickness of the light emitting chip along the thickness direction.

10. The light emitting unit according to claim 9, characterized in that The height difference is between 10 and 15 microns.

11. The light emitting unit of claim 8, wherein, The width of the mesa is not less than 30 microns.

12. A light emitting device comprising the light emitting unit according to claim 1, characterized by The light emitting device comprises: a substrate comprising a first circuit and a second circuit, and the light emitting unit is disposed on the substrate; and an encapsulation adhesive disposed on the substrate and covering the light emitting unit; wherein the light emitting chip is die bonded to the first circuit through the connection pad, the wire bonding pad is bonded to the second circuit through a conductive wire of the light emitting device, and the conductive wire is not covered by the optical adhesive.

13. The light emitting device of claim 12, wherein, The light emitting device further comprises a fence surrounding the encapsulation adhesive.

14. The light emitting device of claim 12, wherein The optical adhesive forms a recess adjacent to the connection pad, and the recess is filled with the encapsulation adhesive.

15. The light emitting device of claim 12, wherein The light emitting device comprises a plurality of the light emitting units.

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