CN114361150A

CN114361150A - Surface mounting device and display module

Info

Publication number: CN114361150A
Application number: CN202111655297.1A
Authority: CN
Inventors: 韵夏伟; 陈振彰; 高博
Original assignee: BOE Technology Group Co Ltd; BOE Jingxin Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; BOE Jingxin Technology Co Ltd
Priority date: 2021-12-30
Filing date: 2021-12-30
Publication date: 2022-04-15

Abstract

The embodiment of the application provides a surface-mounted device and a display module, which comprise a device substrate, a light-emitting device, a control device, a connecting wire and a connecting bonding pad; the device substrate comprises a first surface and a second surface which are opposite, the light-emitting device is arranged on the first surface, the connecting pad is arranged on the second surface, and the control device is arranged on the first surface or the second surface; the connecting wire is connected with the connecting bonding pad, the light-emitting device and the control device. After the surface mounting device provided by the embodiment of the application is mounted on the PCB substrate to form the display module, the control device in the surface mounting device can be used for controlling the light-emitting device in the working process of the display module, so that the dependence on the PCB substrate is reduced, the processing pressure of the PCB substrate is reduced, and the control on the light-emitting device is simpler and more flexible.

Description

Surface mounting device and display module

Technical Field

The embodiment of the application relates to the technical field of display devices, in particular to a surface mounting device and a display module.

Background

The sub-millimeter Light Emitting Diode (Mini LED) display module or the Micro LED (Micro LED) display module uses the Mini LED/Micro LED as a display module of a Light Emitting device, and the Mini LED/Micro LED has the advantages of self-luminescence, wide viewing angle, fast response, simple structure, long service life and the like, and has a wide application prospect.

In the related art, a Mini LED/Micro LED display module includes a PCB (Printed Circuit Board) substrate and a Mini LED/Micro LED chip disposed on the PCB substrate; the Mini LED/Micro LED chip can be Mounted on the PCB substrate by Surface Mounted Technology (SMT). Specifically, a Mini LED/Micro LED chip is fixed on a support, the Mini LED/Micro LED chip and a welding spot are connected through a gold wire, and then the protection is performed through epoxy resin, so that a Surface Mounted device (abbreviated as SMD) is formed. And the SMD connects the welding points with the PCB substrate through reflow soldering to form the display module.

In the display module, the control of the Mini LED/Micro LED chip depends on the PCB substrate, so that the display module has certain limitation, for example, the difficulty in realizing active driving is high.

Disclosure of Invention

In view of the above, an object of the present invention is to provide a surface mount device and a display module.

In a first aspect, an embodiment of the present application provides a surface mount device, including a device substrate, a light emitting device, a control device, a connection trace, and a connection pad;

the device substrate comprises a first surface and a second surface which are opposite, the light-emitting device is arranged on the first surface, the connecting pad is arranged on the second surface, and the control device is arranged on the first surface or the second surface; the connecting wire is connected with the connecting bonding pad, the light-emitting device and the control device.

After the surface mounting device provided by the embodiment of the application is mounted on the PCB substrate to form the display module, the control device in the surface mounting device can be used for controlling the light-emitting device in the working process of the display module, the dependence on the PCB substrate is reduced, the processing pressure of the PCB substrate is reduced, the control on the light-emitting device is simpler and more flexible, and the expandability is strong. For example, the active driving of the display module can be realized by using the driving chip in the surface mount device, and the display module is low in cost and high in economic benefit.

In a possible implementation manner, the device substrate includes a connection side connecting the first surface and the second surface, and the connection traces include a first trace located on the first surface, a second trace located on the second surface, and a third trace connecting the first trace and the second trace; the third wire is connected with the second wire on the second surface from the first surface through the connecting side surface.

In a possible embodiment, the connection side is provided with a transition slope at a connection position with the first surface and/or a connection position with the second surface, and the third trace extends to the connection side through the transition slope.

In a possible embodiment, the transition bevel is a chamfer arc formed by a chamfer or a chamfer bevel.

In a possible implementation manner, the device substrate has a rectangular plate-shaped structure, the connection side includes four sub-sides, and the third trace is routed on any one of the sub-sides.

In a possible implementation manner, the connection trace includes a first trace located on the first surface and a second trace located on the second surface, and the first trace and the second trace are connected by a via penetrating through the device substrate.

In one possible embodiment, the control device includes at least one of a driving chip, a driving circuit, and a control switch.

In a possible embodiment, the control device is arranged on the first surface.

In one possible embodiment, the light emitting device is a sub-millimeter light emitting diode or a micro light emitting diode.

In one possible embodiment, the light emitting devices include a red light emitting device, a green light emitting device and a blue light emitting device, and the control device includes a micro driving chip having the same size class as the light emitting devices, and the red light emitting device, the green light emitting device and the blue light emitting device are electrically connected to the micro driving chip.

In one possible embodiment, the surface mount device is further provided with an optical encapsulation layer on the first surface.

In one possible embodiment, the connection trace comprises a copper/copper nickel alloy, or molybdenum/aluminum/molybdenum.

In one possible embodiment, the device substrate is a glass substrate, a quartz substrate, or a plastic substrate.

In a second aspect, an embodiment of the present application provides a display module, including a module substrate and a plurality of surface mount devices according to any one of the embodiments of the first aspect, the module substrate is a printed circuit board, a substrate pad is provided on the module substrate, and a connection pad of the surface mount device is connected to the substrate pad.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments or related technologies of the present application, the drawings needed to be used in the description of the embodiments or related technologies are briefly introduced below, it is obvious that the drawings in the following description are only one or more embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a display module according to an embodiment of the present disclosure;

fig. 2 is a first schematic structural diagram of a surface mount device according to an embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a surface mount device according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of a transition bevel in a surface mount device according to an embodiment of the present disclosure;

fig. 5A to fig. 5E are schematic diagrams illustrating a method for manufacturing a surface mount device according to an embodiment of the present disclosure.

Description of reference numerals:

the LED module comprises a 1-module substrate, a 2-surface mounting device, a 3-substrate bonding pad, a 4-device substrate, a 41-first surface, a 42-connection side face, a 43-second surface, a 44-transition inclined face, a 5-driving chip, a 6-light emitting device, a 7-connection wiring, a 71-first wiring, a 72-third wiring, a 73-second wiring and an 8-connection bonding pad.

Detailed Description

In the related art, a Mini LED/Micro LED display module includes a PCB (Printed Circuit Board) substrate and a Mini LED/Micro LED disposed on the PCB substrate; the Mini LED/Micro LED may be disposed on the PCB substrate by Surface Mounted Technology (SMT). Specifically, a Mini LED/Micro LED bare chip is fixed on a support, the Mini LED/Micro LED bare chip and a welding spot are connected through a gold wire, and then the Surface Mounted Devices (abbreviated as SMD) are formed by protecting with epoxy resin. And the SMD connects the welding spots with the welding pads on the PCB substrate through reflow soldering to form the display module.

In the display module, the Mini LED/Micro LED depends on the PCB substrate, which has certain limitations, for example, it is difficult to realize an Active Matrix (abbreviated as AM) driving mode, which is difficult to realize, and may cause problems of strong screen flicker and long-term viewing visual fatigue. If the active driving chip is directly adopted on the PCB substrate, the required driving chip has larger size and higher cost.

In view of this, an embodiment of the present application provides a surface mount device and a display module, where the surface mount device includes a substrate, and a light emitting device, a micro driver chip, a connection trace and a connection pad mounted on the substrate, where the light emitting device and the connection pad are disposed on two sides of the substrate, and the connection trace implements connection of the light emitting device, the micro driver chip and the connection pad.

By the design, in the working process of the display module, the micro driving chip in the surface mounting device can be used for controlling the light-emitting device, the dependence on the PCB substrate and the processing pressure of the PCB substrate are reduced, the control on the light-emitting device is simpler, and the expandability is strong. For example, the micro driving chip can be used for realizing the active driving of the display module, and the cost is low and the economic benefit is high.

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Fig. 1 is a schematic structural diagram of a display module according to an embodiment of the present application, and as shown in fig. 1, the display module includes a module substrate 1 and a plurality of light emitting devices disposed on one side of the module substrate 1, the module substrate 1 is a PCB (Printed Circuit Board) substrate, and a substrate pad 3 connected to the light emitting devices is disposed on the PCB substrate. The light emitting device is connected to the PCB substrate through the connection to the substrate pad 3.

The light emitting device may be a sub-millimeter light emitting diode (Mini LED) or a Micro light emitting diode (Micro LED). The Mini LED is an LED chip with the grain size of about 100-300 μm, and the Micro LED is an LED chip with the grain size of less than 100 μm. The Mini LED/Micro LED can be used as a self-luminous LED for display, has the advantages of low power consumption, high brightness, high resolution, high color saturation, high reaction speed, long service life, high efficiency and the like, and has wide application prospect.

The Mini LED/Micro LED can be arranged on the PCB substrate by adopting a Surface Mounted Technology (abbreviated as SMT), and the SMT process has the advantages of high automation degree and reliability and the like, and is particularly suitable for assembling the Mini LED/Micro LED display module with small spacing.

In a product assembled by using the SMT process, a Surface Mounted Device (SMD) 2 including a Mini LED/Micro LED bare chip is formed. That is, in fig. 1, a plurality of surface mount devices 2 are disposed above the PCB substrate, and the surface mount devices 2 are mounted on the substrate pads 3 by an SMT process, so as to connect the light emitting devices to the PCB substrate.

The embodiment of the application provides a surface mount device, fig. 2 is a schematic structural diagram of a surface mount device provided by the embodiment of the application, fig. 3 is a schematic structural diagram of a surface mount device provided by the embodiment of the application, fig. 2 and fig. 3 show that the surface mount device 2 includes a device substrate 4, a light emitting device 6, a driving chip 5, a connecting trace 7 and a connecting pad 8, wherein the light emitting device 6 selects a Mini LED/Micro LED, can be a monochromatic light emitting device, can also include monochromatic light emitting devices with different colors, and color display is realized through combination of different colors. For example, in the present embodiment, the light emitting device 6 includes a red (R) light emitting device, a green (G) light emitting device, and a blue (B) light emitting device.

The driving chip 5 is a micro driving chip having the same size level as the light emitting device 6, for example, the size of the micro driving chip corresponding to the Mini LED is 100 μm to 300 μm; the size of the Micro driving chip corresponding to the Micro LED is below 100 μm, and the red (R), green (G) and blue (B) light emitting devices are all connected with the same driving chip 5 and display is performed under the control of the same driving chip 5.

The device substrate 4 has a plate-like structure having a certain rigidity, and may be made of a material such as glass, quartz, or plastic, or may have any shape, for example, a rectangular plate, a rhombic plate, or a circular plate. In the present embodiment, the device substrate 4 is illustrated as a rectangular glass substrate, the device substrate 4 includes a first surface 41 and a second surface 43 opposite to each other, and a connecting side surface 42 connecting the first surface 41 and the second surface 43, and the connecting side surface 42 includes four sub-side surfaces. The light emitting device 6 and the driving chip 5 are disposed at the first surface 41, and the connection pad 8 is disposed at the second surface 43. The specific number of the connection pads 8 is related to the control mode and the control purpose of the driving chip 5, and is not listed here.

The connection trace 7 includes a first trace 71 on the first surface 41, a second trace 73 on the second surface 43, and a third trace 72 connecting the first trace 71 and the second trace 73, wherein the third trace 72 extends in any sub-side of the connection sides 42. That is, the connection trace 7 realizes the connection of the first trace 71 and the second trace 73 by means of a trace on the side of the glass substrate. The connection trace 7 may be a copper/copper nickel alloy laminate or a molybdenum/aluminum/molybdenum laminate. Since the connection trace 7 typically comprises a plurality of traces, in a possible embodiment, the third trace 72 in the connection trace 7 may extend traces through different sub-sides.

To facilitate the provision of the third trace 72, the connecting side 42 is provided with a transition slope at the connecting position with the first surface 41. Fig. 4 is a schematic structural diagram of a transition bevel 44 in a surface mount device according to an embodiment of the present disclosure, and as shown in fig. 4, the transition bevel 44 is a straight surface inclined with respect to the first surface 41 and the connecting side surface, and may be implemented by a chamfering process. In other possible embodiments, the transition slope 44 may be a circular arc surface, which may be realized by a chamfering process.

The end of the third trace 72 near the first surface 41 is connected to the first trace 71 on the first surface 41, extends from the first surface 41 to the second surface 43 through the transition slope 44 and the connecting side 42, and is connected to the second trace 73 on the second surface 43. By arranging the transition inclined plane 44, the second wire 73 positioned on the second surface 43 can be exposed, and when the third wire 72 is manufactured on the chamfer inclined plane, the connection between the first wire 71 and the second wire 73 can be directly realized, so that the processing and manufacturing of the connection wire 7 are facilitated; and the large-angle bending of the connecting wire 7 can be avoided, and the connecting possibility is ensured.

In other possible embodiments, the connecting flank 42 is provided with a transition bevel 44 at the connecting location with the second surface 43 by a chamfering process, or the connecting flank 42 is provided with a transition bevel 44 at both the connecting location with the first surface 41 and the connecting location with the second surface 43.

The third trace 72 is made of a metal material at the bevel edge by a patterning process, and it should be noted that the "patterning process" mentioned herein includes processes of depositing a film, coating a photoresist, exposing a mask, developing, etching, and stripping the photoresist, and is a well-known and mature preparation process. The deposition may be performed by known processes such as sputtering, evaporation, chemical vapor deposition, etc., the coating may be performed by known coating processes, and the etching may be performed by known methods, which are not limited herein.

The surface mount device 2 may further include an optical package layer on the first surface 41, the optical package layer covering the light emitting device 6, the driving chip 5, and the first trace 71, where the optical package layer is used to package and protect the light emitting device 6, the driving chip 5, and the first trace 71, and may also optically adjust the light emitted from the light emitting device 6. For example, in a possible embodiment, the optical packaging layer may include a black packaging layer, and the black packaging layer may be a composite black film for blackening the surface mount device 2; for another example, in another possible embodiment, the optical encapsulation layer is a transparent encapsulation layer, which may be used when the surface mount device 2 is used as a backlight.

In the surface mounting device 2 provided by the embodiment of the application, the side routing of the glass substrate is utilized to lead the routing of the driving chip 5 and the light-emitting device 6 to the back surface, and the side routing is connected with the connecting pad 8 positioned on the back surface, and the connecting pad 8 is used for being connected with the substrate pad 3 on the PCB substrate when being mounted with the PCB substrate; the surface mounting device 2 is mounted on the PCB through an SMT process to form a display module.

In the work of display module assembly, display module assembly can utilize driver chip 5 among the surface mounting device 2 to control luminescent device 6 to can reduce the control dependence to the PCB base plate, alleviate the control pressure of PCB board, make display module assembly's control simpler, scalability is strong. For example, in a possible embodiment, the micro driver chip 5 can be used to realize active driving, which is low in cost and high in economic benefit.

In the above embodiment, the driving chip is taken as an example for explanation, but the embodiment of the present application is not limited to this, for example, the driving chip may be replaced by an active control device such as a driving circuit and a control switch to realize control over the light emitting device 6, and the active control device may be provided in multiple types or multiple types, and the working principle of the active control device is the same as that of the driving chip, and is not described here again.

In view of the above, the present embodiment also provides a method for manufacturing a surface mount device 2, please refer to fig. 5A to 5E;

step 1: as shown in fig. 5A, a large glass plate 10 is provided, and front circuits and back circuits are formed on front and back sides of the large glass plate 10 in regions; the glass large plate 10 is a glass substrate with a large area and is used for manufacturing a plurality of surface mount devices simultaneously;

the front and back traces may be copper/copper nickel alloy (Cu or CuNi), or molybdenum/aluminum/molybdenum (Mo/Al/Mo).

Step 2: cutting the large glass plate 10 to form a sub glass plate 20 in a strip shape, wherein the sub glass plate 20 is a rectangular plate, and the length of the strip shape is at least 10 times of the width;

for example, in some specific products, the sub-glass plates 20 may be 100-200mm long and 5-10mm wide, as shown in FIG. 5B.

And step 3: chamfering is performed on both long side positions of the sub glass plate 20, and the right-angled edges are cut off to form chamfered slopes 30, as shown in fig. 5C.

And 4, step 4: performing side wiring connection by a sputtering (sputter) method, and connecting the lead of the front wiring 40 and the back wiring 50 together by a side wiring 60; as shown in fig. 5D, the left side view is a front view of the sub glass plate 20, and the right side view is a back view of the sub glass plate 20.

And 5: the sub-glass plate 20 is then placed in a die bonder, which sequentially bonds the light emitting devices 6 and the driving chips 5 to the front surface lines 40, as shown in fig. 5E.

Step 6: the composite optical adhesive material is adopted, and optical packaging is carried out through injection Molding (Molding) or adhesive dispensing and film pasting, so that the problems of protecting the light-emitting device 6 and the driving chip 5 and optical light mixing and light extraction are solved. In a possible embodiment, the composite optical cement comprises a composite black film for blackening treatment.

And 7: the packaged samples were cut to SMD size.

The surface mount device in the above embodiment can be manufactured through the above steps. Optionally, point measurement can be performed through the connecting pad on the back surface, so that sorting before delivery is realized.

In a possible embodiment, the scheme of side routing can also be replaced by a single-sided backplane process and a flexible mask. In the process of leading wires to the back surface, after the front surface circuit is manufactured by means of the flexible mask plate, the flexible mask plate is attached to the back surface and is rolled on the side edge for sputtering, the side surface circuit and the back surface circuit can be manufactured at the same time, the manufacturing process is simplified, and the manufacturing efficiency is higher.

In a possible embodiment, the first and

second traces

71, 73 may be connected by vias that extend through the device substrate 4.

In addition, although the light emitting device in the above embodiment is described by taking RGB pixel combination as an example, the embodiment of the present application may be applied to a display module with any pixel combination, for example, RGBW, RGBB, RGBG, and other pixel combinations may also be used.

The surface mount device in other embodiments may be manufactured by the above manufacturing method, and details are not described herein.

In the description of the embodiments of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be configured in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the embodiments of the present application, it should be noted that the terms "mounted," "connected," and "connected" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected unless explicitly stated or limited otherwise; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. Specific meanings of the above terms in the embodiments of the present application can be understood in specific cases by those of ordinary skill in the art.

In addition, the technical features mentioned in the different embodiments of the present application can be combined with each other as long as they do not conflict with each other.

So far, the technical solutions of the present application have been described in connection with the preferred embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of the present application is obviously not limited to these specific embodiments. Equivalent changes or substitutions of related technical features can be made by those skilled in the art without departing from the principle of the present application, and the technical scheme after the changes or substitutions will fall into the protection scope of the present application.

Claims

1. A surface mounting device is characterized by comprising a device substrate, a light-emitting device, a control device, a connecting wire and a connecting bonding pad;

2. A surface mount device according to claim 1, wherein the device substrate includes a connection side connecting the first surface and the second surface, the connection traces include a first trace on the first surface, a second trace on the second surface, and a third trace connecting the first trace and the second trace; the third wire is connected with the second wire on the second surface from the first surface through the connecting side surface.

3. The surface mount device according to claim 2, wherein the connection side is provided with a transition slope at a connection position with the first surface and/or a connection position with the second surface, and the third trace extends to the connection side through the transition slope.

4. A surface mount device according to claim 3, wherein said transition chamfer is a chamfer arc formed by a chamfer or a chamfer.

5. The surface mount device according to claim 3, wherein the device substrate has a rectangular plate-like structure, the connection side includes four sub-sides, and the third trace is routed on any one of the sub-sides.

6. The surface mount device according to claim 1, wherein the connection traces include a first trace on the first surface and a second trace on the second surface, and the first trace and the second trace are connected by a via penetrating through the device substrate.

7. A surface mount device according to claim 1, wherein said control means comprises at least one of a driver chip, a driver circuit and a control switch.

8. A surface mount device according to claim 7, wherein said control means is provided on said first surface.

9. A surface mount device according to claim 1, wherein the light emitting device is a sub-millimeter light emitting diode or a micro light emitting diode.

10. A surface mount device according to claim 9, wherein the light emitting devices include a red light emitting device, a green light emitting device, and a blue light emitting device, and the control means includes a micro driving chip having the same size class as the light emitting devices, and the red light emitting device, the green light emitting device, and the blue light emitting device are electrically connected to the micro driving chip.

11. A surface mount device according to claim 1, further provided with an optical encapsulation layer on the first surface.

12. A surface mount device according to claim 1, wherein the connection trace comprises a copper/copper nickel alloy, or molybdenum/aluminum/molybdenum.

13. A surface mount device according to claim 1, wherein the device substrate is a glass substrate, a quartz substrate, or a plastic substrate.

14. A display module comprising a module substrate and a plurality of surface mount devices according to any one of claims 1 to 13, wherein the module substrate is a printed circuit board, the module substrate is provided with a substrate pad, and the connection pad of the surface mount device is connected to the substrate pad.