Circuit board, backlight source, image generation unit and head-up display system

Abstract

The present disclosure relates to a circuit board, a backlight source, an image generation unit and a head-up display system. The circuit board is used to connect at least two light-emitting modules, including a metal substrate; a first dielectric layer, located on one side of the metal substrate; a circuit layer arranged in a stacked manner, located on the side of the first dielectric layer away from the metal substrate; the circuit layer includes a first circuit layer and at least one second circuit layer, and the at least one second circuit layer is located on the side of the first circuit layer away from the first dielectric layer; the second dielectric layer is located between two adjacent circuit layers; an installation port, at least one second circuit layer and one second dielectric layer are penetrated, and the circuit layer covered by the second dielectric layer is exposed; at least two light-emitting modules are electrically connected to the circuit layers exposed by the installation port, respectively, and are configured to be independently controlled from each other. The circuit board increases the wiring area, thereby reducing the wiring density and wiring difficulty; it also reduces the number of dielectric layers that the light-emitting module needs to pass through to dissipate heat downward, effectively improving the heat dissipation efficiency of the circuit board.

Description

Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to a circuit board, a backlight source, an image generation unit and a head-up display system. Background Art

[0002] The head-up display system (HUD) projects the light emitted by the image generation unit onto the imaging window (rear-mounted imaging board or vehicle windshield, etc.), so that users can see the image directly without lowering their heads, thereby improving driving safety and providing a better driving experience.

[0003] In the related art, the screen size of the image generating unit is usually relatively small. If the backlight source requires a large amount of wiring, it may cause the LED to be unable to be routed normally, and it may also have an adverse effect on the heat dissipation efficiency of the circuit board. Summary of the invention

[0004] In order to solve the above technical problems, the present disclosure provides a circuit board, a backlight source, an image generating unit and a head-up display system.

[0005] In a first aspect, the present disclosure provides a circuit board for connecting at least two light-emitting modules, the circuit board comprising:

[0006] metal substrate;

[0007] A first dielectric layer, located on one side of the metal substrate;

[0008] The stacked circuit layer is located on the side of the first dielectric layer away from the metal substrate; the circuit layer includes a first circuit layer and at least one second circuit layer, and the at least one second circuit layer is located on the side of the first circuit layer away from the first dielectric layer;

[0009] A second dielectric layer is located between two adjacent circuit layers;

[0010] The installation opening penetrates at least one layer of the second circuit layer and one layer of the second dielectric layer, and exposes the circuit layer covered by the second dielectric layer;

[0011] Among them, at least two light-emitting modules are electrically connected to the circuit layer exposed by the mounting opening respectively; and at least two of the light-emitting modules are configured to control the light-emitting brightness independently of each other.

[0012] Optionally, the installation opening passes through all the circuit layers and all the second dielectric layers;

[0013] The light-emitting module is electrically connected to the first circuit layer exposed on the side wall of the installation opening.

[0014] Optionally, the circuit board further includes:

[0015] A first solder pad, located in the mounting opening, for connecting the light-emitting module and the circuit layer;

[0016] The thickness of the first solder pad is smaller than the depth of the mounting opening, and the light-emitting module connected to the first solder pad is at least partially located in the mounting opening.

[0017] Optionally, the circuit board further includes:

[0018] A second solder pad, located in the mounting opening, for connecting the light-emitting module and the circuit layer;

[0019] The thickness of the second solder pad is greater than or equal to the depth of the mounting opening, and the light-emitting module connected to the second solder pad is located outside the mounting opening.

[0020] Optionally, the thickness H1 of the metal substrate satisfies: 0.5 mm ≤ H1 ≤ 3 mm; and / or,

[0021] The thickness H2 of the circuit layer satisfies: 15 μm ≤ H2 ≤ 70 μm; and / or,

[0022] The thickness H3 of the first dielectric layer satisfies: 30 μm≤H3≤100 μm; and / or,

[0023] The thickness H4 of the second dielectric layer satisfies: 30 μm ≤ H4 ≤ 100 μm; and / or,

[0024] The diagonal length L of the metal substrate satisfies: 2.1 inches ≤ L ≤ 6.7 inches.

[0025] Optionally, a gap D between the light-emitting module and the side wall of the mounting opening satisfies: 0.1 mm ≤ D ≤ 5 mm; and / or,

[0026] The second circuit layer is provided with a wiring area, and the installation opening is configured to avoid the wiring area corresponding to the second circuit layer when penetrating the second circuit layer.

[0027] Optionally, the circuit board further includes:

[0028] The insulating layer is filled in the gap between the light-emitting module and the side wall of the mounting opening.

[0029] Optionally, the circuit board further includes:

[0030] A protective layer; along the direction of the circuit layer pointing to the first dielectric layer, the protective layer is located on the side of the circuit layer away from the first dielectric layer, the protective layer covers the circuit layer and exposes the mounting port.

[0031] Optionally, the thickness H5 of the protective layer satisfies: 15 μm≤H5≤25 μm; and / or,

[0032] The insulating layer and the protective layer are made of the same material.

[0033] In a second aspect, the present disclosure further provides a backlight source, comprising: at least two light-emitting modules and any one of the above-mentioned circuit boards; wherein the light-emitting module comprises at least one light-emitting diode.

[0034] In a third aspect, the present disclosure further provides an image generation unit, comprising: a display panel and the above-mentioned backlight source;

[0035] Wherein, the display panel includes at least two display areas, and the display areas correspond one-to-one to the light-emitting modules of the backlight source; the backlight source is configured to determine the target brightness of the corresponding light-emitting module according to the brightness information of each display area of ​​the display panel.

[0036] In a fourth aspect, the present disclosure further provides a head-up display system, comprising: an image generating unit as described above.

[0037] Compared with the prior art, the technical solution provided by the present invention has the following advantages:

[0038] The present disclosure provides a circuit board, a backlight source, an image generation unit and a head-up display system, wherein the circuit board is used to connect at least two light-emitting modules, and the circuit board includes: a metal substrate; a first dielectric layer, located on one side of the metal substrate; a stacked circuit layer, located on the side of the first dielectric layer away from the metal substrate; the circuit layer includes a first circuit layer and at least one second circuit layer, and at least one second circuit layer is located on the side of the first circuit layer away from the first dielectric layer; the second dielectric layer is located between two adjacent circuit layers; an installation port, at least one second circuit layer and one second dielectric layer are penetrated, and the circuit layer covered by the second dielectric layer is exposed; wherein at least two light-emitting modules are respectively electrically connected to the circuit layers exposed by the installation port; and at least two light-emitting modules are configured to be independently controlled from each other. Thus, the circuit board includes the first circuit layer and at least one second circuit layer, which increases the wiring area, thereby reducing the wiring density and wiring difficulty; at the same time, by setting the installation port penetrating the second circuit layer and the second dielectric layer, the number of dielectric layers that the light-emitting module needs to pass through to dissipate heat downward is reduced, and the heat dissipation efficiency of the circuit board is effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0040] In order to more clearly illustrate the embodiments of the present invention 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, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0041] Figure 1 It is a structural schematic diagram of a circuit board in the related art;

[0042] Figure 2 A schematic diagram of the structure of a circuit board provided in an embodiment of the present disclosure;

[0043] Figure 3 A schematic diagram of the structure of a backlight source provided by an embodiment of the present disclosure;

[0044] Figure 4 A schematic diagram of the structure of another circuit board provided in an embodiment of the present disclosure;

[0045] Figure 5 A schematic diagram of the structure of another backlight source provided by an embodiment of the present disclosure;

[0046] Figure 6 A schematic diagram of the structure of another circuit board provided in an embodiment of the present disclosure;

[0047] Figure 7 A schematic diagram of the structure of another backlight source provided by an embodiment of the present disclosure;

[0048] Figure 8 A schematic diagram of the structure of another backlight source provided by an embodiment of the present disclosure;

[0049] Fig. 9 A schematic diagram of the structure of another backlight source provided by an embodiment of the present disclosure;

[0050] Fig.10 A schematic diagram of the structure of another backlight source provided by an embodiment of the present disclosure;

[0051] Fig.11 A schematic diagram of the structure of another backlight source provided by an embodiment of the present disclosure;

[0052] Fig.12 A schematic diagram of the structure of another backlight source provided by an embodiment of the present disclosure;

[0053] Fig.13 A schematic diagram of the structure of another backlight source provided by an embodiment of the present disclosure;

[0054] Fig.14 A schematic diagram of the structure of another backlight source provided by an embodiment of the present disclosure;

[0055] Fig.15 A circuit diagram of a backlight source provided by an embodiment of the present disclosure;

[0056] Fig.16 A schematic diagram of the structure of a head-up display system provided in an embodiment of the present disclosure;

[0057] Fig.17 A schematic diagram of the structure of a head-up display system provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0058] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0059] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0060] In order to solve at least one of the problems of insufficient HUD brightness, excessive power consumption due to brightness requirements, and damage to LED lamp beads due to excessive temperature in the HUD, the inventors found that by setting the image generation unit with backlight control capabilities, that is, setting the backlight source to be controlled by different regions, the on / off and / or brightness of the backlight in each region can be controlled independently and adjusted separately, thereby realizing intelligent adjustment of the backlight source, and while meeting the brightness requirements of each display content in the virtual image, the power consumption and heat generation of the backlight source can be reduced as much as possible, and the LED lamp beads can be prevented from being damaged due to excessive temperature. However, the screen size of the image generation unit is usually relatively small, and the backlight source regional control requires a lot of wiring, which may cause the LED to be unable to connect and route normally, and will also have an adverse effect on the heat dissipation efficiency of the circuit board.

[0061] For example, a multi-layer circuit board is used to increase the wiring area, thereby reducing the wiring density and wiring difficulty. However, a dielectric layer is set between the circuit layers in the multi-layer circuit board for pressing and connecting the circuit layers, and the thermal conductivity of the dielectric layer is generally low, which will seriously affect the heat dissipation effect of the circuit board. For example, the thermal conductivity of the dielectric layer is 2W / m·k, and the thermal conductivity of the aluminum substrate is 237W / m·k. Each additional dielectric layer will reduce the overall heat dissipation efficiency of the circuit board. For example, Figure 1As shown, two circuit layers 103' and two dielectric layers 102' are arranged above the substrate 101', and the LED is connected to the top circuit layer 103', so that when the LED dissipates heat downward, it needs to pass through two dielectric layers 102' for heat dissipation, which will affect the heat dissipation efficiency of the LED; if the circuit board has more circuit layers 103', then the number of dielectric layers 102' that the LED needs to pass through when dissipating heat downward will be more, which will further affect the heat dissipation efficiency of the circuit board.

[0062] In order to solve the above technical problems, the embodiment of the present disclosure provides a circuit board, a backlight source, an image generation unit and a head-up display system, wherein the circuit board is used to connect at least two light-emitting modules, and the circuit board includes: a metal substrate; a first dielectric layer, located on one side of the metal substrate; a stacked circuit layer, located on the side of the first dielectric layer away from the metal substrate; the circuit layer includes a first circuit layer and at least one second circuit layer, and at least one second circuit layer is located on the side of the first circuit layer away from the first dielectric layer; the second dielectric layer is located between two adjacent circuit layers; an installation port, at least one second circuit layer and one second dielectric layer are penetrated, and the circuit layer covered by the second dielectric layer is exposed; wherein at least two light-emitting modules are electrically connected to the circuit layers exposed by the installation port respectively; and at least two light-emitting modules are configured to be controlled independently of each other. Thus, the circuit board includes the first circuit layer and at least one second circuit layer, which increases the wiring area, thereby reducing the wiring density and wiring difficulty; at the same time, by setting the installation port penetrating the second circuit layer and the second dielectric layer, the number of dielectric layers that the light-emitting module needs to pass through to dissipate heat downward is reduced, and the heat dissipation efficiency of the circuit board is effectively improved.

[0063] The circuit board, backlight source, image generation unit and head-up display system provided in the embodiments of the present disclosure are exemplarily described below in conjunction with the accompanying drawings.

[0064] In some embodiments, Figure 2-7 As shown, the circuit board 100 is used to connect at least two light-emitting modules 200, including: a metal substrate 101; a first dielectric layer 102, located on one side of the metal substrate 101; a stacked circuit layer 103, located on the side of the first dielectric layer 102 away from the metal substrate 101; the circuit layer 103 includes a first circuit layer 1031 and at least one second circuit layer 1032, and the at least one second circuit layer 1032 is located on the side of the first circuit layer 1031 away from the first dielectric layer 102; the second dielectric layer 104 is located between two adjacent circuit layers 103; an installation port 105, which passes through at least one second circuit layer 1032 and one second dielectric layer 104, and exposes the circuit layer 103 covered by the second dielectric layer 104; wherein, at least two light-emitting modules 200 are electrically connected to the circuit layer 103 exposed by the installation port 105 respectively; and at least two light-emitting modules 200 are configured to control the light-emitting brightness independently of each other.

[0065] The metal substrate 101 includes but is not limited to an aluminum substrate, and also includes other metal substrates 101 known to those skilled in the art, such as copper, silver, and gold, which are not limited here. The materials used for the first dielectric layer 102 and the second dielectric layer 104 can be the same or different, which are not limited here.

[0066] The circuit layer 103 includes at least two circuit layers 103, the circuit layer 103 at the bottom of the circuit layer 103 is the first circuit layer 1031, that is, the circuit layer 103 in contact with the first dielectric layer 102 is the first circuit layer 1031; the circuit layer 103 above the first circuit layer 1031 is the second circuit layer 1032, and the number of the second circuit layer 1032 is at least one layer; the second dielectric layer 104 is arranged between two adjacent circuit layers. For example, Figure 2 As shown, in the circuit board, the circuit layer 103 includes a first circuit layer 1031 and a second circuit layer 1032, and the second dielectric layer 104 is located between the first circuit layer 1031 and the second circuit layer 1032 to separate the first circuit layer 1031 and the second circuit layer 1032. Figure 4 and 6 As shown, in the circuit board, the circuit layer 103 includes a first circuit layer 1031 and two second circuit layers 1032 , and the second dielectric layer 104 is located between the first dielectric layer 102 and the second dielectric layer 104 , and between the two second dielectric layers 104 .

[0067] It should be noted that Figure 2 , 4 6 only exemplarily show that the number of layers of the circuit layer 103 is two or three, but does not constitute a limitation on the circuit board provided in the embodiment of the present disclosure. In other embodiments, the number of layers of the circuit layer 103 can be flexibly set according to requirements, which is not limited here.

[0068] Among them, an installation opening 105 is formed by opening downward from the top layer of the circuit board 100. Since the light-emitting module 200 needs to be electrically connected to the circuit layer 103, the installation opening 105 passes through at least one layer of the second circuit 1032 and one layer of the second dielectric layer 104, exposing the circuit layer 103 located below the second dielectric layer 104. The circuit layer 103 can be the first circuit layer 1031 or the second circuit layer 1032.

[0069] For example, Figure 2-3As shown, in the circuit board 100, the circuit layer 103 includes a first circuit layer 1031 and a second circuit layer 1032, the mounting opening 105 penetrates a second circuit layer 1032 and a second dielectric layer 104, exposing the first circuit layer 1031, and the light-emitting module 200 is electrically connected to the first circuit layer 1031. With such a configuration, the heat of the light-emitting module 200 only needs to pass through one dielectric layer to be conducted away through the metal substrate 101, thereby reducing the number of dielectric layers through which the heat passes, and improving the heat dissipation efficiency of the multi-layer circuit board.

[0070] For example, Figure 4-5 As shown, in the circuit board 100, the circuit layer 103 includes a first circuit layer 1031 and two second circuit layers 1032, the mounting opening 105 penetrates a second circuit layer 1032 and a second dielectric layer 104, exposing the second circuit layer 1032, and the light-emitting module 200 is electrically connected to the second circuit layer 1032. Compared with the related art, the number of dielectric layers through which heat passes is reduced, and the heat dissipation efficiency of the multi-layer circuit board is improved.

[0071] For example, Figure 6-7 As shown, in the circuit board 100, the circuit layer 103 includes a first circuit layer 1031 and two second circuit layers 1032, the mounting opening 105 penetrates the two second circuit layers 1032 and the two second dielectric layers 104, exposing the first circuit layer 1031, and the light-emitting module 200 is electrically connected to the first circuit layer 1031. With such a configuration, the heat of the light-emitting module 200 only needs to pass through one dielectric layer to be conducted away through the metal substrate 101, thereby reducing the number of dielectric layers through which the heat passes, and improving the heat dissipation efficiency of the multi-layer circuit board.

[0072] Among them, the luminous brightness of at least two light-emitting modules 200 is controlled independently of each other and can be adjusted separately, thereby realizing regional control of the backlight source. According to the distribution of the display image on the display panel, the brightness of the light-emitting module 200 corresponding to the display content area (that is, the display area where the display image is located) is increased to meet the brightness requirement of the clear virtual image 4, and the brightness of the light-emitting module 200 corresponding to the content-free area (that is, the perspective display area) is reduced. Since there is no display image distributed in this part of the display area, the light-emitting module 200 in this part of the display area may even be turned off to reduce power consumption and heat generation as much as possible to avoid damage to the light-emitting module 200 due to excessive temperature.

[0073] It should be noted that the circuit layers 103 are electrically connected, such as Figure 8As shown, in the circuit board 100, the circuit layer 103 includes a first circuit layer 1031 and a second circuit layer 1032, and a second dielectric layer 104 is provided between the first circuit layer 1031 and the second circuit layer 1032. The second dielectric layer 104 includes a through hole extending through its thickness, and a connecting structure for electrically connecting the first circuit layer 1031 and the second circuit layer 1032 is provided in the through hole. The connecting structure can be a metal columnar structure filled in the through hole, or a metal plating layer located on the inner wall of the through hole, which is not limited here.

[0074] The circuit board 100 provided in the embodiment of the present disclosure is used to connect at least two light-emitting modules 200, and the circuit board includes: a metal substrate 101; a first dielectric layer 102, located on one side of the metal substrate 101; a stacked circuit layer 103, located on the side of the first dielectric layer 102 away from the metal substrate 101; the circuit layer 103 includes a first circuit layer 1031 and at least one second circuit layer 1032, and the at least one second circuit layer 1032 is located on the side of the first circuit layer 1031 away from the first dielectric layer 102; the second dielectric layer 104 is located between two adjacent circuit layers 103; an installation port 105, which passes through at least one second circuit layer 1032 and one second dielectric layer 104, and exposes the circuit layer covered by the second dielectric layer 104; wherein the at least two light-emitting modules 200 are respectively electrically connected to the circuit layer 103 exposed by the installation port 105; and the at least two light-emitting modules 200 are configured to be independently controlled from each other. Therefore, the circuit board 100 includes a first circuit layer 1031 and at least one second circuit layer 1032, which increases the wiring area, thereby reducing the wiring density and wiring difficulty; at the same time, by setting a mounting port 105 that passes through the second circuit layer 1032 and the second dielectric layer 104, the number of dielectric layers that the light-emitting module 200 needs to pass through to dissipate heat downward is reduced, thereby effectively improving the heat dissipation efficiency of the circuit board.

[0075] In some embodiments, Fig. 9 As shown, in the circuit board, the mounting opening 105 penetrates all the circuit layers 103 and all the second dielectric layers 104 ; the light-emitting module 200 is electrically connected to the first circuit layer 1031 exposed on the side wall of the mounting opening 105 .

[0076] In this embodiment, the installation opening 105 passes through all the second circuit layers 1032, all the second dielectric layers 104 and the first circuit layer 1031. The heat of the light-emitting module 200 only needs to pass through the first dielectric layer 102 to reach the metal substrate 101, and does not need to pass through the first circuit layer 1031, thereby further improving the heat dissipation efficiency of the circuit board.

[0077] In some embodiments, Figure 10-12As shown in any of the figures, the circuit board also includes: a first solder pad, located in the mounting opening 105, for connecting the light-emitting module 200 and the circuit layer 103; wherein the thickness of the first solder pad is less than the depth of the mounting opening 105, and the light-emitting module 200 connected to the first solder pad is at least partially located in the mounting opening 105.

[0078] In this embodiment, the first pad is a conventional pad, and its thickness is less than the depth of the mounting opening 105. After the light-emitting module 200 is electrically connected to the first pad, the light-emitting module 200 sinks into the mounting opening 105, that is, in the thickness direction of the circuit board, the light-emitting module 200 overlaps with the mounting opening 105. The light-emitting module 200 may be partially located in the mounting opening 105, that is, the top surface of the light-emitting module 200 is higher than the top surface of the mounting opening 105; the light-emitting module 200 may also be completely located in the mounting opening 105, that is, the top surface of the light-emitting module 200 is lower than the top surface of the mounting opening 105, or the top surface of the light-emitting module 200 is flush with the top surface of the mounting opening 105. Compared with the related art, the sinking height of the light-emitting module 200 is equal to the depth of the mounting opening 105.

[0079] In some embodiments, Fig.13 Or as shown in 14, the circuit board also includes: a second solder pad, located in the mounting port 105, for connecting the light-emitting module 200 and the circuit layer; wherein the thickness of the second solder pad is greater than or equal to the depth of the mounting port 105, and the light-emitting module 200 connected to the second solder pad is located outside the mounting port 105.

[0080] In this embodiment, the second pad is a thickened pad, and its thickness is greater than or equal to the depth of the mounting opening 105. After the light-emitting module 200 is electrically connected to the second pad, the light-emitting module 200 is located outside the mounting opening 105, that is, in the thickness direction of the circuit board, the light-emitting module 200 and the mounting opening 105 do not overlap. Compared with the related art, the position height of the light-emitting module 200 does not change. The second pad is made of a conductive material with good thermal conductivity, such as solder paste. Special attention should be paid to parameter adjustment and equipment adjustment during the connection between the light-emitting module 200 and the second pad to ensure good welding effect and reliability.

[0081] In some embodiments, the thickness H1 of the metal substrate 101 satisfies: 0.5mm≤H1≤3mm; and / or, the thickness H2 of the circuit layer 103 satisfies: 15μm≤H2≤70μm; and / or, the thickness H3 of the first dielectric layer 102 satisfies: 30μm≤H3≤100μm; and / or, the thickness H4 of the second dielectric layer 104 satisfies: 30μm≤H4≤100μm; and / or, the diagonal length L of the metal substrate 101 satisfies: 2.1inch≤L≤6.7inch.

[0082] Furthermore, the preferred thickness of the metal substrate 101 is 1.2 mm; the preferred thickness of the circuit layer 103 is 35 μm; and the preferred thickness of the first dielectric layer 102 and the second dielectric layer 104 is 50 μm.

[0083] It should be noted that the embodiment of the present disclosure only exemplarily shows the thickness of each component film layer in the circuit board, but does not constitute a limitation on the circuit board provided by the embodiment of the present disclosure. In other embodiments, it can be flexibly set according to needs and is not limited here.

[0084] In some embodiments, Fig.10 As shown, the gap D between the light-emitting module 200 and the side wall of the installation opening 105 satisfies: 0.1mm≤D≤5mm; and / or, the second circuit layer 1032 is provided with a routing area, and the installation opening 105 is configured to avoid the corresponding routing area of ​​the second circuit layer 1032 when penetrating the second circuit layer 1032.

[0085] When opening the installation opening 105 , it is necessary to ensure that the size of the installation opening 105 is larger than the size of the light emitting module 200 , so that after the light emitting module 200 is installed, there is a certain gap between the light emitting module 200 and the side wall of the installation opening 105 , and the gap is 0.1 mm to 5 mm.

[0086] The first circuit layer 1031 and the second circuit layer 1032 are both provided with wiring areas, and the light-emitting module 200 is connected to the controller through the wiring in the circuit layer 103, so that the controller transmits control signals to the light-emitting module 200. The position of the mounting opening 105 should avoid the wiring area of ​​the second circuit layer 1032 to avoid damaging the wiring when opening the mounting opening 105, thereby affecting the transmission of the control signal of the light-emitting module 200.

[0087] It should be noted that for Fig. 9 In the circuit board shown, the installation opening 105 penetrates all the second circuit layers 1032 , all the second dielectric layers 104 and the first circuit layer 1031 , and the position of the installation opening 105 also needs to avoid the routing area of ​​the first circuit layer 1031 .

[0088] In some embodiments, Figure 10-14 As shown in any of the figures, the circuit board also includes: a protective layer 106; along the direction of the circuit layer 103 pointing to the first dielectric layer 102, the protective layer 106 is located on the side of the circuit layer away from the first dielectric layer 102, and the protective layer 106 covers the circuit layer 103 (ie, the second circuit layer 1032) and exposes the mounting port 105.

[0089] The protective layer 106 is located on the top surface of the circuit layer 103, covers the second circuit layer 1032 located on the top of the circuit layer 103, and has an opening at the location of the installation opening 105 to expose the installation opening 105. The protective layer 106 has insulation properties, such as a paint layer.

[0090] It should be noted that the installation opening 105 can be opened first, and then the protective layer 106 is coated on the top of the second circuit layer 1032; or the protective layer 106 can be coated on the top of the second circuit layer 1032, and then the installation opening 105 is opened, and the installation opening 105 needs to pass through the protective layer 106, at least one layer of the second circuit layer 1032 and a layer of the second dielectric layer 104; the protective layer 106 at the position of the installation opening 105 is removed by laser to expose the second circuit layer 1032 below.

[0091] In some embodiments, the thickness H5 of the protective layer 106 satisfies: 15 μm≤H5≤25 μm; preferably, the thickness H5 of the protective layer 106 is 20 μm.

[0092] In some embodiments, Fig.11 As shown, the circuit board further includes: an insulating layer 107 , which fills the gap between the light-emitting module 200 and the side wall of the mounting opening 105 .

[0093] The insulating layer 107 is filled in the gap between the light emitting module 200 and the side wall of the mounting opening 105 to achieve an insulating protection effect and prevent leakage.

[0094] In some embodiments, Fig.12 As shown, the insulating layer 107 is made of the same material as the protective layer 106 .

[0095] In this embodiment, an integrated insulating layer 107 and a protective layer 106 can be formed through one process, and the same insulating material layer (such as a paint layer) is arranged above the topmost second circuit layer 1032 and in the gap between the light-emitting module 200 and the side wall of the mounting port 105 to insulate and protect the circuit layer 103 to prevent leakage, while also simplifying the preparation process.

[0096] Based on the above implementation, the present disclosure also provides a backlight source. Figure 3 , 5 As shown in any one of Figures 7-8 and 10-14, the backlight source 11 includes: at least two light-emitting modules 200 and any one of the above-mentioned circuit boards 100; wherein the light-emitting module 200 includes at least one light-emitting diode; and has corresponding beneficial effects, which will not be repeated here to avoid repeated description.

[0097] The backlight source includes at least two light-emitting modules 200 , and each light-emitting module 200 includes at least one light-emitting diode.

[0098] For example, Fig.15 FIG. 1 is a schematic diagram of a circuit of a backlight source provided by an embodiment of the present disclosure. Fig.15 Each LED is controlled independently of each other and connected to the power bus through a single connection line. With this arrangement, the brightness of any LED of the backlight source can be controlled individually, thereby achieving regional control.

[0099] In other embodiments, the backlight source further includes all devices known to those skilled in the art, such as a collimating lens, which is not limited here.

[0100] On the basis of the above implementation, the embodiment of the present disclosure further provides an image generation unit 1. The image generation unit 1 comprises: a display panel and the above backlight source, the display panel is located at the light emitting side of the backlight source; wherein the display panel comprises at least two display areas, the display areas correspond one to one with the light emitting modules 200 of the backlight source; the backlight source is configured to determine the target brightness of the corresponding light emitting module 200 according to the brightness information of each display area of ​​the display panel; and has corresponding beneficial effects, which will not be described here in order to avoid repeated description.

[0101] In the related art, backlight is provided for all display areas of the display panel, that is, all the light-emitting elements in the backlight source are lit, and then the light energy of the light source light emitted by the corresponding light-emitting elements in the content-free area is converted into heat energy through shielding, refraction, reflection and absorption, so that no light is emitted from the content-free area. This method has problems such as high energy consumption and energy waste.

[0102] In this embodiment, the backlight source independently adjusts the light-emitting module 200 corresponding to each display area, independently controls the opening and closing and / or brightness of each light-emitting module 200, and realizes regional control. The backlight source can control the luminous brightness of the corresponding light-emitting module 200 to be the target brightness according to the brightness information of each display area of ​​the display panel. For example, according to the distribution of the display image on the display panel, the brightness of the light-emitting module 200 corresponding to the display content area (i.e., the display area where the display image is located) is increased to meet the brightness requirements of the clear virtual image 4, and the brightness of the light-emitting module 200 corresponding to the content-free area (i.e., the perspective display area) is reduced. Since there is no display image distribution in this part of the display area, the light-emitting module 200 in this part of the display area is even turned off, so as to reduce the power consumption and heat generation of the image generation unit 1 as much as possible, thereby reducing the damage of the LED due to excessive temperature, and at the same time improving the contrast.

[0103] It should be noted that the image generating unit 1 includes all components known to those skilled in the art, such as a polarization conversion element, an anti-reflection element, and an anti-glare film, etc., which are not limited here.

[0104] Based on the above implementation, the present disclosure also provides a head-up display system. Fig.16 As shown in or 17, the head-up display system includes: the image generation unit 1 as described above, which has corresponding beneficial effects, and will not be described here to avoid repeated description. At the same time, the head-up display system provided by the embodiment of the present disclosure can individually control each light-emitting module 200 (or light-emitting diode) of the backlight source for the image to be displayed, thereby avoiding turning on all the light-emitting modules 200 (or light-emitting diodes), but only turning on some of the light-emitting modules 200 (or light-emitting diodes), and by controlling the backlight of different areas corresponding to the image to be displayed, the backlight of some areas is turned off and the backlight of other areas is turned on, which not only improves the image contrast, but also can reduce the power consumption and heat generation of the backlight source by turning off the backlight of some areas or reducing the backlight brightness of some areas, thereby avoiding the backlight source from being damaged by high temperature.

[0105] The head-up display system provided in this embodiment is applied to transportation tools, and the transportation tools include but are not limited to land transportation tools such as vehicles, air transportation tools such as aircraft, and also water or underwater transportation tools. Fig.16 As shown, the head-up display system is applied to a vehicle.

[0106] For example, Fig.17 As shown, the head-up display system includes: an image generating unit 1 and a reflective imaging unit 2; wherein the image generating unit 1 is used to emit image light, and the image light is emitted to the reflective imaging unit 2 through an emission port 5; the reflective imaging unit 2 is located at the light emitting side of the image generating unit 1, and is configured to reflect the image light emitted by the image generating unit 1 to the eye box area 3, so that when the user's eyes are located in the eye box area 3, they can see the virtual image 4 formed on the side of the reflective imaging unit 2 away from the eye box area 3, and the objects located outside the reflective imaging unit 2. The head-up display system also includes an amplifying component, which is used to reflect the image light emitted by the image generating unit 1 to the reflective imaging unit 2, so as to amplify the image displayed in the image generating unit 1 into a virtual image 4; wherein the amplifying component may include a curved reflector 7, or include a curved reflector 7 and a plane reflector 6.

[0107] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0108] The above description is only a specific embodiment of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A circuit board, characterized in that: Used to connect at least two light-emitting modules, the circuit board comprises: metal substrate; A first dielectric layer, located on one side of the metal substrate; The stacked circuit layer is located on the side of the first dielectric layer away from the metal substrate; the circuit layer includes a first circuit layer and at least one second circuit layer, and the at least one second circuit layer is located on the side of the first circuit layer away from the first dielectric layer; A second dielectric layer is located between two adjacent circuit layers; The installation opening penetrates at least one layer of the second circuit layer and one layer of the second dielectric layer, and exposes the circuit layer covered by the second dielectric layer; Among them, at least two light-emitting modules are electrically connected to the circuit layer exposed by the mounting opening respectively; and at least two of the light-emitting modules are configured to control the light-emitting brightness independently of each other.

2. The circuit board according to claim 1, characterized in that: The installation opening passes through all the circuit layers and all the second dielectric layers; The light-emitting module is electrically connected to the first circuit layer exposed on the side wall of the installation opening.

3. The circuit board according to claim 1, characterized in that: Also includes: A first solder pad, located in the mounting opening, for connecting the light-emitting module and the circuit layer; The thickness of the first solder pad is smaller than the depth of the mounting opening, and the light-emitting module connected to the first solder pad is at least partially located in the mounting opening.

4. The circuit board according to claim 1, characterized in that: Also includes: A second solder pad, located in the mounting opening, for connecting the light-emitting module and the circuit layer; The thickness of the second solder pad is greater than or equal to the depth of the mounting opening, and the light-emitting module connected to the second solder pad is located outside the mounting opening.

5. The circuit board according to any one of claims 1 to 4, characterized in that: The thickness H1 of the metal substrate satisfies: 0.5 mm ≤ H1 ≤ 3 mm; and / or, The thickness H2 of the circuit layer satisfies: 15 μm ≤ H2 ≤ 70 μm; and / or, The thickness H3 of the first dielectric layer satisfies: 30 μm≤H3≤100 μm; and / or, The thickness H4 of the second dielectric layer satisfies: 30 μm ≤ H4 ≤ 100 μm; and / or, The diagonal length L of the metal substrate satisfies: 2.1 inches ≤ L ≤ 6.7 inches.

6. The circuit board according to any one of claims 1 to 4, characterized in that: The gap D between the light-emitting module and the side wall of the mounting opening satisfies: 0.1 mm ≤ D ≤ 5 mm; and / or, The second circuit layer is provided with a wiring area, and the installation opening is configured to avoid the wiring area corresponding to the second circuit layer when penetrating the second circuit layer.

7. The circuit board according to claim 6, characterized in that: Also includes: The insulating layer is filled in the gap between the light-emitting module and the side wall of the mounting opening.

8. The circuit board according to claim 7, characterized in that: Also includes: Protective layer; Along the direction from the circuit layer to the first dielectric layer, the protective layer is located on a side of the circuit layer away from the first dielectric layer, and the protective layer covers the circuit layer and exposes the mounting opening.

9. The circuit board according to claim 8, characterized in that: The thickness H5 of the protective layer satisfies: 15 μm ≤ H5 ≤ 25 μm; and / or, The insulating layer and the protective layer are made of the same material.

10. A backlight source, characterized in that: include: At least two light emitting modules and a circuit board as claimed in any one of claims 1 to 9; wherein the light emitting module comprises at least one light emitting diode.

11. An image generation unit, characterized in that: include: A display panel and a backlight source as claimed in claim 10; Wherein, the display panel includes at least two display areas, and the display areas correspond one-to-one to the light-emitting modules of the backlight source; the backlight source is configured to determine the target brightness of the corresponding light-emitting module according to the brightness information of each display area of ​​the display panel.

12. A head-up display system, characterized in that: include: The image generation unit as claimed in claim 11.

Images