LED circuit board and manufacturing method thereof

Abstract

This invention discloses an LED circuit board and its fabrication method, relating to the field of LED technology. The LED circuit board includes a central port pad and side port pads located on the same surface. The central port pad is strip-shaped extending along a first direction, and the side port pads are provided on both sides of the central port pad along its length. The circuit board includes a substrate and conductive lines disposed on the surface of the substrate. The conductive lines are connected to the central port pad and the side port pads. The conductive lines include a first line extending along the first direction and connected to the central port pad. By setting a central port pad extending along the first direction and arranging other port pads on both sides of the central port pad, the bottom space of the LED packaging unit can be reasonably utilized, allowing the first data input port pad to have a longer length, and the side port pads to have a suitable area, facilitating connection with the conductive lines and improving the strength and reliability of the connection.

Description

Technical Field

[0001] This invention relates to the field of LED technology, and in particular to an LED circuit board and its manufacturing method. Background Technology

[0002] ARGB (Addressable RGB) is a lighting technology that adds an independent control chip (control IC) to the traditional RGB (red, green, and blue) system, allowing for point-to-point programmable control of each LED chip.

[0003] In existing ARGB applications, the control chip typically requires a certain level of power supply stability. Especially in environments with significant electromagnetic interference, to ensure the normal operation of the control chip and prevent LED flickering, a filter capacitor is usually connected in parallel between the power supply and ground of each LED chip. However, existing external filter capacitor solutions have the following significant drawbacks:

[0004] 1. Occupies PCB space: External capacitors require additional solder pads, which greatly limits pixel density for narrow board designs or display panels.

[0005] 2. Limited wiring flexibility: External capacitors introduce additional wiring requirements, especially when multiple ARGB LEDs are cascaded on a single panel. Due to limited wiring space, it is difficult to complete an effective wiring layout. The current compromise is that multiple ARGB LEDs share a single filter capacitor, which greatly reduces the filtering effect.

[0006] 3. Increased manufacturing costs: External capacitors increase the costs of SMT processes and materials, and also increase the risk of poor soldering.

[0007] 4. Long anti-interference path and limited filtering effect: The external capacitor is connected to the LED through PCB traces, resulting in a long filtering circuit. The high-frequency filtering effect is affected by parasitic inductance and is not as ideal as near-end filtering.

[0008] Some LED packaging units include a control chip and an LED chip packaged together. The control chip controls the LED chip to emit light. LED packaging units typically include four exposed port pads. With technological advancements, the number of port pads in LED packaging units needs to be increased to achieve more functions; for example, the number of port pads may need to increase to five. How to arrange the positions of these port pads to ensure reliable connection with the silver paste wiring becomes a problem that needs to be solved. Furthermore, due to the small size of the LED packaging unit itself, the increased number of port pads results in a denser distribution on the bottom surface of the LED packaging unit. When the LED packaging unit is mounted onto the silver paste wiring, the downward pressure of the LED packaging unit on the silver paste wiring will squeeze the silver paste to extend to both sides, posing a risk of short circuits due to contact with other port pads, affecting the surface mount yield. If the silver paste wiring is made too thin, it is difficult to ensure overall continuity, making open circuits more likely.

[0009] Therefore, it is necessary to improve the existing technology to overcome the aforementioned defects.

[0010] The above content is only used to help understand the technical solution of this application and does not constitute an admission that the above is prior art. Summary of the Invention

[0011] The purpose of this invention is to provide an LED packaging unit to solve at least one of the above-mentioned technical problems.

[0012] To achieve the above-mentioned objectives, the present invention provides an LED circuit board, characterized in that it comprises:

[0013] An LED packaging unit includes a central port pad and side port pads located on the same surface thereon. The central port pad is strip-shaped extending along a first direction, and the side port pads are provided on both sides of the central port pad along its length.

[0014] A circuit board includes a substrate and conductive lines disposed on the surface of the substrate. The conductive lines are connected to a central port pad and a side port pad. The conductive lines include a first line body connected to the central port pad and the first line body extends along a first direction.

[0015] Furthermore, the first line is continuous and of equal width.

[0016] Furthermore, the first line includes a first portion and a second portion extending from the outside of the LED packaging unit to the bottom of the LED packaging unit. The first portion and the second portion are spaced apart along the first direction and are respectively connected to both ends of the intermediate port pad in the length direction. There is a window area between the first portion and the second portion in the first direction.

[0017] Furthermore, the first line body includes a third part connecting the first part and the second part, the width of the third part being smaller than the width of the first part and the width of the second part, and the first line body forming the window area on both sides of the width direction of the third part.

[0018] Furthermore, there is no conductive line between the first part and the second part.

[0019] Furthermore, the first line body also includes a third portion located between the first portion and the second portion, the third portion being spaced apart from the first portion and the second portion;

[0020] The width of the third part is less than or equal to the width of the first part and the second part;

[0021] The third part can be continuous or discontinuous.

[0022] Furthermore, two side port pads are provided on each side of the intermediate port pad, and the conductive line includes a second line. Each side port pad is connected to a second line. The second line is inclined relative to the first direction and the second direction. The second direction is perpendicular to the first direction. From the LED packaging unit outward, the distance between adjacent first lines and second lines gradually increases.

[0023] Furthermore, the LED packaging unit is rectangular, the side port pad is located at the corner of the LED packaging unit, and the width of the middle port pad is smaller than the width of the side port pad.

[0024] Furthermore, the LED packaging unit has a first side and a second side in a first direction. The inner end of the first part has a first distance D1 with respect to the first side, and the inner end of the second part has a second distance D2 with respect to the second side. The first distance D1 is smaller than the third distance D3 between the inner end of the port pad adjacent to the first side and the first side, and the second distance D2 is smaller than the fourth distance D4 between the port pad adjacent to the second side and the second side.

[0025] Furthermore, the LED packaging unit includes:

[0026] The control chip includes multiple ports;

[0027] The LED chip includes a first positive electrode and a first negative electrode;

[0028] The package is encapsulated outside the control chip and the LED chip, and the ports of the control chip and the first positive electrode and the first negative electrode are exposed on the same surface of the package.

[0029] The wiring layer, connected to the package, includes connection lines and an insulating layer covering the outside of the connection lines. The control chip and the LED chip are electrically connected through the connection lines. The intermediate port pad and the side port pad are both exposed outside the insulating layer and electrically connected to the control chip.

[0030] Furthermore, the control chip also includes a filter capacitor packaged within the package, and the control chip and the filter capacitor are electrically connected via the connection line.

[0031] On the other hand, the present invention proposes a method for manufacturing an LED circuit board, comprising the following steps:

[0032] S1. Provide a substrate and an LED packaging unit, the LED packaging unit including a central port pad and a side port pad located on the same surface thereon, the central port pad being a strip extending along a first direction, and the side port pad being provided on both sides of the central port pad in the length direction.

[0033] S2. A conductive paste is applied to the substrate to form an uncured conductive circuit;

[0034] S3. Place the LED packaging unit on the uncured conductive line, so that the conductive line is connected to the middle port pad and the side port pad. The conductive line includes a first line connected to the middle port pad, and the first line extends along the first direction.

[0035] Furthermore, the first line body is continuous and of equal width, and the width W of the first line body is less than the width W4 of the intermediate port pad.

[0036] Furthermore, in step S2, the uncured conductive line includes a first line connected to the intermediate port pad, the first line being continuous and having a width smaller than the width of the intermediate port pad.

[0037] Further, in step S2, the uncured conductive line includes a first line connected to the intermediate port pad. The first line includes a first part and a second part extending from the outside of the LED packaging unit to the bottom of the LED packaging unit. The first part and the second part are spaced apart along the first direction and are respectively connected to both ends of the intermediate port pad in the length direction. There is a window area between the first part and the second part in the first direction.

[0038] Furthermore, the first line body includes a third part connecting the first part and the second part, the width of the third part being smaller than the width of the first part and the width of the second part, and the first line body forming the window area on both sides of the width direction of the third part.

[0039] Furthermore, the width of the third part is less than or equal to 50% of the width of the smaller of the first part and the second part.

[0040] Furthermore, there is no conductive line between the first part and the second part.

[0041] Furthermore, the first line body also includes a third portion located between the first portion and the second portion, the third portion being spaced apart from the first portion and the second portion;

[0042] The width of the third part is less than or equal to the width of the first part and the second part;

[0043] The third part can be continuous or discontinuous.

[0044] Furthermore, two side port pads are provided on each side of the intermediate port pad. The width of the intermediate port pad is smaller than the width of the side port pads. The conductive line includes a second line body. Each side port pad is connected to a second line body. The second line body is inclined relative to the first direction and the second direction. The second direction is perpendicular to the first direction. From the LED packaging unit outward, the distance between adjacent first line bodies and second line bodies gradually increases.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] According to at least one embodiment of the present invention, an LED circuit board includes a central port pad and side port pads located on the same surface thereon. The central port pad is strip-shaped extending along a first direction, and the side port pads are provided on both sides of the central port pad along its length. The circuit board includes a substrate and conductive lines disposed on the surface of the substrate. The conductive lines are connected to the central port pad and the side port pads. Each conductive line includes a first line connected to the central port pad, and the first line extends along the first direction. By setting a central port pad extending along the first direction and arranging other port pads on both sides of the central port pad, even if the conductive lines at the bottom of the central port pad have breaks due to process issues, they can still be connected through the central port pad, preventing short circuits and improving the strength and reliability of the connection. Furthermore, the width of the conductive lines at the bottom of the central port pad can be made narrower, improving the short-circuit prevention effect. Further, the bottom space of the LED packaging unit can be reasonably utilized, allowing the first data input port pad to have a longer length and the side port pads to have a suitable area, facilitating connection with the conductive lines and improving the strength and reliability of the connection. Attached Figure Description

[0047] Figure 1 a and Figure 1 b These are cross-sectional schematic diagrams of different positions of the LED packaging unit in some embodiments of the present invention.

[0048] Figure 2 This is a schematic diagram of an LED packaging unit in some embodiments of the present invention from a top view. In the figure, the LED packaging unit does not show the packaging body, in order to show the relative positions of other components.

[0049] Figure 3 This is a schematic diagram of the control chip in some embodiments of the present invention.

[0050] Figure 4 yes Figure 2 A schematic diagram showing the location of the conductive lines in the middle.

[0051] Figure 5 This is a schematic diagram of the port pads on the bottom surface of the LED packaging unit in some embodiments of the present invention.

[0052] Figure 6 This is a cross-sectional schematic diagram of an LED circuit board according to some embodiments of the present invention.

[0053] Figure 7 This is a schematic diagram showing the connection between the LED packaging unit and the conductive circuit in some embodiments of the present invention.

[0054] Figure 8 This is a cross-sectional schematic diagram of an LED packaging unit in some embodiments of the present invention.

[0055] Figure 9 This is a schematic diagram of an LED packaging unit in some embodiments of the present invention from a top view. In the figure, the LED packaging unit does not show the packaging body, in order to show the relative positions of other components.

[0056] Figure 10 yes Figure 9 A schematic diagram showing the location of the conductive lines in the middle.

[0057] Figure 11 This is a cross-sectional schematic diagram of an LED circuit board according to some embodiments of the present invention.

[0058] Figure 12 This is a schematic diagram showing the connection between the LED packaging unit and the conductive circuit in some embodiments of the present invention.

[0059] Figure 13 This is a schematic diagram showing the connection between the LED packaging unit and the conductive circuit in some embodiments of the present invention.

[0060] Figure 14 This is a schematic diagram showing the connection between the LED packaging unit and the conductive circuit in some embodiments of the present invention.

[0061] Figure 15 This is a schematic diagram showing the connection between the LED packaging unit and the conductive circuit in some embodiments of the present invention. Detailed Implementation

[0062] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not the entire structure. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0063] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0064] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0065] Example 1: LED Packaging Unit

[0066] like Figures 1 a to 2 As shown, some embodiments of the present invention propose an LED packaging unit, which includes a control chip 1, an LED chip 2, a filter capacitor 3, a package 4, and a wiring layer 5.

[0067] The package 4 is encapsulated outside the control chip 1, LED chip 2 and filter capacitor 3. The wiring layer 5 is connected to the package 4 and is located on the lower surface 4a of the package 4.

[0068] The control chip 1 includes multiple ports 10, the LED chip 2 includes a first positive electrode 20 and a first negative electrode 21, and the filter capacitor 3 includes a second positive electrode 30 and a second negative electrode 31. The ports 10, the first positive electrode 20, the first negative electrode 21, the second positive electrode 30, and the second negative electrode 31 are all exposed on the same surface (i.e., the lower surface 4a) of the package body 4.

[0069] Wiring layer 5 is connected to package 4 and includes connection line 50 and multiple port pads electrically connected to connection line 50. Control chip 1 is electrically connected to LED chip 2 and filter capacitor 3 through connection line 50. Port pads are exposed in LED package unit and are used to connect to external circuits, providing power or transmitting signals to control chip 1 and LED chip 2.

[0070] The aforementioned filter capacitor 3 is packaged together with the LED chip 2 and the control chip 1, which has at least the following beneficial effects:

[0071] 1. Space saving and cost reduction: The filter capacitor 3 is built-in, eliminating the need to reserve capacitor positions during PCB design, thus greatly saving PCB surface space. This is particularly suitable for ultra-narrow LED strips and high-density dot matrix screens. At the same time, it reduces the SMT mounting process and material costs associated with external capacitors, simplifying the production process.

[0072] 2. Improved wiring flexibility: By eliminating the obstruction and occupation of external capacitors on PCB traces, the layout of power lines and signal lines is more free and flexible in single-sided or complex irregular board designs, effectively solving the problem of trace congestion when multiple LEDs are cascaded.

[0073] 3. Improve product reliability: The number of solder joints on the PCB board is reduced, which reduces the risk of capacitors falling off due to poor soldering of external capacitors (such as cold solder joints or bridging) or vibration or drops during use, thereby significantly improving the overall reliability of the end product.

[0074] 4. Improved anti-interference performance: The filter capacitor and the control chip are directly connected inside the package, with a very short physical distance, which greatly reduces the parasitic inductance of the power supply circuit. This makes the high-frequency filtering effect significantly better than the solution with external capacitors, effectively suppressing power supply noise and solving the problems of flickering or unstable signal transmission that are prone to occur in electromagnetic interference environments.

[0075] In some embodiments, such as Figure 3 As shown, the control chip 1 includes a power supply port 100, a ground port 101, a first data input port 102, a data output port 103, and a control port 104. The power supply port 100 is used for electrical connection to an external power supply line, and the ground port 101 is used for electrical connection to an external ground line. The control port 104 is used to control the LED chip 2 to emit light. It should be noted that a data input port indicates that data can be input through that port, but does not mean that it can only input data; for example, it can also output data. Similarly, a data output port indicates that data can be output through that port, but does not mean that it can only output data; for example, it can also input data.

[0076] Connection line 50 connects the LED chip 2, filter capacitor 3, and port pads to the corresponding port 10 of the control chip 1. In some embodiments, such as Figures 2 to 4 As shown, the connection line 50 includes a first conductive line 51 connected to the power supply port 100, a second conductive line 52 connected to the ground port 101, a third conductive line 53 connected to the first data input port 102, a fourth conductive line 54 connected to the data output port 103, and a fifth conductive line 55 connected to the control port 104. Figure 4 The cross-sectional lines in the middle show the location of the connecting line 50 for a clearer presentation.

[0077] The first positive electrode 20 and the second positive electrode 30 are simultaneously connected to the first conductive line 51, which simplifies the circuit and provides positive voltage to the control chip 1, LED chip 2 and filter capacitor 3 through the first conductive line 51.

[0078] The second negative electrode 31 is connected to the second conductive line 52 and is grounded through the second conductive line 52.

[0079] The first negative electrode 21 is connected to the fifth conductive line 55, and the fifth conductive line 55 is connected to the control port 104 of the control chip 1. The control chip 1 controls its control port 104 to be grounded or connected to a low level, so that the LED chip 2 emits light.

[0080] like Figure 2 As shown, there are three LED chips 2, and the three LED chips 2 emit light of different colors, such as red, green and blue light respectively. The control chip 1 controls the three LED chips 2 through three independent control ports 104. The first negative electrode 21 of each of the three LED chips 2 is connected to the corresponding control port 104 through a fifth conductive line 55.

[0081] In some embodiments, such as Figure 2 and Figure 5 As shown, Figure 2 The approximate locations of the pads at each port are shown by dashed lines. Figure 5 A schematic diagram showing the positions of the port pads on the bottom surface of the LED packaging unit is illustrated. Wiring layer 5 includes a power supply port pad 510 connected to the first conductive line 51, a ground port pad 511 connected to the second conductive line 52, a first data input port pad 512 connected to the third conductive line 53, and a data output port pad 513 connected to the fourth conductive line 54. The power supply port pad 510 is used to connect to an external power supply line, the ground port pad 511 is used to connect to an external ground line, the first data input port pad 512 is used to input control signals, and the control chip 1 controls the LED chip 2 to emit light according to the control signals. The data output port pad 513 is used to output signals externally.

[0082] like Figures 2 to 5 As shown, in some embodiments, the control chip 1 further includes a second data input port 105, the connection line 50 includes a sixth conductive line 56 connected to the second data input port 105, and the wiring layer 5 includes a second data input port pad 514 connected to the sixth conductive line 56. The second data input port pad 514 is used to input control signals. The control signals input to the second data input port pad 514 can serve as backup signals. When the data input to the first data input port 102 is abnormal, the LED chip 2 can be controlled to emit light according to the control signals of the second data input port pad 514, ensuring the reliability of the light emission control.

[0083] Optionally, the first data input port pad 512 extends along a first direction, and two port pads are provided on each side of the first data input port pad 512. The port pads on the same side of the first data input port pad 512 are spaced apart along the first direction. In this way, the distribution of port pads on the bottom surface of the LED packaging unit is more reasonable. At the same time, the area of ​​the first data input port pad 512 is relatively large, and when it is mounted on the circuit board, the contact area with the circuit lines (such as silver paste circuits) on the circuit board is larger, which is beneficial to improving the reliability of the connection. Figure 6 and Figure 7As shown, the conductive line 81 on the circuit board 8 has a first line body 810 extending along a first direction, and a first data input port pad 512 covering the first line body 810. The first line body 810 extends from one end of the LED packaging unit to the other end, with both ends protruding outside the LED packaging unit. Since the first data input port pad 512 is a continuous strip extending along the first direction, even if the continuous portion of the first line body 810 is broken or has an opening due to manufacturing issues, it can still conduct electricity through the first data input port pad 512 without causing an open circuit. This also allows the width of the portion of the first line body 810 corresponding to the first data input port pad 512 to be narrower, making it less likely to conduct electricity with other port pads, which helps prevent short circuits.

[0084] Optionally, the length L1 of the first data input port pad 512 is not less than 80% of the length L2 of the LED packaging unit along the first direction, to enhance the reliability of the electrical connection between the first data input port pad 512 and the circuit on the circuit board. The first line 810 can be made narrower and the part with lower process requirements can be longer, which is beneficial to reliably prevent open circuit and short circuit problems. Further optionally, the length L1 of the first data input port pad 512 is not less than 90% of the length L2 of the LED packaging unit along the first direction. Even more optionally, the first data input port pad 512 does not directly contact the two sides of the LED packaging unit in the length direction. For example, the distance D5 between it and the two sides of the LED packaging unit is not less than 50μm, to prevent the first data input port pad 512 from being cut during the cutting and granulation process.

[0085] In some embodiments, such as Figure 1 a and Figure 1 b As shown, wiring layer 5 also includes an insulating layer 58 covering the outside of the connection lines 50, and the insulating layer 58 also covers the surface of the package body 4. Multiple port pads are exposed on the same surface of the insulating layer 58 and are connected to the connection lines 50 via metallized vias 57. Figure 1 b The diagram shows a schematic of the third conductive line 53 connected to the first data input port pad 512 via a metallized via 57. Since the port pads are located on the same side of the LED package unit, the LED package unit is more easily connected to external circuitry.

[0086] like Figure 2 As shown, three LED chips 2 are spaced apart along the second direction and located on the same side of the control chip 1 along the first direction. The second direction is perpendicular to the first direction. When the LED packaging unit is rectangular, the first direction and the second direction can correspond to the extension directions of two adjacent sides of the LED packaging unit, for example, one of which is the length direction of the LED packaging unit and the other is the width direction of the LED packaging unit.

[0087] In some embodiments, the LED chip 2 is located between the control chip 1 and the filter capacitor 3, such as... Figure 2 As shown, the control chip 1, LED chip 2 and filter capacitor 3 are arranged sequentially and at intervals along the first direction, so that the LED chip 2 is close to the geometric center of the package body 4, and the layout is more balanced. The central design of LED chip 2 not only ensures the symmetrical uniformity of the emitted light pattern, but also facilitates the alignment and design of subsequent secondary optical components such as lenses and light guides, and avoids optical loss or light spot shift caused by light source bias.

[0088] Figure 2 and Figure 3 In the illustrated embodiment, some (specifically two) control ports 104 are located on the side closer to the LED chip 2, and some (specifically one) control ports 104 are located on the side farther from the LED chip 2. In other embodiments, all control ports 104 of the control chip 1 may be located on the side closer to the LED chip 2. The first positive electrode 20 of the LED chip 2 is disposed near the filter capacitor 3, and the first negative electrode 21 is disposed near the control chip 1. This makes the length of the fifth conductive line 55 connecting the first negative electrode 21 and the control chip 1 shorter, and the first conductive line 51 is more convenient to connect the first positive electrode 20 and the second positive electrode 30 simultaneously, facilitating wiring. Optionally, the LED chip 2 is disposed along a first direction, and its first positive electrode 20 and first negative electrode 21 are arranged at intervals along the first direction.

[0089] The LED packaging unit has a middle surface 40, which is a plane perpendicular to the second direction and passes through the center of the LED packaging unit. Optionally, the control chip 1, the filter capacitor 3, and the LED chip 2 located in the middle are all arranged close to the middle surface 40. Further optionally, the middle surface 40 passes through the control chip 1, the filter capacitor 3, and the LED chip 2 located in the middle, so that the lengths of the first conductive line 51 and the second conductive line 52 are closer. Figure 2 and Figure 3In the illustrated embodiment, the ground port 101 and power supply port 100 of the control chip 1 are respectively located on the same side (upper side in the figure) of the control chip 1 in the second direction, and the ground port 101 and the second negative electrode 31 of the filter capacitor 3 are located on the same side (upper side in the figure) to facilitate wiring. Optionally, the filter capacitor 3 is arranged along the second direction, and its second positive electrode 30 and second negative electrode 31 are arranged at intervals along the second direction. In other embodiments, the ground port 101 and power supply port 100 of the control chip 1 may be located on opposite sides (upper and lower sides in the figure) of the control chip 1 in the second direction, and the ground port 101 and the second negative electrode 31 of the filter capacitor 3 are located on the same side (upper side in the figure), and the power supply port 100 and the second positive electrode 30 of the filter capacitor 3 are located on the same side (lower side in the figure) to shorten the line and facilitate wiring. The filter capacitor 3 is arranged along the second direction, and its second positive electrode 30 and second negative electrode 31 are arranged at intervals along the second direction.

[0090] In some embodiments, the control chip 1 and the filter capacitor 3 are located on the same side of the LED chip 2, such as... Figures 8 to 10 As shown, the control chip 1 and the filter capacitor 3 are spaced apart along the second direction, and the control chip 1 and the filter capacitor 3 are spaced apart from the LED chip 2 along the first direction. It is understood that the LED chip 2 will generate heat during operation, forming a heat concentration area (the center of which is roughly located at the middle of the LED chip 2). The capacitance value of the filter capacitor 3 will change with temperature (generally, the capacitance value decreases or drifts with increasing temperature, which may also lead to an increase in ESR (equivalent series resistance) and leakage current, resulting in decreased decoupling capability, poorer filtering effect, and reduced service life). Placing the filter capacitor 3 on one side of the control chip 1 keeps it away from the heat concentration area, ensuring the reliability of the filter capacitor 3. At the same time, this arrangement makes the overall structure compact, facilitates wiring, and is beneficial for miniaturization. Optionally, the filter capacitor 3 can be located directly above the port pad (the second data input port pad 514 in the figure) to dissipate heat through the port pad, further ensuring the reliability of the filter capacitor 3. Optionally, the filter capacitor 3 can be located on the same side as the power supply port 100 or the ground port 101 of the control chip 1. Figure 9 In the illustrated embodiment, a portion of the filter capacitor 3 is located directly above the port pad. Optionally, more than half of the filter capacitor 3 is located directly above the port pad. More preferably, the entire filter capacitor 3 is located directly above the port pad to further improve heat dissipation.

[0091] like Figure 2 and Figure 3As shown, the power supply port 100 and the second data input port 105 are located on both sides of the control chip 1 in the second direction (the upper and lower sides in the figure), respectively. The first data input port 102 is located between the two control ports 104, and all three are located on the same side of the control chip 1 (the right side in the figure). In this way, the first data input port pad 512 is located in the middle of the LED packaging unit, which makes it easier to set it to extend along the first direction. The third conductive line 53 extends towards the middle of the LED packaging unit, so that the metallized via 57 connecting the first data input port pad 512 is close to the middle of the first data input port pad 512. The power supply port pad 510, the ground port pad 511, the data output port pad 513, and the second data input port pad 514 are located at the four corners of the LED packaging unit, respectively. The power supply port pad 510 and the data output port pad 513 are located on the same side of the first data input port pad 512 (the lower side in the figure), and the ground port pad 511 and the second data input port pad 514 are located on the same side of the first data input port pad 514 (the upper side in the figure).

[0092] It is understandable that the aforementioned LED packaging unit can be fabricated into an LED circuit board, for example, as shown in the image. Figure 6 and Figure 7 As shown, the LED packaging unit can be mounted on the circuit board 8. The circuit board 8 includes a substrate 80 and conductive lines 81 disposed on the surface of the substrate 80. The conductive lines 81 are connected to the port pads.

[0093] Example 2: Method for preparing LED circuit boards

[0094] Some embodiments of the present invention provide a method for manufacturing an LED circuit board, which includes the following steps:

[0095] S1. Provide a substrate 80 and an LED packaging unit 9. The substrate 80 can be a rigid board or a flexible board. The LED packaging unit 9 includes a middle port pad and side port pads. The middle port pad is a strip extending along a first direction. Side port pads are provided on both sides of the length direction of the middle port pad. It can be understood that the length direction of the middle port pad is consistent with the first direction, and the width direction is consistent with the second direction. LED packaging unit 9 can be the LED packaging unit described above, or it can be an LED packaging unit with other structures. For ease of description, the LED packaging unit described above will be used as an example below. In this case, the middle port pad is the first data input port pad 512 described above. The power supply port pad 510, the ground port pad 511, the data output port pad 513, and the second data input port pad 514 are all side-mounted port pads. The ground port pad 511 and the second data input port pad 514 are located on the same side of the first data input port pad 512 (the upper side in the figure). The other two port pads are located on the same side of the first data input port pad 512 (the lower side in the figure).

[0096] S2. A conductive paste is applied to the substrate 80 to form uncured conductive lines 81. The conductive paste can be applied to the substrate 80 by printing, for example, silver paste. For ease of description, the substrate 80 with the conductive lines 81 is referred to as a circuit board 8.

[0097] S3. Place the LED packaging unit 9 on the uncured conductive line 81, so that the conductive line 81 is connected to the middle port pad and the side port pad. The conductive line 81 includes a first line body 810 connected to the middle port pad, and the first line body 810 extends along a first direction.

[0098] As described above, by setting an intermediate port pad extending along the first direction and arranging other port pads on both sides of the intermediate port pad, the width of the conductive line (i.e., the first line body 810) corresponding to the intermediate port pad can be narrowed. This effectively reduces the risk of short circuits caused by the conductive paste extending outward under pressure. Even if there is a break in the conductive line corresponding to the intermediate port pad due to process issues, conduction can still be achieved through the intermediate port pad, preventing open circuits. Furthermore, the bottom space of the LED packaging unit 9 can be reasonably utilized, allowing the first data input port pad 512 to have a longer length, and the side-mounted port pads to have a suitable area, facilitating connection with the conductive line 81 and improving the strength and reliability of the connection.

[0099] It should be pointed out that, Figure 7 , Figures 12 to 15The location of the port pads is indicated by a dashed box, and the location of the conductive line 81 set in step S2 is shown by a cross-section. It can be understood that the conductive line 81 in step S2 is not cured.

[0100] Optionally, the width W4 of the middle port pad is smaller than the width W5 of the side port pad, so that both the middle port pad and the side port pad have a relatively large area, thereby improving the reliability of the connection with the conductive line 81.

[0101] In some embodiments, such as Figure 6 and Figure 7 As shown, the first line 810 is continuous and of equal width, extending in a strip shape along the first direction, so as to increase the contact area between the intermediate port pad and the first line 810, thereby improving the reliability of the electrical connection. Optionally, the width W of the first line 810 is smaller than the width W4 of the intermediate port pad. In this way, when the LED packaging unit 9 is connected to the first line 810 (for example, when the LED packaging unit 9 is fixed by SMT), the LED packaging unit 9 applies pressure to the conductive paste. After the conductive paste of the first line 810 is stretched under pressure, the area exceeding the intermediate port pad is smaller, making it less likely to contact the side port pad, thus improving reliability.

[0102] In some embodiments, such as Figure 11 and Figure 12 As shown, the first line body 810 includes a first portion 8100 and a second portion 8101 extending from the outside of the LED packaging unit 9 to the bottom of the LED packaging unit 9. The first portion 8100 and the second portion 8101 are spaced apart along a first direction and are respectively connected to both ends of the intermediate port pad in the length direction. Both the first portion 8100 and the second portion 8101 are strip-shaped extending along the first direction. There is a window area 8104 between the first portion 8100 and the second portion 8101 in the first direction. The window area 8104 does not have conductive lines 81, or in other words, it does not have conductive material, such as an exposed substrate.

[0103] When the LED packaging unit 9 is connected to the first line 810, the LED packaging unit 9 applies pressure to the conductive paste. Because it has a window area 8104 in the first direction, the conductive paste can extend to both sides of the first line 810 in the width direction and to the window area 8104. Compared to the traditional structure that can only extend along the width direction, this reduces the extension distance in the width direction, making it less likely for the conductive paste to contact the side port pads, thus improving yield. Furthermore, because the extension distance of the conductive paste along the width direction is reduced, the spacing between the side port pads and the middle port pads along the second direction can be appropriately reduced, increasing the area of ​​the port pads and facilitating a more reliable connection with the conductive line 81.

[0104] There are several ways to create a blank area 8104. The following are some feasible solutions.

[0105] In some embodiments, such as Figure 13 As shown, the first line body 810 includes a third part 8102 connecting the first part 8100 and the second part 8101. The width W1 of the third part 8102 is smaller than the width W2 of the first part 8100 and the width W3 of the second part 8101. It is understood that the widths of the first part 8100 and the second part 8101 are essentially the same, although they can also be different. A window area 8104 is formed on both sides of the width direction of the third part 8102. In this design, the contact length and contact area between the first line body 810 and the intermediate port pad are relatively large, resulting in better connection reliability and robustness.

[0106] Optionally, the width W1 of the third portion 8102 is less than or equal to 50% of the width of the smaller of the first portion 8100 and the second portion 8101, so that the conductive paste of the first line 810 can reliably extend toward the window area 8104. Obviously, when the widths of the first portion 8100 and the second portion 8101 are the same, the width of the smaller one is consistent with the widths of both.

[0107] In other embodiments, such as Figure 11 and Figure 12 As shown, there is no conductive line between the first part 8100 and the second part 8101; the area between them is, for example, an exposed substrate surface. This creates a window region 8104 between the first part 8100 and the second part 8101. This window region 8104 has the largest area, resulting in less resistance to the conductive paste of the first line 810 extending towards the window region 8104. Clearly, even if there are gaps or cracks in the portions of the first part 8100 and the second part 8101 corresponding to the intermediate port pads due to process issues, conductivity can still be achieved through the intermediate port pads, preventing open circuits.

[0108] In some other embodiments, such as Figure 14 and Figure 15 As shown, the first wire 810 also includes a third portion 8102 located between the first portion 8100 and the second portion 8101. In this embodiment, the third portion 8102 is spaced apart from the first portion 8100 and the second portion 8101 and is not connected to them. At this time, the gap between the third portion 8102 and the first portion 8100 and the second portion 8101 forms a window area 8104. The conductive paste of the first wire 810 can reliably extend towards the window area 8104. At the same time, the third portion 8102 can also connect the LED packaging unit 9 and the substrate 80, improving the connection strength.

[0109] Optionally, the width W1 of the third portion 8102 is less than or equal to the width W2 of the first portion 8100 and the width W3 of the second portion 8101. More optionally, the width W1 of the third portion 8102 is less than or equal to 50% of the width of the smaller of the widths of the first portion 8100 and the second portion 8101. This reduces the extent to which the conductive paste of the third portion 8102 extends towards the side port pads under pressure, further improving reliability.

[0110] Optionally, the third part 8102 is continuous, such as... Figure 14 As shown, only a section of conductive paste is provided between the first part 8100 and the second part 8101, which can increase the connection area with the LED packaging unit 9. Optionally, the third part 8102 is a strip extending along the first direction. In other embodiments, the third part 8102 can also be discontinuous, such as... Figure 15 As shown, multiple sections of conductive paste are provided between the first part 8100 and the second part 8101. These multiple sections of conductive paste constitute the third part 8102. Since the third part 8102 is discontinuous, the multiple sections of conductive paste can extend along the first direction after being compressed, which helps to reduce the extent of its extension along the second direction, further ensuring the yield rate and reducing the risk of short circuit.

[0111] It is understandable that, regardless of whether the first line 810 is continuous or includes two or more discontinuous sections, its whole still extends along the first direction.

[0112] In some embodiments, two side port pads are provided on each side of the central port pad, such as... Figure 12 As shown, one side of the middle port pad (the upper side in the figure) is provided with a ground port pad 511 and a second data input port pad 514, and the other side of the middle port pad (the lower side in the figure) is provided with a data output port pad 513 and a power supply port pad 510. The conductive line 81 includes a second line body 811, and each side port pad is connected to a second line body 811 to connect different circuits through independent second line bodies 811. The LED packaging unit 9 is rectangular, and the side port pads are located at the corners of the LED packaging unit 9.

[0113] The second trace 811 is inclined relative to the first and second directions. From the LED packaging unit 9 outwards, the distance between adjacent first traces 810 and second traces 811 gradually increases. This increases the safety spacing between the traces, making the sides of the traces more open and preventing the conductive paste from spreading outwards under pressure and causing short circuits. Furthermore, when the substrate 80 is a flexible substrate, the inclined traces can alleviate the mechanical stress on the substrate. Horizontal or vertical traces are prone to stress concentration when bent, leading to breakage. Inclined traces can disperse stress when the substrate bends or twists, reducing the risk of brittle fracture. Optionally, the angle α between the second trace 811 and the first direction is 45° to further ensure the effect.

[0114] Optional, such as Figure 12 As shown, the LED packaging unit 9 has a first side 90 and a second side 91 in a first direction. A first distance D1 exists between the inner end of the first portion 8100 and the first side 90, and a second distance D2 exists between the inner end of the second portion 8101 and the second side 91. The first distance D1 is smaller than the third distance D3 between the inner end of the port pads adjacent to the first side 90 (ground port pad 511 and power supply port pad 510 in the figure) and the first side 90 (when the inner end of the ground port pad 511 and power supply port pad 510 is...). When the spacing between the first side 90s is different, the smaller value is taken as the third spacing D3. The second spacing D2 is smaller than the fourth spacing D4 between the inner end of the port pads adjacent to the second side 91 (data output port pad 513 and data input port pad 514 in the figure) and the second side 91 (when the spacing between the inner end of the data output port pad 513 and the second data input port pad 514 and the second side 91 is different, the smaller value is taken as the fourth spacing D4). The inner end refers to the end extending to the bottom of the LED packaging unit 9. Since the first spacing D1 is smaller than the third spacing D3 and the second spacing D2 is smaller than the fourth spacing D4, the risk of the conductive paste corresponding to each port pad contacting under pressure can be further reduced.

[0115] Alternatively, the second line 811 corresponds to the corner of the LED packaging unit 9 (through the intersection of two adjacent sides), so that the spacing between the first line 810 and the second line 811 in the second direction is larger, which can further reduce the risk of the conductive paste of the first line 810 and the second line 811 coming into contact under pressure.

[0116] As described above, the LED packaging unit 9 can be the LED packaging unit described above, which encapsulates the filter capacitor 3. In other embodiments, the LED packaging unit 9 can also be an LED packaging unit with other structures, which only need to have a middle port pad and a side port pad. For example, it may not have the filter capacitor 3, but the filter capacitor 3 can be disposed on the substrate 80 by means of bonding.

[0117] Example 3: LED Circuit Board

[0118] like Figure 6 , Figure 7 , Figures 11 to 15 As shown, some embodiments of the present invention provide an LED circuit board, which includes an LED packaging unit 9 and a circuit board 8 for mounting the LED packaging unit 9.

[0119] The LED circuit board can be prepared by the LED circuit board preparation method described in Example 2 above.

[0120] Understandable Figure 7 , Figures 12 to 15 The mid-section line shows the initial position of the conductive paste when it is not under pressure. After being under pressure, the conductive paste will extend outward. After extension, the position of the conductive paste may change, so that the final solidified conductive line 81 is different from the shape shown in the figure.

[0121] For example, Figure 7 , Figures 12 to 15 In the illustrated embodiment, the width W4 of the intermediate port pad is greater than the width W of the uncured first line 810. After the LED packaging unit 9 is installed on the first line 810, the final cured width W of the first line 810 may still be smaller than the width W4 of the intermediate port pad, or it may be greater than or equal to the width W4 of the intermediate port pad. Optionally, the final cured width W of the first line 810 may be less than or equal to the width W4 of the intermediate port pad to reliably prevent short circuits.

[0122] For example, Figure 12 In the illustrated embodiment, the width of the first part 8100 and the second part 8101 after curing will increase, and they will also extend a distance along the empty area 8104 in the first direction. Optionally, after extension (curing), there is still an empty area 8104 between the first part 8100 and the second part 8101, and the first spacing D1 is still smaller than the third spacing D3, and the second spacing D2 is still smaller than the fourth spacing D4.

[0123] For example, Figure 13In the illustrated embodiment, the widths of the first portion 8100 and the second portion 8101 after curing will increase, and the width of the third portion 8102 will also increase. The width W1 of the third portion 8101 may still be smaller than the width W4 of the intermediate port pad, or it may be greater than or equal to the width W4 of the intermediate port pad. Optionally, the width W1 of the third portion 8101 after curing may still be smaller than the width W4 of the intermediate port pad.

[0124] For example, Figure 14 and Figure 15 In the illustrated embodiment, the widths of the cured first portion 8100 and second portion 8101 increase, as does the width of the third portion 8102. Simultaneously, the first portion 8100, second portion 8101, and third portion 8102 extend along the first direction to the empty area 8104. The third portion 8102 may or may not contact the first portion 8100 and second portion 8101; even when not in contact, the empty area 8104 will still exist. It is understood that... Figure 15 In the middle, different parts of the third part 8102 may or may not be in contact with each other. When they are not in contact, there will still be a gap area 8104. Optionally, by controlling the length L3 of the gap in the first line 810 in the first direction, the gap is filled when the conductive paste of the first line 810 is compressed, forming a continuous first line 810, so as to improve the conductivity and connection reliability.

[0125] Since the LED circuit board can be prepared by the LED circuit board preparation method in Example 2, other structural features of the LED circuit board can also be referred to the above description, and will not be repeated here.

[0126] It should be noted that, in the absence of conflict, the various embodiments described herein can be combined with each other to obtain more implementation schemes.

[0127] The above are merely specific embodiments of the present invention, and any improvements made based on the concept of the present invention shall be considered within the scope of protection of the present invention.

Claims

1. An LED circuit board, characterized in that, include: The LED packaging unit (9) includes a central port pad and side port pads located on the same surface thereon. The central port pad is strip-shaped extending along a first direction, and the side port pads are provided on both sides of the central port pad along its length. The circuit board (8) includes a substrate (80) and conductive lines (81) disposed on the surface of the substrate (80). The conductive lines (81) are connected to the intermediate port pad and the side port pad. The conductive lines (81) include a first line body (810) connected to the intermediate port pad. The first line body (810) extends along the first direction.

2. The LED circuit board as described in claim 1, characterized in that, The first line body (810) is continuous and of equal width.

3. The LED circuit board as described in claim 1, characterized in that, The conductive line (81) includes a first part (8100) and a second part (8101) extending from the outside of the LED packaging unit (9) to the bottom of the LED packaging unit (9). The first part (8100) and the second part (8101) are spaced apart along the first direction and are respectively connected to both ends of the intermediate port pad in the length direction. There is a window area (8104) between the first part (8100) and the second part (8101) in the first direction.

4. The LED circuit board as described in claim 3, characterized in that, The first line body (810) includes a third part (8102) connecting the first part (8100) and the second part (8101), the width of the third part (8102) being smaller than the width of the first part (8100) and the width of the second part (8101), and the first line body (810) forming the window area (8104) on both sides of the width direction of the third part (8102).

5. The LED circuit board as described in claim 3, characterized in that, There is no conductive line between the first part (8100) and the second part (8101).

6. The LED circuit board as described in claim 3, characterized in that, The first line body (810) further includes a third portion (8102) located between the first portion (8100) and the second portion (8101), the third portion (8102) being spaced apart from the first portion (8100) and the second portion (8101); The width of the third part (8102) is less than or equal to the width of the first part (8100) and the second part (8101); The third part (8102) can be continuous or discontinuous.

7. The LED circuit board as described in claim 3, characterized in that, Two side port pads are provided on each side of the middle port pad. The conductive line (81) includes a second line body (811). Each side port pad is connected to a second line body (811). The second line body (811) is inclined relative to the first direction and the second direction. The second direction is perpendicular to the first direction. From the LED packaging unit (9) outward, the distance between adjacent first line bodies (810) and second line bodies (811) gradually increases.

8. The LED circuit board as described in claim 7, characterized in that, The LED packaging unit (9) is rectangular, and the side port pads are located at the corners of the LED packaging unit; The width of the intermediate port pad is smaller than the width of the side port pad.

9. The LED circuit board as described in claim 7, characterized in that, The LED packaging unit (9) has a first side (90) and a second side (91) in a first direction. The inner end of the first part (8100) and the first side (90) have a first distance D1, and the inner end of the second part (8101) and the second side (91) have a second distance D2. The first distance D1 is smaller than the third distance D3 between the inner end of the port pad adjacent to the first side (90) and the first side (90), and the second distance D2 is smaller than the fourth distance D4 between the port pad adjacent to the second side (91) and the second side (91).

10. The LED circuit board according to any one of claims 1 to 9, characterized in that, The LED packaging unit (9) includes: The control chip (1) includes multiple ports (10); LED chip (2) includes a first positive electrode (20) and a first negative electrode (21). The package (4) is encapsulated outside the control chip (1) and the LED chip (2), and the port (10) of the control chip (1), the first positive electrode (20), and the first negative electrode (21) are exposed on the same surface of the package (4). The wiring layer (5) is connected to the package (4) and includes a connection line (50) and an insulating layer (58) covering the outside of the connection line (50). The control chip (1) and the LED chip (2) are electrically connected through the connection line (50). The middle port pad and the side port pad are exposed outside the insulating layer (58) and electrically connected to the control chip (1).

11. The LED circuit board as described in claim 10, characterized in that, The control chip (1) also includes a filter capacitor (3) encapsulated in the package (4), and the control chip (1) and the filter capacitor (3) are electrically connected through the connection line (50).

12. A method for manufacturing an LED circuit board, characterized in that, Includes the following steps: S1. Provide a substrate (80) and an LED packaging unit (9), the LED packaging unit (9) including a middle port pad and a side port pad located on the same surface thereon, the middle port pad being a strip extending along a first direction, and the side port pad being provided on both sides of the length direction of the middle port pad. S2. A conductive paste is applied to the substrate (80) to form an uncured conductive line (81). S3. Place the LED packaging unit (9) on the uncured conductive line (81) so that the conductive line (81) is connected to the middle port pad and the side port pad. The conductive line (81) includes a first line (810) connected to the middle port pad, and the first line (810) extends along the first direction.

13. The method for preparing an LED circuit board as described in claim 12, characterized in that, The first line body (810) is continuous and of equal width, and the width W of the first line body (810) is less than the width W4 of the intermediate port pad.

14. The method for preparing an LED circuit board as described in claim 12, characterized in that, In step S2, the uncured conductive line (81) includes a first line (810) connected to the intermediate port pad. The first line (810) is continuous and its width is smaller than the width of the intermediate port pad.

15. The method for preparing an LED circuit board as described in claim 12, characterized in that, In step S2, the uncured conductive line (81) includes a first line (810) connected to the intermediate port pad. The first line (810) includes a first part (8100) and a second part (8101) extending from the outside of the LED packaging unit (9) to the bottom of the LED packaging unit (9). The first part (8100) and the second part (8101) are spaced apart along the first direction and are respectively connected to both ends of the intermediate port pad in the length direction. There is a window area (8104) between the first part (8100) and the second part (8101) in the first direction.

16. The LED circuit board as described in claim 15, characterized in that, The first line body (810) includes a third part (8102) connecting the first part (8100) and the second part (8101), the width of the third part (8102) being smaller than the width of the first part (8100) and the width of the second part (8101), and the first line body (810) forming the window area (8104) on both sides of the width direction of the third part (8102).

17. The LED circuit board as described in claim 16, characterized in that, The width of the third part (8102) is less than or equal to 50% of the width of the smaller of the widths of the first part (8100) and the second part (8101).

18. The LED circuit board as described in claim 15, characterized in that, There is no conductive line between the first part (8100) and the second part (8101).

19. The LED circuit board as described in claim 15, characterized in that, The first line body (810) further includes a third portion (8102) located between the first portion (8100) and the second portion (8101), the third portion (8102) being spaced apart from the first portion (8100) and the second portion (8101); The width of the third part (8102) is less than or equal to the width of the first part (8100) and the second part (8101); The third part (8102) can be continuous or discontinuous.

20. The LED circuit board according to any one of claims 12 to 19, characterized in that, Two side port pads are provided on each side of the middle port pad. The width of the middle port pad is smaller than the width of the side port pads. The conductive line (81) includes a second line body (811). Each side port pad is connected to a second line body (811). The second line body (811) is inclined relative to the first direction and the second direction. The second direction is perpendicular to the first direction. From the LED packaging unit (9) outward, the distance between adjacent first line bodies (810) and second line bodies (811) gradually increases.

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