Circuit board and electronic equipment
By setting a solder resist layer on the substrate of the circuit board and a hollow groove, the problems of substrate deformation and packaging layer warping are solved, and better welding quality and sealing effect are achieved.
Patent Information
- Application Number
- CN202422000254.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-19
- Publication Date
- 2025-06-17
- Estimated Expiration
- 2034-08-19
AI Technical Summary
During the production process of circuit boards, the substrate is prone to deform due to thermal expansion, and the packaging layer has fewer contact surfaces with the substrate, poor bonding effect, which easily causes warping, affecting the quality of the circuit board.
A circuit board is designed, by providing a solder resist layer on the substrate and providing a window area on the solder resist layer to expose the pads, and at the same time, a plurality of hollow grooves are provided on the outside of the solder resist layer, so that the conductive part is located below the solder resist layer between the hollow grooves. In the subsequent reflow soldering process, this design can quickly dissipate heat to avoid substrate deformation, and enhance the bonding force between the packaging layer and the substrate, thereby improving the sealing effect.
The problem of substrate deformation due to thermal expansion is effectively avoided, and the combination between the packaging layer and the substrate is enhanced through hollow design, and the quality of the circuit board and the airtightness of the lamp beads are improved.
Smart Images
Figure CN222996744U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of LEDs, and particularly relates to a circuit board and an electronic device. Background Art
[0002] A PCB (Printed Circuit Board), whose Chinese name is printed circuit board and is also called printed wiring board, is an important electronic component, a support for electronic components, and a carrier for electrical connection of electronic components. Solder mask is an extremely important process in the PCB manufacturing process. Its main function is to cover the etched circuit pattern with solder mask ink by screen printing, covering all parts that do not need to be welded with components to prevent the problem of electrical interconnection and short circuit caused by tinning during the component welding process.
[0003] In flip-chip display Mini LEDs, after the solder mask ink is set, windows are usually opened on the solder mask ink to expose the pad structure, and a packaging layer is laid on it.
[0004] However, in subsequent processes, due to the different materials of the substrate, the solder mask ink layer, and the packaging layer, and thus the inconsistent coefficient of thermal expansion, in the subsequent reflow soldering process, the substrate is easily deformed by heat, affecting the welding quality and the operation of subsequent processes. In addition, the contact surface between the packaging layer and the substrate is small, and the bonding effect between the packaging layer and the solder mask layer is poor, easily causing warping, reducing the airtightness, and thus affecting the quality of the circuit board. Summary of the Utility Model
[0005] Based on this, the purpose of the utility model is to provide a circuit board and an electronic device, aiming to solve the problem that the substrate is easily deformed and the packaging layer is easily warped during the production process of the existing circuit board, affecting the quality of the circuit board.
[0006] The circuit board proposed by the utility model includes a substrate, a copper foil layer provided on the substrate, a solder mask layer provided on the copper foil layer, and a packaging layer provided on the solder mask layer. The copper foil layer includes a plurality of pads and a plurality of conductive parts extending outward from the pads. A window area is provided in the middle of the solder mask layer to expose the pads. A plurality of hollow grooves are provided outside the solder mask layer. The conductive parts are located below the solder mask layer between the hollow grooves.
[0007] The above-mentioned circuit board has a solder mask layer provided on the substrate. In addition to the window areas provided on the solder mask layer for exposing the pads, a plurality of hollow grooves are also provided, such that the conductive portions are located below the solder mask layer between the hollow grooves. Since a plurality of hollow grooves are added to the solder mask layer, during the subsequent reflow soldering process, the heat received by the substrate can be quickly dissipated, thereby avoiding the situation of the substrate being deformed by heat. In addition, due to the hollow design, the contact surfaces between the encapsulation layer and the solder mask layer and the substrate are uneven, thereby increasing the bonding force between them and preventing the encapsulation layer from easily detaching. Moreover, since the encapsulation layer is in direct contact with the substrate in some areas without being blocked by the solder mask layer, the bonding effect between the encapsulation layer and the substrate is better, thereby enhancing the local bonding force and improving the sealing effect here, and thus improving the airtightness of the lamp bead. Therefore, the present invention solves the problems in the prior art that the substrate is prone to deformation and the encapsulation layer is prone to warping during the production process of the circuit board, which affects the quality of the circuit board.
[0008] In addition, the circuit board proposed according to the present invention may further have the following additional technical features:
[0009] Preferably, a plurality of bottom pads and a bottom solder mask layer are provided at the bottom of the substrate, and the bottom solder mask layer is provided between the plurality of bottom pads to separate the bottom pads from each other.
[0010] Preferably, four bottom pads are provided at the bottom of the substrate and are distributed at the four corners of the bottom of the substrate. The bottom solder mask layer is in a cross shape to separate the four bottom pads from each other, and an identification portion for distinguishing the electrode directions of the bottom pads is further provided on the bottom solder mask layer.
[0011] Preferably, the distance between the edge of the hollow groove and the outer edge of the conductive portion is greater than a preset value.
[0012] Preferably, via holes are provided on the substrate, and connectors are provided in the via holes to connect the plurality of conductive portions to the plurality of bottom pads respectively.
[0013] Preferably, a plurality of grooves are evenly distributed on the substrate, and the plurality of grooves are respectively located at the bottoms of the plurality of hollow grooves.
[0014] Preferably, the cross-sectional area of the groove gradually increases from the side close to the solder mask layer to the other side.
[0015] Preferably, the cross-sectional shape of the groove is a T shape or a trapezoid.
[0016] Preferably, the multi-ends of the solder mask layer are flush with the substrate to make each of the hollow grooves independent.
[0017] In addition, the present invention further provides an electronic device, and the electronic device includes the above-mentioned circuit board. Brief Description of the Drawings
[0018] Figure 1 It is a schematic structural diagram of a circuit board proposed in an embodiment of the present utility model;
[0019] Figure 2 It is a bottom view of the circuit board proposed in an embodiment of the present utility model;
[0020] Figure 3 is Figure 1 a schematic structural diagram after hiding the encapsulation layer;
[0021] Figure 4 is Figure 3 a schematic structural diagram after hiding the copper foil layer.
[0022] Main element symbol description:
[0023] substrate 10 copper foil layer 20 solder mask layer 30 encapsulation layer 40 pad 21 conductive part 22 windowed area 31 hollowed-out groove 32 bottom pad 50 bottom solder mask layer 60 marking part 70 via hole 11 groove 12
[0024] The following specific embodiments will further illustrate the present utility model in conjunction with the above-mentioned drawings. Specific Embodiments
[0025] To facilitate the understanding of the present utility model, the present utility model will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present utility model are given in the drawings. However, the present utility model can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present utility model more thorough and comprehensive.
[0026] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration.
[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present utility model belongs. The terms used herein in the specification of the present utility model are only for the purpose of describing specific embodiments and are not intended to limit the present utility model. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.
[0028] Please refer to Figures 1 to 4, which is a circuit board in an embodiment of the utility model, includes a substrate 10, a copper foil layer 20 disposed on the substrate 10, a solder resist layer 30 disposed on the copper foil layer 20, and a packaging layer 40 disposed on the solder resist layer 30, wherein:
[0029] The copper foil layer 20 includes a plurality of solder pads 21 and a plurality of conductive portions 22 extending outward from the solder pads 21. A window area 31 is provided in the middle of the solder resist layer 30 to expose the solder pads 21 outside the solder resist layer 30. A plurality of hollow grooves 32 are provided on the outside of the solder resist layer 30. The conductive portions 22 are located below the solder resist layer 30 between the hollow grooves 32.
[0030] It can be understood that by setting a solder resist layer 30 on the substrate 10 and setting a window area 31 on the solder resist layer 30 for exposing the bare pad 21, a plurality of hollow grooves 32 are also set, so that the conductive part 22 is located below the solder resist layer 30 between the hollow grooves 32. Since a plurality of hollow grooves 32 are added to the solder resist layer 30, the heat received by the substrate 10 can be quickly dissipated during the subsequent reflow soldering process, thereby avoiding the condition where the substrate 10 is deformed by heat. In addition, due to the hollow design, the contact surface between the packaging layer 40 and the solder resist layer 30 and the substrate 10 is uneven, thereby increasing the direct bonding force between each other, so that the packaging layer 40 will not be easily detached. In addition, since the packaging layer 40 is in direct contact with the substrate 10 in some areas without the obstruction of the solder resist layer 30, the bonding effect between the packaging layer 40 and the substrate 10 is better, thereby enhancing the local bonding force and improving the sealing effect here, thereby improving the airtightness of the lamp bead. Therefore, the utility model solves the problem in the prior art that the substrate 10 is easily deformed and the packaging layer 40 is easily warped during the production process of the circuit board, which affects the quality of the circuit board.
[0031] Specifically, a plurality of bottom pads 50 and a bottom solder resist layer 60 are provided at the bottom of the substrate 10, and the bottom solder resist layer 60 is provided between the plurality of bottom pads 50 to separate the bottom pads 50 from each other. In addition, in a specific implementation, a bottom pad 50 is also provided on the back of the substrate 10 for conducting a conductive connection, and the bottom pads 50 are separated from each other by providing the bottom solder resist layer 60, thereby preventing the bottom pads 50 from being tinned together, making the circuit board scrapped.
[0032] In addition, four bottom pads 50 are provided at the bottom of the substrate 10 and are distributed at the four corners of the bottom of the substrate 10. The bottom solder mask layer 60 is in a cross shape to separate the four bottom pads 50 from each other. An identification portion 70 for distinguishing the electrode directions of the bottom pads 50 is further provided on the bottom solder mask layer 60. By way of example and not limitation, in some alternative embodiments, four bottom pads 50 are provided at the bottom for circuit connections of different light-emitting chips on the circuit board. In addition, the bottom pads 50 are evenly distributed at the four corners of the bottom of the substrate 10 to facilitate wiring. Then, by providing a cross-shaped bottom solder mask layer 60, the bottom pads 50 are separated to prevent solder from flowing and connecting between the bottom pads 50, so as to avoid damage to the circuit board. In addition, by providing the identification portion 70, it is easy to distinguish the electrode directions of the bottom pads 50.
[0033] Specifically, the distance between the edge of the hollow groove 32 and the outer edge of the conductive portion 22 is greater than a preset value. During specific implementation, it is necessary to limit the distance between the hollow groove 32 and the conductive portion 22 to ensure that the solder mask layer 30 on the conductive portion 22 covers a sufficient area, thereby ensuring both the effect of the solder mask layer 30 and that the area of the hollow groove 32 is large enough to improve the heat dissipation effect of the substrate 10. Preferably, the distance between the hollow groove 32 and the conductive portion 22 should be greater than 10 um.
[0034] In addition, via holes 11 are provided on the substrate 10, and connectors are provided in the via holes 11 to connect multiple conductive portions 22 to multiple bottom pads 50 respectively. During specific implementation, via holes 11 are formed on the substrate 10, and connectors are arranged in the via holes 11 to connect the conductive portion 22 and the bottom pad 50, thereby realizing the basic functions of the circuit board. In addition, during the actual manufacturing process, after drilling the substrate 10, a liquid conductive filler is usually provided in the via holes 11. For example, it can be copper liquid, etc. After the liquid conductive filler cools and hardens, the connectors are formed.
[0035] Specifically, a plurality of grooves 12 are evenly distributed on the substrate 10, and the plurality of grooves 12 are respectively located at the bottoms of the plurality of hollow grooves 32. By providing the grooves 12 at the bottoms of the hollow grooves 32, when the encapsulation layer 40 is provided, since the encapsulation layer 40 is epoxy resin and is provided in a liquid state on the substrate 10 and the solder mask layer 30, and after the liquid epoxy resin hardens, the encapsulation layer 40 is formed. Then, the epoxy resin will fill into the grooves 12, increasing the contact area between the encapsulation layer 40 and the substrate 10, further improving the bonding force between the two, and avoiding the situation where the encapsulation layer 40 is separated from the substrate 10.
[0036] In addition, the cross-sectional area of the groove 12 gradually increases from one side close to the solder resist layer 30 to the other side. Furthermore, the cross-sectional shape of the groove 12 is T-shaped or trapezoidal. In addition, by setting the cross-sectional area of the groove 12 to be gradual, specifically, it can be set to be T-shaped or trapezoidal, so that after the liquid encapsulation layer 40 hardens in the groove 12, the part of the encapsulation layer 40 located in the groove 12 interferes with the groove 12, thereby further increasing the difficulty of separating the encapsulation layer 40 from the substrate 10, and improving the bonding force between the encapsulation layer 40 and the substrate 10. In addition, the groove 12 is preferably a trapezoidal groove, which is easy to process, and has an inclined surface to facilitate the epoxy resin to flow into the groove 12, and it is easy to fill the groove 12, thereby avoiding the presence of bubbles in the groove 12 and reducing the bonding effect between the encapsulation layer 40 and the substrate 10.
[0037] Specifically, the ends of the solder resist layer 30 are flush with the substrate 10 so that each hollow groove 32 is independent of each other. In a specific implementation, the hollow grooves 32 are evenly distributed and not connected to each other, thereby ensuring that the contact area between the substrate 10 and the solder resist layer 30 is evenly distributed and the bonding force between the two is ensured.
[0038] In summary, the circuit board in the above-mentioned embodiment of the utility model is provided with a plurality of hollow grooves 32 by arranging a solder resist layer 30 on the substrate 10 and arranging a window area 31 on the solder resist layer 30 for exposing the solder pad 21, so that the conductive part 22 is located below the solder resist layer 30 between the hollow grooves 32. Since a plurality of hollow grooves 32 are added to the solder resist layer 30, the heat received by the substrate 10 can be quickly dissipated during the subsequent reflow soldering process, thereby avoiding the condition that the substrate 10 is deformed by heat. In addition, due to the hollow design, the contact surface between the packaging layer 40 and the solder resist layer 30 and the substrate 10 is uneven, thereby increasing the direct bonding force between each other, so that the packaging layer 40 will not be easily detached. In addition, since the packaging layer 40 is in direct contact with the substrate 10 in some areas without the obstruction of the solder resist layer 30, the bonding effect between the packaging layer 40 and the substrate 10 is better, thereby enhancing the local bonding force and improving the sealing effect here, thereby improving the airtightness of the lamp bead. Therefore, the utility model solves the problem in the prior art that the substrate 10 is easily deformed and the packaging layer 40 is easily warped during the production process of the circuit board, which affects the quality of the circuit board.
[0039] In addition, the utility model also provides an electronic device, which includes the above-mentioned circuit board.
[0040] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.
[0041] The above-described embodiments merely represent several implementation manners of the present utility model. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several modifications and improvements can still be made, and these all belong to the protection scope of the present utility model. Therefore, the protection scope of the patent of the present utility model shall be subject to the appended claims.
Claims
1. A circuit board, characterized in that: It includes a substrate, a copper foil layer arranged on the substrate, a solder resist layer arranged on the copper foil layer, and a packaging layer arranged on the solder resist layer, the copper foil layer includes a plurality of pads and a plurality of conductive parts extending outward from the pads, a window area is provided in the middle of the solder resist layer to expose the pads, a plurality of hollow grooves are provided on the outer side of the solder resist layer, and the conductive parts are located below the solder resist layer between the hollow grooves.
2. The circuit board according to claim 1, characterized in that: A plurality of bottom pads and a bottom solder resist layer are provided at the bottom of the substrate, and the bottom solder resist layer is arranged between the plurality of bottom pads to separate the bottom pads from each other.
3. The circuit board according to claim 2, characterized in that: The bottom of the substrate is provided with four bottom pads distributed at the four corners of the bottom of the substrate, the bottom solder resist layer is in a cross shape to separate the four bottom pads from each other, and the bottom solder resist layer is also provided with a marking portion for distinguishing the direction of the bottom pad electrode.
4. The circuit board according to claim 1, characterized in that: The distance between the edge of the hollow groove and the outer edge of the conductive portion is greater than a preset value.
5. The circuit board according to claim 2, characterized in that: The substrate is provided with a conducting hole, and a connecting piece is provided in the conducting hole so that the plurality of conducting parts are respectively connected to the plurality of bottom pads.
6. The circuit board according to claim 1, characterized in that: A plurality of grooves are evenly distributed on the substrate, and the plurality of grooves are respectively located at the bottom of the plurality of hollow grooves.
7. The circuit board according to claim 6, characterized in that: The cross-sectional area of the groove gradually increases from one side close to the solder resist layer to the other side.
8. The circuit board according to claim 7, characterized in that: The cross-sectional shape of the groove is T-shaped or trapezoidal.
9. The circuit board according to claim 4, characterized in that: Multiple ends of the solder resist layer are flush with the substrate, so that each of the hollow grooves is independent of each other.
10. An electronic device, characterized in that: A circuit board comprising any one of claims 1 to 9.