Circuit board, circuit board preparation method and electronic equipment

Abstract

The present application discloses a circuit board, a method for preparing a circuit board, and an electronic device. The circuit board includes a component layer and a first base layer and a first conductive layer stacked in sequence along a first direction. The component layer includes a plurality of components. The first base layer includes a first surface and a second surface arranged opposite each other along the first direction, the first surface facing the first conductive layer, the components embedded in the first base layer, and the components do not protrude from the first surface. The first conductive layer is electrically connected to the components. Through the above scheme, the thickness of the circuit board is reduced, the degree of freedom of accessory layout is increased, and the problem of interference with accessories around the circuit board caused by overflow of waterproof glue or fixing glue when setting is avoided. The circuit board obtained by the present application has high reliability.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a circuit board, a method for preparing a circuit board, and an electronic device. Background Art

[0002] A circuit board, also known as a printed circuit board, consists of a substrate, a conductive layer, and components such as resistors and capacitors. Conventional resistor and capacitor components are mounted using surface mount technology (SMT). These components are soldered to the circuit board's surface using reflow or dip soldering, then secured with adhesive and coated with waterproof adhesive to protect them from moisture.

[0003] On the one hand, since the resistor and capacitor components are located at designated positions on the surface of the circuit board, other accessories corresponding to these positions need to be avoided, affecting the layout of the accessories; on the other hand, the resistor and capacitor components are easily bumped and cause circuit breakage abnormalities; in addition, when applying waterproof glue and fixing glue, glue overflow is likely to occur, causing interference with the accessory structure. Summary of the Invention

[0004] The main technical problem solved by the present application is to provide a circuit board, a method for preparing a circuit board, and an electronic device, which can reduce the thickness of the circuit board, reduce the probability of interference with corresponding accessories, and increase the reliability of the circuit board.

[0005] In order to solve the above technical problems, a technical solution adopted in this application is: providing a circuit board, including a first base layer and a first conductive layer stacked in sequence along a first direction; the component layer includes a plurality of components; the first base layer includes a first surface and a second surface arranged opposite to each other along the first direction, the first surface faces the first conductive layer, and the component does not protrude from the first surface; the first conductive layer is electrically connected to the component.

[0006] In order to solve the above technical problems, another technical solution adopted in this application is: to provide a circuit board preparation method for preparing the circuit board in any embodiment, the preparation method including fixing the component layer on the first base layer so that the component layer is embedded in the first base layer and the component does not protrude from the first surface; stacking a first conductive layer on the first base layer; wherein the first conductive layer covers the component layer, and the first conductive layer is electrically connected to the component layer.

[0007] In order to solve the above technical problems, another technical solution adopted in this application is: to provide an electronic device, including the circuit board in any embodiment.

[0008] The beneficial effects of the present application are as follows: Different from the prior art, the circuit board of the present application has components embedded in the first base layer and the components do not protrude from the surface facing the first conductive layer. Since the components are embedded inside the circuit board, the thickness of the circuit board is reduced. After the first base layer and the first conductive layer are stacked, no protrusions caused by the components will be formed on the surface of the circuit board, thus avoiding interference of accessories outside the circuit board with the circuit board, improving the reliability of the circuit board, and the accessories outside the circuit board reduce the need to set up avoidance structures for the component layer in order to protect the components, thereby increasing the freedom of accessory layout. In addition, since the component layer is embedded in the first base layer, the component layer is effectively protected. Therefore, on the one hand, there is no need to set up waterproof glue for waterproofing, and on the other hand, there is no need to set up additional fixing glue for secondary fixing, thus avoiding the problem of interference with accessories around the circuit board caused by overflow of glue when setting waterproof glue or fixing glue. The circuit board prepared by the preparation method of the present application is thin in thickness and highly reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a schematic structural diagram of an embodiment of a circuit board of the present application;

[0010] Figure 2 is a side view of an embodiment of the component layer of the present application;

[0011] Figure 3 It is a front view of an embodiment of the component layer of the present application;

[0012] Figure 4 This is a schematic structural diagram of another embodiment of the circuit board of the present application;

[0013] Figure 5 This is a structural diagram of another embodiment of the circuit board of the present application;

[0014] Figure 6 This is a flow chart of an embodiment of a method for preparing a circuit board according to the present application;

[0015] Figure 7 This is a flow chart of step one of the circuit board preparation method of the present application;

[0016] Figure 8 It is a structural diagram of the first base layer implementation method of this application. DETAILED DESCRIPTION

[0017] To make the objectives, technical solutions, and effects of this application more clear and explicit, the present application is further described in detail below with reference to the accompanying drawings and examples. Obviously, the described examples are only some of the examples of this application, not all of them. Based on the examples in this application, all other examples obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0018] See Figure 1 , Figure 1 Schematic diagram of the structure of a circuit board according to an embodiment of the present application. The circuit board comprises a first base layer 1, a component layer 2, a first conductive layer 31, and optionally, a first protective layer 41 and a first electromagnetic shielding layer 51.

[0019] Specifically, the circuit board includes a first direction ( Figure 1 The first base layer 1, the first conductive layer 31, the first protective layer 41 and the first electromagnetic shielding layer 51 are stacked in sequence (in the X direction); the first base layer 1 includes a first surface 1a and a second surface 1b arranged opposite to each other, and the first surface 1a faces the first conductive layer 31; the element layer 2 includes a plurality of elements 21, the elements 21 are embedded in the first base layer 1, and the elements 21 do not protrude from the first surface 1a, and the first conductive layer 31 is electrically connected to the elements 21.

[0020] Specifically, the first base layer 1 can be made of a rigid material or a flexible material. When the circuit board is a rigid circuit board, the first base layer 1 can be made of a rigid material such as a phenolic paper laminate, an epoxy paper laminate, a polyester glass felt laminate or an epoxy glass cloth laminate; when the circuit board is a flexible circuit board FPC, the first base layer 1 can be made of a flexible material such as a polyester film, a polyimide film, a fluorinated ethylene propylene film, etc. The component 21 can be a capacitor and resistor component, optionally, it can be a thin film capacitor or a thin film resistor. The first conductive layer 31 can be made of copper foil, and a circuit layer is provided on the copper foil. Optionally, a first protective layer 41 is provided on the outside of the first conductive layer 31. The first protective layer 41 can be a cover film protective film, which is used to protect the first conductive layer 31 and prevent environmental moisture from affecting the first conductive layer 31 and the component layer 2. Optionally, a first electromagnetic shielding layer 51 can be provided outside the first protective layer 41 to shield electromagnetic radiation.

[0021] The circuit board of the present application has component 21 embedded in the first base layer 1. Since component 21 is embedded and arranged inside the circuit board and does not protrude from the first surface 1a, the thickness of the circuit board is reduced. After the first base layer 1 and the first conductive layer 31 are stacked, no protrusion caused by component 21 will be formed on the surface of the circuit board, thereby avoiding interference with the circuit board by accessories outside the circuit board and improving the reliability of the circuit board. In addition, the accessories outside the circuit board reduce the need to set up avoidance structures for component layer 2 to protect component 21, thereby increasing the freedom of accessory layout. For example, the accessory can be a housing of an electronic device, and the housing reduces the need for additional avoidance structures for the circuit board of the present application. In addition, since component layer 2 is covered by the first conductive layer 31, optionally, the first conductive layer 31 is covered by the first protective layer 41 and the first electromagnetic shielding layer 51, and component layer 2 is embedded in the first base layer 1, component layer 2 is effectively waterproofed and fixed. Therefore, on the one hand, there is no need to set waterproof glue outside the component 21 for waterproofing, and on the other hand, there is no need to set up additional fixing glue for secondary fixing, thereby avoiding the problem of interference with peripheral accessories of the circuit board caused by glue overflow when setting waterproof glue or fixing glue.

[0022] Further, see Figure 1 , component 21 does not protrude from second surface 1b. That is, in the first direction, the thickness of component layer 2 is less than or equal to the thickness of first base layer 1. Under this technical solution, both sides of component 21 do not protrude from first base layer 1, further ensuring that no protrusions are formed on the surface of the circuit board, further improving the reliability of the circuit board.

[0023] Optionally, see Figure 2 , Figure 2 This is a side view of an embodiment of the component layer of the present application. In this embodiment, the component layer 2 also includes a second base layer 23, and multiple components 21 are fixedly arranged on the side of the second base layer 23 facing the first conductive layer 31. The second base layer 23 is used to fix and install multiple components 21 and acts as an insulating base. Optionally, the second base layer 23 does not protrude from the second surface 1b, and neither side of the component layer 2 protrudes from the first base layer 1, further ensuring that no protrusions are formed on the surface of the circuit board, further improving the reliability of the circuit board. Specifically, the material of the second base layer 23 is an insulating material such as ceramic or silicone.

[0024] Optionally, continue to Figure 2 In this embodiment, the component layer 2 also includes a conductive connecting member 22, and the conductive connecting member 22 includes a first end 221 and a second end 222. The first end 221 is fixedly arranged on the side of the second base layer 23 facing the component 21, and the second end 222 is fixedly arranged on the side of the component 21 facing the first conductive layer, and the second end 222 is electrically connected to the first conductive layer.

[0025] Specifically, the conductive connector 22 can be a nickel-tin plated layer, covering the first surface 1a, and fixedly connected to the second base layer 23 and the element 21 at its two ends. The conductive connector 22 further fixes the element 21 and the second base layer 23, and is used to conduct electricity between the element 21 and the first conductive layer 31.

[0026] Optionally, the conductive connecting member 22 further includes a connecting segment 223 disposed between the first end 221 and the second end 222. The connecting segment 223 is fixedly disposed along the first direction ( Figure 2 On the side extending in the X direction), the element 21 and the second base layer 23 are further fixed.

[0027] Optionally, see Figure 3 , Figure 3 It is a front view of an embodiment of the element layer of the present application. A plurality of conductive connectors 22 are arranged at intervals along the circumference of the element 21. Optionally, a plurality of conductive connectors 22 are arranged at even intervals. Specifically, in the present embodiment, the element 21 is circular, and a total of four conductive connectors 22 are arranged corresponding to each element 21, and two adjacent conductive connectors 22 are spaced 90° apart. Of course, in other embodiments, the element 21 can be of other shapes, and the number of conductive connectors 22 is not limited. For example, when the element 21 is rectangular, a pair of conductive connectors 22 can be provided, respectively provided on a set of opposite sides of the rectangle; when the element 21 is triangular, three conductive connectors 22 can be provided, respectively provided on the three sides of the triangle.

[0028] Optionally, continue to Figure 3 In this embodiment, a buffer hole 231 extending along the first direction is provided on the second base layer 23. The buffer hole 231 is located outside the orthographic projection of the component 21 on the second base layer 23. The buffer hole 231 can buffer the torsional stress of the second base layer 23, reduce the brittleness of the second base layer 23, reduce the probability of damage to the second base layer 23, and ensure that the second base layer 23 fixes the component 21.

[0029] Furthermore, the buffer hole 231 passes through the second base layer 23. Of course, in other embodiments, the buffer hole 231 may not pass through the second base layer 23, that is, a buffer groove is formed on the second base layer 23.

[0030] Furthermore, the orthographic projection of the buffer hole 231 on the second base layer 23 is a circle, which reduces local stress and ensures the reliability of the second base layer 23 and the component layer 2 .

[0031] See Figure 4 , Figure 4 This is a schematic diagram of the structure of another embodiment of the circuit board of the present application. In this embodiment, it includes sequentially (along the first direction) Figure 4The circuit board comprises a first base layer 1, a first conductive layer 31, a first protective layer 41, and a first electromagnetic shielding layer 51 stacked in a direction opposite to the first direction (in the X direction in the figure). The circuit board also includes a second conductive layer 32, a second protective layer 42, and a second electromagnetic shielding layer 52 stacked in sequence in the opposite direction of the first direction (in the opposite direction of the X direction in the figure). The second conductive layer 32 is disposed on the side of the first base layer 1 facing away from the first conductive layer 31. The component layer 2 includes a plurality of components 21, which are embedded in the first base layer 1 and do not protrude from the first surface 1a. The first conductive layer 31 covers the component layer 2 and is electrically connected to the components 21. The second conductive layer 32 covers the component layer. Both sides of the circuit board can protect the component layer 2, and the second conductive layer 32 extends the circuit.

[0032] Optionally, see Figure 5 , Figure 5 FIG2 is a schematic diagram of the structure of another embodiment of the circuit board of the present application. In this embodiment, a second component layer 6 is further included. The structure of the second component layer 6 is consistent with that of the component layer 2. The second component layer 6 includes a plurality of second components 61. The second components 61 are embedded in the first base layer 1 and do not protrude from the second surface 1b. The second conductive layer 32 covers the second component layer 6 and is electrically connected to the second components 61.

[0033] Specifically, the second component layer 6 has the same structure as the component layer 2, and both are embedded in the first base layer 1. The second component layer 6 and the component layer 2 are aligned in the first direction ( Figure 5 The components 21 and 61 are arranged on the side facing the first conductive layer 31 and the second conductive layer 32, respectively. Alternatively, the component layer 2 and the second component layer 6 are arranged side by side perpendicular to the first direction. This technical solution increases the number of resistors and capacitors without increasing the thickness of the circuit board, allowing the resistors and capacitors to connect the conductive layers on both sides.

[0034] See Figure 6 , Figure 6 1 is a flow chart of an embodiment of a method for preparing a circuit board of the present application. The method is used to form a circuit board as described in any of the above embodiments, and the method comprises:

[0035] Step S101: Fix the component layer 2 to the first base layer 1 so that the component 21 is embedded in the first base layer 1 and does not protrude from the first surface 1a;

[0036] Step S102 : stacking a first conductive layer 31 on the first base layer 1 ; wherein the first conductive layer 31 is electrically connected to the component layer 2 .

[0037] The circuit board prepared by the preparation method of the present application is thin and has high reliability.

[0038] Optionally, before step S101: fixing the component layer 2 to the first base layer 1, the process further includes:

[0039] Step S201: Multiple components 21 are fixedly positioned on the side of the second base layer 23 facing the first conductive layer 31. Specifically, using thin-film resistors as the components 21, this step includes depositing an electrode layer and a resistor layer on the second substrate 23 (ceramic or silicone), then heat-treating and curing the conductive layer, and forming an electrode pattern using, for example, photolithography. For thin-film resistors, the resistance can be adjusted by adjusting the orthographic projection area of ​​the components 21 on the second base layer 23.

[0040] Step S202: The conductive connector 22 is fixedly arranged on the side of the component layer 2 facing the first conductive layer 31, wherein the first end 221 of the conductive connector 22 is fixedly arranged on the side of the second base layer 23 facing the component 21, and the second end 222 of the conductive connector 22 is fixedly arranged on the side 31 of the component 21 facing the first conductive layer, and the second end 222 is electrically connected to the first conductive layer 31.

[0041] Optionally, before step S101: fixing the component layer 2 to the first base layer 1, step S203 is also included: opening a buffer hole 231 on the second base layer 23, wherein the buffer hole 231 extends along the first direction and is located outside the orthographic projection of the component 21 on the second base layer 23.

[0042] Optionally, the present application also includes a method for preparing the second component layer 6 , which is consistent with the method for preparing the component layer 2 and will not be described in detail here.

[0043] Optionally, see Figure 7 , Figure 7 This is a flow chart of one step of the circuit board manufacturing method of the present application. In step S101, the step of fixing the component layer 2 on the first base layer 1 also includes:

[0044] Step S301: Refer to Figure 8 , Figure 8 This is a schematic structural diagram of an embodiment of the first base layer 1 of the present application. A fixing groove 11 is provided on the first base layer 1, and the component layer 2 is provided in the fixing groove 11. The shape of the fixing groove 11 is adapted to the component layer 2.

[0045] Step S302: Hot pressing the first base layer 1 and the component layer 2 to fuse the first base layer 1 and the component layer 2. Specifically, the first base layer 1 has a lower melting point and the component layer 2 has a higher melting point. When hot pressing the two at a temperature between their melting points, the first base layer 1 fuses to the component layer 2, achieving fixation between the two.

[0046] In one embodiment, the present application also provides an electronic device, including the circuit board in any of the above embodiments. The electronic device can be a mobile phone, a tablet computer, a wearable device, etc.

[0047] The above is only an implementation method of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A circuit board, characterized in that: include: A first base layer and a first conductive layer are sequentially stacked along a first direction; The component layer includes a plurality of components and a second base layer, wherein the plurality of components are fixedly arranged on a side of the second base layer facing the first conductive layer; The first base layer includes a first surface and a second surface opposite to each other along the first direction, the first surface faces the first conductive layer, the component layer is embedded in the first base layer, and the component does not protrude from the first surface, and the second base layer does not protrude from the second surface; The first conductive layer is electrically connected to the element; The element layer also includes a conductive connector, which includes a first end and a second end. The first end is fixedly arranged on the side of the second base layer facing the element, and the orthographic projection of the first end on the second base layer is located outside the orthographic projection of the element on the second base layer. The second end is fixedly arranged on the side of the element facing the first conductive layer, and the second end is electrically connected to the first conductive layer. A plurality of conductive connectors are arranged at intervals along the circumference of the element.

2. The circuit board according to claim 1, wherein: The second base layer is made of ceramic or silicone.

3. The circuit board according to claim 1, wherein: The plurality of conductive connecting members are evenly spaced apart.

4. The circuit board according to claim 1, wherein: A buffer hole extending along the first direction is provided on the second base layer, and the buffer hole is located outside the orthographic projection of the component on the second base layer.

5. The circuit board according to claim 4, characterized in that The buffer hole passes through the second base layer.

6. The circuit board according to claim 4, characterized in that The orthographic projection of the buffer hole on the second base layer is a circle.

7. The circuit board according to claim 1, wherein: The circuit board also includes: a second electromagnetic shielding layer, a second protective layer, and a second conductive layer stacked in sequence along the first direction, wherein the second conductive layer faces the second surface; The second element layer includes a plurality of second elements, the second elements are embedded in the first base layer, and the second elements do not protrude from the second surface. The second conductive layer covers the second element layer and is electrically connected to the second elements.

8. A method for preparing a circuit board, for forming the circuit board according to any one of claims 1 to 7, characterized in that: The preparation method comprises: Fixing a plurality of components on a side of the second base layer facing the first conductive layer; Fixing the component layer to the first base layer so that the components are embedded in the first base layer and do not protrude from the first surface; A first conductive layer is stacked on the first base layer; wherein the first conductive layer is electrically connected to the element layer.

9. The method for preparing a circuit board according to claim 8, wherein: Before fixing the component layer to the first base layer, the method further includes: A conductive connector is fixedly arranged on the side of the component layer facing the first conductive layer, wherein the first end of the conductive connector is fixedly arranged on the side of the second base layer facing the component, and the orthographic projection of the first end on the second base layer is located outside the orthographic projection of the component on the second base layer, and the second end of the conductive connector is fixedly arranged on the side of the component facing the first conductive layer, and the second end is electrically connected to the first conductive layer.

10. The method for preparing a circuit board according to claim 9, wherein: Before fixing the component layer on the first base layer, the method further includes opening a buffer hole on the second base layer, wherein the buffer hole extends along the first direction and is located outside the orthographic projection of the component on the second base layer.

11. The method for preparing a circuit board according to claim 8, wherein: The step of fixing the component layer on the first base layer further comprises: A fixing groove is provided on the first base layer, and the component layer is provided in the fixing groove; the first base layer and the component layer are hot-pressed to fuse the first base layer and the component layer.

12. An electronic device, characterized in that: Comprising the circuit board as described in any one of claims 1-7.

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