WO2024017133A1

WO2024017133A1 - Circuit board structure and manufacturing method therefor, camera module, and electronic device

Info

Publication number: WO2024017133A1
Application number: PCT/CN2023/107240
Authority: WO
Inventors: 刘庆; 刘峰
Original assignee: 维沃移动通信有限公司
Priority date: 2022-07-20
Filing date: 2023-07-13
Publication date: 2024-01-25
Also published as: CN115209617A

Abstract

The present application relates to the technical field of electronic devices and discloses a circuit board structure and a manufacturing method therefor, a camera module, and an electronic device. The circuit board structure comprises: a first circuit board and a second circuit board which are connected to each other. A first via hole is formed on at least one first position area on the first circuit board; a second via hole is formed on at least one second position area on the second circuit board; the first via hole is communicated with the second via hole; a first conductive substance is respectively arranged in the first via hole and the second via hole; the first conductive substance is used for electrically connecting the first circuit board and the second circuit board.

Description

Circuit board structure and manufacturing method, camera module and electronic equipment

Cross-references to related applications

This application claims priority to Chinese Patent Application No. 202210862329.3 filed in China on July 20, 2022, the entire content of which is incorporated herein by reference.

Technical field

This application belongs to the technical field of electronic equipment, and specifically relates to a circuit board structure and its production method, a camera module and electronic equipment.

Background technique

Currently, with the development and popularization of smartphones, people expect smartphones to have higher and higher requirements for photographing effects, which makes camera designs more and more complex. Among them, the circuit board in the camera module is an indispensable component. As the design requirements of the camera increase, the corresponding circuit board design becomes more and more complex, which puts forward higher requirements for the circuit board manufacturing process. At the same time, it also This greatly affects the production cost of the camera module circuit board.

Specifically, as shown in Figure 1, due to the limitations of the definition of each pin function (PIN) of the driver IC in the camera module in the module, the PIN inside the driver IC (the PIN in the dotted box in the figure) ) requires leads to the outside, and the industry usually adopts a blind and buried hole design, in which the driver IC can drive the motor movement. As shown in Figure 2, the design of the blind and buried via circuit board is relatively complex, which involves the blind hole a between the first layer circuit (board) L1 and the second layer circuit L2, the second layer circuit L2 and the third layer circuit L3 The blind hole b between the third layer circuit L3 and the fourth layer circuit L4 is the blind hole c between the third layer circuit L3 and the fourth layer circuit L4. Based on this, as shown in Figure 3, the production process needs to first make the inner layer circuit and process the inner layer hole. Then the laminate is pressed, and then the outer layer circuit is made. The outer layer blind hole also needs to be processed, and finally the hole plating process is performed; this results in a long process for making vias between each layer and a high risk of quality failure. , the cost is also higher; in the end, the product cost is high, and the product cannot maintain a better price/performance ratio.

It can be seen from the above that the circuit board structure in the prior art has problems such as complicated production processes due to the provision of blind holes.

Contents of the invention

The purpose of the embodiments of the present application is to provide a circuit board structure and its manufacturing method, camera module and electronic equipment, which can solve the problem in the prior art that the production process of the circuit board structure is complicated due to the provision of blind holes.

In a first aspect, embodiments of the present application provide a circuit board structure, which includes:

A first circuit board and a second circuit board are connected, a first via hole is provided in at least one first location area on the first circuit board, and a first via hole is provided in at least one second location area on the second circuit board. A second via hole is provided; the first via hole and the second via hole are connected;

Wherein, a first conductive material is disposed in the first via hole and the second via hole respectively, and the first conductive material is used to conduct the first circuit board and the second circuit board.

In a second aspect, embodiments of the present application provide a camera module, including: a circuit board structure as described in the first aspect.

In a third aspect, an embodiment of the present application provides an electronic device, including: a camera module as described in the second aspect.

In a fourth aspect, embodiments of the present application provide a circuit board structure manufacturing method, which is applied to the circuit board structure described in the first aspect. The method includes:

Obtain a second circuit board in the circuit board structure, and etch inner circuits on the second circuit board;

Superimpose the first circuit board on the first side of the etched second circuit board;

Laminate the stacked first circuit board and second circuit board;

Etching outer circuits on the laminate first circuit board;

After etching the outer layer circuit, drilling through holes is performed on the first circuit board and the second circuit board;

Electroplating the openings on the drilled first circuit board and the second circuit board;

Wherein, the openings on the first circuit board and the second circuit board are connected.

In the embodiment of the present application, the circuit board structure is configured by: a connected first circuit board and a second circuit board, and a first via hole is provided in at least a first location area on the first circuit board, A second via hole is provided in at least a second position area on the second circuit board; the first via hole and the second via hole are connected; wherein, the first via hole and the second via hole are connected to each other; The two via holes are respectively provided with a third A conductive material, the first conductive material is used to conduct the first circuit board and the second circuit board; it is possible to use a through-hole structure to connect the circuit boards without the need to provide blind holes, thereby The production process of the circuit board is simplified, the difficulty of the production process of the circuit board is reduced, the production cycle of the circuit board is shorter, and the stability of the circuit board is also improved; it is a good solution to the problem of blind holes in the circuit board structure in the existing technology. Problems that lead to complex production processes.

Description of drawings

Figure 1 is a schematic diagram of driver IC pin definition in the prior art;

Figure 2 is a schematic diagram of a conventional 4-layer blind and buried via design in the prior art;

Figure 3 is a production flow chart of a conventional 4-layer blind and buried via substrate in the prior art;

Figure 4 is a schematic structural diagram of the circuit board in the embodiment of the present application;

Figure 5 is a schematic diagram of the circuit board structure manufacturing method in the embodiment of the present application;

Figure 6 is a schematic diagram of the camera module in the embodiment of the present application;

Figure 7 is a schematic diagram of the wiring near the IC in the circuit board in the embodiment of the present application;

Figure 8 is a schematic diagram of the pad position of the camera module circuit board in the embodiment of the present application;

Figure 9 is a schematic diagram of the specific implementation flow of the circuit board structure manufacturing method in the embodiment of the present application;

Figure 10 is a schematic structural diagram of the camera module IC in the embodiment of the present application;

Figure 11 is an example of the pad position of the camera module circuit board in the embodiment of the present application;

Figure 12 is an example 2 of the pad position of the camera module circuit board in the embodiment of the present application;

Figure 13 is a schematic diagram of the position of the pads on the circuit board of the camera module in the embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art fall within the scope of protection of this application.

The terms "first", "second", etc. in the description and claims of this application are used to distinguish similar objects and are not used to describe a specific order or sequence. It should be understood that data so used are interchangeable under appropriate circumstances so that embodiments of the present application can be used in other ways than as illustrated or described herein. The objects distinguished by "first", "second", etc. are usually of the same type, and the number of objects is not limited. For example, the first object may be one or multiple. In addition, "and/or" in the description and claims indicates at least one of the connected objects, and the character "/" generally indicates that the related objects are in an "or" relationship.

The circuit board structure provided by the embodiments of the present application will be described in detail below with reference to the accompanying drawings through specific embodiments and application scenarios.

The circuit board structure provided by the embodiment of the present application, as shown in Figure 4, includes:

The first circuit board 1 and the second circuit board 2 are connected. A first via hole 3 is provided in at least one first location area on the first circuit board 1. At least one first via hole 3 is provided on the second circuit board 2. A second via hole 4 is provided in the second position area; the first via hole 3 and the second via hole 4 are connected; wherein, the first via hole 3 and the second via hole 4 are respectively A first conductive material is provided, and the first conductive material is used to conduct the first circuit board 1 and the second circuit board 2 .

Figure 4 takes a four-layer circuit board as an example. It may include: two first circuit boards 1 and two second circuit boards 2. The first circuit board 1 includes: a first circuit layer L1 and a fourth layer of circuits. Layer L4, the second circuit board 2 includes: a second circuit layer L2 and a third circuit layer L3, but is not limited thereto. The conductive materials in the first via hole and the second via hole may be the same or different, and are not limited here.

In the embodiment of the present application, the circuit board structure is provided with: a connected first circuit board and a second circuit board, and a first via hole is provided in at least a first position area on the first circuit board, A second via hole is provided in at least a second position area on the second circuit board; the first via hole and the second via hole are connected; wherein, the first via hole and the third via hole are connected to each other; A first conductive material is respectively provided in the two via holes, and the first conductive material is used to conduct the first circuit board and the second circuit board; it is possible to use a through-hole structure to connect the circuit boards, and It is no longer necessary to set up blind holes, thereby simplifying the production process of the circuit board, reducing the difficulty of the circuit board production process, making the production cycle of the circuit board shorter, and also improving the stability of the circuit board; it is a good solution to the problems in the existing technology. The circuit board structure has complicated production processes due to blind holes.

Further, a first insulating layer is provided between the first circuit board and the second circuit board, a third via hole is provided on the first insulating layer, and the third via hole is connected to the first The via hole is connected to the second via hole; wherein, a second conductive material is provided in the third via hole, and the second conductive material conducts the circuit boards on both sides of the first insulating layer.

This can ensure the insulation between circuit boards; regarding "the second conductive material conducts the circuit boards on both sides of the first insulating layer", it can be: the second conductive material and the first via hole The first conductive material in the second via hole is connected to the first conductive material; the second conductive material is the same as or different from the first conductive material.

Wherein, the first circuit board is provided with at least one chip pin, and the chip pin is connected to the first conductive material.

This can ensure the normal realization of pin functions. The first circuit board can be used as the outer circuit board, but it is not limited to this.

In the embodiment of the present application, the number of pins of the chip is less than the total number of pins of the chip; specifically, the pins provided on the circuit board are necessary pins; this can increase the number of via holes and wiring Space. In the embodiment of the present application, the first circuit board is provided with a blank area corresponding to the optional chip pins; wherein the wiring of the at least one chip pin is provided in the space between the pads and the space between the pads. /or within the blank area.

Among them, "the number of pins of the chip is less than the total number of pins of the chip" can be embodied in the following: the chip has more than one pin, and some of the pins are in a suspended or floating state. This means that the chip has more than one pin. There is no current or signal passing through some pins in the in-use or non-use state, and the circuit board in the projection area directly below this part of the pins has no corresponding pad structure; further, the circuit board in the projection area directly below this part of the pins It is possible to have vias or traces and use ink to cover the vias or traces, but is not limited to this.

In the embodiment of the present application, the necessary pins may be determined based on the pin definition of the chip and the first rule; wherein the first rule includes at least one of the following: the probability of being used is greater than the first threshold; the replaced The probability is less than the second threshold, but is not limited to this.

In the embodiment of the present application, at least one of the chip pins is a first type pin, and the pad of the first type pin is circular and has a diameter of less than 0.3mm; or, the first type pin has a There is an avoidance part on the pad, which can be reflected as a concave structure. For example, cutting off the edge of the pad makes the pad appear a non-complete circle, ensuring that the shape is ≥0.5 complete circles.

This further increases the space available for vias and traces.

In this embodiment of the present application, at least one of the chip pins is a second type pin, and the ink window size of the second type pin is smaller than or equal to the pad size of the second type pin.

This further increases the space available for vias and traces. The chip pins may be both first type pins and second type pins, which are not limited here. In this solution, reducing the ink window is beneficial to wiring (there needs to be a safe distance between the edge of the ink window and the line edge, and reducing the size of the ink window actually increases the safety distance).

An embodiment of the present application also provides a camera module, including: the above-mentioned circuit board structure.

The camera module provided by the embodiment of the present application can implement each process implemented by the circuit board structure embodiment mentioned above. To avoid repetition, the details will not be described here.

An embodiment of the present application also provides an electronic device, including: the above-mentioned camera module.

The electronic device provided by the embodiment of the present application can implement each process implemented by the above-mentioned camera module embodiment. To avoid duplication, the details will not be described here.

The embodiment of the present application also provides a method for manufacturing a circuit board structure, which is applied to the above-mentioned circuit board structure. As shown in Figure 5, the manufacturing method includes:

Step 51: Obtain the second circuit board in the circuit board structure, and etch inner circuits on the second circuit board;

Step 52: Superimpose the first circuit board on the first side of the etched second circuit board;

Step 53: Laminate the stacked first circuit board and second circuit board;

Step 54: Etch the outer circuit on the laminated first circuit board;

Step 55: After etching the outer layer circuit, drill through holes on the first circuit board and the second circuit board;

Step 56: Electroplating the openings on the drilled first circuit board and the second circuit board; wherein the openings on the first circuit board and the second circuit board are connected.

There is no restriction on which side of the second circuit board the first side of the second circuit board is.

In the embodiment of the present application, the second circuit board in the circuit board structure is obtained, and the inner circuit is etched on the second circuit board; the first side of the etched second circuit board is superimposed on the first side. Circuit board; laminate the stacked first circuit board and second circuit board; etch outer circuits on the laminate first circuit board; after etching the outer circuits, etching the first circuit board Drill through holes on the first circuit board and the second circuit board; perform electroplating on the holes on the drilled first circuit board and the second circuit board; wherein, the holes on the first circuit board and the second circuit board are The holes are connected; it is possible to use a through-hole structure to connect circuit boards without the need for blind holes, thus simplifying the wiring The production process of the circuit board reduces the difficulty of the circuit board production process, shortens the production cycle of the circuit board, and also improves the stability of the circuit board; it well solves the problem of production problems caused by blind holes in the circuit board structure in the prior art. Problems with complex processes.

In the embodiment of the present application, superposing the first circuit board on the first side of the etched second circuit board includes: sequentially superposing a first insulating layer and a third layer on the first side of the etched second circuit board. A circuit board.

This ensures insulation between circuit boards.

The following is an example of the circuit board structure and its manufacturing method provided by the embodiment of the present application. The circuit board structure takes the camera module circuit board as an example.

In response to the above technical problems, embodiments of the present application provide a circuit board structure and a manufacturing method thereof, which can be specifically implemented as a new camera module circuit board design solution to solve the pain points of complex circuit board design for high-end projects; compared with traditional Multi-layer (greater than or equal to 2 layers) circuit board design of the camera module. After analyzing the functions of the chip and camera module, the design of the circuit board is optimized, making the circuit board manufacturing process simpler, the circuit board performance more stable, and the camera The cost of camera modules is greatly reduced, ultimately making the product more cost-effective. Among them, it involves:

1. Combine the pin definition characteristics of the driver IC and the camera module, identify the PIN definitions that can be deleted (that is, non-essential pins), and do not design pads on the circuit board to save money. Space for circuit board routing design;

2. Optimize the soldering pads of the circuit board by cutting the soldering pads and reducing the size of the ink openings, thereby saving space for circuit board routing design;

3. Based on the above two points, it is possible to ensure that the module circuit board design space is sufficient, thereby avoiding the use of blind hole design and directly selecting through-hole design, which simplifies the production process of the circuit board and reduces the difficulty of the circuit board production process. The cycle time is shorter, and the stability of the circuit board is also improved.

First, the relevant components involved in this solution are explained, as shown in Figure 6, Figure 7, Figure 11 and Figure 13, where:

Protective film 5: used to protect the lens;

Lens 6: It is an optical lens, used to admit light to the module;

Motor 7: used to push the lens to move and achieve focusing;

IR8: is the filter;

Component 9: used to support IR;

Sensor 10 (sensor10): It is a photosensitive component that converts optical signals into electrical signals;

Circuit board 11: used for electrical connection and the load-bearing surface of the module;

IC12: is a driver chip that converts and outputs electrical signals;

Connector 13: used to connect the electrical signal between the whole machine and the camera module;

Via 14: used for multi-layer circuit boards, changing layers to connect electrical signals;

Pad 15: As the contact position with the IC on the circuit board;

Trace 16: The electrical signal connection function in the circuit board;

Ink window 17: No ink is printed at this location, and the pad can be exposed.

As shown in Figure 8, during the module design process, some PIN definitions inside the IC may not be used or can be easily replaced. Among them, PINs that are generally unnecessary or easily replaced include: ① PIN definitions that need to be used to assist detection during the production process of the IC unit itself; ② PIN definitions that do not need to be used for IC functions, such as: IC units can drive 3-axis anti-shake, But the actual module only requires 2-axis anti-shake; ③ IC special function general-purpose input and output port (General Purpose Input Output, GPIO port), GPIO port is a port that can configure special functions by itself; ④ The PIN function of IC is easily replaced by other ICs (Adding an IC can replace some of the functions of the original IC). At this time, individual PIN pins of the IC can be omitted, and the lines or pads in this area will not be designed during the circuit board design process. As shown in Figure 7, during the circuit board design, after reducing the unnecessary PINs, the corresponding circuit board does not need to be designed with the pads 15. At this time, the space that can be used for drilling the vias 14 and wiring can be freely used. increase. In addition, the spacing between the pads 15 can be increased by reducing the size of individual pads, so that wiring can be carried out between the pads. For example, the pad size is reduced from a conventional 0.3mm design to less than 0.25mm (this At the same time, you can also cut off the edge of the pad to make the pad appear a non-complete circle, ensuring that the shape is ≥ 0.5 complete circles); ultimately, the wiring near the IC can be completed smoothly, and as shown in Figure 4, the nearby The via hole is in the form of a through hole (corresponding to the communication between the first via hole 3 and the second via hole 4 mentioned above). Correspondingly, as shown in Figure 9, the circuit board first manufactures the inner layer circuit (corresponding to the above-mentioned second circuit board), then laminates the boards, and then manufactures the outer layer circuit (corresponding to the above-mentioned first circuit board). Finally, drilling and electroplating are enough, which greatly saves the substrate production process compared to traditional designs.

In addition, there are many types of ICs in camera modules, and there are many types of circuit board layers, such as 4-layer, 5-layer, 6-layer, 7-layer, etc. We will not list them all here.

Specific examples of solutions provided by the embodiments of this application are given below.

Example 1

Assuming that the camera module circuit board has 4 layers, the IC can drive the motor to move in three directions: horizontal, front and back, and up and down. As shown in Figure 10, an additional IC18 can be added to drive the motor to move up and down. This IC18 can be placed on the circuit board or inside the motor, so that the PINs for the up and down movement of the A1 and A2 motors inside the IC can be replaced. . When designing the module circuit board at this time, A1 and A2 are the networks for motor movement in the up and down direction, and A6, A7 and C7 are the PIN definitions used for special function configuration. Since the PIN pins of A1, A2, A6 and A7 are in this The functions in the solution are not used. As shown in Figure 11, the A1, A2, A6 and A7 pads of the IC are first omitted. The pads are removed during the circuit board design process and individual pads are reduced (remove the round ones). edge), the inner (pin) traces come out of the space between the pads, and the vias are designed as through holes, see the dotted box in Figure 11. The design of this example will not affect the overall dimensions of the module, the reliability of the module will be better, the circuit board production cycle of the module will be shorter, and the overall cost of the module will be lower.

Example 2

Assuming that the camera module circuit board has 6 layers, the IC can drive the motor to move in three directions: horizontal, front and back, and up and down. As shown in Figure 12, when designing the module circuit board at this time, due to the special module, there is no need for the IC to control the module to move up and down, so that D2 and D3 are not used for the network functions of the motor moving up and down. B7 and C7 , D7 and B10 are PIN definitions used in special function configuration. Since the PIN pins of B7, C7, D7 and B10 are not used in this solution, as shown in Figure 13, the PIN pins can be used in circuit board design. The D2, D3, B7, C7, D7 and B10 pads of the IC are omitted. The pads are removed during the circuit board design process. Individual pads are reduced (reduce the pad diameter), and the inner wiring is routed from the pads to the pads. The space between them is taken out, and the via hole is designed as a through hole. This design will not affect the overall dimensions of the module, the reliability of the module will be better, the circuit board production cycle of the module will be shorter, and the overall cost of the module will be lower.

From the above, the solution provided by the embodiment of this application:

1. Simplify the production process of the camera module circuit board, making the circuit board cost lower;

2. Reduce the potential failure points of the circuit board, making the quality of the circuit board more reliable;

3. The production cycle of circuit boards is shortened, making the product development cycle shorter.

It should be noted here that the above circuit board structure is not limited to camera modules, but can also be applied to other It has a circuit board structure.

It should be noted that, in this document, the terms "comprising", "comprises" or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article or device that includes a series of elements not only includes those elements, It also includes other elements not expressly listed or inherent in the process, method, article or apparatus. Without further limitation, an element defined by the statement "comprises a..." does not exclude the presence of additional identical elements in a process, method, article or apparatus that includes that element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, but may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved. Functions may be performed, for example, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus the necessary general hardware platform. Of course, it can also be implemented by hardware, but in many cases the former is better. implementation. Based on this understanding, the technical solution of the present application can be embodied in the form of a computer software product that is essentially or contributes to the existing technology. The computer software product is stored in a storage medium (such as ROM/RAM, disk , optical disk), including several instructions to cause a terminal (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in various embodiments of this application.

The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above-mentioned specific implementations. The above-mentioned specific implementations are only illustrative and not restrictive. Those of ordinary skill in the art will Inspired by this application, many forms can be made without departing from the purpose of this application and the scope protected by the claims, all of which fall within the protection of this application.

Claims

A circuit board structure including:

A first circuit board and a second circuit board are connected, a first via hole is provided in at least one first location area on the first circuit board, and a first via hole is provided in at least one second location area on the second circuit board. A second via hole is provided; the first via hole and the second via hole are connected;

Wherein, a first conductive material is disposed in the first via hole and the second via hole respectively, and the first conductive material is used to conduct the first circuit board and the second circuit board.
The circuit board structure according to claim 1, wherein a first insulating layer is provided between the first circuit board and the second circuit board, and a third via hole is provided on the first insulating layer. The third via hole is connected with the first via hole and the second via hole;

Wherein, a second conductive material is disposed in the third via hole, and the second conductive material conducts circuit boards on both sides of the first insulating layer.
The circuit board structure according to claim 1, wherein at least one chip pin is provided on the first circuit board, and the chip pin is connected to the first conductive material.
The circuit board structure according to claim 3, wherein the number of pins of the chip is less than the total number of pins of the chip.
The circuit board structure according to claim 3, wherein at least one of the chip pins is a first type pin, and the pad of the first type pin is circular and has a diameter less than 0.3mm; or, the The pad of the first type pin is provided with an escape portion.
The circuit board structure according to any one of claims 3 to 5, wherein at least one of the chip pins is a second type pin, and the ink window size of the second type pin is less than or equal to the first type pin. Pad size for type 2 pins.
A camera module includes: the circuit board structure according to any one of claims 1 to 6.
An electronic device including: the camera module as claimed in claim 7.
A circuit board structure manufacturing method, applied to the circuit board structure according to any one of claims 1 to 6, wherein the manufacturing method includes:

Obtain a second circuit board in the circuit board structure, and etch inner circuits on the second circuit board;

Superimpose the first circuit board on the first side of the etched second circuit board;

Laminate the stacked first circuit board and second circuit board;

Etching outer circuits on the laminate first circuit board;

After etching the outer layer circuit, drilling through holes is performed on the first circuit board and the second circuit board;

Electroplating the openings on the drilled first circuit board and the second circuit board;

Wherein, the openings on the first circuit board and the second circuit board are connected.
The circuit board structure manufacturing method according to claim 9, wherein the first circuit board is superimposed on the first side of the etched second circuit board, including:

The first insulating layer and the first circuit board are sequentially stacked on the first side of the etched second circuit board.