CN115297604A - Double-layer circuit board structure and welding method thereof - Google Patents

Abstract

The application provides a double-layer circuit board structure and a welding method thereof. The double-layer circuit board structure comprises a bottom board and a core board; a plurality of first bonding pads extending to the side edge of the core board are arranged on the first surface of the core board; a plurality of second bonding pads which correspond to the first bonding pads one to one are arranged on the first surface of the bottom plate; the bottom plate is provided with a hollow structure penetrating through the first surface and the second surface of the bottom plate; a plurality of third bonding pads extending to the side edges of the hollow structure are arranged on the second surface of the bottom plate; a plurality of fourth bonding pads which correspond to the third bonding pads one to one are arranged on the second surface of the core board; when the base plate is welded with the core plate, the second surface of the core plate is attached to the first surface of the base plate; the first bonding pads and the second bonding pads are welded in a one-to-one correspondence mode; and the third bonding pads and the fourth bonding pads are welded in a one-to-one correspondence mode. The double-layer circuit board structure is convenient to weld and high in space utilization rate, and can meet large-scale outgoing line requirements.

Description

Double-layer circuit board structure and welding method thereof

Technical Field

The application relates to the technical field of circuit boards, in particular to a double-layer circuit board structure and a welding method thereof.

Background

With the improvement of semiconductor chip manufacturing processes, the functions provided by chips are increasing, the packaging density of chips is increasing, and the requirements for Printed Circuit Boards (PCBs) are gradually increasing from single-layer boards to multi-layer boards. The most common mode in the industry at present is "core board + bottom plate", wherein, core board generally adopts the circuit board of higher price to make, and its area occupied is less for placing main chip core circuit, and the bottom plate adopts the circuit board of lower price to make, and its area occupied is great, is used for bearing the circuit that most is not high to circuit board technology requirement.

The existing connection mode between the core board and the bottom board generally has the following schemes: 1. the high-speed signal transmission device is connected through the pin header, is low in cost, has large influence on high-speed signals, cannot be used in scenes with the high-speed signals, occupies a large space, and is generally only applied to development boards and products with large space. 2. The connection is performed through an FPC (Flexible Printed Circuit) line, and although the high-speed signal performance can be ensured, the occupied space is large, and the product cannot be miniaturized, and is generally applied only to a development board and a product with a large space. 3. Welding through BGA (Ball Grid Array, globular pin Grid Array) packaging technology, can realizing high pin density, nevertheless owing to involve operations such as planting Ball welding, the cost is higher to because the BGA Ball bears gravity limitedly, can't use on extensive nuclear core plate, in addition, if appear rosin joint scheduling problem, can only use special welding stage to part PCB completely, plant the Ball again and weld again, cost of maintenance is higher. 4. The stamp hole is adopted for packaging and welding, so that the cost is low, the reliability is high, but the space utilization rate of the bottom plate and the core plate is low, the number of the bearing pads is small, and the large-scale wire outlet requirement is difficult to meet.

Disclosure of Invention

In view of the above, the present application is proposed to provide a two-layer circuit board structure and a soldering method thereof that overcomes or at least partially solves the above problems, comprising:

a dual layer circuit board structure comprising: a bottom plate and a core plate; the bottom plate comprises a first surface and a second surface which are oppositely arranged; the core board comprises a first surface and a second surface which are oppositely arranged;

a plurality of first bonding pads are arranged on the first surface of the core board; the first bonding pad extends to the side edge of the core board; a plurality of second bonding pads which correspond to the first bonding pads one to one are arranged on the first surface of the bottom plate;

the bottom plate is provided with a hollow structure penetrating through the first surface and the second surface of the bottom plate; a plurality of third bonding pads are arranged on the second surface of the bottom plate; the third bonding pad extends to the side edge of the hollowed-out structure; a plurality of fourth bonding pads which correspond to the third bonding pads one to one are arranged on the second surface of the core board;

when the base plate is welded with the core plate, the second surface of the core plate is attached to the first surface of the base plate; the first bonding pads and the second bonding pads are welded in a one-to-one correspondence mode; and the third bonding pads and the fourth bonding pads are welded in a one-to-one correspondence mode.

Preferably, a plurality of first notches which correspond to the first bonding pads one to one are formed in the side edge of the core board; the first pad extends to a side of the first recess.

Preferably, the first recess is semi-circular in shape.

Preferably, a plurality of second notches which correspond to the third bonding pads one to one are formed in the side edge of the hollowed-out structure; the third pad extends to a side of the second recess.

Preferably, the second recess is semi-circular in shape.

Preferably, the first surface of the bottom plate is provided with an installation area corresponding to the core plate; the hollow-out structure corresponds to the inside of the mounting area.

Preferably, the first pads are disposed around an edge of the core board.

Preferably, the third pad is arranged around the edge of the hollow structure.

Preferably, the bottom plate, the core plate and the hollow structure are respectively rectangular in shape.

A method of soldering a two-layer circuit board structure as claimed in any one of the preceding claims, comprising:

placing the core board in a mounting area of a first side of the backplane; the second surface of the core board is attached to the first surface of the bottom board;

correspondingly welding the first bonding pads and the second bonding pads one by one;

and turning the base plate and the core plate, and welding the third bonding pads and the fourth bonding pads in a one-to-one correspondence manner to obtain a welded double-layer circuit board structure.

The application has the following advantages:

in the embodiments of the present application, through the backplane and the core board; the bottom plate comprises a first surface and a second surface which are oppositely arranged; the core board comprises a first surface and a second surface which are oppositely arranged; a plurality of first bonding pads are arranged on the first surface of the core board; the first bonding pad extends to the side edge of the core board; a plurality of second bonding pads which correspond to the first bonding pads one to one are arranged on the first surface of the bottom plate; the bottom plate is provided with a hollow structure penetrating through the first surface and the second surface of the bottom plate; a plurality of third bonding pads are arranged on the second surface of the bottom plate; the third bonding pad extends to the side edge of the hollow structure; a plurality of fourth bonding pads which correspond to the third bonding pads one to one are arranged on the second surface of the core board; when the base plate is welded with the core plate, the second surface of the core plate is attached to the first surface of the base plate; the first bonding pads and the second bonding pads are welded in a one-to-one correspondence mode; the third bonding pads and the fourth bonding pads are welded in a one-to-one correspondence mode, the welding cost is low, welding can be achieved only by conventional tin brushing, operations such as tin planting and support bracket addition are not needed, and the requirement on production equipment is low; the reliability is high, the core board is in close contact with the bottom board, and the probability of the insufficient soldering problem is low; the maintainability is high, whether the welding is good or not can be confirmed through visual inspection, if the welding is poor, only a simple tool such as a soldering iron is used for processing a poor point, and a special repair welding table is not needed; space utilization is higher, the bottom plate with the pad that nuclear core plate can bear is in large quantity, can satisfy large-scale the demand of being qualified for the next round of competitions.

Drawings

In order to more clearly illustrate the technical solutions of the present application, the drawings required to be used in the description of the present application will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art that other drawings may be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a double-layer circuit board structure according to an embodiment of the present disclosure;

fig. 2 is a schematic processing diagram (front side) of a double-layer circuit board structure according to an embodiment of the present application;

fig. 3 is a schematic processing diagram (back side) of a double-layer circuit board structure according to an embodiment of the present application;

fig. 4 is a flowchart illustrating steps of a method for soldering a two-layer circuit board structure according to an embodiment of the present disclosure.

The reference numbers in the drawings of the specification are as follows:

10. a base plate; 11. a second bonding pad; 12. a third pad; 13. a hollow structure; 14. a second recess; 20. a core board; 21. a first pad; 22. a fourth pad; 23. a first recess.

Detailed Description

In order to make the objects, features and advantages of the present application more comprehensible, the present application is described in further detail with reference to the accompanying drawings and the detailed description. It should be apparent that the embodiments described are some, but not all embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Referring to fig. 1 to 3, a two-layer circuit board structure provided by an embodiment of the present application is shown, including: a base plate 10 and a core plate 20; wherein the base plate 10 includes a first face and a second face which are oppositely arranged; the core board 20 includes a first surface and a second surface which are oppositely disposed;

a plurality of first bonding pads 21 are arranged on the first surface of the core board 20; the first pads 21 extend to the side of the core board 20; a plurality of second bonding pads 11 which are in one-to-one correspondence with the first bonding pads 21 are arranged on the first surface of the bottom plate 10;

the bottom plate 10 is provided with a hollow structure 13 penetrating through the first surface and the second surface of the bottom plate 10; a plurality of third bonding pads 12 are arranged on the second surface of the bottom plate 10; the third pad 12 extends to the side of the hollow structure 13; a plurality of fourth bonding pads 22 corresponding to the third bonding pads 12 one to one are arranged on the second surface of the core board 20;

when the base plate 10 and the core plate 20 are welded, the second surface of the core plate 20 and the first surface of the base plate 10 are attached to each other; the first bonding pads 21 and the second bonding pads 11 are welded correspondingly one to one; the third bonding pads 12 and the fourth bonding pads 22 are correspondingly welded.

In the embodiment of the present application, the core board 20 is connected to the backplane 10; wherein the base plate 10 includes a first face and a second face which are oppositely arranged; the core board 20 includes a first surface and a second surface opposite to each other; a plurality of first bonding pads 21 are arranged on the first surface of the core board 20; the first pads 21 extend to the side of the core board 20; a plurality of second bonding pads 11 which correspond to the first bonding pads 21 one by one are arranged on the first surface of the bottom plate 10; the bottom plate 10 is provided with a hollow structure 13 penetrating through the first surface and the second surface of the bottom plate 10; a plurality of third bonding pads 12 are arranged on the second surface of the bottom plate 10; the third pad 12 extends to the side of the hollow structure 13; a plurality of fourth bonding pads 22 corresponding to the third bonding pads 12 one to one are arranged on the second surface of the core board 20; when the base plate 10 and the core plate 20 are welded, the second surface of the core plate 20 and the first surface of the base plate 10 are attached to each other; the first bonding pads 21 and the second bonding pads 11 are welded correspondingly one to one; the third bonding pads 12 and the fourth bonding pads 22 are welded in a one-to-one correspondence manner, so that the welding cost is low, the welding can be realized only by conventional tin brushing, operations such as tin planting and additional support bracket are not needed, and the requirement on production equipment is low; the reliability is high, the core board 20 is in close contact with the bottom board 10, and the probability of the insufficient soldering problem is low; the maintainability is high, whether the welding is good or not can be confirmed through visual inspection, if the welding is poor, only a simple tool such as a soldering iron is used for processing a poor point, and a special repair welding table is not needed; space utilization is higher, the bottom plate 10 with the pad quantity that core plate 20 can bear is more, can satisfy large-scale the demand of being qualified for the next round of competitions.

Next, a two-layer circuit board structure in the present exemplary embodiment will be further described.

In this embodiment, a plurality of first notches 23 corresponding to the first pads 21 one to one are formed in the side edge of the core board 20; the first pad 21 extends to the side of the first recess 23. When the base board 10 is soldered to the core board 20, the end of the second pad 11 corresponds to the position of the first notch 23. By providing the first notch 23, tin absorption during tin melting is facilitated, so that the first pad 21 and the second pad 11 are more firmly welded.

In this embodiment, the first notch 23 is shaped as a semi-circle. The first notch 23 is matched with the shape of the molten tin, so that tin can be conveniently eaten during tin melting. In other embodiments, the shape of the first recess 23 may also be trapezoidal, saw-toothed or other irregular shapes.

In this embodiment, a plurality of second notches 14 corresponding to the third pads 12 one to one are formed in the side edge of the hollow structure 13; the third pad 12 extends to the side of the second recess 14. When the base board 10 is soldered to the core board 20, the end of the fourth pad 22 corresponds to the position of the first notch 23. By providing the second notch 14, tin absorption during tin melting is facilitated, so that the third pad 12 and the fourth pad 22 are more firmly welded.

In this embodiment, the second recess 14 is shaped as a semi-circle. The second notch 14 is matched with the shape of the molten tin, so that the tin can be conveniently eaten during tin melting. In other embodiments, the shape of the second recess 14 may also be trapezoidal, saw-toothed or other irregular shapes.

In this embodiment, the first surface of the base plate 10 is provided with an installation area corresponding to the core plate 20; the hollow structure 13 corresponds to the inside of the mounting area. When the base plate 10 is welded to the core plate 20, the core plate 20 covers the hollowed-out area.

In this embodiment, the first pads 21 are disposed around the edge of the core board 20. When the base board 10 is soldered to the core board 20, the second pads 11 surround the edge of the core board 20. By arranging the first bonding pad 21 and the second bonding pad 11 in a surrounding manner, the space utilization rate is improved conveniently, and the large-scale appearance requirement is met.

In one embodiment, the core board 20 has four sides, wherein each side is provided with eleven first pads 21.

In this embodiment, the third pad 12 is disposed around the edge of the hollow structure 13. When the base plate 10 is welded to the core plate 20, the fourth bonding pads 22 surround the edges of the hollow structures 13. By arranging the third pad 12 and the fourth pad 22 in a surrounding manner, the space utilization rate is improved, and the large-scale appearance requirement is met.

In one specific implementation, the hollow structure 13 has four sides, where each side is provided with four third pads 12.

In this embodiment, the bottom plate 10, the core plate 20, and the hollow structures 13 are respectively rectangular. Specifically, the cross section of the base plate 10 is larger than that of the core plate 20; the cross section of the core plate 20 is larger than that of the hollowed-out structure 13; the hollow structure 13 is arranged in the middle of the bottom plate 10; when the bottom plate 10 is welded to the core plate 20, the hollow structures 13 correspond to the middle position of the core plate 20.

Referring to fig. 4, there is shown a method for welding a two-layer circuit board structure according to any one of the above embodiments, which includes:

s110, placing the core board 20 in the mounting area of the first surface of the base board 10; wherein the second surface of the core board 20 and the first surface of the base board 10 are attached to each other;

s120, correspondingly welding the first bonding pads 21 and the second bonding pads 11 one by one;

s130, the base plate 10 and the core plate 20 are turned over, and the third bonding pads 12 and the fourth bonding pads 22 are welded in a one-to-one correspondence mode to obtain a welded double-layer circuit board structure.

The core board 20 is placed in the mounting area of the first surface of the base board 10 as described in step S110.

The core board 20 is placed in the mounting area of the first side of the base board 10 such that the second side of the core board 20 and the first side of the base board 10 are attached to each other. At this time, the first pads 21 correspond to the second pads 11 in position one to one, and the third pads 12 correspond to the fourth pads 22 in position one to one.

In step S120, the first pads 21 and the second pads 11 are soldered in a one-to-one correspondence.

And melting soldering tin at the connection part of the first bonding pad 21 and the second bonding pad 11 so as to electrically weld the first bonding pad 21 and the second bonding pad 11 one by one.

In step S130, the base board 10 and the core board 20 are turned over, and the third pads 12 and the fourth pads 22 are soldered in a one-to-one correspondence manner, so as to obtain a soldered double-layer circuit board structure.

The base board 10 and the core board 20 are turned over, and solder is melted into the joints of the third pads 12 and the fourth pads 22 to electrically weld the third pads 12 and the fourth pads 22 one by one, so that the welded double-layer circuit board structure is obtained.

While preferred embodiments of the present application have been described, additional variations and modifications of these embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including the preferred embodiment and all changes and modifications that fall within the true scope of the embodiments of the present application.

Finally, it should also be noted that, in this document, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrases "comprising one of 8230; \8230;" 8230; "does not exclude the presence of additional like elements in a process, method, article, or terminal device that comprises the element.

The above detailed description is provided for a double-layer circuit board structure and a welding method thereof, and the principle and the implementation of the present application are explained by applying specific examples, and the description of the above examples is only used to help understanding the method and the core idea of the present application; meanwhile, for a person skilled in the art, according to the idea of the present application, the specific implementation manner and the application scope may be changed, and in summary, the content of the present specification should not be construed as a limitation to the present application.

Claims (10)

1. A two-layer circuit board structure, comprising: the core board is arranged on the bottom board; the bottom plate comprises a first surface and a second surface which are oppositely arranged; the core board comprises a first surface and a second surface which are oppositely arranged;

a plurality of first bonding pads are arranged on the first surface of the core board; the first bonding pad extends to the side edge of the core board; a plurality of second bonding pads which correspond to the first bonding pads one to one are arranged on the first surface of the bottom plate;

the bottom plate is provided with a hollow structure penetrating through the first surface and the second surface of the bottom plate; a plurality of third bonding pads are arranged on the second surface of the bottom plate; the third bonding pad extends to the side edge of the hollowed-out structure; a plurality of fourth bonding pads which correspond to the third bonding pads one to one are arranged on the second surface of the core board;

when the base plate is welded with the core plate, the second surface of the core plate is attached to the first surface of the base plate; the first bonding pads and the second bonding pads are welded in a one-to-one correspondence mode; and the third bonding pads and the fourth bonding pads are welded in a one-to-one correspondence mode.

2. The double-layer circuit board structure of claim 1, wherein the side of the core board is provided with a plurality of first notches corresponding to the first bonding pads one to one; the first pad extends to a side of the first recess.

3. The two-layer circuit board structure of claim 2, wherein the first recess is semi-circular in shape.

4. The double-layer circuit board structure of claim 1, wherein the side of the hollow structure is provided with a plurality of second notches corresponding to the third bonding pads one to one; the third pad extends to a side of the second recess.

5. The two-layer circuit board structure of claim 4, wherein the second recess is semi-circular in shape.

6. The two-layer circuit board structure of claim 1, wherein the first side of the base board is provided with a mounting area corresponding to the core board; the hollow-out structure corresponds to the inside of the mounting area.

7. The two-layer circuit board structure of claim 6, wherein the first bond pad is disposed around an edge of the core board.

8. The double-layer circuit board structure of claim 6, wherein the third bonding pad is disposed around an edge of the hollow structure.

9. The double-layer circuit board structure of claim 1, wherein the bottom board, the core board and the hollowed-out structure are respectively rectangular in shape.

10. A method of soldering a two-layer circuit-board structure according to any one of claims 1-9, comprising:

placing the core board in a mounting area of a first side of the backplane; the second surface of the core board is attached to the first surface of the bottom board;

correspondingly welding the first bonding pads and the second bonding pads one by one;

and turning the base plate and the core plate, and welding the third bonding pads and the fourth bonding pads in a one-to-one correspondence manner to obtain a welded double-layer circuit board structure.

Images