阅读说明：本技术 一种电路板及其制造方法、封装件 (Circuit board, manufacturing method thereof and packaging piece ) 是由 郭进良 于 2021-09-27 设计创作，主要内容包括：本申请提供一种电路板及其制造方法、封装件。电路板包括：第一介电层,所述第一介电层设置有多个第一导电孔；第二介电层,叠设在所述第一介电层上,所述第二介电层远离所述第一介电层的表面上设置有多个焊盘；针对所述多个焊盘中的任意一个焊盘,该焊盘与各个所述第一导电孔均错开设置。该电路板的可靠性较高。(The application provides a circuit board, a manufacturing method thereof and a packaging piece. The circuit board includes: a first dielectric layer provided with a plurality of first conductive holes; the second dielectric layer is stacked on the first dielectric layer, and a plurality of bonding pads are arranged on the surface, far away from the first dielectric layer, of the second dielectric layer; for any one of the pads, the pad is staggered with each first conductive hole. The reliability of the circuit board is high.)

1. A circuit board, comprising:

a first dielectric layer provided with a plurality of first conductive holes;

the second dielectric layer is stacked on the first dielectric layer, and a plurality of bonding pads are arranged on the surface, far away from the first dielectric layer, of the second dielectric layer;

for any one of the pads, the pad is staggered with each first conductive hole.

2. The circuit board of claim 1, wherein the second dielectric layer is further provided with second conductive holes corresponding to the pads, and the diameter of each second conductive hole is smaller than that of the first conductive hole; a circuit layer is formed between the first dielectric layer and the second dielectric layer; at least part of the bonding pad is in signal conduction with the first conductive hole through the second conductive hole and the circuit layer corresponding to the bonding pad.

3. The circuit board of claim 1, wherein the pad and the first conductive via have no overlapping portion in an orthogonal projection on the same projection plane.

4. The circuit board of claim 1, wherein when a solder ball is formed on each of the plurality of pads to form a ball grid array for soldering a chip, a size of the ball grid array is greater than a preset size.

5. The circuit board of claim 4, wherein the predetermined dimensions are: 5MM by 5 MM.

6. A package, comprising:

the circuit board of any one of claims 1-5;

and the chip is electrically connected with the circuit board through the plurality of bonding pads.

7. The package of claim 6, wherein a solder ball is formed on each of the pads, the chip is electrically connected to the pad through the solder ball, and is electrically connected to the circuit board through a corresponding pad of the pads, and a filler is disposed in a gap between the solder balls at a connection position of the corresponding pad and the chip.

8. A method of manufacturing a circuit board, comprising:

obtaining a first dielectric layer and a second dielectric layer;

forming a plurality of first conductive holes in the first dielectric layer;

laminating the second dielectric layer on the first dielectric layer on which the first conductive hole is formed;

forming a plurality of pads on a surface of the second dielectric layer remote from the first dielectric layer; for any one of the pads, the pad is staggered with each first conductive hole.

9. The manufacturing method according to claim 8, wherein before the second dielectric layer is laminated on the first dielectric layer on which the first conductive hole is formed, the manufacturing method further comprises:

forming a circuit layer on one surface of the first dielectric layer, wherein the circuit layer is electrically connected with the first conductive hole;

correspondingly, the step of laminating the second dielectric layer on the first dielectric layer formed with the first conductive hole comprises the following steps:

and laminating the second dielectric layer on one side of the first dielectric layer where the circuit layer is formed, so that the circuit layer is positioned between the first dielectric layer and the second dielectric layer.

10. The manufacturing method according to claim 9, wherein after the laminating the second dielectric layer on the side of the first dielectric layer on which the wiring layer is formed, the manufacturing method further comprises:

forming a plurality of second conductive holes in the second dielectric layer, wherein the aperture of the second conductive holes is smaller than that of the first conductive holes, the second conductive holes are staggered with the first conductive holes, and the second conductive holes are electrically connected with the circuit layer;

accordingly, forming a plurality of pads on a surface of the second dielectric layer remote from the first dielectric layer comprises: and forming a plurality of bonding pads corresponding to the second conductive holes on the surface of the second dielectric layer far away from the first dielectric layer, so that at least part of the bonding pads are in signal conduction with the first conductive holes through the second conductive holes and the circuit layer corresponding to the bonding pads.

Technical Field

The present disclosure relates to the field of electronic circuit technologies, and in particular, to a circuit board, a method for manufacturing the circuit board, and a package.

Background

In electronic Circuit products, a Printed Circuit Board (PCB) is used, and BGA (Ball Grid Array) is a common packaging method for PCB.

However, the conventional BGA package has a problem of solder ball cracking, which results in low reliability of the circuit board and even affects the product function.

Disclosure of Invention

An object of the present invention is to provide a circuit board, a method for manufacturing the same, and a package, so as to improve reliability of the circuit board.

In a first aspect, an embodiment of the present application provides a circuit board, including: a first dielectric layer provided with a plurality of first conductive holes; the second dielectric layer is stacked on the first dielectric layer, and a plurality of bonding pads are arranged on the surface, far away from the first dielectric layer, of the second dielectric layer; for any one of the pads, the pad is staggered with each first conductive hole.

In the embodiment of the application, the reason that the solder balls crack existing in the conventional BGA package is analyzed, and it is determined that the reason that the solder balls crack is that the distribution of the conductive holes inside the circuit board has no special requirement, and the distribution positions of the conductive holes correspond to the distribution positions of the bonding pads, so that the solder balls on the bonding pads corresponding to the conductive holes crack due to the stress existing at the conductive holes in the soldering process. Based on the problem that prior art exists, stagger in the distribution position through the distribution position with the electrically conductive hole and the distribution position of pad in the space in this application embodiment, avoid the stress of electrically conductive hole department to cause the influence to the pad in the welding process, and then avoid the solder ball to split, improve the reliability of circuit board.

As a possible implementation manner, second conductive holes corresponding to the pads are further disposed on the second dielectric layer, and the aperture of each second conductive hole is smaller than that of each first conductive hole; a circuit layer is formed between the first dielectric layer and the second dielectric layer; at least part of the bonding pad is in signal conduction with the first conductive hole through the second conductive hole and the circuit layer corresponding to the bonding pad.

In the embodiment of the application, through the second conductive hole arranged on the second dielectric layer and the circuit layer between the first dielectric layer and the second dielectric layer, signal conduction between at least part of the bonding pad and the first conductive hole is realized, and the normal function of the circuit board is ensured.

As a possible implementation manner, the orthographic projection of the pad and the first conductive hole on the same plane has no overlapped part.

In the embodiment of the application, when the orthographic projections of the bonding pad and the first conductive hole on the same plane do not have the overlapped part, the bonding pad and the first conductive hole can be fully ensured to be staggered in space, and the reliability of the circuit board is further improved.

As a possible implementation, when a solder ball is formed on each of the plurality of pads to form a ball grid array for soldering a chip, a size of the ball grid array is larger than a preset size.

In the embodiment of the application, when the solder ball is formed on each of the plurality of pads to form the ball grid array for welding the chip, the possibility of cracking is higher when the size of the ball grid array is larger than the preset size, therefore, the distribution position is staggered for the situation, and the reliability of the circuit board can be improved.

As a possible implementation manner, the preset sizes are: 5MM by 5 MM.

In the embodiment of the present application, the reliability of the circuit board can be improved by limiting the preset size by 5 × 5 MM.

In a second aspect, an embodiment of the present application provides a package, including: the circuit board as described in the first aspect and any one of the possible implementations of the first aspect; and the chip is electrically connected with the circuit board through the plurality of bonding pads.

In the embodiment of the present application, by applying the circuit board of the first aspect to the package, the reliability of the circuit board is improved, and the stability of the product function of the package is also improved.

As a possible implementation manner, a solder ball is formed on each of the plurality of pads, the chip is electrically connected to the pad through the solder ball to be electrically connected to the circuit board, and a gap between the solder balls is provided with a filler.

In the embodiment of the application, the filler is arranged in the gap between the solder balls, so that the physical connection reliability between the circuit board and the chip is improved, and the stability of the packaging piece is further improved.

In a third aspect, an embodiment of the present application provides a method for manufacturing a circuit board, including: obtaining a first dielectric layer and a second dielectric layer; forming a plurality of first conductive holes in the first dielectric layer; laminating the second dielectric layer on the first dielectric layer on which the first conductive hole is formed; forming a plurality of pads on a surface of the second dielectric layer remote from the first dielectric layer; for any one of the pads, the pad is staggered with each first conductive hole.

In the embodiment of the present application, in combination with the analysis of the prior art in the foregoing first aspect, when the circuit board is manufactured, the distribution positions of the conductive holes and the distribution positions of the pads are staggered in space, so that the stress generated at the conductive holes during the soldering process is prevented from affecting the pads, further, the solder balls are prevented from cracking, and the reliability of the circuit board is improved.

As one possible implementation, before the second dielectric layer is stacked on the first dielectric layer on which the first conductive hole is formed, the manufacturing method further includes: forming a circuit layer on one surface of the first dielectric layer, wherein the circuit layer is electrically connected with the first conductive hole; correspondingly, the step of laminating the second dielectric layer on the first dielectric layer formed with the first conductive hole comprises the following steps: and laminating the second dielectric layer on one side of the first dielectric layer where the circuit layer is formed, so that the circuit layer is positioned between the first dielectric layer and the second dielectric layer.

As a possible implementation manner, after the laminating the second dielectric layer on the side of the first dielectric layer on which the line layer is formed, the manufacturing method further includes: forming a plurality of second conductive holes in the second dielectric layer, wherein the aperture of the second conductive holes is smaller than that of the first conductive holes, the second conductive holes are staggered with the first conductive holes, and the second conductive holes are electrically connected with the circuit layer; accordingly, forming a plurality of pads on a surface of the second dielectric layer remote from the first dielectric layer comprises: and forming a plurality of bonding pads corresponding to the second conductive holes on the surface of the second dielectric layer far away from the first dielectric layer, so that at least part of the bonding pads are in signal conduction with the first conductive holes through the second conductive holes and the circuit layer corresponding to the bonding pads.

In the embodiment of the application, the second conductive hole is formed in the second dielectric layer, and the circuit layer is formed between the first dielectric layer and the second dielectric layer, so that signal conduction between at least part of the pad and the first conductive hole is realized, and the basic function of the circuit board is ensured.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and that those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.

Fig. 1 is a schematic structural diagram of a circuit board provided in an embodiment of the present application;

FIG. 2 is a schematic diagram of a first dielectric layer provided in an embodiment of the present application;

FIG. 3 is a schematic diagram of a second dielectric layer provided in accordance with an embodiment of the present application;

FIG. 4 is a diagram illustrating a first example projection of a staggered arrangement according to an embodiment of the present application;

FIG. 5 is a diagram illustrating a second example projection of a staggered arrangement according to an embodiment of the present application;

fig. 6 is a schematic structural diagram of a package provided in an embodiment of the present application;

fig. 7 is a flowchart of a method for manufacturing a circuit board according to an embodiment of the present application.

Icon: 100-a circuit board; 110-a first dielectric layer; 111-a first conductive via; 120-a second dielectric layer; 121-pad; 600-a package; 610-chip.

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application.

The technical scheme provided by the embodiment of the application can be applied to a PCB (printed circuit board), and the PCB adopts BGA (Ball Grid Array) packaging, namely, each welding pad on the PCB forms a Ball Grid Array.

Referring to fig. 1, a schematic structural diagram of a circuit board 100 according to an embodiment of the present disclosure is provided, and the schematic structural diagram may be understood as a portion of the circuit board 100 and does not represent the entire circuit board 100.

In fig. 1, the circuit board 100 includes a first dielectric layer 110 and a second dielectric layer 120, and the first dielectric layer 110 and the second dielectric layer 120 are stacked.

In practical applications, the circuit board 100 may further include a third dielectric layer and a fourth dielectric layer, or even more. Further, the circuit board 100 may include more dielectric layers disposed according to the arrangement of the first dielectric layer 110 and the second dielectric layer 120.

Referring to fig. 2, which is a schematic structural view of the first dielectric layer 110, a plurality of first conductive vias 111 are disposed on the first dielectric layer 110. As for the first conductive hole 111, it may be formed as follows. Firstly, drilling a first dielectric layer 110 to form a first through hole, wherein the first through hole penetrates through two opposite surfaces of the first dielectric layer 110; then, a conductive material (e.g., copper, aluminum, etc.) is plated on the wall of the first via hole, so as to obtain the first conductive via 111.

Referring to fig. 3, which is a schematic structural diagram of the second dielectric layer 120, a plurality of pads 121 are disposed on the second dielectric layer 120, and a surface of the pads 121 is a surface of the second dielectric layer 120 away from the first dielectric layer 110. The plurality of pads 121 may be formed by a conventional manufacturing process of a circuit board such as exposure, development, etching, and the like.

Wherein, for any one pad 121 in the plurality of pads 121, the pad 121 is staggered with each first conductive hole 111.

It should be understood that the plurality of pads 121 may be only a portion of the pads 121 on the second dielectric layer 120, or only a portion of the pads 121 on the circuit board 100, or the plurality of pads 121 may be the pads 121 that need to be staggered.

In addition, the solder balls corresponding to the plurality of pads 121 are formed in a ball grid array based on the BGA package method employed by the circuit board 100.

By analyzing the cause of the cracking of the solder balls in the conventional BGA package, it is determined that the cause of the cracking of the solder balls is that the distribution of the conductive holes in the circuit board 100 has no special requirement, and the distribution positions of the conductive holes correspond to the distribution positions of the pads 121, so that the solder balls on the corresponding pads are cracked due to the stress existing at the conductive holes in the soldering process. Based on the problems existing in the prior art, the distribution positions of the conductive holes and the distribution positions of the bonding pads 121 are staggered in space in the embodiment of the application, so that the stress at the conductive holes in the welding process is prevented from influencing the bonding pads, the cracking of the solder balls is avoided, and the reliability of the circuit board is improved.

The pad 121 and the first conductive via 111 are staggered to prevent stress of the first conductive via 111 from affecting the pad 121. In some embodiments, the pad 121 and the first conductive via 111 have no overlapping portion in an orthogonal projection on the same plane.

For easy understanding, please refer to fig. 4, which is a schematic orthographic projection view of the pad 121 and the first conductive via 111 on the same plane, and as can be seen from fig. 4, the projections of the pad 121 and the first conductive via 111 do not overlap at all.

In the embodiment of the present application, when the orthographic projections of the pad 121 and the first conductive via 111 on the same plane do not have an overlapping portion, the misalignment between the pad 121 and the first conductive via 111 can be sufficiently ensured, and the reliability of the circuit board 100 can be further improved.

In other embodiments, the orthographic projection of the pad 121 and the first conductive via 111 on the same plane may have an overlapping portion, but the overlapping portion has an area smaller than a predetermined area, wherein the predetermined area may be determined by a smaller projected area of the pad 121 and the projected area of the first conductive via 111. For example: the preset area may be one quarter, one fifth, or even less than the smaller projected area.

For easy understanding, please refer to fig. 5, which is a schematic orthographic projection diagram of the pad 121 and the first conductive via 111 on the same projection plane, and as can be seen from fig. 5, there is a partial overlap between the orthographic projections of the pad 121 and the first conductive via 111, but the overlapping area is small, and the influence of the stress on the pad 121 can be avoided to some extent.

For the first dielectric layer 110 and the second dielectric layer 120, whether they are part of the circuit board 100 or the circuit board 100 only includes these two dielectric layers, the pad 121 on the second dielectric layer 120 needs to be in signal communication with the first conductive via 111, so that the normal function of the circuit board 100 can be ensured.

Therefore, as an alternative embodiment, on the second dielectric layer 120, second conductive holes corresponding to the pads 121 are further provided, and the diameter of the second conductive holes is smaller than that of the first conductive holes 111. And, a wiring layer is formed between the first dielectric layer 110 and the second dielectric layer 120.

For at least a part of the pads 121 that need to be electrically connected to the first conductive vias 111, signals are electrically connected to the first conductive vias 111 through the corresponding second conductive vias and the aforementioned circuit layer.

In the embodiment of the present application, the second conductive via disposed on the second dielectric layer 120 and the circuit layer between the first dielectric layer 110 and the second dielectric layer 120 are used to realize signal conduction between at least a portion of the pad 121 and the first conductive via 111, so as to ensure normal functions of the circuit board 100.

It is understood that when a solder ball is formed on each of the plurality of pads 121 to form a ball grid array for chip bonding, if the size of the ball grid array is small, stress is small even if stress is generated, and the solder ball is not cracked at this time; if the size of the ball grid array is larger, the corresponding stress is also larger, resulting in a higher possibility of cracking the solder balls.

Therefore, as an alternative embodiment, when a solder ball is formed on each of the plurality of pads 121 to form a ball grid array for soldering a chip, the size of the ball grid array is larger than a preset size.

In the embodiment of the present application, when a solder ball is formed on each of the plurality of pads 121 to form a ball grid array for chip bonding, there is a high possibility of a crack problem in the case where the size of the ball grid array is larger than a preset size, and therefore, the reliability of the circuit board 100 can be improved by performing the staggered arrangement of the distribution positions for such a case.

The preset size may be set according to a size of a ball grid array formed by solder balls corresponding to the plurality of pads 121 in case that some solder balls are cracked in practical application. For example: according to the analysis of the cracking condition of some existing solder balls, when the size of the ball grid array is larger than a certain specific size, the solder balls are basically cracked; the preset size may be the specific size.

As an alternative embodiment, the preset sizes are: 5MM by 5 MM.

In the embodiments of the present application, it is found from practical application results that, when the size of the ball grid array is less than 5 × 5MM, there is no problem of solder ball cracking, and when the size is larger than that, solder ball cracking easily occurs. Therefore, the reliability of the circuit board 100 can be improved by limiting the preset size to 5 × 5 MM.

With reference to the foregoing description of the embodiment of the circuit board 100, next, referring to fig. 6, a schematic structural diagram of a package 600 provided in an embodiment of the present application is shown, where the package 600 includes: a circuit board 100 and a chip 610, the chip 610 being electrically connected to the circuit board 100 through a plurality of pads 121.

In the embodiment of the present application, by applying the circuit board 100 to the package 600, the stability of the product function of the package 600 is improved on the basis of the improvement of the reliability of the circuit board 100.

The chip 610 may be a chip 610 of various products, including a main control chip 610, or a chip 610 with various functions.

As an alternative embodiment, a solder ball is formed on each of the pads 121 in the plurality of pads 121, the chip 610 is electrically connected to the pads 121 through the solder ball to be electrically connected to the circuit board 100, and a gap between the solder balls is provided with a filler.

The material of the filler can be some common filler materials, such as: silica gel, molding compound, etc., which are not limited in the embodiments of the present application.

In the embodiment of the application, the filler is disposed in the gap between the solder balls, so that the reliability of the electrical connection between the circuit board 100 and the chip 610 is improved, and the stability of the package 600 is further improved.

With reference to the foregoing description of the embodiment of the circuit board 100, and referring to fig. 7, the present application further provides a method for manufacturing the circuit board 100, where the method is applicable to manufacturing the circuit board 100, and the method includes:

step 710: a first dielectric layer 110 and a second dielectric layer 120 are obtained.

Step 720: a plurality of first conductive holes 111 are formed in the first dielectric layer 110.

Step 730: the second dielectric layer 120 is stacked on the first dielectric layer 110 formed with the first conductive via 111.

Step 740: a plurality of pads 121 are formed on the surface of the second dielectric layer 120 remote from the first dielectric layer 110. For any one pad 121 of the plurality of pads 121, the pad 121 is offset from each of the first conductive vias 111.

In the embodiment of the present application, in combination with the foregoing analysis of the prior art, when the circuit board 100 is manufactured, and when the circuit board 100 is manufactured, the distribution positions of the conductive holes and the distribution positions of the pads 121 are staggered in space, so that the stress generated at the conductive holes during the soldering process is prevented from affecting the pads 121, and further, the solder balls are prevented from cracking, and the reliability of the circuit board is improved.

Embodiments of the various steps are described next.

In step 710, the obtained first dielectric layer 110 and the second dielectric layer 120 are the first dielectric layer 110 and the second dielectric layer 120 manufactured by other processes. The manufacture of the dielectric layer in the manufacturing process of the circuit board 100 is well-established and will not be described in detail herein.

In step 720, embodiments of forming a plurality of first conductive vias 111 on the first dielectric layer 110 are described in the previous embodiments.

In step 730, the first dielectric layer 110 and the second dielectric layer 120 with the first conductive holes 111 opened are stacked. In the stacking arrangement, if the first dielectric layer 110 and the second dielectric layer 120 have the same size, the stacking arrangement is performed after aligning the edges; if the first dielectric layer 110 and the second dielectric layer 120 have different sizes, it is ensured that at least one edge thereof is aligned, and then stacking is performed to ensure the final stacking effect.

In step 740, a plurality of pads 121 are formed on a surface of the second dielectric layer 120 remote from the first dielectric layer 110. The formation of the plurality of pads 121 can be realized by using a technology mature in the art, and the arrangement positions of the plurality of pads 121 need to be arranged in combination with the positions of the first conductive holes 111.

In the embodiment of the present application, the pads 121 need to be arranged offset from the first conductive vias 111, and for the offset embodiment, reference is made to the description of the offset embodiment in the foregoing embodiment, and the description is not repeated here.

In the embodiment of the present application, when the circuit board 100 is manufactured, the distribution positions of the conductive holes and the distribution positions of the pads 121 are staggered, so that the generated stress is prevented from affecting the pads 121, further, the solder balls are prevented from cracking, and the reliability of the finally manufactured circuit board 100 is improved.

In combination with the description of the foregoing embodiment, in order to ensure the normal function of the circuit board 100, the manufacturing method further includes: forming a circuit layer on a surface of the first dielectric layer 110, the circuit layer being electrically connected to the first conductive via 111; accordingly, step 740 includes: the second dielectric layer 120 is stacked on the side of the first dielectric layer 110 where the circuit layer is formed, so that the circuit layer is located between the first dielectric layer 110 and the second dielectric layer 120.

The embodiment of forming the circuit layer on the dielectric layer may be implemented by using techniques mature in the art, and will not be described in detail in the embodiments of the present application.

After the second dielectric layer 120 is stacked on the side of the first dielectric layer 110 where the circuit layer is formed, the manufacturing method further includes: forming a plurality of second conductive holes in the second dielectric layer 120, wherein the aperture of the second conductive holes is smaller than that of the first conductive holes 111, the second conductive holes are staggered with the first conductive holes 111, and the second conductive holes are electrically connected with the circuit layer; accordingly, forming a plurality of pads 121 on a surface of the second dielectric layer 120 remote from the first dielectric layer 110 includes: a plurality of pads 121 are formed on the surface of the second dielectric layer 120 away from the first dielectric layer 110 corresponding to the second conductive holes, so that at least some of the pads 121 are in signal communication with the first conductive holes 111 through the corresponding second conductive holes and the corresponding circuit layer.

And, the opening of the second conductive hole refers to the opening of the first conductive hole 111, and will not be described again.

The arrangement of the circuit layer may be implemented by the general techniques of the embodiments of the present application, and will not be described in detail here.

In the embodiment of the present application, by forming the second conductive hole on the second dielectric layer 120 and forming the circuit layer between the first dielectric layer 110 and the second dielectric layer 120, signal conduction between at least a portion of the pad 121 and the first conductive hole 111 is achieved, and the basic function of the circuit board 100 is ensured.

In addition, in combination with the description of the foregoing embodiment, it is necessary to consider that the plurality of pads 121 are arranged in a staggered manner, and the size of the ball grid array formed by the corresponding solder balls is larger than a preset size, wherein the implementation of the preset size is described with reference to the description of the foregoing embodiment, and the description is not repeated here.

It is understood that, in the manufacturing flow of the circuit board 100, there should be other basic manufacturing steps besides the above steps, and they are not described in the embodiments of the present application.

In this document, relational terms such as first and second, and the like may be 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.

The above description is only an example of the present application and is not intended to limit the scope of the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.