CN215581882U - Shielding substrate and circuit board - Google Patents

Abstract

The application provides a shielding substrate and a circuit board; wherein, shielding base plate includes: the shielding structure comprises a substrate, wherein a plurality of shielding cavities are formed in the substrate, penetrate through two opposite surfaces of the substrate and are made of non-metal materials; and the metal shielding layer is arranged around the periphery of each shielding cavity. According to the shielding substrate and the circuit board, the situation that a finished circuit board is warped when passing through a reflow soldering part can be avoided, and smooth part pasting can be guaranteed; in addition, the processing cost of the shield substrate can be reduced.

Description

Shielding substrate and circuit board

Technical Field

The application relates to the technical field of communication, in particular to a shielding substrate and a circuit board.

Background

With the development of communication technology, the internet technology of low-orbit satellite communication capable of realizing global coverage enables everything to be interconnected, the low-orbit satellite communication needs to realize the transmission, transmission and reception of signals among satellites, ground receiving stations and terminal users, in order to ensure the stability and integrity of signal transmission, a radar antenna is usually needed to be used for realization, and a phased array radar antenna PCB (Printed Circuit Board) integrating the function of the radar antenna and a common multilayer Printed Circuit Board (PCB) is an important component part of signal transmission in a low-orbit satellite chain system at present.

In the correlation technique, phased array radar antenna PCB board mainly comprises three parts, and a multiply wood, a cavity shielding substrate and a single-sided board of metal material are equipped with the shielding chamber on the cavity shielding substrate of metal material, all are equipped with the signal unit on the mixed single-sided board of multiply wood, and multiply wood and single-sided board are in the middle of the cavity shielding substrate pressfitting of metal material, and the signal unit is located the shielding intracavity.

However, when the finished board in the related art is subjected to reflow soldering, the multilayer board and/or the single-sided board are easily warped, and the situation that the finished board cannot be attached occurs.

SUMMERY OF THE UTILITY MODEL

The application provides a shielding substrate and a circuit board, which can avoid the situation that a finished circuit board is warped when passing through a reflow soldering part and can ensure smooth part pasting; in addition, the processing cost of the shield substrate can be reduced.

According to a first aspect of the present application, there is provided a shield substrate including:

the shielding structure comprises a substrate, wherein a plurality of shielding cavities are formed in the substrate, penetrate through two opposite surfaces of the substrate and are made of non-metal materials;

and the metal shielding layer is arranged around the periphery of each shielding cavity.

In a possible design, a plurality of shielding holes are disposed around the periphery of the shielding cavity, the shielding holes penetrate through two opposite surfaces of the substrate, and the metal shielding layer is disposed in the shielding holes.

In a possible design, the metal shielding layer is located on an inner wall of the shielding hole and has a thickness of 20-26 μm.

In a possible design, the shielding substrate further includes a filling member, and the filling member is filled in the shielding hole.

In a possible design, the shielding hole is the round hole, and is a plurality of the shielding hole be annular array arrange in shielding chamber periphery, the aperture of shielding hole is 0.25 ~ 0.5mm, and is adjacent the hole interval of shielding hole is 0.5 ~ 2.0 mm.

In one possible embodiment, the minimum distance between the edge of the shielding hole and the edge of the shielding cavity is greater than or equal to 0.5 mm.

In a possible design, the shielding hole is a strip-shaped hole, and the strip-shaped hole is discontinuously surrounded on the periphery of the shielding cavity.

In one possible design, the metal shielding layer is located on an inner wall of the shielding cavity around the circumference.

According to a second aspect of the present application, there is provided a circuit board comprising a first sub-board, a second sub-board and a shielding substrate provided in any one of the possible designs of the first aspect of the present application;

the shielding substrate is arranged between the first daughter board and the second daughter board, and the shielding substrate is provided with a plurality of first signal units and a plurality of second signal units, wherein the first signal units and the second signal units are in one-to-one correspondence with a plurality of shielding cavities on the shielding substrate.

In one possible embodiment, the circuit board further includes:

the first bonding layer is positioned between the first sub-board and the shielding substrate and is used for connecting the first sub-board and the shielding substrate;

and the second bonding layer is positioned between the second sub-board and the shielding substrate and is used for connecting the second sub-board and the shielding substrate.

According to the shielding substrate, the circuit board, the manufacturing method of the shielding substrate and the manufacturing method of the circuit board provided by the embodiment of the application; the shielding substrate is made of a non-metal material, a plurality of shielding cavities penetrating through two opposite surfaces of the substrate are formed in the substrate, and a metal shielding layer is arranged around the shielding cavities. Therefore, after the shielding substrate is attached to the daughter board (a multilayer board or a single-sided board) provided with the signal unit, the thermal expansion coefficient of the substrate is close to that of the daughter board due to the fact that the substrate is made of the non-metal material, when reflow soldering is conducted to attach the parts, the situation of warping cannot occur, and smooth attaching of the parts can be guaranteed.

The construction of the present application and other objects and advantages thereof will be apparent from the following detailed description taken in conjunction with the accompanying drawings.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

Fig. 1 is a front view of a first example of a shield substrate provided by an embodiment of the present application;

FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1;

fig. 3 is a cross-sectional view of a second example of a shielding substrate provided by an embodiment of the present application;

fig. 4 is a front view of a third example of a shield substrate provided by an embodiment of the present application;

fig. 5 is a cross-sectional view of a fourth example of a shield substrate provided in an embodiment of the present application;

FIG. 6 is a schematic diagram of an overall structure of a circuit board provided in an embodiment of the present application;

fig. 7 is an exploded schematic view of a circuit board according to an embodiment of the present disclosure;

FIG. 8 is a schematic structural view of a first adhesive layer or a second adhesive layer in an embodiment of the present application;

fig. 9 is a partial enlarged view at B in fig. 6.

Description of reference numerals:

1-a shield substrate; 2-a first daughter board; 3-a second daughter board; 4-a first adhesive layer; 5-a second adhesive layer;

10-a substrate; 20-a metal shielding layer; 30-filling element

11-a shielded cavity; 12-a shielding hole; 13-a metal ring;

201-a first signal unit; 301-a second signal unit; 401-open pore.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. 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.

In the description of the embodiments of the present application, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can include, for example, fixed connections, removable connections, or integral parts; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description of the present application, it is to be understood that the terms "inner," "outer," "upper," "bottom," "front," "back," and the like, when used in the orientation or positional relationship indicated in FIG. 1, are used solely for the purpose of facilitating a description of the present application and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be considered as limiting the present application.

According to the first aspect of the present application, referring to fig. 1 and fig. 2, fig. 1 is a front view of a first example of a shielding substrate provided by the embodiment of the present application, and fig. 2 is a cross-sectional view taken along a line a-a in fig. 1.

The embodiment of the first aspect of the present application provides a shielding substrate 1, including:

the substrate 10 is provided with a plurality of shielding cavities 11 on the substrate 10, and the shielding cavities 11 penetrate through two opposite surfaces of the substrate 10.

Specifically, in the embodiment of the present application, the substrate 10 is made of a non-metal material, such as epoxy resin or a high polymer material with a thermal expansion coefficient similar to or similar to that of epoxy resin.

The shielding cavity 11 may be formed by drilling, slotting, routing, or the like on the surface of the substrate 10. In a specific example, each shielding cavity 11 may be a square cavity with a length and a width of 11mm, that is, each shielding cavity 11 is a cavity with a length of 11 × 11 mm.

And the metal shielding layer 20 is arranged around each shielding cavity 11.

Specifically, in the embodiment of the present application, the metal shielding layer 20 may be a copper layer, a gold layer, a silver layer, an aluminum foil layer, and the like, and the embodiment of the present application does not limit the specific material of the metal shielding layer. The metal shielding layer 20 may be disposed around a circumference of each shielding cavity 11, that is, the metal shielding layer 20 may be a plurality of annular shielding rings, and the arrangement of the plurality of shielding rings is the same as the arrangement of the shielding cavities 11, for example, the shielding rings are arranged on the substrate 10 in an array.

According to the embodiment of the application, the shielding substrate is made of a substrate 10 made of a non-metal material, a plurality of shielding cavities 11 penetrating through two opposite surfaces of the substrate 10 are formed in the substrate 10, and a metal shielding layer 20 is arranged around the shielding cavities 11. Thus, after the shielding substrate 1 is attached to a daughter board (a multilayer board or a single-sided board) provided with a signal unit, since the substrate 10 is made of a non-metal material, the thermal expansion coefficient of the substrate 10 is close to that of the daughter board, and when reflow soldering is performed for attaching a part, the situation of warping does not occur, and smooth attaching of the part can be ensured.

In addition, since the substrate 10 made of a non-metal material is used as a base material of the shield substrate 1, the consumption cost of the used processing tool and the processing tool is reduced compared with the existing metal shield substrate when the substrate 10 is processed, the cost is only 30% of that of the metal shield substrate, and the production cost can be saved.

Alternatively, referring to fig. 1, in the embodiment of the present application, a plurality of shielding holes 12 are disposed around the outer periphery of the shielding cavity 11, the plurality of shielding holes 12 penetrate through two opposite surfaces of the substrate 10, and the metal shielding layer 20 is disposed in the shielding holes 12.

Specifically, in the embodiment of the present application, the metal shielding layer 20 may be attached to the inner wall of the shielding hole 12. For example, adhered to the inner wall of the shielding hole 12 by an adhesive.

In some specific examples, the metal shielding layer 20 may be formed on the inner wall of the shielding hole 12 by chemical deposition and electroplating, for example, a metal copper layer may be deposited on the inner wall of the shielding hole 12 by chemical deposition, and then the copper layer may be thickened by electroplating, so as to form the metal shielding layer 20.

In the embodiment of the present application, the thickness (e.g., the distance D2 in fig. 2) of the metal shielding layer 20 on the inner wall of the shielding hole 12 may be 20 to 26 μm.

Like this, metal shielding layer 20 has sufficient shielding effect on the one hand, is difficult to drop from the inner wall of shielding hole 12, and on the other hand, metal shielding layer 20's thickness is thinner relatively, when crossing reflow soldering piece, can not cause the influence to the thermal energy of base plate 10, perhaps the influence that causes can be ignored, can avoid the warpage phenomenon, guarantees to paste effective going on of piece.

It should be noted that the numerical values and numerical ranges referred to in this application are approximate values, and there may be some error due to the manufacturing process, and the error may be considered to be negligible by those skilled in the art.

Optionally, referring to fig. 1, the shielding holes 12 are circular holes, the shielding holes 12 are arranged in an annular array at the periphery of the shielding cavity 11, the aperture of each shielding hole 12 (e.g., the distance indicated by R1 in fig. 1) is 0.25 to 0.5mm, and the hole distance between adjacent shielding holes 12 (e.g., the distance indicated by D1 in fig. 1) is 0.5 to 2.0 mm.

Those skilled in the art can understand that, the shielding holes 12 are formed on the periphery of the shielding cavity 11, and a drill or other grooving and hole-digging tools are required to dig holes in the substrate 10, and the number of the dug holes is positively correlated with the production efficiency; therefore, the embodiment of the application arranges a plurality of round holes in an array manner, so that gaps are formed among the shielding holes 12, the number of the dug holes can be reduced, and the processing cost is reduced.

Obviously, the smaller the diameter of the shielding hole 12, the higher the accuracy of the boring tool is required, and in order to reduce the cost, the diameter of the shielding hole 12 is set to be greater than or equal to 0.25mm in the embodiment of the present application.

It can be understood that, under the condition that the aperture of the shielding hole 12 is too large, on one hand, the opening of the shielding cavity 11 is affected, and on the other hand, the metal shielding layer 20 on the inner wall of the shielding hole 12 is easy to fall off, and the metal shielding layer 20 is not easy to be protected; therefore, the aperture of the shielding hole 12 is set between 0.25mm and 0.5mm in the embodiment of the application, so that the cost can be saved, the processing efficiency can be improved, and the metal shielding layer 20 in the shielding hole 12 can be effectively protected.

It should be noted that, the metal shielding layers 20 are disposed in the shielding holes 12, and those skilled in the art can understand that when the distance between adjacent shielding holes 12 is too large, the distance between the metal shielding layers 20 is large, which is easy to cause signal leakage, and the shielding effect is not good. And the gap between the adjacent shield holes 12 is too small, the number of openings needs to be increased. Therefore, in the embodiment of the present application, the distance between the adjacent shielding holes 12 is set to be 0.5 to 2.0 mm. Therefore, on one hand, the signal shielding effect can be guaranteed, on the other hand, the number of the holes of the shielding holes 12 can be reduced, the processing efficiency is improved, and the processing cost is saved.

Optionally, the minimum distance between the hole edge of the shielding hole 12 and the edge of the shielding cavity 11 is greater than or equal to 0.5 mm.

Like this, can avoid carrying out gong groove to shielding chamber 11, cause the influence to shielding hole 12, can effectively protect metallic shield 20 in shielding hole 12.

Optionally, referring to fig. 2, in the embodiment of the present application, the shielding substrate 1 further includes a filling member 30, and the filling member 30 is filled in the shielding hole 12.

Specifically, in the embodiment of the present application, the material of the filling member 30 may be the same as or similar to the material of the substrate 10; for example, when epoxy resin is used for the substrate 10, epoxy resin may be used for the filler 30, and the shielding holes 12 may be filled with epoxy resin ink by a vacuum plugging machine.

Alternatively, referring to fig. 3, fig. 3 is a cross-sectional view of a second example of the shielding substrate provided in the embodiment of the present application. In the embodiment of the present application, the shielding hole 12 has a metal ring 13 at the hole edge, the metal ring 13 is located on two opposite surfaces of the substrate 10, and the width of the metal ring 13 is 0.1-0.2 mm.

Specifically, in the embodiment of the present invention, the substrate 10 may be an epoxy resin substrate with copper coated on both sides, so that the metal shielding layer 20 can be deposited and electroplated in the shielding hole 12 conveniently. The metal ring 13 may be formed by removing the double-sided copper on the substrate 10 by chemical etching after the substrate 10 is manufactured, and leaving the copper layer at the hole edge of the shielding hole 12.

In this way, the metal ring 13 can also protect the metal shield layer 20, and can also enhance the shielding effect.

In one possible example, referring to fig. 4, fig. 4 is a front view of a third example of the shielding substrate provided in the embodiment of the present application. In the embodiment of the present application, the shielding hole 12 is a strip-shaped hole, and the strip-shaped hole is discontinuously surrounded on the periphery of the shielding cavity 11.

It is understood that the metal shielding layer 20 may also be formed on the inner wall of the shielding hole 12 in the same or similar manner as the previous embodiment, and further description of this embodiment is omitted. Thus, the signal shielding effect can be improved.

In other possible examples, referring to fig. 5, fig. 5 is a cross-sectional view of a fourth example of the shielding substrate provided by the embodiment of the present application. The metal shield layer 20 may also be formed on the peripheral wall of the shield cavity 11.

Thus, the processing cost of the shield substrate 1 can be saved, and the production efficiency can be improved.

In a specific arrangement, the metal shielding layer 20 may be formed on the peripheral wall of the shielding cavity 11 by the aforementioned chemical deposition and electroplating.

Referring to fig. 6 and 7, a Circuit Board according to an embodiment of the second aspect of the present application may be specifically a Printed Circuit Board (PCB). The shielding substrate comprises a first sub-board 2, a second sub-board 3 and the shielding substrate 1 provided by any optional embodiment of the first aspect of the present application;

the first sub-board 2 is provided with a plurality of first signal units 201, the second sub-board 3 is provided with a plurality of second signal units 301, the shielding substrate 1 is located between the first sub-board 2 and the second sub-board 3, and the plurality of first signal units 201 and the plurality of second signal units 301 correspond to the plurality of shielding cavities 11 on the shielding substrate 1 one to one.

Specifically, in the embodiment of the present application, the first sub-board 2 may be one of a single-sided board, a double-sided board, or a multi-layered board, and the second sub-board 3 may be another one of the single-sided board, the double-sided board, or the multi-layered board. It will be understood by those skilled in the art that the first sub-board 2 and the second sub-board 3 are actually PCBs. That is, the circuit board provided by the embodiment of the present application is formed by laminating two PCBs and a shielding substrate 1.

In this way, the first sub-board 2 and the second sub-board 3 are press-fitted on the shield substrate 1 made of a non-metallic material. The thermal expansion coefficient of the substrate 10 made of the non-metal material is close to or similar to that of the first sub-board 2 and the second sub-board 3 (the first sub-board 2 and the second sub-board 3 are both PCB boards made of epoxy resin), so that when reflow soldering is carried out on a piece, the situation of warping cannot occur, and smooth proceeding of the piece can be guaranteed.

It should be noted that, in the embodiment of the present application, the first signal unit 201 and the second signal unit 301 are generally referred to as signal pads in the art.

Optionally, in the embodiment of the present application, a distance between an edge of the first signal unit 201 and an edge of the second signal unit 301 and an inner wall of the shielding cavity 11 is greater than or equal to 1.0 mm.

That is, in the embodiment of the present application, when the shielding cavity 11 is opened, the opening needs to be performed according to the sizes of the first signal unit 201 and the second signal unit 301, for example, the first signal unit 201 and the second signal unit 301 are generally square blocks of 10 × 10mm, and therefore, the shielding cavity 11 may be set to be the square block of 11 × 11 mm. Like this, after first daughter board 2 and the pressfitting of second daughter board 3 are on shielding base plate 1, shielding cavity 11 can not cause the influence to the signal pad, can provide sufficient space for the signal pad to guarantee that the signal is smooth to propagate in shielding cavity 11.

Optionally, in this embodiment of the application, the circuit board further includes: and a first adhesive layer 4 between the first sub-board 2 and the shield substrate 1 for connecting the first sub-board 2 and the shield substrate 1.

Specifically, in the embodiment of the present application, the first adhesive layer 4 may be made of an epoxy resin material, and the first adhesive layer 4 made of epoxy resin has a better heat resistance, and the adhesive type at normal temperature is weaker and is fully cured under a high-temperature and high-pressure condition, so that when the first daughter board 2 is adhered to the shielding substrate 1, the position of the first daughter board 2 may be adjusted and aligned, so that the adhering precision between the first daughter board 2 and the shielding substrate 1 is higher.

And a second adhesive layer 5 between the second sub-board 3 and the shield substrate 1 for connecting the second sub-board 3 and the shield substrate 1.

Specifically, in the embodiment of the present application, the same epoxy resin material as that of the first adhesive layer 4 may be used for the second adhesive layer 5.

In specific arrangement, referring to fig. 8 and 9, in the embodiment of the present application, the first adhesive layer 4 and the second adhesive layer 5 are both provided with an opening 401, the opening 401 is arranged corresponding to the shielding cavity 11, and the size of the opening 401 is greater than or equal to the size of the opening of the shielding cavity 11.

In this way, the first adhesive layer 4 and the second adhesive layer 5 can be easily attached to the shield substrate 1, and the influence of the first adhesive layer 4 and the second adhesive layer 5 on the signal pad can be avoided.

In particular, the openings 401 of the first adhesive layer 4 and the second adhesive layer 5 may be set to have the same size as the opening of the shielding cavity 11, so that the bonding strength between the shielding substrate 1 and the first daughter board 2 and the second daughter board 3 can be ensured, and the bonding stability can be ensured.

In one particular example, the spacing between adjacent apertures 401 is greater than or equal to 1 mm.

Specifically, as shown in fig. 8, a certain amount of adhesive material is retained between adjacent openings 401 of the first adhesive layer 4 or the second adhesive layer 5, and the adhesive material is adhered between adjacent shielding cavities 11 of the shielding substrate 1, and in order to ensure that the first adhesive layer 4 or the second adhesive layer 5 has sufficient adhesive strength, in the embodiment of the present invention, the width of the adhesive material is set to be at least not less than 1 mm. Therefore, the first adhesive layer 4 and the second adhesive layer 5 can have sufficient adhesive strength, and the adhesive stability between the first sub-board 2 and the shielding substrate 1 and between the second sub-board 3 and the shielding substrate 1 can be ensured.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (10)

1. A shield substrate, comprising:

the shielding structure comprises a substrate, wherein a plurality of shielding cavities are formed in the substrate, penetrate through two opposite surfaces of the substrate and are made of non-metal materials;

and the metal shielding layer is arranged around the periphery of each shielding cavity.

2. The shield substrate according to claim 1, wherein a plurality of shield holes are formed around a periphery of the shield cavity, the plurality of shield holes extend through opposite surfaces of the substrate, and the metal shield layer is disposed in the shield holes.

3. The shield substrate according to claim 2, wherein the metal shield layer is disposed on an inner wall of the shield hole and has a thickness of 20 to 26 μm.

4. The shielding substrate according to claim 3, further comprising a filling member, wherein the filling member is filled in the shielding hole.

5. The shielding substrate according to any one of claims 2 to 4, wherein the shielding holes are circular holes, the shielding holes are arranged in an annular array on the periphery of the shielding cavity, the diameter of each shielding hole is 0.25 to 0.5mm, and the distance between adjacent shielding holes is 0.5 to 2.0 mm.

6. The shielding substrate according to any one of claims 2 to 4, wherein a minimum distance between an aperture edge of the shielding aperture and an edge of the shielding cavity is greater than or equal to 0.5 mm.

7. The shielding substrate according to any one of claims 2 to 4, wherein the shielding holes are strip-shaped holes, and the strip-shaped holes are discontinuously arranged around the periphery of the shielding cavity.

8. The shielding substrate according to claim 1, wherein the metal shielding layer is disposed on an inner wall of a circumference of the shielding cavity.

9. A circuit board comprising a first sub-board, a second sub-board, and the shield substrate of any one of claims 1-8;

the shielding substrate is arranged between the first daughter board and the second daughter board, and the shielding substrate is provided with a plurality of first signal units and a plurality of second signal units, wherein the first signal units and the second signal units are in one-to-one correspondence with a plurality of shielding cavities on the shielding substrate.

10. The circuit board of claim 9, further comprising:

the first bonding layer is positioned between the first sub-board and the shielding substrate and is used for connecting the first sub-board and the shielding substrate;

and the second bonding layer is positioned between the second sub-board and the shielding substrate and is used for connecting the second sub-board and the shielding substrate.

Images