CN112203407A

CN112203407A - Printed circuit board

Info

Publication number: CN112203407A
Application number: CN202010081335.6A
Authority: CN
Inventors: 闵太泓; 金柱澔
Original assignee: Samsung Electro Mechanics Co Ltd
Current assignee: Samsung Electro Mechanics Co Ltd
Priority date: 2019-07-08
Filing date: 2020-02-06
Publication date: 2021-01-08
Also published as: CN112203408A

Abstract

A printed circuit board is disclosed. The printed circuit board includes: a first substrate section; and a second substrate section connected to the first substrate section and having a flexible insulating layer that can be bent, and the second substrate section includes a frame member inserted in the flexible insulating layer.

Description

Printed circuit board

This application claims the benefit of priority of korean patent application No. 10-2019-0082246, filed in the korean intellectual property office at 7/8.2019 and korean patent application No. 10-2019-0085883, filed in the korean intellectual property office at 7/16.2019, the disclosures of which are incorporated herein by reference in their entireties.

Technical Field

The present disclosure relates to a printed circuit board.

Background

Recently, with the development of ultra high definition displays and antenna modules for high frequency transmission, the demand for printed circuit boards having a rigid-flexible structure has been increasing.

In addition, in order to apply a printed circuit board having a rigid-flexible structure to a device having high performance, a high circuit density is required in a limited space, and thus, demand for a technique for mounting an electronic device in a flexible substrate part or implementing a microcircuit in the flexible substrate part is increasing.

Disclosure of Invention

An aspect of the present disclosure is to provide a printed circuit board including: a first substrate section; and a second substrate section connected to the first substrate section and having a flexible insulating layer that can be bent, the second substrate section including a frame member inserted in the flexible insulating layer.

Another aspect of the present disclosure is to provide a printed circuit board including: a first substrate section; and a second substrate section including a flexible insulating layer that can be bent surrounding a frame member and connected to the first substrate section.

Other features and aspects will be apparent from the following detailed description, the accompanying drawings, and the claims.

Drawings

The above and other aspects, features and advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

fig. 1 is a diagram illustrating a printed circuit board according to an embodiment of the present disclosure;

fig. 2 and 3 are diagrams illustrating a second substrate section in a printed circuit board according to an embodiment of the present disclosure;

fig. 4 is a diagram illustrating another example of a frame member of a printed circuit board according to an embodiment of the present disclosure;

fig. 5 and 6 are diagrams illustrating a second substrate section in a printed circuit board according to another embodiment of the present disclosure; and is

Fig. 7 to 11 are diagrams illustrating a method of manufacturing a second substrate section in a printed circuit board according to an embodiment of the present disclosure.

Detailed Description

Hereinafter, embodiments of the present disclosure will be described as follows with reference to the accompanying drawings.

This disclosure may, however, be embodied in many different forms and should not be construed as limited to the specific embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

Throughout the specification, it will be understood that when an element such as a layer, region or wafer (substrate) is referred to as being "on," "connected to" or "bonded to" another element, it can be directly on, "connected to" or "bonded to" the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly on," "directly connected to" or "directly coupled to" another element, there may be no intervening elements present. Like reference numerals refer to like elements throughout. As used herein, the term "and/or" includes any and all combinations of any one or more of the associated listed items.

It will be apparent that, although the terms "first," "second," "third," etc. may be used herein to describe various members, components, regions, layers and/or sections, these members, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

Spatially relative terms, such as "above," "upper," "lower," and "below," may be used herein for ease of description to describe one element's relationship to another element as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other elements or features would then be oriented "below" or "beneath" the other elements or features. Thus, the term "above" may include both an above orientation and a below orientation, depending on the particular orientation of the figure. The device may also be otherwise positioned (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

The terminology used herein describes particular embodiments only, and the disclosure is not so limited. As used herein, the singular is intended to include the plural unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Hereinafter, embodiments of the present disclosure will be described with reference to schematic drawings showing embodiments of the present disclosure. In the drawings, modifications to the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, may be considered. Thus, embodiments of the present disclosure should not be construed as limited to the particular shapes of regions illustrated herein but are to include, for example, variations in shapes that result from manufacturing. The following embodiments may also be constituted by one of them or a combination of them.

The present disclosure described below may have various configurations, and only required configurations are set forth herein, but is not limited thereto.

Fig. 1 is a diagram illustrating a printed circuit board according to an embodiment of the present disclosure. Fig. 2 and 3 are diagrams illustrating a second substrate section in a printed circuit board according to an embodiment of the present disclosure.

Referring to fig. 1 to 3, a printed circuit board according to an embodiment of the present disclosure includes a first substrate part 10 and a second substrate part 20.

The first substrate portion 10 has a portion to which the second substrate portion 20 is connected. The first substrate portion 10 according to the embodiment may be a rigid substrate that cannot be bent. That is, the first substrate portion may be formed using a material having a higher rigidity than that of the second substrate portion 20 having the

flexible insulating layers

22 and 24.

Further, a portion of the first substrate section 10 connected to the second substrate section 20 may be provided as a rigid substrate, and another portion of the first substrate section 10 may be provided as a flexible substrate.

The second substrate section 20 is connected to the first substrate section 10, and has bendable

flexible insulating layers

22 and 24. The printed circuit board according to the embodiment may be provided as a printed circuit board (rigid-flexible PCB) having a rigid-flexible structure in which the first substrate section 10 is a rigid substrate and the second substrate section 20 is a flexible substrate.

For example, a flexible insulating layer (such as a polyimide film) is stacked to form a bendable flexible substrate. Then, a circuit pattern and a hard insulating layer (an insulating layer relatively harder than a flexible insulating layer) such as epoxy resin are additionally formed on the flexible substrate. Therefore, a hard substrate formed using a material harder than that of the flexible substrate can be provided. Accordingly, a printed circuit board having a rigid-flexible structure in which only a portion where a flexible substrate is held is provided as the second substrate section 20 (flexible substrate which can be bent), and the remaining portion is provided as the first substrate section 10 (hard substrate) can be provided. Here, "flexible" and "hard" refer to differences in the degree of bending relative to each other. Here, a material having sufficient strength to be able to bend according to the user's intention is referred to as a flexible material, and a material that cannot bend is referred to as a hard material.

In detail, the second substrate part 20 according to the embodiment may include a frame member 30 inserted into the

flexible insulating layers

22 and 24. The frame member 30 may be inserted into portions of the

flexible insulating layers

22 and 24 that do not need to be bent, thereby increasing strength and suppressing deformation (expansion or contraction) caused by heat. Accordingly, due to the increased dimensional stability of the

flexible insulating layers

22 and 24 into which the frame member 30 is inserted, a fine circuit pattern may be formed on the second substrate part 20 or an electronic component may be mounted on the second substrate part 20. The frame member 30 may include a metal, ceramic, or alloy having a low thermal expansion coefficient, such as an invar (invar) alloy or a covar (covar) alloy, to increase the strength of the second substrate portion 20 and prevent thermal deformation.

Referring to fig. 2, the second substrate part 20 according to the embodiment may include: a first region 20a provided adjacent to the first substrate section 10 and connected to the first substrate section 10, and the first region 20a may be bent; and a second region 20b spaced apart from the first substrate portion 10 and into which the frame member 30 is inserted. That is, the second substrate portion 20 formed using the

flexible insulating layers

22 and 24 may be divided into a first region 20a into which the frame member 30 is not inserted and a second region 20b (including an inner region of the frame member 30) into which the frame member 30 is inserted. In this case, the first region 20a (bendable portion) is a portion connected to the first substrate section 10. Therefore, when the bending of the second substrate section 20 with respect to the first substrate section 10 is required, the first region 20a of the second substrate section 20 may be bent or folded.

The frame member 30 according to the embodiment may have a shape in which the bar portions 32 in a straight form or a curved form are connected to each other. For example, the frame member is formed to have a shape similar to the boundary of the second region 20b and thus may be inserted therein along the boundary of the second region 20 b. In this case, the inside of the frame member 30 is penetrated, and thus an empty space (or accommodation space) 34 or a recess (not shown) may be provided. The via hole of the second substrate part 20 may be disposed in the empty space 34 of the frame member 30.

Further, an empty space 34 is formed in the inner region of the frame member 30, and the flexible insulating

layers

22 and 24 disposed in the empty space 34 of the frame member 30 are also locked by the frame member 30. Therefore, expansion and contraction due to heat are suppressed, and thus dimensional stability can be ensured.

Referring to fig. 3, a circuit pattern 26 may be formed on one surface of the flexible insulating

layers

22 and 24. In this case, the circuit pattern 26 includes the pad 26b on which the first electronic component 40 is mounted (specifically, the pad 42 of the first electronic component 40 is mounted on the pad 26b of the circuit pattern 26), and the pad 26b may be formed on the second region 20 b. The pad 26b on which the first electronic component 40 is mounted may require high dimensional stability for reliable connection. Therefore, the pad 26b is preferably formed in the second region 20b (including the inner region of the frame member 30) into which the frame member 30 is inserted. The pads 26b may have low thermal deformation and high strength compared to the portions 26a of the circuit pattern 26 formed in the region outside the frame member 30.

Further, in the embodiment, it is assumed that the frame member 30 having the closed curve structure has a structure in which the inner space is closed by the side surface, but the embodiment is not limited thereto. Alternatively, the frame member may have a structure in which a side surface portion of the frame member 30 is opened.

In addition, a primer or metal particles may be coated on the surface of the frame member 30 inserted into the flexible insulation layers 22 and 24. The primer or the metal particles such as copper may increase the bonding force between the flexible insulating

layers

22 and 24 and the frame member 30.

In addition, the flexible insulation layers 22 and 24 according to the embodiment may have a composite structure formed using the first insulation material 22 and the second insulation material 24.

Referring to fig. 3, a through-hole 23 into which the frame member 30 is inserted may be formed in the first insulating material 22. The second insulating material 24 may have a structure in which the first insulating material 22 and the frame member 30 are embedded. The first insulating material 22 forms a main portion of the flexible insulating

layers

22 and 24, and the second insulating material 24 may bond the frame member 30 disposed in the through-hole 23 of the first insulating material 22 to the first insulating material 22. In this case, in order to easily perform filling between the first insulating material 22 and the frame member 30, the second insulating material 24 may be formed using a material having higher fluidity than that of the first insulating material 22.

In this case, the first insulating material 22 may include polyimide or Liquid Crystal Polymer (LCP). In detail, Liquid Crystal Polymers (LCPs) have a coefficient of thermal expansion similar to that of copper, and thus undergo less deformation during processing. Furthermore, the dimensional stability of LCP is higher than that of other materials. In addition, LCP has a low dielectric constant and low dielectric loss, and thus is advantageous for high-speed signal transmission.

Fig. 4 is a diagram illustrating another example of a frame member of a printed circuit board according to an embodiment of the present disclosure.

Referring to fig. 4, the frame member 35 may have a plurality of layers. For example, a copper layer 38 may be stacked on each of two sides of an alloy layer 36 having a low coefficient of thermal expansion (such as invar or kovar) to form the frame member 35.

Fig. 5 and 6 are diagrams illustrating a second substrate section in a printed circuit board according to another embodiment of the present disclosure.

Referring to fig. 5 and 6, a penetrated accommodation space 34 is formed in the frame member 30 according to the embodiment, and a second electronic element 45 is disposed in the accommodation space 34 to be embedded in the flexible insulation layers 22 and 24.

In this case, the frame member 30 may include an electromagnetic interference (EMI) shielding material. For example, the frame member 30 may be at least one of a non-metallic magnetic material and a metal.

In addition, the circuit pattern 26 formed on one side of the flexible insulating

layers

22 and 24 may be electrically connected to the second electronic element 45. For example, the portion 26c of the circuit pattern 26 may be connected to the electrode 46 of the second electronic element 45 through a via hole.

In addition, the receiving space 34 of the frame member 30 is covered with the metal layer formed on the flexible insulating

layers

22 and 24, and thus the EMI shielding effect can be improved.

Referring to fig. 7, a first insulating material 22 having a via 23 may be stacked on the carrier 5. In this case, the through-hole 23 is formed in the first insulating material 22, and then the first insulating material 22 may be attached to the carrier 5.

Referring to fig. 8, the frame member 30 is provided to be inserted into the through-hole 23 of the first insulating material 22. In this case, the frame member 30 may be attached to the carrier 5 or the frame member 30 may be supported by the carrier 5.

Referring to fig. 9, the through-hole 23 of the first insulating material 22 is filled with the second insulating material 24, and thus the frame member 30 and the first insulating material 22 may be bonded to each other. In this case, in order to easily perform filling between the first insulating material 22 and the frame member 30, the second insulating material 24 may be formed using a material having higher fluidity than that of the first insulating material 22. Further, the second insulating material 24 is stacked on each of both sides of the first insulating material 22, and thus the second insulating material 24 may embed the first insulating material 22 and the frame member 30. Furthermore, a second insulating material 24 is stacked on one side of the first insulating material 22, from which (i.e. the now formed structure) the carrier 5 can then be removed.

Referring to fig. 10 and 11, a metal layer 25 is formed on one or both sides of the second insulating material 24, and the metal layer 25 is patterned to form a circuit pattern 26.

While exemplary embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the scope of the invention as defined by the appended claims.

Claims

1. A printed circuit board comprising:

a first substrate section; and

a second substrate section connected to the first substrate section and having a flexible insulating layer capable of being bent,

wherein the second substrate portion includes a frame member inserted in the flexible insulating layer.

2. The printed circuit board of claim 1, wherein the second substrate portion comprises:

a first region adjacent to and connected to the first substrate portion, and the first region being bendable; and

a second region spaced apart from the first substrate portion, and into which the frame member is inserted.

3. The printed circuit board according to claim 2, wherein one side of the flexible insulating layer is provided to be formed with a land on which the first electronic component is mounted, and

the pad is formed on the second region.

4. The printed circuit board according to claim 1, wherein the frame member is provided with a receiving space penetrated, and

the printed circuit board further includes a second electronic component disposed in the accommodating space and embedded in the flexible insulating layer.

5. The printed circuit board of claim 4, wherein the frame member comprises an electromagnetic interference shielding material.

6. The printed circuit board of claim 5, wherein the frame member comprises at least one of a non-metallic magnetic material and a metal.

7. The printed circuit board of claim 1, wherein the flexible insulating layer comprises:

a first insulating material having a through hole into which the frame member is inserted; and

a second insulating material, the first insulating material and the frame member being embedded in the second insulating material.

8. The printed circuit board of claim 7, wherein the first insulating material comprises a liquid crystal polymer.

9. The printed circuit board of claim 7, wherein the second insulating material has a higher fluidity than that of the first insulating material.

10. The printed circuit board of claim 1, wherein a surface of the frame member is provided with a primer or metal particles, the primer or the metal particles being coated to the surface of the frame member.

11. The printed circuit board of claim 1, wherein the frame member has a plurality of layers.

12. A printed circuit board comprising:

a first substrate section; and

a second substrate section including a flexible insulating layer that can be bent surrounding a frame member, and connected to the first substrate section.

13. The printed circuit board of claim 12, wherein the second substrate portion further comprises a first region contacting the first substrate portion and a second region spaced apart from the first substrate portion, wherein the first region is bendable and the second region surrounds the frame member.

14. The printed circuit board of claim 12, wherein the frame member comprises a metal, a non-metallic magnetic material, or a combination of metal and non-metallic magnetic materials.

15. The printed circuit board of claim 12, wherein the flexible insulating layer comprises: a first insulating material surrounding the frame member; and a second insulating material embedding the first insulating material and the frame member.

16. The printed circuit board of claim 12, wherein the frame member includes a recess configured to receive an electronic component disposed therein and embedded in the flexible insulating layer.