Cover opening structure of rigid-flex board
By setting a through groove on the curing sheet and filling it with resin glue, the problems of difficulty in opening the cover and abnormal quality of the soft and hard combination circuit board are solved, more efficient laser depth control and lower glass fiber residue are achieved, and the opening efficiency and quality are improved.
Patent Information
- Application Number
- CN202422326895.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-23
- Publication Date
- 2025-10-28
- Estimated Expiration
- 2034-09-23
AI Technical Summary
The existing method of opening the cover of rigid-flex circuit boards makes it difficult to control the depth of the workpiece due to the influence of the woven glass fiber cloth in the semi-solid and cured sheets. This can easily lead to quality problems such as inadequate depth control, residual glass fiber, low opening efficiency, and torn boards.
A through groove is set on the solidified sheet, and resin glue is filled in the semi-solid sheet. The through groove is located at the connection position of the soft board area and the hard board area. The resin glue is removed by laser to expose the circuit board, avoiding the difficulty of laser processing of woven glass fiber cloth. A flexible circuit board and a resist film are used to protect the circuit board.
It reduces the difficulty of laser depth control, improves the efficiency of opening the lid, reduces the problems of glass fiber residue and quality abnormalities, and improves the efficiency and quality of opening the lid.
Smart Images
Figure CN223488461U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of rigid-flex PCB technology, and in particular to a rigid-flex PCB opening structure. Background Technology
[0002] Existing rigid-flex circuit boards are generally multi-layered structures, including a flexible board and insulating plates set at the top and bottom of the flexible board. The circuit board is set at a specific position on the surface of the flexible board. In use, a laser is used to cut off part of the insulating plate to expose the circuit board for power connection.
[0003] See Figure 1 As shown, Figure 1 This describes the structure of a rigid-flex PCB in existing technology. In the diagram, A represents the flexible PCB area, and B represents the rigid PCB area. In existing rigid-flex PCB structures, the insulating board is a semi-solid sheet 2' + a cured sheet 3' (single-sided / double-sided copper-clad laminate), or a semi-solid sheet 2' + a copper foil layer. The cured sheet can also be called a resin rigid PCB layer. See also... Figure 2 As shown, the semi-solid and cured sheets in the prior art are made of the same material, the only difference being that the semi-solid sheet is in an uncured state, while the cured sheet is a cured hard layer. The structures of the semi-solid and cured sheets are as follows: Figure 2 As shown, Figure 2 This is a schematic diagram of the structure of a semi-solid sheet and a cured sheet in the prior art; it includes a fiberglass cloth 100 and a resin adhesive 200, with the resin adhesive 200 wrapped around the fiberglass cloth 100.
[0004] The applicant has discovered that the prior art has at least the following technical problems: The conventional opening method in the prior art is laser depth control opening. Due to the influence of the woven fiberglass cloth in the semi-solid and solidified sheets, the depth control operation is very difficult, often resulting in inadequate depth control leading to fiberglass residue, low opening efficiency, and damaged boards, among other quality abnormalities. Utility Model Content
[0005] The purpose of this utility model is to provide a flexible and rigid bonding plate opening structure to solve the technical problems of difficult opening of flexible and rigid bonding plates and easy quality abnormalities in the prior art; the various technical effects of the preferred technical solution among the many technical solutions provided by this utility model are described in detail below.
[0006] To achieve the above objectives, the present invention provides the following technical solutions:
[0007] The rigid-flex PCB opening structure provided by this utility model includes a circuit board and an insulating plate covering opposite sides of the circuit board, wherein:
[0008] The insulating board includes a semi-solid sheet and a cured sheet. The cured sheet is fixed to the surface of the semi-solid sheet. A through groove is provided on the cured sheet. The through groove is located in the flexible board area and extends through the opposite sides of the cured sheet. The resin adhesive in the semi-solid sheet fills the through groove.
[0009] Preferably, the through slot is located at the junction of the flexible board area and the rigid board area.
[0010] Preferably, the curing sheet is fixed to one side surface or opposite two sides of the semi-curing sheet.
[0011] Preferably, the cured sheet is a fiberglass cloth resin rigid plate layer.
[0012] Preferably, the semi-solid sheet is a fiberglass cloth semi-solid sheet.
[0013] Preferably, the side of the cured sheet opposite to the semi-cured sheet or the opposite sides are covered with a copper plate, or the cured sheet is a fiberglass cloth resin rigid plate layer without copper coating.
[0014] Preferably, the width of the through groove is in the range of 0.1mm-0.6mm.
[0015] Preferably, the circuit board is a flexible circuit board, and one side or the top and bottom sides of the flexible circuit board are covered with a resist film. The resist film is located in the flexible board area and is located between the flexible circuit board and the insulating board.
[0016] Preferably, the flexible circuit board includes a polyimide film, and copper layers are fixed on both the upper and lower surfaces of the polyimide film, and polyimide film cover films are fixed on both the upper and lower outer surfaces of the copper layers.
[0017] Preferably, the outer surface of the rigid plate area of the rigid-flex plate is provided with an ink layer for solder resist.
[0018] The flexible-rigid composite board opening structure provided by this utility model has the following advantages compared with the prior art: The insulating board includes a semi-solid sheet and a cured sheet. A through groove is opened on the cured sheet. Since the semi-solid sheet is not completely cured, the resin adhesive in the semi-solid sheet can fill the through groove. Since the difficulty of laser depth control / blind gong depth control processing lies in the woven fiberglass cloth, this setting means that the through groove does not contain woven fiberglass cloth, but only resin adhesive. The resin adhesive has little impact on laser depth control. The through groove serves as the laser depth control / blind gong depth control area, which facilitates laser depth control opening, reduces the difficulty of laser depth control, improves work efficiency, and reduces the occurrence of quality abnormalities such as fiberglass residue, low opening efficiency, and board tearing. Attached Figure Description
[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0020] Figure 1 This is the structure of a rigid-flex PCB in the prior art; in the diagram, 2' is the semi-solid sheet; 3' is the hardened sheet;
[0021] Figure 2 yes Figure 2 This is a schematic diagram of the structure of semi-solid sheets and cured sheets in the prior art; in the diagram, 100 represents fiberglass cloth; 200 represents resin adhesive;
[0022] Figure 3 This utility model relates to a flexible and rigid combined plate opening structure;
[0023] Figure 4 This is an exploded view of the flexible circuit board.
[0024] In the diagram: 1. Circuit board; 11. Polyimide film; 12. Copper layer; 13. Polyimide film; 2. Semi-solid sheet; 3. Cured sheet; 31. Through groove; 4. Copper plate; 5. Ink layer; 6. Resistant film; 200. Resin adhesive. Detailed Implementation
[0025] To make the purpose, technical solution, and advantages of the present invention more clear, the technical solution of the present invention will be described in detail below. Obviously, the embodiments described are only some of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.
[0026] In the description of this utility model, it should be understood that the terms "center," "length," "width," "height," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and "side," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.
[0027] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0028] See Figure 1 As shown, Figure 1 This describes the structure of a rigid-flex PCB in existing technology. In the diagram, A represents the flexible PCB area, and B represents the rigid PCB area. In existing rigid-flex PCB structures, the insulating board is a semi-solid sheet 2' + a cured sheet 3' (single-sided / double-sided copper-clad laminate), or a semi-solid sheet 2' + a copper foil layer. The cured sheet can also be called a resin rigid PCB layer. See also... Figure 2 As shown, the semi-solid and cured sheets in the prior art are made of the same material, the only difference being that the semi-solid sheet is in an uncured state, while the cured sheet is a cured hard layer. The structures of the semi-solid and cured sheets are as follows: Figure 2 As shown, Figure 2 This is a schematic diagram of the structure of a semi-solid sheet and a cured sheet in the prior art; it includes fiberglass cloth 100 and resin adhesive 200, with the resin adhesive 200 wrapped around the fiberglass cloth 100. The conventional opening method in the prior art is laser-controlled depth opening. Due to the influence of the woven fiberglass cloth in the semi-solid sheet and cured sheet, the depth control operation is very difficult, often resulting in incomplete depth control, leading to fiberglass residue, low opening efficiency, and damaged boards, among other quality abnormalities.
[0029] To address the aforementioned issues, this utility model provides a flexible-rigid composite board opening structure, which reduces the difficulty of laser depth control, improves work efficiency, and reduces quality defects such as fiberglass residue, low opening efficiency, and board tearing.
[0030] The following combination Figure 3 and Figure 4 The technical solution provided by this utility model will be described in more detail.
[0031] See Figure 3 As shown in the figure, A represents the flexible board area and B represents the rigid board area. The flexible-rigid board opening structure provided by this utility model includes a circuit board 1 and an insulating board covering opposite sides of the circuit board 1. The insulating board includes a semi-solid sheet 2 and a curing sheet 3. The curing sheet 3 is fixed to the surface of the semi-solid sheet 2. A through groove 31 is provided on the curing sheet 3. The through groove 31 is located in the flexible board area A and extends through opposite sides of the curing sheet 3. The resin glue 200 in the semi-solid sheet 2 fills the through groove 31.
[0032] Among them, see Figure 3As shown, the through groove 31 is located at the connection between the flexible board area A and the rigid board area B. That is, the position of the through groove 31 is the position for laser cutting. Since the resin glue 200 in the semi-solid sheet 2 is filled in the through groove 31, at the position of the through groove 31, only the resin glue 200 needs to be cut by laser, which makes it easier to control the depth and reduces the difficulty of laser depth control.
[0033] See Figure 2 As shown, the structure of the semi-solid sheet is as follows: Figure 2 As shown, since the semi-solid sheet 2 has not been fully cured, the resin adhesive 200 in the semi-solid sheet 2 can fill the through groove 31.
[0034] The flexible-rigid composite board opening structure provided by this utility model includes an insulating board comprising a semi-solid sheet 2 and a cured sheet 3. A through groove 31 is formed on the cured sheet 3. Since the semi-solid sheet 2 is not fully cured, the resin adhesive 200 in the semi-solid sheet 2 can fill the through groove 31. Since the difficulty of laser depth control / blind gong depth control processing lies in the woven fiberglass cloth, this setting means that the through groove 31 does not contain woven fiberglass cloth, but only resin adhesive 200. The resin adhesive 200 has little impact on laser depth control. The through groove 31 serves as the laser depth control / blind gong depth control area, which facilitates laser depth control opening, reduces the difficulty of laser depth control, improves work efficiency, and reduces the occurrence of quality abnormalities such as fiberglass residue, low opening efficiency, and board tearing.
[0035] As an optional implementation, the curing sheet 3 is fixed to one side surface or opposite sides of the semi-curing sheet 2.
[0036] Preferred, such as Figure 3 As shown, the curing sheet 3 is fixed to the opposite two side surfaces of the semi-cured sheet 2. With this arrangement, the resin adhesive 200 in the two semi-cured sheets 2 can be filled into the through groove 31 from both sides, preventing the through groove 31 from being incompletely filled with resin adhesive 200.
[0037] As an optional implementation, the cured sheet 3 in this embodiment is a fiberglass cloth resin rigid plate layer, with the structure as follows: Figure 2 As shown.
[0038] As an optional implementation, the semi-fixed sheet 2 in this embodiment is a fiberglass cloth semi-fixed sheet. The structure is as follows: Figure 2 As shown.
[0039] As an optional implementation, see Figure 3 As shown, the side of the cured sheet 3 opposite to the semi-cured sheet 2 or the opposite sides are covered with copper plates 4, or, not shown in the figure, the cured sheet 3 is a fiberglass cloth resin rigid plate layer without copper coating.
[0040] That is, the curing sheet 3 in this embodiment can be a double-sided copper-clad board, a single-sided copper-clad board, or a fiberglass cloth resin rigid board layer without copper cladding, which can be used to make 4-8 layer boards with flexible boards in the inner layer and 2-4 layer boards with flexible boards in the outer layer.
[0041] As an optional implementation, the width of the through groove 31 in this embodiment ranges from 0.1mm to 0.6mm, which facilitates the removal of the resin adhesive 200 at this location using a laser, exposing the circuit board 1 for electrical connection. The through groove 31 can be manufactured using laser cutting, mechanical milling, stamping die, etc.
[0042] As an optional implementation, see Figure 3 and Figure 4 As shown, the circuit board 1 is a flexible circuit board 1. One side or the top and bottom sides of the flexible circuit board 1 are covered with a resist film 6. The resist film 6 is located in the flexible board area and is located between the flexible circuit board 1 and the insulating board.
[0043] The aforementioned resist film 6 is used to prevent the resin adhesive 200 from flowing to the portion of the flexible circuit board 1 located in the flexible board area, thereby protecting the flexible circuit board 1.
[0044] As an optional implementation, see Figure 4 As shown, the flexible circuit board 1 includes a polyimide film 11, copper layers 12 are fixed on both the upper and lower surfaces of the polyimide film 11, and polyimide film cover films 13 are fixed on both the upper and lower outer surfaces of the copper layers 12. The circuit board 1 with this structure has a certain degree of flexibility.
[0045] As an optional implementation, see Figure 3 As shown, the outer surface of the rigid plate area of the rigid-flex board is provided with an ink layer 5 for solder resist, which can protect the rigid plate area structure of the rigid-flex board.
[0046] The process flow for the rigid-flex PCB cover structure in this embodiment is as follows:
[0047] Flexible Circuit Board Part 1: Material preparation, pretreatment, inner layer dry film, inner layer exposure, inner layer etching, AOI, browning, cover film lamination, cover film fast pressing, OPE punching. Adhesive Part (PP): PP material preparation, PP windowing, auxiliary material cleaning. Curing Sheet Part 3: Copper Clad Laminate Material Preparation, Inner Layer Circuit Etching, Double-sided or Single-sided Transition Through-groove 31. Bonding Part: Assembly and Lamination, Drilling and Copper Plating, Outer Layer Circuit, Solder Mask, Capping, Post-Processing of Rigid and Flexible Circuit Boards.
[0048] The specific features, structures, or characteristics described in this specification may be combined in any suitable manner in one or more embodiments or examples.
[0049] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0050] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.
Claims
1. A flexible-rigid composite plate opening structure, characterized in that, The rigid-flex board includes a circuit board and an insulating board covering opposite sides of the circuit board, wherein: The insulating board includes a semi-solid sheet and a cured sheet. The cured sheet is fixed to the surface of the semi-solid sheet. A through groove is provided on the cured sheet. The through groove is located in the flexible board area and extends through the opposite sides of the cured sheet. The resin adhesive in the semi-solid sheet fills the through groove. The through slot is located at the junction of the flexible board area and the rigid board area, and the location of the through slot is the location of laser cutting.
2. The flexible-rigid bonding plate opening structure according to claim 1, characterized in that, The curing sheet is fixed to one side surface or opposite two sides of the semi-curing sheet.
3. The flexible-rigid bonding plate opening structure according to claim 1, characterized in that, The cured sheet is a fiberglass cloth resin rigid plate layer.
4. The flexible-rigid bonding plate opening structure according to claim 1 or 3, characterized in that, The semi-solid sheet is a fiberglass cloth semi-solid sheet.
5. The flexible-rigid bonding plate opening structure according to claim 1, characterized in that, The cured sheet is covered with a copper plate on one side or opposite sides of the semi-cured sheet, or the cured sheet is a fiberglass cloth resin rigid plate layer without copper coating.
6. The flexible-rigid bonding plate opening structure according to claim 1, characterized in that, The width of the through groove ranges from 0.1mm to 0.6mm.
7. The flexible-rigid bonding plate opening structure according to claim 1, characterized in that, The circuit board is a flexible circuit board, and one side or the top and bottom sides of the flexible circuit board are covered with a resist film. The resist film is located in the flexible board area and is located between the flexible circuit board and the insulating board.
8. The flexible-rigid bonding plate opening structure according to claim 7, characterized in that, The flexible circuit board includes a polyimide film, and copper layers are fixed on both the upper and lower surfaces of the polyimide film. Polyimide film cover films are fixed on both the upper and lower outer surfaces of the copper layers.
9. The flexible-rigid bonding plate opening structure according to claim 1, characterized in that, The outer surface of the rigid plate area of the rigid plate is provided with an ink layer for solder resist.