CN214800040U - Metal-based rigid-flex board - Google Patents

Abstract

The utility model discloses a metal matrix soft or hard combination board, including metal matrix and all have first hard board, second hard board and the soft board of at least one deck circuit, the soft board includes that the soft or hard combination of both sides is regional with the soft board in the middle of, the regional both sides surface of soft board all is equipped with the protection film, be equipped with the recess on the metal matrix, the soft board is arranged in the recess, just the soft board with be equipped with the dielectric layer between the metal matrix, first hard board and second hard board are located through the dielectric layer bonding respectively the upper and lower surface of metal matrix, just first hard board, second hard board and metal matrix are gone up and are being corresponded the regional department of soft board all is equipped with the windowing to show out the protection film. The utility model discloses in through add the metal base that heat dispersion is good in the soft or hard combination board to improve the heat dispersion of board, solved the not good problem of FR4 panel heat dissipation in the current.

Description

Metal-based rigid-flex board

Technical Field

The utility model relates to a printed wiring board makes technical field, concretely relates to metal matrix soft or hard combined board and production method thereof.

Background

At present, with the development of the electronic industry, electronic products with high power and large current are more and more widely applied, and the requirements on circuit boards serving as electronic component carrier plates are also more and more high, wherein the important point is the requirement on the heat dissipation effect of the electronic components.

Industrial, medical, 3G cell phones, LCD televisions and other consumer electronics such as: the market demand for portable electronic products such as hard disk drives, floppy disk drives, mobile phones, notebook computers, cameras, camcorders, and PDAs for electronic computers is continuously expanding, and electronic devices are increasingly developing in the direction of being light, thin, short, small, and multifunctional. Particularly, the application of the flexible board for the High Density Interconnect (HDI) structure greatly drives the rapid development of the flexible printed circuit technology, and simultaneously, along with the development and improvement of the printed circuit technology, the development and research of the Rigid-Flex printed circuit board (logic-Flex PCB) are greatly applied, and the supply of the Rigid-Flex printed circuit board in the future in the world is expected to be greatly increased; meanwhile, the durability and flexibility of the rigid-flex printed circuit board make the rigid-flex printed circuit board more suitable for application in the fields of medical treatment and military affairs, and gradually increase the market share of rigid PCBs.

In the current industry, the rigid-flex board is generally formed by laminating an FR4 substrate (i.e. a rigid board) and a flexible board, and the FR4 dielectric layer portion of the FR4 substrate has poor heat dissipation performance, and cannot meet the current heat dissipation performance requirement.

SUMMERY OF THE UTILITY MODEL

The utility model discloses to the above-mentioned current technical defect, provide a metal base soft or hard combination board, add the good metal base of heat dispersion in soft or hard combination board to improve the heat dispersion of board, solved the not good problem of FR4 panel heat dissipation in the current.

In order to solve the technical problem, the utility model provides a metal matrix soft or hard combination board, including metal matrix and the first hard board, the second hard board and the soft board that all have at least one deck circuit, the soft board includes that the soft or hard combination of both sides is regional with the soft board in the middle of, the regional both sides surface of soft board all is equipped with the protection film, be equipped with the recess on the metal matrix, the soft board is arranged in the recess, just the soft board with be equipped with the dielectric layer between the metal matrix, first hard board and second hard board are located through the dielectric layer bonding respectively the upper and lower surface of metal matrix, just be corresponding on first hard board, the second hard board and the metal matrix the regional department of soft board all is equipped with the windowing to show out the protection film.

Further, the metal-based rigid-flex printed circuit board further comprises a first via hole for vertically conducting circuits on the first hard board, the soft board and the second hard board, a first copper plating layer for conducting is arranged on the hole wall of the first via hole, and a dielectric layer is arranged between the first copper plating layer and the metal base.

Further, the metal-based rigid-flex printed circuit board further comprises a second via hole for vertically conducting the circuit on the first hard board and the circuit on the second hard board, a second copper plating layer for conducting is arranged on the hole wall of the second via hole, and a dielectric layer is arranged between the second copper plating layer and the metal base.

Further, the metal-based rigid-flex printed circuit board further comprises a third via hole for vertically conducting the circuit on the first hard board and the circuit on the second hard board, a third copper plating layer for conducting is arranged on the hole wall of the third via hole, and the third copper plating layer is conducted with the metal base.

Further, the metal-based rigid-flex printed circuit board further comprises a fourth via hole for vertically conducting the circuits on the first hard board, the soft board and the second hard board, wherein a fourth copper plating layer for conducting is arranged on the hole wall of the fourth via hole, and the fourth copper plating layer is conducted with the metal base.

Furthermore, the first hard board, the second hard board and the soft board respectively comprise two layers of circuits.

Further, the size of the protective film is 0.5-1mm larger than that of the soft board area on one side.

Further, the metal matrix is copper-based or aluminum-based.

Further, the dielectric layer is a PP dielectric layer.

The utility model also provides a production method of metal matrix soft or hard combined board, including following step:

s1, cutting a metal base, a first PP sheet, a second PP sheet, a third PP sheet, a soft board, a first hard board and a second hard board, wherein the soft board comprises soft and hard combination areas at two sides and a soft board area in the middle, and the soft board, the first hard board and the second hard board are all double-sided copper-clad core boards;

s2, respectively manufacturing inner layer circuits on the soft board, the first hard board and the second hard board through a negative film process, and then pasting a protective film on the soft board area on the soft board;

s3, respectively drilling a first through hole and a second through hole on the metal matrix;

s4, depth control is carried out on the metal base to form a groove for accommodating the soft board, wherein the first through hole is located in the groove area, and the second through hole is located outside the groove area;

s5, windowing at positions, corresponding to the soft board area, on the first PP sheet and the second PP sheet;

s6, firstly, placing the soft board in a groove on the metal base, arranging a second PP sheet between the soft board and the bottom of the groove, then sequentially laminating a first PP sheet and a first hard board on the upper surface of the metal base from inside to outside, sequentially laminating a third PP sheet and a second hard board on the lower surface of the metal base from inside to outside, and then pressing to form a production board;

s7, coaxially drilling through holes with the aperture smaller than that of the through holes at positions, corresponding to the first through hole and the second through hole, on the production board, and then sequentially carrying out copper deposition and full-board electroplating to metalize the through holes to form a first through hole and a second through hole;

s8, manufacturing an outer layer circuit and a solder mask layer on the production board in sequence and carrying out surface treatment;

and S9, finally, removing the outer core material on the production board corresponding to the soft board area through depth control cutting and uncovering to expose the protective film on the inner soft board area, thereby obtaining the metal-based rigid-flex board.

Further, in step S2, the size of the protection film is 0.5 to 1mm larger than the size of the soft board area on one side.

Further, in step S4, the depth of the groove is 2/3-3/4 of the thickness of the metal matrix.

Further, in step S5, the size of the window is smaller than the size of the protective film by 0.5 to 1 mm.

Further, in step S7, through holes are drilled in the production board, the through holes vertically penetrating through the first hard board, the metal base and the second hard board, and the through holes vertically penetrating through the first hard board, the soft board, the metal base and the second hard board, and after metallization, a third via hole and a fourth via hole are respectively formed, the third via hole is used for conducting the first hard board, the metal base and the second hard board, and the fourth via hole is used for conducting the first hard board, the soft board, the metal base and the second hard board.

Compared with the prior art, the utility model discloses following beneficial effect has:

the flexible board is arranged in the groove of the metal base and then combined with the hard board to form the rigid-flexible board, so that the metal base with excellent heat dissipation performance is added in the middle of the rigid-flexible board, the metal base is utilized to dissipate heat to the board, the heat dissipation performance of the board is effectively improved, and the problem of poor heat dissipation of the conventional FR4 board is solved; in addition, the structure of conducting between the conducting hole and the metal base is utilized, and the heat conduction efficiency and effect are further improved.

The utility model discloses a method for manufacturing metal-based rigid-flex board, which provides a whole manufacturing process and can effectively and efficiently manufacture qualified metal-based rigid-flex board; in the method, the soft board is accommodated in the groove of the metal base by routing the groove, so that the problem of over-thickness of the board caused by the increased metal base is reduced as much as possible while the heat dissipation efficiency and effect are improved; in addition, a plurality of holes which are respectively communicated with the metal base or are not communicated with the metal base are formed on the plate, so that the heat conduction efficiency and the heat conduction effect of different circuits are realized, and the method can effectively ensure that the production quality of the plate is good.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

FIG. 1 is a schematic view of a metal-based rigid-flex circuit board according to example 1;

fig. 2 is a schematic view of a manufacturing process of the metal-based rigid-flex board in embodiment 2.

Detailed Description

In order to fully understand the technical contents of the present invention, the present invention will be further described and explained with reference to the accompanying drawings and specific embodiments; it should be noted that, if "first" or "second" is described in the text, it is used to distinguish different components, and the like, and does not represent the order of precedence, and does not limit "first" and "second" to be different types.

Obviously, the embodiments described below are only a part of the embodiments of the present invention, and not all of them; based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present invention.

Example 1

As shown in fig. 1, the metal-based rigid-flex board shown in this embodiment includes a metal base 1, and a first rigid board 2, a second rigid board 3, and a flexible board 4, which all have at least one layer of circuit 20, where the flexible board 4 includes rigid-flex areas 41 on both sides and a flexible board area 42 in the middle, protective films 5 are disposed on both side surfaces of the flexible board area 42, a groove 11 is disposed on the metal base 1, the flexible board 4 is disposed in the groove 11, a dielectric layer 6 is disposed between the flexible board 4 and the metal base 4, the first rigid board 2 and the second rigid board 3 are respectively bonded to the upper and lower surfaces of the metal base 1 through the dielectric layer 6, and windows 7 are disposed on the first rigid board 2, the second rigid board 3, and the metal base 1 at positions corresponding to the flexible board area 42 to expose the protective films 5, thereby achieving bending performance of the flexible board at the flexible board area; in the foregoing, the soft board is placed in the groove of the metal base and then combined with the hard board to form the rigid-flexible board, so that the metal base with excellent heat dissipation performance is added in the middle of the rigid-flexible board, the metal base is utilized to dissipate heat of the board, the heat dissipation performance of the board is effectively improved, and the problem that the existing FR4 board is poor in heat dissipation performance is solved.

In this embodiment, the metal-based rigid-flex board further includes a first via hole 8 for vertically conducting the circuits on the first hard board 2, the soft board 4 and the second hard board 3, a first copper plating layer 81 for conducting is disposed on a hole wall of the first via hole 8, and a dielectric layer 6 is disposed between the first copper plating layer 81 and the metal base 1, that is, the first via hole is not connected and conducted with the metal base.

In this embodiment, the metal-based rigid-flex board further includes a second via hole 9 for vertically conducting the circuits on the first hard board 2 and the second hard board 3, a second copper plating layer 91 for conducting is disposed on a hole wall of the second via hole 9, and a dielectric layer 6 is disposed between the second copper plating layer 91 and the metal base 1, that is, the second via hole is not connected and conducted with the metal base.

In this embodiment, the metal-based rigid-flex printed circuit board further includes a third via hole 10 for vertically conducting the circuits on the first hard board 2 and the second hard board 3, a third copper plating layer 101 for conducting is disposed on a hole wall of the third via hole 10, and the third copper plating layer 101 is in contact with the metal base 1, that is, the third via hole is connected and conducted with the metal base, so that the heat conduction efficiency is improved.

In this embodiment, the metal-based rigid-flex printed circuit board further includes a fourth via hole 12 for vertically conducting the circuits on the first hard board 2, the soft board 4 and the second hard board 3, a fourth copper plating layer 121 for conducting is disposed on a hole wall of the fourth via hole 12, and the fourth copper plating layer 121 is conducted with the metal base 1, that is, the fourth via hole is connected and conducted with the metal base, so that the heat conduction efficiency is improved.

In other embodiments, the first hard board, the second hard board and the flexible board each include two layers of wires thereon.

In other embodiments, the size of the single side of the protective film is 0.5-1mm larger than that of the soft board area, so that the edge of the protective film is pressed by the dielectric layer to ensure that the protective film does not fall off.

In other embodiments, the metal matrix is copper-based or aluminum-based.

In other embodiments, the dielectric layer is a PP dielectric layer.

Example 2

As shown in fig. 2, the method for producing a metal-based rigid-flex board in this embodiment is used to manufacture the metal-based rigid-flex board in embodiment 1, and sequentially includes the following processing steps:

(1) cutting: a metal substrate, a first PP sheet, a second PP sheet, a third PP sheet, a soft board, a first hard board and a second hard board are cut according to the size of a jointed board, the soft board comprises soft and hard combination areas on two sides and a soft board area in the middle, the soft board is a double-sided copper-clad core board with a dielectric layer being PI, the first hard board and the second hard board are double-sided copper-clad core boards with dielectric layers being FR4, the thickness of the first hard board and the second hard board is 0.5mm (excluding the thickness of an outer copper layer), and the thickness of copper layers on two sides of the first hard board and the second hard board is 0.5oz or 1 oz.

(2) Manufacturing an inner layer circuit (negative film process): respectively coating photosensitive films on the soft board, the first hard board and the second hard board by using a vertical coating machine, controlling the film thickness of the photosensitive films to be 8 mu m, completing inner layer circuit exposure on each board by using a full-automatic exposure machine and using 5-6 exposure rulers (21 exposure rulers), and forming an inner layer circuit graph after development; etching the inner layer, etching a circuit on the exposed and developed plate, and then removing the film; and (4) inner layer AOI, and then, detecting defects of an inner layer circuit, such as open short circuit, circuit notch, circuit pinhole and the like, and performing defect scrapping treatment, wherein a defect-free product is discharged to the next flow.

(3) Film pasting: and pasting a protective film at the area of the soft board on the soft board, wherein the size of the single side of the protective film is 0.5-1mm larger than that of the area of the soft board, so that the edge of the protective film is pressed by the dielectric layer in the later stage.

(4) Primary drilling: and respectively drilling a first through hole and a second through hole on the metal matrix.

(5) Routing grooves of a metal substrate: the depth of a groove for accommodating the soft board is controlled on the metal base, and the depth of the groove is controlled to be 2/3-3/4 of the thickness of the metal base; the first through hole is located in the groove area, and the second through hole is located outside the groove area.

(6) Windowing: and windowing the positions of the first PP sheet and the second PP sheet corresponding to the soft board area, wherein the size of the window is 0.5-1mm smaller than that of the protective film on one side, so that the soft board area can be conveniently uncovered and exposed in the later period.

(7) And (3) laminating: the metal base and each plate are firstly subjected to blackening or browning treatment, the browning speed is browned according to the thickness of copper at the bottom, then the soft plate is firstly placed in the groove on the metal base, the second PP sheet is arranged between the bottom of the soft plate and the bottom of the groove, then the first PP sheet and the first hard plate are sequentially overlapped on the upper surface of the metal base from inside to outside, the third PP sheet and the second hard plate are sequentially overlapped on the lower surface of the metal base from inside to outside, and then pressing is carried out to form the production plate.

(8) Secondary drilling: the production plate is subjected to blackening or browning removing treatment to remove a browning layer or a blackening layer on the production plate, then drilling is carried out by utilizing drilling data, through holes with the hole diameters smaller than that of the through holes are coaxially drilled at positions, corresponding to the first through hole and the second through hole, on the production plate, the rear parts of the two hole metallizations are in contact conduction with the metal base at the later stage, then the through holes are metallized through copper deposition and full-plate electroplating in sequence, and a first through hole and a second through hole are formed; still bore the through-hole that runs through first hard board, metal base and second hard board and run through first hard board, soft board, metal base and second hard board from top to bottom on producing the board, form third via hole and fourth via hole respectively after through heavy copper and full board electricity plate metallization, the third via hole is used for leading through first hard board, metal base and second hard board, and the fourth via hole is used for leading through first hard board, soft board, metal base and second hard board.

(9) Manufacturing an outer layer circuit (negative film process): transferring an outer layer pattern, coating a photosensitive film by using a vertical coating machine, controlling the film thickness of the photosensitive film to be 8 mu m, completing outer layer circuit exposure on a production plate by using a full-automatic exposure machine and 5-6 exposure rulers (21 exposure rulers), and forming an outer layer circuit pattern after development; etching the outer layer, namely etching the exposed and developed production board to form an outer layer circuit, wherein the width of the outer layer circuit is measured to be 3 mil; and (4) performing outer layer AOI, then checking the defects of an outer layer circuit, such as open short circuit, circuit notch, circuit pinhole and the like, performing defective scrapping treatment, and discharging a defect-free product to the next flow.

(10) And manufacturing a solder mask layer and silk-screen characters: spraying solder resist ink on the surface of a production board except a solder resist windowing position, sequentially carrying out pre-curing, exposure, development and thermosetting treatment to solidify the solder resist ink into a solder resist layer, and adopting spraying printing TOP surface solder resist ink, wherein characters on the TOP surface are added with a UL mark, so that a protective layer which prevents bridging between circuits during welding and provides a permanent electrical environment and chemical corrosion resistance is coated on circuits and base materials which do not need to be welded, and the protective layer plays a role in beautifying the appearance

(11) Surface treatment (nickel-gold deposition): the copper surface of the welding pad at the solder stop windowing position is communicated with a chemical principle, a nickel layer and a gold layer with certain required thickness are uniformly deposited, and the thickness of the nickel layer is as follows: 3-5 μm; the thickness of the gold layer is as follows: 0.05-0.1 μm.

(12) And electrical test: testing the electrical conduction performance of the finished board, wherein the board use testing method comprises the following steps: and (5) flying probe testing.

(13) And uncovering: and finally, deeply cutting and uncovering by using a laser and a gong machine to remove the outer core material on the production board corresponding to the soft board area so as to expose the protective film on the inner soft board area.

(14) And forming: according to the prior art and according to the design requirement, routing the shape, and obtaining the metal-based rigid-flex board with the tolerance of +/-0.05 mm.

(15) FQC: and (4) inspecting the appearance of the finished board according to the customer acceptance standard and the inspection standard of my department, and timely repairing the finished board if a defect exists so as to ensure that excellent quality control is provided for the customer.

(16) FQA: and measuring whether the appearance, the hole copper thickness, the dielectric layer thickness, the green oil thickness, the inner layer copper thickness and the like of the finished board meet the requirements of customers or not.

(16) And packaging: and hermetically packaging the finished boards according to the packaging mode and the packaging quantity required by the customer, putting a drying agent and a humidity card, and then delivering.

In other embodiments, the metal matrix is copper-based or aluminum-based.

The technical solutions provided by the embodiments of the present invention are described in detail above, and the principles and embodiments of the present invention are explained herein by using specific examples, and the descriptions of the above embodiments are only applicable to help understand the principles of the embodiments of the present invention; meanwhile, for a person skilled in the art, according to the embodiments of the present invention, there may be variations in the specific implementation manners and application ranges, and in summary, the content of the description should not be construed as a limitation to the present invention.

Claims (9)

1. The utility model provides a metal matrix soft or hard combination board, its characterized in that includes the metal base and all has first hard board, second hard board and the soft board of at least one deck circuit, the soft board includes the soft or hard combination region of both sides and middle soft board region, the regional both sides surface of soft board all is equipped with the protection film, be equipped with the recess on the metal base, the soft board is arranged in the recess, just the soft board with be equipped with the dielectric layer between the metal base, first hard board and second hard board are located through the dielectric layer bonding respectively the upper and lower surface of metal base, just on first hard board, second hard board and the metal base corresponding the regional department of soft board all is equipped with the windowing to show the protection film.

2. The metal-based rigid-flex board according to claim 1, further comprising a first via hole for vertically conducting the circuits on the first rigid board, the flexible board and the second rigid board, wherein a first copper plating layer for conducting is arranged on a hole wall of the first via hole, and a dielectric layer is arranged between the first copper plating layer and the metal base.

3. The metal-based rigid-flex board according to claim 1, further comprising a second via hole for vertically conducting the circuits on the first rigid board and the second rigid board, wherein a second copper plating layer for conducting is arranged on a hole wall of the second via hole, and a dielectric layer is arranged between the second copper plating layer and the metal base.

4. The metal-based rigid-flex board according to claim 1, further comprising a third via hole for vertically conducting the circuits on the first and second hard boards, wherein a third copper plating layer for conducting is provided on a hole wall of the third via hole, and the third copper plating layer is conducted with the metal base.

5. The metal-based rigid-flex board according to claim 1, further comprising a fourth via hole for vertically conducting the circuits on the first rigid board, the flexible board and the second rigid board, wherein a fourth copper plating layer for conducting is arranged on a hole wall of the fourth via hole, and the fourth copper plating layer is conducted with the metal base.

6. The metal-based rigid-flex board according to claim 1, wherein the first rigid board, the second rigid board and the flexible board each comprise two layers of wires.

7. The metal-based rigid-flex board according to claim 1, wherein the size of the protective film is 0.5-1mm larger than the size of the flexible board area on one side.

8. The metal-based rigid-flex board according to claim 1, wherein the metal matrix is copper-based or aluminum-based.

9. The metal-based rigid-flex board according to claim 1, wherein the dielectric layer is a PP dielectric layer.

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