CN218388062U - Stiffening plate and rigid-flexible board - Google Patents

Abstract

The application relates to the technical field of printed circuit boards, provides a stiffening plate and rigid-flex board, and the stiffening plate includes: the aluminum plate unit is provided with two opposite first surfaces and second surfaces, the first surfaces and the second surfaces are both provided with placing grooves, and the two placing grooves are arranged in a reverse manner; the two BT resin substrates are respectively placed in the two placing grooves, thermosetting adhesive is arranged between the BT resin substrates and the bottoms of the placing grooves, and the shapes of the BT resin substrates are matched with the shapes of the placing grooves. The reinforcing plate can better meet the requirements of the rigid-flex board on high-frequency and high-speed performance.

Description

Stiffening plate and rigid-flexible board

Technical Field

The application relates to the technical field of printed circuit boards, in particular to a reinforcing plate and a rigid-flex board.

Background

In many cases, a reinforcing plate is bonded to one side of a flexible board in order to provide rigidity and a fixed support to the flexible board. With the rapid development of 5G technology in recent years, the requirements of the rigid-flex board on the high-frequency high-speed performance of the rigid-flex board during design are also increasing, and the traditional rigid-flex board manufacturing scheme is basically to improve the rigid-flex board only to improve the high-frequency high-speed performance, and the requirement of the rigid-flex board on the high-frequency high-speed performance is difficult to meet in this way.

SUMMERY OF THE UTILITY MODEL

The application provides a stiffening plate and rigid-flex board to satisfy the rigid-flex board better to the demand of high frequency high speed performance.

In one aspect, an embodiment of the present application provides a stiffening plate, including:

the aluminum plate unit is provided with two opposite first surfaces and second surfaces, the first surfaces and the second surfaces are provided with placing grooves, and the two placing grooves are arranged in an opposite mode;

the two BT resin substrates are respectively placed in the two placing grooves, thermosetting adhesive is arranged between the BT resin substrates and the bottoms of the placing grooves, and the shapes of the BT resin substrates are matched with the shapes of the placing grooves.

In some of these embodiments, one side of the first face has a first chamfered portion and one side of the second face has a second chamfered portion opposite the first chamfered portion.

In some of these embodiments, the first and second chamfered portions are each beveled or rounded.

In some of these embodiments, the first chamfer and the second chamfer are each beveled, the angle of the bevel being 18 ° -22 °, and the width of the bevel being 0.8mm-1.0mm.

In some embodiments, a matching portion is arranged on one side groove wall of the placing groove, a clamping portion is arranged at one end of the BT resin substrate, and the matching portion is connected with the clamping portion in a matching mode.

In some embodiments, the matching portion is provided as a projection, and the clamping portion is provided as a groove matched with the projection; or the matching part is arranged to be a groove, and the clamping part is arranged to be a convex block matched with the groove.

In some embodiments, the depth of the placing groove is 0.35mm-0.45mm, and the sum of the thicknesses of the BT resin substrate and the thermosetting adhesive is 0.36mm-0.44mm.

In some embodiments, the overall dimension of the placing groove is at least 0.1mm larger than the overall dimension of the BT resin substrate.

In another aspect, an embodiment of the present application provides a rigid-flex board including the reinforcing plate according to the first aspect.

In some embodiments, the rigid-flex board further includes two flexible boards, the reinforcing board is disposed between the two flexible boards, signal transmission dense regions are disposed on both of the two flexible boards, and the two BT resin substrates on the reinforcing board correspond to the signal transmission dense regions on the two flexible boards, respectively.

The embodiment of the application provides a stiffening plate, beneficial effect lies in: because the first surface and the second surface which are opposite to each other of the aluminum plate unit are respectively provided with the placing groove, the BT resin substrate is arranged in the placing groove, and the aluminum plate unit and the BT resin substrate are fixed together through thermosetting adhesive in a pressing mode, when the reinforcing plate is embedded into the soft and hard combination plate, the BT resin substrate can correspond to a signal transmission dense area on the soft and hard combination plate, so that the signal transmission performance of the signal transmission dense area on the soft and hard combination plate can be improved by utilizing the excellent heat resistance, excellent low dielectric property, low thermal expansion rate, good mechanical characteristics and the like of the BT resin substrate, the transmission loss of high-speed signals can be reduced, the problems of signal transmission blocking, loss and the like caused by long-time electric heating of golden fingers can be avoided, the requirement of the soft and hard combination plate on high-frequency high-speed performance can be better met, and better rigidity and fixed support can be provided for the soft and hard combination plate.

Compared with the beneficial effect of prior art, the soft and hard combination board that this application provided compares in prior art with what this application provided, and this is no longer repeated here.

Drawings

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

FIG. 1 is a schematic structural diagram illustrating a method for fabricating a stiffener according to one embodiment of the present disclosure;

FIG. 2 is a schematic view of a reinforcement plate according to one embodiment of the present application;

fig. 3 is a schematic structural view of a BT resin substrate in the reinforcing plate shown in fig. 2;

FIG. 4 is a schematic structural view of a rigid-flex board including the reinforcing plate shown in FIG. 2;

FIG. 5 is a schematic structural view of a mother plate including the aluminum plate unit in the reinforcing plate shown in FIG. 2;

fig. 6 is a schematic structural view of a first chamfered portion and a second chamfered portion of the reinforcing plate shown in fig. 2.

The meaning of the labels in the figures is:

10. an aluminum plate unit; 11. a first side; 111. a first chamfered portion; 12. a second face; 121. a second chamfered portion; 13. a placement groove; 131. a fitting portion; 20. a BT resin substrate; 21. a fastening part; 30. a motherboard; 40. a position avoiding groove; 50. a soft board; 51. a dense area of signal transmission.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

Reference throughout this specification to "one embodiment," "some embodiments," or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," or the like, in various places throughout this specification are not necessarily all referring to the same embodiment, but rather mean "one or more but not all embodiments" unless specifically stated otherwise. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

In order to explain the technical solution of the present application, the following description is made with reference to the specific drawings and examples.

Referring to fig. 1, fig. 2 and fig. 4, an embodiment of a first aspect of the present application provides a method for manufacturing a stiffening plate, including:

s100: an aluminum plate unit 10 is provided, the aluminum plate unit 10 has a first surface 11 and a second surface 12 which are opposite to each other, placing grooves 13 are arranged on the first surface 11 and the second surface 12, and the two placing grooves 13 are arranged oppositely.

Specifically, aluminum plate unit 10 is made of aluminum, for example, 7075T6 aluminum with high hardness and high strength may be selected to prevent aluminum plate unit 10 from deforming, and aluminum plate unit 10 may have undergone one drilling process, that is, aluminum plate unit 10 has drilled out peripheral holes, material number holes, and other positioning holes.

S200: two BT resin substrates 20 are placed in the two placing grooves 13, respectively, and thermosetting adhesive is provided between the BT resin substrates 20 and the groove bottoms of the placing grooves 13, and the shape of the BT resin substrates 20 is adapted to the shape of the placing grooves 13.

Specifically, a BT board with the copper thickness of 1/3OZ can be selected to reduce the material cost to the maximum extent, after cutting, the copper foils on the two sides of the BT board are etched to obtain the BT resin substrate 20, and then the BT resin substrate 20 is subjected to drilling treatment once, namely, a board edge peripheral hole and an anti-reflection hole for forming a routing board are drilled, wherein the aperture of the peripheral hole can be designed to be 3.0mm, and the BT resin substrate is used for positioning a pin sleeve when being adhered to a thermosetting adhesive in a false mode.

Optionally, each BT resin substrate 20 may be temporarily attached with 2 thermosetting adhesives with a thickness of 0.025mm, and during temporarily attaching, the positioning is performed after the pin pins are aligned with the peripheral holes of the BT resin substrate 20, and the temporarily attaching is performed by using a vacuum temporarily attaching machine.

Optionally, after the thermosetting adhesive is pasted, secondary drilling is performed on the BT resin substrate 20, the two drilling data are divided into a positive drilling data and a negative drilling data, and a reverse hole is drilled during primary drilling, so that the production condition of wrong data can be avoided, and a 1.45mm forming routing positioning hole in the BT resin substrate 20 plate is drilled during secondary drilling, wherein the positioning hole needs to be designed in a waste material area during final product production, and is prevented from being sunken after being pressed with a soft-hard combined plate.

Optionally, the BT resin substrate 20 is subjected to a cleaning dust treatment so that the BT resin substrate 20 is better bonded with the thermosetting adhesive at a later stage.

Alternatively, the overall dimension of the placement groove 13 is larger than the overall dimension of the BT resin substrate 20 by at least 0.1mm, so that the BT resin substrate 20 is placed in the placement groove 13.

Alternatively, the depth of the placement groove 13 is 0.35mm to 0.45mm, such as 0.35mm, 0.37mm, 0.39mm, 0.41mm, 0.43mm, 0.45mm, and the like, and the sum of the thicknesses of the BT resin substrate 20 and the thermosetting adhesive is 0.36mm to 0.44mm, such as 0.36mm, 0.38mm, 0.40mm, 0.42mm, 0.44mm, and the like. Therefore, the overall flatness of the aluminum plate unit 10 and the BT resin substrate 20 can be improved, and finally, the flatness of the surface of the finished product rigid-flex board after the reinforcing plate and the soft board 50 are laminated can be improved.

S300: the aluminum plate unit 10 is pressed together with the two BT resin substrates 20.

Specifically, the aluminum plate unit 10 and the two BT resin substrates 20 are put into a fast press for fast pressing, and the fast pressing and laminating manner adopts: 2.0mm silica gel pad + no silicon is from type membrane + aluminum plate unit 10 and two BT resin base plate 20+ no silicon is from type membrane +2.0 silica gel pad, wherein, use 2.0mm silica gel pad can fully fill the height difference condition of BT resin base plate 20 and aluminum plate unit 10 because of the depth control tolerance exists, ensure that BT resin base plate 20 can laminate to aluminum plate unit 10 completely, thereby improve the binding rate between the two, further improve product reliability, use no silicon from type membrane can avoid appearing the silicon oil material because of high temperature in-process at the fast pressing, lead to remaining the silicon oil material on aluminum plate unit 10 surface after the fast pressing, finally influence the pressfitting reliability of stiffening plate and soft and hard combination board.

S400: and curing the thermosetting adhesive.

Specifically, the aluminum plate unit 10 and the two BT resin substrates 20 after being pressed together may be subjected to 150 ° +2 hour curing baking to completely cure the thermosetting adhesive.

In the method for manufacturing a reinforcing plate according to the embodiment of the application, since the placing grooves 13 are disposed on the first surface 11 and the second surface 12 of the aluminum plate unit 10, the BT resin substrate 20 is disposed in the placing grooves 13, and the aluminum plate unit 10 and the BT resin substrate 20 are fixed together by thermosetting adhesive, when the reinforcing plate is embedded into the rigid-flex board, the BT resin substrate 20 can be made to correspond to the signal transmission dense region 51 on the rigid-flex board, for example, to correspond to the golden finger region on the rigid-flex board, so that the BT resin substrate 20 can utilize the excellent heat resistance, the excellent low dielectric property, the low thermal expansion rate, the good mechanical characteristics and other properties of the BT resin substrate 20, the transmission loss of high-speed signals can be reduced, the problems of signal transmission clamping, loss and the like caused by long-time electric heating of the golden finger can be avoided, the signal transmission performance of the signal transmission dense region 51 on the rigid-flex board can be improved, so as to better meet the requirements of the rigid-flex board on high-frequency high-speed performance, and better rigid and fixed support can be provided for the rigid-flex board.

Referring to fig. 4, in some embodiments, before providing an aluminum plate unit 10, the method for manufacturing a reinforcing plate further includes: the first surface 11 and the second surface 12 are respectively provided with a placing groove 13. For example, the placing grooves 13 may be machined on the first face 11 and the second face 12, respectively, using a gong machine.

Referring to fig. 2, fig. 3 and fig. 5, in some embodiments, in order to improve the production efficiency, the placing grooves 13 are respectively processed on the first surface 11 and the second surface 12, and specifically include:

first, a mother plate 30 is provided, and the mother plate 30 has a plurality of aluminum plate units 10 connected thereto.

Specifically, the mother sheet 30 has opposite front and back surfaces, the front surface being located on the same plane as the first surfaces 11 of all the aluminum sheet units 10, and the back surface being located on the same plane as the second surfaces 12 of all the aluminum sheet units 10. In this embodiment, the size of the mother board 30 is 500mm × 600mm, and peripheral holes, material number holes, and post-process routing positioning holes are drilled in the mother board 30.

Next, the placement grooves 13 on the first surfaces 11 of all the aluminum plate units 10 are machined.

Specifically, can paste the viscosity protection film in the one deck earlier in the reverse side of mother board 30 for carry out vacuum adsorption on the accuse deep gong machine, the protection film need cover all hole sites of mother board 30 face, in order to avoid leaking the vacuum during vacuum adsorption, reuse the accuse deep gong machine of coming out with standing groove 13 on the first face 11 of all aluminum plate units 10 processing after that, tear the protection film at the back after the processing is accomplished.

Next, the placement grooves 13 on the second surfaces 12 of all the aluminum plate units 10 are machined.

Specifically, can paste the viscosity protection film in the one deck in the front of mother board 30 earlier for carry out vacuum adsorption on the accuse deep gong machine, the protection film need cover all hole sites of 30 faces of mother board, in order to avoid leaking the vacuum during vacuum adsorption, reuse the accuse deep gong machine after that and process out with standing groove 13 on the second face 12 of all aluminum plate units 10, tear positive protection film after the processing is accomplished.

Finally, the plurality of aluminum plate units 10 are separated.

Specifically, the mother sheet 30 may be separated into a plurality of individual aluminum sheet units 10 using a stamping method.

Alternatively, after the plurality of aluminum plate units 10 are separated, the plurality of individual aluminum plate units 10 may be washed with high-pressure water to wash off aluminum powder and aluminum debris remaining on the aluminum plate units 10, and the plate surface may be cleaned.

By adopting the scheme, the placing grooves 13 on the first surface 11 and the second surface 12 of the aluminum plate units 10 can be processed only by twice processes, the processing efficiency is high, and the production cost is reduced.

Referring to fig. 2, 4 and 6, in some embodiments, in order to prevent the right-angled edge of the stiffening plate from breaking a line crossing the right-angled edge on the rigid-flexible printed circuit board when the stiffening plate is subsequently laminated with the rigid-flexible printed circuit board, which may result in abnormal mass scrap, one side of the first surface 11 has a first chamfered portion 111, one side of the second surface 12 has a second chamfered portion 121 opposite to the first chamfered portion 111, and both the first chamfered portion 111 and the second chamfered portion 121 may be chamfered or rounded. Therefore, the edges and corners of the first side edge and the second side edge can be prevented from being in direct contact with the circuit on the rigid-flex printed circuit board, and the breakage of the rigid-flex printed circuit board can be avoided.

It is to be understood that each of the first chamfered portion 111 and the second chamfered portion 121 may be provided in plurality.

In this embodiment, the first chamfer 111 and the second chamfer 121 are both beveled, the angle α of the beveling is 18 ° -22 °, such as 18 °, 20 °, and 22 °, and the width D is 0.8mm-1.0mm, such as 0.8mm, 0.9mm, and 1.0mm, and the beveling can be performed by using a diamond 70 ° beveling tool. Therefore, the direct contact between the edges of the first side edge and the second side edge and the circuit on the rigid-flex printed circuit board can be further avoided, and the fracture of the rigid-flex printed circuit board can be caused.

Referring to fig. 2, 3 and 5, in some embodiments, before providing an aluminum plate unit 10, the method for manufacturing a reinforcing plate further includes:

first, a mother plate 30 is provided, and the mother plate 30 has a plurality of aluminum plate units 10 connected thereto.

Specifically, the mother plate 30 has opposite front and back surfaces, the front surface being located on the same plane as the first surfaces 11 of all the aluminum plate units 10, and the back surface being located on the same plane as the second surfaces 12 of all the aluminum plate units 10.

Secondly, a plurality of clearance grooves 40 are processed on the mother plate 30, the clearance grooves 40 are arranged in one-to-one correspondence with the aluminum plate units 10, the clearance grooves 40 penetrate through the mother plate 30, and notches at two ends of the clearance grooves 40 are respectively provided with a first groove edge and a second groove edge.

Specifically, the avoiding groove 40 penetrates through the front surface and the back surface of the motherboard 30, the first groove edge and the second groove edge are both right-angle edges, the first groove edge and the second groove surface are respectively located on the front surface and the back surface of the motherboard 30, and when the motherboard is subsequently pressed with the rigid-flex board, the first groove edge and the second groove edge can cause the circuit crossing the first groove edge and the second groove edge on the rigid-flex board to break, so that the abnormal scrapping in batch is caused.

Next, the first groove sides of all the avoiding grooves 40 are chamfered so that the first chamfered portions 111 are formed on the first groove sides.

Specifically, a medium viscosity protective film may be attached to the reverse side of the mother board 30 for performing vacuum adsorption on the depth control gong machine, the protective film needs to cover all hole sites on the surface of the mother board 30 to prevent vacuum leakage during vacuum adsorption, and then the diamond bevel edge knife is used to perform chamfering processing on all first groove edges of the clearance groove 40 to form the first chamfer portion 111.

Then, the second groove sides of all the avoiding grooves 40 are chamfered so that the second chamfered portions 121 are formed on the second groove sides.

Specifically, a medium viscosity protective film may be first attached to the front surface of the mother board 30 for performing vacuum adsorption on the depth control gong machine, the protective film needs to cover all hole sites on the surface of the mother board 30 to prevent vacuum leakage during vacuum adsorption, and then the diamond bevel edge knife is used to perform chamfering processing on all second groove edges of the clearance groove 40 to form the second chamfer portion 121.

Finally, the plurality of aluminum plate units 10 are separated.

Specifically, the mother plate 30 may be separated into a plurality of individual aluminum plate units 10 using a stamping method.

With the above-described configuration, the processing efficiency of the first chamfered portion 111 and the second chamfered portion 121 can be improved.

Optionally, when chamfering the first groove edges of all the avoiding grooves 40, the placing grooves 13 on the first surfaces 11 of all the aluminum plate units 10 may be machined at the same time; when the second groove edges of all the avoiding grooves 40 are chamfered, the placing grooves 13 on the second surfaces 12 of all the aluminum plate units 10 can be machined at the same time.

In some embodiments, before providing an aluminum plate unit 10, the method for manufacturing a stiffening plate further includes: the aluminum plate unit 10 is subjected to anodic oxidation treatment. This can further improve the surface hardness of the aluminum plate unit 10 and prevent the plate surface from being scratched.

Alternatively, the mother substrate 30 may be subjected to an anodizing process.

In this example, the aluminum plate unit 10 was subjected to black anodizing.

Referring to fig. 1 to 6, an embodiment of a first aspect of the present application provides a method for manufacturing a stiffener, including:

1. sub-process

1. Processing flow of BT resin substrate 20: cutting → inner layer etching → one-step drilling → false pasting thermosetting adhesive

→ secondary drilling → shaping gong board → pre-lamination.

Wherein cutting: because conventional sony D3451 thermosetting adhesive width is fixed 250mm, for production efficiency and convenient batch production when guaranteeing false subsides thermosetting adhesive, BT board is opened material size design and is 250 x 300mm, compromise production efficiency when can guarantee the maximize utilization ratio.

Wherein, the inner layer is etched: the BT plate is a two-sided copper-clad plate, the BT plate with the thickness of 1/3OZ copper is selected during purchase, the material cost is reduced to the maximum extent, and the two-sided copper foil is etched after cutting to obtain the BT resin substrate 20.

Wherein once drilling: only drilling the peripheral hole at the edge of the board and the anti-reverse hole for forming the routing board in one drilling process, dividing two drilling data of the front side and the back side, wherein the peripheral hole is designed to be 3.0mm and is used for positioning a sleeve pin when the thermal setting adhesive is stuck in a false mode.

Wherein the false pasting thermosetting adhesive: 2 pieces of 0.025mm thick Sony D3451 thermosetting adhesive are temporarily pasted on each BT resin substrate 20, positioning is carried out after pin nails are aligned with peripheral holes of the BT resin substrate 20 during temporary pasting, and temporary pasting is carried out by using a vacuum temporary pasting machine.

Wherein secondary drilling: two drilling data of positive and negative during secondary drilling, because the hole of preventing turning over has been bored during primary drilling, can avoid using wrong data production condition, the shaping gong board locating hole of 1.45mm in the board is bored during secondary drilling, and this locating hole needs the waste material region of design when final finished product to avoid producing the cave after with soft and hard combination board pressfitting.

Wherein the gong board of shaping: when the shaping gong board appearance is designed, increase a lug design under the condition that does not influence final finished product appearance, improve the production efficiency when embedding aluminum plate unit 10 to and play the effect that the level was prevented staying, prevent promptly that the locating hole of gong board from misplacing the direction.

Wherein the pre-stacking comprises the following steps: after molding, the BT resin substrate 20 is subjected to cleaning dust treatment before being embedded in the aluminum plate unit 10.

2. Thermosetting adhesive flow: cutting material → one-time drilling → false pasting of BT plate.

Wherein cutting: the width of the conventional Sony D3451 thermosetting adhesive is fixed to be 250mm, and for the false paste manufacturing of the matched BT resin substrate 20, the cutting size of the thermosetting adhesive is designed to be 250 x 300mm, so that the maximum utilization rate can be ensured, and the production efficiency can be considered.

Wherein once drilling: the anti-hole that prevents when only drilling the peripheral hole of board limit and shaping gong board once, divide two drilling data (also can understand that two thermosetting glues are attached in BT resin base plate 20 both sides, so the drilling data of positive and negative is different), the peripheral hole design is 3.0mm for cover pin when false with BT resin base plate 20 is fixed a position.

Wherein the dummy BT resin substrate 20: and C, false sticking of a BT resin base plate 20 to every 2 pieces of Sony D3451 thermosetting adhesive, positioning after aligning with peripheral holes of the BT resin base plate 20 by using pin nails during false sticking, and false sticking by using a vacuum false sticking machine.

3. Aluminum plate process: cutting → black anodizing → one time of drilling → one time of routing → reverse side film-sticking → front side depth control and bevel edge → one time of film tearing → front side film-sticking → back side depth control and bevel edge → secondary film tearing → high pressure water washing → pre-lamination.

Wherein cutting: in order to ensure that the whole large mother board 30 is not deformed and the depth control stability during double-sided depth control manufacturing, the mother board 30 is made of 7075T6 aluminum with higher hardness and strength, and the size is designed to be 500 x 600mm.

Wherein black anodic oxidation: the anodic oxidation does not limit the color, and the anodic oxidation can further improve the surface hardness of the mother substrate 30 and prevent the plate surface from being scratched.

Wherein, primary drilling: and drilling out peripheral holes, material number holes and post-process routing positioning holes.

Wherein once gong board: use ordinary gong machine to gong out a plurality of avoiding groove 40 in advance, the notch of avoiding groove 40 both ends has first trough edge and second trough edge respectively, compares and controls a plurality of avoiding groove 40 of gong out deeply on controlling dark gong machine, and the numerous and diverse flow of pasting the multilayer film can be removed from when its efficiency is higher.

Wherein, the reverse side is pasted with a film: before controlling depth on the front side, a medium viscosity protective film is required to be attached to the back side of the mother board 30 for vacuum adsorption on the depth control gong machine, and the protective film is required to cover all hole sites on the board surface to avoid vacuum leakage during vacuum adsorption.

Wherein the front controls depth and bevel edge: depth control manufacturing is carried out on a specific area of the aluminum plate according to engineering design data, all the placing grooves 13 on the first surface 11 of the aluminum plate unit 10 are machined, the depth of each placing groove 13 is required to be 0.35mm-0.45mm, the size of each placing groove 13 is 0.1mm larger than the whole forming size of the BT resin substrate 20, and each placing groove 13 is provided with a groove so as to correspond to a bump on the BT resin substrate 20; and chamfering the first groove edges of all the avoiding grooves 40 to form a first chamfer part 111 on each first groove edge, wherein the first chamfer part 111 is a chamfer angle, the angle alpha of the chamfer angle is 18-22 degrees, the width of the chamfer angle is 0.8-1.0 mm, and the chamfer angle is produced by using a diamond 70-degree bevel edge cutter.

Wherein, once tearing the membrane: after depth control and bevel edge control are completed on the front side, the protective film on the back side of the mother board 30 is torn off.

Wherein the front side is pasted with a film: after depth control is completed on the front side, a layer of middle adhesive protective film is required to be adhered to the front side of the mother board 30 before depth control is performed on the back side, the middle adhesive protective film is used for vacuum adsorption on the depth control gong machine, and the protective film is required to cover all hole sites on the board surface to avoid vacuum leakage during vacuum adsorption.

Wherein the back side depth control and bevel edge: the design method and the engineering data are manufactured by referring to the front depth control and bevel edge method.

Wherein the secondary dyestripping: after depth control and beveling are finished on the reverse side, the protective film on the front side of the mother board 30 is torn off, and the double-sided placing groove 13, the first chamfer part 111 and the second chamfer part 121 are manufactured.

Wherein, high-pressure water washing: washing with high pressure water to remove aluminum powder and aluminum scraps remained after the depth control and the bevel edge control of the mother board 30, and cleaning the board surface.

2. Main process

Embedding the BT resin substrate 20 → rapid pressing → curing and baking → shaping the gong board.

Wherein the BT resin substrate 20: tearing off the release film of thermosetting adhesive on the BT resin substrate 20, aligning the lug on the BT resin substrate 20 with the groove on the aluminum plate unit 10, and embedding the BT resin substrate 20 in the placing grooves 13 on the first surface 11 and the second surface 12 of the aluminum plate unit 10.

Wherein quick pressfitting: putting the aluminum plate unit 10 with the embedded panel BT resin base plate 20 on the two sides into a fast press for fast pressing, wherein the fast pressing and laminating mode adopts the following steps: 2.0mm silica gel pad + no silicon is from type membrane + embedded back aluminum plate + no silicon is from type membrane +2.0 silica gel pad, wherein, use 2.0mm silica gel pad can fully fill the height difference condition of BT resin base plate 20 and aluminum plate unit 10 because of the depth control tolerance exists, ensure that BT resin base plate 20 can laminate completely to aluminum plate unit 10, thereby improve the binding rate between the two, further improve product reliability, use no silicon from type membrane can avoid appearing the silicone oil material because of high temperature at the fast pressing in-process, lead to remaining the silicone oil material on aluminum plate unit 10 surface after the fast pressing, finally influence the pressfitting reliability of stiffening plate and soft and hard combination board.

Wherein, curing the baking plate: after the rapid pressing, a 150 degrees +2H curing baking plate is needed to completely cure the thermosetting adhesive.

Wherein the molding comprises the following steps: the molding process is performed according to the engineering design data.

Referring to fig. 2 and 4, a second aspect of the present disclosure provides a stiffening plate, which includes an aluminum plate unit 10 and two BT resin substrates 20.

The aluminum plate unit 10 has two opposite first surfaces 11 and second surfaces 12, the first surfaces 11 and the second surfaces 12 are both provided with placing grooves 13, and the two placing grooves 13 are arranged opposite to each other.

The two BT resin substrates 20 are respectively placed in the two placing grooves 13, thermosetting adhesive is provided between the BT resin substrates 20 and the groove bottoms of the placing grooves 13, and the shapes of the BT resin substrates 20 are matched with the shapes of the placing grooves 13.

According to the reinforcing plate provided by the embodiment of the application, since the placing grooves 13 are formed in the first surface 11 and the second surface 12 of the aluminum plate unit 10, the BT resin substrate 20 is arranged in the placing grooves 13, and the aluminum plate unit 10 and the BT resin substrate 20 are fixed together by thermosetting adhesive in a pressing manner, when the reinforcing plate is embedded into a rigid-flex board, the BT resin substrate 20 can be made to correspond to the signal transmission dense region 51 on the rigid-flex board, so that the excellent heat resistance, excellent low dielectric property, low thermal expansion rate, good mechanical characteristics and other properties of the BT resin substrate 20 can be utilized, the transmission loss of high-speed signals can be reduced, the problems of signal transmission blocking, loss and the like caused by long-time power-on heating of a gold finger can be avoided, the signal transmission property of the signal transmission dense region 51 on the rigid-flex board can be improved, the requirement of the rigid-flex board on high-frequency high-speed performance can be better met, and better rigidity and fixed support can be provided for the rigid-flex board.

Referring to fig. 2, fig. 3 and fig. 4, in some embodiments, a fitting portion 131 is disposed on a side wall of the placement slot 13, an engaging portion 21 is disposed at one end of the bt resin substrate 20, and the fitting portion 131 is in fit connection with the engaging portion 21.

By adopting the above-described configuration, when the two BT resin substrates 20 are placed in the two placing grooves 13, the BT resin substrates 20 can be prevented from being placed upside down by engaging and connecting the engaging portions 131 with the engaging portions 21.

Alternatively, the matching portion 131 is provided as a bump, and the engaging portion 21 is provided as a groove adapted to the bump; alternatively, the matching portion 131 is provided as a groove, and the engaging portion 21 is provided as a projection adapted to the groove.

In this embodiment, the matching portion 131 is a groove, and the engaging portion 21 is a protrusion adapted to the groove.

Referring to fig. 2, 3 and 4, an embodiment of a third aspect of the present application provides a rigid-flexible printed circuit board including a reinforcing plate according to the second aspect.

It is understood that the rigid-flex printed circuit board further includes two flexible boards 50, the reinforcing board is disposed between the two flexible boards 50, signal transmission dense regions 51 are disposed on both of the two flexible boards 50, and the two BT resin substrates 20 on the reinforcing board correspond to the signal transmission dense regions 51 on the two flexible boards 50, respectively.

According to the rigid-flex board provided by the embodiment of the application, the reinforcing board is arranged between the two soft boards 50, the signal transmission dense area 51 is arranged on the soft boards 50, the BT resin substrate 20 on the reinforcing board corresponds to the signal transmission dense area 51 on the soft boards 50, the placing grooves 13 are arranged on the first surface 11 and the second surface 12 which are opposite to the reinforcing board aluminum board unit 10, the BT resin substrate 20 is arranged in the placing groove 13, and the aluminum board unit 10 and the BT resin substrate 20 are fixed together through thermosetting adhesive in a pressing mode, so that the excellent heat resistance, the excellent low dielectric property, the low thermal expansion rate, the good mechanical characteristics and other properties of the BT resin substrate 20 can be utilized, the transmission loss of high-speed signals is reduced, the problems that the golden finger is jammed and lost in signal transmission caused by long-time power-on heating are avoided, the signal transmission performance of the signal transmission dense area 51 on the rigid-flex board is improved, the requirement of the rigid-flex board on the high-speed performance is better met, and better rigid and fixed support can be provided for the rigid-flex board.

The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.

Claims (10)

1. A stiffener, comprising:

the aluminum plate unit is provided with two opposite first surfaces and second surfaces, the first surfaces and the second surfaces are both provided with placing grooves, and the two placing grooves are arranged in a reverse manner;

the two BT resin substrates are respectively placed in the two placing grooves, thermosetting adhesive is arranged between the BT resin substrates and the bottoms of the placing grooves, and the shapes of the BT resin substrates are matched with the shapes of the placing grooves.

2. The stiffening plate of claim 1 wherein one side of the first face has a first chamfer and one side of the second face has a second chamfer opposite the first chamfer.

3. The stiffening plate of claim 2, wherein the first and second chamfered portions are each beveled or rounded.

4. The reinforcing panel of claim 3, wherein the first chamfered portion and the second chamfered portion are each beveled at an angle of 18 ° -22 °, and the width of the bevel is 0.8mm-1.0mm.

5. The reinforcing plate as claimed in claim 1, wherein a fitting portion is provided on one side wall of the placement groove, and a locking portion is provided at one end of the BT resin substrate, and the fitting portion is fitted and connected to the locking portion.

6. The stiffening plate of claim 5 wherein the engaging portion is configured as a protrusion and the engaging portion is configured as a groove adapted to the protrusion; or the matching part is arranged to be a groove, and the clamping part is arranged to be a convex block matched with the groove.

7. The reinforcing plate according to any one of claims 1 to 6, wherein the depth of the placement groove is 0.35mm to 0.45mm, and the sum of the thicknesses of the BT resin substrate and the thermosetting adhesive is 0.36mm to 0.44mm.

8. The reinforcing plate according to any one of claims 1 to 6, wherein the placing groove has an outer dimension at least 0.1mm larger than an outer dimension of the BT resin substrate as a whole.

9. A rigid-flex board, characterized in that the rigid-flex board comprises the reinforcing plate of any one of claims 1 to 8.

10. The rigid-flex board according to claim 9, further comprising two flexible boards, wherein the reinforcing board is disposed between the two flexible boards, each of the two flexible boards is provided with a signal transmission dense region, and the two BT resin substrates on the reinforcing board correspond to the signal transmission dense regions on the two flexible boards, respectively.

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