Rigid-flex printed cable with electromagnetic compatibility

Abstract

The invention relates to an electromagnetic compatible rigid-flex printed cable, which comprises a rigid-flex printed board and two electric connectors (1), the rigid-flex printed board is divided into a rigid component (200) and a flexible component (300), each electric connector (1) comprises a shell (111), a contact pin (112) and a base (113), the base (113) is used for fixing the contact pin (112), and the shell (111) is connected with the base (113) and is used for protecting the contact pin (112) and the base (113); the rigid-flex printed cable is characterized in that the rigid parts (200) are arranged on the outer sides of the two ends of the rigid-flex printed board, the rigid parts (200) and the flexible parts (300) in the rigid parts (200) form two rigid areas (2) at the two ends of the rigid-flex printed board, the contact pins and the welding spots of the electric connector are fixedly sealed, and the shielding adhesive tape after being fixedly sealed is wound, so that the welding spots can be prevented from being affected with damp, and the insulation performance of the rigid-flex printed cable is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of rigid-flex printed cables, and in particular relates to an electromagnetically compatible rigid-flex printed cable. Background Art

[0002] Rigid-flex printed cables are composed of a rigid-flex printed board and an electrical connector, where the rigid-flex printed board and the electrical connector are fixed by pin welding. Rigid-flex printed cables are gradually being used in the aerospace field due to their great advantages of being light and thin.

[0003] However, rigid-flex printed cables cannot achieve 360° shielding like traditional cables using shielded conductors to improve the overall electromagnetic shielding effect of the product, and the welding pins of the electrical connector also affect the electromagnetic compatibility of the rigid-flex printed cables. Currently, the market will improve the shielding ability of rigid-flex printed boards by adding a shielding layer to the rigid-flex printed boards, which not only greatly increases the weight of the product, but also cannot achieve 360° shielding of the product, and does not consider the electromagnetic compatibility design method of the welding pins of the electrical connector.

[0004] Through the search of published patent documents, no published invention patent documents related to the present invention application have been found. Summary of the invention

[0005] The present invention aims to provide an electromagnetically compatible rigid-flexible printed cable to achieve nearly 360° shielding of the rigid-flexible printed cable.

[0006] An electromagnetic compatible rigid-flexible printed cable comprises a rigid-flexible printed circuit board and two electrical connectors 1, wherein the rigid-flexible printed circuit board is further divided into a rigid component 200 and a flexible component 300, and the electrical connector 1 comprises a shell 111, a pin 112 and a base 113, wherein the base 113 is used to fix the pin 112, and the shell 111 is connected to the base 113 to protect the pin 112 and the base 113; the characteristic is that the rigid component 200 is on the outside of both ends of the rigid-flexible printed circuit board, the rigid component 200 and the flexible component 300 therein form two rigid areas 2 at both ends of the rigid-flexible printed circuit board, the rigid area 2 is provided with a pad hole 21, the flexible component 300 is in the rigid-flexible printed circuit board and between the two rigid areas, and the bendable part of the flexible component 300 between the rigid areas 2 is a flexible area 3; the pin 112 of the electrical connector 1 is inserted into the pad hole 21, and the pin 112 is connected to the pad 21 of the rigid area 2 by welding to realize electrical signal transmission;

[0007] The flexible area 3 includes a soft board cover film 31 and a double-sided flexible board 32;

[0008] The double-sided flexible board 32 is composed of copper wires 321 and insulating layers 322. The copper wires 321 are divided into signal copper wires 10, differential signal copper wires 11, and shielding copper wires 9 according to the types of signals transmitted; the shielding copper wires 9 are laid on the left and right sides of the signal copper wires 10 and differential signal copper wires 11;

[0009] The rigid region 2 sequentially includes a rigid board 22, a prepreg 23, a PI protective film 24, a flexible board covering film 31, and a double-sided flexible board 32 from the outside to the inside;

[0010] A silver film 4 is attached to the outside of the flexible region 3.

[0011] Further, a square hole 8 is formed in the flexible component 300, that is, the flexible board covering film 31 is removed at the square hole 8, so that the shielding copper wire 9 of the double-sided flexible board is connected to the silver film 4 to achieve electromagnetic shielding of the flexible region 3.

[0012] Further, the welding part of the pin 112 of the electrical connector 1 is sealed with a sealing glue 5, and the rigid region 2 and the sealing colloid 5 are wound with a shielding tape 6 and are lapped with the electrical connector housing 111 at 360°.

[0013] Further, the rigid component 200 is provided with a through hole 7 to connect and conduct the shielding copper wires of each layer.

[0014] Further, the thickness of the silver film is ≥5μm and ≤15μm.

[0015] Further, the type of the sealing colloid 5 is a non-conductive epoxy glue, and the sealing height is ≥2mm from the tip of the pin of the electrical connector.

[0016] Further, the shielding tape 6 winds the electrical connector housing, the rigid component, and the sealing colloid in a 1 / 2 lap winding manner without non-connected gaps.

[0017] Further, the area of the upper square hole 8 is ≥4mm 2 , and the number of through holes 7 provided in the rigid component is ≥1, and the diameter of the through hole is ≤30 mil.

[0018] Further, the shielding copper wire 9 is a grid copper or a solid copper. The solid copper is selected for the layer where the differential signal with matching impedance requirements is located, and the grid copper is used for other layers.

[0019] Further, the distance between the shielding copper wire 9 and the edge of the printed circuit board is ≥10 mil, the width of the shielding copper wire 9 is ≥10 mil, and the distance between the signal line and the shielding copper is ≥10 mil.

[0020] The present invention can at least achieve one of the following beneficial effects:

[0021] (1) The present invention can improve the electromagnetic compatibility effect between signals, between rigid-flex printed cables, between rigid-flex printed cables and devices, and between entire devices.

[0022] (2) The electromagnetic compatibility design method of the rigid-flex printed cable of the present invention does not add a flexible layer to the rigid-flex printed cable, has little influence on the bending performance of the flexible component, and ensures the bendability of the rigid-flex printed cable.

[0023] (3) The encapsulation of the pins and solder joints of the electrical connector and the winding of the shielding tape after encapsulation of the present invention can prevent the solder joints from getting damp and improve the insulation performance of the rigid-flex printed cable. Description of the Drawings

[0024] The drawings are only for the purpose of illustrating the embodiments and are not considered to be a limitation of the present invention. Throughout the drawings, the same reference signs denote the same components.

[0025] Figure 1 is a schematic structural diagram of the rigid-flex printed board of the present invention;

[0026] Figure 2 is a schematic diagram of the rigid region 2 and the flexible region 3 of the rigid-flex printed board of the present invention;

[0027] Figure 3 is a schematic longitudinal sectional view of the rigid-flex printed cable of the present invention;

[0028] Figure 4 is a schematic transverse sectional view of the rigid-flex printed cable of the embodiment of the present invention;

[0029] Figure 5 is a schematic top view of the rigid-flex printed board of the embodiment of the present invention;

[0030] Figure 6 is a schematic local longitudinal sectional structure diagram of the rigid region of the embodiment of the present invention;

[0031] Figure 7 is a schematic local longitudinal sectional structure diagram of the flexible region of the embodiment of the present invention;

[0032] Figure 8 is a schematic structural diagram of the double-sided flexible board of the embodiment of the present invention;

[0033] Figure 9 is a schematic diagram of the flexible region with a silver film attached in the embodiment of the present invention;

[0034] Figure 10 is a schematic structural diagram of the electrical connector 1 in the embodiment of the present invention;

[0035] Reference Signs:

[0036] 1 is an electrical connector, 2 is a rigid region, 3 is a flexible region, 4 is a silver film, 5 is a potting adhesive, 6 is a shielding tape, 7 is a through hole, 8 is a square hole, 9 is a shielding copper wire, 10 is a signal copper wire, 11 is a differential signal copper wire, 21 is a pad hole, 22 is a rigid board, 23 is a prepreg, 24 is a PI protective film, 31 is a flexible board cover film, 32 is a double-sided flexible board, 111 is an electrical connector housing, 112 is an electrical connector pin, 113 is an electrical connector base, 321 is a copper wire, 322 is an insulating layer. Detailed implementation mode

[0037] The present invention is achieved through the following technical solutions.

[0038] An electromagnetic compatibility rigid-flex printed cable includes a rigid-flex printed board and an electrical connector 1. The rigid-flex printed board is further divided into a rigid component and a flexible component. The electrical connector includes a housing 111 and pins 112. The rigid component is on the outside, forming a rigid region 2, and the flexible component is between the inner layer and the rigid region, forming a bendable flexible region 3. The electrical connector 1 is connected to the rigid region by pin welding to achieve electrical signal transmission.

[0039] Further, a silver film 4 is pasted on the outside of the flexible region, and a square hole 8 is opened on the flexible component to connect with the silver film.

[0040] Further, the pin welding part of the connector is potted with a potting adhesive 5, and the electrical connector housing, the rigid component and the potted colloid are wound with a shielding tape 6. Further, a hole is opened at the silver film near the connector to overlap with the shielding tape.

[0041] Further, shielding copper 9 is laid on the left and right sides of the signal line 10 and the differential signal line 11.

[0042] Further, through holes 7 are provided in the rigid component to connect the shielding copper of each layer.

[0043] The electromagnetic compatibility design method of the rigid-flex printed cable described above is characterized in that: the thickness of the silver film is ≥5μm and ≤15μm.

[0044] The electromagnetic compatibility design method of the rigid-flex printed cable described above is characterized in that: the type of the potting adhesive is a non-conductive epoxy adhesive, and the potting height is based on the non-leakage connector pins.

[0045] The electromagnetic compatibility design method of the rigid-flex printed cable described above is characterized in that: the shielding tape winds the rigid region and the potted colloid in a 1 / 2 lap winding manner, is in full contact with the electrical connector housing, and there is no unconnected gap.

[0046] The electromagnetic compatibility design method of the rigid-flex printed cable described above is characterized in that: the area of the square hole 8 opened above is ≥4mm2 。

[0047] The electromagnetic compatibility design method of the rigid-flex printed cable is characterized in that the number of vias 7 provided in the rigid component is ≥1, and the diameter of the via is ≤30 mil.

[0048] The electromagnetic compatibility design method of the rigid-flex printed cable is characterized in that the shielding copper wire is grid copper or solid copper. Solid copper wire is selected for the layer where differential signals with matching impedance requirements are located, and grid copper wire is used for other layers.

[0049] The electromagnetic compatibility design method of the rigid-flex printed cable is characterized in that the distance between the shielding copper and the edge of the printed board is ≥10 mil, the width of the shielding copper is ≥10 mil, and the distance between the signal line and the shielding copper is ≥10 mil.

[0050] An electromagnetic compatible rigid-flex printed cable design method according to the above technical solution includes the following steps:

[0051] Step 1: Design and determine the type of shielding copper, the distance between the shielding copper and the edge of the printed board, the width of the shielding copper, and the distance between the signal line and the shielding copper;

[0052] Step 2: Design and determine the number and diameter of vias provided in the rigid component;

[0053] Step 3: Design and determine the area of the square holes opened on the flexible component;

[0054] Step 4: Paste a silver film on the flexible component;

[0055] Step 5: Determine the type of potting adhesive;

[0056] Step 6: Wind the rigid component and the potted colloid with shielding tape and lap with the electrical connector housing.

[0057] Shielding copper wires 9 are laid on the left and right sides of the signal copper wire 10 and the differential signal copper wire 11.

[0058] The following specifically describes the preferred embodiments of the present invention with reference to the accompanying drawings. The accompanying drawings form a part of the present invention and are used together with the embodiments of the present invention to explain the principle of the present invention, and are not used to limit the scope of the present invention.

[0059] Embodiment 1

[0060] An embodiment of the present invention, as Figures 1 to 2 shown, discloses an electromagnetic compatibility design method for a rigid-flex printed cable, including nearly 360° shielding of the rigid-flex printed board and the connector solder joints.

[0061] In this embodiment, electromagnetic shielding of the intermediate flexible component is achieved by attaching silver films 4 to the upper and lower outer sides of the flexible area; electromagnetic crosstalk between signals is achieved by laying shielding copper between signals; through holes are provided in the rigid component to reduce the signal return path and reduce electromagnetic compatibility radiation of the signals; by winding shielding tape 6 around the rigid component and the encapsulating colloid and lapping with the electrical connector housing, electromagnetic reception and radiation caused by the exposure of the pins of the rigid-flex printed cable are reduced.

[0062] An embodiment of the present invention discloses an electromagnetic compatibility design method for a rigid-flex printed cable in Embodiment 1, including the following steps:

[0063] Step 1: Design and determine the type of shielding copper, the distance between the shielding copper and the edge of the printed board, the width of the shielding copper, and the distance between the signal line and the shielding copper:

[0064] In this embodiment, exemplarily, the shielding copper is solid copper, the distance between the shielding copper and the edge of the printed board is 30 mil, the width of the shielding copper is 60 mil, and the distance between the signal line and the shielding copper is 10 mil.

[0065] Step 2: Design and determine the number and diameter of the through holes provided in the rigid component:

[0066] In this embodiment, exemplarily, the number of through holes provided in the rigid component is 6, and the diameter of the through holes is 20 mil.

[0067] Step 3: Design and determine the area of the square holes opened on the flexible component:

[0068] In this embodiment, exemplarily, the area of the square holes is 50 mm 2 .

[0069] Step 4: Attach silver films to the flexible component:

[0070] In this embodiment, exemplarily, the thickness of the silver film selected is 7 μm.

[0071] Step 5: Determine the type of encapsulating colloid:

[0072] In this embodiment, exemplarily, the type of encapsulating colloid selected is RB283 - 01, and the encapsulating height is 2.8 mm.

[0073] Step 6: Wind shielding tape around the rigid component and the encapsulating colloid and lap with the electrical connector housing.

[0074] The copper wire described above is a relatively wide copper wire, also called the front copper.

[0075] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any within the technical scope disclosed by the present invention is within the protection scope of the present invention.

Claims

1. A rigid-flex printed cable with electromagnetic compatibility, comprising a rigid-flex printed board and an electrical connector, including a rigid-flex printed board and two electrical connectors (1), wherein the rigid-flex printed board is further divided into a rigid component (200) and a flexible component (300), and the electrical connector (1) includes a housing (111), a pin (112) and a base (113), the base (113) is used to fix the pin (112), and the housing (111) is connected to the base (113) for protecting the pin (112) and the base (113); it is characterized in that, The rigid component (200) is located outside both ends of the rigid-flex printed circuit board. The rigid component (200) and the flexible component (300) inside it form two rigid regions (2) at both ends of the rigid-flex printed circuit board. The rigid regions (2) are provided with pad holes (21). The flexible component (300) is inside the rigid-flex printed circuit board and between the two rigid regions. The flexible component (300) forms a bendable part between the rigid regions (2) as the flexible region (3); The pin (112) of the electrical connector (1) is inserted into the pad hole (21), and the pin (112) is connected to the pad (21) of the rigid region (2) by soldering to achieve electrical signal transmission; The flexible region (3) includes a flexible board cover film (31) and a double-sided flexible board (32); The double-sided flexible board (32) is composed of copper wires (321) and insulating layers (322). The copper wires (321) are divided into signal copper wires (10), differential signal copper wires (11), and shielding copper wires (9) according to the type of transmitted signal; Shielding copper wires (9) are laid on the left and right sides of the signal copper wires (10) and differential signal copper wires (11); The rigid region (2) sequentially includes a rigid board (22), a prepreg (23), a PI protective film (24), a flexible board cover film (31), and a double-sided flexible board (32) from the outside to the inside; A silver film (4) is pasted on the outside of the flexible region (3).

2. The flexible-rigid printed cable with electromagnetic compatibility according to claim 1, wherein A square hole (8) is opened on the flexible component (300), that is, the flexible board cover film (31) is removed at the square hole (8) to connect the shielding copper wire of the double-sided flexible board to the silver film (4) to achieve electromagnetic shielding of the flexible region (3).

3. The flexible-rigid printed cable with electromagnetic compatibility according to claim 1, wherein The soldering joint of the pin (112) of the electrical connector (1) is sealed with a sealing adhesive (5), and the rigid region (2) and the sealing colloid (5) are wound with a shielding tape (6) and lap-jointed with the electrical connector housing (111) at 360°.

4. The flexible-rigid printed cable with electromagnetic compatibility according to claim 1, characterized in that, The rigid component (200) is provided with a through hole (7) to connect and conduct the shielding copper wires of each layer.

5. An electromagnetic compatibility rigid-flex printed cable according to claim 1, characterized in that The thickness of the silver film is ≥5μm and ≤15μm.

6. An electromagnetic compatibility rigid-flex printed cable according to claim 1, characterized in that, The type of the sealing colloid (5) is a non-conductive epoxy adhesive, and the sealing height is ≥2mm from the tip of the pin of the electrical connector.

7. An electromagnetic compatibility rigid-flex printed cable according to claim 1, characterized in that, The way of winding the shielding tape (6) around the electrical connector housing, the rigid component, and the sealing colloid is a 1 / 2 lap winding method without non-connected gaps.

8. An electromagnetic compatibility rigid-flex printed cable according to claim 1, characterized in that, The area of the upper square hole (8) described is ≥ 4 mm 2 , and the number of through holes (7) provided in the rigid component described is ≥ 1, and the diameter of the through hole is ≤ 30 mils.

9. An electromagnetic compatibility rigid-flex printed cable according to claim 1, characterized in that, The shielding copper wire (9) is a grid copper or a solid copper. The solid copper is selected for the layer where the differential signal with matching impedance requirements is located, and the grid copper is used for other layers.

10. A rigid-flex printed cable with electromagnetic compatibility according to claim 1, characterized in that The distance between the shielding copper wire (9) and the edge of the printed circuit board is ≥10mil, the width of the shielding copper wire (9) is ≥10mil, and the distance between the signal line and the shielding copper is ≥10mil.

Images