Manufacturing process of high-speed hybrid optical flexible cable

Abstract

The invention belongs to the technical field of cable manufacturing, and particularly relates to a manufacturing process of a high-speed hybrid optical flexible cable, which comprises the following process steps of: etching optical fiber channel patterns on bare copper or aluminum areas of at least one top flexible printed circuit board and a bottom flexible printed circuit board; the top flexible printed circuit board and the bottom flexible printed circuit board move synchronously and wrap the synchronously moving optical fiber, and the optical fiber is fixed in the optical fiber channel pattern through prepreg; and pressing and connecting the top flexible printed circuit board and the bottom flexible printed circuit board through a lamination process. By using the optical fiber channel pattern and the fixing tool, the optical fiber is fixed, and the special seam pattern is designed, so that the two flexible printed circuit boards can be butted, and the high-speed hybrid optical flexible cable with the length of hundreds of meters can be manufactured and is suitable for being used in various application scenes.

Description

Technical Field

[0001] The invention relates to the technical field of cable manufacturing, and in particular to a manufacturing process of a high-speed hybrid optical flexible cable. Background Art

[0002] In automotive ADAS systems, unmanned aerial vehicles (UAVs), drone systems, rocket systems, or missile systems, the distance between the sensor module and the processor can vary from a few meters to tens or hundreds of meters, depending on the actual system application or constraints. Existing applications may require routing optical fibers in arbitrary shapes and lengths. The state-of-the-art minimum fiber bend radius is about 3mm to 8mm different from the manufacturing specifications of major brands on the market today.

[0003] Due to the nature of the fiber's flexible inertia, it is often difficult to place the fiber on a pre-designed trace without firmly securing it. If the fibers are not firmly secured during the manufacturing process, they can easily move away from these pre-designed traces due to their elastic properties.

[0004] In some application scenarios, the total length of the cable assembly can reach hundreds of meters, which is very different from the traditional FPC application scenario, which only requires 25 to 30 inches (or at most 1 meter).

[0005] To this end, the present invention provides a manufacturing process for a high-speed hybrid optical flexible cable. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention provides a manufacturing process of a high-speed hybrid optical flexible cable.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: A manufacturing process for a high-speed hybrid optical flexible cable comprises the following process steps: etching a fiber channel pattern on a bare copper or aluminum area of ​​at least one of the top flexible printed circuit board and the bottom flexible printed circuit board; The top flexible printed circuit board and the bottom flexible printed circuit board move synchronously and wrap the synchronously moving optical fiber therein, and the optical fiber is fixed in the optical fiber channel pattern by prepreg; The top flexible printed circuit board and the bottom flexible printed circuit board are press-connected by a lamination process.

[0008] Further, when the number of the top flexible printed circuit boards and the bottom flexible printed circuit boards is not less than two, the butt connection of the two top flexible printed circuit boards or the two bottom flexible printed circuit boards comprises the following steps: Opening mechanical guide pin holes on the alignment area of ​​the top flexible printed circuit board or the bottom flexible printed circuit board, wherein the two mechanical guide pin holes are used for rough alignment by mechanical guide pins; providing alignment marks on the alignment area of ​​the top flexible printed circuit board or the bottom flexible printed circuit board for precise optical computer camera vision alignment; When the two top flexible printed circuit boards or the two bottom flexible printed circuit boards are precisely aligned, the two top flexible printed circuit boards or the two bottom flexible printed circuit boards are connected together through conductive pads and a mechanical clamp.

[0009] Furthermore, the alignment mark is a sawtooth pattern.

[0010] Furthermore, the number of the top flexible printed circuit boards is the same as the number of the bottom flexible printed circuit boards.

[0011] Furthermore, when the optical fiber is in the optical fiber channel pattern, the following processing steps are also included: applying prepreg on the optical fiber and / or the optical fiber channel pattern; The prepreg is then smoothed and dried using a scraper.

[0012] Furthermore, the prepreg is epoxy resin or polyimide prepreg.

[0013] Furthermore, the top flexible printed circuit board and the bottom flexible printed circuit board are made of polyimide or PTE flexible printed circuit material, and the surface of the polyimide or PTE flexible printed circuit material has copper foil or aluminum foil.

[0014] Furthermore, before the optical fiber enters the optical fiber channel pattern, a pre-set optical fiber wiring guide head is used to accurately enter the optical fiber channel pattern.

[0015] The above technical solution of the present invention has the following beneficial technical effects: The present invention fixes the optical fiber by using an optical fiber channel pattern and a fixing tool, and designs a special seam pattern to connect two flexible printed circuit boards, thereby being able to manufacture a high-speed hybrid optical flexible cable with a length of hundreds of meters, which is suitable for use in a variety of application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the wiring of optical fibers in a high-speed hybrid optical flexible cable proposed by the present invention; Figure 2 A cross-sectional schematic diagram of a high-speed hybrid optical flexible cable proposed by the present invention; Figure 3A schematic diagram of a manufacturing process of a high-speed hybrid optical flexible cable proposed by the present invention; Figure 4 for Figure 3 Schematic diagram of the use of the fixing tool; Figure 5 A schematic diagram of the alignment and connection of two top flexible printed circuit boards; Figure 6 A schematic diagram of a sawtooth pattern.

[0017] Numbers in the figure: 1, top flexible printed circuit board; 2, bottom flexible printed circuit board; 3, optical fiber; 4, prepreg; 5, optical fiber channel pattern; 6, copper foil or aluminum foil; 7, optical fiber wiring guide head; 8, fixing tool; 801, distribution needle; 802, scraper; 803, heating element; 9, mechanical guide pin hole; 10, alignment mark; 1001, sawtooth pattern; 11, conductive pad; DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0019] like Figure 1-Figure 6 As shown, the present invention provides a manufacturing process for a high-speed hybrid optical flexible cable, comprising the following process steps: A fiber channel pattern 5 is etched on the bare copper or aluminum area of ​​at least one of the top flexible printed circuit board 1 and the bottom flexible printed circuit board 2, such as Figure 1 As shown, the wiring of the optical fiber 3 is usually irregular in shape, and the shape of the flexible printed circuit board is also irregular. The channel spacing is etched by photolithography to match the optical fiber diameter size. For a bare optical fiber with only a cladding, the size is about 125um, and for an optical fiber with an external coating material, the diameter is about 250um; The top flexible printed circuit board 1 and the bottom flexible printed circuit board 2 move synchronously and wrap the synchronously moving optical fiber 3 inside. The optical fiber 3 is fixed in the optical fiber channel pattern 5 by the prepreg 4 and the fixing tool 8; the fixing tool 8 includes a distribution needle 801, a scraper 802 and a heating element 803. The prepreg 4 is injected through the distribution needle 801, then evenly scraped by the scraper 802, and finally cured by the heating element 803; the prepreg 4 can firmly bond the top flexible printed circuit board 1 and the bottom flexible printed circuit board 2, and at the same time fill any gap between the top flexible printed circuit board 1 and the bottom flexible printed circuit board 2.

[0020] The top flexible printed circuit board 1 and the bottom flexible printed circuit board 2 are press-connected by a lamination process.

[0021] In a specific embodiment of the present invention, a special seam pattern is designed to ensure accurate alignment between panels. When the number of the top flexible printed circuit board 1 and the bottom flexible printed circuit board 2 is not less than two, the two top flexible printed circuit boards 1 or the bottom flexible printed circuit boards 2 are butted together, including the following steps: A mechanical guide pin hole 9 is provided on the alignment area of ​​the top flexible printed circuit board 1 or the bottom flexible printed circuit board 2, and the two mechanical guide pin holes 9 are used for rough alignment through mechanical guide pins; Providing alignment marks 10 on the alignment area of ​​the top flexible printed circuit board 1 or the bottom flexible printed circuit board 2 for precise optical computer camera vision alignment; When the two top flexible printed circuit boards 1 or the two bottom flexible printed circuit boards 2 are precisely aligned, the two top flexible printed circuit boards 1 or the two bottom flexible printed circuit boards 2 are connected together through the conductive pads 11 and the mechanical clamps, thereby realizing the precise manufacturing of high-speed hybrid optical flexible cables with a length of several hundred meters.

[0022] In a specific embodiment of the present invention, the alignment mark 10 is a sawtooth pattern 1001 .

[0023] In a specific embodiment of the present invention, the number of the top flexible printed circuit boards 1 and the number of the bottom flexible printed circuit boards 2 are the same.

[0024] In a specific embodiment of the present invention, when the optical fiber 3 is in the channel pattern of the optical fiber 3, the following processing steps are also included: Applying prepreg 4 on the optical fiber 3 and / or the optical fiber channel pattern 5; The prepreg 4 is successively scraped and dried by a scraper 802 .

[0025] In a specific embodiment of the present invention, the prepreg 4 uses epoxy or polyimide prepreg, and the fiber guide tip pulls the optical fiber out of the fiber spool and guides each optical fiber to the target channel etched on the flexible printed circuit board. Epoxy glue is then dispensed onto the fiber guide channel. The scraper is followed by epoxy dispensing to smooth the epoxy and make the epoxy glue flat before lamination. There is a heating element behind the scraper that can immediately cure the epoxy to ensure that the optical fiber is properly fixed. The temperature and heating time of the heating element are properly controlled to ensure that the epoxy is just hardened. The entire cable assembly then goes through a lamination process before cutting its final shape.

[0026] In a specific embodiment of the present invention, the top flexible printed circuit board 1 and the bottom flexible printed circuit board 2 are made of polyimide or PTE flexible printed circuit material, and the surface of the polyimide or PTE flexible printed circuit material has copper foil or aluminum foil 6 .

[0027] In a specific embodiment of the present invention, before the optical fiber 3 enters the optical fiber channel pattern 5, a pre-set optical fiber wiring guide head 7 is used to accurately enter the optical fiber channel pattern 5.

[0028] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A manufacturing process for a high-speed hybrid optical flexible cable, characterized in that: The process steps include: etching a fiber channel pattern on a bare copper or aluminum area of ​​at least one of the top flexible printed circuit board and the bottom flexible printed circuit board; The top flexible printed circuit board and the bottom flexible printed circuit board move synchronously and wrap the synchronously moving optical fiber therein, and the optical fiber is fixed in the optical fiber channel pattern by prepreg; The top flexible printed circuit board and the bottom flexible printed circuit board are press-connected by a lamination process.

2. The manufacturing process of a high-speed hybrid optical flexible cable according to claim 1, characterized in that: When the number of the top flexible printed circuit boards and the bottom flexible printed circuit boards is not less than two, the two top flexible printed circuit boards or the bottom flexible printed circuit boards are butted together, comprising the following steps: Opening mechanical guide pin holes on the alignment area of ​​the top flexible printed circuit board or the bottom flexible printed circuit board, wherein the two mechanical guide pin holes are used for rough alignment by mechanical guide pins; providing alignment marks on the alignment area of ​​the top flexible printed circuit board or the bottom flexible printed circuit board for precise optical computer camera vision alignment; When the two top flexible printed circuit boards or the two bottom flexible printed circuit boards are precisely aligned, the two top flexible printed circuit boards or the two bottom flexible printed circuit boards are connected together through conductive pads and a mechanical clamp.

3. The manufacturing process of a high-speed hybrid optical flexible cable according to claim 2, characterized in that: The alignment mark is a sawtooth pattern.

4. The manufacturing process of a high-speed hybrid optical flexible cable according to claim 1, characterized in that: The number of the top flexible printed circuit boards is the same as the number of the bottom flexible printed circuit boards.

5. The manufacturing process of a high-speed hybrid optical flexible cable according to claim 1, characterized in that: When the optical fiber is within the optical fiber channel pattern, the process further includes the following steps: applying prepreg on the optical fiber and / or the optical fiber channel pattern; The prepreg is then smoothed and dried using a scraper.

6. The manufacturing process of a high-speed hybrid optical flexible cable according to claim 5, characterized in that: The prepreg is epoxy resin or polyimide prepreg.

7. The manufacturing process of a high-speed hybrid optical flexible cable according to claim 1, characterized in that: The top flexible printed circuit board and the bottom flexible printed circuit board are made of polyimide or PTE flexible printed circuit material, and the surface of the polyimide or PTE flexible printed circuit material has copper foil or aluminum foil.

8. The manufacturing process of a high-speed hybrid optical flexible cable according to claim 1, characterized in that: Before the optical fiber enters the optical fiber channel pattern, a pre-set optical fiber wiring guide head is used to accurately enter the optical fiber channel pattern.

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