Combined pre-fixing process of LCP-FPC multi-layer pre-fixed board

Abstract

The present invention discloses and provides a combined pre-fixing process for an LCP-FPC multilayer pre-fixed board, which can effectively solve the problem of poor pre-fixing bonding force after the LCP-FPC multilayer board is combined, so that the production can proceed smoothly. The LCP-FPC multilayer pre-fixed board includes a single-sided board and a double-sided board; the single-sided board includes a top copper foil and a first LCP dielectric layer, and the top copper foil is arranged on the first LCP dielectric layer; the double-sided board includes an inner circuit layer, a second LCP dielectric layer and a bottom copper foil, and the inner circuit layer and the bottom copper foil are respectively located above and below the second LCP dielectric layer; the first LCP dielectric layer is attached to the inner circuit layer, and a plurality of copper foil hollowing areas are provided on the waste edge of the inner circuit layer. The present invention is applied to the technical field of combined pre-fixing of LCP-FPC multilayer boards.

Description

Technical Field

[0001] The present invention relates to a LCP-FPC multilayer board combined pre-fixing technology, and in particular to a LCP-FPC multilayer pre-fixing board combined pre-fixing process. Background Art

[0002] The FPC multi-layer board combination requires that more than two FPC single-sided boards or double-sided boards be combined together through adhesive film, and pre-fixed by hot-stamping with an electric soldering iron so that the layers are bonded together to prevent misalignment between the layers before pressure is transmitted.

[0003] Conventional FPC multilayer boards use FCCL copper-clad laminate substrate + ordinary acrylic or epoxy resin film as interlayer adhesive. The film has good affinity with the substrate dielectric layer and copper foil. Conventional soldering iron hot-spotting method can achieve a certain bonding strength for pre-fixation. When LCP substrate is used to make FPC multilayer boards, the interlayer bonding depends on the LCP resin of the LCP substrate itself. The melting temperature of LCP resin is above 300°C, and the melt viscosity is very low. It is difficult to bond when using an ordinary flat-head soldering iron for pre-fixation, resulting in loose fixation and easy interlayer dislocation. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a combined pre-fixing process for LCP-FPC multi-layer pre-fixed boards, which can effectively solve the problem of poor bonding strength of the pre-fixing after hot-stamping of the LCP-FPC multi-layer boards, so that production can proceed smoothly.

[0005] The technical solution adopted by the present invention is:

[0006] The LCP-FPC multilayer pre-consolidated board includes a single-sided board F1 and a double-sided board F2; the single-sided board F1 includes a top copper foil A1 and a first LCP dielectric layer B1, and the top copper foil A1 is arranged on the first LCP dielectric layer B1; the double-sided board F2 includes an inner circuit layer A2, a second LCP dielectric layer B2 and a bottom copper foil A3, and the inner circuit layer A2 and the bottom copper foil A3 are respectively located on the upper side and the lower side of the second LCP dielectric layer B2; the first LCP dielectric layer B1 is attached to the upper side of the inner circuit layer A2; the combined pre-fixing process of the LCP-FPC multilayer pre-consolidated board includes the following steps:

[0007] a. A plurality of copper hollowing areas C are provided on the waste side of the inner circuit layer A2;

[0008] b. Use a high-temperature pointed soldering iron E to perform spot heat treatment on the top copper foil A1. The spot heat treatment position on the top copper foil A1 is located above the copper foil hollowed-out area C. The bottom of the first LCP dielectric layer B1 passes through the copper foil hollowed-out area C and then fuses with the top of the second LCP dielectric layer B2 to produce a fusion area D.

[0009] Furthermore, the hot point of the high temperature pointed soldering iron E is 350°C to 400°C.

[0010] Furthermore, the copper foil hollowed-out area C is manufactured by etching copper foil.

[0011] The beneficial effect of the present invention is that since a plurality of copper hollowing areas C are provided on the waste edge of the inner circuit layer A2, the lower side of the first LCP dielectric layer B1 passes through the copper hollowing area C and fuses with the upper side of the second LCP dielectric layer B2 to produce a fusion area D, which can effectively solve the problem of poor bonding strength of the pre-fixing after hot-stamping of the LCP-FPC multilayer board after assembly, so that production can proceed smoothly. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the structure when the single-sided board F1 and the double-sided board F2 have not been pre-fixed;

[0013] Figure 2 It is single-sided F1 and double-sided F2;

[0014] Figure 3 is a schematic diagram of the structure after the first LCP dielectric layer B1 and the second LCP dielectric layer B2 are fused;

[0015] Figure 4 It is a schematic diagram of the structure of the inner circuit layer A2. DETAILED DESCRIPTION

[0016] like Figure 1 and Figure 2 As shown, in this embodiment, the LCP-FPC multilayer pre-consolidated board includes a single-sided board F1 and a double-sided board F2; the single-sided board F1 includes a top copper foil A1 and a first LCP dielectric layer B1, and the top copper foil A1 is arranged on the first LCP dielectric layer B1; the double-sided board F2 includes an inner circuit layer A2, a second LCP dielectric layer B2 and a bottom copper foil A3, and the inner circuit layer A2 and the bottom copper foil A3 are respectively located on the upper side and the lower side of the second LCP dielectric layer B2; the first LCP dielectric layer B1 is attached to the upper side of the inner circuit layer A2, and a plurality of copper foil hollowing areas C are provided on the waste edge of the inner circuit layer A2.

[0017] In this embodiment, the inner circuit layer A2 is square, and three copper hollowing areas C are provided on each side of the inner circuit layer A2. Figure 4 As shown, the positions numbered 1-8 are the positions where the copper foil of the inner circuit layer is hollowed out.

[0018] like Figure 3 As shown, in this embodiment, the bottom surface of the first LCP dielectric layer B1 passes through the copper foil hollowing area C and merges with the top surface of the second LCP dielectric layer B2.

[0019] In this embodiment, the LCP-FPC multilayer pre-fixed board in the combined pre-fixing process of the LCP-FPC multilayer pre-fixed board includes a single-sided board F1 and a double-sided board F2; the single-sided board F1 includes a top copper foil A1 and a first LCP dielectric layer B1, and the top copper foil A1 is arranged on the first LCP dielectric layer B1; the double-sided board F2 includes an inner circuit layer A2, a second LCP dielectric layer B2 and a bottom copper foil A3, and the inner circuit layer A2 and the bottom copper foil A3 are respectively located on the upper side and the lower side of the second LCP dielectric layer B2; the first LCP dielectric layer B1 is attached to the upper side of the inner circuit layer A2, and the combined pre-fixing process includes the following steps:

[0020] a. A plurality of copper hollowing areas C are provided on the waste side of the inner circuit layer A2;

[0021] b. Use a high-temperature pointed soldering iron E to perform spot heat treatment on the top copper foil A1. The spot heat treatment position on the top copper foil A1 is located above the copper foil hollowed-out area C. The bottom of the first LCP dielectric layer B1 passes through the copper foil hollowed-out area C and then fuses with the top of the second LCP dielectric layer B2 to produce a fusion area D.

[0022] Furthermore, the hot point of the high temperature pointed soldering iron E is 350°C to 400°C.

[0023] Furthermore, the copper foil hollowed-out area C is manufactured by etching copper foil.

[0024] In this embodiment, the copper foil hollowed-out area is etched at the same position around the edge of each layer of the LCP-FPC to expose the dielectric layer to reduce the thickness, and then a high-temperature pointed soldering iron is used to pierce the area. The LCP dielectric layer in the area where the soldering iron tip penetrates melts and concave under the action of high temperature and pressure, and each layer of material flows or deforms to wedge into the lower layer of material, thereby generating bonding force.

[0025] The invention is applied to the technical field of LCP-FPC multilayer board combination pre-fixation.

[0026] Although the embodiments of the present invention are described with practical solutions, they do not constitute limitations on the meaning of the present invention. For those skilled in the art, it is obvious to modify the implementation scheme and combine it with other solutions based on this description.

Claims

1. Combined pre-fixing process of LCP-FPC multi-layer pre-fixed board, characterized by: The LCP-FPC multilayer pre-fixed board comprises a single-sided board (F1) and a double-sided board (F2); the single-sided board (F1) comprises a top copper foil (A1) and a first LCP dielectric layer (B1), and the top copper foil (A1) is arranged on the first LCP dielectric layer (B1); the double-sided board (F2) comprises an inner circuit layer (A2), a second LCP dielectric layer (B2) and a bottom copper foil (A3), and the inner circuit layer (A2) and the bottom copper foil (A3) are respectively located on the upper side and the lower side of the second LCP dielectric layer (B2); the first LCP dielectric layer (B1) is attached to the upper side of the inner circuit layer (A2), and the combined pre-fixing process comprises the following steps: a. A plurality of copper hollowing areas (C) are provided on the waste side of the inner circuit layer (A2); b. Using a high-temperature pointed soldering iron (E) to perform hot spots on the top copper foil (A1), wherein the hot spots on the top copper foil (A1) are located above the copper foil hollowed-out area (C), and the bottom of the first LCP dielectric layer (B1) passes through the copper foil hollowed-out area (C) and fuses with the top of the second LCP dielectric layer (B2) to produce a fusion area (D).

2. The combined pre-fixing process of the LCP-FPC multi-layer pre-fixed board according to claim 1 is characterized in that: The high temperature pointed soldering iron (E) has a hot point temperature of 350°C to 400°C.

3. The combined pre-fixing process of the LCP-FPC multi-layer pre-fixed board according to claim 1, characterized in that: The copper foil hollowed-out area (C) is manufactured by etching copper foil.

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