Processing method for preventing residual glue in flexible area of rigid-flexible combined board

Abstract

The invention discloses a processing method for preventing glue from remaining in a flexible area of a rigid-flex board, relates to the technical field of rigid-flex board production processes, and can prevent resin from flowing into the flexible area at a through groove position and improve the product yield. The processing method comprises the following steps of lamination, primary copper reduction, primary drilling, primary adhesive tape pasting, primary copper deposition, primary external light imaging, secondary adhesive tape pasting, resin hole plugging, baking after resistance welding, primary ceramic plate grinding, secondary copper reduction, secondary ceramic plate grinding, tertiary adhesive tape pasting, secondary drilling, secondary copper deposition and secondary external light imaging. Before the primary copper deposition step, the resin hole plugging step and the secondary drilling step, adhesive is pasted at the through groove position of the flexible area, the flexible area is protected, resin and other substrate scraps are prevented from falling into the flexible area, the flexible area can be protected in an all-around mode, the resin is prevented from flowing into the flexible area at the through groove position, and the product yield is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of rigid-flexible board production technology, and in particular to a processing method for preventing glue from remaining in a flexible area of ​​a rigid-flexible board. Background Art

[0002] At present, during the production and processing of the rigid-flexible combination board with through-slot design, because the flexible area at the through-slot position is exposed, there will often be resin residue at the through-slot position during the resin plugging production process, and it is not easy to clean. If it is not cleaned in time, after baking and curing in the subsequent process, resin residue will be left in the flexible area at the through-slot position, resulting in product scrapping. Summary of the invention

[0003] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art, and to provide a processing method for preventing glue from remaining in the flexible area of ​​a rigid-flexible board, which can prevent the resin from flowing into the flexible area at the through groove position and improve the product yield.

[0004] The present invention provides a processing method for preventing glue from remaining in the flexible area of ​​a rigid-flexible board, comprising the following steps:

[0005] Lamination: Stacking and laminating several core boards into a motherboard;

[0006] Initial copper reduction: reduce the surface copper thickness of the motherboard;

[0007] Initial drilling: Drill holes that need to be filled with resin in the rigid area according to design requirements;

[0008] Initial tape application: Apply tape to the through-slot position of the flexible area;

[0009] Initial copper plating: a layer of copper is plated on the inner wall of the hole that needs to be filled with resin;

[0010] Initial external light imaging: a layer of dry film is applied to the rigid area to protect the circuit in the rigid area;

[0011] Secondary tape application: Apply tape to the through-slot position of the flexible area;

[0012] Resin plugging: Fill the resin into the holes that need to be filled with resin;

[0013] Post-solder mask baking: bake and solidify the resin;

[0014] Initial ceramic grinding: grinding the rigid areas, cleaning the resin and protruding resin on the board surface;

[0015] Secondary copper reduction: reduce the surface copper thickness of the motherboard again;

[0016] Secondary ceramic grinding plate: grinding the copper surface in the rigid area to make it smooth.

[0017] Apply tape three times: Apply tape again to the slots in the flexible area;

[0018] Secondary drilling: drilling holes for components and / or electrical connections in rigid areas;

[0019] Secondary copper plating: a layer of copper is plated on the inner wall of the component hole and / or electrical connection hole;

[0020] Secondary external light imaging: Produce graphics on the copper surface of rigid areas.

[0021] A processing method for preventing glue from remaining in the flexible area of ​​a rigid-flexible board according to an embodiment of the present invention has at least the following beneficial effects: glue is applied to the through-slot position of the flexible area before the initial copper plating step, the resin plugging step, and the secondary drilling step to protect the flexible area and prevent resin and other substrate debris from falling into the flexible area. The flexible area can be fully protected, and the resin is prevented from flowing into the flexible area at the through-slot position, thereby greatly improving the product yield.

[0022] According to a processing method for preventing glue from remaining in the flexible area of ​​a rigid-flexible board described in the present invention, when the thickness of the rigid layer cover is ≥0.25 mm, a white high-temperature tape is used in the initial glue application and the third tape application steps.

[0023] According to the processing method for preventing glue from remaining in the flexible area of ​​a rigid-flexible board described in the present invention, the white high-temperature tape used in the initial glue sticking and the third tape sticking steps is made by laser, and the tape size is 0.05mm smaller than the single side of the flexible area of ​​the through groove.

[0024] According to a processing method for preventing adhesive from being left in the flexible area of ​​a rigid-flexible board described in the present invention, PI high-temperature tape is used in the secondary tape application step.

[0025] According to a processing method for preventing glue from remaining in the flexible area of ​​a rigid-flexible board described in the present invention, the PI high-temperature tape used in the secondary tape pasting step is made by laser, and the size of the PI high-temperature tape is 0.05 mm smaller than the single side of the flexible area of ​​the through groove.

[0026] According to a processing method for preventing adhesive from remaining in the flexible area of ​​a rigid-flexible board described in the present invention, in the first external light imaging step and the second external light imaging step, the white high-temperature tape at the through-slot position is torn off between the etching and film stripping steps.

[0027] According to a processing method for preventing glue from remaining in the flexible area of ​​a rigid-flexible board described in the present invention, when the thickness of the rigid layer cover is less than 0.25 mm, PI high-temperature tape is used in the initial tape step, the secondary tape step and the tertiary tape step.

[0028] According to a processing method for preventing glue from remaining in the flexible area of ​​a rigid-flexible board described in the present invention, the PI high-temperature tape used in the initial taping step, the secondary taping step and the tertiary taping step is made by laser, and the size of the PI high-temperature tape is 0.05 mm smaller than the single side of the flexible area of ​​the through groove.

[0029] According to a processing method for preventing adhesive from remaining in the flexible area of ​​a rigid-flexible board described in the present invention, in the first external light imaging step and the second external light imaging step, the PI high-temperature tape at the through-slot position is torn off between the etching and film stripping steps.

[0030] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention is further described below in conjunction with the accompanying drawings and embodiments;

[0032] Figure 1 The process flow chart of the preferred embodiment of the present invention. DETAILED DESCRIPTION

[0033] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0034] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0035] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0036] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0037] Reference Figure 1 A processing method for preventing glue from remaining in the flexible area of ​​a rigid-flexible board comprises the following steps:

[0038] Lamination: Stacking and laminating several core boards into a motherboard;

[0039] Initial copper reduction: reduce the surface copper thickness of the motherboard;

[0040] Initial drilling: Drill holes that need to be filled with resin in the rigid area according to design requirements;

[0041] Initial tape application: Apply tape to the through-slot position of the flexible area;

[0042] Initial copper plating: a layer of copper is plated on the inner wall of the hole that needs to be filled with resin;

[0043] Initial external light imaging: a layer of dry film is applied to the rigid area to protect the circuit in the rigid area;

[0044] Secondary tape application: Apply tape to the through-slot position of the flexible area;

[0045] Resin plugging: Fill the resin into the holes that need to be filled with resin;

[0046] Post-solder mask baking: bake and solidify the resin;

[0047] Initial ceramic grinding: grinding the rigid areas, cleaning the resin and protruding resin on the board surface;

[0048] Secondary copper reduction: reduce the surface copper thickness of the motherboard again;

[0049] Secondary ceramic grinding plate: grinding the copper surface in the rigid area to make it smooth.

[0050] Apply tape three times: Apply tape again to the slots in the flexible area;

[0051] Secondary drilling: drilling holes for components and / or electrical connections in rigid areas;

[0052] Secondary copper plating: a layer of copper is plated on the inner wall of the component hole and / or electrical connection hole;

[0053] Secondary external light imaging: Produce graphics on the copper surface of rigid areas.

[0054] It can be understood that before the initial copper plating step, the resin plugging step, and the secondary drilling step, glue is applied to the through-slot position of the flexible area to protect the flexible area and prevent resin and other substrate debris from falling into the flexible area. The flexible area can be fully protected, and the resin is prevented from flowing into the flexible area at the through-slot position, which greatly improves the product yield.

[0055] In the first embodiment of the present invention, the thickness of the rigid layer cover is ≥0.25 mm. When the thickness of the rigid layer cover is ≥0.25 mm, a white high temperature tape is used in the first adhesive application and the third adhesive tape application steps.

[0056] It is understandable that by attaching the white high temperature tape to the slot position of the flexible area, a physical isolation effect is achieved to prevent the resin from entering the flexible area. This step effectively avoids the problem of resin residue, reduces the quality problems caused by resin penetration, ensures the smooth progress of the entire process, and thus improves the qualified rate of the product.

[0057] Furthermore, in the first embodiment of the present invention, the white high temperature tape used in the first and third tape application steps is made by laser, and the size of the tape is 0.05 mm smaller than the single side of the through slot flexible zone.

[0058] Furthermore, in the first embodiment of the present invention, in the secondary tape application step, PI high temperature tape is used.

[0059] Furthermore, in the first embodiment of the present invention, the PI high temperature tape used in the secondary tape application step is made by laser, and the size of the PI high temperature tape is 0.05 mm smaller than the single side of the through slot flexible zone.

[0060] Furthermore, in the first embodiment of the present invention, in the first external light imaging step and the second external light imaging step, the white high temperature tape at the through groove position is torn off between the etching and film stripping steps.

[0061] In the second embodiment of the present invention, the thickness of the rigid layer cover is less than 0.25 mm. When the thickness of the rigid layer cover is less than 0.25 mm, PI high temperature tape is used in the first tape application step, the second tape application step, and the third tape application step.

[0062] Furthermore, in the second embodiment of the present invention, the PI high temperature tape used in the first taping step, the second taping step and the third taping step is made by laser, and the size of the PI high temperature tape is 0.05 mm smaller than the single side of the through slot flexible zone.

[0063] It is worth noting that by attaching the PI high temperature tape to the slot position of the flexible area, a physical isolation effect is achieved to prevent the resin from entering the flexible area. This step effectively avoids the problem of resin residue, reduces the quality problems caused by resin penetration, ensures the smooth progress of the entire process, and thus improves the product qualification rate.

[0064] Furthermore, in the second embodiment of the present invention, in the first external light imaging step and the second external light imaging step, the PI high temperature tape at the through groove position is torn off between the etching and film stripping steps.

[0065] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A processing method for preventing glue from remaining in the flexible area of ​​a rigid-flexible board, characterized in that: The following steps are involved: Lamination: Stacking and laminating several core boards into a motherboard; Initial copper reduction: reduce the surface copper thickness of the motherboard; Initial drilling: Drill holes that need to be filled with resin in the rigid area according to design requirements; Initial tape application: Apply tape to the through-slot position of the flexible area; Initial copper plating: a layer of copper is plated on the inner wall of the hole that needs to be filled with resin; Initial external light imaging: a layer of dry film is applied to the rigid area to protect the circuit in the rigid area; Secondary tape application: Apply tape to the through-slot position of the flexible area; Resin plugging: Fill the resin into the holes that need to be filled with resin; Post-solder mask baking: bake and solidify the resin; Initial ceramic grinding: grinding the rigid areas, cleaning the resin and protruding resin on the board surface; Secondary copper reduction: reduce the surface copper thickness of the motherboard again; Secondary ceramic grinding plate: grinding the copper surface in the rigid area to make it smooth. Apply tape three times: Apply tape again to the slots in the flexible area; Secondary drilling: drilling holes for components and / or electrical connections in rigid areas; Secondary copper plating: a layer of copper is plated on the inner wall of the component hole and / or electrical connection hole; Secondary external light imaging: Produce graphics on the copper surface of rigid areas.

2. A processing method for preventing glue from remaining in the flexible area of ​​a rigid-flexible board according to claim 1, characterized in that: When the rigid layer cover thickness is ≥ 0.25 mm, use white high temperature tape in the primary and tertiary taping steps.

3. A processing method for preventing glue from remaining in the flexible area of ​​a rigid-flexible board according to claim 2, characterized in that: The white high temperature tape used in the first and third taping steps is made by laser, and the tape size is 0.05 mm smaller than the single side of the through slot flexible area.

4. A processing method for preventing glue from remaining in the flexible area of ​​a rigid-flexible board according to claim 2, characterized in that: In the secondary taping step, PI high temperature tape is used.

5. A processing method for preventing glue from remaining in the flexible area of ​​a rigid-flexible board according to claim 4, characterized in that: The PI high temperature tape used in the secondary tape application step is made by laser, and the size of the PI high temperature tape is 0.05 mm smaller than the single side of the through slot flexible area.

6. According to a processing method for preventing adhesive from being left in the flexible area of ​​a rigid-flexible board as described in claim 2, in the first external light imaging step and the second external light imaging step, the white high-temperature tape at the through-slot position is torn off between the etching and film stripping steps.

7. A processing method for preventing glue from remaining in the flexible area of ​​a rigid-flexible board according to claim 1, characterized in that: When the rigid layer cover thickness is less than 0.25 mm, PI high temperature tape is used in the primary tape step, the secondary tape step, and the tertiary tape step.

8. A processing method for preventing glue from remaining in the flexible area of ​​a rigid-flexible board according to claim 7, characterized in that: The PI high temperature tape used in the first taping step, the second taping step and the third taping step is made by laser, and the size of the PI high temperature tape is 0.05mm smaller than the single side of the flexible area of ​​the through groove.

9. A processing method for preventing glue from remaining in the flexible area of ​​a rigid-flexible board according to claim 7, characterized in that: In the first external light imaging step and the second external light imaging step, the PI high temperature tape at the through groove position is torn off between the etching and film stripping steps.

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