Circuit board pressing process

Abstract

The invention relates to the technical field of circuit board manufacturing, and particularly discloses a circuit board pressing process, which comprises the following steps of: stacking a newly-added circuit layer on a basic circuit layer, and overlapping a semi-cured adhesive layer between the newly-added circuit layer and the basic circuit layer; the newly-added circuit layer and the basic circuit layer are bonded together through thermocompression bonding to form a multi-layer circuit layer; if the multiple circuit layers are warped, blind fishing is carried out on the multiple circuit layers to form stress grooves so as to release pressing thermal stress, and then the next process is carried out; and if the multiple circuit layers do not warp, performing the next process. According to the invention, if the multiple circuit layers are warped after lamination, the multiple circuit layers are subjected to blind fishing to form the stress grooves so as to release the lamination thermal stress, so that the warpage degree is reduced, and the process can prevent the multiple circuit layers from being warped and recovered after being subjected to external force; therefore, the influence on the subsequent process due to the high warping degree of the multi-layer circuit board is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of circuit board manufacturing, and in particular to a circuit board pressing process. Background Art

[0002] With the continuous development of electronic communication technology, electronic devices have more and more functions, resulting in a denser layout of circuit board devices and a continuous increase in the number of layers, which has led to an increase in the number of laminations during production. The circuit board lamination process plays an important role in the manufacture of electronic devices. It combines heat and pressure to fuse multiple layers of materials into a multi-layer structure, providing a solid foundation for the precise layout and functional realization of electronic components.

[0003] At present, for circuit boards with asymmetrical designs, that is, the semi-cured adhesive layers on both sides of the circuit layer are of different types, the circuit boards are prone to warping during the manufacturing process, and circuit boards with high warping degrees will affect the post-process operations. In the prior art, the way to solve the warping of circuit boards is mostly to straighten them by pressing, but this technology has little effect on circuit boards with severe warping, and the circuit boards are easily restored after being warped by external forces. Summary of the invention

[0004] The purpose of the present invention is to provide a circuit board pressing process to solve the problem that the circuit board in the prior art is mostly straightened by pressing, but this technology has little effect on circuit boards with severe warping, and the circuit board is easily restored after being warped by external force.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a circuit board pressing process, comprising the following steps:

[0007] Stacking the newly added circuit layer on the basic circuit layer, and stacking a semi-cured adhesive layer between the newly added circuit layer and the basic circuit layer;

[0008] The newly added circuit layer and the basic circuit layer are bonded together by thermal pressing to form a multi-layer circuit layer;

[0009] If the multi-layer circuit layer is warped, the multi-layer circuit layer is blindly fished to form a stress groove to release the thermal stress of the pressing, and then the next process is performed; if the multi-layer circuit layer is not warped, the next process is performed.

[0010] As an optional solution to the above-mentioned circuit board lamination process, the blind tapping of the multi-layer circuit layer to form the stress groove includes: blind tapping the back side of the multi-layer circuit layer where warping occurs to form the stress groove.

[0011] As an optional solution of the above-mentioned circuit board lamination process, the stress groove includes a first stress groove extending along the length direction of the multi-layer circuit layer and / or a second stress groove extending along the width direction of the multi-layer circuit layer.

[0012] As an optional scheme for the above-mentioned circuit board lamination process, a plurality of the first stress grooves and / or the second stress grooves are provided, and a plurality of the first stress grooves are arranged at intervals along the width direction of the multi-layer circuit layer and / or a plurality of the second stress grooves are arranged at intervals along the length direction of the multi-layer circuit layer.

[0013] As an optional solution of the above-mentioned circuit board pressing process, the stress groove depth is the thickness of the newly added circuit layer.

[0014] As an optional solution of the above-mentioned circuit board lamination process, after blindly tapping the multi-layer circuit layer to form a stress groove and before carrying out the next process, it also includes: opening a first drainage hole at the end of the stress groove.

[0015] As an optional solution of the above-mentioned circuit board pressing process, after blindly tapping the multi-layer circuit layer to form the stress groove and before carrying out the next process, it also includes: opening a second drainage hole in the middle position of the stress groove.

[0016] As an optional solution for the above-mentioned circuit board pressing process, a plurality of the first drainage holes and a plurality of the second drainage holes are provided, and a plurality of the first drainage holes are densely arranged at the ends of the stress groove, and a plurality of the second drainage holes are densely arranged in the middle position of the stress groove.

[0017] As an optional solution of the above-mentioned circuit board lamination process, before stacking the newly added circuit layer on the basic circuit layer, it also includes: surface treatment of the surfaces of the newly added circuit layer and the basic circuit layer.

[0018] As an optional solution of the above-mentioned circuit board lamination process, after the newly added circuit layer and the basic circuit layer are bonded together by heat lamination to form a multi-layer circuit layer, it also includes: performing thickness control processing on the multi-layer circuit layer.

[0019] The beneficial effects of the present invention are:

[0020] In the manufacturing process of the circuit board, the semi-cured adhesive layer and the newly added circuit layer are stacked on the basic circuit layer in sequence, and the resin of the semi-cured adhesive layer is melted, flowed, gelled and finally hardened through hot pressing, so as to achieve the bonding of the newly added circuit layer to the basic circuit layer. If the circuit board is an asymmetrical design, the multi-layer circuit layer will warp after pressing. At this time, the multi-layer circuit layer is blindly fished to form a stress groove to release the pressing thermal stress, thereby reducing the degree of warping. This process can prevent the multi-layer circuit layer from recovering from warping after being subjected to external force, thereby avoiding the high warping of the multi-layer circuit board and affecting the subsequent process, so that the circuit board that warps in the manufacturing process can continue to be produced, thereby improving the product yield and facilitating the production of high-difficulty circuit boards. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the process flow of a circuit board pressing process provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. 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, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and the first feature "above", "above" and "above" the second feature include the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature "below", "below" and "below" the second feature include the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0024] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0026] like Figure 1 As shown, this embodiment provides a circuit board pressing process, including the following steps:

[0027] Stacking the newly added circuit layer on the basic circuit layer, and stacking a semi-cured adhesive layer between the newly added circuit layer and the basic circuit layer;

[0028] The newly added circuit layer and the basic circuit layer are bonded together by thermal pressing to form a multi-layer circuit layer;

[0029] If the multi-layer circuit layer is warped, the multi-layer circuit layer is blindly fished to form a stress groove to release the pressing thermal stress, and then the next process is carried out; if the multi-layer circuit layer is not warped, the next process is carried out.

[0030] The circuit board pressing process provided in the present embodiment is that in the manufacturing process of the circuit board, the semi-cured adhesive layer and the newly added circuit layer are stacked in sequence on the basic circuit layer, and the resin of the semi-cured adhesive layer is melted, flowed, gelled and finally hardened by heat pressing, so as to achieve the bonding of the newly added circuit layer to the basic circuit layer. If the circuit board is an asymmetric design, the multi-layer circuit layer will be warped after pressing. At this time, the multi-layer circuit layer is blindly fished to form a stress groove to release the pressing thermal stress, thereby achieving a reduction in the degree of warping. This process can prevent the multi-layer circuit layer from recovering from warping after being subjected to external force, and avoids the high warping degree of the multi-layer circuit layer affecting the subsequent process, so that the circuit board that is warped in the manufacturing process can be produced continuously, thereby improving the product yield and facilitating the production of high-difficulty circuit boards.

[0031] Furthermore, before stacking the new circuit layer on the base circuit layer, the surface of the new circuit layer and the base circuit layer is treated to prevent pollutants attached to the surfaces of the new circuit layer and the base circuit layer from affecting the lamination of the new circuit layer on the base circuit layer. Optionally, the surface treatment includes cleaning treatment and chemical treatment.

[0032] Furthermore, after the newly added circuit layer and the base circuit layer are bonded together by heat pressing to form a multi-layer circuit layer, the multi-layer circuit layer is subjected to thickness control processing so that the laminated multi-layer circuit layer meets the actual thickness requirement. Optionally, the thickness control processing includes grinding processing.

[0033] Furthermore, the multi-layer circuit layer is blindly tapped to form a stress groove, including blind tapping on the back side of the multi-layer circuit layer where the warping occurs to form a stress groove, so as to release the thermal stress of the press bonding from the back side of the multi-layer circuit layer where the warping occurs, thereby reducing the warping degree. The depth of the stress groove is the thickness of the newly added circuit layer, so as to prevent the internal structure of the multi-layer circuit layer from being affected by the groove being too deep, and the warping degree cannot be effectively reduced by the groove being too shallow.

[0034] Specifically, the stress grooves include a first stress groove extending along the length direction of the multi-layer circuit layer and / or a second stress groove extending along the width direction of the multi-layer circuit layer, so that the stress grooves are less difficult to open, and the grooves can be opened in one direction or multiple directions to meet actual needs. Among them, there are a plurality of first stress grooves and / or second stress grooves, and a plurality of first stress grooves are arranged at intervals along the width direction of the multi-layer circuit layer and / or a plurality of second stress grooves are arranged at intervals along the length direction of the multi-layer circuit layer, so that the degree of warping can be improved by setting a plurality of first stress grooves and / or a plurality of second stress grooves, and at the same time, by arranging three types of stress grooves, that is, only the first stress groove is set, or only the second stress groove is set, or the first stress groove and the second stress groove are set at the same time, to correspond to the multi-layer circuit layers with different warping types.

[0035] Furthermore, after blindly fishing the multi-layer circuit layer to form the stress groove, before the next process is carried out, a first drainage hole is provided at the end of the stress groove, so that the first drainage hole can prevent the stress groove from storing medicine in the subsequent process and affecting the production quality of the circuit board. At the same time, after blindly fishing the multi-layer circuit layer to form the stress groove, before the next process is carried out, a second drainage hole is provided in the middle of the stress groove, so that the medicine can be discharged from the middle of the stress groove through the opening of the second drainage hole, and the stress groove is prevented from being too long and causing the medicine to be unable to be completely drained from the first drainage hole at the end. Optionally, a plurality of first drainage holes and second drainage holes are provided, and the plurality of first drainage holes are densely arranged at the end of the stress groove, and the plurality of second drainage holes are densely arranged in the middle of the stress groove, so that the plurality of first drainage holes and the plurality of second drainage holes are provided, so that the discharge capacity and discharge efficiency of the medicine can be improved.

[0036] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A circuit board pressing process, characterized in that: The following steps are involved: Stacking the newly added circuit layer on the basic circuit layer, and stacking a semi-cured adhesive layer between the newly added circuit layer and the basic circuit layer; The newly added circuit layer and the basic circuit layer are bonded together by thermal pressing to form a multi-layer circuit layer; If the multi-layer circuit layer is warped, the multi-layer circuit layer is blindly fished to form a stress groove to release the thermal stress of the pressing, and then the next process is performed; if the multi-layer circuit layer is not warped, the next process is performed.

2. The circuit board pressing process according to claim 1, characterized in that: The step of blindly tapping the multi-layer circuit layer to form the stress groove comprises: blindly tapping the back side of the multi-layer circuit layer where the warping occurs to form the stress groove.

3. The circuit board pressing process according to claim 1, characterized in that: The stress grooves include a first stress groove extending along the length direction of the multi-layer circuit layer and / or a second stress groove extending along the width direction of the multi-layer circuit layer.

4. The circuit board pressing process according to claim 3, characterized in that: A plurality of the first stress grooves and / or the second stress grooves are provided, and the plurality of the first stress grooves are arranged at intervals along the width direction of the multi-layer circuit layer and / or the plurality of the second stress grooves are arranged at intervals along the length direction of the multi-layer circuit layer.

5. The circuit board pressing process according to claim 1, characterized in that: The stress groove depth is the thickness of the newly added circuit layer.

6. The circuit board pressing process according to claim 1, characterized in that: After blindly fishing the multi-layer circuit layer to form the stress groove, before the next process is performed, the method further includes: opening a first drainage hole at the end of the stress groove.

7. The circuit board pressing process according to claim 6, characterized in that: After blindly fishing the multi-layer circuit layer to form the stress groove, before the next process is performed, the method further includes: opening a second drainage hole in the middle position of the stress groove.

8. The circuit board pressing process according to claim 7, characterized in that: A plurality of the first drainage holes and a plurality of the second drainage holes are provided, wherein the plurality of the first drainage holes are densely arranged at the ends of the stress groove, and the plurality of the second drainage holes are densely arranged at the middle position of the stress groove.

9. The circuit board pressing process according to any one of claims 1 to 8, characterized in that: Before stacking the newly added circuit layer on the basic circuit layer, the method further includes: performing surface treatment on the surfaces of the newly added circuit layer and the basic circuit layer.

10. The circuit board pressing process according to any one of claims 1 to 8, characterized in that: After the newly added circuit layer and the basic circuit layer are bonded together by thermal pressing to form a multi-layer circuit layer, the method further includes: performing thickness control processing on the multi-layer circuit layer.

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