A method for manufacturing a high-frequency communication circuit board with a stepped structure

Abstract

The application discloses a high-frequency communication circuit board manufacturing method with a step structure, wherein the range inside the forming line is an effective area, and other areas are invalid areas, and the method comprises the following steps: taking a first high-frequency material copper-clad plate, manufacturing a first window, taking a high-frequency material prepreg, manufacturing a second window, forming a window prepreg, taking a second high-frequency material copper-clad plate, manufacturing an auxiliary circuit pattern along the forming line to the invalid area, taking a single-sided copper-clad plate, manufacturing a blue glue layer, cutting according to the position and size corresponding to the first window, aligning and stacking the aforementioned layers in sequence from top to bottom, vacuum pressing after pre-pressing, milling and processing the forming line, and forming a high-frequency communication circuit board; the method sets a pressing pad and a blue glue layer, provides adhesion of the pressing pad and an auxiliary accurate positioning medium, manufactures an auxiliary pattern, provides a "pad adhesion" buffer effect for a milling cutter and high-frequency material, prevents milling burrs and wire drawing, improves pressing accuracy after vacuum pressing after pre-pressing, and prevents deviation.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of circuit board processing, in particular to a high-frequency communication circuit board manufacturing method with a stepped structure. BACKGROUND

[0002] For antenna circuit boards, signal transceiver circuit boards and other special circuit boards applied in the fields of low-altitude aircraft, ground base stations, portable high-frequency communication equipment, etc., high-frequency characteristic materials with low dielectric loss are required to be used for preparation; for some cases where specific plugging, welding or different signal layer differentiation is required to form a signal transmission process, high-frequency communication circuit boards with stepped structure design appear.

[0003] Compared with ordinary epoxy resin glass fiber materials, high-frequency materials have stronger resistance and inertia, so the difficulty of processing to form circuit boards is greater, and there is a stepped structure, which further increases the processing difficulty.

[0004] At present, for high-frequency communication circuit boards with a stepped structure, the main processing difficulty lies in the formation of the stepped structure and the forming processing of the overall circuit board; for the processing of the stepped structure, the window of the corresponding layer of the stepped surface is first made, and then it is pressed to form the stepped structure; for the forming processing, the ordinary milling method is used to complete it.

[0005] Since the pressing processing of high-frequency materials requires more pressure, higher temperature and longer time than ordinary materials, the window position will deform and overflow during pressing, affecting the precision and quality of the stepped position; and direct milling forming is prone to burr, wire drawing and other problems due to the strong inertia and toughness of high-frequency materials.

[0006] Based on the above background and problems, it is necessary to provide a high-frequency communication circuit board manufacturing method with a stepped structure. SUMMARY

[0007] The present application provides a high-frequency communication circuit board manufacturing method with a stepped structure to solve the problems of deformation, overflow, burr, wire drawing and other problems in the existing high-frequency communication circuit board with a stepped structure during processing. The processing material of the high-frequency communication circuit board is designed with a forming line, the range within the forming line is an effective area, and other areas are invalid areas; the manufacturing method comprises the following steps:

[0008] S10: taking a first high-frequency material copper-clad plate, making a circuit pattern, and making a first window to form a windowed core plate; taking a high-frequency material prepreg, making a second window, the size of the second window matching the first window to form a windowed prepreg; taking a second high-frequency material copper-clad plate, making a circuit pattern, and making an auxiliary circuit pattern along the forming line to the ineffective area to form a bottom core plate; taking a single-sided copper-clad plate, making a blue glue layer on the surface thereof to form a glue-containing layer copper-clad plate, and cutting the glue-containing layer copper-clad plate according to the position and size corresponding to the first window to form a pressing pad plate;

[0009] S20: sequentially aligning and stacking the windowed core plate, the windowed prepreg, and the bottom core plate from top to bottom, the auxiliary circuit pattern facing the windowed prepreg, and the first window and the second window being stacked to form a windowed blind slot; placing the pressing pad plate in the windowed blind slot to form a stacked structure; pre-pressing the stacked structure, and then vacuum pressing to form a pressed plate;

[0010] S30: milling and processing the pressed plate according to the forming line, then removing the remaining pressing pad plate, and cleaning to form the high-frequency communication circuit board.

[0011] Optionally, the single-sided copper-clad plate is an FR-4 copper-clad plate or a high-frequency material copper-clad plate.

[0012] Optionally, the high-frequency material is a PTFE material, a ceramic powder composite epoxy resin material, or a PI material.

[0013] Optionally, the forming of the bottom core plate further includes making a through hole in the range of the auxiliary circuit pattern to form an exhaust hole.

[0014] Optionally, the forming of the glue-containing layer copper-clad plate is making the blue glue layer on the copper layer surface of the single-sided copper-clad plate according to the position corresponding to the first window to form the glue-containing layer copper-clad plate.

[0015] Optionally, the pre-pressing is making a pre-pressing mold, the pre-pressing mold being made with a groove, the area of the groove covering the exhaust hole.

[0016] Optionally, the forming of the stacked structure is setting a glue layer to the edge area between the windowed core plate and the windowed prepreg, and the edge area between the windowed prepreg and the bottom core plate.

[0017] Optionally, the material of the glue layer is epoxy resin glue or acrylic glue.

[0018] Optionally, the forming line milling processing is that one side of the pressed pad of the pressed plate is the feed surface of the milling cutter, and the other side is the through surface; sulfur-free paper and high-density wood fiberboard are arranged in sequence from near to far toward the feed surface, and sulfur-free paper, phenolic resin board and high-density wood fiberboard are arranged in sequence from near to far toward the through surface; a milling stacking structure is formed, and the milling stacking structure is milled according to the forming line.

[0019] Optionally, the forming of the high-frequency communication circuit board further includes, after removing the remaining pressed pad, forming the stepped structure, using laser ablation along the concave corners of the stepped structure, and cleaning to form the high-frequency communication circuit board.

[0020] The technical solution of the present invention is to set a pressing pad, and the pressing pad is provided with a blue glue layer to provide adhesion of the pad and assist in precise positioning of the medium. The pressing pad is provided with a copper layer to provide anti-overflow glue at the stepped position and make the pressing pad have better dimensional stability, and make auxiliary graphics to provide a buffering effect of a "pad" layer for the contact between the milling cutter and the high-frequency material during subsequent milling and cutting processing, thereby preventing milling burrs and wiredrawing. The pressing is performed by vacuum pressing after pre-pressing to improve the positioning accuracy of the pressing and prevent problems such as pressing offset. Further, an exhaust hole is provided to effectively improve the adhesion of the blue glue layer, prevent gas from being hidden in the window blind groove, and improve processing reliability. Further, a pre-pressing mold is provided to provide an exhaust channel matching the exhaust hole to prevent the problem of gas hiding in the window blind groove caused by gas blockage due to poor discharge of blue glue from the exhaust hole. Further, a forming milling pad structure is provided to help prevent problems such as burrs and wiredrawing when the milling cutter is in direct contact with the high-frequency material. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0022] Figure 1 The main process flow chart of the embodiment of the present invention is included;

[0023] Figure 2 Schematic diagram of the cross section of the stacked structure of this embodiment;

[0024] Figure 3 for Figure 2 Schematic diagram of the planar structure of the AA surface;

[0025] Figure 4 is a schematic cross-sectional view of the pre-pressing structure of this embodiment;

[0026] Figure 5 Fig. 2 is a cross-sectional view of a laminated board according to the embodiment of the present application;

[0027] Figure 6 Fig. 3 is a schematic view of a milling and cutting process according to the embodiment of the present application;

[0028] Figure 7 Fig. 4 is a cross-sectional view of a high-frequency communication circuit board according to the embodiment of the present application;

[0029] Figure 8 Fig. 5 is a plan view of a high-frequency communication circuit board according to the embodiment of the present application;

[0030] Figure 9 Fig. 6 is a partial view of a high-frequency communication circuit board according to the embodiment of the present application.

[0031] BRIEF DESCRIPTION OF THE DRAWINGS

[0032]

[0033] The object, features and advantages of the present application will be further understood based on the embodiments described below, with reference to the drawings. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be apparently and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without any creative effort fall within the scope of the present application.

[0035] It should be noted that all the directionality indications (such as up, down, left, right, front, back, inside, outside, etc.) in the embodiments of the present application are only used to explain the relative position relationship, movement condition, etc. between the components in a certain posture (as shown in the drawings), and if the certain posture changes, the directionality indications also change accordingly.

[0036] In addition, the description such as “first”, “second” and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined with “first”, “second” can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of “plurality” is at least two, such as two, three, etc., unless otherwise specifically limited.

[0037] In addition, the technical solutions among various embodiments of the present application can be combined with each other, but the combination of the technical solutions should be considered not to exist and not within the protection scope of the present application when the combination of the technical solutions cannot be realized by the ordinary skilled in the art.

[0038] Please refer to Figure 1 ; Figure 1 The main process flow of the embodiment of the present application.

[0039] The manufacturing method of the high-frequency communication circuit board with a stepped structure of the embodiment of the present application comprises Figure 1 The main manufacturing process flow is described in detail in the following steps.

[0040] Please refer to Figure 2 and Figure 3 ; Figure 2 The cross-sectional schematic diagram of the stacked structure of the present embodiment; Figure 3 The plane structure schematic diagram of A-A of Figure 2 .

[0041] Step S10:

[0042] The manufacturing method of the high-frequency communication circuit board with a stepped structure of the present embodiment is designed with a forming line 10A in the processing data, and the range within the forming line 10A is an effective area, and other areas are invalid areas.

[0043] The manufacturing method comprises the following steps:

[0044] Step S10:

[0045] Take a first high-frequency material copper-clad plate, manufacture a circuit pattern, including a first circuit pattern layer 120, a first dielectric layer 130 and a second circuit pattern layer 140, and manufacture a first window 110 to form a window core plate 100.

[0046] Take a high-frequency material prepreg, manufacture a second window 210, and the size of the second window 210 matches the first window 110 to form a window prepreg 200.

[0047] Take a second high-frequency material copper-clad plate, manufacture a circuit pattern, including a third circuit pattern layer 320, a second dielectric layer 330, a fourth circuit pattern layer 340, and manufacture an auxiliary circuit pattern 310 along the forming line to the invalid area to form a bottom layer core plate 300.

[0048] Take a single-sided copper-clad plate, manufacture a blue glue layer 430 on the surface to form a glue-containing layer copper-clad plate, cut the glue-containing layer copper-clad plate according to the position and size corresponding to the first window, and manufacture a pressing pad plate 400, Figure 2The intermediate press-fit gasket 400 is composed of a buffer layer 410 , a copper layer 420 , and a blue glue layer 430 .

[0049] The first window 110 and the second window 210 are formed to provide a structural basis for the subsequent formation of a stepped structure; the auxiliary circuit pattern 310 is formed to provide a "pad" effect for the contact between the milling cutter and the second dielectric layer during milling and forming processing, thereby constraining the material cutting properties of the second dielectric layer 330 and avoiding the problems of flashing and drawing.

[0050] Optionally, the second window 210 is 20 μm to 50 μm smaller than the first window 110 on one side, so as to provide a space margin for glue flow when the windowed prepreg 200 is pressed.

[0051] Optionally, the width of the auxiliary circuit pattern 310 extending into the inactive area is 50 μm to 5.0 mm. The width is selected based on available space, and is preferably 2.0 mm, so that sufficient space can be reserved for forming the exhaust hole 350 .

[0052] In this embodiment, the high-frequency material is PTFE material, ceramic powder composite epoxy resin material or PI material.

[0053] In one embodiment, the forming of the copper clad laminate containing the adhesive layer is to form the copper clad laminate containing the adhesive layer by forming the blue adhesive layer 430 on the copper layer surface of the single-sided copper clad laminate at positions corresponding to the first openings 110 .

[0054] The blue glue layer 430 can be processed by silk screen printing. When silk screen printing, it can be made only in the area where the blue glue layer 430 is needed. On the one hand, it can save materials. On the other hand, it can prevent the problem of the blue glue layer 430 adhering to other tools or materials caused by silk screen printing first and then processing.

[0055] After the blue glue layer 430 is screen-printed, the blue glue layer is baked at 120° C. for 10 to 20 minutes to be cured.

[0056] See also Figure 4 and Figure 5 ; Figure 4 is a schematic cross-sectional view of the pre-pressing structure of this embodiment; Figure 5 Schematic diagram of the cross-sectional structure of the pressed plate of this embodiment.

[0057] Step S20:

[0058] The windowed core board 100, the windowed prepreg 200, the bottom core board 300 are sequentially aligned from top to bottom, the auxiliary circuit pattern 310 faces the windowed prepreg 200, the first window 110 and the second window 210 are aligned to form a windowed blind slot (not shown in the figure); the pressing pad 400 is attached in the windowed blind slot to form a stacking structure 10; the stacking structure is pre-pressed by using a pre-pressing structure 20, and then vacuum-pressed to form a pressed board 30.

[0059] The pressing pad 400 is used to form the attachment of the windowed blind slot, the copper layer of the pressing pad 400 prevents overflow of the corner position of the windowed blind slot during the pressing process, and forms a binding effect on the buffer material to prevent deformation of the material from causing deformation of the windowed blind slot during pressing. The blue glue layer 430 adheres to the pressing pad 400 during pressing to form accurate positioning and fixation of the pressing pad 400, and fills the remaining gap during pressing to further prevent deformation of the windowed blind slot during pressing. The blue glue layer 430 can be easily peeled off after subsequent milling and forming processing to form an auxiliary effect in the processing process.

[0060] Preferably, the thickness of the blue glue layer 430 is 10-50 μm, preferably 25 μm.

[0061] In the embodiment, the single-sided copper-clad plate is an FR-4 copper-clad plate or a high-frequency material copper-clad plate.

[0062] That is, the buffer layer 410 can be an FR-4 material or a high-frequency material to form a pressing pad 400 that has a strong matching with the base material of the circuit board itself, and to form a better covering type during the pressing process.

[0063] In the embodiment, the forming of the bottom core board 300 further includes making a through hole in the range of the auxiliary circuit pattern 310 to form an exhaust hole 350.

[0064] Making the exhaust hole 350 can effectively exhaust the gas in the windowed blind slot during the pressing process, and make the blue glue layer 430 form a further fixed state through the exhaust hole 350 to increase the fixation firmness of the pressing pad 400; preferably, the hole diameter of the exhaust hole 350 is 0.2 mm to prevent the problem of excessive overflow of the blue glue due to too large hole.

[0065] In the embodiment, the pre-pressing is to make a pre-pressing mold 500, the pre-pressing mold is provided with a groove 5110, and the area of the groove 5110 covers the exhaust hole 350.

[0066] The groove 5110 can further form a pre-pressing process in which the gas is exhausted from the windowed blind slot through the exhaust hole 350 into the groove 5110 to prevent the gas from being exhausted in time.

[0067] The pre-pressing is a way of using lower temperature, smaller pressure and shorter time to form the initial overall structure of the stacked structure 10 in the structural form, and to form the initial filling state of the press pad 400 and the windowed blind groove, and to preliminarily bond the blue glue layer 430, so that the gas in the windowed blind groove is first discharged, and the problems such as slippage, gas storage and offset of the press pad 400 caused by direct pressing are prevented. Preferably, the pre-pressing can use a temperature of 110°C to 150°C, a pressure of 13 kg / cm2 to 20 kg / cm2, and a pre-pressing time of 5 minutes to 15 minutes.

[0068] In the embodiment, the stacked structure 10 is formed by arranging the adhesive layer 600 on the edge area between the windowed core board 100 and the windowed prepreg 200, and on the edge area between the windowed prepreg 200 and the bottom core board 300.

[0069] In the embodiment, the material of the adhesive layer 600 is epoxy resin glue or acrylic glue.

[0070] The adhesive layer 600 can effectively bond the edges of the boards during the pre-pressing, further form the initial overall structure, and prevent slippage during the pressing of each layer. Preferably, the thickness of the adhesive layer 600 is 10 μm to 50 μm.

[0071] Please refer to Figure 6 , Figure 7 , Figure 8 and Figure 9 ; Figure 6 is a schematic diagram of the milling forming process of the embodiment; Figure 7 is a schematic diagram of the cross-sectional structure of the high-frequency communication circuit board of the embodiment; Figure 8 is a schematic diagram of the planar structure of the high-frequency communication circuit board of the embodiment, Figure 9 is a partial view of the high-frequency communication circuit board of the embodiment.

[0072] Step S30:

[0073] The press board 30 is milled according to the forming line, and then the remaining press pad 400 is removed, and the high-frequency communication circuit board 50 is formed after cleaning.

[0074] In the embodiment, the milling forming process is that one side of the press pad 400 of the press board 30 is the approach surface of the milling cutter 700, and the other side is the through surface; the sulfur-free paper 810 and the high-density wood fiber board 820 are arranged on the approach surface from near to far; the sulfur-free paper 810, the phenolic resin board 830 and the high-density wood fiber board 820 are arranged on the through surface from near to far; the milling stacked structure 40 is formed, and the milling stacked structure is milled according to the forming line.

[0075] The upper surface of the high-density wood fiber plate 820 can prevent the milling cutter 700 from directly contacting the high-frequency material and causing milling burrs and burrs. The high-density wood fiber plate 820 has a high density and provides effective pressure covering and milling buffer protection. The lower surface of the high-density wood fiber plate 820 and the phenolic resin plate 830 can improve the machining precision of the milling cutter 700 and facilitate chip removal, thereby preventing the formation of burrs and wire drawing problems.

[0076] Optionally, the thickness of the high-density wood fiber plate 820 is 1.0 mm to 4.0 mm, and the thickness of the phenolic resin plate 830 is 1.0 mm to 4.0 mm.

[0077] In the embodiment, the forming the high-frequency communication circuit board 50 further includes, after removing the remaining pressure pad 400, forming the stepped structure 900, using laser ablation along the recessed corner of the stepped structure, and cleaning to form the high-frequency communication circuit board 50.

[0078] To prevent the recessed corner of the windowed blind slot from overflowing during pressure bonding, laser ablation is used to remove excess overflow, improving the quality of the stepped structure.

[0079] It is worth noting that due to the precision of the circuit board in actual design and processing, the actual structure diagram and the thickness of each layer, the line width, and other dimensions are in microns, for example, the thickness of each layer is generally 5 μm to 50 μm. If the drawings in the specification are made according to the actual scale, there will be a problem of unclear illustration. Therefore, in order to more clearly represent the implementation process of the manufacturing method, the drawings of the embodiment are enlarged schematic diagrams of the technical features, and do not represent the size of the actual structure diagram, nor do they represent an enlarged view of the actual structure diagram.

[0080] The above is only a preferred embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation made based on the content of the specification and drawings, or direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. A manufacturing method of a high-frequency communication circuit board with a stepped structure, the high-frequency communication circuit board having a forming line designed in a processing data of the high-frequency communication circuit board, a range within the forming line being an effective area, and other areas being invalid areas; characterized in that The manufacturing method comprises the following steps: S10: taking a first high-frequency material copper-clad plate, manufacturing a circuit pattern, and manufacturing a first window to form a window core plate; taking a high-frequency material prepreg, manufacturing a second window, the size of the second window matching the first window to form a window prepreg; taking a second high-frequency material copper-clad plate, manufacturing a circuit pattern, and manufacturing an auxiliary circuit pattern to the invalid area along the forming line to form a bottom layer core plate; The bottom layer core plate further comprises manufacturing a through hole to the auxiliary circuit pattern range to form an exhaust hole; taking a single-sided copper-clad plate, manufacturing a blue glue layer on the surface to form a glue layer copper-clad plate, and cutting the glue layer copper-clad plate according to the position and size corresponding to the first window to manufacture a pressing pad plate; S20: aligning and stacking the window core plate, the window prepreg, and the bottom layer core plate from top to bottom in sequence, the auxiliary circuit pattern facing the window prepreg, the first window and the second window stacking to form a window blind slot; the pressing pad plate is attached to the window blind slot to form a stacking structure; pre-pressing the stacking structure, and then vacuum pressing to form a pressed plate; S30: milling and processing the pressed plate according to the forming line, then removing the remaining pressing pad plate, and cleaning to form the high-frequency communication circuit board.

2. The method for manufacturing a high-frequency communication circuit board with a stepped structure according to claim 1, wherein: The single-sided copper-clad plate is an FR-4 copper-clad plate or a high-frequency material copper-clad plate.

3. A method for manufacturing a high-frequency communication circuit board with a stepped structure according to claim 1 or 2, characterized in that: The high-frequency material is PTFE material, ceramic powder composite epoxy resin material, or PI material.

4. The method for manufacturing a high-frequency communication circuit board with a stepped structure according to claim 1, wherein: The glue layer copper-clad plate is manufactured by manufacturing the blue glue layer on the copper layer surface of the single-sided copper-clad plate according to the position corresponding to the first window to form the glue layer copper-clad plate.

5. The method for manufacturing a high-frequency communication circuit board with a stepped structure according to claim 1, wherein: The pre-pressing is manufacturing a pre-pressing mold, the pre-pressing mold is manufactured with a groove, the area of the groove covers the exhaust hole.

6. The method for manufacturing a high-frequency communication circuit board with a stepped structure according to claim 1, wherein: The stacking structure is formed by setting an adhesive layer to the edge area between the window core plate and the window prepreg, and the edge area between the window prepreg and the bottom layer core plate.

7. The method for manufacturing a high-frequency communication circuit board with a stepped structure according to claim 6, wherein: The material of the adhesive layer is epoxy resin glue or acrylic glue.

8. The method for manufacturing a high-frequency communication circuit board with a stepped structure according to claim 1, wherein: The forming line milling processing is that one side of the pressing pad plate of the pressed plate is the feed surface of the milling cutter, and the other side is the through surface; sulfur-free paper, high-density wood fiber board are sequentially arranged from near to far to the feed surface, and sulfur-free paper, phenolic resin board, high-density wood fiber board are sequentially arranged from near to far to the through surface; forming a milling and stacking structure, and milling and processing the milling and stacking structure according to the forming line.

9. A method for manufacturing a high-frequency communication circuit board with a stepped structure according to claim 1 or 8, characterized in that: The high-frequency communication circuit board further comprises forming the stepped structure after removing the remaining pressing pad plate, using laser ablation along the recessed corner of the stepped structure, and cleaning to form the high-frequency communication circuit board.

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