Manufacturing method of high-frequency communication circuit board with step structure

Abstract

The invention discloses a manufacturing method of a high-frequency communication circuit board with a stepped structure, which is characterized in that a range within a forming line is an effective area, and other areas are ineffective areas, and 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 windowing prepreg, taking a second high-frequency material copper-clad plate, manufacturing an auxiliary circuit pattern to the ineffective area along the forming line, taking a single-sided copper-clad plate, manufacturing a blue glue layer, cutting according to the position and the size corresponding to the first window, sequentially aligning and stacking the plates from top to bottom, pre-pressing, then carrying out vacuum pressing, milling the forming line, and forming the high-frequency communication circuit board; by arranging the pressing base plate and the blue glue layer, adhesion of the pressing base plate and an auxiliary accurate positioning medium are provided, an auxiliary pattern is manufactured, the'padding 'buffering effect is provided for a milling cutter and a high-frequency material, milling burrs and wiredrawing are prevented, vacuum pressing is conducted after pre-pressing, the pressing precision is improved, and deviation is prevented.

Description

Technical Field

[0001] The invention relates to the field of circuit board processing, and in particular to a method for manufacturing a high-frequency communication circuit board with a stepped structure. Background Art

[0002] For special circuit boards such as antenna circuit boards and signal transceiver circuit boards used in low-altitude aircraft, ground base stations, portable high-frequency communication equipment and other fields, it is required to use high-frequency characteristic materials with low dielectric loss; for some situations that require specific plug-in, welding or different signal layers to form a signal transmission process, high-frequency communication circuit boards with a stepped structure design appear.

[0003] Compared with ordinary epoxy resin fiberglass materials, high-frequency materials have stronger tolerance and inertness, so it is more difficult to process them into circuit boards, and the presence of a stepped structure further increases the difficulty of processing.

[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 molding processing of the entire circuit board; for the processing of the stepped structure, it is generally adopted to first make a window opening of the corresponding layer of the stepped surface, and then press it together to form a stepped structure. For the molding processing, it is completed by ordinary milling cutting.

[0005] Since the pressing process of high-frequency materials requires greater pressure, higher temperature and longer time than that of ordinary materials, the window position will be deformed and glue overflow will occur during pressing, affecting the step position accuracy and quality; and direct milling forming is prone to flashing, 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 method for manufacturing a high-frequency communication circuit board with a stepped structure. Summary of the invention

[0007] The present invention aims at the problems of step position deformation, glue overflow, flashing and wire drawing during the processing of the high-frequency communication circuit board with a step structure in the prior art, and provides a method for manufacturing a high-frequency communication circuit board with a step structure. The processing data of the high-frequency communication circuit board is designed with a molding line, the range within the molding line is an effective area, and the other areas are invalid areas; the manufacturing method comprises the following steps: S10: Take a first high-frequency material copper-clad laminate, make a circuit pattern, and make a first window to form a window core board; take a high-frequency material prepreg, make a second window, the size of the second window matches the first window, and form a window prepreg; take a second high-frequency material copper-clad laminate, make a circuit pattern, and make an auxiliary circuit pattern along the molding line to the invalid area to form a bottom core board; take a single-sided copper-clad laminate, make a blue glue layer on its surface to form a copper-clad laminate containing a glue layer, cut the copper-clad laminate containing a glue layer according to the position and size corresponding to the first window, and make a pressed pad; S20: Aligning and stacking the window core board, the window prepreg, and the bottom core board from top to bottom, with the auxiliary circuit pattern facing the window prepreg, and the first window and the second window stacked to form a window blind groove; attaching the pressing pad to the window blind groove to form a stacked structure; pre-pressing the stacked structure, and then vacuum pressing to form a pressed board; S30: milling the pressed plate according to the forming line, then removing the remaining pressed pad, and cleaning it to form the high-frequency communication circuit board.

[0008] Optionally, the single-sided copper clad laminate is a FR-4 copper clad laminate, or a high-frequency material copper clad laminate.

[0009] Optionally, the high-frequency material is PTFE material, ceramic powder composite epoxy resin material or PI material.

[0010] Optionally, the forming of the bottom core board further includes making through holes within the auxiliary circuit pattern to form exhaust holes.

[0011] Optionally, the forming of the copper-clad laminate containing the glue layer is to form the copper-clad laminate containing the glue layer by making the blue glue layer on the surface of the copper layer of the single-sided copper-clad laminate according to the position corresponding to the first window.

[0012] Optionally, the pre-pressing is to manufacture a pre-pressing mold, wherein the pre-pressing mold is manufactured with a groove, and the area of ​​the groove covers the exhaust hole.

[0013] Optionally, the stacked structure is formed by providing an adhesive layer to the edge area between the window opening core board and the window opening prepreg, and to the edge area between the window opening prepreg and the bottom core board.

[0014] Optionally, the material of the adhesive layer is epoxy resin glue or acrylic glue.

[0015] Optionally, the forming line milling process 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.

[0016] 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.

[0017] 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, and the pressing pad is provided with a copper layer to provide anti-overflow glue at the stepped position and make the pressing pad have good dimensional stability, and make auxiliary graphics to provide a buffering effect of a "pad" layer when the milling cutter contacts with the high-frequency material during subsequent milling and cutting processing, so as to prevent milling burrs and wiredrawing, and to use vacuum pressing after pre-pressing to improve the positioning accuracy of the pressing and prevent problems such as pressing offset; further arranging an exhaust hole can effectively improve the adhesion and bonding force of the blue glue layer, prevent gas from being hidden in the window blind groove, and improve processing reliability; further arranging a pre-pressing mold to provide an exhaust channel matching the exhaust hole, so as 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 arranging a forming milling pad structure helps to 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

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

[0019] Figure 1 The main process flow chart of the embodiment of the present invention is included; Figure 2 is a schematic cross-sectional view of the stacked structure of this embodiment; Figure 3 for Figure 2 Schematic diagram of the plane structure of the AA surface; Figure 4 is a cross-sectional schematic diagram of the pre-pressing structure of this embodiment; Figure 5 is a schematic diagram of the cross-sectional structure of the pressed plate of this embodiment; Figure 6 Schematic diagram of milling and forming processing in this embodiment; Figure 7 is a schematic diagram of the cross-sectional structure of the high-frequency communication circuit board of this embodiment; Figure 8 Schematic diagram of the planar structure of the high-frequency communication circuit board of this embodiment; Fig. 9 This is a partial picture of the high-frequency communication circuit board of this embodiment.

[0020] Description of Figure Numbers:

[0021] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, inside, outside...) are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0024] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0025] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0026] See also Figure 1 ; Figure 1 The main process flow chart included in the embodiment of the present invention.

[0027] A method for manufacturing a high-frequency communication circuit board with a stepped structure according to an embodiment of the present invention comprises: Figure 1 The main production process is described in detail step by step as follows.

[0028] See also Figure 2 and Figure 3 ; Figure 2 is a schematic cross-sectional view of the stacked structure of this embodiment; Figure 3 for Figure 2 Schematic diagram of the planar structure of the AA surface.

[0029] Step S10: In the method for manufacturing a high-frequency communication circuit board with a stepped structure of this embodiment, a forming line 10A is designed in the processing data, and the range within the forming line 10A is a valid area, and the other areas are invalid areas.

[0030] The preparation method comprises the following steps: Step S10: A first high-frequency copper-clad laminate is used to make a circuit pattern, including a first circuit pattern layer 120 , a first dielectric layer 130 and a second circuit pattern layer 140 , and a first window 110 is made to form a window core board 100 .

[0031] A high-frequency material prepreg is used to make a second window 210 , the size of which matches the first window 110 , to form a window prepreg 200 .

[0032] Take the second high frequency material copper clad board, make circuit patterns, including the third circuit pattern 320, the second dielectric layer 330, and the fourth circuit pattern 340, and make the auxiliary circuit pattern 310 along the forming line to the invalid area to form the bottom core board 300.

[0033] Take a single-sided copper-clad laminate, make a blue glue layer 430 on its surface, form a copper-clad laminate containing a glue layer, cut the copper-clad laminate containing a glue layer according to the position and size corresponding to the first window opening, and make a pressing pad 400. Figure 2 The middle press-fit gasket 400 is composed of a buffer layer 410 , a copper layer 420 , and a blue glue layer 430 .

[0034] The first window 110 and the second window 210 are formed to provide a structural basis for the subsequent formation of a stepped structure; an 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 characteristics of the second dielectric layer 330 and avoiding the problems of burring and wire drawing.

[0035] Optionally, the size of the second window 210 is 20 μm to 50 μm smaller than that of the first window 110 on one side, so as to provide a space margin for glue flow when the window prepreg 200 is pressed.

[0036] Optionally, the width of the auxiliary circuit pattern 310 extending toward the ineffective area is 50 μm to 5.0 mm. The width is selected according to available space, and is preferably 2.0 mm, so that enough space can be reserved for making the exhaust hole 350 .

[0037] In this embodiment, the high-frequency material is PTFE material, ceramic powder composite epoxy resin material or PI material.

[0038] 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 making the blue adhesive layer 430 on the surface of the copper layer of the single-sided copper-clad laminate at a position corresponding to the first opening 110 .

[0039] The blue glue layer 430 can be processed by silk screen printing. When silk screen printing, it can be made only for the area where the blue glue layer 430 is needed. On the one hand, it can save materials, and 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 the blue glue layer 430 first and then processing it.

[0040] 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.

[0041] See also Figure 4 and Figure 5 ; Figure 4 is a cross-sectional schematic diagram of the pre-pressing structure of this embodiment; Figure 5 It is a schematic diagram of the cross-sectional structure of the pressed plate of this embodiment.

[0042] Step S20: The window core board 100, the window semi-cured sheet 200, and the bottom core board 300 are aligned and stacked in sequence from top to bottom, with the auxiliary circuit pattern 310 facing the window semi-cured sheet 200, and the first window 110 and the second window 210 are stacked to form a window blind groove (not shown in the figure); the pressing pad 400 is attached to the window blind groove to form a stacking structure 10; the stacking structure is pre-pressed using a pre-pressing structure 20, and then vacuum pressed to form a pressed board 30.

[0043] The lamination pad 400 is used to form a pad for the blind window groove. The copper layer of the lamination pad 400 is used to prevent glue overflow at the corner of the blind window groove during the lamination process, and to form a binding effect on the buffer layer material to prevent material deformation and cause deformation of the blind window groove during lamination. The blue glue layer 430 is used to adhere the lamination pad 400 during lamination to form precise positioning and fixation of the lamination pad 400, and to fill the remaining gap during lamination to further prevent deformation of the blind window groove during lamination. 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.

[0044] Preferably, the blue glue layer 430 has a thickness of 10 μm to 50 μm, preferably 25 μm.

[0045] In this embodiment, the single-sided copper clad laminate is a FR-4 copper clad laminate or a high-frequency material copper clad laminate.

[0046] That is, the buffer layer 410 can be made of FR-4 material or high-frequency material, forming a pressing pad 400 that has a strong match with the substrate of the circuit board itself, thereby forming a better conformation during the pressing process.

[0047] In this embodiment, the forming of the bottom core board 300 further includes making a through hole within the range of the auxiliary circuit pattern 310 to form a vent hole 350 .

[0048] The exhaust hole 350 can effectively exhaust the gas in the blind window groove during the pressing process, and the blue glue layer 430 can be further fixed through the exhaust hole 350, thereby increasing the fixing firmness of the pressing pad 400; preferably, the diameter of the exhaust hole 350 is 0.2 mm to prevent the hole from being too large and causing excessive overflow of the blue glue.

[0049] In this embodiment, the pre-pressing is to manufacture a pre-pressing mold 500 , wherein the pre-pressing mold is manufactured with a groove 5110 , and the area of ​​the groove 5110 covers the exhaust hole 350 .

[0050] The groove 5110 can be further provided to form a self-opening blind groove during the pre-pressing process so that the gas can be exhausted into the groove 5110 through the exhaust hole 350, thereby preventing the gas from not being exhausted in time.

[0051] Pre-pressing is a method of using lower temperature, smaller pressure and shorter time to form the stacked structure 10 into an initial overall structure in terms of structural morphology, and to form the initial filling state of the pressed pad 400 and the window blind groove, so that the blue glue layer 430 is initially bonded, and the gas in the window blind groove is first discharged to prevent problems such as slippage, gas storage, and displacement of the pressed pad 400 caused by direct pressing. Preferably, the pre-pressing can use a temperature of 110°C to 150°C and a pressure of 13kg / cm² to 20kg / cm² for 5 minutes to 15 minutes.

[0052] In this embodiment, the stacked structure 10 is formed by providing an adhesive layer 600 to the edge area between the window core board 100 and the window semi-cured sheet 200, and to the edge area between the window semi-cured sheet 200 and the bottom core board 300.

[0053] In this embodiment, the material of the adhesive layer 600 is epoxy resin glue or acrylic glue.

[0054] Providing the adhesive layer 600 can effectively combine the edges of the plates during the pre-pressing process, further forming an initial overall structure, and preventing the layers from slipping when pressed together; preferably, the thickness of the adhesive layer 600 is 10 μm to 50 μm.

[0055] See also Figure 6 , Figure 7 , Figure 8 and Fig. 9 ; Figure 6 Schematic diagram of milling and forming processing in this embodiment; Figure 7 is a schematic diagram of the cross-sectional structure of the high-frequency communication circuit board of this embodiment; Figure 8 is a schematic diagram of the planar structure of the high-frequency communication circuit board of this embodiment, Fig. 9 This is a partial picture of the high-frequency communication circuit board of this embodiment.

[0056] Step S30: The pressing plate 30 is milled along the forming line, and then the remaining pressing pad 400 is removed and cleaned to form the high-frequency communication circuit board 50 .

[0057] In this embodiment, the molding line milling processing is that one side of the pressing pad 400 of the pressing plate 30 is the feed surface of the milling cutter 700, and the other side is the through surface; sulfur-free paper 810 and high-density wood fiberboard 820 are arranged in sequence from near to far toward the feed surface, and sulfur-free paper 810, phenolic resin board 830, and high-density wood fiberboard 820 are arranged in sequence from near to far toward the through surface; a milling stacking structure 40 is formed, and the milling stacking structure is milled according to the molding line.

[0058] The high-density wood fiberboard 820 arranged on the upper surface can prevent the milling cutter 700 from directly contacting the high-frequency material to generate milling burrs and burrs. The high-density wood fiberboard 820 has a high density and provides effective compression and milling buffer protection. The high-density wood fiberboard 820 and the phenolic resin board 830 arranged on the lower surface also improve the milling processing accuracy of the milling cutter 700, and are beneficial to chip removal, preventing the formation of burrs and wire drawing problems.

[0059] Optionally, the thickness of the high-density wood fiber board 820 is 1.0 mm to 4.0 mm, and the thickness of the phenolic resin board 830 is 1.0 mm to 4.0 mm.

[0060] In this embodiment, the forming of the high-frequency communication circuit board 50 also includes, after removing the remaining pressing pad 400 , forming the stepped structure 900 , using laser ablation along the concave corners of the stepped structure, and cleaning to form the high-frequency communication circuit board 50 .

[0061] In order to prevent glue overflow at the concave corners of the blind window groove during pressing, laser ablation is used to remove excess glue and improve the quality of the stepped structure.

[0062] It is worth noting that due to the actual design and processing of circuit boards, the actual structure diagram and the thickness of each layer, line width and other dimensions are all in the micron level. For example, the thickness of each layer is generally 5μm to 50μm. If the drawings in the specification are made according to the actual proportion, there will be a problem of unclear drawings. Therefore, in order to more clearly show the implementation process of the manufacturing method, the drawings of this embodiment are all schematic diagrams that enlarge the technical features, which do not represent the size of the actual structure diagram, nor do they represent enlarged views of the actual structure diagram in proportion.

[0063] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A method for manufacturing a high-frequency communication circuit board with a stepped structure, wherein a forming line is designed in the processing data of the high-frequency communication circuit board, the range within the forming line is a valid area, and the other areas are invalid areas; It is characterized in that The production method comprises the following steps: S10: Take a first high-frequency material copper-clad board, make a circuit pattern, and make a first window to form a window core board; Take a high-frequency material prepreg and make a second window, the size of the second window matches the first window, to form a window prepreg; Take the second high-frequency material copper-clad board, make a circuit pattern, and make an auxiliary circuit pattern along the molding line toward the invalid area to form a bottom core board; Take a single-sided copper-clad laminate, make a blue glue layer on its surface to form a copper-clad laminate containing a glue layer, cut the copper-clad laminate containing a glue layer according to the position and size corresponding to the first window opening, and make a pressing pad; S20: Align and stack the window core board, the window prepreg, and the bottom core board from top to bottom, with the auxiliary circuit pattern facing the window prepreg, and the first window and the second window are stacked to form a window blind groove; and the pressing pad is attached to the window blind groove to form a stacked structure; Pre-pressing the stacked structure, and then vacuum pressing to form a pressed plate; S30: milling the pressed plate according to the forming line, then removing the remaining pressed pad, and cleaning it to form the high-frequency communication circuit board.

2. A method for manufacturing a high-frequency communication circuit board with a stepped structure as claimed in claim 1, characterized in that: The single-sided copper clad laminate is FR-4 copper clad laminate, or high-frequency material copper clad laminate.

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

4. A method for manufacturing a high-frequency communication circuit board with a stepped structure as claimed in claim 1, characterized in that: The forming of the bottom core board also includes making through holes within the auxiliary circuit pattern to form exhaust holes.

5. The method for manufacturing a high-frequency communication circuit board with a stepped structure as claimed in claim 1, characterized in that: The forming of the copper-clad laminate containing the adhesive layer is to make the blue adhesive layer on the surface of the copper layer of the single-sided copper-clad laminate according to the position corresponding to the first window to form the copper-clad laminate containing the adhesive layer.

6. A method for manufacturing a high-frequency communication circuit board with a stepped structure as claimed in claim 4, characterized in that: The pre-pressing is to make a pre-pressing mold, wherein the pre-pressing mold is made with a groove, and the area of ​​the groove covers the exhaust hole.

7. A method for manufacturing a high-frequency communication circuit board with a stepped structure as claimed in claim 1, characterized in that: The stacked structure is formed by providing an adhesive layer to the edge area between the window opening core board and the window opening prepreg, and the edge area between the window opening prepreg and the bottom core board.

8. A method for manufacturing a high-frequency communication circuit board with a stepped structure as claimed in claim 7, characterized in that: The material of the adhesive layer is epoxy resin glue or acrylic glue.

9. The method for manufacturing a high-frequency communication circuit board with a stepped structure as claimed in claim 1, characterized in that: The milling process of the molding line is that one side of the pressing pad of the pressing 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 sequentially arranged on the cutting surface from near to far, and sulfur-free paper, phenolic resin board and high-density wood fiberboard are sequentially arranged on the through surface from near to far; A milling stacking structure is formed, and the milling stacking structure is milled according to the forming line.

10. A method for manufacturing a high-frequency communication circuit board with a stepped structure as claimed in claim 1 or 9, characterized in that: The forming of the high-frequency communication circuit board also includes, after removing the remaining pressed pad, forming the stepped structure, using laser ablation along the concave corner of the stepped structure, and cleaning to form the high-frequency communication circuit board.

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