Inductive band, comb-shaped band-pass filter and preparation method of comb-shaped band-pass filter

Abstract

The invention discloses an inductive band, a comb-shaped band-pass filter and a preparation method of the comb-shaped band-pass filter, and belongs to the technical field of band-pass filters. The inductive tape comprises a first ceramic dielectric layer and an inductive circuit layer printed on one side of the first ceramic dielectric layer; the inductive circuit layer comprises at least one inductive structure; the inductor structure comprises at least two inductor branch lines arranged in parallel and first transition electrodes arranged perpendicular to the inductor branch lines. The first transition electrode is arranged on one side of each inductance branch line along the extension direction of the inductance branch line and is connected with each inductance branch line; the inductor structure is cut to serve as an inductor layer in the comb-shaped band-pass filter; the vertical projection of the cutting line corresponding to the inductance structure on the inductance structure is overlapped with the first transition electrode; the width of the first transition electrode in the extension direction of the inductance branch line is larger than or equal to the stroke error threshold value of cutting deviation of the cutting equipment. According to the embodiment of the invention, the influence of cutting deviation can be eliminated, so that the length of the inductor branch before and after cutting is unchanged.

Description

Technical Field

[0001] The present invention relates to the technical field of bandpass filters, and in particular to an inductive bandpass comb-shaped bandpass filter and a preparation method thereof. Background Art

[0002] With the rapid development of mobile communications, integration and modularization have become the development trend of the market. Comb bandpass filters are widely used in microwave frequency bands because of their compact structure. Comb bandpass filters are composed of multiple groups of parallel resonant units. In the resonant unit, a single inductor branch can be used as an inductor. Among them, the length of the inductor branch is a very sensitive parameter that affects the inductance value. Therefore, in the production process of the comb bandpass filter, the error control during cutting is particularly critical. However, at present, the cutting process level is poor and the error control is not ideal. In the production process of the comb bandpass filter, there is a deviation in the cutting of the inductor branch, which affects the inductance value in the resonant unit of the product, thereby causing frequency offset, resulting in electrical unqualified products. Summary of the invention

[0003] The present invention provides an inductor raw tape, a comb-shaped bandpass filter and a preparation method thereof, so as to eliminate the influence of cutting deviation, so that the length of the inductor branch line remains unchanged before and after cutting, thereby eliminating the frequency deviation caused by the difference in inductance value.

[0004] In a first aspect, an embodiment of the present invention provides an inductor green tape, comprising: a first ceramic dielectric layer and an inductor circuit layer printed on one side of the first ceramic dielectric layer; the inductor circuit layer comprises: at least one inductor structure;

[0005] The inductor structure comprises: at least two inductor branches arranged in parallel, and a first transition electrode arranged perpendicular to the inductor branches; the first transition electrode is arranged on one side of each of the inductor branches along the extension direction of the inductor branches, and connects each of the inductor branches;

[0006] Among them, the inductor structure is used as the inductor layer in the comb bandpass filter after cutting; the vertical projection of the cutting line corresponding to the inductor structure on the inductor structure overlaps with the first transition electrode; the width of the first transition electrode in the extension direction of the inductor branch line is greater than or equal to the stroke error threshold of the cutting deviation of the cutting equipment.

[0007] Optionally, the inductor circuit layer includes a plurality of the inductor structures;

[0008] Wherein, a plurality of the inductor structures are arranged in an array in the inductor circuit layer;

[0009] And / or, at least two adjacent inductor structures are mirror-symmetrical along the extension direction of the inductor branch line and share the same first transition electrode.

[0010] Optionally, the first transition electrode is an integrated structure, connecting all the inductor branches in the same inductor structure;

[0011] Alternatively, in the same inductor structure, the first transition electrode comprises: a plurality of sub-electrodes perpendicular to the inductor branches and arranged along the arrangement direction of the inductor branches; and one sub-electrode is connected to at least one of the inductor branches.

[0012] Optionally, the cutting line corresponding to the inductor structure includes a first side, a vertical projection of the first side on the inductor structure falls within the range of the first transition electrode; a distance between the vertical projection of the first side on the inductor structure and a side of the first transition electrode close to the inductor branch line is greater than or equal to the stroke error threshold;

[0013] And / or, the cutting line corresponding to the inductor structure includes a first side, a vertical projection of the first side on the inductor structure falls within the range of the first transition electrode; and a distance between the vertical projection of the first side on the inductor structure and a side of the first transition electrode away from the inductor branch line is greater than or equal to the stroke error threshold;

[0014] And / or, the range of the stroke error threshold is: 30-100um;

[0015] And / or, the width of the first transition electrode in the extension direction of the inductor branch line is in the range of 30-200 um.

[0016] Optionally, in the inductor structure, the inductor branches arranged in parallel constitute an inductor branch group; the inductor structure further comprises: two coupling taps, which are arranged on both sides of the inductor branch group along the arrangement direction of the inductor branches, and each coupling tap is connected to the inductor branch adjacent thereto;

[0017] Wherein, the vertical projection of the cutting line corresponding to the inductor structure on the inductor structure also overlaps with the two coupling taps respectively.

[0018] Optionally, the inductor circuit layer includes a plurality of the inductor structures; wherein at least two adjacent inductor structures are mirror-symmetrical along the arrangement direction of the inductor branches, and two adjacent coupling taps in the two mirror-symmetrical inductor structures are connected as one.

[0019] In a second aspect, an embodiment of the present invention provides a method for preparing a comb bandpass filter, comprising:

[0020] A filter substrate is provided; wherein the filter substrate comprises the inductor green tape provided by any embodiment of the present invention; and a cutting line corresponding to each of the inductor structures in the inductor green tape is provided on the surface of the filter substrate;

[0021] The filter substrate is cut along the cutting line to obtain comb-shaped bandpass filters.

[0022] Optionally, the inductor structure includes an inductor branch line, a first transition electrode and a coupling tap; the filter substrate is cut along the cutting line to obtain each filter monomer;

[0023] After obtaining each filter monomer, it also includes:

[0024] Sintering each of the filter monomers to form a sintered monomer;

[0025] A grounding electrode and a transmission electrode are prepared on the periphery of each of the sintered monomers to form each of the comb-shaped bandpass filters; wherein, in the comb-shaped bandpass filters, each of the inductance branches is connected to the grounding electrode through the first transition electrode retained after cutting, and the coupling tap retained after cutting is connected to the transmission electrode.

[0026] Optionally, the filter matrix further includes:

[0027] A first capacitor strip includes a first capacitor circuit layer; the first capacitor circuit layer includes a first capacitor structure corresponding to the inductor structure one by one; the first capacitor structure is cut to serve as a first capacitor layer in a comb-shaped bandpass filter, and the first capacitor layer is connected to the ground electrode;

[0028] A cross-coupling raw tape, comprising a cross-coupling circuit layer; the cross-coupling circuit layer comprises a cross-coupling structure corresponding to the inductance structure one by one; the cross-coupling structure is cut to serve as a cross-coupling layer in a comb-type bandpass filter, and the cross-coupling layer is connected to the ground electrode;

[0029] Wherein, in the filter substrate, the inductor strip, the first capacitor strip and the cross-coupling strip are stacked in sequence;

[0030] The filter substrate further includes: at least one of a first shielding raw tape and a second shielding raw tape;

[0031] The first shielding raw tape comprises a first shielding circuit layer, wherein the first shielding circuit layer comprises a first shielding structure corresponding to the inductance structure one by one; the first shielding structure is cut to serve as a first shielding layer in a comb-shaped bandpass filter, and the first shielding layer is connected to the ground electrode; the first shielding raw tape is arranged on a side of the inductance raw tape away from the first capacitance raw tape;

[0032] The second shielding raw tape includes a second shielding circuit layer, and the second shielding circuit layer includes a second shielding structure corresponding to the inductance structure one by one; the second shielding structure is used as the second shielding layer in the comb bandpass filter after cutting, and the second shielding layer is connected to the ground electrode; the second shielding raw tape is arranged on the side of the cross-coupling raw tape away from the first capacitor raw tape.

[0033] In a third aspect, an embodiment of the present invention further provides a comb-shaped bandpass filter, which is prepared using the preparation method of the comb-shaped bandpass filter provided by any embodiment of the present invention.

[0034] In the inductor raw tape provided by the embodiment of the present invention, by setting the first transition electrode in each inductor structure, the first transition electrode is set on the side of the inductor branch connected to the first transition electrode, the vertical projection of the cutting line corresponding to the inductor structure on the inductor structure overlaps with the first transition electrode, and the width of the first transition electrode in the extension direction of the inductor branch is set to be greater than or equal to the stroke error threshold of the cutting deviation of the cutting device, so that the cutting device can cut the first transition electrode in each inductor structure according to the cutting line during the cutting process. Even if the cutting device has a certain cutting deviation, the difference between the product obtained in the case of accurate alignment cutting is only the amount of the first transition electrode retained in the comb bandpass filter, and the cutting deviation no longer affects the length of each inductor branch. The length of the inductor branch along the extension direction of the inductor branch before and after cutting remains unchanged, and does not affect the effective electrical length of the inductor branch, which can eliminate the influence on the inductance value in each resonant unit in the product, thereby avoiding the resulting frequency offset and improving production consistency and product yield.

[0035] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. 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 these drawings without creative work.

[0037] Figure 1 It is a schematic diagram of the structure of an inductor belt provided by an embodiment of the present invention;

[0038] Figure 2 is a structural schematic diagram of an inductor structure provided by an embodiment of the present invention;

[0039] Figure 3 It is a structural schematic diagram of an inductor structure in the related art;

[0040] Figure 4 is a schematic structural diagram of another inductor strip provided by an embodiment of the present invention;

[0041] Figure 5 is a schematic structural diagram of another inductive strip provided by an embodiment of the present invention;

[0042] Figure 6 is a schematic structural diagram of another inductive strip provided by an embodiment of the present invention;

[0043] Figure 7 It is a schematic flow chart of a method for preparing a comb-shaped bandpass filter provided by an embodiment of the present invention;

[0044] Figure 8 is a schematic diagram of a three-dimensional structure of a comb-shaped bandpass filter provided by an embodiment of the present invention;

[0045] Fig. 9 is a schematic structural diagram of a first capacitor strip provided by an embodiment of the present invention;

[0046] Fig.10 is a schematic structural diagram of a cross-coupled ribbon provided by an embodiment of the present invention;

[0047] Fig.11 is a schematic diagram of the cross-sectional structure of a filter substrate provided by an embodiment of the present invention;

[0048] Fig.12 is a schematic diagram of the cross-sectional structure of another filter substrate provided by an embodiment of the present invention;

[0049] Fig.13 It is a schematic structural diagram of a first shielding raw tape provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0050] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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 should fall within the scope of protection of the present invention.

[0051] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0052] The embodiment of the present invention provides an inductor raw tape, which can effectively solve the problem of cutting deviation of inductor branches. Figure 1 Schematic diagram of the structure of an inductor strip provided by an embodiment of the present invention. Figure 1 The inductor tape includes: a first ceramic dielectric layer 110 and an inductor circuit layer printed on one side of the first ceramic dielectric layer 110; the inductor circuit layer includes: at least one inductor structure. Figure 2 is a schematic diagram of an inductor structure provided by an embodiment of the present invention. Figure 1 and Figure 2 The inductor structure includes: at least two parallel inductor branches 12, and a first transition electrode 11 perpendicular to the inductor branches 12; the first transition electrode 11 is arranged on one side of each inductor branch 12 along the extension direction of the inductor branch 12, and connects each inductor branch 12. After being cut, the inductor structure serves as an inductor layer in a comb-shaped bandpass filter; the vertical projection of the cutting line 80 corresponding to the inductor structure on the inductor structure overlaps with the first transition electrode 11; the width d1 of the first transition electrode 11 in the extension direction of the inductor branch 12 is greater than or equal to the stroke error threshold of the cutting deviation of the cutting equipment, so that the length of each inductor branch 12 remains unchanged after cutting, thereby ensuring the accuracy of the inductance value in each order resonance unit in the inductor layer of the comb-shaped bandpass filter.

[0053] Exemplarily, the comb-shaped bandpass filter can be a low temperature co-fired ceramic (LTCC) device, which can be cut from the filter substrate along the cutting line 80. Specifically, the filter substrate serves as the device substrate to be cut, and contains at least one circuit structure of the comb-shaped bandpass filter. The inductor raw tape can be a layer of raw tape used to form the filter substrate, and the filter substrate can also include other raw tapes used to form other circuit structures in the comb-shaped bandpass filter. Each layer of raw tape can be composed of a ceramic dielectric layer and a circuit layer printed on one side of the ceramic dielectric layer. In the filter substrate, each layer of other raw tapes is stacked with the inductor raw tape; and the related circuit structures in the other raw tapes are aligned with each inductor structure in the inductor raw tape, so as to form a functional circuit in the comb-shaped bandpass filter after cutting. The cutting line 80 can be set on the surface of the filter substrate to facilitate the cutting equipment to perform alignment cutting on the filter substrate. Among them, the cutting line 80 can be set along the outer contour of each comb-shaped bandpass filter, and the cutting equipment cuts the filter substrate according to the preset position indicated by the cutting line 80. After removing the excess part, the comb-shaped bandpass filter product can be obtained. Exemplarily, the cutting line 80 can be a linear mark printed on the surface of the filter substrate, or a linear groove opened on the surface of the filter substrate. The specific form is not limited here, as long as it can indicate the cutting position. It can be understood that the position of the vertical projection of the cutting line 80 on each film layer is indicated by a dotted dashed line in each figure. In fact, the cutting line 80 is a visible structure set on the surface of the filter substrate and does not need to be set inside the filter substrate. Exemplarily, alignment marks can be set at appropriate positions in each layer of raw tape of the filter substrate to facilitate the alignment and stacking of each layer of raw tape.

[0054] For ease of display, Figure 1 The example in which the inductor strip includes an inductor structure is given, but it is not intended to limit the present invention. And, Figure 1 and Figure 24 parallel inductor branches 12 are exemplarily provided to form a 4th-order filter. It is understandable that the number of inductor branches 12 here is only for exemplary display and is not a limitation of the present invention. In practical applications, the number of inductor branches 12 in an inductor structure can be set according to demand, for example, 3, 4, 5 or 6. The number of inductor branches 12 is the number of resonant units in the comb-type bandpass filter, and also represents the order of the comb-type bandpass filter. An inductor branch 12 is an inductor in a resonant unit. The order of the comb-type bandpass filter is not limited here, and the order can be any integer ≥2. Among them, the vertical projection of the cutting line 80 corresponding to the inductor structure on the inductor structure does not overlap with each inductor branch 12, and each inductor branch 12 in the inductor structure falls within the product outline framed by the cutting line 80, so that each inductor branch 12 can be not cut during the cutting process of the filter substrate.

[0055] For ease of explanation, the extension direction of the inductor branch 12 is denoted as the first direction X, and the arrangement direction of the inductor branch 12 is denoted as the second direction Y, where the first direction X is perpendicular to the second direction Y. The first transition electrode 11 is disposed perpendicular to the inductor branch 12, which can be understood as follows: the extension direction of the first transition electrode 11 is perpendicular to the extension direction of the inductor branch 12, that is, the first transition electrode 11 extends along the second direction Y. Among them, the first transition electrode 11 is connected to the same side of each inductor branch 12. The effective electrical length of the inductor branch 12 is the distance from the grounding point to the open circuit point of the inductor branch 12; the grounding point of the inductor branch 12 is the end of the inductor branch 12 connected to the first transition electrode 11, and the open circuit point of the inductor branch 12 is the end of the inductor branch 12 away from the first transition electrode 11. Therefore, the effective electrical length of the inductor branch 12 is the length of the inductor branch 12 itself along the first direction X. As Figure 2 The effective electrical length of the leftmost inductor branch 12 is its length d2 along the first direction X.

[0056] In the related art, the influence of cutting deviation can be seen in Figure 3, take the leftmost inductor branch 12 as an example: in the related art, the cutting device directly cuts the inductor raw tape along the cutting line 80, and each inductor branch 12 will be directly cut during the cutting process. Then, corresponding to the position of the upper first edge 81 in the cutting line 80, only when the actual cutting position of the cutting device falls on the position marked by the first edge 81, the length of the inductor branch retained in the comb bandpass filter can maintain the standard length d3; once the cutting device has a cutting deviation, the actual cutting position deviates from the first edge 81, which will cause the length of the inductor branch retained in the comb bandpass filter to deviate from the standard length d3, thereby affecting the inductance value. For example, if the actual cutting position falls on the red dotted line position above the first edge 81, the length of the retained inductor branch will be d4, which is longer than the standard length d3; if the actual cutting position falls on the blue dotted line position below the first edge 81, the length of the inductor branch will be d5, which is shorter than the standard length d3.

[0057] In this embodiment, see Figure 2 , corresponding to the side where each inductor branch 12 is connected to the first transition electrode 11, the cutting line 80 corresponding to the inductor structure includes a first edge 81, and the vertical projection of the first edge 81 on the inductor structure falls within the range of the first transition electrode 11. Then, during the cutting process, corresponding to the side where each inductor branch 12 in the inductor structure is connected to the first transition electrode 11, the cutting device will cut the first transition electrode 11 according to the first edge 81, and will not cut the inductor branch 12 itself, and will not affect the length of the inductor branch 12. In addition, the width d1 of the first transition electrode 11 in the extension direction of the inductor branch 12 is greater than or equal to the stroke error threshold of the cutting deviation of the cutting device. Even if there is a cutting deviation, so that the final cutting position falls on the red dotted line above or the blue dotted line below the first edge 81, the first transition electrode 11 will still be cut, and the length of the inductor branch 12 retained in the comb-shaped bandpass filter obtained after cutting will not be affected, and the length of the inductor branch 12 along the first direction X before and after cutting can be ensured to remain unchanged. The stroke error threshold of the cutting deviation can be determined according to the design of the cutting line, the cutting edge width and the accuracy of the cutting equipment, and then the width d1 of the first transition electrode 11 along the first direction X is determined according to the stroke error threshold.

[0058] In the inductor raw tape provided by the embodiment of the present invention, by setting the first transition electrode 11 in each inductor structure, and setting it on the side of the inductor branch line 12 connected to the first transition electrode 11, the vertical projection of the cutting line 80 corresponding to the inductor structure on the inductor structure overlaps with the first transition electrode 11, and the width d1 of the first transition electrode 11 in the extension direction of the inductor branch line 12 is set to be greater than or equal to the stroke error threshold of the cutting deviation of the cutting device, so that the cutting device can cut the first transition electrode 11 in each inductor structure according to the cutting line 80 during the cutting process. Even if there is a certain cutting deviation of the cutting device, the difference between the product obtained in the case of accurate alignment cutting is only the amount of the first transition electrode 11 retained in the comb bandpass filter, and the cutting deviation no longer affects the length of each inductor branch line 12. The length of the inductor branch line 12 along the extension direction of the inductor branch line 12 before and after cutting remains unchanged, and the effective electrical length of the inductor branch line 12 is not affected, which can eliminate the influence on the inductance value of each resonant unit in the product, thereby avoiding the resulting frequency offset, and improving production consistency and product yield.

[0059] Based on the above embodiments, optionally, see Figure 2 , the cutting line 80 corresponding to the inductor structure includes a first side 81, and the vertical projection of the first side 81 on the inductor structure falls within the range of the first transition electrode 11. The vertical projection of the first side 81 on the inductor structure and the distance d11 between the side of the first transition electrode 11 close to the inductor branch line 12 can be set to be greater than or equal to the stroke error threshold of the cutting deviation. In this way, the cutting head of the cutting device can be oriented in the direction of Figure 2 When the deflection is indicated by the blue dotted line below the first side 81, even if the maximum deflection stroke is reached, the cutter head still cuts the first transition electrode 11 but does not cut the inductor branch 12, ensuring that the length of the inductor branch 12 is not affected by the cutting process.

[0060] The stroke error threshold range of the cutting deviation is, for example, 30um to 100um. It is understandable that the above stroke error threshold is not a limitation of the present invention. According to the different cutting process levels, all implementation methods applied to this patent are within the protection scope of this patent.

[0061] Based on the above embodiments, optionally, see Figure 2 , it is also possible to set the vertical projection of the first side 81 on the inductor structure, and the distance d12 between the side of the first transition electrode 11 away from the inductor branch line 12 to be greater than or equal to the stroke error threshold of the cutting deviation. When the comb-shaped bandpass filter is in use, it is necessary to ground the grounding point of the inductor branch line 12. This embodiment is set in this way so that the cutting head has a direction such as Figure 2When the offset is indicated by the red dotted line above the first edge 81, even if the maximum offset stroke is reached, the cutter head still cuts the first transition electrode 11, thereby ensuring that the electrode material of the first transition electrode 11 can be exposed on the cut surface obtained by cutting along the first edge 81, so as to facilitate the grounding of each inductor branch 12 through the retained first transition electrode 11. In the comb-type bandpass filter product, the retained first transition electrode 11 is connected between the external grounding electrode and each inductor branch 12 to form a new reference ground, and each inductor branch 12 is grounded through the retained first transition electrode 11.

[0062] In one embodiment, optionally, the vertical projection of the first edge 81 on the inductor structure can be set to fall as close as possible to the center position of the first transition electrode 11 along the first direction X, so as to reserve sufficient cutting offset margins in both the upper and lower directions to ensure that the length of each inductor branch 12 is not affected during the cutting process.

[0063] In one embodiment, exemplarily, in the inductor structure, the width of the first transition electrode 11 in the extension direction of the inductor branch 12 (ie, the first direction X) ranges from 30um to 200um, such as 50um, 80um, 100um, 130um or 150um.

[0064] Based on the above embodiments, optionally, there are multiple ways to set the first transition electrode, several of which are exemplarily described below, but are not intended to limit the present invention.

[0065] Continue to see Figure 1 and Figure 2 In one embodiment, optionally, the first transition electrode 11 is an integrated structure, connecting all inductor branches 12 in the same inductor structure. Exemplarily, the first transition electrode 11 is rectangular, and the width d1 of the first transition electrode 11 in the first direction X is the width of the short side of the rectangle.

[0066] Figure 4 FIG. 1 is a schematic diagram of the structure of another inductor strip provided by an embodiment of the present invention. Figure 4 In another embodiment, optionally, in the same inductor structure, the first transition electrode 11 includes: a plurality of sub-electrodes 111 perpendicular to the inductor branch line 12 and arranged along the arrangement direction of the inductor branch line (i.e., the second direction Y); one sub-electrode 111 connects at least one inductor branch line 12, and adjacent sub-electrodes 111 are disconnected. Wherein, the vertical projection of the cutting line 80 corresponding to the inductor structure on the inductor structure overlaps with each sub-electrode 111; the width of any sub-electrode 111 in the extension direction of the inductor branch line 12 is greater than or equal to the above-mentioned stroke error threshold. The width of each sub-electrode 111 in the first direction X can be referred to the description of the first transition electrode 11, and will not be repeated here. Figure 4In the figure, it is shown that a sub-electrode 111 is connected to two inductor branches 12, but this is not intended to limit the present invention. Each sub-electrode 111 may be a rectangle with a long side extending along the second direction Y, which is equivalent to breaking a complete rectangle into a plurality of rectangles arranged along the second direction Y; the short side width of the rectangle of any sub-electrode 111 may represent the width of the first transition electrode 11 in the first direction X.

[0067] In the above embodiments, the related structures of a single inductor structure are mainly described. In the above embodiments, the inductor circuit layer of the inductor tape is exemplified as including an inductor structure, but it is not intended to limit the present invention. In other embodiments, the inductor circuit layer may optionally include multiple inductor structures. The following is an exemplary description of the arrangement of multiple inductor structures in the inductor circuit layer.

[0068] Figure 5 is a schematic diagram of the structure of another inductor strip provided by an embodiment of the present invention. Figure 5 In one embodiment, each inductor structure is optionally arranged in an array in the inductor circuit layer. Exemplarily, the inductor branches 12 in each inductor structure extend in the same direction, so the first direction X can be used as the column direction of the inductor strip, and the second direction Y can be used as the row direction of the inductor strip. The inductor strip can include multiple rows and columns of inductor structures. This arrangement allows multiple inductor structures to be neatly arranged in the inductor circuit layer, and adjacent edges of the cutting lines 80 corresponding to adjacent inductor structures can be spliced ​​into a straight line, which is convenient for cutting equipment to perform cutting.

[0069] Figure 6 is a schematic diagram of the structure of another inductor strip provided by an embodiment of the present invention. Figure 6 In another embodiment, optionally, at least two adjacent inductor structures are mirror-symmetrical along the extension direction of the inductor branch line 12 and share the same first transition electrode 11. In this way, the first edges of the cutting lines 80 corresponding to the two adjacent inductor structures can overlap, thereby reducing the number of cutting times. Figure 6 As shown, corresponding to the two inductor structures on the left, the cutting device only needs to cut once according to the first edge 81 of the two overlapping edges to obtain the upper and lower products, without the need for Figure 5 In the process, two adjacent inductor structures along the first direction X need to be cut along the first side respectively. Moreover, such a setting can realize a more compact arrangement of the inductor structures, increase the utilization rate of the inductor raw tape on the basis of reducing the number of cutting times, reduce the waste generated by cutting, and reduce the preparation cost.

[0070] For example, on the basis of the arrangement of the array of multiple inductor structures, it is possible to arrange that along the first direction X, each two adjacent rows of inductor structures are mirror-symmetrical, for example, each odd-numbered row of inductor structures and the next row of inductor structures can share the first transition electrode 11, or each even-numbered row of inductor structures and the next row of inductor structures can share the first transition electrode 11. In this way, the advantages of the above two embodiments can be combined to achieve a neat and compact arrangement of multiple inductor structures.

[0071] It can be understood that the above-mentioned limitation on the width of the first transition electrode 11 is also applicable to the solution in which two mirror-symmetrical inductance structures share the same first transition electrode 11; it should be noted that, for the two inductance structures sharing the same first transition electrode 11, the side of the first transition electrode 11 close to the inductance branch 12 and the side away from the inductance branch 12 both refer to the inductance branch 12 in the same inductance structure.

[0072] Continue to see Figure 1 On the basis of the above embodiments, optionally, in the inductor structure, the parallel inductor branches 12 constitute an inductor branch group. The inductor structure also includes: two coupling taps 13, which are arranged on both sides of the inductor branch group along the arrangement direction of the inductor branches 12, and each coupling tap 13 is connected to the inductor branch 12 adjacent to it. That is, in an inductor structure, along the second direction Y, there is a coupling tap 13, each inductor branch 12 and another coupling tap arranged in sequence; the two coupling taps are respectively connected to the two inductor branches 12 located on the outside along the second direction Y.

[0073] The vertical projection of the cutting line 80 corresponding to the inductor structure on the inductor structure also overlaps with the two coupling taps 13 respectively. Figure 2 , the cutting line 80 corresponding to the inductor structure may include a second side 82 and a third side 83 arranged in parallel, both of which are perpendicular to the first side 81; the vertical projections of the second side 82 and the third side 83 on the inductor structure overlap with the two coupling taps 13 respectively. In this way, the electrode materials of the two coupling taps 13 can be exposed on the two cutting surfaces obtained by cutting along the second side 82 and the third side 83, so that the two retained coupling taps can be connected to the two transmission electrodes respectively in the future to realize the input and output of the comb-shaped bandpass filter. Among them, when the comb-shaped bandpass filter is in use, the input can be carried out through the retained part of one of the coupling taps 13, and the output can be carried out through the retained part of the other coupling tap 13.

[0074] For example, the width of the coupling tap 13 in the second direction Y can be set to be greater than or equal to the stroke error threshold of the cutting deviation of the cutting device to ensure that the electrode material of the coupling tap can be exposed on the cutting surface after cutting. The distance relationship between the edge of the coupling tap 13 in the second direction Y and the projection of the corresponding edge in the cutting line 80 can refer to the distance relationship between the edge of the first transition electrode 11 in the first direction Y and the projection of the first edge 81, which will not be repeated here.

[0075] For example, the length of the first transition electrode 11 in the second direction Y can be set to be greater than the length of the inductor branch line group in the second direction Y, and less than the spacing between the second side 82 and the third side 83 in the second direction Y; and the vertical projections of the second side 82 and the third side 83 on the inductor structure are set not to overlap with the first transition electrode 11. In this way, it can be ensured that the first transition electrode 11 is well connected with each inductor branch line 12, and at the same time, it can be ensured that the electrode material of the first transition electrode 11 is not exposed on the two cut surfaces obtained by cutting along the second side 82 and the third side 83, so that the ground electrode prepared subsequently can completely cover the remaining exposed part of the first transition electrode 11 on the cut surface, avoiding the problems such as short circuit caused by the exposed part of the retained first transition electrode 11 in the final comb-shaped bandpass filter product.

[0076] Continue to see Figure 6 On the basis of the above embodiments, optionally, the inductor circuit layer includes a plurality of inductor structures; wherein at least two adjacent inductor structures are mirror-symmetrical along the arrangement direction of the inductor branches (i.e., the second direction Y), and two adjacent coupling taps 13 in the two mirror-symmetrical inductor structures along the second direction Y are connected as one. In this way, for the second side 82 (or as Figure 6 The third side 83 in the figure can overlap. Then, if Figure 6 As shown, corresponding to the two inductor structures below, the cutting equipment only needs to perform one cut according to the third side 83 where the two overlap, and two products on the left and right can be obtained. This arrangement can achieve a tighter arrangement of the inductor structure, increase the utilization rate of the inductor raw tape on the basis of reducing the number of cuts, reduce the waste generated by cutting, and reduce the preparation cost. It can be understood that in each filter monomer obtained by cutting, at least part of each coupling tap is retained in the inductor layer, and the retained part of each coupling tap has electrode material exposed on the cutting surface.

[0077] The embodiment of the present invention further provides a method for preparing a comb-shaped bandpass filter, and the inductor layer in the comb-shaped bandpass filter is prepared based on the inductor raw tape provided by any of the above embodiments, which has corresponding beneficial effects. Figure 7 is a flow chart of a method for preparing a comb-shaped bandpass filter provided by an embodiment of the present invention. Figure 7 The preparation method of the comb-shaped bandpass filter comprises the following steps:

[0078] S110, providing a filter substrate.

[0079] The filter substrate includes the inductor green tape provided in any embodiment of the present invention; and the surface of the filter substrate is provided with cutting lines corresponding to each inductor structure in the inductor green tape.

[0080] S120, cutting the filter substrate along the cutting line to obtain comb-shaped bandpass filters.

[0081] After cutting the filter substrate along the cutting line, each filter monomer can be obtained; the filter monomer can be directly used as a comb-shaped bandpass filter, or form a comb-shaped bandpass filter after necessary subsequent processing. The cutting line corresponding to an inductor structure can be understood as the cutting line required to cut a filter monomer, for example, including four edges around the outline of the filter monomer.

[0082] Based on the above embodiments, optionally, the comb-shaped bandpass filter is a low-temperature co-fired ceramic device, which is prepared by multi-layer ceramic co-firing technology. Figure 8 Each resonant unit in the comb bandpass filter can include an inductor and a capacitor. The inductor and the capacitor are physically implemented in each circuit layer, and finally stacked and co-fired into a filter. Among them, the coupling between the resonant units can be adjusted by changing the spacing between the parallel resonant units, such as changing the spacing between the inductor branches. Figure 8 For example, the thickness direction of the comb-shaped bandpass filter is recorded as the third direction Z, which is perpendicular to both the first direction X and the second direction Y. The vertical projection of any structure mentioned in this application on other structures refers to the orthographic projection along the third direction Z.

[0083] Specifically, providing the filter substrate may include the following steps:

[0084] 1) Prepare a plurality of green tapes separately.

[0085] The plurality of raw strips include: an inductor raw strip, a first capacitor raw strip and a cross-coupling raw strip. The structure of the inductor raw strip can refer to the description of the above embodiments, which will not be repeated here. The inductor structure is cut to form the inductor layer 10 in the comb-shaped bandpass filter. The structure of the first capacitor raw strip can refer to Fig. 9 The first capacitor strip includes a second ceramic dielectric layer 210 and a first capacitor circuit layer 220 printed on one side of the second ceramic dielectric layer 210. The first capacitor circuit layer 220 includes the same number of first capacitor structures as the number of inductor structures. Fig. 9A first capacitor structure is given as an example. In the filter matrix, each inductor structure is arranged in one-to-one correspondence with each first capacitor structure; after cutting, the first capacitor structure forms the first capacitor layer 20 in the comb-shaped bandpass filter. The first capacitor structure includes at least two first capacitor branches 22 arranged in parallel. The structure of the cross-coupled raw band can be seen in Fig.10 The cross-coupling tape includes a third ceramic dielectric layer 310 and a cross-coupling circuit layer 320 printed on one side of the third ceramic dielectric layer 310. The cross-coupling circuit layer 320 includes the same number of cross-coupling structures as the inductor structures. Fig.10 A cross-coupling structure is given as an example. In the filter matrix, each inductance structure is arranged in correspondence with each cross-coupling structure, and the cross-coupling structure is cut to form a cross-coupling layer 30 in the comb-type bandpass filter. The cross-coupling structure includes two parallel coupling branches, namely a first coupling branch 311 and a second coupling branch 312, and a connecting branch 313 connecting the two coupling branches. The two coupling branches are connected to the connecting branch 313 in a Z shape.

[0086] Understandably, Figure 8 The circuit structures shown in FIG. 1 are retained in the comb-shaped bandpass filter product obtained after cutting, corresponding to Figure 1 , Fig. 9 and Fig.10 The circuit pattern structure retained within the outline framed by the cutting line 80. Exemplarily, the materials of each circuit layer are the same, for example, they are all metal materials, specifically silver. The functional circuit structure in each circuit layer may have an extension portion located outside the cutting line 80 at the location where it needs to be exposed to the cutting surface after cutting, so that it can still be exposed on the cutting surface in the case of cutting deviation.

[0087] 2) Stack the green tapes to form a filter substrate.

[0088] The lamination process may specifically be as follows: stacking the prepared green tapes together and combining them tightly by heat pressing. Fig.11 is a schematic diagram of a cross-sectional structure of a filter substrate provided by an embodiment of the present invention, which may correspond to Figure 8Structural diagram of the middle section A position. During the lamination process, each layer of raw tape can be stacked in the order of stacking the inductor raw tape, the first capacitor raw tape and the cross-coupling raw tape in sequence (for example, from top to bottom). Among them, each circuit layer is located on the same side of the corresponding ceramic dielectric layer along the third direction Z. For example, in the inductor raw tape, the inductor circuit layer 120 is located above the first ceramic dielectric layer 110; in the first capacitor raw tape, the first capacitor circuit layer 220 is located above the second ceramic dielectric layer 120; in the cross-coupling raw tape, the cross-coupling circuit layer 320 is arranged above the third ceramic dielectric layer 310. There is a ceramic dielectric layer between each two adjacent circuit layers. During the lamination process, the side of the ceramic dielectric layer in the upper raw tape without the printed circuit layer contacts the side of the circuit layer in the lower raw tape away from the ceramic dielectric layer.

[0089] In the laminated filter matrix, the alignment relationship of each layer of circuit structure in the same comb-shaped bandpass filter is as follows: the first capacitor branch 22 and the coupling branch are both parallel to the inductor branch 12, that is, the first capacitor branch 22 and the coupling branch extend along the first direction X.

[0090] Among them, in each layer of the circuit structure in the same comb-shaped bandpass filter, the number of each inductor branch 12 in the inductor structure and each first capacitor branch 22 in the first capacitor structure are the same and correspond one to one, and the vertical projection of the first capacitor branch 22 on the inductor structure overlaps with the inductor branch 12 corresponding to the first capacitor branch 22, for example, partially overlaps or completely overlaps. A group of inductor branches 12 and corresponding first capacitor branches 22 can constitute a resonance unit. Among them, a single inductor branch 12 can be equivalent to an inductor in a resonance unit; the inductor branch 12 and the first capacitor branch 22 can be relatively equivalent to capacitors in the resonance unit. In this way, the inductor plus the capacitor loaded at the end (open end) can form an LC resonance. Exemplarily, the length of the inductor branch 12 can be a quarter wavelength of the resonance frequency; by loading a capacitor at the end, the length of the inductor branch 12 can be reduced, thereby reducing the size of the device; wherein, the larger the loaded capacitance value, the smaller the length of the inductor branch 12 can be. The capacitance value can be determined by the facing area, distance and dielectric constant of the two plates.

[0091] The two coupling branches in the cross-coupling structure correspond to two of the inductance branches 12 of the inductance structure, respectively, and the vertical projection of the coupling branch on the inductance structure overlaps with the inductance branch 12 corresponding to the coupling branch, for example, partially overlaps or completely overlaps. The cross-coupling structure can play a role of cross-coupling, and if the design requires coupling of electromagnetic fields between several orders, coupling branches can be set corresponding to the above two orders of inductance branches 12. Figure 8For example, if the first-order and fourth-order resonance units need to be coupled, the first coupling branch line 311 can be arranged below the inductance branch line 12 of the first-order resonance unit, and the second coupling branch line 312 can be arranged below the inductance branch line 12 of the fourth-order resonance unit.

[0092] It can be understood that in the filter matrix, in the same comb-type bandpass filter, each first capacitor branch 22, each coupling branch and connecting branch 313 are all located within the outline framed by the cutting line 80, so that the comb-type bandpass filter obtained after cutting retains the complete first capacitor branches 22, each coupling branch and connecting branch 313.

[0093] Continue to see Fig. 9 On the basis of the above embodiments, optionally, the first capacitor structure further includes a second transition electrode 21 perpendicular to the first capacitor branch line 22. In the related structure of the same comb-shaped bandpass filter of the filter substrate, the second transition electrode 21 is arranged on one side of each first capacitor branch line 22 along the extension direction of the inductance branch line (i.e., the first direction X), and connects each first capacitor branch line 22. Among them, the first transition electrode 11 and the second transition electrode 21 are arranged on both sides of the related structure of the same comb-shaped bandpass filter along the first direction X.

[0094] Among them, corresponding to the side where each first capacitor branch 22 is connected to the second transition electrode 21, the vertical projection of the cutting line 80 on the first capacitor structure overlaps with the second transition electrode 21, and the width of the second transition electrode 21 in the first direction X is greater than or equal to the stroke error threshold, so that the length of each first capacitor branch 22 in the first capacitor structure after cutting remains unchanged.

[0095] In this embodiment, see Fig. 9 , the cutting line 80 corresponding to the inductor structure, that is, the cutting line 80 corresponding to the comb-shaped bandpass filter, also includes a fourth side 84 arranged opposite to and parallel to the first side 81. The vertical projection of the fourth side 82 on the first capacitor structure falls within the range of the second transition electrode 21. Then, during the cutting process, corresponding to the side of each first capacitor branch 22 connected to the second transition electrode 21, the cutting device will cut the second transition electrode 21, but will not cut the first capacitor branch 22 itself, and will not affect the length of each first capacitor branch 22, thereby ensuring that the capacitance value of the capacitor in each resonant unit is not affected by the cutting deviation.

[0096] On the basis of the above embodiments, optionally, the vertical projection of the fourth side 84 on the first capacitor structure and the distance d61 between the side of the second transition electrode 21 close to the first capacitor branch 22 can be set to be greater than or equal to the stroke error threshold of the cutting deviation. And / or, the vertical projection of the fourth side 84 on the first capacitor structure and the distance d62 between the side of the second transition electrode 21 away from the first capacitor branch 22 can be set to be greater than or equal to the stroke error threshold of the cutting deviation. And / or, the width d6 of the second transition electrode 21 in the first direction X can be set to be in the range of: 30um-200um, for example, 50um, 80um, 100um, 130um or 150um, etc. The reasons for the above settings can be found in the relevant description of the first transition electrode 11, which will not be repeated here.

[0097] The above embodiments exemplarily provide a configuration method of a capacitor in a resonant unit, but are not intended to limit the present invention. In other embodiments, optionally, see Fig.12 You can also use a VIC capacitor (Vertically-Interdigitated-Capacitor) structure, use multilayer ceramic technology to design a multilayer cross-structure capacitor, and use the upper and lower sub-capacitors in parallel to achieve a large capacitor, thereby increasing the capacitance value without substantially increasing the device size.

[0098] Specifically, the plurality of raw tapes also include: a second capacitor raw tape, the second capacitor raw tape includes a fourth ceramic dielectric layer 410 and a second capacitor circuit layer 420 printed on one side of the fourth ceramic dielectric layer 410. The second capacitor circuit layer 420 includes the same number of second capacitor structures as the inductance structure. The second capacitor structure includes at least two second capacitor branches arranged in parallel. The second capacitor structure forms the second capacitor layer in the comb-shaped bandpass filter after cutting. Wherein, when each raw tape is stacked, the second capacitor raw tape is arranged between the first capacitor raw tape and the cross-coupling raw tape. In the filter matrix, the second capacitor branch is parallel to the inductance branch 12, and in the same comb-shaped bandpass filter, the number of each first capacitor branch 22 and each second capacitor branch is the same and one-to-one corresponding, and the vertical projection of the second capacitor branch on the first capacitor structure overlaps with the first capacitor branch 22 corresponding to the second capacitor branch, for example, partially overlaps or completely overlaps. In addition, each second capacitor branch is connected to each inductance branch 12 in a one-to-one correspondence, for example, through a through hole or an external electrode. In this arrangement, a corresponding group of inductor branches 12, first capacitor branches 22 and second capacitor branches form a resonant unit; wherein, the inductor branch 12 and the first capacitor branch 22 relatively form a sub-capacitor, the first capacitor branch 22 and the second capacitor branch relatively form another sub-capacitor, and the first capacitor branch 22 serves as a common plate of the two sub-capacitors.

[0099] See also Fig.11 and Fig.12 , based on the above embodiments, optionally, the multiple raw tapes also include: a first shielding raw tape, the first shielding raw tape includes a fifth ceramic dielectric layer 511 and a first shielding circuit layer 521 printed on one side of the fifth ceramic dielectric layer 511. The first shielding circuit layer 521 includes the same number of first shielding structures as the inductance structure. In the filter matrix, each inductance structure is arranged one-to-one with each first shielding structure; after cutting, the first shielding structure constitutes the first shielding layer 501 in the comb-shaped bandpass filter, and the first shielding layer 501 can be grounded through the grounding electrode outside the filter. When stacking the raw tapes, the first shielding raw tape is arranged on the side of the inductance raw tape away from the first capacitance raw tape. The structure of the first shielding structure can be seen in Fig.13 , the first shielding structure includes a first shielding pattern 52 and at least one first opening 51. Among them, since the comb-shaped bandpass filter belongs to a surface microstrip structure, there are parasitic effects and transmission line effects, and the external electromagnetic isolation and anti-interference capabilities are relatively poor. In this embodiment, the comb-shaped bandpass filter includes a first shielding layer 501, which can effectively reduce the external radiation interference of the filter and also play a role in resisting external interference.

[0100] The first opening 51 is provided to control the surface area of ​​the first shielding pattern 52 on the fifth ceramic dielectric layer 511 in the raw tape. A certain gap is left through the first opening 51 for the combination of the upper and lower ceramic dielectrics, so that the contact area of ​​the upper and lower ceramic dielectrics is sufficient to avoid the problem of fault peeling in the product. Each first opening 51 can be at least partially located within the contour range framed by the cutting line 80. The first shielding pattern 52 can be a circuit pattern with as large an area as possible, covering each resonant unit as much as possible. The position and size of each first opening 51 can be adjusted according to the results of the simulated shielding effect to ensure the shielding effect of the first shielding pattern 52 as much as possible. It can be understood that Fig.13 The first shielding pattern 52 shown is a rectangle with four openings on four sides. This specific figure is only used as an exemplary illustration, but not as a limitation of the present invention. All implementation methods applied to this patent are within the scope of protection of this patent, regardless of the size and shape of the ground layer.

[0101] Among them, when the comb bandpass filter is soldered to the circuit board, it corresponds to Figure 8 The lower surface of the filter is welded to the circuit board, and the first shielding layer 501 serves as the grounding layer inside the filter, and can cooperate with the grounding structure in the circuit board to achieve the elimination of electromagnetic radiation and resistance to external interference of the comb-shaped bandpass filter.

[0102] On the basis of the above-mentioned embodiments, optionally, the plurality of raw tapes further include: a second shielding raw tape, the second shielding raw tape includes a sixth ceramic dielectric layer 512 and a second shielding circuit layer 522 printed on one side of the sixth ceramic dielectric layer 512. The second shielding circuit layer 522 includes the same number of second shielding structures as the inductance structures. In the filter matrix, each inductance structure is arranged one-to-one with each second shielding structure; after cutting, the second shielding structure forms the second shielding layer 502 in the comb-shaped bandpass filter, and the second shielding layer 502 can be grounded through the grounding electrode outside the filter. When the raw tapes are stacked, the second shielding raw tape is arranged on the side of the cross-coupling raw tape away from the first capacitor raw tape. Among them, the structure of the second shielding structure can refer to the description of the first shielding structure. The second shielding structure may include a second shielding pattern and at least one second opening. A certain gap can be left through the second opening for the combination of the upper and lower ceramic dielectrics of the second shielding structure.

[0103] In one embodiment, illustratively, see Figure 8 , a first shielding layer 501 and a second shielding layer 502 can be set in the comb-type bandpass filter. In this way, a grounded shielding layer is introduced on both sides of the resonant unit, that is, the upper and lower sides, respectively, which can greatly enhance the anti-interference ability of the comb-type bandpass filter, and can also effectively prevent the radio frequency signal passing through the comb-type bandpass filter from interfering with adjacent devices, thereby greatly improving the reliability of the comb-type bandpass filter and the system in which it is located.

[0104] See also Fig.11 and Fig.12 It is understandable that a ceramic dielectric layer may be provided on the side of the first shielding circuit layer 521 away from the fifth ceramic dielectric layer 511, so that both sides of the filter substrate along the third direction Z are covered by the ceramic dielectric layer to prevent the circuit layer from being exposed.

[0105] On the basis of the above embodiments, optionally, the inductor structure includes an inductor branch 12, a first transition electrode 11 and a coupling tap 13. The filter substrate is cut along the cutting line 80 to obtain each filter monomer. In the preparation method of the comb-shaped bandpass filter, after obtaining each filter monomer, a series of subsequent treatments are required to obtain each comb-shaped bandpass filter, specifically including:

[0106] 1) Each filter monomer is sintered to form a sintered monomer.

[0107] In this step, debinding can be performed first to remove organic matter between the green tapes, and co-firing can be performed at a low temperature so that the ceramic media of each green tape in the cut filter monomer are sintered into a solid integrated structure.

[0108] When the green tapes of the filter monomer are sintered, the ceramic dielectric layers on both sides of each circuit layer are combined at positions other than the circuit pattern. For example, the two ceramic dielectric layers on both sides of the first shielding layer are combined at the first opening; and the two ceramic dielectric layers on both sides of the second shielding layer are combined at the second opening.

[0109] 2) preparing a ground electrode and a transmission electrode on the periphery of each sintered monomer to form each comb-shaped bandpass filter; wherein, in the comb-shaped bandpass filter, each inductor branch is connected to the ground electrode through the first transition electrode retained after cutting, and the coupling tap retained after cutting is connected to the transmission electrode.

[0110] Among them, the ground electrode and the transmission electrode are both external electrodes to achieve electrical connection with other devices. The external electrode can be in a cap-shaped or C-shaped sleeve on the periphery of the sintered monomer. In the sintered monomer, the parts of each circuit structure that need to be connected to the external electrode can be exposed on the cutting surface. When the external electrode is sleeved on the sintered monomer, the external electrode directly contacts the corresponding circuit structure to achieve electrical connection.

[0111] In the comb bandpass filter, the inductor layer, the first capacitor layer, the cross-coupling layer, the first shielding layer and the second shielding layer are all connected to the ground electrode. Specifically, each inductor branch 12, each first capacitor branch 22 and each coupling branch are all connected to the ground electrode, and at least part of the inductor branch 12 is also connected to the transmission electrode through the retained coupling tap 13. The first shielding layer 501 and the second shielding layer 502 are both connected to the ground electrode, and specifically, the first shielding pattern and the second shielding pattern are both connected to the ground electrode. It can be understood that the first shielding layer 501 and the second shielding layer 502 do not need to be connected to the transmission electrode, so the first shielding pattern and the second shielding pattern can avoid the transmission electrode setting and do not contact any transmission electrode.

[0112] Specifically, for any sintered monomer, a grounding electrode and a transmission electrode are prepared on the periphery of the sintered monomer, including: preparing two grounding electrodes on opposite sides of the sintered monomer along the extension direction of the inductor branch line, and preparing two transmission electrodes on opposite sides of the sintered monomer along the arrangement direction of the inductor branch line.

[0113] Among them, see Figure 1 , a coupling tap 13 is provided on both sides of the inductor structure along the second direction Y, and the coupling tap 13 is connected to the adjacent inductor branch line 12. In the inductor structure, the first transition electrode 11, each inductor branch line 12 and each coupling tap 13 are physically connected as a whole and can be prepared in the same process. Figure 8The two transmission electrodes include a first transmission electrode 701 and a second transmission electrode 702, one of which can be used as an input electrode and the other can be used as an output electrode. The remaining parts of the two coupling taps 13 after cutting are connected to the two transmission electrodes respectively.

[0114] The grounding point of each inductor branch line 12 is connected to one of the grounding electrodes, and the grounding point of the inductor branch line 12 is one end of the inductor branch line 12 connected to the first transition electrode 11. Each first capacitor branch line 22 is connected to another grounding electrode. Figure 8 , exemplarily, the two grounding electrodes are respectively a first grounding electrode 601 and a second grounding electrode 602. The first grounding electrode 601 is, for example, arranged on one side of the first transition electrode 11. When the first transition electrode 11 is still retained after cutting, the first transition electrode 11 directly contacts the first grounding electrode 601 to form a new reference ground, so that the grounding surface originally formed by the first grounding electrode 601 extends a certain distance to the inside of the monomer after sintering, and the grounding point of each inductor branch 12 is grounded through the first transition electrode 11; the first grounding electrode 601 covers the part of the first transition electrode 11 exposed on the cutting surface. When the first transition electrode 11 is not retained after cutting, the grounding point of each inductor branch 12 is directly connected to the first grounding electrode 601. The second grounding electrode 602 is, for example, arranged on one side of the second transition electrode 21. When the second transition electrode 21 is still retained after cutting, the second transition electrode 21 directly contacts the second grounding electrode 602, and each first capacitor branch 22 is grounded through the second transition electrode 21; the second grounding electrode 602 covers the part of the second transition electrode 21 exposed on the cutting surface. When the second transition electrode 21 is not retained after cutting, each first capacitor branch line 22 is directly connected to the second grounding electrode 602 .

[0115] The two coupling branches are connected to two ground electrodes respectively. Specifically, along the first direction X, one end of the first coupling branch 311 is connected to one ground electrode, and the other end is connected to the connecting branch 313; one end of the second coupling branch 312 is connected to another ground electrode, and the other end is connected to the connecting branch 313. The first shielding layer 501 is connected to the two ground electrodes respectively, and the second shielding layer 502 is connected to the two ground electrodes respectively.

[0116] In summary, the method for preparing the comb bandpass filter provided in the embodiment of the present invention does not adjust the cutting equipment. When the current cutting process level cannot eliminate the cutting deviation, the influence of the cutting deviation is eliminated by designing the circuit layer structure. At the same time, by setting a ground layer, electromagnetic external radiation can be effectively eliminated and the anti-interference performance of the device can be improved.

[0117] An embodiment of the present invention further provides a comb-shaped bandpass filter, which is prepared by the preparation method of the comb-shaped bandpass filter provided by any embodiment of the present invention and has corresponding beneficial effects.

[0118] It should be noted that in each embodiment of the preparation method, specific descriptions are given for different comb-type bandpass filter structures, and these structures can all be considered as the structures of the comb-type bandpass filter provided in the embodiments of the present invention, and the repeated contents will not be repeated here.

[0119] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0120] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An inductive tape, characterized in that: include: A first ceramic dielectric layer and an inductor circuit layer printed on one side of the first ceramic dielectric layer; The inductor circuit layer includes: at least one inductor structure; The inductor structure comprises: at least two inductor branches arranged in parallel, and a first transition electrode arranged perpendicular to the inductor branches; the first transition electrode is arranged on one side of each of the inductor branches along the extension direction of the inductor branches, and connects each of the inductor branches; Among them, the inductor structure is used as the inductor layer in the comb bandpass filter after cutting; the vertical projection of the cutting line corresponding to the inductor structure on the inductor structure overlaps with the first transition electrode; the width of the first transition electrode in the extension direction of the inductor branch line is greater than or equal to the stroke error threshold of the cutting deviation of the cutting equipment.

2. The inductor tape according to claim 1, characterized in that: The inductor circuit layer includes a plurality of the inductor structures; Wherein, a plurality of the inductor structures are arranged in an array in the inductor circuit layer; And / or, at least two adjacent inductor structures are mirror-symmetrical along the extension direction of the inductor branch line and share the same first transition electrode.

3. The inductor tape according to claim 1, characterized in that: The first transition electrode is an integrated structure, connecting all the inductor branches in the same inductor structure; Alternatively, in the same inductor structure, the first transition electrode comprises: a plurality of sub-electrodes perpendicular to the inductor branches and arranged along the arrangement direction of the inductor branches; and one sub-electrode is connected to at least one of the inductor branches.

4. The inductive tape according to any one of claims 1 to 3, characterized in that: The cutting line corresponding to the inductor structure includes a first side, and a vertical projection of the first side on the inductor structure falls within the range of the first transition electrode; a distance between the vertical projection of the first side on the inductor structure and a side of the first transition electrode close to the inductor branch line is greater than or equal to the stroke error threshold; And / or, the cutting line corresponding to the inductor structure includes a first side, a vertical projection of the first side on the inductor structure falls within the range of the first transition electrode; and a distance between the vertical projection of the first side on the inductor structure and a side of the first transition electrode away from the inductor branch line is greater than or equal to the stroke error threshold; And / or, the range of the stroke error threshold is: 30-100um; And / or, the width of the first transition electrode in the extension direction of the inductor branch line is in the range of 30-200 um.

5. The inductive tape according to any one of claims 1 to 3, characterized in that: In the inductor structure, the inductor branches arranged in parallel form an inductor branch group; the inductor structure also includes: two coupling taps, which are arranged on both sides of the inductor branch group along the arrangement direction of the inductor branches, and each coupling tap is connected to the inductor branch adjacent to it; Wherein, the vertical projection of the cutting line corresponding to the inductor structure on the inductor structure also overlaps with the two coupling taps respectively.

6. The inductor tape according to claim 5, characterized in that: The inductor circuit layer includes a plurality of the inductor structures; wherein at least two adjacent inductor structures are mirror-symmetrical along the arrangement direction of the inductor branches, and two adjacent coupling taps in the two mirror-symmetrical inductor structures are connected as one.

7. A method for preparing a comb-shaped bandpass filter, characterized in that: include: A filter substrate is provided; wherein the filter substrate comprises an inductor strip as claimed in any one of claims 1 to 6; and a cutting line corresponding to each of the inductor structures in the inductor strip is arranged on the surface of the filter substrate; The filter substrate is cut along the cutting line to obtain comb-shaped bandpass filters.

8. The method for preparing a comb-shaped bandpass filter according to claim 7, characterized in that: The inductor structure includes an inductor branch line, a first transition electrode and a coupling tap; the filter substrate is cut along the cutting line to obtain each filter monomer; After obtaining each filter monomer, it also includes: Sintering each of the filter monomers to form a sintered monomer; A grounding electrode and a transmission electrode are prepared on the periphery of each of the sintered monomers to form each of the comb-shaped bandpass filters; wherein, in the comb-shaped bandpass filters, each of the inductance branches is connected to the grounding electrode through the first transition electrode retained after cutting, and the coupling tap retained after cutting is connected to the transmission electrode.

9. The method for preparing a comb-shaped bandpass filter according to claim 8, characterized in that: The filter matrix also includes: A first capacitor strip includes a first capacitor circuit layer; the first capacitor circuit layer includes a first capacitor structure corresponding to the inductor structure one by one; the first capacitor structure is cut to serve as a first capacitor layer in a comb-shaped bandpass filter, and the first capacitor layer is connected to the ground electrode; A cross-coupling raw tape, comprising a cross-coupling circuit layer; the cross-coupling circuit layer comprises a cross-coupling structure corresponding to the inductance structure one by one; the cross-coupling structure is cut to serve as a cross-coupling layer in a comb-type bandpass filter, and the cross-coupling layer is connected to the ground electrode; Wherein, in the filter substrate, the inductor strip, the first capacitor strip and the cross-coupling strip are stacked in sequence; The filter substrate further includes: at least one of a first shielding raw tape and a second shielding raw tape; The first shielding raw tape comprises a first shielding circuit layer, wherein the first shielding circuit layer comprises a first shielding structure corresponding to the inductance structure one by one; the first shielding structure is cut to serve as a first shielding layer in a comb-shaped bandpass filter, and the first shielding layer is connected to the ground electrode; the first shielding raw tape is arranged on a side of the inductance raw tape away from the first capacitance raw tape; The second shielding raw tape includes a second shielding circuit layer, and the second shielding circuit layer includes a second shielding structure corresponding to the inductance structure one by one; the second shielding structure is used as the second shielding layer in the comb bandpass filter after cutting, and the second shielding layer is connected to the ground electrode; the second shielding raw tape is arranged on the side of the cross-coupling raw tape away from the first capacitor raw tape.

10. A comb-type bandpass filter, characterized in that: The comb-shaped bandpass filter is prepared by the preparation method described in any one of claims 7 to 9.

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