Chip type radio frequency attenuator with via interconnection structure
By employing a via interconnect structure in the chip RF attenuator, and utilizing the metal conductors filling the vias in the substrate to achieve circuit connection between the front and back sides, the problem of easy damage to the side conductors is solved, improving the stability and reliability of the circuit, making it suitable for harsh environments such as aerospace and military equipment.
Patent Information
- Application Number
- CN202522034420.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-22
- Publication Date
- 2026-08-25
- Estimated Expiration
- 2035-09-22
AI Technical Summary
Existing chip-type RF attenuators have their side conductors exposed in the external environment, making them susceptible to mechanical scratches, chemical corrosion, and physical impacts. This results in poor reliability and environmental adaptability, making it difficult to meet the demands of demanding applications such as aerospace and military equipment.
The via interconnect structure is adopted. By setting vias that run through the thickness of the substrate and filling them with metal conductors, the electrical connection of the conductor circuits on the front and back sides is realized, avoiding the exposure of the side conductors.
It improves the stability and reliability of circuit connections, reduces signal transmission path loss, and enhances the long-term reliability and environmental durability of products.
Smart Images
Figure CN224683351U_ABST
Abstract
Description
Technical Field
[0001] This utility model specifically relates to a chip-type radio frequency attenuator with a via interconnect structure. Background Technology
[0002] Radio frequency (RF) attenuators are important passive devices used to control signal strength, achieve impedance matching, and expand dynamic range. They are widely used in various RF systems such as communications, radar, and test and measurement. Chip RF attenuators have become key components in modern electronic devices due to their small size, stable performance, and ease of integration.
[0003] Currently, conventional thick-film RF attenuators in the industry generally use ceramic substrates as the basic carrier. Front and back circuits are fabricated on the front and back sides of the ceramic substrate, respectively, and the conduction of the front and back circuits is achieved through the connection circuits set on the side of the ceramic substrate.
[0004] While the aforementioned structure using side conductor interconnects offers advantages such as simple manufacturing processes and low cost, it suffers from an inherent and serious reliability flaw: the side conductors connecting the front and back circuits are directly exposed to the external environment of the ceramic substrate, lacking effective protection. This structure makes the side conductors highly susceptible to external environmental factors such as mechanical scratches, chemical corrosion, contamination, or physical impacts during product manufacturing processes (e.g., handling, assembly, welding) and customer applications (e.g., long-term operation in harsh environments). This can lead to damage, breakage, or oxidation of the side conductors, resulting in performance degradation or even complete failure of the RF attenuator.
[0005] Therefore, the long-term reliability and environmental adaptability of traditional chip RF attenuators based on side conductor interconnect technology are greatly limited, making it difficult to meet the needs of applications with extremely stringent requirements for component reliability, such as aerospace, military equipment, high-end medical equipment, and industrial control.
[0006] In summary, there is an urgent need in this field for a novel chip-type RF attenuator structure that can fundamentally solve the reliability problem of external connecting conductors while maintaining excellent RF performance, so as to meet the market demand for high-reliability RF components. Utility Model Content
[0007] To address the aforementioned technical problems, this invention proposes a chip-type RF attenuator with a via interconnect structure.
[0008] To achieve the above objectives, the technical solution of this utility model is as follows:
[0009] This utility model discloses a chip radio frequency attenuator with a via interconnect structure, including: a substrate, a front conductor circuit and several thick film resistors disposed on the front side of the substrate, and a back conductor circuit disposed on the back side of the substrate.
[0010] At least one via is provided on the substrate, extending through its thickness direction, and the via is filled with a metal conductor, which can electrically connect the front conductor circuit and the back conductor circuit.
[0011] Based on the above technical solution, the following improvements can be made:
[0012] As a preferred option, the substrate has a rectangular block structure.
[0013] As a preferred embodiment, the reverse conductor circuit includes: a plurality of conductive strips distributed on the reverse side of the substrate, forming a signal input electrode, a signal output electrode, and a working ground electrode;
[0014] The signal input electrode and the signal output electrode are symmetrically distributed at the edge of the substrate with the central axis of the substrate width direction as the axis of symmetry.
[0015] The working electrode has a T-shaped structure, which includes a transverse electrode portion extending along the length direction of the substrate and a longitudinal electrode portion extending along the width direction of the substrate. The longitudinal electrode portion is placed between the signal input electrode and the signal output electrode, separating the signal input electrode and the signal output electrode.
[0016] As a preferred embodiment, the front conductor circuit includes:
[0017] The first conductive strip extends along the length of the substrate and corresponds to the distribution area of the transverse electrode portion of the working ground electrode.
[0018] The second conductive strip is disposed at the center of the front side of the substrate and corresponds to the distribution area of the longitudinal electrode portion of the working ground electrode.
[0019] The third conduction band corresponds to the distribution area of the signal input electrodes;
[0020] The fourth conduction band corresponds to the distribution area of the signal output electrodes.
[0021] As a preferred embodiment, three thick-film resistors are disposed on the front side of the substrate, including:
[0022] The first thick film resistor has its two ends electrically connected to the first conductive band and the second conductive band, respectively;
[0023] The second thick-film resistor has its two ends electrically connected to the second and third conductive bands, respectively;
[0024] The third thick-film resistor is electrically connected at both ends to the second and fourth conductive bands, respectively.
[0025] As a preferred embodiment, four vias are provided on the substrate, including: a first via, a second via, a third via, and a fourth via;
[0026] The first via and the second via are respectively located on two edges of the first conductor near its length direction. The metal conductors filled in both are used to electrically connect the first conductor to the transverse electrode portion of the working ground electrode.
[0027] The third via is located in the corresponding area of the third conductor, and the metal conductor filled in it is used to electrically connect the third conductor and the signal input electrode.
[0028] The fourth via is located in the corresponding area of the fourth conductor, and the metal conductor inside it is used to electrically connect the fourth conductor to the signal output electrode.
[0029] As a preferred embodiment, the first guide strip, the second guide strip, the third guide strip, and the fourth guide strip all have widened portions at the locations where through holes are provided, and the width of the widened portions is greater than the width of other portions of the guide strips in which they are located.
[0030] As a preferred embodiment, the cross-sections of the first via, the second via, the third via, and the fourth via are all elliptical.
[0031] As a preferred embodiment, the major axis of the elliptical cross-section of the first and second vias is aligned with the length direction of the substrate.
[0032] The major axis of the elliptical cross-sections of the third and fourth vias is aligned with the width direction of the substrate.
[0033] As a preferred embodiment, one or more stacked dielectric protective layers are covered on the surface of the front conductor circuit and the thick film resistor.
[0034] This utility model discloses a chip-type radio frequency attenuator with a via interconnection structure, which has the following beneficial effects:
[0035] First, it breaks through the structural limitations of traditional side conductors connecting the front and back circuits. By filling the vias in the substrate with metal conductors, the electrical connection between the front and back conductor circuits is achieved. This avoids the problem of exposed side conductors being susceptible to environmental corrosion and damage, and greatly improves the stability and reliability of the circuit connection.
[0036] Secondly, the via interconnect structure can shorten the current path of the front and back circuits, reduce path loss during signal transmission, and at the same time, the metal conductor filling ensures good conductivity, laying the foundation for the stable operation of the attenuator in the radio frequency band.
[0037] Third, the chip-type RF attenuator disclosed in this utility model has excellent performance, simple manufacturing process, and high product reliability. Attached Figure Description
[0038] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0039] Figure 1 This is a front structural diagram of the chip radio frequency attenuator provided in an embodiment of the present invention.
[0040] Figure 2 This is a schematic diagram of the reverse side structure of the chip radio frequency attenuator provided in an embodiment of the present invention.
[0041] Wherein: 1-substrate, 21-first conductive strip, 22-second conductive strip, 23-third conductive strip, 24-fourth conductive strip, 31-signal input electrode, 32-signal output electrode, 33-working ground electrode, 331-lateral electrode portion, 332-vertical electrode portion, 41-first thick film resistor, 42-second thick film resistor, 43-third thick film resistor, 51-first via, 52-second via, 53-third via, 54-fourth via. Detailed Implementation
[0042] The preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings.
[0043] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0044] Using ordinal numbers such as “first,” “second,” “third,” etc. to describe ordinary objects merely indicates different instances of similar objects and is not intended to imply that the objects being described must have a given order in time, space, sequence, or any other way.
[0045] Furthermore, the expression "includes" is an "open-ended" expression, which means only that there is a corresponding component or step, and should not be interpreted as excluding additional components or steps.
[0046] To achieve the purpose of this utility model, some embodiments of a chip RF attenuator with a via interconnect structure, such as Figure 1-2 As shown, taking a 10dB chip-type RF attenuator as an example, it includes: an aluminum nitride ceramic substrate 1 with a rectangular block structure, a front conductor circuit and three thick film resistors disposed on the front side of the substrate 1, and a back conductor circuit disposed on the back side of the substrate 1.
[0047] The front conductor circuit includes: several conductive strips, which are distributed on the front side of the substrate 1 in a specific structure.
[0048] The reverse conductor circuit includes several conductive strips distributed on the reverse side of the substrate 1 according to a specific structure to form a signal input electrode 31, a signal output electrode 32, and a working ground electrode 33.
[0049] Four vias are provided on the substrate 1, extending through its thickness direction, and the vias are filled with metal conductors. The metal conductors in the vias can electrically connect the front conductor circuit and the back conductor circuit.
[0050] It is worth noting that there is no conductor structure connecting the front conductor circuit and the back conductor circuit around the perimeter of the substrate 1.
[0051] The aforementioned signal input electrode 31 and signal output electrode 32 are symmetrically distributed at the edge of the substrate 1 with the central axis of the width direction of the substrate 1 as the axis of symmetry.
[0052] The working electrode 33 has a T-shaped structure, which includes a transverse electrode portion 331 extending along the length direction of the substrate 1 and a longitudinal electrode portion 332 extending along the width direction of the substrate 1. The longitudinal electrode portion 332 is placed between the signal input electrode 31 and the signal output electrode 32, separating the signal input electrode 31 and the signal output electrode 32.
[0053] The T-shaped working ground electrode 33 separates the signal input electrode 31 and the signal output electrode 32 through the longitudinal electrode portion 332, which can effectively isolate crosstalk between the input and output signals. At the same time, the transverse electrode portion 331 extends along the length of the substrate 1, increasing the grounding area, reducing the grounding impedance, and enhancing the signal anti-interference capability.
[0054] The front conductor circuit specifically includes: a first conductor strip 21, a second conductor strip 22, a third conductor strip 23, and a fourth conductor strip 24.
[0055] The first conductive strip 21 extends along the length of the substrate 1 and corresponds to the distribution area of the transverse electrode portion 331 of the working ground electrode 33; the second conductive strip 22 is disposed at the center of the front side of the substrate 1 and corresponds to the distribution area of the longitudinal electrode portion 332 of the working ground electrode 33; the third conductive strip 23 corresponds to the distribution area of the signal input electrode 31; and the fourth conductive strip 24 corresponds to the distribution area of the signal output electrode 32.
[0056] The first to fourth conductors 24 of the front conductor circuit are respectively set to correspond to the transverse electrode part 331, the longitudinal electrode part 332 and the signal input and output electrodes of the reverse working ground electrode 33, forming a precise interconnection path, avoiding connection failure caused by circuit misalignment, and ensuring a clear and stable signal transmission path.
[0057] The second conductive strip 22 is disposed in the center of the front side of the substrate 1 and corresponds to the longitudinal electrode portion 332 of the working ground electrode 33. It provides a central connection point for the subsequent overlapping of thick film resistors, making the circuit structure more compact and reducing the distance loss of signal transmission between the conductive strips.
[0058] The three thick-film resistors disposed on the front side of the substrate 1 include: a first thick-film resistor 41, a second thick-film resistor 42, and a third thick-film resistor 43.
[0059] The two ends of the first thick film resistor 41 are electrically connected to the first conductive band 21 and the second conductive band 22, respectively; the two ends of the second thick film resistor 42 are electrically connected to the second conductive band 22 and the third conductive band 23, respectively; and the two ends of the third thick film resistor 43 are electrically connected to the second conductive band 22 and the fourth conductive band 24, respectively.
[0060] Three thick-film resistors are respectively connected between the first conductor 21 and the second conductor 22, the second conductor 22 and the third conductor 23, and the second conductor 22 and the fourth conductor 24 to form a "star" resistor connection structure. By adjusting the resistance value of one or more thick-film resistors, the attenuation value of the attenuator can be precisely controlled to meet the requirements of radio frequency signal conditioning.
[0061] The substrate 1 has four vias, specifically including: a first via 51, a second via 52, a third via 53, and a fourth via 54.
[0062] The first via 51 and the second via 52 are respectively disposed on two edges of the first conductive strip 21 near its length direction. The metal conductors filled in both vias are used to electrically connect the first conductive strip 21 to the lateral electrode portion 331 of the working ground electrode 33. The third via 53 is disposed in the corresponding area of the third conductive strip 23, and the metal conductor filled in it is used to electrically connect the third conductive strip 23 to the signal input electrode 31. The fourth via 54 is disposed in the corresponding area of the fourth conductive strip 24, and the metal conductor filled in it is used to electrically connect the fourth conductive strip 24 to the signal output electrode 32.
[0063] By adjusting the structure of the front conductor circuit on the front side of the substrate 1 and the resistance value of the thick film resistor, the attenuation value of the chip RF attenuator can be 10dB in the DC-6GHz operating frequency band, and the reflection coefficient at the input and output terminals can be greater than 20dB.
[0064] This utility model discloses a chip-type radio frequency attenuator with a via interconnection structure, which has the following beneficial effects:
[0065] First, it breaks through the structural limitations of traditional side conductors connecting the front and back circuits. By filling the vias of the substrate 1 with metal conductors, the electrical connection between the front and back conductor circuits is achieved, avoiding the problem of exposed side conductors being susceptible to environmental corrosion and damage, and greatly improving the stability and reliability of the circuit connection.
[0066] Secondly, the via interconnect structure can shorten the current path of the front and back circuits, reduce path loss during signal transmission, and at the same time, the metal conductor filling ensures good conductivity, laying the foundation for the stable operation of the attenuator in the radio frequency band.
[0067] Third, the chip-type RF attenuator disclosed in this utility model has excellent performance, simple manufacturing process, and high product reliability.
[0068] In order to further optimize the implementation effect of this utility model, in some other embodiments, the remaining features are the same, except that the first guide strip 21, the second guide strip 22, the third guide strip 23 and the fourth guide strip 24 are all widened at the positions where the through holes are provided, and the width of the widened part is greater than the width of other parts of the guide strip.
[0069] The preferred embodiments described above have the following advantages:
[0070] The guide belt is widened at the through-hole location to enhance the mechanical strength of the connection (tensile and shear resistance), prevent the guide belt around the through-hole from cracking and falling off due to stress concentration, and improve the long-term reliability of the product.
[0071] In order to further optimize the implementation effect of this utility model, in some other embodiments, the remaining features are the same, except that the cross-sections of the first through hole 51, the second through hole 52, the third through hole 53 and the fourth through hole 54 are all elliptical.
[0072] further,
[0073] The major axis of the elliptical cross-section of the first via 51 and the second via 52 is aligned with the length direction of the substrate 1.
[0074] The major axis of the elliptical cross-sections of the third via 53 and the fourth via 54 is aligned with the width direction of the substrate 1.
[0075] The preferred embodiments described above have the following advantages:
[0076] The elliptical structure is more easily adapted to the long strip shape of the conductor, reducing the risk of misalignment between the via and the conductor.
[0077] To further optimize the implementation effect of this utility model, in some other embodiments, the remaining features are the same, except that one or more layers of stacked dielectric protective layers are covered on the surface of the front conductor circuit and the thick film resistor.
[0078] The preferred embodiments described above have the following advantages:
[0079] One or more dielectric protective layers form a robust physical and chemical barrier, effectively protecting internal circuits and resistors from moisture, contaminants, mechanical scratches, and chemical corrosion, greatly enhancing the device's environmental durability and long-term stability. Stacked configurations allow for the use of composite layers of different materials to achieve even better protection.
[0080] In the description of this utility model, it should be understood that the terms "coaxial", "bottom", "one end", "top", "middle", "other end", "upper", "side", "top", "inner", "front", "center", "both ends", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0081] In this utility model, unless otherwise explicitly specified and limited, the terms "installation", "setting", "connection", "fixing", "screw connection", etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0082] The above embodiments are only for illustrating the technical concept and features of this utility model. Their purpose is to enable those skilled in the art to understand the content of this utility model and implement it. They should not be used to limit the protection scope of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be covered within the protection scope of this utility model.
Claims
1. A chip-type RF attenuator with via interconnect structure, including: A substrate, a front conductor circuit and a plurality of thick film resistors disposed on the front side of the substrate, and a back conductor circuit disposed on the back side of the substrate. The feature is that at least one via is provided on the substrate, extending through its thickness direction, and the via is filled with a metal conductor, wherein the metal conductor in the via can electrically connect the front conductor circuit and the back conductor circuit.
2. The chip-type RF attenuator according to claim 1, characterized in that, The substrate has a rectangular block structure.
3. The chip-type RF attenuator according to claim 2, characterized in that, The reverse conductor circuit includes: a plurality of conductive strips distributed on the reverse side of the substrate, forming a signal input electrode, a signal output electrode, and a working ground electrode; The signal input electrode and the signal output electrode are symmetrically distributed at the edge of the substrate with the central axis of the substrate in the width direction as the axis of symmetry. The working electrode has a T-shaped structure, which includes a transverse electrode portion extending along the length direction of the substrate and a longitudinal electrode portion extending along the width direction of the substrate. The longitudinal electrode portion is placed between the signal input electrode and the signal output electrode, separating the signal input electrode and the signal output electrode.
4. The chip-type RF attenuator according to claim 3, characterized in that, The front conductor circuit includes: The first conductive strip extends along the length direction of the substrate and corresponds to the distribution area of the transverse electrode portion of the working ground electrode. The second conductive strip is disposed at the center of the front side of the substrate and corresponds to the distribution area of the longitudinal electrode portion of the working ground electrode. The third conduction band corresponds to the distribution area of the signal input electrode; The fourth conduction band corresponds to the distribution area of the signal output electrode.
5. The chip-type RF attenuator according to claim 4, characterized in that, Three thick-film resistors are disposed on the front side of the substrate, including: The first thick film resistor has its two ends electrically connected to the first conductive band and the second conductive band, respectively; The second thick-film resistor has its two ends electrically connected to the second and third conductive bands, respectively; The third thick-film resistor has its two ends electrically connected to the second and fourth conductive bands, respectively.
6. The chip-type RF attenuator according to claim 5, characterized in that, The substrate has four vias, including: a first via, a second via, a third via, and a fourth via; The first via and the second via are respectively disposed on two edges of the first conductor near its length direction, and the metal conductors filled in both are used to electrically connect the first conductor to the transverse electrode portion of the working ground electrode. The third via is disposed in the corresponding area of the third conductor, and the metal conductor filled therein is used to electrically connect the third conductor and the signal input electrode; The fourth via is disposed in the corresponding area of the fourth conductor, and the metal conductor filled therein is used to electrically connect the fourth conductor to the signal output electrode.
7. The chip-type RF attenuator according to claim 6, characterized in that, The first, second, third, and fourth guide strips each have a widened portion at the location where a through hole is provided, and the width of the widened portion is greater than the width of the other parts of the guide strip in which it is located.
8. The chip-type RF attenuator according to claim 6, characterized in that, The cross-sections of the first via, the second via, the third via, and the fourth via are all elliptical.
9. The chip-type RF attenuator according to claim 8, characterized in that, The major axis of the elliptical cross-section of the first and second vias is aligned with the length direction of the substrate. The major axis of the elliptical cross-section of the third and fourth vias is aligned with the width direction of the substrate.
10. The chip-type RF attenuator according to any one of claims 1-9, characterized in that, One or more stacked dielectric protective layers are covered on the surface of the front conductor circuit and the thick film resistor.