Small-size high-frequency band-pass surface-mounted crystal filter
By designing an embedded discrete structure of slots and mounting grooves on the PCB motherboard, the capacitor plate and crystal plate of a small-volume high-frequency bandpass surface-mount crystal filter can be replaced separately, solving the problems of dependence on imported high-end crystal filters and high maintenance costs of traditional filters, and meeting the requirements of miniaturization and reliability.
Patent Information
- Application Number
- CN202422412849.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-08
- Publication Date
- 2025-09-19
- Estimated Expiration
- 2034-10-08
AI Technical Summary
Existing high-end high-frequency surface-mount crystal filters rely on imports, with long procurement cycles. In addition, traditional crystal filters are prone to damage to PCB pads during component replacement and welding, increasing production and maintenance costs. At the same time, it is difficult to meet the requirements of miniaturization, chip-type and harsh environmental testing.
A small-volume high-frequency bandpass surface-mount crystal filter was designed. Slots, mounting slots, and positioning slots were set on the PCB mainboard. Mounting strips and shielding clips were used to realize the embedded discrete structure of the capacitor plate and the crystal plate, allowing the capacitor plate and the crystal plate to be replaced separately. The U-shaped plate and coil were combined for positioning and shielding, reducing the number of component soldering times and meeting the requirements of product miniaturization and reliability.
It is achieved that during the rework process, only the capacitor plate and crystal plate need to be replaced, which reduces production and maintenance costs, improves production efficiency, meets the requirements of product miniaturization and reliability in high overload environments, solves the high stopband attenuation problem of traditional filters, reduces production and maintenance costs, and improves product reliability.
Smart Images
Figure CN223364324U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of surface mounted crystal filters, and more specifically, to a small-volume high-frequency bandpass surface mounted crystal filter. Background Art
[0002] As the entire system develops rapidly towards integration, intelligence, lightweighting, and high reliability, the development of crystal filters is also forced to move towards miniaturization, chip-type, and surface mount technology. This has forced the development of surface mount technology to replace traditional pin-type crystal filters. Some high-end high-frequency surface mount crystal filters still rely on imports, with long procurement cycles. The development of miniature surface mount broadband piezoelectric filters is urgent.
[0003] In addition, the customer of the complete machine set high-quality and high-performance development goals. They not only had to ensure the development in the direction of miniaturization, chip-type, and surface mount, but also had to meet stringent environmental testing requirements, such as endurance vibration, random vibration, shock, acceleration and other external mechanical environmental tests. As a key component in the complete machine, the crystal filter's product structure became the focus of improving its reliability.
[0004] The interior of a crystal filter is generally composed of three major components: crystal, inductor, and capacitor. In traditional crystal filters, the crystal and capacitor components are soldered to the PCB assembly, and the PCB assembly is mounted on the filter metal base plate with pins.
[0005] Traditional crystal filter products are implemented using a single PCB board, and all components are soldered onto the entire PCB board. During product debugging, if internal component parameters do not meet requirements and need to be replaced, the operator requirements are extremely high. Especially when the product is returned for repair and component replacement, excessive component soldering will cause damage to the PCB pads, and the entire PCB circuit board must be replaced. Multiple component soldering will also cause component failure, especially surface mount components that cannot be repeatedly soldered and will only be scrapped, increasing production costs as well as debugging and maintenance costs. Utility Model Content
[0006] In order to overcome the above-mentioned defects of the prior art, the present invention provides a small-volume high-frequency bandpass surface-mounted crystal filter to solve the problems raised in the above-mentioned background technology.
[0007] To achieve the above objectives, the present invention provides the following technical solutions: a small-volume high-frequency bandpass surface-mount crystal filter, comprising a PCB mainboard, wherein a slot, a first mounting slot, a second mounting slot, and a third mounting slot are formed on the surface of the PCB mainboard, and a plurality of positioning slots are symmetrically formed around the PCB mainboard; a capacitor plate and a crystal plate are provided on the surface of the PCB mainboard, and a shielding clip is provided on the top of the crystal plate;
[0008] A U-shaped plate is provided at a position corresponding to the slot on the top of the PCB main board, a coil is provided in the middle of the U-shaped plate, a plurality of iron sheet crystals are welded and fixed on the surface of the crystal plate, the shielding clip, the capacitor plate and the bottom of the crystal plate are fixedly connected with a mounting bar, and a plurality of fixed capacitors and fine-tuning capacitors are welded and fixed on the surface of the capacitor plate.
[0009] Preferably, the slot hole and the third mounting slot are arranged on opposite sides of the first mounting slot and the second mounting slot, the first mounting slot is arranged on a side close to the slot hole, and there are multiple slot holes.
[0010] Preferably, the U-shaped plate is welded and fixed to the top of the slot hole, a coil slot hole is opened at the bottom of the U-shaped plate at a position corresponding to the slot hole, and the bottom end of the coil is located inside the coil slot hole.
[0011] Preferably, the crystal plate corresponds to the second mounting slot, the mounting bar at the bottom of the crystal plate is inserted into the second mounting slot, and the capacitor plate corresponds to the third mounting slot, the mounting bar at the bottom of the capacitor plate is inserted into the third mounting slot.
[0012] Preferably, the cross-sectional shape of the shielding clip is set to an "n" type structure, the shielding clip covers the top of the crystal plate, one end of the shielding clip corresponds to the first mounting groove, the bottom mounting bar of the shielding clip extends to the inside of the first mounting groove, and the shielding clip fits the outer shell of the iron sheet crystal.
[0013] Preferably, the bottom of the PCB main board is provided with leads, the bottoms of the mounting bars at the bottoms of the capacitor plate and the crystal plate are both provided with leads, and the bottom ends of the capacitor plate and the crystal plate are electrically connected.
[0014] Technical effects and advantages of this utility model:
[0015] The utility model first installs and fixes the capacitor plate and the crystal plate on the PCB main board by inserting the capacitor plate and the crystal plate into the third installation slot and the second installation slot through the installation bar, and then welds the fine-tuning capacitor and the fixed capacitor to the capacitor plate, and welds the iron crystal to the crystal plate. During the repair process, only the capacitor plate and the crystal plate need to be replaced, and the entire PCB main board does not need to be replaced, thereby reducing production costs and maintenance costs and improving production efficiency.
[0016] The utility model also meets the requirements of surface mounting and miniaturization of products by welding the capacitor to the surface of the capacitor plate and welding the crystal to the surface of the crystal plate. The shielding clip ensures effective shielding between the crystal sections, solves the problem of high resistance band attenuation in product miniaturization and improves the reliability of the product in high overload environment test projects. The embedded discrete structure is realized, and a special shielding design can be implemented for the internal space of the product, while meeting the requirements of surface mounting and miniaturization of the product.
[0017] In summary, through the mutual influence of the above-mentioned multiple effects, the capacitor plate and crystal plate can be replaced during the rework process without replacing the entire PCB mainboard, thereby reducing production and maintenance costs, improving production efficiency, and ensuring effective shielding between crystal nodes. This solves the problem of high resistance band attenuation in product miniaturization and the reliability of the product in high overload environment test projects, while meeting the surface mounting and miniaturization requirements of the product. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a schematic diagram of the overall structure of the utility model.
[0019] Figure 2 It is a side structural schematic diagram of the present utility model.
[0020] Figure 3 This is a schematic diagram of the top view of the PCB mainboard of the utility model.
[0021] Figure 4 This is a structural diagram of the crystal plate of the utility model.
[0022] Figure 5 This is a schematic diagram of the connection structure of the capacitor plates of the present invention.
[0023] The accompanying drawings are marked as follows: 1. PCB main board; 2. slot; 3. first mounting slot; 4. second mounting slot; 5. third mounting slot; 6. positioning slot; 7. capacitor plate; 8. crystal plate; 9. shielding clip; 10. U-shaped plate; 11. coil; 12. iron sheet crystal; 13. mounting bar; 14. fixed capacitor; 15. fine-tuning capacitor. DETAILED DESCRIPTION
[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 making creative efforts are within the scope of protection of the present invention.
[0025] As attached Figure 1-5The illustrated embodiment shows a small-volume, high-frequency, bandpass surface-mount crystal filter, comprising a PCB mainboard 1. A slot 2, a first mounting slot 3, a second mounting slot 4, and a third mounting slot 5 are provided on the surface of the PCB mainboard 1. The slot 2, the first mounting slot 3, the second mounting slot 4, and the third mounting slot 5 facilitate the installation and fixation of a coil 11, a capacitor plate 7, a crystal plate 8, and a shielding clamp 9. A plurality of positioning slots 6 are symmetrically provided around the periphery of the PCB mainboard 1 to facilitate positioning of the PCB mainboard 1. Capacitor plates 7 and crystal plates 8 are provided on the surface of the PCB mainboard 1. The capacitors can be welded and fixed to the surface of the capacitor plates 7, and the crystals can be welded and fixed to the surface of the crystal plates 8, thereby meeting the requirements of avoiding mounting and miniaturization of the product. A shielding clamp 9 is provided on the top of the crystal plate 8, and the shielding clamp 9 shields the crystal in the middle of the crystal plate 8, thereby solving the problem of high stop-band attenuation in miniaturized products and ensuring product reliability in high overload environment test projects.
[0026] A U-shaped plate 10 is provided at the position corresponding to the slot 2 on the top of the PCB main board 1, which is convenient for isolating and limiting the coil 11. The coil 11 is provided in the middle of the U-shaped plate 10. A plurality of iron sheet crystals 12 are welded and fixed on the surface of the crystal plate 8. The shielding clip 9 and the bottoms of the capacitor plate 7 and the crystal plate 8 are fixedly connected with a mounting bar 13. Through the cooperation of the mounting bar 13 and the first mounting slot 3, the second mounting slot 4, and the third mounting slot 5, the shielding clip 9 of the capacitor plate 7 and the crystal plate 8 can be conveniently inserted and installed on one side of the PCB main board 1 to realize an embedded discrete structure. A plurality of fixed capacitors 14 and fine-tuning capacitors 15 are welded and fixed on the surface of the capacitor plate 7. Through the special shielding design of the internal space of the product, the problem of high resistance band attenuation of the miniaturized product and the reliability of the product in the high overload environment test project are solved, while meeting the surface mounting and miniaturization requirements of the product.
[0027] As attached Figure 3 As shown, the slot 2 and the third mounting slot 5 are arranged on the opposite sides of the first mounting slot 3 and the second mounting slot 4. The first mounting slot 3 is arranged on the side close to the slot 2. There are multiple slots 2, which is convenient for locating and distinguishing the installation positions of the capacitor plate 7 and the crystal plate 8.
[0028] As attached Figure 1 、 2 As shown, the U-shaped plate 10 is welded and fixed to the top of the slot 2, and a coil slot is opened at the bottom of the U-shaped plate 10 at a position corresponding to the slot 2. The bottom end of the coil 11 is located inside the coil slot, and the coil 11 is limited and isolated by the U-shaped plate 10 to achieve effective shielding.
[0029] As attached Figure 1-4As shown, the crystal plate 8 corresponds to the second mounting groove 4, and the mounting bar 13 at the bottom of the crystal plate 8 is inserted into the interior of the second mounting groove 4. The capacitor plate 7 corresponds to the third mounting groove 5, and the mounting bar 13 at the bottom of the capacitor plate 7 is inserted into the interior of the third mounting groove 5. By inserting the mounting bar 13 into the corresponding second mounting groove 4 or third mounting groove 5, the installation position of the capacitor plate 7 and the crystal plate 8 can be limited, and the installation stability of the capacitor plate 7 and the crystal plate 8 can be improved.
[0030] As attached Figure 1 、 2 As shown, the cross-sectional shape of the shielding clamp 9 is set to an "n" type structure, the shielding clamp 9 covers the top of the crystal plate 8, one end of the shielding clamp 9 corresponds to the first mounting groove 3, and the bottom mounting bar 13 of the shielding clamp 9 extends to the inside of the first mounting groove 3. The shielding clamp 9 fits with the outer shell of the iron sheet crystal 12. The shielding clamp 9 is used to fit the outer shell of the iron sheet crystal 12, thereby achieving sufficient grounding of the shielding clamp 9 and the iron sheet crystal 12 through the shielding clamp 9, and ensuring effective shielding between the crystal nodes through the shielding clamp 9.
[0031] As attached Figure 1 、 2 As shown, a lead is provided at the bottom of the PCB mainboard 1, and a lead is provided at the bottom of the mounting bar 13 at the bottom of the capacitor plate 7 and the crystal plate 8. The bottom ends of the capacitor plate 7 and the crystal plate 8 are electrically connected. A lead is provided at the bottom of the PCB crystal vertical plate, and the lead is connected to the capacitor vertical plate through the slot of the PCB mainboard. The wire realizes the electrical connection between the capacitor plate 7 and the crystal plate 8 through the bottom layer of the PCB mainboard 1, which not only saves internal space, but also allows components to be soldered on the surface of the capacitor plate 7 and the crystal plate 8, avoiding the flying wire mode inside the traditional filter and improving the use effect.
[0032] The working principle of the utility model is as follows: when in use, the fine-tuning capacitor 15 and the fixed capacitor 14 are welded and fixed on the capacitor plate 7 and the iron crystal 12 is welded and fixed on the crystal plate 8. Then, the bottom mounting bar 13 of the crystal plate 8 is inserted into the inside of the second mounting groove 4, and the bottom mounting bar 13 of the capacitor plate 7 is inserted into the inside of the third mounting groove 5. Then, the crystal plate 8 and the capacitor plate 7 can be assembled and limited on the PCB mainboard 1 and welded and fixed;
[0033] Then, the shielding clip 9 is placed on the top of the crystal plate 8, and the mounting bar 13 on one side of the bottom end of the shielding clip 9 is inserted into the inside of the first mounting groove 3 to fix the shielding clip 9 and make the wall of the shielding clip 9 fit with the shell of the iron sheet crystal 12. The shielding clip 9 shields the iron sheet crystal 12 to improve the shielding effect.
[0034] When the fine-tuning capacitor 15 and the iron crystal 12 are damaged during the welding process, only the capacitor plate 7 or the crystal plate 8 needs to be replaced, which reduces the maintenance cost and avoids component failure;
[0035] Leads are set at the bottom of the PCB crystal vertical plate, and the leads are connected to the capacitor vertical plate through the slots of the PCB main board. The wires pass through the bottom layer of the PCB main board 1 to realize the electrical connection between the capacitor plate 7 and the crystal plate 8, which not only saves internal space but also allows components to be soldered on the surface of the capacitor plate 7 and the crystal plate 8, avoiding the flying wire mode inside the traditional filter and improving the use effect.
[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A small-volume high-frequency bandpass surface-mount crystal filter, comprising a PCB motherboard (1), characterized in that: The surface of the PCB mainboard (1) is provided with a slot hole (2), a first mounting slot (3), a second mounting slot (4), and a third mounting slot (5); a plurality of positioning slots (6) are symmetrically provided around the periphery of the PCB mainboard (1); a capacitor plate (7) and a crystal plate (8) are provided on the surface of the PCB mainboard (1); a shielding clip (9) is provided on the top of the crystal plate (8); A U-shaped plate (10) is provided at a position on the top of the PCB mainboard (1) corresponding to the slot hole (2), a coil (11) is provided in the middle of the U-shaped plate (10), a plurality of iron crystals (12) are welded and fixed to the surface of the crystal plate (8), the shielding clip (9) and the capacitor plate (7) and the bottom of the crystal plate (8) are fixedly connected with a mounting bar (13), and a plurality of fixed capacitors (14) and fine-tuning capacitors (15) are welded and fixed to the surface of the capacitor plate (7).
2. The small-volume high-frequency bandpass surface-mount crystal filter according to claim 1, characterized in that: The slot hole (2) and the third mounting slot (5) are arranged on opposite sides of the first mounting slot (3) and the second mounting slot (4); the first mounting slot (3) is arranged on a side close to the slot hole (2); and there are a plurality of slot holes (2).
3. The small-volume high-frequency bandpass surface-mount crystal filter according to claim 1, characterized in that: The U-shaped plate (10) is welded and fixed to the top of the slot hole (2); a coil slot hole is provided at the bottom of the U-shaped plate (10) at a position corresponding to the slot hole (2); and the bottom end of the coil (11) is located inside the coil slot hole.
4. The small-volume high-frequency bandpass surface-mount crystal filter according to claim 1, characterized in that: The crystal plate (8) corresponds to the second mounting groove (4), and the mounting bar (13) at the bottom of the crystal plate (8) is inserted into the interior of the second mounting groove (4); the capacitor plate (7) corresponds to the third mounting groove (5), and the mounting bar (13) at the bottom of the capacitor plate (7) is inserted into the interior of the third mounting groove (5).
5. The small-volume high-frequency bandpass surface-mount crystal filter according to claim 1, characterized in that: The cross-sectional shape of the shielding clip (9) is set to an "n"-shaped structure. The shielding clip (9) covers the top of the crystal plate (8). One end of the shielding clip (9) corresponds to the first mounting groove (3). The bottom mounting bar (13) of the shielding clip (9) extends to the inside of the first mounting groove (3). The shielding clip (9) fits the outer shell of the iron sheet crystal (12).
6. The small-volume high-frequency bandpass surface-mount crystal filter according to claim 1, characterized in that: The bottom of the PCB mainboard (1) is provided with a lead, and the bottoms of the mounting bars (13) at the bottoms of the capacitor plate (7) and the crystal plate (8) are both provided with a lead, and the bottom ends of the capacitor plate (7) and the crystal plate (8) are electrically connected.