CN210041769U

CN210041769U - LTCC organic hybrid filter

Info

Publication number: CN210041769U
Application number: CN201920392524.8U
Authority: CN
Inventors: 何泽涛
Original assignee: Chengdu Hongke Electronic Technology Co Ltd
Current assignee: Chengdu Hongke Electronic Technology Co Ltd
Priority date: 2019-03-26
Filing date: 2019-03-26
Publication date: 2020-02-07
Anticipated expiration: 2029-03-26

Abstract

The utility model discloses an organic hybrid filter of LTCC, including LTCC base plate, electric capacity and inductance, electric capacity integrate in the inside of LTCC base plate, the inductance install in the surface of LTCC base plate. The surface of LTCC base plate is provided with the pad with LTCC base plate internal circuit intercommunication, the inductance is the coil inductance, the both ends of coil inductance respectively with two the pad is connected. The LTCC substrate surface is provided with a resin protection layer, and the coil inductor is wrapped in the resin protection layer. The utility model discloses an assemble the inductance on the surface of LTCC base plate, rather than integrated inside the LTCC base plate, improved the Q value of inductance for the filter loss is little, and frequency selectivity is high.

Description

LTCC organic hybrid filter

Technical Field

The utility model belongs to the technical field of the wave filter, concretely relates to modified LTCC wave filter.

Background

The existing filters are more in types, but have some defects. The dielectric filter is large (especially the height is difficult to be lower than 5mm) and the bandwidth is limited (less than 10 percent); the chip filter has the problems of difficult realization of large capacitance value, low Q value of an on-chip inductor and high loss and low selectivity, and is only suitable for the requirements of the filter of a microwave frequency band. This makes it difficult to select a miniaturized filter for the radio frequency band, especially for a highly reliable thin product suitable for airborne applications. To accommodate onboard or satellite-borne applications, component designs tend to be miniaturized and thinned. The traditional filter becomes the bottleneck of the process, especially for the most applied low frequency band (ultrashort wave, radio frequency band), the larger element value makes the LC filter and LTCC filter the only possible implementation methods, but the respective disadvantages make the LC filter and LTCC filter unable to fully satisfy the application requirements.

The traditional monolithic chip type LTCC filter has large loss (generally 3.5dB-5dB) in a radio frequency band, low selectivity and large influence of parasitic coupling, and has the defects that the out-of-band rejection is difficult to improve and a parasitic pass band (30dBc) exists. The LTCC filter is compact in structure and small in size, is the leading edge of the existing radio frequency passive device, but is limited by factors such as unsatisfactory conductive performance of a printed conductor, large parasitic capacitance and the like, the Q value (quality factor) of the existing LTCC filter is not high, the transition characteristic is unsatisfactory, the loss of the edge of a frequency band is large, the out-of-band rejection is unsatisfactory, a strong parasitic passband exists, and the applicable frequency band or the bandwidth is limited.

SUMMERY OF THE UTILITY MODEL

Under the above background, the inventor proposes a technical scheme combining the advantages of both LC filters and LTCC filters, and provides an LTCC organic hybrid filter. Limited to process implementation and market goals, traditional manufacturers have not thought to solve the problem in this way, but application goals are always present, which compels the inventors to make changes and innovations. The significance of the method lies in that the bottleneck of miniaturization of the design of the existing radio transceiving (mainly in the receiving field) component is solved, a mode which has excellent performance and high reliability and is suitable for batch production is provided, and the realization of a miniaturized radio system can be promoted.

The utility model provides an organic hybrid filter of LTCC has solved the big, unsatisfactory, the applicable frequency channel of transition characteristic or the limited problem of bandwidth of LTCC wave filter frequency band loss.

The utility model adopts the technical proposal that: the utility model provides an organic hybrid filter of LTCC, includes LTCC base plate, electric capacity and inductance, the electric capacity integrate in the inside of LTCC base plate, the inductance install in the surface of LTCC base plate.

Further, the surface of LTCC base plate is provided with the pad that communicates with LTCC base plate internal circuit, the inductance is the coil inductance, the both ends of coil inductance respectively with two the pad is connected.

Furthermore, a resin protection layer is arranged on the surface of the LTCC substrate, and the coil inductor is wrapped in the resin protection layer.

Further, the coil inductance is a coil inductance containing a ferrite core.

Furthermore, the inductor is a chip winding inductor, a resin protective layer is arranged on the surface of the LTCC substrate, and the chip winding inductor is wrapped in the resin protective layer.

Further, the resin protective layer is composed of a thermosetting resin.

Further, the LTCC substrate is provided with a plurality of layers.

Furthermore, a surface-mounted pad type interface is arranged on the surface mounting surface of the LTCC substrate.

Since the technical scheme is used, the beneficial effects of the utility model are that:

the utility model discloses an assemble the inductance on the surface of LTCC base plate, rather than integrated inside the LTCC base plate, improved the Q value of inductance for the filter loss is little, and frequency selectivity is high. The utility model discloses compromise the advantage of LTCC technique and LC wave filter, had thin shape, small light in weight, loss low, selectivity high, the good reliability characteristics.

Drawings

Fig. 1 to 3 are schematic structural views of embodiment 1 of the present invention;

FIG. 4 is a schematic structural view of a resin protective layer according to the present invention;

fig. 5 is a perspective cross-sectional view of embodiment 1 of the present invention;

fig. 6 is the actual measurement curve chart of the present invention.

Reference numerals: the circuit comprises a 1-LTCC substrate, a 2-coil inductor, a 3-bonding pad, a 4-resin protective layer and a 5-surface-mounted bonding pad type interface.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", and the like indicate the position or positional relationship based on the position or positional relationship shown in the drawings, or the position or positional relationship which is usually placed when the utility model is used, and are only for convenience of description and simplification of the description, but do not indicate or imply that the device or element to be referred must have a specific position, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

Example 1

Referring to fig. 1 to 4, an LTCC organic hybrid filter includes an LTCC substrate 1, a capacitor integrated in the LTCC substrate 1, and an inductor installed on a surface of the LTCC substrate 1. The surface of LTCC base plate 1 is provided with the pad 3 with 1 internal circuit intercommunication of LTCC base plate, the inductance is coil inductance 2, the both ends of coil inductance 2 respectively with two pad 3 is connected. The surface of the LTCC substrate 1 is provided with a plurality of bonding pads 3, two ends of the coil inductor 2 are respectively provided with a pin, and each pin of the coil inductor 2 is welded corresponding to one bonding pad 3, namely, each coil inductor 2 is welded corresponding to two bonding pads 3. The surface of the LTCC substrate 1 is provided with a resin protection layer 4, and the coil inductor 2 is wrapped in the resin protection layer 4. The hardened resin plays a role in fixing and protecting the coil inductor 2 on the surface of the LTCC substrate 1, the coil inductor 2 is encapsulated by the resin, cannot shake due to external force, is not easy to deform due to compression, is not easy to damage and can prolong the service life. The resin protective layer 4 is made of thermosetting resin, the thermosetting resin is heated to generate chemical change, is gradually hardened and formed, is not softened and dissolved after being heated again, and improves the stability.

And a capacitor and a circuit which are integrated in the LTCC substrate 1 and a coil inductor on the surface of the LTCC substrate 1 form a filter circuit. It should be noted that the components in the present invention can be designed according to actual needs, and the number of components such as capacitors and inductors can be customized according to actual needs, and is not limited to the content shown in the drawings. As shown in fig. 5, the LTCC substrate 1 is provided with multiple layers, and the number of the layers of the LTCC substrate 1 may be 5 to 20, which can be customized according to actual needs. When the LTCC substrate is installed on the PCB, the contact surface of the LTCC substrate and the PCB is a surface mounting surface, the surface mounting surface of the LTCC substrate is provided with six surface mounting pad type interfaces 5, four of the surface mounting pad type interfaces 5 are grounding ports, one is an input port, and the other is an output port.

In this embodiment, the coil inductor 2 is an air-core coil inductor. As another embodiment, the coil inductor 2 may be a coil inductor (not shown in the drawings) including a ferrite core, and the coil inductor including the ferrite core has a small loss and a large inductance.

In another embodiment, the inductor may be a chip-type wire-wound inductor (not shown in the drawings), a resin protective layer 4 is disposed on the surface of the LTCC substrate 1, and the chip-type wire-wound inductor is wrapped in the resin protective layer 4. The chip type winding inductor has simple manufacturing process and low cost, and can reduce the overall manufacturing cost of the LTCC filter.

In the prior art, the LTCC filter manufacturing process is as follows:

firstly, punching holes on an LTCC green ceramic film tape and filling metal slurry, and then printing patterns representing a capacitor and an inductor on the LTCC green ceramic film tape by using the metal slurry;

secondly, overlapping the LTCC green ceramic membrane belts printed with patterns in sequence, and then connecting different green ceramic membrane belts through holes filled with metal slurry;

thirdly, the stacked green ceramic film belt layer is subjected to static pressure, dicing and sintering to form a semi-finished product of the cooked porcelain;

and fourthly, coating metal slurry on the lead-out electrode on the side surface of the LTCC semi-finished product and sintering.

The inventors have found that with the LTCC filter manufactured by the above prior art, the limited conductivity of the metal limits the Q value of the inductor, since the inductor is printed inside the LTCC ceramic body by fine lines. This results in large LTCC filter losses and a less steep transition band.

The utility model discloses arrange the inductance in LTCC base plate 1 surface, rather than unify and integrate in inside, prior art has increased the conductivity of inductance relatively for LTCC filter's Q value is higher. The Q value of the inductor is improved as the main factor influencing the loss, so that the loss of the filter is smaller, and higher frequency selectivity can be realized.

Actually measured, the actually measured curve of the LTCC organic hybrid filter is shown in fig. 6, under the out-of-band suppression condition, the insertion loss IL of the LTCC organic hybrid filter is below 1.5dB, and the voltage standing wave ratio VSWR is below 1.3, and the result shows that the loss of the LTCC organic hybrid filter is far lower than that of the existing LTCC filter.

In the prior art, if the process parameters of the LTCC filter are changed in the manufacturing process, the whole batch of products can be scrapped. The utility model provides an organic hybrid filter of LTCC is debuggable in manufacturing process, electroplates the pad on its surface after LTCC base plate sintering is accomplished, then welding inductance to pad, debugs, encapsulates again, if technological parameter changes, the accessible changes inductance coil's density and adjusts filtering parameter, encapsulates again after performance parameter is up to standard, has improved the yield of production greatly. The development cost of the LTCC filter is reduced to a certain extent, the risk of repeated edition opening is reduced, and therefore the LTCC filter has practical value, can exert advantages in a miniaturized microwave assembly and is used for microwave frequency conversion assemblies, receivers, power amplifier equipment and the like.

Claims

1. The utility model provides an organic hybrid filter of LTCC, includes LTCC base plate, electric capacity and inductance, its characterized in that: the capacitor is integrated inside the LTCC substrate, and the inductor is installed on the surface of the LTCC substrate.

2. The LTCC organic hybrid filter of claim 1, wherein: the surface of LTCC base plate is provided with the pad with LTCC base plate internal circuit intercommunication, the inductance is the coil inductance, the both ends of coil inductance respectively with two the pad is connected.

3. The LTCC organic hybrid filter of claim 2, wherein: the LTCC substrate surface is provided with a resin protection layer, and the coil inductor is wrapped in the resin protection layer.

4. The LTCC organic hybrid filter of claim 3, wherein: the coil inductance is a coil inductance containing a ferrite core.

5. The LTCC organic hybrid filter of claim 1, wherein: the inductor is a chip winding inductor, a resin protective layer is arranged on the surface of the LTCC substrate, and the chip winding inductor is coated in the resin protective layer.

6. An LTCC organic hybrid filter according to any of claims 3 to 5, wherein: the resin protective layer is composed of a thermosetting resin.

7. An LTCC organic hybrid filter according to any of claims 1 to 5, wherein: the LTCC substrate is provided with a plurality of layers.

8. The LTCC organic hybrid filter of claim 7, wherein: and the surface mounting surface of the LTCC substrate is provided with a surface mounting pad type interface.