KR20230024848A - Plastic package shell for isolator based on capacitor parallel connection and isolator - Google Patents

Abstract

The present invention discloses a plastic package shell for an isolator based on capacitor parallel connection and the isolator, which relate to the technical field of microwave components. The plastic package shell comprises pin metal parts (61), a carrier metal part (62), and a plastic part (63), wherein three capacitor ground pins having the same shape and size are provided on the carrier metal part (62), wherein the three capacitor ground pins are all bent inwards to form an accommodating cavity (62e) for accommodating an upper chip capacitor (8) and a lower chip capacitor (9), wherein the upper chip capacitor (8) and the lower chip capacitor (9) are vertically connected in parallel in the accommodating cavity (62e). Compared with traditional plastic package shell design, the present invention may improve port capacitance capacity, implement fully domestic manufacture of internal elements to manufacture lumped parameter circulators/isolators of 600 MHz to 700 MHz, reduce the size of a single capacitor, and increase the thickness of the single capacitor, thereby facilitating the manufacture of capacitors and reducing material costs of the manufacture of low-frequency devices.

Description

Plastic package shell and isolator for isolators based on parallel connection of capacitors

The present invention relates to the field of microwave component technology, and more particularly, to a plastic package shell for an isolator based on capacitor parallel connection and an isolator composed of the plastic package shell.

Currently, the 5G communication Sub6GHz frequency band ranges from 450MHz to 6GHz, which belongs to the field of low-frequency communication (compared to telecommunication, mm waves are referred to as high frequencies). Low-frequency communication has attracted the attention of telecommunication operators in various countries due to its long propagation distance and strong penetration capability. China Optoelectronics and China Mobile have accelerated the deployment of the 700 MHz frequency band, and Turkey's telecom operator TurkTelekom has launched N71 in 5G telecommunications. The application of the frequency band (617MHz ~ 698MHz) was explored, and the low-frequency communication base station device has a more urgent need for a lumped parameter isolator / isolator with miniaturization characteristics in the system.

At present, the structure of a conventional low-frequency lumped parameter irreversible magnetic element, that is, an isolator, is as shown in Fig. 1, mainly comprising an upper metal shell (1), a strontium constant magnet (2), a central conductor module (3), and a single-layer chip capacitor. (4), including a radio frequency resistor (5), a plastic package shell (6) and a lower metal shell (7); Here, the upper metal shell 1 and the lower metal shell 7 are both ferrous metal shells, providing a closed magnetic circuit to the element; The strontium constant magnet 2 provides an external constant magnetic field to the device; The central conductor module 3 is an irreversible junction of circuits, serving as energy circulation; The single-layer chip capacitor 4 and the center conductor module 3 constitute an LC circuit; RF resistor 5 provides a matched load of 50 ohms; The plastic package shell 6 provides a transmission path for signal transmission and at the same time serves as a carrier on which internal elements (including a single-layer chip capacitor 4 and a radio frequency resistor 5) are welded.

In the structure of the above conventional low frequency concentrated parameter isolator, the specific structure of its plastic package shell 6 is as shown in FIG. ); Here, the pin metal part 61 is two single pins (providing signal transmission), the carrier metal part 62 provides the ground and element welding mounting carrier location, and the plastic part 63 is a combination of two metal parts ( That is, the pin metal part 61 and the carrier metal part 62) provide a barrier to protect internal elements by providing a carrier.

The conventional plastic package shell capacitor mounting position is as shown in Figure 3, the size position of 2.2mm * 1mm and 3.3mm * 1mm in the drawing is the capacitor mounting position, and the maximum manufacturing size of the capacitor is 2.05mm * 0.95 mm.

The conventional plastic package shell mainly has the following problems.

The low-frequency concentration parameter irreversible magnetic element is designed so that the capacitor value increases as the frequency decreases, and the ceramic material of the current capacitor can only reach a dielectric constant of 140; For 758MHz ~ 803MHz lumped parameter isolator / isolator, the currently designed plastic package shell maximum capacitor mounting size is 2.1mm * 1mm, and the capacitor thickness must be about 0.1mm ~ 0.13mm to meet the design requirements of the capacitance value of the capacitor of 17PF ~ 22PF. can satisfy Due to the difficulty of research and development of high dielectric constant ceramic materials, when the manufacturing thickness of the capacitor is less than 0.16mm, the capacitance produced by the capacitor is very discrete and cannot be supplied in large quantities. Currently, mass production of low-frequency focused parameter isolators / circulators this cannot be implemented. Continuing to use the above conventional capacitor and plastic package shell design will cause great difficulties in designing a lumped parameter circulator/isolator of 600 MHz to 700 MHz used for subsequent communication.

An object of the present invention is to provide a plastic package shell for an isolator based on parallel connection of capacitors, to implement a lower frequency isolator design when both the plastic package shell size and the capacitor mounting size are fixed. It can be applied to circulator design.

In order to achieve the above object, the technical solutions used in the present invention are as follows. A plastic package shell for an isolator based on parallel connection of capacitors includes a pin metal part, a carrier metal part and a plastic part, wherein the carrier metal part has a first capacitor ground pin, a second capacitor ground pin and a third capacitor having the same shape and size. A ground pin is installed, and an intermediate ground plate is further installed, wherein the first capacitor ground pin and the intermediate ground plate are installed to face left and right, and the second capacitor ground pin and the third capacitor ground pin are installed to face left and right. The first capacitor ground pin, the second capacitor ground pin, and the third capacitor ground pin are all bent inward to form an accommodating cavity accommodating the upper chip capacitor and the lower chip capacitor, and the bottom of the accommodating cavity and the middle ground. The upper surfaces of the plates are at the same level.

As a preferred technical solution, the pin metal part and the carrier metal part are stamped and formed from phosphor bronze material and electroplated with nickel silver. Also preferred is C5191 phosphor bronze and a thickness of 0.13 mm is preferred. It can be ensured that the chip capacitors are welded tightly. One of ordinary skill in the art will understand that the present invention may be implemented using other grades of materials from which other previously known plastic package shell metal parts are made.

As a preferred technical solution, the plastic part is injection molded by LCP plastic, a more preferred grade of LCP plastic is E130i, and the plastic of this grade has good fluidity and relatively high strength after molding. A person skilled in the art will understand that the present invention may be implemented using other grades of materials from which other previously known plastic package shell plastic parts are made.

As a preferred technical solution, the upper width of the first capacitor ground pin, the second capacitor ground pin and the third capacitor ground pin is shorter than the width of the upper chip capacitor, more preferably 0.1 mm shorter, and under the design, the upper chip capacitor width is shorter. Capacitors do not easily cause solder shorts when welding.

As a preferred technical solution, the upper bending position width of the first capacitor ground pin, the second capacitor ground pin and the third capacitor ground pin is 0.3 mm to 0.4 mm.

Another object of the present invention is to provide an isolator made of the plastic package shell, and the technical solutions include an upper metal shell assembled in descending order, a strontium constant magnet, an upper chip capacitor, a central conductor module, a lower chip capacitor, and a radio frequency including a resistor, a plastic package shell and a lower metal shell; Here, the plastic package shell includes a pin metal part, a carrier metal part, and a plastic part, and a first capacitor ground pin, a second capacitor ground pin, and a third capacitor ground pin having the same shape and size are installed on the carrier metal part, , the first capacitor ground pin, the second capacitor ground pin, and the third capacitor ground pin are all inwardly bent to form an accommodating cavity, and the upper chip capacitor and the lower chip capacitor are vertically connected in parallel in the accommodating cavity.

Compared with the prior art, the advantages of the present invention are as follows, that is, compared to the conventional plastic package shell design, the present invention can improve the capacitance of the port and realize national production of internal elements, so that 600 MHz to 700 MHz It is possible to manufacture lumped parameter isolators/circulators, reduce the size of a single capacitor and increase the thickness of a single capacitor; It is advantageous for the manufacture of capacitors and reduces the material cost of manufacturing low-frequency devices.

1 is an exploded structural diagram of a conventional low frequency concentrated parameter isolator.
FIG. 2 is a structural schematic diagram of a plastic package shell in FIG. 1 .
FIG. 3 is a schematic view of a capacitor mounting position of a conventional plastic package shell in FIG. 2 .
4 is an exploded structural diagram of a low frequency concentration parameter isolator in an embodiment of the present invention.
5 is a structural schematic diagram of a plastic package shell in FIG. 1 .
6 is a schematic diagram of a parallel connection path of upper and lower capacitors of the isolator of the present invention.
7 is a schematic diagram of the plastic package shell production and input materials for the isolator of the present invention.
8 is a standing wave simulation curve of an input/output port of the isolator of the present invention.
9 is a simulation curve of the insertion loss of the isolator of the present invention.
10 is an isolation simulation curve of the isolator of the present invention.

Hereinafter, the present invention will be further described with reference to the accompanying drawings.

Example 1

Referring to FIG. 4, the low frequency concentration parameter isolator is assembled in descending order: an upper metal shell (1), a strontium constant magnet (2), an upper chip capacitor (8), a central conductor module (3), a lower chip capacitor (9), including a radio frequency resistor (5), a plastic package shell (6) and a lower metal shell (7);

Here, the structure of the plastic package shell 6 is as shown in Figs. 5 and 6, and two pin metal parts 61 (respectively an output port signal transmission pin 61a and an input port signal transmission pin 61b) ), a carrier metal part 62 and a plastic part 63, wherein the carrier metal part 62 has the same shape and size as the first capacitor ground pin 62a, the second capacitor ground pin 62b and A third capacitor ground pin 62c is installed, and an intermediate ground plate 62d is further installed, wherein the first capacitor ground pin 62a and the intermediate ground plate 62d are installed to face each other from side to side. The two capacitor ground pins 62b and the third capacitor ground pin 62c are installed to face each other from side to side, and the first capacitor ground pin 62a, the second capacitor ground pin 62b, and the third capacitor ground pin 62c ) are all bent inward to form an accommodating cavity 62e, and the upper chip capacitor 8 and the lower chip capacitor 9 are vertically connected in parallel in the accommodating cavity 62e, where the upper chip capacitor 8 ) and the lower chip capacitor 9, a center conductor transmission wire 10 is installed.

In this embodiment, the metal parts of the plastic package shell 6, namely the pin metal part 61 and the carrier metal part 62, are both stamped and molded with 0.13 mm thick C5191 phosphor bronze material and electroplated with nickel silver to form chips. Ensure capacitors are welded tightly.

In this embodiment, the plastic part 63 of the plastic package shell 6 is injection molded by LCP plastic of E130i, and the plastic of this grade has good fluidity and relatively high strength after molding.

In this embodiment, the upper width of the designed first capacitor ground pin 62a, the second capacitor ground pin 62b, and the third capacitor ground pin 62c of the plastic package shell 6 is the upper chip capacitor 8 0.1 mm shorter than the width of , and thus, under the above design, the upper layer chip capacitor 8 does not easily cause solder short circuit during welding.

Referring to FIG. 7 , the three capacitor ground pins (ie, the first capacitor ground pin 62a, the second capacitor ground pin 62b, and the third capacitor ground pin 62c) of the upper part of the plastic package shell 6 When the silver material flows in, the plastic part 63 is parallel to the sidewall and faces upward. When stamping and forming, the second half of the upper capacitor ground pin is punched and bent groove 62f, and the punched groove is a 60° triangular groove. It is designed to guarantee the width of the bending position to be 0.3 ~ 0.4mm, so that subsequent assembly and molding is easy.

Using the design of this embodiment, the capacitance of the pot capacitor of the designed plastic package shell is increased from the limiting capacity of 16 to 21PF of the conventional design of the plastic package shell to the limiting capacity of 20 to 32PF, and the size of the capacitor is 2.15 mm of the conventional design. *0.95mm is reduced from 1.5mm*0.95mm to 2.0mm*0.95mm, and the thickness of a single capacitor is increased from 0.12mm to 0.15mm in the conventional design to 0.17mm to 0.25mm, making capacitor manufacturing advantageous and low-frequency device manufacturing The capacitor material cost of can be reduced from 18 yuan to 20 yuan in the conventional design to 8 yuan to 12 yuan.

In this embodiment, the isolator was designed for 617 MHz to 652 MHz in the N71 frequency band in the 600 MHz to 700 MHz frequency band range, and the electrical performance curve results by simulation calculation are shown in FIGS. 8 to 10.

As can be seen from the figure, the simulation design of the product can reach a standing wave ratio of less than 1.4, an insertion loss of less than 0.6dB, and an isolation of less than 15dB. According to process experience, the product achieves standing wave ratio<1.8, insertion loss<1.1dB, and isolation>10dB at the final -40℃~125℃, which can meet the user's index requirements for the isolator in the frequency band.

The simulation designed capacitor capacitance values of the three ports of the 617MHz ~ 652MHz isolator are 22.83PF, 21.72PF, and 25.26PF, and according to the process experience and the difference between the simulation model and the actual assembly capacitance value, the final three The actual capacitance values of the port capacitors are 24PF to 25PF, 23PF to 24PF, and 27PF to 28PF.

According to the plastic package shell design of the present invention and the domestic chip capacitor manufacturing capability, capacitors with the following thickness and capacitance values can be selected to adapt to this type of isolator.

For the capacitance value of 24PF to 25PF, the size is L*W*T=2mm*0.91mm*0.17mm and the capacitance value is 13.25PF, and the size is L*W*T=1.8mm*0.9mm*0.18mm and the capacitance value is Requires to consist of two capacitors of 11.1 PF;

For the capacitance value of 23PF to 24PF, the size is L*W*T=2mm*0.91mm*0.17mm and the capacitance value is 13.25PF, and the size is L*W*T=1.8mm*0.9mm*0.19mm and the capacitance value is Requires to consist of two capacitors of 10.5 PF;

For the capacitance value of 27PF to 28PF, the size is L*W*T=3mm*0.9mm*0.25mm and the capacitance value is 13.4PF, and the size is L*W*T=2.5mm*0.9mm*0.2mm and the capacitance value is It requires that it consist of two capacitors of 13.9PF.

Example 2

In this embodiment, the upper width of the second capacitor ground pin 62b and the third capacitor ground pin 62c is 0.3 mm shorter than the width of the upper chip capacitor 8, and the rest is the same as in the first embodiment.

The above descriptions are only relatively preferred embodiments of the present invention, but do not limit the present invention, and any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should all fall within the protection scope of the present invention.

1: upper metal shell
2: strontium constant magnet
3: Center conductor module
4: single layer chip capacitor
5: radiofrequency resistance
6: plastic package shell
61: pin metal part
61a: output port signal transmission pin
61b: input port signal transmission pin
62: carrier metal part
62a: first capacitor ground pin
62b: second capacitor ground pin
62c: third capacitor ground pin
62d: middle ground plate
62e: receiving cavity
62f: punching and bending groove
63: plastic part
7: lower metal shell
8: upper layer chip capacitor
9: lower layer chip capacitor
10: center conductor transmission wire

Claims (8)

In the plastic package shell for isolators based on parallel connection of capacitors,
comprising a pin metal part 61, a carrier metal part 62 and a plastic part 63;
A first capacitor ground pin 62a, a second capacitor ground pin 62b, and a third capacitor ground pin 62c having the same shape and size are installed on the carrier metal part 62, and an intermediate ground plate 62d is Further, the first capacitor ground pin 62a and the intermediate ground plate 62d are installed to face left and right, and the second capacitor ground pin 62b and the third capacitor ground pin 62c are left and right to face each other. The first capacitor ground pin 62a, the second capacitor ground pin 62b, and the third capacitor ground pin 62c are all bent inward to form an upper chip capacitor 8 and a lower chip capacitor 9. A plastic package shell for an isolator based on capacitor parallel connection, characterized in that an accommodating cavity 62e is formed, and the bottom of the accommodating cavity 62e is at the same level as the upper surface of the intermediate ground plate 62d. According to claim 1,
The plastic package shell for an isolator based on capacitor parallel connection, characterized in that the pin metal part (61) and the carrier metal part (62) are stamped and molded with phosphor bronze material and electroplated with nickel silver. According to claim 2,
The phosphor bronze material is a plastic package shell for a capacitor parallel connection-based isolator, characterized in that the C5191 phosphor bronze material. According to claim 1,
The plastic part (63) is a plastic package shell for an isolator based on capacitor parallel connection, characterized in that the plastic part (63) is injection molded with LCP plastic. According to claim 4,
The plastic package shell for the capacitor parallel connection-based isolator, characterized in that the LCP plastic grade is E130i. According to claim 1,
The upper width of the first capacitor ground pin 62a, the second capacitor ground pin 62b, and the third capacitor ground pin 62c is shorter than the width of the upper chip capacitor 8. Plastic package shell for isolators. According to claim 1,
The first capacitor ground pin (62a), the second capacitor ground pin (62b), and the upper bending position width of the third capacitor ground pin (62c) are 0.3 mm to 0.4 mm for an isolator based on capacitor parallel connection, characterized in that plastic package shell. In the isolator made of the plastic package shell according to any one of claims 1 to 7,
Upper metal shell (1) assembled in descending order, strontium constant magnet (2), upper chip capacitor (8), center conductor module (3), lower chip capacitor (9), radio frequency resistor (5), plastic package shell ( 6) and a lower metal shell 7; The plastic package shell 6 includes a pin metal part 61, a carrier metal part 62 and a plastic part 63, and the carrier metal part 62 includes a first capacitor ground pin having the same shape and size ( 62a), a second capacitor ground pin 62b, and a third capacitor ground pin 62c are installed, and the first capacitor ground pin 62a, the second capacitor ground pin 62b, and the third capacitor ground pin 62c are installed. ) are all bent inward to form an accommodating cavity 62e, and the upper chip capacitor 8 and the lower chip capacitor 9 are vertically connected in parallel in the accommodating cavity 62e.

Images