JP7351983B2 - Plastic package housing for isolators and isolators based on capacitor parallel connection - Google Patents

Description

The present invention relates to the technical field of microwave components, and in particular to a plastic package housing for an isolator based on parallel connection of capacitors, and an isolator made of this plastic package housing.

The current Sub6GHz frequency band range for 5G communication is 450MHz to 6GHz, and belongs to the field of low frequency communication (in terms of communication, millimeter waves are called high frequency). Low frequency communication is favored by carriers in various countries due to its long transmission distance and strong penetration ability. China Broadcasting Corporation (CBN) and China Mobile Corporation (CMCC) are accelerating their deployment in the 700MHz frequency band, while Turkish operator TurkTelekom is expanding the N71 frequency band (617MHz to 698MHz) for 5G communications. I've been looking for ways to apply it. As a low frequency communication base station equipment, there is an urgent need for a lumped parameter isolator/isolator with the feature of miniaturization in the system.

At present, the isolator, which is a conventional low-frequency lumped constant non-reciprocal magnetic component, is configured as shown in FIG. 1, which mainly includes an upper metal housing 1, a strontium permanent magnet 2, a center conductor module 3, It includes a single layer chip capacitor 4, an RF resistor 5, a plastic package housing 6, and a lower metal housing 7. Here, the upper metal housing 1 and the lower metal housing 7 are both metal housings made of iron, and provide a closed magnetic circuit to the components. The strontium permanent magnet 2 provides an externally applied constant magnetic field to the component. The central conductor module 3 is a nonreciprocity junction of the circuit and functions for energy circulation. The single-layer chip capacitor 4 and the center conductor module 3 constitute an LC loop. RF resistor 5 provides a 50 ohm matched load. The plastic package housing 6 provides a transmission path for signal transmission and is a carrier for welding attachment of internal components (including a single layer chip capacitor 4 and an RF resistor 5).

In the structure of the above conventional low frequency lumped constant isolator, the plastic package housing 6 is specifically constructed as shown in FIG. Be prepared. Here, the pin metal parts 61 are two separate pins (which provide signal transmission). Carrier metal portion 62 provides a carrier location for grounding and welding attachment of the components. The plastic part 63 provides a carrier for the combination of the two metal parts (ie pin metal part 61 and carrier metal part 62) and provides a protective barrier for the internal components.

The mounting position of the capacitor in the conventional plastic package housing mentioned above is as shown in Figure 3. The maximum production size is 2.05mm*0.95mm.

The above conventional plastic package housings mainly have the following problems.
Low frequency lumped constant non-reciprocal magnetic components are designed such that the capacitance value increases with decreasing frequency, and currently capacitor ceramic materials can only achieve a dielectric constant of 140. For lumped constant isolators/isolation from 758MHz to 803MHz, we currently do not design plastic package housings such that the maximum capacitor mounting size is 2.1mm*1mm and the capacitor thickness is approximately 0.1mm to 0.13mm. Therefore, the design requirement for the capacitance value of 17PF to 22PF is not met. Because it is difficult to develop ceramic materials with a high dielectric constant, when manufacturing capacitors with a thickness of 0.16 mm or less, the capacitance of the manufactured capacitors becomes highly discrete, making it difficult to supply in large quantities, and currently, low frequency Mass production of lumped constant isolators/circulators becomes impossible. Continuing to employ the conventional capacitor and plastic package housing designs described above will make the design of 600 MHz to 700 MHz lumped constant circulators/isolators for subsequent communications very difficult.

It is an object of the present invention to provide a plastic package housing for an isolator based on a parallel connection of capacitors, so that when the size of the plastic package housing and the mounting size of the capacitors are constant, the design of isolators in lower frequency bands can be achieved. This is one of them. The invention may be applied to the design of low frequency band circulators.

In order to achieve the above object, the technical solution according to the present invention is as follows.
A plastic package housing for an isolator based on a capacitor parallel connection comprising a pin metal part, a carrier metal part and a plastic part, the carrier metal part having a first capacitor ground pin, a second capacitor ground pin of the same shape and size. A capacitor grounding pin, a third capacitor grounding pin, and an intermediate grounding plate are provided. The capacitor grounding pins are provided to face each other on the left and right, and the first capacitor grounding pin, the second capacitor grounding pin, and the third capacitor grounding pin are all bent inward to connect the upper layer chip capacitor and the lower layer chip capacitor. A plastic package housing for an isolator based on a capacitor parallel connection is formed, the bottom of said receiving chamber being aligned with the top surface of an intermediate ground plate.

In a preferred technical solution, the pin metal part and the carrier metal part are formed by pressing phosphor bronze material and electroplating with nickel silver. More preferably, C5191 phosphor bronze is used, preferably its thickness is 0.13 mm. This ensures that the chip capacitor can be firmly welded. It should be understood by those skilled in the art that the present invention can also be achieved by using known materials of other standards to make the metal portions of the plastic package housing.

In a preferred technical solution, the plastic part is injection molded with LCP plastic, and the standard of LCP plastic is preferably E130i. Plastics of this standard have good fluidity and strength after molding. It should be understood by those skilled in the art that the present invention can also be achieved by using known materials of other standards to make the plastic portions of the plastic package housing.

In a preferred technical solution, the first capacitor ground pin, the second capacitor ground pin and the third capacitor ground pin have upper widths shorter than the width of the upper layer chip capacitor, preferably by 0.1 mm. When the upper layer chip capacitor is designed in this way, solder short circuits are less likely to occur during welding.

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

Two of the objects of the present invention are to provide an isolator made by the above plastic package housing. The technical solution comprises an upper metal housing, a strontium permanent magnet, an upper chip capacitor, a center conductor module, a lower chip capacitor, an RF resistor, a plastic package housing, and a lower metal housing, which are assembled in order from top to bottom, and the plastic package The housing includes a pin metal portion, a carrier metal portion, and a plastic portion, and the carrier metal portion includes a first capacitor ground pin, a second capacitor ground pin, and a third capacitor ground pin having the same shape and size. The first capacitor ground pin, the second capacitor ground pin, and the third capacitor ground pin are all bent inward to form a housing chamber, and the upper layer chip capacitor and the lower layer chip capacitor are connected to each other. are connected vertically in parallel within the accommodation chamber.

The advantages of the present invention compared to the prior art are as follows. Compared to conventional plastic package housing designs, the present invention can improve port capacitance, achieve full domestic production of internal components such as 600-700 MHz lumped isolators/circulators, and reduce the size of a single capacitor. can be reduced, the thickness of a single capacitor can be increased, which can contribute to the fabrication of capacitors and reduce the cost of fabrication materials for low frequency components.

FIG. 1 is an exploded structural diagram of a conventional low frequency lumped constant isolator. FIG. 2 is a structural schematic diagram of the plastic package housing in FIG. 1. FIG. 3 is a schematic diagram of the mounting position of the capacitor of the conventional plastic package housing in FIG. 2. FIG. 4 is an exploded structural diagram of a low frequency lumped constant isolator according to an embodiment of the present invention. FIG. 5 is a schematic structural diagram of the plastic package housing in FIG. 1. FIG. 6 is a schematic diagram of the parallel paths of the upper and lower capacitors of the isolator according to the present invention. FIG. 7 is a schematic diagram of production and input of a plastic package housing for an isolator according to the present invention. FIG. 8 is a standing wave simulation curve for both input and output ports of the isolator according to the present invention. FIG. 9 is a simulation curve of isolator insertion loss according to the present invention. FIG. 10 is a simulation curve of isolation of an isolator according to the present invention.

The present invention will be further described below with reference to the accompanying drawings.

Example 1
As shown in FIG. 4, the low frequency lumped constant isolator includes an upper metal housing 1, a strontium permanent magnet 2, an upper layer chip capacitor 8, a center conductor module 3, a lower layer chip capacitor 9, and an RF resistor 5, which are assembled in order from top to bottom. , a plastic package housing 6, and a lower metal housing 7,

The plastic package housing 6 is configured as shown in FIGS. 5 and 6, and includes two pin metal parts (respectively an output port signal transmission pin 61a and an input port signal transmission pin 61b), a carrier metal part 62, and a plastic portion 63, and the carrier metal portion 62 includes a first capacitor grounding pin 62a, a second capacitor grounding pin 62b, and a third capacitor grounding pin 62c having the same shape and size, and an intermediate grounding plate 62d. The first capacitor grounding pin 62a and the intermediate grounding plate 62d are provided to face each other on the left and right, and the second capacitor grounding pin 62b and the third capacitor grounding pin 62c are provided on the left and right. The first capacitor grounding pin 62a, the second capacitor grounding pin 62b, and the third capacitor grounding pin 62c, which are provided facing each other, are all bent inward to form a housing chamber 62e, and the upper layer chip capacitor 8 and the lower layer chip capacitor 9 are vertically connected in parallel within the accommodation chamber 62e, and a center conductor transmission line 10 is provided between the upper layer chip capacitor 8 and the lower layer chip capacitor 9.

In this embodiment, the pin metal part 61 and the carrier metal part 62, which are the metal parts of the plastic package housing 6, are both pressed from C5191 phosphor bronze material with a thickness of 0.13 mm and electroplated with nickel silver. It is formed by This ensures that the chip capacitor can be firmly welded.

In this embodiment, the plastic part 63 of the plastic package housing 6 is injection molded from E130i LCP plastic. Plastics of this standard have good fluidity and strength after molding.

In this embodiment, the first capacitor grounding pin 62a, the second capacitor grounding pin 62b, and the third capacitor grounding pin 62c designed in the plastic package housing 6 have an upper width that is 0.1 mm wider than the width of the upper layer chip capacitor 8. Only short. When the upper layer chip capacitor is designed in this way, solder short circuits are less likely to occur during welding.

As shown in FIG. 7, the plastic package housing 6 has three capacitor grounding pins (i.e., a first capacitor grounding pin 62a, a second capacitor grounding pin 62b, and a third capacitor grounding pin) located at the top when input. 62c) extends upward and parallel to the side wall of the plastic portion 63, and a bending groove 62f is formed by punching the intended bending location of the upper capacitor ground pin during press molding. By adopting a 60° triangular groove design, the punching groove has a width of 0.3 to 0.4 mm at the bending position, which contributes to subsequent assembly and molding.

According to the design of this embodiment, the plastic package housing thus designed has a port capacitance increased from 16-21PF, which is the limiting capacity of the conventional plastic package housing design, to a limiting capacity of 20-32PF, The size of the capacitor is reduced from 2.15mm*0.95mm of the conventional design to 1.5mm*0.95mm~2.0mm*0.95mm, and the thickness of a single capacitor is reduced from 0.12mm*0.95mm of the conventional design. It can be increased from .15mm to 0.17mm-0.25mm. This contributes to the production of capacitors, and the cost of capacitor materials for manufacturing low frequency components can be reduced from 18 to 20 yuan for conventional designs to 8 to 12 yuan.

In this example, an isolator is designed for 617 MHz to 652 MHz in the N71 frequency band in the frequency band range of 600 MHz to 700 MHz. The electrical performance curve results of the simulation calculations are shown in FIGS. 8-10.

As can be seen from the drawing, the simulation design of a product of this standard can achieve a standing wave ratio of 1.4 or less, an insertion loss of 0.6 dB or less, and an isolation of 15 dB or less. According to process experience, products of this standard can ultimately achieve standing wave ratio <1.8, insertion loss <1.1 dB, and isolation >10 dB in the case of -40°C to 125°C. Meeting user's index requirements for frequency band isolators.

The simulated design capacitance values for the three ports of the 617 MHz to 652 MHz isolator are 22.83 PF, 21.72 PF, and 25.26 PF. Based on process experience and discrimination between simulation models and actual implemented capacitance values, the actual capacitance values of the three ports required by this standard isolator are ultimately 24PF to 25PF. , 23PF to 24PF, and 27PF to 28PF.

According to the design of the plastic package housing according to the present invention and the manufacturing ability of domestic chip capacitors, capacitors with the following thickness and capacitance values can be selected to meet the isolator of this standard.

Capacitors that require a capacitance value of 24PF to 25PF are capacitors whose size is L*W*T=2mm*0.91mm*0.17mm and whose capacitance value is 13.25PF, and capacitors whose size is L It consists of two capacitors: *W*T=1.8mm*0.9mm*0.18mm and a capacitor with a capacitance value of 11.1PF.

Capacitors that require a capacitance value of 23PF to 24PF are capacitors whose size is L*W*T=2mm*0.91mm*0.17mm and whose capacitance value is 13.25PF, and capacitors whose size is L It consists of two capacitors: *W*T=1.8mm*0.9mm*0.19mm and a capacitor with a capacitance of 10.5PF.

Capacitors that require a capacitance value of 27PF to 28PF are capacitors whose size is L*W*T=3mm*0.9mm*0.25mm and whose capacitance value is 13.4PF, and capacitors whose size is L It consists of two capacitors: *W*T=2.5mm*0.9mm*0.2mm and a capacitor with a capacitance value of 13.9PF.

Example 2
This embodiment is the same as the first embodiment except that the upper widths of the second capacitor grounding pin 62b and the third capacitor grounding pin 62c are shorter than the width of the upper layer chip capacitor 8 by 0.3 mm.

The above description is only a preferred embodiment of the invention and is not intended to limit the invention. All modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall fall within the protection scope of the present invention.

1 Upper metal housing, 2 Strontium permanent magnet, 3 Center conductor module, 4 Single layer chip capacitor, 5 RF resistor, 6 Plastic package housing, 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 Intermediate ground plate, 62e Accommodation chamber, 62f Bend groove, 63 Plastic part, 7 Lower metal housing, 8 Upper layer chip Capacitor, 9 Lower layer chip capacitor, 10 Center conductor transmission line.

Claims (8)

A plastic package housing for an isolator based on capacitor parallel connection, comprising a pin metal part (61), a carrier metal part (62) and a plastic part (63), comprising:
The carrier metal portion (62) includes a first capacitor grounding pin (62a), a second capacitor grounding pin (62b), and a third capacitor grounding pin (62c) having the same shape and size, and an intermediate grounding plate. (62d) and are provided,
The first capacitor grounding pin (62a) and the intermediate grounding plate (62d) are provided to face each other on the left and right, and the second capacitor grounding pin (62b) and the third capacitor grounding pin (62c) are provided on the left and right. Located opposite,
The first capacitor grounding pin (62a), the second capacitor grounding pin (62b), and the third capacitor grounding pin (62c) all extend upward from the edge of the carrier metal portion and are bent inward to connect to the upper layer. A housing chamber (62e) is formed to house the chip capacitor (8) and the lower layer chip capacitor (9),
The bottom of the accommodation chamber (62e) is aligned with the top surface of the intermediate ground plate (62d);
A plastic package housing for an isolator based on parallel connection of capacitors. The pin metal part (61) and the carrier metal part (62) are formed by pressing a phosphor bronze material and electroplating it with nickel silver.
A plastic package housing for an isolator based on parallel connection of capacitors according to claim 1. the phosphor bronze material is a C5191 phosphor bronze material;
A plastic package housing for an isolator based on parallel connection of capacitors according to claim 2. the plastic part (63) is injection molded from LCP plastic;
A plastic package housing for an isolator based on parallel connection of capacitors according to claim 1. The standard of the LCP plastic is E130i,
A plastic package housing for an isolator based on parallel connection of capacitors according to claim 4. The first capacitor grounding pin (62a), the second capacitor grounding pin (62b), and the third capacitor grounding pin (62c) have upper widths shorter than the width of the upper layer chip capacitor (8).
A plastic package housing for an isolator based on parallel connection of capacitors according to claim 1. The first capacitor ground pin (62a), the second capacitor ground pin (62b), and the third capacitor ground pin (62c) have a width of 0.3 mm to 0.4 mm at the upper bent position.
A plastic package housing for an isolator based on parallel connection of capacitors according to claim 1. An isolator made by a plastic package housing according to any one of claims 1 to 7, comprising:
Assembled in order from top to bottom: upper metal housing (1), strontium permanent magnet (2), upper layer chip capacitor (8), center conductor module (3), lower layer chip capacitor (9), RF resistor (5), plastic comprising a package housing (6) and a lower metal housing (7),
The upper layer chip capacitor (8) and the lower layer chip capacitor (9) are connected vertically in parallel within the accommodation chamber (62e).
An isolator characterized by: