JPH06318484A - Impedance matching connector - Google Patents

Abstract

PURPOSE:To match a high frequency propagation impedance and reconcile high frequency characteristic with prevention of thermal deformation by providing an insulator having a notch part formed between a contact receiver part and a lead part on the inside of an external conductor. CONSTITUTION:An impedance matching connector has an external conductor 1 and a notch 4 having an optional form in an optional position of an insulator 3 between a contact receiving part 2a for signal connection and a lead part 2b. A high frequency propagation impedance is matched to a prescribed value by regulating dielectric constant to an optional proper middle value with the dielectric constant of air. Thus, a liquid crystal polymer having a melting point higher than the melting point of a solder can be used as the insulator 3. Thus, the insulator 3 is never thermally deformed even when constituting related members including a F-plug are collectively soldered at once in a molten solder bath, and the downsizing of a builtup unit and a lower cost by efficient product can be attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impedance matching connector (hereinafter referred to as an F plug) used in a high frequency circuit unit such as a BS broadcast receiving tuner of a television receiver.

[0002]

2. Description of the Related Art A typical structure of a conventional F plug will be described with reference to FIGS.

In a circuit unit having an F plug 5 such as a tuner of a television receiver, the synthetic resin insulator 3 forming the F plug is prevented from being deformed by the heat of the molten solder bath 11. After the F connector 5 is screwed in advance above the shield case 6 with the screw 10 to complete the attachment, the electronic parts and the circuit board 8 already soldered are assembled, and the shield case 6 and It is general that the circuit board 8 is partially soldered individually.

Alternatively, when the constituent members are integrally assembled and then immersed in a molten solder bath at a predetermined depth for simultaneous soldering, flux and solder are prevented from adhering to the F connector 5. , The insulator 3 by the heat of the molten solder bath 11
It was necessary to mount the flux at a position considerably above the liquid surface of the flux and the molten solder bath 11 so as not to be thermally deformed.

[0005]

However, in the structure described above, when the circuit board 8 and the shield case 6 to which the F connector 5 is attached are simultaneously soldered, the influence of the heat of the molten solder bath is reduced. For this reason, the height of the shield case 6 needs to be larger than the outer diameter of the F-connector because the mounting position of the F-connector must be separated from the circuit board. Further, in order to immerse the F plug 5 in the molten solder bath 11 and solder the circuit board 8 at the same time, as the material of the insulator 3, the outer diameter dimension is regulated by JIS or the like, so that impedance matching is performed. In the case of using a synthetic resin having a suitable dielectric constant or dielectric power factor and a melting point lower than the temperature of the molten solder bath 11, which is generally used, the insulator is thermally deformed by the heat of the molten solder bath 11. There was a problem that caused it.

Therefore, when there is a concern about thermal deformation of the insulator 3, complicated processing steps and steps are required, such as soldering each constituent member such as a circuit board individually.

Even if a high melting point synthetic resin is applied to the material of the insulator 3, in most cases, the dielectric constant of polyethylene or the like having an appropriate dielectric constant of 2.3 to 2.4 is considerably increased. Due to the outer diameter size restriction of the F plug 5, the high-frequency input impedance does not match the predetermined value in the conventional shape of the insulator 3, and the voltage standing wave ratio (VSWR value; 1.2 or less), etc. It was difficult to satisfy the predetermined required characteristic specifications of.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an F plug which solves the above problems.

In order to solve the above-mentioned problems, the present invention uses a liquid crystal polymer, which is a synthetic resin having a melting point higher than that of solder, for the insulator of the F-connector, and devises its shape. This is the solution.

[0010]

The F plug of the present invention has the above structure and has a polyethylene dielectric constant of 2.3 to 2.
4 has a higher permittivity, and in the conventional insulator structure,
The high-frequency propagation impedance, which is slightly mismatched, is matched to achieve both high-frequency characteristics and thermal deformation prevention.

Further, the circuit boards using the above-mentioned F plugs can be collectively soldered.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The F plug structure of the present invention will be described below with reference to the drawings.

FIG. 1 (a) is a front sectional view of an F plug which is an embodiment of the present invention, and FIG. 1 (b) is a partial sectional view from the side. A cylindrical metal outer conductor 1 is provided outside the F plug 5.
Is formed, and a lead portion 2b corresponding to the output portion from the contact receiving portion 2a for connecting to the pin of the signal input plug is provided in the coaxial center portion inside thereof, and a predetermined arbitrary dielectric is provided between the contact receiving portion 2a and the lead portion 2b. The insulator 3 is made of a liquid crystal polymer having a melting point higher than that of the solder, and the insulator 3 is not thermally deformed even when immersed in a molten solder bath. On the other hand, however, the dielectric constant of the insulator may be as high as 3.6, and the high-frequency carrier impedance between the contact receiving portion 2a and the lead portion 2b may be slightly mismatched with the required electrical characteristics. I won't.

Therefore, in order to match the high frequency carrier impedance to a predetermined value, the insulator 3 between the external conductor portion 1 and the contact receiving portion 2a for signal connection to the lead portion 2b.
By providing an insulator 3 having a notch (space) 4 having an arbitrary shape at an arbitrary position of and adjusting the dielectric constant to an appropriate intermediate value with the dielectric constant of air 1, the high frequency propagation impedance can be adjusted. Matched the given value.

As a result, necessary electrical characteristics are satisfied, such as suppressing the voltage standing wave ratio (VSWR value) to 1.2 or less.

Next, referring to FIG. 2, the F plug 5 according to the present invention is used.
A state in which the shield case 6 and the circuit board 8 are integrally assembled is shown, and a state in which they are collectively soldered together will be described.

The F-connector 5 is caulked and attached to a zinc-tipped iron shield case 6 having a thickness of 0.6 t. Next, the F-connector 5 is covered with a protective cap 7 made of synthetic resin such as vinyl chloride for preventing flux and solder contamination, and the circuit board 8 is attached.
After being fitted to the shield case 6, the circuit board 8 is dipped to the tip surface of the jet bath 11 of flux and molten solder. After the immersion, soldering 9 is performed between the circuit board 8 and the shield case 6 or the lead portion 2b of the F connector 5.

As described above, in the F plug 5 according to the present embodiment, the soldering can be simultaneously performed at one time, so that the number of manufacturing steps can be reduced, and the same F as the circuit board 8 for connecting the F plug to the shield case 6. Since it can be positioned at the height, the shield case 6 can be downsized.

[0019]

According to the present invention, even if the F-connector is immersed in the flux or the molten solder bath with the shield case attached,
The F plug is released from thermal deformation of the insulator and the high frequency input impedance is matched to a predetermined value. As a result, the height of the shield case can be made almost equal to the width of the F plug even if the related members including the F plug are simultaneously soldered together, and the size of the assembly unit is greatly reduced. At the same time, cost reduction can be achieved as an efficient production method.

[Brief description of drawings]

FIG. 1 (a) is a sectional view of an F plug according to an embodiment of the present invention.

FIG. 2 is a diagram showing a state in which an F connector is attached according to an embodiment of the present invention.

FIG. 3 is a view showing a state in which a lower stopper is attached in a conventional example.

FIG. 4 is a partial cross-sectional view of a conventional structure of a conventional lower connector.

[Explanation of symbols]

 1 External Conductor Part 2a Center Contact Receiving Part 2b Lead Part 3 Insulator 4 Notch (Space) 5 F Plug Body 6 Shield Case 7 Protective Cap 8 Circuit Board 9 Soldering Part 10 Screwing Part 11 Molten Solder Jet Melt 12 Flux And molten solder bath immersion surface

Claims (2)

[Claims] 1. An impedance matching connector for use in a high frequency circuit unit, wherein an outer conductor to be joined to an outer plug is provided on the outer side, and a contact receiving portion to be joined to the outer plug and its lead are provided at the coaxial center portion of the outer conductor. And a cutout portion is formed between the contact receiving portion and the lead portion and the external conductor to join the high frequency input and the propagation impedance to a predetermined value. An impedance matching connector characterized by being provided with an insulator. 2. The impedance matching connector according to claim 1, the shield case, and the members such as a circuit board are collectively dipped into the molten solder bath surface to complete assembly and soldering of the members at the same time. And a method for mounting an impedance matching connector.