JPS5819877Y2 - Tuner device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a tuner device for a television receiver or the like.

Varactor using a variable capacitance diode as a tuning element
In a thick film hybrid type tuner device, as shown in FIGS. 1 and 2, a pin 3 for supplying a power supply voltage and other wrapper pins 4 are formed in a plate 2 forming a shield container 1. 13 and 14 to serve as terminals for connecting the inside and outside of the tuner device, the positions of these pins 3 and 4 are restricted by an insulating plate 5 so that they do not come into contact with the plate 2, and the pins 3 and 4 are is formed in advance to have an L-shaped portion inside the container 1, and the tip of this L-shaped portion is passed through the holes 7 and 8 formed in the ceramic substrate 6, and soldered 9 is attached to the pin 3. , 4 to form a thick film capacitor 10 with a high dielectric constant to prevent high frequency signals from leaking to the outside through L7.

That is, a coil 11, a discrete capacitor 12, etc. are attached to the ceramic substrate 6, and the soldering on the side opposite to the surface 6b on which these electronic components are attached is formed between the electrode layer 15 and the electrode layer 16 on the surface 6a. A thick film capacitor 10 with a high dielectric constant is formed by a dielectric layer 11 with a high dielectric constant and protective film layers 18 and 19 mainly composed of a material with excellent moisture resistance. is connected to pin 3 and said plate 2 (which is held at ground potential) by means of a thick film capacitor 10 to bypass the high frequency signal to the ground point.

It should be noted that this configuration has been adopted not only for the power supply voltage supply pin 3 but also for other wrapper pins 4 as needed.

By the way, the thick film capacitor 10 has a frequency characteristic of V
At relatively low frequencies such as HF, it has a capacitance value of about 1000 pF and serves as a high frequency removal filter, but at higher frequencies of UHF, that is, frequencies of several hundred MHz or more, it acts more as an inductance than as a capacitance. It tends to be difficult to achieve the intended purpose.

For this reason, it is possible to form a capacitor using another ceramic substrate instead of one of the through holes 13 and 14 of the plate 2, but adding another ceramic substrate in this way increases the thickness of the ceramic substrate 6 as the circuit board. The significance of forming the membrane capacitor 10 is significantly lost and it is not appropriate.

In view of this, the present invention proposes a tuner device devised to take advantage of the significance of the thick film capacitor and compensate for the drawbacks in the high frequency range as described above. details.

In FIGS. 3 to 5, in which the present invention is implemented, the same parts as in FIGS. 1 and 2 are given the same symbols for convenience of explanation.

The key features of the present invention are that an electrode layer 16 and a high dielectric constant dielectric layer 1 are provided on the soldering surface 6a of the ceramic substrate 6.
7, and a counter electrode layer 15 and protective film layers 18 and 19 thereon.
A thick film capacitor 10 with a high dielectric constant is formed by forming the thick film capacitor 10 with a high dielectric constant, and an electrode layer 21 is provided on the other surface 6b of the ceramic substrate 6 corresponding to the electrode layer 16 of the thick film capacitor 10, that is, the surface on the component mounting side. 16, 21 and ceramic substrate 6
Therefore, a small capacity auxiliary capacitor 22 is provided electrically in parallel with the high dielectric constant thick film capacitor 10.

If the ceramic substrate is a ceramic substrate containing 0.6% aluminum and its thickness is in the order of Q, 8, the electrode layer 1
6, 21 is the material of Baladylum silver thread (DuPont Co. 9
061), approximately 0.2 pF/7 per unit area
capacity is obtained.

When the electrode layer 21 is grounded, the hot side electrode layer 16 is made in contact with the substrate 6 to form the thick film capacitor 10 as shown in FIG. 4, and the ground side electrode layer 15 is placed on top. As a result, the area of the auxiliary capacitor 22 facing the electrodes can be increased as shown by diagonal lines A and B in FIG. 5, and since this capacitance is several pF, it functions as an extremely good high frequency removal filter.

If the ground side electrode layer 15 is brought into contact with the substrate 6 and the hot side electrode layer 16 is provided thereon as in the thick film capacitor 10 shown in FIG. capacity will be reduced.

Note that in FIG. 5, part B also shows the part of the high dielectric constant thick film capacitor 10.

The auxiliary capacitor 22 may be formed on the ceramic substrate 6 only at a position corresponding to the high dielectric constant thick film capacitor 10, that is, only at a portion B. However, as shown in A in FIG. It was confirmed that the high frequency removal effect is good when the pin 3 is formed to have a diameter smaller than 1, regardless of the length of the parallel portion of the pin 3 with the ceramic substrate 6.

It goes without saying that the electrode layer 21 forming the auxiliary capacitor 22 is soldered 23 to the plate 2.

As mentioned above, according to the present invention, the high frequency signal removal effect is suitably performed even in the high frequency band of the reception frequency of the tuner, so that it is extremely effective.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the main parts of a conventional tuner device.
The figure is an enlarged sectional view of the main part. FIG. 3 is a perspective view of a main part of a tuner device embodying the present invention, FIG. 4 is a sectional view showing the main part in an enlarged manner, and FIG. 5 is an explanatory view thereof. 1... Shield container, 2... Plate, 3... Power voltage supply pin, 6...
Ceramic board, 6a...Soldering is on the surface, 6b...
...Component mounting surface (other side), 9...Solder,
10...High dielectric constant thick film capacitor, 16.2
1... Electrode.

Claims (1)

[Scope of utility model registration request] A pin for supplying DC voltage to a tuner circuit built into the shield container is passed through a hole provided in a circuit board disposed in the container and soldered thereto, and a button is attached to the soldering side surface. In a tuner device in which a thick film capacitor for high frequency removal is formed between a part and a container, the soldering is performed by connecting an electrode provided on the substrate surface for forming the thick film capacitor, the substrate, and the substrate. A tuner device characterized in that an auxiliary capacitor is formed electrically in parallel with the thick film capacitor by an electrode provided on the other surface.