JPH062246Y2 - High voltage resistance circuit unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a high-voltage resistance circuit unit such as a bleeder resistance package used in a horizontal output circuit of a CRT (cathorde-ray tube).

(Prior Art) Conventionally, in a high voltage resistance circuit unit for a CRT, as disclosed in, for example, Japanese Utility Model Publication No. 62-30368, a variable resistor and a fixed resistor of a horizontal output circuit of a CRT are formed on the same insulating substrate. The insulating substrate is provided on the top and integrally molded with synthetic resin to form a unit.

(Problems to be solved by the invention) In the case of the above-mentioned conventional technology, when the unit itself is made smaller due to the recent demand for miniaturization of electronic devices, the heat generated from the resistor does not sufficiently dissipate, and the resistance is reduced by long-term use. There has been a problem that the temperature of the body becomes high and the fluctuation of the circuit characteristics due to the temperature change increases.

Further, since it is used under a high voltage, there is a problem that ordinary metal heat radiation fins cannot be used.

The present invention has been made in view of the above-mentioned problems of the conventional technology. Even if the device has a small-sized high-voltage resistor circuit in which resistors are formed at high density, the heat dissipation is good, and the stability of circuit characteristics is high. Moreover, it is an object of the present invention to provide a high voltage resistance circuit unit having a high discharge prevention effect.

(Means for Solving the Problem) The present invention has a circuit board provided with a high-voltage resistance circuit for a CRT, and the board is housed in a case made of synthetic resin, and the board is synthesized to such an extent that the board is buried. A resin filler is poured into the case and solidified, and the case has an open end and a rectangular parallelepiped shape, and is made of ceramics having a plurality of protrusions formed on the outer surface of the case opposite to the opening. It is a high-voltage resistance circuit unit in which the heat radiation plate is integrally attached.

(Operation) In the high-voltage resistance circuit unit of the present invention, the heat dissipation plate integrally attached along the longitudinal direction of the case efficiently dissipates heat generated from the resistor to reduce fluctuations in circuit characteristics due to temperature. The case itself is prevented from warping due to thermal stress, and moreover, reliable discharge prevention is performed.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

This embodiment is a high voltage resistance circuit unit containing a bleeder resistance used in a horizontal output circuit of a CRT. This high-voltage resistance circuit unit has a substantially rectangular parallelepiped shape, and has a ceramic radiator plate 7 fixed to the outside of a case 3 made of synthetic resin such as Noryl resin or PBT (polybutyl terephthalate). The heat radiating plate 7 has a heat radiating projection 8 composed of a plurality of ridges, and is attached so as to cover almost the entire outer surface of the case 3 opposite to the opening side. In addition, a substrate 5 provided with a fixed resistance is installed at a predetermined position inside the case 3, and a synthetic resin filler 6 flows into the case 3 and solidifies so as to surround the entire substrate 5. .

According to the high-voltage resistance circuit unit of this embodiment, since the heat sink 7 made of ceramics is attached to almost the entire outer surface of the case 3 on the side opposite to the opening side, the discharge from the substrate 5 is prevented. Has extremely high insulation,
Further, even if a crack is generated in the case 3, the crack does not extend to the heat sink 7 made of ceramics, which is a separate body, and the safety against discharge is dramatically improved.

In addition, the heat dissipation projections of this invention have a grid shape,
It may be formed in a cylindrical shape so that the surface area is appropriately larger than that of a flat surface.

(Effect of the Invention) In the high-voltage resistance circuit unit of the present invention, the heat sink made of ceramics is integrally attached to the outer surface of the resin case, so the heat generated from the resistor inside dissipates efficiently, The temperature of the resistor or ceramic substrate and case does not rise so high. Therefore, even if the substrate or the case is made small, the heat generated from the resistor does not cause an abnormally high temperature, the circuit characteristics do not fluctuate, and it greatly contributes to the miniaturization of the CRT circuit.

Also, by attaching a ceramic heat sink to the case, the insulation against discharge from the substrate becomes extremely high, and even if a crack occurs in the case, the ceramic heat sink provided separately will not crack. It is also possible to prevent electric discharge from the cracked portion to the outside, and it is possible to dramatically improve safety against electric discharge.

Therefore, the high-voltage resistance circuit unit of this invention has an extremely high insulation effect against high voltage and a high heat dissipation effect, and is more reliable against discharge than a metal heat dissipation plate provided with an insulating film. It is high and has a higher heat dissipation effect and insulation effect than a resin heat dissipation plate, and satisfies the purposes of insulation and heat dissipation at a high level.

[Brief description of drawings]

FIG. 1 is a perspective view of a high voltage resistance circuit unit according to an embodiment of the present invention, and FIG. 2 is a vertical sectional view of the high voltage resistance circuit unit according to this embodiment. 3 ... Case, 5 ... Substrate, 6 ... Filling material, 7 ... Heat sink, 8 ... Heat dissipation protrusion

Claims (2)

[Scope of utility model registration request] 1. A circuit board provided with a high-voltage resistance circuit for a CRT, the circuit board being housed in a case made of synthetic resin, and a synthetic resin filler being filled in the case to the extent that the board is buried. In a high-voltage resistance circuit unit that has been poured and solidified, the case is made of a ceramic material having an opening and a rectangular parallelepiped shape, and a plurality of protrusions formed on the outer surface of the case opposite to the opening. A high-voltage resistance circuit unit characterized by a heat sink attached integrally. 2. The high voltage resistance circuit unit according to claim 1, wherein the heat radiating plate is attached to substantially the entire outer surface of the case opposite to the opening. .