JPS59193055A - Thyristor mounting board - Google Patents

Abstract

PURPOSE:To improve leakage resistance, short-circuit resistance, and tracking resistance by a method wherein a TRIAC, a diode, etc. are mounted on a printed board, and, when lead terminals thereof are connected to the circuit pattern on the back surface of the board by penetration through the slits provided in the board, the slit parts are covered with thixotropic resin. CONSTITUTION:The triac 3, an LED4, the diode 5, an electrolytic capacitor 6, a discrete type resistor 7, jumper wire 8, etc. are mounted on the surface of the printed board 1, and the circuit pattern 10 and a chip part 9 connected thereto are fixed to the back surface. Next, the lead terminals of the triac 3, the diode 5, etc. are connected to the pattern 10 by penetration through the slits 21 and 22 provided in the board 1, and this group of slits are filled with insulating material. At this time, epoxy resin, acrylic resin, etc. doped with thixotropic imparting agent are used as the insulating material. Thus, the substrate of high safety property to water is obtained.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention has excellent leak resistance, short circuit resistance, and leak tracking performance even when a thyristor is exposed to condensed water or water, and there is no risk of malfunction or fire. This relates to a highly safe thyristor mounting board.

Conventional configurations and their problems In recent years, in order to create products that are easier for consumers to use and have higher added value, the audio and communication fields, represented by radio, video, and television receivers, have shifted away from discrete electronic components. , which uses electronic components in the form of chips, making it possible to achieve thinner, lighter weight, and higher density. However, as the density increases, the spacing between electronic components becomes narrower, and higher leak resistance and tracking resistance are required. . However, although the usage environment in the audio and communication field requires a heat resistance of about 60 to 90 degrees Celsius, reliability and safety due to humidity are not a problem because it is not used in a high humidity atmosphere. As a special example, in order to improve the reliability and safety of the circuit pattern, several tens of micrometers of face-shaped resin is applied.

Washing machines, rice cookers, and
Even in the field of home appliances, such as dryers, we are using microcomputers to computerize them, attaching sensors, and
We are adding more functions and creating unique products. However, household electrical appliances are often used in high-humidity environments that use water, such as in bathrooms, kitchens, and under eaves, and if water condenses on electronic components due to temperature differences or is directly exposed to water, leaks may occur. Malfunctions may occur due to short circuits, tracking, etc., and in the worst case, there is a risk of fire.

If it is a mounted board consisting only of chip components, the lead terminals can be covered by dipping it in a normal liquid resin, pulling it up, draining the liquid, and curing it, but for AC circuits where the potential difference between the terminals is 100 μ or more Cyrisk is used for speed control of motors and switches in DC circuits.
It is difficult to make it into a chip, and it is outside of the discrete component '-4, and since it is a l.ryanok, several heat sinks are installed to suppress the temperature rise of the chair, so the leat part is made of resin. (It is possible to cover it by painting it, but it will not be suitable for mass production.) It is immersed in a liquid resin with no thixotrobinok properties. and cover it thickly/thickly.
It is expensive because it has poor drainage properties, dregs into hardened lees, and forms a thick film on parts that are not needed.

Therefore, only the lead parts of thyristors used in circuits where the potential difference between the terminals is 1 o○■ or more are locally coated with a thixotrobinok resin, and other electronic parts are coated by immersion. It would be better to use a material with excellent leakage, short-circuit resistance, and tracking resistance, but it is not possible to locally cover the IJ-1 on the thyristor mounting surface, the terminal and the lead terminal connected to the circuit surface and the solder at the same time. After the lead terminals on one side are locally coated and cured, the lead terminals on the other side need to be locally coated and cured, resulting in a lack of mass productivity.

Purpose of the Invention The present invention has excellent leak resistance, short circuit resistance, and tracking resistance, and prevents malfunctions even when a thyristor used in a circuit with a potential difference between terminals of 100 μ or more is directly exposed to condensation or water. The purpose is to obtain a highly safe thyristor-mounted board with no risk of fire.

Structure of the Invention In the thyristor mounting board of the present invention, the lead terminal of the thyristor is inserted into the through hole of the printed board from the first main surface side of the printed board, and the lead terminal and the wiring part are inserted into the through hole of the printed board from the first main surface side of the printed board. are electrically connected by solder, a slit is formed between the lead terminals of the printed circuit board, the lead terminals on the first main surface side are coated with chikuntropinok resin, and the leads on the second main surface side are The terminal is coated with a thixotropic resin through the slit, and at least a portion of the thixotropic resin is further coated with a moisture-proof film.

Description of Examples In the present invention, thyristors used in circuits with a potential difference between terminals of 10 oV or more include a three-terminal bidirectional triac, a reverse blocking three-terminal power 1 to syn sister, and a GTO (
Examples include, but are not limited to, reverse-blocking two-terminal semiconductor rectifier diodes.

Thixotropic resin can be obtained by adding a thixotropic M8 agent to Epoquine resin, polybutadiene resin, acrylic resin, polyester resin, etc. Modified products of these can also be used. Then, add solvents such as quinolene, toluene, methyl ethyl ketone, butyl acetate, or add red phosphorus, phosphorus compounds,
It is also possible to add flame retardants such as bromine compounds and alumina to make it flame retardant. It is desirable that the thixotropic resin has a thixotropic index of 3 or more.
If the index is less than 3, the lead terminals will be exposed even if the glue terminals are coated on the silicone mounting surface during curing, or the necessary protrusions cannot be provided on the circuit surface.

On the other hand, moisture-proof coating by dipping can use resin similar to titanium drop pink resin and has leveling properties.

It is desirable that the viscosity at the time of immersion be in the range of 200 to 2000 cps from the viewpoint of drainage properties and coverage of chip parts, semiconductors, etc.

By the way, if the width of the slit between the lead terminals of Cyrisk is too narrow, it will be difficult to create protrusions on the circuit surface, and if the slit is too wide, there is a risk that the thixotropic resin will sag during curing, and the strength of the printed circuit board and the circuit will be affected. A range of 2 to B is desirable due to the structure, and the height of the protrusion from the circuit surface needs to be at least 2 to hide the lead terminal of the cyrisk.

Hereinafter, more specific embodiments of the present invention will be described with reference to the drawings. FIGS. 1 and 2 are a plan view and a sectional view, respectively, of a printed circuit board on which a SIRISK according to an embodiment of the present invention is mounted. Slit between terminals l-2, 21
, 22 are installed on the printed circuit board 1.
0, jh4 f'1 between terminals. ;! r or 110■ triac 3, LEL14, 41, potential difference between terminals or 10
5■ semiconductor rectifier diode 6, electrolytic capacitor 6
, discrete type resistors 7, 71, jumper wires 8, and 44 resin consisting of base material or ebony/resin with a chikunotorovic index of 4.6 and hardening agent or polyamide amine on a mounting board consisting of −
Using triac 3, semiconductor,! Completely cover the lead terminals on the mounting surface of prototype TIO 1 and 5 on I, and simultaneously cover the lead terminals on the circuit surface through the slit, and cure at 100'C for 30 minutes. After creating the coating 11 with thixotropic resin, the mounting board on which the electronic circuit was formed was immersed in a resin consisting of a polyester resin as a main component with a viscosity of 510 Cps and a curing agent of Kaino 7Ane-1, and heated at 100°C for 20 minutes. The moisture-proof cover 12 was prepared by dipping the resin under the curing conditions of 10 minutes.

The thyristor-mounted board of the present invention produced as described above can be used in an electronic circuit including a thyristor under the conditions of continuous application of rated 110V at 40°C and 1oo%RH, that is, a potential difference of 100 cm or more is applied between the terminals. In a state of water or condensation,
After 10 hours passed, there was no malfunction due to malfunction or tracking, and everything was normal.

Effects of the Invention As is clear from the above description, when the thyristor is mounted on a printed circuit board, the thyristor mounting board of the present invention provides a slit between the lead terminals of the thyristor, and the titanium droppink resin is used to close the lead terminal on the thyristor mounting surface. In addition to completely covering the lead terminals on the circuit surface through the slits, it has leak resistance, short circuit resistance, and tracking resistance even when water condenses due to temperature differences or is directly exposed to water. It has advantages such as excellent performance and no risk of malfunction or fire.

[Brief explanation of drawings]

FIG. 1 is a plan view of a printed circuit board mounted with a thyristor according to an embodiment of the present invention, and FIG. 2 is a sectional view thereof. 1... Printed circuit board, 2, 21.22 A slit between the terminals, 3... A triac with a potential difference of 110 V between the terminals, 5-... A semiconductor rectifier diode with a potential difference of 105 cm between the terminals, 11 Chikuntrovinok 12 Moisture-proof coating by dipping.

Claims (3)

[Claims] (1) Insert the lead terminal of the thyristor into the through hole of the printed circuit board from the first main surface side of the printed circuit board, and electrically connect the lead terminal and the wiring part with solder on the second main surface side of the printed circuit board. A slit is formed between the lead terminals of the printed circuit board, the lead terminal on the first main surface side is coated with a technotropic resin, and the lead terminal on the second main surface side is coated with a technotropic resin. What is claimed is: 1. A thyristor mounting board, characterized in that the thyristor-mounted board is coated with a thixotropic resin, and further, at least a portion of the thixotropic resin is coated with a moisture-proof film. (2) The thyristor mounting board according to claim 1, wherein the thyristor has a voltage of 100 μ or more applied between its terminals. (3) Thixotropic index of technotropic resin (viscosity at 2 rpm on rotational viscosity side/2 Or pm
The thyristor-mounted substrate according to claim 1, wherein the thyristor-mounted substrate has a viscosity of 3 or more.