JP2006217785A - Miniaturization of dc-dc converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a DC-DC converter which can be miniaturized, with regard to a power supply device capable of obtaining the power supply of a desired DC voltage using a specific DC power supply. <P>SOLUTION: The fitting hole 12a in a prescribed pattern position of a flexible circuit board is formed larger than the diameter of a terminal pin 13, two tongue pieces 12b which are oppositely oriented to the center portion and arranged symmetrical to each other, the pattern and the terminal pin 13 are brought into contact with each other by the elasticity of the tongue pieces 12b, and preliminary solder S is set on the tongue piece patterns to be mutually soldered. Furthermore, a recessed part is formed on the lower surface of a transformer to accommodate a plate-mounted circuit component therein. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a power supply apparatus that obtains a power supply of a desired DC voltage using a specific DC power supply.

Technical background

  In general, a DC-DC converter is configured as a converter block in which necessary elements are integrated, and this converter block is attached to a substrate of a device using the DC-DC converter. FIG. 5 shows an example of the structure.

  In FIG. 5, a converter block in which a transformer 1 is mounted via a plurality of transformer terminal pins 13 on a converter circuit board 42 on which a plurality of circuit components P such as resistors and semiconductors are surface-mounted is a device block such as an audio product. On the main board 41, it is attached and used as one component unit via the circuit board terminal pin 43. C is a large capacitor, which is a component of the DC-DC converter, but is mounted on the main board 41 for the sake of size. As understood from FIG. 5, the circuit pattern conductor of the converter circuit board 42 is formed on the surface facing the main board 41, so that the circuit component P mounted on the circuit pattern conductor is also on the main board 41. Therefore, the spacer 44 is required to prevent the circuit component P from coming into contact with the main board 41, and the spacer 44 is used in the state shown in FIG. A constant distance from the circuit board 42 is maintained. In this example, the spacer 44 has a pipe shape that penetrates the terminal pin 43, but may have other shapes.

  In such a structure, as apparent from FIG. 5, both the height H and width W of the converter block comprising the transformer 1, the converter circuit board 42, the circuit component P, the spacer 44, etc. In the tablock, it becomes larger than the largest transformer 1, which is an obstacle when it is necessary to make the configuration of the equipment compact, and downsizing is eagerly desired. An object of the present invention is to provide a DC-DC converter that can meet such demands and can be further reduced in size.

Means to solve the problem

  According to the present invention, the above-described problem is that a transformer for transforming an alternating voltage, a circuit component that constitutes a DC-DC converter circuit together with the transformer, and a DC-DC converter are attached to and connected to a board of a target device In a DC-DC converter comprising a terminal pin for performing the operation and a converter circuit board on which the transformer, the circuit component, and the terminal pin are mounted, the converter circuit board has the circuit component on its surface. Surface mounting and the mounting surface side and the lower surface of the transformer are arranged to face each other, the terminal pins protrude downward from the lower surface of the transformer, and a predetermined pattern portion of the converter circuit board arranged face to face The problem is solved by penetrating the mounting hole and electrically connecting to the converter circuit board at the portion.

  Further, according to the present invention, the converter circuit board is formed of a flexible board material according to the present invention, and the attachment hole of the predetermined pattern portion of the converter circuit board is formed larger than the diameter of the terminal pin. In addition, two tongue pieces symmetrically arranged from the peripheral edge of the mounting hole toward the center portion are extended, and the pattern comes into contact with the terminal pin by the elasticity of these tongue pieces and is set to the tongue piece surface pattern. It can be solved by soldering to each other with spare solder.

  In addition, according to the present invention, the above-described problem is solved by forming a recess in the lower surface of the transformer in the previous section and accommodating a circuit component surface-mounted in the recess.

The invention's effect

  According to the present invention, a transformer for transforming an alternating voltage, a circuit component that constitutes a DC-DC converter circuit together with the transformer, and a DC-DC converter for attaching and connecting a device to be attached to a substrate. In a DC-DC converter comprising a terminal pin, the transformer, the circuit component, and a converter circuit board on which the terminal pin is mounted, the converter circuit board surface-mounts the circuit component on its surface and the mounting surface side And the lower surface of the transformer are opposed to each other, the terminal pin protrudes downward from the lower surface of the transformer, and passes through a mounting hole at a predetermined pattern portion of the converter circuit board disposed on the opposite surface. Since it is electrically connected to the converter circuit board, the size of the converter circuit board Or equal to the area of the lower surface of the transformer, or can be made small, there is advantageous effect that it is possible to miniaturize the DC-DC converter.

  Further, the converter circuit board is formed of a flexible board material, and the mounting holes at the predetermined pattern portions of the converter circuit board are formed larger than the diameter of the terminal pins and symmetrically arranged from the periphery of the mounting holes toward the center. Since two tongue pieces were extended, the patterns were brought into contact with each other with the terminal pins sandwiched by the elasticity of these tongue pieces, and soldered to each other by a preliminary solder set in the tongue piece surface pattern. There is an advantageous effect that it is possible to eliminate the difficulty of soldering the terminal pins.

  Further, the elimination of the circuit board terminal pins and the spacers to the converter circuit, the reduction of the converter circuit board, and the downsizing of the converter block have advantageous effects that can be made economically inexpensive.

  The converter circuit board on which the transformer, circuit components, terminal pins, etc. are mounted is arranged so that the circuit components are surface-mounted on the surface and the mounting surface side faces the lower surface of the transformer, and the terminal pins are downward from the lower surface of the transformer. It protrudes and passes through a mounting hole at a predetermined pattern portion of the converter circuit board arranged face-to-face, and is electrically connected to the circuit board at this portion. In order to eliminate the difficulty of soldering with the terminal pins of the transformer because the soldering surface of the converter circuit board faces the lower surface of the transformer, the converter circuit board is formed of a flexible board material. The mounting hole at a predetermined pattern portion is formed larger than the diameter of the terminal pin and two tongue pieces arranged symmetrically from the periphery of the mounting hole toward the center portion, and the pattern is formed by the elasticity of these tongue pieces. The pins are brought into contact with each other and are soldered to each other by a spare solder set on the tongue surface pattern.

  A recess is formed on the lower surface of the transformer. By doing so, the circuit components surface-mounted in this recess can be accommodated, the whole can be made smaller, and the size of the converter circuit board is equal to or smaller than the area of the lower surface of the transformer be able to.

  FIG. 1 shows a structural example of the present invention. In FIG. 1, reference numeral 12 denotes a converter circuit board, and a flexible circuit board is used in this embodiment. Hereinafter, it is referred to as a flexible circuit board. A plurality of circuit components P are surface-mounted on the surface of the flexible circuit board 12. Reference numeral 1 denotes a transformer, on which a flexible circuit board 12 on which a circuit component P is surface-mounted is disposed. In this arrangement, the circuit component P is disposed so that the surface on which the circuit component P is present faces the lower surface of the transformer 1. Reference numeral 13 denotes a terminal pin that protrudes downward from the peripheral edge of the transformer 1, for example, the four corners, whereby the coil end of the transformer 1 is connected to a predetermined pattern portion of the flexible circuit board 12. Since the base portion of the terminal pin 13 is formed so as to slightly protrude from the main body portion of the transformer 1, a concave portion K exists on the lower side of the transformer 1. When the flexible circuit board 12 on which the circuit component P is surface-mounted is disposed on the lower surface side of the transformer 1, the circuit component P is well accommodated in the recess K.

  Reference numeral 41 denotes a main board of the device. The flexible circuit board 12 as the converter circuit board is mounted and connected to the main board 41 via the terminal pins 13.

  Since the soldering surface of the flexible circuit board 12 is on the circuit component side, that is, the side facing the lower surface of the transformer 1, it is necessary to devise connection with the terminal pins 13 of the transformer 1.

  2A and 2B show the structure of this portion. A hole 12 a into which the terminal pin 13 is inserted is formed at a predetermined portion of the circuit pattern of the flexible circuit board 12. The hole 12a is set to be considerably larger than the diameter of the terminal pin 13, and two tongue pieces 12b are symmetrically extended from the green side of the hole toward the center. The dimension of the gap between the tips of the two tongue pieces 12b is set to be slightly smaller than the diameter of the terminal pin 13. Further, preliminary solder S is applied to the tips of the two tongue pieces 12b.

  As shown in FIG. 2B, when the terminal pin 13 is inserted in the direction of arrow D toward the gap between the tips of the two tongue pieces 12b, the elasticity of the two tongue pieces 12b acts, as shown in FIG. It becomes a state. When heated in this state, the preliminary solder S is melted and the predetermined portion of the circuit pattern of the flexible circuit board 12 and the terminal pin 13 are connected.

  3A and 3B show an embodiment in which a single-sided printed board is applied instead of the flexible circuit board 12. In FIG. 3B, a semicircular hole 14a for inserting the terminal pin 13 of the transformer is formed in the single-sided printed circuit board 14 on the end face of the board. Preliminary solder S is applied to a predetermined region around the semicircular hole 14a. As shown in FIG. 3A, the terminal pin 13 of the transformer is easily soldered after being inserted into the semicircular hole 14a of the single-sided printed circuit board 14.

  FIG. 4 shows an example of a general DC-DC converter circuit. Although the description is omitted because it is a known technique, the reference numerals in the circuit diagram are given in accordance with the above description.

  If a double-sided board is used for the flexible circuit board 12 as the converter circuit board, the connection procedure can be further omitted.

  It is a side view of one Example of this invention.   (A) (B) is explanatory drawing of the structure of the end pin connection part of this invention.   (A) (B) is explanatory drawing of the structure of the other Example of this invention.   It is a circuit diagram explaining the Example of this invention.   It is a side view of the conventional structural example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transformer 41 Main board 12 Flexible circuit board 12a Hole 12b Tongue piece 13 Terminal pin 14 Single-sided printed circuit board 14a Semicircular hole P Circuit component S Spare solder

Claims (3)

A transformer that transforms AC voltage;
Circuit components constituting a DC-DC converter circuit together with the transformer;
A terminal pin for attaching and connecting the DC-DC converter to the substrate of the device to be attached;
A converter circuit board for mounting the transformer, the circuit component, and the terminal pin;
In a DC-DC converter comprising:
The converter circuit board is mounted so that the circuit component is surface-mounted on the surface and the mounting surface side and the lower surface of the transformer face each other.
The terminal pin protrudes downward from the lower surface of the transformer, penetrates through a mounting hole of a predetermined pattern portion of the converter circuit board arranged facing, and is electrically connected to the circuit board at the portion. DC-DC converter characterized.   The converter circuit board is formed of a flexible board material, and the mounting holes at the predetermined pattern portions of the converter circuit board are formed larger than the diameter of the terminal pins, and the two tongue pieces are arranged symmetrically from the green of the mounting hole toward the center. 2. The pattern of claim 1, wherein the patterns are brought into contact with each other by the elasticity of these tongue pieces, and are soldered to each other by a preliminary solder set in the tongue piece surface pattern. DC-DC converter.   3. The DC-DC converter according to claim 1, wherein a concave portion is formed on a lower surface of the transformer, and a circuit component surface-mounted in the concave portion is accommodated.

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