JP3233348B2 - On-board power supply and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-board power supply device and a method of manufacturing the same, and more particularly, to a structure capable of improving a volume utilization factor for a large electronic component such as a magnetic component or a power transistor, and an assembling method. The present invention relates to an on-board power supply device capable of improving a work yield and a method of manufacturing the same.

[0002]

2. Description of the Related Art DC-
2. Description of the Related Art A so-called on-board power supply device in which all components such as a DC converter are mounted on a metal substrate has become widespread, and its performance has been further developed to achieve high efficiency and miniaturization. With the progress, high power output of several hundred watts is being realized by a small on-board power supply.

[0003] In this on-board power supply device, when the output becomes large, the volume occupied by magnetic components such as inductors and transformers and the amount of heat generated thereby increase. Therefore, 1
In a structure in which all components are mounted on a single metal substrate, there are problems of volume utilization and heat radiation. In addition, it is conceivable to attach a child board above the metal board, but when attaching to the metal board, since all are by surface mounting, there are difficulties in the manufacturing method such as keeping the interconnection terminals on the same plane. . Since there are a large number of terminals for this interconnection, positioning accuracy is a major problem.

[0004] In connection with this problem, for example, Utility Model Registration Publication No. 255 issued on November 5, 1997
In the hybrid integrated circuit device described in No. 3083, a metal substrate having a circuit formed with an insulating layer interposed therebetween, and a printed circuit board supported by a predetermined distance from the metal substrate with an opening at a substantially central portion thereof A first electronic component having a large calorific value disposed at a predetermined position of a circuit formed on a metal substrate facing the opening of the printed board; and a notch provided around the opening. A second electronic component having a large heat value and standing on the metal substrate so as to be partially fitted, and a third electronic component having a small heat value disposed at a predetermined position of a circuit formed on the printed circuit board; A hybrid integrated circuit device including components has been proposed.

[0005] This invention has an effect that, for an electronic component that consumes a large amount of power, an electronic component that generates a small amount of heat does not require a component whose temperature is assured as an electronic component that generates a large amount of heat while maintaining effective heat dissipation means. To play. However, no mention is made of the problem of the positioning accuracy of the interconnection terminals.

[Problems to be solved by the invention]

The present invention provides an on-board power supply device in which a converter circuit and the like are mounted on a metal substrate, to obtain a mounting structure for improving the volume utilization rate of large components such as magnetic components and power transistors, and to perform assembly work. It is an object to improve the yield.

[0007]

Means for Solving the Problems To solve the above-mentioned problems, a first aspect of the present invention is a terminal including an input terminal having a plurality of pins and an output terminal having a plurality of pins, an inductor, and a control circuit. And an on-board power supply device having a main circuit, a metal substrate which is a parent substrate on which terminal pins are mounted together with electronic components of the main circuit, and an outer shape having a size substantially equal to the size of the outer shape of the metal substrate. An insulating substrate including a frame surrounding the large window and a pin of a terminal pressed into the frame, and a grandchild substrate having an outer shape substantially equal to or smaller than the outer size of the insulating substrate. The half-window, which is a space for inserting the inductor, is clear, and the printed circuit board with the terminal pins inserted through the edge of the grandchild board, the space for the large window on the insulating material board, and the space for the half-window on the printed circuit board Space where The present invention provides an on-board power supply characterized in that an inductor is mounted on a surface of a metal substrate corresponding to the above, and its lead wire is connected to a pin of a terminal extending through a frame portion of the printed circuit board.

According to a second aspect of the present invention, there is provided a method for manufacturing an on-board power supply device according to the first aspect, wherein cream solder is applied to an upper surface of a metal substrate, and the cream solder is applied. A first step of mounting electronic components of the main circuit on the solder, and a second step of press-fitting a plurality of pins of the terminal into the insulating material substrate by pressing the plurality of pins into the insulating material substrate and aligning a plurality of positioning pins into the insulating material substrate. A third step of placing the insulating substrate into which the terminal pins and the positioning pins are press-fitted on the upper surface of the metal substrate and inserting the terminal pins and the positioning pins into predetermined holes, and a fourth step of welding cream solder And a fifth step of soldering the terminal pins through each through hole of the printed circuit board on which the electronic components of the control circuit are mounted and soldering, and the space surrounded by the frame portion of the insulating material board and the half window of the printed circuit board. A sixth step of mounting an inductor on a surface of a metal substrate corresponding to the overlapping space and soldering its lead wire to a printed circuit board.

[0009]

FIG. 1 is a diagram for explaining the configuration and assembly of an on-board power supply according to the present invention.
In FIG. 1, 1 is a metal substrate serving as a parent substrate, 2 is an insulating material substrate serving as a child substrate, 3 is a printed board serving as a grandchild substrate,
Is a main circuit, and large electronic components such as power transistors are mounted on the metal substrate 1. The on-board power supply device to be manufactured here includes an input terminal, an output terminal, an inductor that is a magnetic component, a control circuit, and a main circuit. In general, the power supply is roughly divided into a main circuit that handles the load current including a main switching element, a transformer, and a smoothing circuit on the input / output side, and a control circuit that controls the load current. Follow the conventional.

The metal substrate 1 has a thick metal layer 11.
And a thin insulating layer 12 and a conductor film (not shown) on the upper surface thereof, and have a rectangular shape. Electronic components of the main circuit 4 such as a converter circuit are mounted on the upper surface of the conductive film of the metal substrate 1. Also, as is apparent from FIG. 1, terminals 8 such as input terminals 81 and output terminals 82 are mounted on the upper surface of the conductive film of the metal substrate 1, and serve as input / output connection paths for the entire main circuit. A columnar spacer (not shown) is vertically attached to two locations at the end of the metal substrate 1 to serve as a support for the on-board power supply.

The insulating material substrate 2 is made of a thin plate of glass epoxy material having substantially the same size as the metal substrate 1, has a large window 21, and an edge 22 around the large window 21. The edge portion 22 is provided with holes for inserting pins of the terminals 8, but none of the holes has through-hole plating or lands like a general printed circuit board.

The printed board 3 is also substantially the same size as the metal board 1, and through holes are plated with holes like a general printed board, and there are lands. The printed circuit board 3 has a half window 31 smaller than the large window 21.
Are formed, and the half window 31 overlaps most of the large window 21. The printed circuit board 3 has an edge portion 32 around the half window 31 and a plain portion 33 which is a surface area excluding the edge portion 32.

The manufacturing method will be described below in the order of steps.

As a first step, cream solder is applied to the upper surface of the metal substrate 1 as the parent substrate, and the electronic components of the main circuit 4 are mounted.

In the second step, the terminals 8 composed of a large number of pins are press-fitted into the insulating material substrate 2 as a daughter board, and the protruding lengths of the press-fitted terminals 8 are evenly aligned as shown by a dashed line. Further, positioning pins 8 are provided on the insulating material substrate 2.
3, 84, and press-fit the length of each pin of the terminal 8,
Make it slightly longer.

As a third step, the insulating material substrate 2, which is the child substrate into which the pins are pressed, is placed on the upper surface of the metal substrate 1. At this time, the positioning pins 83 and 84 are inserted into the reference holes 13 and 14 of the metal substrate 1.

As a fourth step, the cream solder is welded by a predetermined temperature treatment. Each solder location after the welding step is visually recognized through the large window 21.

As a fifth step, the pins 8 are inserted into the through holes of the printed circuit board 3 serving as the grandchild board on which the control circuit and the like are mounted, and soldered.

As a sixth step, the inductor 5 is exposed through the space between the large window 21 and the half window 31 that overlap each other.
That is, they are placed on a part of the surface area of the metal substrate 1 corresponding to the space (position 15 shown by the broken line in the figure), and these lead wire terminals 51, 52 are connected to the lands 36,
37, respectively. _

By these six steps, an on-board power supply device can be manufactured.

Then, if necessary, the long pins are cut while leaving the pins for external drawing such as the input terminal 81 and the output terminal 82. If the length of each pin 8 is selected in advance to a predetermined length, the cutting operation can be omitted.

FIG. 2 is an embodiment of the mounting structure of the on-board power supply according to the present invention, and is a top view of the on-board power supply completed according to the above-described manufacturing method, and FIG. 3 is a side view thereof. It is. 2 and 3,
1 have the same reference numerals, respectively, and correspond to the same components. In the mounting structure of this on-board power supply,
At both ends of the metal substrate 1, columnar spacers 7 shown in FIG. The structure surrounded by the metal substrate 1 and the plastic case 9 shown in FIG.
A cooling fin (not shown) is mounted on the back surface of the metal substrate 1 while being mounted on another print or the like.

[0023]

The present invention has the above-described features, so that the terminals can be easily mounted and the yield during the assembly operation can be improved. Further, since large parts have large heat loss loss, it is desired that the temperature distribution on the heat radiation of the on-board power supply device be leveled to reduce the size and improve the reliability. The circuit mounted on the grandchild board is made of relatively low power components, so that the volume utilization rate can be further increased. Furthermore, since all of the many pin terminals are inserted into and fixed to one insulating material substrate, each pin terminal can be easily arranged and mounted with high positional accuracy. When an external force is applied, the stress is dispersed and applied to all the solder joints between the pin terminal and the metal substrate through the terminal substrate, so that the stress per terminal decreases, and the reliability of the fixing between the terminal pin and the metal substrate is reduced. This has the effect of improving the performance.

[Brief description of the drawings]

FIG. 1 shows steps of a method for manufacturing an on-board power supply device according to the present invention.

FIG. 2 shows a top view of an embodiment of the mounting structure of the on-board power supply device according to the present invention.

FIG. 3 is a side view of the embodiment of the mounting structure of the on-board power supply device according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Metal board (parent board) 2 ... Insulation board (child board) 3 ... Printed board (child board) 4 ... Main circuit 5 ... Inductor 6 ... Control circuit 7 ... Spacer 8 ... Terminal 9 ... Plastic case

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02M 3/00 H05K 1/14 H05K 1/18 H05K 7/14

Claims (2)

(57) [Claims] 1. An on-board power supply device comprising: a terminal including an input terminal having a plurality of pins and an output terminal having a plurality of pins; an inductor; a control circuit; and a main circuit. A metal substrate as a parent substrate on which the pins of the terminals are mounted together with the components; a frame having an outer shape substantially equal to the size of the outer shape of the metal substrate; a frame surrounding a large window; and press-fitting into the frame. An insulating substrate composed of the pins of the terminal, and a grandchild substrate having an outer shape substantially equal to or smaller than the outer shape of the insulating substrate, and a half window as a space through which the inductor is inserted is clear, A printed board formed by inserting the pins of the terminals through the edge of the grandchild board; and the metal board corresponding to a space in which the space of the large window of the insulating material board and the space of the half window of the printed board overlap. An on-board power supply device, wherein the inductor is mounted on a surface of the printed circuit board, and a lead wire thereof is connected to a pin of the terminal extending through a frame portion of the printed circuit board. 2. An on-board power supply device comprising: a terminal including an input terminal having a plurality of pins and an output terminal having a plurality of pins; an inductor; a control circuit; and a main circuit. A metal substrate as a parent substrate on which the pins of the terminals are mounted together with the components; a frame having an outer shape substantially equal to the size of the outer shape of the metal substrate; a frame surrounding a large window; and press-fitting into the frame. An insulating substrate composed of the pins of the terminal, and a grandchild substrate having an outer shape substantially equal to or smaller than the outer shape of the insulating substrate, and a half window as a space through which the inductor is inserted is clear, A printed board formed by inserting the pins of the terminals through the edge of the grandchild board; and the metal board corresponding to a space in which the space of the large window of the insulating material board and the space of the half window of the printed board overlap. A method for manufacturing an on-board power supply device, comprising mounting the inductor on a surface of the printed circuit board and connecting a lead wire of the inductor to a pin of the terminal extending through a frame of the printed circuit board. A first step of applying solder and mounting the electronic component of the main circuit on the cream solder; pressing a plurality of pins of the terminal into the insulating material substrate so as to make their protruding lengths uniform; A second step of press-fitting the pins into the insulating substrate; placing the insulating substrate into which the pins of the terminals and the positioning pins are press-fitted on the upper surface of the metal substrate; A third step of inserting the cream solder into a hole, a fourth step of welding the cream solder, and a step of inserting the terminal into each through hole of the printed circuit board on which the electronic component of the control circuit is mounted. A fifth step of inserting and soldering, placing an inductor on the surface of the metal substrate corresponding to the space where the half-window of the printed circuit board overlaps the space surrounded by the frame portion of the insulating material substrate, And a sixth step of soldering the lead wires to the printed circuit board.