JPH08153944A - Mounting structure of electronic components - Google Patents

Abstract

PURPOSE: To realize mounting structure of an electronic component which exerts no influence upon element performance, can realize a single surface circuit board, and enables cost reduction. CONSTITUTION: The tip parts of leads 21 of a fluorescent display tube 2 are bent. The bent parts 21a are fixed on the surface side of the printed board 1 similarly to a resistance element 3 by using solder 4a. Thereby, as the soldering process at the time of mounting, only the reflow process is applied, and the tip process wherein the leads are dipped in a solder both is unnecessary. It is also unnecessary for a through hole to be formed in the printed board 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component mounting structure for mounting electronic components such as a fluorescent display tube and a resistance element on a printed circuit board by soldering.

[0002]

2. Description of the Related Art FIGS. 3A and 3B are views showing a conventional electronic component mounting structure, in which FIG. 3A is a side view and FIG. 3B is a front view. Further, FIG. 3 shows a structure in which a fluorescent display tube used for an interior clock of an automobile is mounted. In FIG. 3, 1 is a printed circuit board, 2 is a fluorescent display tube, 3 is a resistance element, 4a and 4b are solders, respectively. Assembling and mounting the fluorescent display tube 2 and the resistance element 3 on the printed circuit board 1 is performed by wiring. It is performed as follows from the circuit pattern, the structure of each electronic component, and the like.

First, cream solder is printed on a predetermined circuit pattern on the printed circuit board 1, and a resistance element 3 having connection leads formed at the element end is mounted on that portion. Then, hot air of 235 ° C. to 240 ° C. is blown to melt the cream solder by a reflow process, and the resistance element 3 is fixed onto the printed board 1 by the solder 4a. Next, after inserting the plurality of connecting leads 21 of the fluorescent display tube 2 into through holes (not shown) formed in the printed circuit board 1 and projecting them to the back surface side of the printed circuit board 1, 265 ° C. to 270 ° C.
A so-called dipping process is performed in which the solder is filled in a solder bath filled with a molten solder. As a result, the fluorescent display tube 2 is fixed to the printed board 1 by the solder 4b.

[0004]

By the way, in the above-mentioned conventional mounting structure, the lead 21 of the fluorescent display tube 2 is connected to the substrate 1.
The dip process is indispensable because it is mounted through the through hole of the device. However, if this dip process is performed, it will affect each element, especially the crystal oscillator, electrolytic capacitor, etc., resulting in performance degradation. There is. Further, in the conventional mounting structure, it is necessary to form a through hole in the printed board 1, resulting in a high cost, and it is difficult to form the circuit board itself on one side.

The present invention has been made in view of such circumstances, and an object thereof is to mount an electronic component which can realize a single-sided circuit board without affecting the element performance and reduce the cost. To provide the structure.

[0006]

In order to achieve the above object, the present invention provides a mounting structure for an electronic component, wherein a lead of the electronic component is fixed to a predetermined circuit pattern on a printed circuit board by soldering. The lead tips of the components are folded back and bent, and the bent portions are fixed to the one surface side of the substrate by soldering. Further, in the mounting structure of the present invention, at least one tip of the leads of the electronic component is inserted into the positioning hole formed on the substrate.

[0007]

According to the electronic component mounting structure of the present invention, when mounting an electronic component on a printed circuit board, for example, cream solder is printed on a predetermined circuit pattern of the printed circuit board,
The bent portion of each lead of the electronic component having the bent lead end portion is positioned and mounted at a predetermined position. And 235
The cream solder is melted in a reflow process by blowing hot air of ° C to 240 ° C, and the electronic component is fixed to one surface side of the printed board by the solder. This completes the implementation. That is, the soldering process at the time of mounting is only the reflow process, and the dipping process of putting it in the solder bath is not performed. Therefore, it does not affect the device performance. Also,
The printed circuit board does not need to have through holes.

Further, in the structure in which at least one tip of the leads of the electronic component is inserted into the positioning hole formed on the substrate, the positioning of the component at the time of assembly is facilitated and the work efficiency is improved.

[0009]

1 is a side view showing a first embodiment of a mounting structure for electronic parts according to the present invention, and FIG.
The same components as those are denoted by the same reference numerals. That is, 1
Is a printed circuit board, 2 is a fluorescent display tube, 3 is a resistance element, and 4a.
Indicates solder respectively.

In this mounting structure, the lead 2 of the fluorescent display tube 2 is used.
The tip portion of 1 is folded back and bent to form a so-called "J" shape, and the bent portion 21a is fixed on the front surface side of the printed circuit board 1 by the solder 4a similarly to the resistance element 3.
Therefore, the soldering process at the time of mounting is only the reflow process, and the dipping process of putting it in the solder bath is not performed. Further, it is not necessary that the printed board 1 be provided with through holes. As a result, the fluorescent display tube 2 and the resistance element 3 are assembled and mounted on the printed board 1 as follows.

First, cream solder is printed on a predetermined circuit pattern on a printed circuit board 1 to form a resistance element 3 in which connection leads are formed at the element ends and a fluorescent display tube 2 in which the lead tips are bent. The bent portion 21a of the lead 21 is positioned and mounted at a predetermined position. And 235 ° C
The cream solder is melted in a reflow process by blowing warm air of ˜240 ° C., and the fluorescent display tube 2 and the resistance element 3 are fixed onto the printed board 1 by the solder 4a. This completes the implementation.

As described above, according to the first embodiment, the tip portion of the lead 21 of the fluorescent display tube 2 is bent back and bent, and the bent portion 21a is soldered 4a in the same manner as the resistance element 3. Since it is fixed on the front surface side of the printed circuit board 1, the soldering step at the time of mounting is only the reflow step, and the dipping step of putting it in the solder bath is not performed. Also,
The printed circuit board 1 does not need to have through holes. Therefore, there is an advantage that the circuit performance can be realized without affecting the element performance and the cost can be reduced. Further, since the tip end portion of the lead 21 of the fluorescent display tube 2 is folded back and bent to form a so-called "J" shape, the shape of the tip portion can be stabilized, and it is also advantageous in terms of strength reinforcement.

FIG. 2 is a side view showing a second embodiment of a mounting structure for electronic parts according to the present invention. The second embodiment is different from the above-described first embodiment in that among the plurality of leads 21 of the fluorescent display tube 4, only four leads located at four corners, or both sides of either one of them. The lead is not bent but remains straight and is inserted into the separation hole of the printed circuit board 1 and fixed, and the positioning is performed.

According to the second embodiment, not only the same effects as those of the first embodiment described above can be obtained, but also the positioning of the parts at the time of assembly can be facilitated and the working efficiency can be improved. There are advantages. It should be noted that the number of positioning leads does not have to be four as in the present embodiment, but at least one is effective for positioning.

[0015]

As described above, according to the mounting structure of the electronic component of the present invention, there is an advantage that the performance of the element is not affected and the circuit board can be single-sided and the cost can be reduced. .

[Brief description of drawings]

1A and 1B are views showing a first embodiment of a mounting structure of an electronic component according to the present invention, in which FIG. 1A is a side view and FIG. 1B is a front view.

2A and 2B are diagrams showing a second embodiment of a mounting structure of an electronic component according to the present invention, in which FIG. 2A is a side view and FIG. 2B is a front view.

FIG. 3 is a diagram showing a mounting structure of a conventional electronic component, (a)
Is a side view and (b) is a front view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Printed circuit board 2 ... Fluorescent display tube 21 ... Lead 21a ... Bent part 3 ... Resistor element 4a ... Solder

Claims (2)

[Claims] 1. A mounting structure of an electronic component, wherein a lead of an electronic component is fixed to a predetermined circuit pattern on a printed circuit board by soldering, wherein a tip end portion of the lead of the electronic component is bent back and bent, and the bent portion is A mounting structure for electronic components that is fixed to one side of the board by soldering. 2. The mounting structure for an electronic component according to claim 1, wherein at least one tip of the leads of the electronic component is inserted into a positioning hole formed on the substrate.