JP2667682B2 - Electronic component mounting structure and mounting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a mounting structure of an electronic component suitable for mounting an electronic component whose outer case is made of a conductor such as metal on a substrate. Regarding the implementation method.

[Conventional technology]

Electronic components, like crystal oscillators and some transistors, have protection against external forces and a shielding function.
An outer case made of metal is used. When such an electronic component is mounted on the substrate, an electrical short circuit may occur due to contact between the outer case of the electronic component and the conductor pattern installed on the substrate.

Therefore, conventionally, as shown in FIG. 3, for example, when a crystal oscillator is used as an electronic component, the conductor pattern 12 is formed by contact between the conductor pattern 12 on the upper surface of the double-sided printed board 10 and the outer case of the crystal oscillator 14. As a means for avoiding a short circuit between them, an insulating spacer 16 made of an insulating material such as bakelite is inserted between the crystal oscillator 14 and the double-sided printed board 10. By inserting the insulating spacer 16, the insulation between the electronic component and the conductor pattern 12 is always maintained.

Regarding the insertion of the insulating spacer 16, the following methods are roughly classified. As a first method, the insulating spacer 16 is fixed to the lead pin 18 of the crystal oscillator 14 through the through hole 20, and then attached to the lead hole 22 of the double-sided printed circuit board 10 and soldered. As a second method, the through holes 20 of the insulating spacer 16 are aligned with the lead holes 22 of the double-sided printed circuit board 10 and fixed to each other, and then the lead pins 18 of the crystal oscillator 14 are attached to the through holes 20 and both surfaces of the insulating spacer 16. It is to be inserted and soldered according to the lead holes 22 of the printed circuit board 10.

[Problems to be solved by the invention]

By the way, in such a mounting structure of an electronic component, the insulating structure is usually performed by using a hard insulating spacer, for example, when an excessive external force is applied to the insulating spacer at the time of mounting the electronic component. Is easily destroyed.

In the electronic component mounting method, an insertion step is required for each of a plurality of insulating spacer required portions scattered on one printed circuit board, which significantly complicates the electronic circuit forming step.

Therefore, an object of the present invention is to provide a mounting structure and a mounting method for an electronic component in which an insulating spacer insertion step is omitted and an insulating material, such as a conventional bakelite, that replaces the insulating spacer is placed on a substrate for insulation. And

[Means for solving the problem]

As shown in FIG. 1, the electronic component mounting structure of the present invention is formed after a predetermined time has elapsed by printing a foamable insulating synthetic resin on an arbitrary position of a substrate on which a conductor pattern is formed. An electronic component is mounted on the mounting surface of the substrate with a protrusion so as to be spaced from the mounting surface.

Further, as shown in FIG. 2, the electronic component practical method of the present invention is such that a foamable insulating synthetic resin is printed at an arbitrary position on the surface of the substrate where the electronic component is installed, and after a predetermined time has elapsed. The method further comprises a step of forming a protrusion having an arbitrary height, and a step of placing an electronic component on the protrusion and connecting a lead of the electronic component and a conductor pattern.

[Action]

As described above, in the electronic component mounting structure of the present invention, the outer case is made of metal by forming the protrusion made of the foamable insulating synthetic resin at an arbitrary position on the substrate on which the conductor pattern is formed. The electronic component and the conductor pattern on the board are insulated by a protrusion made of insulating synthetic resin to prevent an electrical short circuit.

Then, in the electronic component mounting method of the present invention, a step of forming a protrusion having an arbitrary height using a foamable insulating synthetic resin, and mounting the electronic component on the protrusion and forming a lead of the electronic component. By connecting the conductive pattern
A mounting structure for insulating an electronic component having a metal outer case is formed before mounting the electronic component.

〔Example〕

FIG. 1 shows an embodiment of a mounting structure for electronic parts according to the present invention. In this embodiment, a double-sided printed board 30 is used as the board.
In addition, the crystal oscillator 32 is used as an electronic component whose outer case is made of metal.

The double-sided printed circuit board 30 is formed by forming a conductor pattern 36 on both sides of a base 34 made of a synthetic resin such as glass or epoxy by etching or the like, and then covering the base with the conductor pattern 36 excluding the land 38 and soldering. The resist 40 is formed. This double-sided printed circuit board 30 has a crystal oscillator
A plurality of lead holes 44 for determining the insertion positions of the 32 lead pins 42 are provided at various places, each of which is connected to the opposing surface of the double-sided printed circuit board 30. Since the connection and fixing of the lead pins 42 to the conductor pattern 36 are performed by soldering, lands 38 for fixing solder correspond to the lead pins 42 of the individual components on the back side of the board on which the individual electronic components are mounted. Will be installed. In the double-sided printed circuit board 30 shown in FIG.
The land 38 for fixing the 42 is formed on the back surface side of the double-sided printed circuit board 30.

In order to avoid contact between the outer case of the crystal oscillator 32 and the solder fixed to the conductor pattern 36 or the land 38 of the double-sided printed circuit board 30, the part where the double-sided printed circuit board 30 where the crystal oscillator 32 is mounted is installed. Projection made of conductive synthetic resin
46 will be installed. The mode of installation of the protrusion 46 is determined in consideration of the installation state of the electronic components mounted around, the shape sufficient to stably insulate and hold the crystal oscillator 32, and the like.
In the example shown in FIG. 1, in consideration of the position of the land 38 including the lead hole 44, a pillow-shaped projection 46 is installed at a position where the lead hole 44 and the surrounding land 38 are not blocked. There is. For the protrusion 46, various synthetic resins having insulating properties and heat resistance can be used.

Next, FIG. 2 shows an embodiment of a mounting method for electronic parts according to the present invention. FIGS. 2A and 2B show a front view and a cross-sectional view of the double-sided printed circuit board 30 shown in FIG.
On the double-sided printed board 30, a base material 34, a conductor pattern 36, and a solder resist 40 are formed.

Next, FIGS. 2C and 2D are front views showing a state in which the protrusion 46 made of an insulating synthetic resin is installed on the double-sided printed circuit board 30 shown in FIGS. 2A and 2B. A sectional view is shown. The protrusions 46 that support the crystal oscillator 32 are formed at three locations between the crystal oscillator 32 and the double-sided printed circuit board 30, of which the one located at the center is formed larger than the others. This takes into account the positions of the lands 38 and the lead holes 44 around which the crystal oscillator 30 is mounted, as described above.

In the formation of the protrusion 46, various forms are considered depending on the composition of the insulating synthetic resin used, and for example, when the one whose volume is constant regardless of external factors and whose viscosity is extremely high is used. May be performed by a dispenser or the like.
In addition, when a foaming material whose volume is constant after a predetermined time has elapsed is used, it can be performed by a printing technique. In this way, the protrusion 46 can be formed using a normal hybrid IC process such as coating and drying.
This is advantageous in that the number of components is reduced, the structure is simplified, and the like, as compared with an insulating spacer 16 that is formed and used for each component as in the related art.

Next, FIGS. 2 (E) and (F) show a front view and a sectional view of a state in which the crystal oscillator 32 is mounted on the double-sided printed circuit board 30 after the protrusion 46 is formed. The mounting and soldering of the crystal oscillator 32 on the double-sided printed circuit board 30 may be performed by an automatic mounting machine, an automatic soldering machine, or the like. In this case, if the protrusion 46 is not completely solidified, the crystal oscillator
Since the soldering can be performed in a state where the projection 32 and the projection 46 are partially bonded, the soldering can be performed stably. As is clear from comparison with the conventional drawing shown in FIG. 3, the formation of the protrusion 46 is the same as the conventional insulating spacer.
This is the same as increasing the size of the 16 through holes 20, so that when mounting a component using an automatic component mounter or the like, it becomes easy to determine the insertion position of the component, etc., and the degree of freedom in component mounting is increased. be able to.

In this embodiment, a crystal oscillator has been described as an example of the electronic component mounted on the substrate.
The present invention is not limited to the crystal oscillator, and can be similarly applied to all electronic components having an outer case made of metal. Further, the present invention can be similarly applied to an electronic component in which the outer case is made of a substance other than conductive.

〔The invention's effect〕

As described above, according to the mounting structure of the electronic component of the present invention, the electronic component constituting the outer case is made of metal and the conductor pattern on the substrate are insulated by the protrusion made of the foamable insulating synthetic resin. Since electrical short circuits are prevented, stable mounting of electronic components becomes possible.

According to the electronic component mounting method of the present invention, since the mounting structure for insulating the electronic component of which the outer case is made of metal is formed before the mounting of the electronic component, the insulating spacer which has been required until now is required. If the protrusion is formed by applying a foaming insulating synthetic resin by a printing technique, it is possible to form the substrate and to form a protrusion made of a plurality of insulating synthetic resins. The formation can be performed simultaneously.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a mounting structure of an electronic component of the present invention, FIG. 2 is a front view and a sectional view showing an embodiment of a method of mounting an electronic component of the present invention in the order of steps, and FIG. FIG. 3 is a front view and a cross-sectional view showing a mounting structure of the electronic component of FIG. 30 …… Double-sided printed circuit board (board) 32 …… Crystal oscillator (electronic component) 36 …… Conductor pattern 42 …… Lead pin (lead) 44 …… Lead hole 46 …… Projection

Claims (2)

(57) [Claims] 1. An electronic component in which a foamable insulating synthetic resin is printed at an arbitrary position on a substrate on which a conductor pattern is formed, and is separated from a mounting surface of the substrate by a protrusion formed after a predetermined time elapses. Mounting structure of electronic components. 2. A step of printing a foaming insulating synthetic resin at an arbitrary position on a surface of a substrate where an electronic component is installed, and forming a protrusion having an arbitrary height after a predetermined time has passed, and the protrusion. Mounting an electronic component thereon and connecting a lead of the electronic component and a conductor pattern.