JPH07297576A - Mounting device of circuit board - Google Patents

Abstract

PURPOSE:To provide a circuit board mounting device where the leads of a circuit board enclosed in a resin case are welded to terminals by a laser beam high in reliability. CONSTITUTION:A terminal 14 is formed in one piece with a resin case formed of synthetic resin through a molding process, protruding vertical from the side wall 121 of the resin case. in a cantilever manner as its end is buried. A holding piece 16 molded concurrently at molding of the resin case is provided to the rear of the terminal 14 so as to enable the terminal 14 to withstand a pressure applied from above the front of the terminal 14. A lead piece 15 connected to a leading terminal 13 of a circuit board 11 is laid over the front of the terminal 14, and a laser welding nozzle is pressed against the terminal 14 through the intermediary of the lead piece 15 to weld the terminal 14 to the lead piece 15 by laser.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit board mounting device for housing and setting an integrated circuit device such as a hybrid IC having a circuit element mounted therein in a resin case.

[0002]

2. Description of the Related Art A circuit board forming a hybrid IC is housed in a case made of synthetic resin, for example. The resin case is provided with signal input / output terminals, and these input / output terminal portions and the circuit terminal portions of the housed circuit board are electrically connected via a terminal mechanism. Specifically, a terminal made of a metal piece is provided so as to be integrally embedded and fixed during the molding process of the resin case toward the inside for housing the circuit board of the resin case. It is connected to the lead piece made of metal foil connected to the terminal part.

Solder joining is generally known as a means for electrically and mechanically connecting the terminal and the lead piece, but laser welding exists as a new joining technique replacing the solder joining. .

Laser welding uses a welding nozzle having high thermal conductivity. As shown in FIG. 3A, a metal terminal 32 is provided by projecting from a side wall of a resin case 31 into the inside thereof. , A lead piece 33 made of a metal foil connected to a circuit board (not shown) is joined to the joining surface of the terminal 32, and the welding nozzle 34 holds the lead piece 33 so that the lead piece 33 is pressure-bonded to the terminal 32. The welding is performed by the laser light from the welding nozzle 34.

That is, the welding nozzle 34 causes the lead piece to
By crimping and holding 33 and terminal 32,
Stable thermal conductivity is secured. In this case, such stable thermal conductivity is ensured, and the inert gas purged to prevent the oxidation of the welded portion is kept constant.

[0006]

When performing such laser welding, since the welding nozzle 34 absorbs the error in the height position of the terminal 32 projecting from the resin case 31, the specified pressure is reduced. That is, the pressure directly acts on the terminal 32 protruding from the side wall of the resin case 31. Therefore, when the terminal 32 is attached to the side wall of the resin case 31 in a cantilevered state, the pressure applied by the welding nozzle 34 causes the terminal 32 to bend as shown by the arrow, and the terminal 32 and the lead piece 33 are joined. The welding nozzle 34 is not firmly attached to the body.

For example, when the terminal 32 is bent by the pressure from the welding nozzle 34, the tip of the welding nozzle 34 has a lead foil 33 on the terminal 32 as shown in FIG.
Of the welding nozzle 34, and only the corner portion of the tip of the welding nozzle 34 locally contacts the lead piece 33. That is, the balance state of heat conduction is lost, and sputter holes are locally formed in the joined body of the lead piece 33 and the terminal 32, which makes it difficult to secure the necessary welding strength.

The present invention has been made in view of the above points, and in the state where the circuit board is housed in the resin case, the lead piece connected to the circuit board and the terminal of the resin case are particularly laser welded. At the time of joining, a circuit board mounting device that ensures a reliable terminal lead-out by performing a welding operation in which the welding nozzle is stably brought into close contact with the contact state between the terminal and the lead piece It is the one we are trying to provide.

[0009]

According to another aspect of the present invention, there is provided a circuit board mounting apparatus, wherein a circuit board on which a circuit element is mounted is set in a side wall portion of a resin case to be electrically conductive toward the storage portion of the circuit board. A terminal member made of a strip of material is provided so as to project, and the tip of a lead piece made of metal foil, which is provided by being connected to the circuit terminal portion of the circuit board, is welded to the terminal member. The lead member has a holding member formed integrally with the resin case so as to support the surface on the side opposite to the surface on which the pressure acts when welding, and welds when welding the terminal member and the lead piece. The holding member receives the pressure applied by the nozzle.

[0010]

In the circuit board mounting apparatus configured as described above, the lead nozzle is placed on the joint surface of the terminal member, and the welding nozzle is pressed against the terminal member so as to be sandwiched between the lead member and the terminal member. In the state where the terminal member and the lead piece are kept crimped, for example, laser welding is performed.
At the time of this laser welding, the welding nozzle applies a pressure to bend the terminal member. The terminal member is held by the holding member so as to receive this acting pressure, and the bending of the welding nozzle due to the pressure Occurrence is stopped. In other words, during laser welding, the contact stability of the terminal member and the lead piece, and further the welding nozzle can be reliably maintained, and the joint strength between the terminal member and the lead piece can be reliably obtained. Reliability is ensured.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a state in which a circuit board 11 constituting a hybrid IC or the like is housed in a housing portion of a resin case 12 formed by molding synthetic resin.
The side wall 12 is provided with a side wall 121 so as to surround the periphery thereof, and a housing portion for the circuit board 11 is formed inside the side wall 121. Then, the circuit board 11 is inserted into the housing portion of the resin case 12, supported by a supporting mechanism (not shown), and fixedly held by a fixing mechanism.

Here, although details are omitted, the circuit board 11 is provided with a large number of circuit elements and circuit wiring for connecting them, and a terminal portion set corresponding to these circuit wirings. Derivation terminals 131 1, 132, ... Are provided respectively. Further, the side wall 121 of the resin case 12 is provided with terminals 141 1, 142, ... Made of metal strips so as to project toward the storage section, and these terminals 141, 142 ,. Terminal 131, 132
, ... Are connected to each other by lead pieces 151, 152 ,.

Here, as shown in FIG.
(141, 142, ...) is the resin case 12 with one end of the metal strip.
It is configured in the form of a cantilever that is embedded and fixed at the time of molding processing of, and the rear surface of this terminal 14, that is, the lead-out terminal 13 (13
Lead pieces 15 (151, 152, ...) connected to 1, 132, ...
16) Holding piece 16 so that it is in contact with the surface opposite to the joining surface
Is provided so that the holding piece 16 can counter the pressure acting from the direction of the joint surface of the lead piece 15 of the terminal 14. In this case, the holding piece 16 is the resin case 12.
At the same time, the same material is molded at the same time.

The resin case 12 has input / output terminals 171, 172.
, ... are integrally provided, and these input / output terminals 171, 1
72 are connected to the terminals 141, 142, ... as appropriate, and the external circuit device and the circuit composed of the circuit board 11 are electrically connected via these input / output terminals 171, 172 ,. Connected.

In the circuit device thus constructed, with the circuit board 11 housed in the housing portion of the resin case 12, lead pieces 151 connected to the lead-out terminals 131, 132, ... Of the circuit board 11, respectively. The respective tips of 152, ... Are superposed on the corresponding terminals 141, 142 ,. And
Similarly to the case described with reference to FIG. 3, the tip of the welding nozzle for laser welding is connected to the lead pieces 151, 152, ...
141, 142, ... Contact each other.

In this case, pressure acts on the terminal 14 from the welding nozzle via the lead piece 15, and this pressure acts on the holding piece 16 that supports the terminal 14, and the holding piece 16 bends the terminal 14. Is prevented from occurring. That is, even when pressure from the welding nozzle is applied during laser welding, the terminal 14 does not bend, and the contact state between the terminal 14 and the lead piece 15 as well as the contact between the joined body and the tip of the welding nozzle. The state is kept stable, the welding by laser light is executed stably,
The reliability of the welding strength is secured.

[0017]

As described above, according to the mounting apparatus for a circuit board according to the present invention, the strength of the metal terminal projecting toward the inner surface of the resin case is ensured, and especially the lead piece is superposed on this terminal. Laser welding etc.
Since the generation of bending is prevented by withstanding the pressure applied from the welding nozzle, the adhesion between the terminal, the lead piece, and the tip of the welding nozzle is reliably maintained during this welding. Therefore, the welding strength between the terminal and the lead piece is secured, and the reliability of this circuit device is improved.

[Brief description of drawings]

FIG. 1 is a plan configuration view showing a state in which a circuit board is mounted in a resin case for explaining an embodiment of the present invention.

2A is an enlarged cross-sectional view of a portion corresponding to the line aa in FIG. 1, and FIG. 2B is a diagram similarly seen from the line bb.

FIG. 3A is a cross-sectional view illustrating a conventional terminal portion of this type, and FIG. 3B is a view illustrating a state in which the welding nozzle is crimped.

[Explanation of symbols]

11 ... Circuit board, 12 ... Resin case, 121 ... Side wall, 13, 131
, 132, ... Lead-out terminal, 14, 141, 142, ... Terminal, 15, 151, 152, ... Lead piece, 16 ... Holding piece, 171,
172, ... Input / output terminals.

Claims (2)

[Claims] 1. A resin case formed by molding a synthetic resin in which a circuit board on which a circuit element is mounted is set, and a side wall portion of the resin case protruding toward a storage portion of the circuit board, A terminal member made of a strip of a conductive material that is integrally embedded and fixed when the resin case is molded, and a terminal provided on the circuit board by being connected to a circuit terminal portion including the circuit element, and a tip thereof is welded to the terminal member. It is provided so as to support a lead piece made of a metal foil to be connected, and a surface of the terminal member opposite to a surface on which pressure is applied when welding the lead piece, and is integrally formed with the resin case at the time of molding. And a pressure applied by a welding nozzle at the time of welding the terminal member and the lead piece to each other. Mounting apparatus of the circuit board that. 2. The circuit board mounting apparatus according to claim 1, wherein the welding of the terminal member and the lead piece is performed by laser welding.