JPH0756911B2 - Method for manufacturing hybrid integrated circuit device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a hybrid integrated circuit device, and more particularly to a method for soldering an external connection lead to a hybrid integrated circuit board, which includes a special improvement. The present invention relates to a method for manufacturing a circuit device.

[Prior Art] A general method for manufacturing a conventional hybrid integrated circuit device is shown in the order of steps as shown in FIGS. 6a to 6f, and includes the following steps.

A thick film wiring conductor 2 and a component land 3 are formed by applying a conductor material paste such as Ag-Pd on one or both main surfaces of the alumina substrate 1 by screen printing and baking it, and at least one edge of the alumina substrate 1 The lead lands 4 of the leads for external connection are formed in the same manner as described above so as to be connected to the thick film wiring conductors, respectively, and then screen printed so as to connect to the thick film wiring conductors
A resistive material paste such as RuO ₂ is applied and baked to form a thick film resistor 5 (FIG. 6a).

Protective glass is printed by screen printing on a portion of the main surface of the thick film circuit board thus obtained excluding the component lands 3 and the lead lands 4 and baked to form a protective glass layer 6 (FIG. 6b).

After printing the solder paste on the component land 3 of the thick film circuit board obtained as described above, the chip-shaped electronic component 7,
8 and 9 etc. are mounted and heat treated in a reflow soldering furnace to electrically conductively fix these electronic components to the component land by soldering (S) (Fig. 6c).

A laser trimming device is used to form a kerf 10 in each thick film resistor 5 formed on the thick film circuit board on which the above electronic components are mounted to adjust the resistance value (6d).
Figure).

The clip portions 11a of the external connection leads 11 are fitted into the plurality of lead lands provided on the hybrid integrated circuit board obtained as described above (Fig. 6e).

The circuit board is dipped in the solder so that the lead fitting portions are immersed in the solder 12, and the lead clip portions 11a are soldered to the lead lands (FIG. 6f).

The hybrid integrated circuit board obtained as described above, except for the lead portion 11b and the tie bar portion 11c of the external connection lead 11, all the other parts to an insulating coating having a moisture resistance such as epoxy resin or phenol resin. After dipping, the insulating resin coating material is cured by heat treatment to form a protective film.

From the plurality of external connection leads forming part of the hybrid integrated circuit on which the protective film is formed as described above, the tie bar portion 11c connecting them is cut off to obtain the hybrid integrated circuit device.

[Problems to be Solved by the Invention] However, when a hybrid integrated circuit device is manufactured by the conventional manufacturing method described above, as shown in FIG. 5, a clip is formed on a lead land provided on an edge portion of the hybrid integrated circuit board c. In the process of soldering the lead (external connection lead) b, the edge portion of the circuit board is being soldered so that the fitting portion of the clip lead fitted to the lead land is submerged below the liquid surface of the solder a. It is necessary to immerse the solder in a certain distance d from the solder liquid surface. Therefore, in the edge portion of the circuit board, the portion e which is not the lead land is also submerged below the liquid surface of the solder, and this portion e naturally becomes a dead space in which electronic parts and the like cannot be mounted. Not only that, when electronic parts are mounted near the clip fitting part, the soldered part of the electronic part comes very close to the liquid surface of the molten solder, so that the soldered part is re-attached. It may happen that the solder in the portion is heated and the electronic component falls down. Therefore, in the case of the conventional method, for example, when mounting the electronic component g, not only the soldering portion must be mounted so as not to reach the dead space e on the circuit board c, but also the soldering portion of the electronic component is mounted. Had to be mounted at a position that did not come too close to the boundary line of the dead space (that is, the line formed by the liquid surface of the solder in contact with the surface of the circuit board c).

This is because there is a risk that the solder will be reheated by the heat of the solder and the solder in that portion will melt and part or all of the soldering will separate from the component land. Therefore, in the case of the conventional method, as illustrated in FIG. 5, for example, the electronic component g had to be mounted at a position separated from the boundary h of the dead space to some extent. That is, electronic parts could not be mounted on the dead space shown in FIG. 5e and the part very close thereto.
Therefore, especially when high-density mounting is required, an operator manually solders the plurality of external connection leads to a circuit board on which electronic components are mounted by using a soldering iron in separate steps. It had to be done and productivity was extremely low.

An object of the present invention is to solve the above-mentioned conventional problems and not only to mount an electronic component in a portion that has conventionally been forced to become a dead space, but also to be near a lead land or a liquid surface of solder. An object of the present invention is to provide a method for manufacturing a hybrid integrated circuit device capable of efficiently soldering an external connection lead to a circuit board without dropping an electronic component mounted on a part thereof.

[Means for Solving the Problem] When soldering the external connection lead to the lead land usually provided on at least one edge portion of the circuit board,
An edge portion (that is, e in FIGS. 1, 2, and 3) that is a horizontal extension portion adjacent to the clip fitting portion of the external connection lead of the circuit board during the soldering work and is not the clip fitting portion. Is covered with a cover (coating jig) f having a special material and structure so that this part does not come into direct contact with the molten solder, and melting is performed by the effect of using the cover due to the action of surface tension. The heat of the solder has been devised so that it is less likely to be transferred to the soldering portion of the mounted component on the circuit board, and by doing so, the above-mentioned problems can be solved. The above-mentioned part e is a dead space in which electronic parts cannot be mounted by the conventional method, but if the shape and structure of the cover is devised based on the method of the present invention to protect the mounted electronic parts, this e Even if an electronic component is mounted on the portion, there is an added benefit that the lead for external connection can be soldered in a flow work process.

The method of the present invention described above can be summarized as follows.

After fitting the clip part of the lead for external connection to the lead land provided on at least one edge of the circuit board, solder the circuit board to a position where the clip fitting part is sufficiently immersed in the solder. In a method of manufacturing a hybrid integrated circuit device, which comprises a step of immersing the leads in a circuit board and soldering the leads to the circuit board, a clip fitting to be an adjacent horizontal extension portion of the clip fitting portion of the circuit board during soldering work. The extended portion that is not a joint portion or a wider portion including at least the extended portion is formed in a direction perpendicular to the main surface direction of the circuit board, at least the outer peripheral surface of which is made of a solder-resistant material that is difficult to wet with solder. Externally connected to a lead land provided on the circuit board by covering the edge of the circuit board in a solder bath with a covering jig having a U-shaped cross section with a flange. Method for manufacturing a hybrid integrated circuit, characterized by soldering the leads.

The coating jig used in the above manufacturing method can be summarized as follows.

In order to cover any part of the circuit board during soldering work, the outer peripheral surface is made of a solder-resistant material that does not easily get wet with solder, and its cross section is approximately U-shaped. On the other hand, a covering jig for dip soldering is characterized in that it has a flange portion that protrudes vertically.

As the solder-resistant material which is hard to be wetted by the solder for forming the coating jig used in the method of the present invention, epoxy-glass fiber, heat-resistant resin such as Bakelite, or the like can be used. It is also possible to use a metal such as aluminum or stainless steel which is relatively hard to wet with solder, or to apply a dielectric glass paste on the outer peripheral surface of the metal and form a solder resist layer by baking to make it hard to get wet with solder. it can.

The structure having a substantially U-shaped cross section used as a covering jig has a substantially U-shaped cross section that can be easily attached to and detached from an edge portion of a circuit board and has a flow (jet) solder. In order to improve the repulsion of the solder when immersed in the bath, as shown in FIGS. 7B and 7C, it is characterized in that a flange portion for guiding the jet of the solder in the lateral direction is provided. . Some examples of coating jigs that can be conveniently used for carrying out the present invention are shown in FIGS. 7 (a) to 7 (b).

The covering jig is preferably made of an elastic material so that it can be easily attached to the edge of the circuit board and is stably held during the work. Any elastic body that can be conveniently used for this purpose may be used as long as it is solder-resistant and has elasticity that can be fitted to the edge portion of the circuit board. It is also possible and preferable to arrange a silicone rubber in a portion that comes into contact with the circuit board to improve the adhesion to the board.

[Operation] When soldering the external connection lead to the lead land provided on the edge portion of the hybrid integrated circuit board according to the present invention, at least the outer surface of the edge portion of the board edge which is not the lead land is resistant to soldering. Since soldering is performed by covering with a jig for covering with a substantially U-shaped cross section having the above-mentioned brim section made of the above material, soldering is also performed on this covered part which was a dead line in the past. , Even if there is a mounted electronic component or its soldering part, it does not matter. This is because contact with the molten solder does not occur, and the heat of the solder is also blocked by the coating jig, so that the soldered portion does not remelt and the component does not drop off. At least the outer surface of the jig is made of a material that does not easily get wet with the solder, so the solder is repelled from the outer surface of the jig by the surface tension of the solder, and there is a collar, so that the liquid surface of the solder is As shown in the figure, the heat of the solder is less likely to be transferred to the electronic components mounted on the substrate. Therefore, for example, as shown in FIG. 4b, the mountable range of the electronic component g is expanded to a position extremely close to the edge portion, and the mounting density can be increased.

Example An Ag-Pd paste was applied to the surface of an alumina substrate 1 as shown in FIG. 6a by screen printing, dried at 150 ° C. for 10 minutes, and then baked at 850 ° C. for 10 minutes to form a thick film wiring conductor 2 and components. The land 3 and the lead land 4 are formed,
Further, a RuO ₂ series resistance paste was applied by screen printing so as to be connected to the thick film wiring conductor, dried at 150 ° C. for 10 minutes, and then baked at 850 ° C. for 10 minutes to form a thick film resistor 5.

A protective glass is printed on the surface of the thick film circuit board thus obtained other than the component land 3 and the lead land 4 by screen printing and dried at 150 ° C. for 10 minutes, and then 530
The protective glass layer 6 was formed by baking at 2 ° C. for 2 minutes.

After printing the solder paste on the component land 3 of the thick film circuit board obtained above, chip-shaped electronic components such as the mold type semiconductor 7, the chip capacitor 8 and the transistor 9 are mounted, and the reflow soldering furnace The electronic components 7, 8 and 9 were soldered to the component land 3 by heat treatment at ° C.

The resistance value of each of the thick film resistors 5 of the thick film circuit board on which the electronic component is mounted was adjusted by a laser trimming device.

Clip portions of leads for external connection were fitted to the lead lands 4 on the hybrid integrated circuit board obtained above.

An epoxy-glass fiber is processed to have a U-shaped cross section having a collar portion at a portion other than the lead fitting portion of the edge portion where the clip portion of the lead for external connection of the hybrid integrated circuit board is fitted. With the jig fitted, the edge portion of the circuit board was immersed in a flow (jet) solder bath at 235 ° C. to solder the lead for external connection to the lead land of the circuit board.

The jig was removed from the edge of the hybrid integrated circuit board.

In the above soldering, the electronic component was also mounted at a position where the electronic component should come into contact with the solder liquid surface when immersed in the solder unless a coating jig is used. Inconvenience such as separation due to remelting does not occur at all,
The connection of the lead for external connection to the lead land could be performed extremely well.

[Effects of the Invention] According to the present invention, the clip portion of the lead for external connection is fitted to the edge portion of the hybrid integrated circuit board, and the edge portion is immersed in the solder bath so that the lead becomes a lead land of the circuit board. When soldering, since the temperature rise of the soldering part of the electronic component mounted around the lead fitting part is prevented, it is possible to efficiently solder the external connection lead without dropping the mounted component. Is possible.

In addition, even if molecular parts are mounted in the parts that used to be dead spaces in the past, soldering the external connection leads to the lead lands can be performed by attaching a coating jig to protect the parts. Since the work can be performed without any trouble, the mounting density can be increased without lowering the work efficiency.

[Brief description of drawings]

1 and 2 show, according to the present invention, a portion of a hybrid integrated circuit board edge portion other than a lead land is covered with a coating jig, and the edge portion is dipped in solder to lead an external connection lead. It is a conceptual diagram which shows the contact state of the board | substrate and solder when connecting to a land. FIG. 3 is a three-dimensional perspective view showing a state in which a bridging jig is attached to the edge of the circuit board and the edge is immersed in solder. FIG. 4a is a side view showing a state in which one edge portion of the circuit board on which the electronic component is mounted, other than the lead lands, is covered with a jig having a collar and the circuit board is immersed in solder. FIG. 4b is a front view of the case of FIG. 4a. FIG. 5 is a front view showing a state in which the board is immersed in solder without covering the edge portion of the circuit board with a jig according to the conventional method. 6a to 6f show a typical conventional method for manufacturing a hybrid integrated circuit device in the order of steps. FIG. 7 is a perspective view of several examples of coating jigs that can be conveniently used for implementing the present invention. The symbols in the figure represent the following respectively. a ... Solder, b ... Clip lead c ... Circuit board, d ... Solder immersion dimension e ... Dead space, f ... Coating jig g ... Electronic parts h ... Boundary of dead space 1 ... ... Alumina substrate, 2 ... Thick film wiring conductor 3 ... Part land, 4 ... Lead land 5 ... Thick film resistor, 6 ... Protective glass layer 7 ... Mold type semiconductor, 8 ... Chip capacitor 9 ... … Transistor 10 …… Cutting groove by laser trimming 11 …… External connection lead, 11a …… Clip part 11b …… Lead part, 11c …… Tie bar part 12 …… Solder

Claims (2)

[Claims] 1. After fitting a clip portion of a lead for external connection to a lead land formed on at least one edge portion of a circuit board, the clip fitting portion is sufficiently immersed in solder. In a method for manufacturing a hybrid integrated circuit device including a step of immersing a rotating substrate in solder to a position and soldering the leads to a circuit board, at least a horizontal extension of the circuit board adjacent to the clip fitting portion in the circuit board during soldering work. The outer peripheral surface of the portion is made of a solder-resistant material that is hard to be wetted by solder, and the outer peripheral surface has a flange portion that projects in a direction perpendicular to the main surface direction of the circuit board, and has a substantially U-shaped cross section. A method for manufacturing a hybrid integrated circuit device, comprising: soldering an external connection lead to a lead land by covering the circuit board with a die coating jig and immersing the circuit board in a solder bath perpendicularly to the solder surface. 2. A dip soldering coating jig for coating an arbitrary edge portion of a circuit board during a soldering operation to immerse the circuit board in the solder perpendicularly to the solder surface,
At least the outer peripheral surface is made of a solder-resistant material that is hard to be wetted by solder, and has a substantially U-shaped cross section, and the outer peripheral surface has a collar portion protruding in a direction perpendicular to the main surface direction of the circuit board. A coating jig for dip soldering.