JPH0287594A - Manufacture of hybrid integrated circuit device - Google Patents

Abstract

PURPOSE:To enable externally connecting leads to be soldered to a circuit board efficiently by covering a horizontally extended part adjacent to a clip fitting section of the board with a covering jig formed of a material resistive to solder. CONSTITUTION:In order to solder externally connecting leads to a lead land provided on the periphery of a circuit board, a peripheral region (e) other than the clip fitting section of the board adjacent to clip fitting sections of the leads is covered with a covering jig (f) having a special construction and formed of a special material, namely a material having resistance to solder so that the region (e) is not brought into direct contact with molten solder. Further, heat of the molten solder is prevented from being transferred to soldering sections of components mounted on the board by effect of surface tension. The solder-resistive material unwettable by the solder may be a thermally stable resin such as epoxy glass fiber or bakelite. According to this method, the externally connecting leads can be soldered to the lead land of the circuit board efficiently without the risk of causing the electronic components packaged around the fitting section to fall down because these component are prevented from increase in temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a hybrid integrated circuit device, and more particularly to a method for manufacturing a hybrid integrated circuit device, and more particularly, the soldering of external connection leads to a hybrid integrated circuit board includes special improvements in the method. The present invention relates to a method of manufacturing the circuit device.

[Prior Art] A conventional general manufacturing method for a hybrid integrated circuit device is shown in the order of steps as shown in FIGS. 6a to 6r, and consists of the following steps 1 to 2.

■ A conductor material paste such as Ag-Pd is applied by screen printing to one or both main surfaces of the alumina substrate 1, and baking is processed to form the thick film wiring conductor 2 and the component land 3, and at least After forming lead lands 4 for a plurality of external connection leads on one edge in the same manner as described above so as to connect to the thick film wiring conductor, RuO2 is formed by screen printing so as to connect to the thick film wiring conductor. The thick film resistor 5 is formed by applying a resistive material paste such as the above, and processing the baking process (FIG. 6a).

■ A protective glass is printed by screen printing on the main surface of the thick film circuit board obtained in this manner, excluding the component lands 3 and lead lands 4, and the baking process is performed to form a protective glass layer 6 (Step 6b). figure).

■ After printing solder paste on the component land 3 of the thick film circuit board obtained above, the chip-shaped electronic component 7
, 8.9, etc., and heat-treated in a furnace for reflow soldering, and conductively fixed these electronic components to the component lands by soldering (S) (6th c).

■ Cut grooves 10 are formed using a laser trimming device 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 (6th d
figure).

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

(2) Dip the circuit board into solder so that these lead fitting parts are submerged in the solder 12, and solder the clip parts 11a of the leads to each lead land (Fig. 6r).

■ The hybrid integrated circuit board obtained above is connected to the lead part 11b of the external connection lead 11 and a part of the tie bar.
Except for this part, all other parts are dipped in a moisture-resistant insulating paint such as epoxy resin or phenol resin, and then the insulating resin paint is cured by heat treatment to form a protective film.

(2) A hybrid integrated circuit device is obtained by separating a portion of the tie bar connecting the plurality of external connection leads forming a part of the hybrid integrated circuit on which the protective film has been formed as described above.

[Problems to be Solved by the Invention] However, when manufacturing a hybrid integrated circuit device using the above-mentioned conventional manufacturing method, as shown in FIGS. 4a and 4b, a In the process of soldering clip leads (external connection leads) b to lead lands, the edge of the circuit board is It is necessary to immerse the part into the solder by a certain distance d below the solder liquid level. Therefore, the portion e of the edge of the circuit board that is not a lead land is also submerged under the liquid level of the half 11'J, so naturally this portion e becomes a dead space in which electronic components and the like cannot be mounted. In addition, if electronic components are mounted near the clip fitting part, the soldering of the 7Is child components will be extremely close to the surface of the molten solder. It was possible that some parts would be reheated and the solder in those parts would melt, causing the electronic components to fall out. Therefore, when using the conventional method, as shown in FIG.
Not only must electronic components be mounted so that they do not touch the upper dead space e, but electronic components must be mounted so that they do not touch the dead space boundary (i.e., the solder level is in contact with the surface of the circuit board C). It had to be mounted in a position where it would not be too close to line (line) h.

This is because there is a risk that the solder will be reheated by the heat of the solder and the solder in that area will melt, causing part or all of the solder to 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 certain distance from the boundary line of the dead space. That is, it was not possible to mount electronic components in the dead space shown by e in FIG. 5 and in the parts very close to this. Therefore, especially when high-density mounting is required, an operator may manually solder each of the plurality of external connection leads using a soldering iron to the circuit board on which electronic components are mounted in a separate process. productivity was extremely low.

The purpose of the present invention is to solve the above-mentioned conventional problems, and to not only make it possible to mount electronic components even in areas that conventionally had no choice but to be dead spaces, but also to make it possible to mount electronic components near lead lands and near the solder liquid surface. To provide a method for manufacturing a hybrid integrated circuit device, in which external connection leads can be efficiently soldered to a circuit board without dropping electronic components mounted on the parts.

[Means for solving the problem] When soldering an external connection lead to a lead land normally provided on at least one edge of a circuit board,
During soldering, soldering is carried out on the edges of the external connection leads of the circuit board adjacent to the clip-fitting parts, which are not the clip-fitting parts (i.e., as shown in Figures 1, 2, and 3). The part indicated by e) is covered with a cover (covering jig) f having a special material and structure to prevent this part from coming into direct contact with the molten solder, and the effect of using the cover due to the effect of surface tension The above-mentioned problem was solved by making it difficult for the heat of the molten solder to be transferred to the soldered parts of the components mounted on the circuit board. In the conventional method, the above part e is a dead space where electronic components cannot be mounted, but if the shape and structure of the cover are devised based on the method of the present invention to protect the mounted electronic components, this part e can be An added benefit is that even if electronic parts are mounted on the part, external connection leads can be soldered during the assembly process.

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

After fitting the clip part of the external connection lead to the lead land provided on at least one edge of the circuit board, solder the circuit board to the position where the clip fitting part is fully submerged in the solder. In the method of manufacturing a hybrid integrated circuit device, the method includes the step of soldering the leads to a circuit board by immersing the leads into the circuit board, wherein the soldering is performed by immersing the leads into a clip that becomes an adjacent horizontal extension of the clip-fitting portion of the circuit board during operation. The extended portion that is not the mating portion or at least a wider portion including the extended portion is covered with a covering jig having a substantially U-shaped cross section and made of a solder-resistant material at least on the outer peripheral surface that is difficult to wet with solder. 1. A method of manufacturing a hybrid integrated circuit, which comprises soldering an external connection lead to a lead land provided on a circuit board by dipping the edge of the circuit board into a solder bath.

Epoxy-glass fibers, heat-resistant resins such as Bakelite, etc. can be used as solder-resistant materials that are difficult to get wet with solder for making the coating jig used in the method of the present invention. Also, aluminum, stainless steel, etc. are relatively resistant to solder.

It is also possible to use a hard metal or to apply a dielectric glass paste to the outer peripheral surface of the metal and to treat baking to form a solder resist layer to make it difficult to get wet with solder.

The structure with a substantially U-shaped cross section to be used as a coating jig may be any structure with a substantially U-shaped cross section that can be easily attached to and removed from the edge of the circuit board. (Jet flow) In order to improve the repellency of solder when immersed in a solder bath, it is recommended to provide a flange that guides the solder jet toward the side, as shown in Figures 7 (B) and (C). Effective.

Some examples of coating jigs that can be advantageously used in carrying out the present invention are shown in FIGS.

Preferably, the coating jig is made of a resilient material so that it can be easily attached to the edge of the circuit board and yet remains stable during operation.

Any elastic body that can be conveniently used for this purpose may be any elastic body that is elastic enough to fit around the edge of the circuit board and is resistant to solder, but the resins and metals mentioned above can also be used alone. It is also possible and preferable to arrange silicone rubber on the portion that comes into contact with the circuit board to improve the adhesion to the board.

[Function] When soldering external connection leads to lead lands provided on the edge of a hybrid integrated circuit board according to the present invention, the portions of the edge of the board that are not lead lands are soldered with at least the outer surface resistant to solder. Soldering is performed by covering the covered part with a roughly U-shaped covering jig made of a transparent material, so even this covered part, which conventionally had a deadline, can be soldered.
There is no problem with the mounted electronic components or their soldering even if some parts are present. Contact with molten solder occurs, but since the heat of the solder is blocked by the covering jig, parts of the half date do not re-melt and parts fall off. At least the outer surface of the jig is made of a material that is difficult to wet with solder, so the surface tension of the solder will cause the solder to be repelled from the outer surface of the jig, especially if there is a flange.
For example, the solder liquid level has a shape as shown in Figure 4a,
This is preferable because the heat of the solder is difficult to transfer to the electronic components mounted on the board. Therefore, as shown in FIG. 4b, for example, the range in which the electronic component g can be mounted is expanded to a position extremely close to the edge, and the mounting density can be increased.

Example ■Ag-Pd paste was applied by screen printing on the surface of an alumina substrate 1 as shown in Fig. 6a.
℃ for 10 minutes, and then baked at 850℃ for 10 minutes to form thick film wiring conductors 5, component lands 3, and lead lands 4, and further connected to the thick film wiring conductors by screen printing. Apply RuO2-based resistance paste, dry at 150°C for 10 minutes, and then dry at 850°C for 1
A thick film resistor 5 was formed by baking for 0 minutes.

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

■ After printing solder paste on the component land 3 of the thick film circuit board obtained above, chip-shaped electronic components such as the molded semiconductor 7, chip capacitor 8, and transistor 9 are mounted, and reflow soldering is carried out in a furnace. The electronic components 7, 8, 9, etc. were soldered to the component lands 3 by heat treatment at 230°C.

(2) The resistance value of each of the thick film resistors 5 of the thick film circuit board on which the electronic components were mounted was adjusted using a laser trimming device.

(2) The clip portions of the external connection leads were respectively fitted into the plurality of lead lands 4 on the hybrid integrated circuit board obtained above.

■ A jig made by processing epoxy glass fiber into a substantially U-shaped cross section on the edge portion of the hybrid integrated circuit board where the clip portion of the external connection lead is fitted, other than the lead fitting portion. In the fitted state, the edges of the circuit board were immersed in a flow (jet) solder tank at 235° C., and external connection leads were soldered to the lead lands of the circuit board.

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

In the soldering process described above, electronic components were mounted in positions where they would have come into contact with the solder liquid level when immersed in solder if a coating jig was not used. No inconveniences such as separation due to remelting occur,
The external connection lead could be connected to the lead land extremely well.

[Effects of the Invention] According to the present invention, the clip portion of the external connection lead is fitted to the edge portion of the hybrid integrated circuit board, and the edge portion is immersed in a solder bath to attach the lead to the lead land of the circuit board. When soldering, electronic components mounted around the lead fitting portion are prevented from increasing in temperature, so external connection leads can be efficiently soldered without dropping the mounted components. becomes possible.

In addition, even if electronic components are mounted in areas that were traditionally dead spaces, by attaching a covering jig to protect the components, soldering of external connection leads to lead lands can be made easier. Since the work can be carried out without any trouble, the packaging density can be increased without reducing work efficiency.

[Brief explanation of drawings]

FIGS. 1 and 2 show a hybrid integrated circuit board according to the present invention, in which the edge of the board other than the lead lands is covered with a jig, and the edge is immersed in solder for external connection. FIG. 4 is a conceptual diagram showing the state of contact between the board and solder when connecting the lead to the lead land. FIG. 3 is a three-dimensional perspective view showing a state in which a coating 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 the circuit board on which electronic components are mounted is immersed in solder with the portions other than the lead lands on one edge of the circuit board covered with a jig with a flange. FIG. 4b is a front view of the case of FIG. 4a. FIG. 5 is a front view showing a circuit board immersed in solder without covering the edges of the circuit board with a jig according to the conventional method. FIGS. 6a to 6r 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 advantageously used in the practice of the present invention. The symbols in the figure represent the following, respectively. a...Half 1) b...Clip lead C
...Circuit board d...Solder immersion dimension e...
・Dead space f...Covering jig g...Electronic component h...Boundary line of dead space 1...Alumina substrate 2...Thick film wiring conductor 3.
...Parts land 4...Lead land 5...
Thick film resistor 6... Protective glass layer 7... Molded semiconductor 8... Chip capacitor 9... Transistor [0... Cut groove 11 by laser trimming...
External connection lead LLa...Clip part Llb...
・Lead part 11c...Tie bar part 12...
solder

Claims (1)

[Claims] After fitting the clip part of the external connection lead to the lead land formed on at least one edge of the circuit board, solder the circuit board to the position where the clip fitting part is fully submerged in the solder. In the method of manufacturing a hybrid integrated circuit device, the method includes the step of soldering the leads to a circuit board by immersing the leads in the circuit board, the clip fitting being an adjacent horizontal extension of the clip fitting part of the circuit board during the soldering operation. Covering the extended portion that is not the joint, or at least a wider portion including the extended portion, with a covering jig having a substantially U-shaped cross section and having at least an outer peripheral surface made of a solder-resistant material that does not easily wet with solder. 1. A method of manufacturing a hybrid integrated circuit device, which comprises soldering external connection leads to lead lands provided on a circuit board by immersing an edge of the circuit board in a solder bath.