JPH0413476A - Soldering device - Google Patents

Abstract

PURPOSE:To stick solder only to the required parts of a work by providing recessed parts which do not come into contact with the work at specified intervals in a circumferential direction. CONSTITUTION:The band-shaped work mounted with semiconductor chips 15 on one surface is transported in the upper direction of the device while the work is brought into contact with a pair of soldering rollers 5 and 5 which rotate face to face each other, when the soldering device is operated. Since the recessed parts 14 formed on the peripheral surfaces 13 of the rollers 5 are formed by being stepped from the peripheral surfaces 13 at the depth to accommodate the semiconductor chips 15, the soldering rollers 5 do not come into contact with the parts corresponding to the recessed parts 14 centering at the semiconductor chips 15. On the other hand, the rollers 5 come into contact with the parts exclusive of the parts corresponding to the recessed parts 14 and the molten solder is transferred. The molten solder is transferred in four ways so as to enclose the semiconductor chips 15 in this way. Consequently, the molten solder is simultaneously stuck to the lead forming parts of the four ways enclosing the semiconductor chips 15 of the work for production of the semiconductor devices of a quad type.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a soldering device that continuously applies molten solder to a strip-shaped or strip-shaped lead frame.

[Conventional technology]

Electronic devices such as transistors are generally manufactured by sequentially performing steps such as chip bonding, wire bonding, resin mounting, soldering to leads, and tie bar cutting on a lead frame. Recently, in order to improve manufacturing efficiency, instead of the conventional strip-shaped lead frame, a long strip-shaped lead frame is used, and this is continuously conveyed. However, a manufacturing method in which each process is performed sequentially is becoming widespread. Various soldering devices for soldering such workpieces have already been proposed, and the applicant of the present application has also proposed one shown in Japanese Patent Laid-Open No. 63-290689, for example. ing. The present invention is based on a soldering device having such a conventional configuration, and its basic configuration will be explained with reference to FIG. 1. Note that FIG. 1 shows an example of a soldering device that solders a strip-shaped workpiece. This type of soldering device 1 includes a solder storage tank 2 in which molten solder S is stored, and within this solder storage tank 2,
a jet flow forming means 3 for forming a jet flow of the molten solder S; a soldering roller 5 which rotates while being partially immersed in the jet flow of the molten solder S and rotates in synchronization with the feeding of the strip-shaped workpiece 4; , and a workpiece conveyance device 6 that conveys the workpiece 4 at a predetermined speed. The jet forming means 3 includes a jet forming cylinder 8 disposed in the solder storage tank 2 such that the open lower part projects above the solder liquid level 19, and a jet forming cylinder 8 arranged in the jet forming cylinder 8 toward the open lower part. A pump 9 for forming a solder flow is provided. The soldering roller 5 contacts the jet of the molten solder S and transfers the molten solder S attached to the circumferential surface onto the strip-shaped workpiece 4 without rolling. In this way, continuous soldering is performed on the strip-like workpiece 4. Note that the soldering device l shown in FIG.
1 is constructed so that soldering can be performed on both sides of the strip-like workpiece 4 at the same time. By employing the soldering device 1 described above, it is possible to automatically and continuously solder terminal portions corresponding to a large number of electronic devices, and production efficiency can be dramatically increased.

[Invention or problem to be solved]

Incidentally, recently, in order to reduce the size and improve the performance of electronic devices, high-performance semiconductor devices having many glued terminals have been manufactured. The above-mentioned multi-terminal semiconductor device is usually a so-called quad type semiconductor device in which lead portions extend from all sides of the package, and the lead portions extending in all directions must be soldered as described above. . However, with the conventional soldering apparatus described above, it is not possible to simultaneously solder the lead forming portions on all four sides of a workpiece for manufacturing the quad type semiconductor device. That is, as shown in FIG. 6, a soldering roller 5a in a conventional semiconductor device has an outer circumferential groove 18 formed in the center of its circumferential surface 13 in which a semiconductor chip 15 can be accommodated. Both sides 5b of 5a, 5b
It is formed so as to contact and rotate along the inner side of both side edges 4a, 4a of the strip-like workpiece 4. Therefore, the soldering roller 5a can only apply solder to the portions along both side edges 4a, 4a of the strip-like workpiece 4. For this reason, in a workpiece for manufacturing a quad-type electronic device, it is impossible to solder the lead terminal forming portion extending from the semiconductor chip 15 in the feeding direction (direction perpendicular to the plane of the paper in FIG. 6). be. For this reason, for workpieces that manufacture quad-type semiconductor devices, as has been done in the past,
Soldering must be performed by dipping the entire workpiece in molten solder, making it impossible to increase productivity. Furthermore, if the entire workpiece 4 is immersed in the molten solder S, the heat of the molten solder may be directly transmitted to the semiconductor chip 15 and have an adverse effect, resulting in a problem that the reliability of the product is reduced. Furthermore, the conventional soldering apparatus can only perform band-shaped soldering along both side edges 4a, 4a of the workpiece 4, and excess solder adheres to areas other than the leat forming portion. Therefore, there is a problem in that the amount of solder used increases more than necessary, which increases manufacturing costs. The present invention has been devised under the above-mentioned circumstances, and solves the above-mentioned conventional problems, and enables simultaneous soldering around quad-type semiconductor chips, etc. The object is to provide a soldering device that can apply solder only to necessary parts.

[Means for Solving the Problems] In order to solve the above problems, the present invention takes the following technical means. That is, the present invention provides a soldering device that includes a workpiece conveyance device that conveys a workpiece at a predetermined speed, and a soldering cooler that is rotated in contact with the workpiece and continuously applies molten solder supplied to the circumferential surface of the workpiece. The soldering device is characterized in that concave portions that do not contact the workpiece are provided on the circumferential surface of the soldering roller at regular intervals in the circumferential direction. Effects and Effects of the Invention The concave portion formed on the circumferential surface of the soldering roller of the soldering device according to the present invention is stepped to the circumferential surface of the soldering roller so as not to contact the surface of the workpiece. is formed. Therefore, molten solder is not transferred onto the workpiece that is in contact with the recessed portion. On the other hand, the circumferential surface of the soldering roller other than the recessed portion rotates in contact with the workpiece, and the molten solder is transferred to the workpiece at that portion. When the recessed portion is formed in a shape and depth capable of accommodating a semiconductor chip protruding from the surface of the workpiece, and the workpiece and the soldering roller are rotated synchronously,
Solder on the four peripheries surrounding the semiconductor chip.
The circumferential surface of the solder comes into rotational contact, making it possible to transfer the molten solder to all four sides of the semiconductor chip. As a result, it becomes possible to simultaneously attach molten solder to the groove forming portions extending in all directions of a quad type semiconductor chip. Therefore, by employing the soldering apparatus according to the present invention, the production efficiency of quad-type semiconductor devices can be dramatically improved. Furthermore, in the soldering apparatus according to the present invention, the molten solder and the soldering roller do not come into contact with the semiconductor chip mounted on the workpiece, so no heat is applied to the semiconductor chip. This greatly improves the reliability of the product compared to the conventional method of immersing the entire workpiece in molten solder for soldering. Further, since the recessed portion can be formed into a desired shape, it becomes possible to solder only to a predetermined portion. Therefore, it is possible to apply solder only to necessary parts such as the lead forming portion of the workpiece, and the amount of solder used can be reduced, thereby reducing manufacturing costs.

[Explanation of Examples]

Embodiments of the present invention will be specifically described below with reference to FIGS. 1 to 5. FIG. 1 is a sectional view schematically showing a soldering device according to the present invention. As shown in this figure, the soldering device 1 of this embodiment is
a solder storage tank 2 for storing molten solder S; a jet forming means 3 for forming a jet of molten solder S in the solder storage tank 2; It also includes a soldering roller 5 that applies solder to the strip-shaped work 4, and a work conveyance device 6 that conveys the work 4. In the embodiment shown in FIG. 1, a unit consisting of the solder storage tank 2, jet flow forming means 3, and soldering roller 5 is used to solder both sides of the strip-like workpiece 4 at the same time. There are a pair of machines on the left and right sides of the transport route. The jet forming means 3 includes a jet forming cylinder 8 disposed in the solder storage tank 2 with an open lower part protruding above the liquid surface 19 of the molten solder S, and a jet forming cylinder 8 into which suction is drawn from the lower part. It is configured to include a pump 9 that sends molten solder S toward the open lower part. This pump 9 is connected to the lower suction port 1 of the jet flow forming cylinder 8.
An impeller 11 is provided inside the 0, and the impeller 11 is rotated by a motor 12. When the pump 9 is driven, either the molten solder S flows in the jet flow forming cylinder 8 toward the lower part, or the molten solder S is ejected in an overflow form from the open lower part, and the molten solder S is always in a fluid state. be done. The soldering roller 5 rotates while its lower part is immersed in the jet of the molten solder S. As described above, by bringing the molten panda S in a jet state into contact with the soldering roller 5, the liquid level 19 of the solder storage tank 2 is
By varying the amount of molten solder S, it is possible to maintain a constant amount of molten solder S adhering to the soldering roller 5, and to prevent solder oxide from adhering to the soldering roller 5 or the workpiece 4. As shown in FIG. 2, the soldering roller 5 in this embodiment is an integrally molded product having a short columnar shape, and has rectangular recesses 14 formed on its circumferential surface 13 at regular intervals in the circumferential direction. There is. The recesses 14 are formed at regular intervals in the circumferential direction at intervals corresponding to the pitch of the semiconductor chips 15 mounted on the workpiece 4, and have a depth that can accommodate the semiconductor chips 15 mounted on the surface of the workpiece 4. is set to . Then, the soldering roller 5 moves the workpiece 4 so that the semiconductor chip 15 corresponds to the concave portion 14.
It is rotated in synchronization with the conveyance speed. As shown in FIG. 1, the workpiece conveyance device 6 has a conveyance path set so that the strip-shaped workpiece 4 is moved in the vertical direction while being sandwiched between the pair of left and right soldering rollers 5, 5. The device is equipped with a pair of guide rollers 20, 20 and feed rollers 21, 21, and conveys the strip-like workpiece 4 upward in the device at a predetermined speed. When the soldering apparatus l having the above configuration is operated, as shown in FIG. is conveyed upward through the device while making contact with the As shown in FIG. 3, the recessed portion 14 formed on the circumferential surface 13 of the noering roller 5 according to this embodiment is stepped from the circumferential surface 13 to a depth that can accommodate the semiconductor chip 15. Since the semiconductor chip 15 of the work 4 is
The soldering roller 5 does not come into contact with the portion corresponding to the concave portion 14 centered at . On the other hand, the recessed portion 1
The soldering roller 5 contacts the portion other than the portion corresponding to 4, and the molten solder S is transferred. Therefore, the molten solder S can be transferred to all sides so as to surround the semiconductor chip 15. As a result, it becomes possible to simultaneously attach the molten solder S to the four lead forming portions surrounding the semiconductor chip 15 of a workpiece for manufacturing a quad-type semiconductor device. Therefore, by introducing the soldering apparatus l according to the present invention into a quad-type semiconductor device manufacturing line, the production efficiency of the line can be dramatically improved. Further, in the soldering apparatus 1 according to the present embodiment, as shown in FIG. 3, the molten solder S and the soldering roller 5 do not come into contact with the semiconductor chip 15 mounted on the workpiece 4. Therefore, the heat of the molten solder S is not directly applied to the semiconductor chip 15 and has no adverse effect, and the reliability of the product is improved compared to the conventional method of immersing the entire workpiece 4 in molten solder. Much improved. Furthermore, since the recessed portion 14 in this embodiment can be formed into a desired shape, soldering can be performed only at predetermined locations. Therefore, it is also possible to apply solder only to the parts of the workpiece 4 that require soldering. As a result, the amount of solder used can be reduced,
Manufacturing costs can also be reduced. The scope of the present invention is not limited to the above-described embodiments. The soldering roller 5 in the above embodiment is an integrally molded product having a recessed portion 14 formed on its circumferential surface.As shown in FIGS. 4 and 5, the recessed portion 14 is configured A soldering roller 18 is constructed by overlapping a disc 16 with U-shaped notches 14a formed on its outer periphery at regular intervals, and a pair of discs 17°17 attached to both sides of the disc 16, or another method. It is also possible to employ a soldering roller formed of. Furthermore, in the embodiment, the pair of soldering rollers 5, 5 are simultaneously pressed against both sides of the strip-shaped workpiece 4 to perform soldering, but soldering is performed only on one side of the strip-shaped workpiece 4. In this case, the soldering device according to the present invention can be similarly applied. In this case, the soldering roller 5 will be placed only on one side of the workpiece 4, and the backup roller will be placed on the opposite side. Further, in the embodiment, a jet stream was used to supply the molten solder S to the soldering roller 5, but by simply immersing the lower part of the soldering roller 5 in the liquid surface of the molten solder S, the soldering roller 5 The present invention can also be applied to a soldering device that supplies molten solder S to the peripheral surface 13 of. Further, in this embodiment, the present invention is applied to a soldering device l that solders a strip-shaped workpiece 4, but it can be applied to a soldering device l that solders a workpiece such as a conventional strip-shaped lead frame. The present invention can also be applied.

[Brief explanation of the drawing]

FIG. 1 is a sectional view schematically showing the soldering device of the present invention, FIG. 2 is an external perspective view of the soldering roller of the soldering device of the present invention, and FIG. 3 explains the operation of the soldering roller. FIG. 4 is an external perspective view showing another embodiment of the present application, FIG. 5 is a partial sectional view taken along the line ■-V in FIG. 4, and FIG. 6 is a part of a conventional soldering device. FIG. ■...Soldering device, 4...Work, 5...Soldering roller, 13...Surrounding surface, 14...Concave portion.

Claims (1)

[Claims] (1) A workpiece transport device that transports the workpiece at a predetermined speed;
A soldering device comprising a soldering roller that is rotated in contact with the workpiece and continuously applies molten solder supplied to the workpiece on the circumferential surface, wherein the circumferential surface of the soldering roller does not come into contact with the workpiece. A soldering device characterized in that concave portions are provided at regular intervals in the circumferential direction.