JP2000196231A - Lead insertion part with bump and bump mounting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To raise hybrid mounting property by providing a lead insertion part with a bump which enables soldering with a plane mounting part at once by a reflow method. SOLUTION: A solder bump 4 is provided in the middle of a lead 3 of a lead insertion part 1. When the part 1 is mounted on a circuit board 5 by inserting the lead 3 to a lead insertion hole 6 of the circuit board 5, the solder bump 4 is pressed to a mouth part of the lead insertion hole 6 and mounting state of the part 1 is stabilized. Then, the solder bump 4 is molten in a reflow furnace and molten solder is made to flow into the lead insertion hole 6, thus fixing the lead 3 to the circuit board 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead insertion component mounted on a circuit board, and more particularly to a lead insertion component with bumps suitable for mixed mounting with a planar mounting component and a method for mounting a bump on the lead.

[0002]

2. Description of the Related Art In order to automatically solder a component to a circuit board, a solder cream is printed and applied to the circuit board, then the component is mounted on the applied portion, and then the solder is heated and melted in a reflow furnace. Various methods such as a reflow method, a flow method in which parts are temporarily fixed to a circuit board, and then a contact point is brought into contact with molten solder, and a soldering method (stationary method) in which solder is supplied to the tip of a heated soldering iron. However, since a bridging phenomenon between electrodes is unlikely to occur and high-density mounting is possible, reflow soldering has been frequently used in recent years.

[0003]

By the way, many circuit boards are mixed boards in which lead insertion components and surface mount components are mixed and mounted. In such a mixed board, the bonding form is different. Further, since the required amount of solder is different, it is impossible to uniformly (commonly) solder the lead insertion component and the surface mount component by the above-mentioned reflow method. Therefore, conventionally, after the surface mounting components are soldered by the reflow method, the lead insertion components are locally soldered by the above-mentioned flow method or the trowel method.

However, in such a mixed mounting method, the lead insertion component and the surface mounting component must be mounted in different processes, so that not only double investment of equipment is required but also the production efficiency is increased due to an increase in man-hours. The decline is inevitable,
Product costs will increase.

After temporarily fixing a surface-mounted component to one side of the circuit board with an adhesive or the like, a lead insertion component is mounted with one side of the component mounted on the lower side, and the leads are protruded on the same one side, and the flow is collectively performed. There is also a method of performing soldering by a method (for example, see Japanese Patent Application Laid-Open No. 9-148725).
Because of the flow system, the problem of the bridge described above remains, and high-density mounting is difficult, and cannot be fundamentally solved.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. It is an object of the present invention to be able to collectively solder a planar mounting component by a reflow method, and thereby to realize a mixed board. It is an object of the present invention to provide a lead-inserted component with a bump which greatly contributes to high density and low cost, and to provide a method for easily mounting a bump on the lead.

[0007]

In order to solve the above-mentioned problems, a lead-inserted component with a bump according to the present invention is characterized in that a solder bump is fixedly provided in the middle of a lead. By providing solder bumps in the middle of the process, simply inserting the lead into the lead insertion hole of the circuit board automatically supplies the required amount of solder to the opening of the lead insertion hole. If inserted and heated, the solder bumps are melted and flow into the lead insertion holes, completing the soldering of the lead insertion component. Therefore, after the solder paste is printed and applied to the circuit board and the surface mount component is mounted, the lead of the lead insertion component with bumps is inserted into the lead insertion hole of the circuit board to fix the position of the component, and then the reflow furnace. If it is inserted, the surface mount component and the lead insertion component can be mixedly mounted at once.

In the present lead-inserted component with bumps, the shape of the solder bump is arbitrary, but it is desirable that the solder bump has a small-diameter portion that can be fitted into the lead insertion hole of the circuit board. Into the lead insertion hole to easily temporarily fix the component.

According to the bump mounting method of the present invention, a jig provided with a plurality of solder pools and provided with a lead insertion hole at the bottom of each solder pool is prepared, solder is first supplied to the solder pool, and then, The solder is heated and melted, the lead of the lead insertion part is inserted into the molten solder, the tip is inserted into the lead insertion hole, and then, after the solder is solidified, the lead is pulled up from the jig. I do.
According to such a mounting method, a large number of leads can be provided with solder bumps at once.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 and 2 show a lead insertion part with bumps according to an embodiment of the present invention. The lead insertion component 1 has a plurality of leads 3 extending downward from the main body 2 and solder bumps 4 fixedly provided. Here, the solder bump 4 has a flat ball shape, and the lead 3 is inserted substantially at the center. The lead 3 of the component 1 usually has a tip 3b whose base 3a is inserted into the lead insertion hole 6 (FIG. 3) of the circuit board 5.
Here, the solder bumps 4 are provided at positions where the upper surface is engaged with a step 3c between the base 3a and the tip 3b (FIG. 2).

In order to mount the present lead insertion component 1 on the circuit board 5, first, as shown in FIG. The component 1 is mounted on the circuit board 5. As described above, the upward movement of the solder bump 4 is restricted by the step 3c in the middle of the lead 3 (FIG. 2). The component 1 is slightly pushed into the mouth, whereby the component 1 is held on the circuit board 5 in a stable posture. Next, the circuit board 5 on which the component 1 is mounted is loaded into a reflow furnace (not shown) and continuously flows through a heating zone and a cooling zone. Then, as shown in FIG. 4, the solder bumps 4 are melted, and the molten solder flows into the lead insertion holes 6 and goes to the back side of the circuit board 5, and at the same time, the component 1 is also lowered by a predetermined amount. 3 is fixed to the circuit board 5 by the solidified solder 7, and the mounting of the lead insertion component 1 is completed.

In FIGS. 3 and 4, the lead insertion hole 6 is shown to be considerably larger in diameter than the width of the lead 3 for convenience of explanation. 3 is smaller than the width of the base 3a of the lead 3, and therefore, at the time of the reflow soldering, the component 1 descends until the step 3c (FIG. 2) of the lead 3 contacts the edge of the lead insertion hole 6, Thereby, the mounting height of the component 1 becomes constant. However, when the lead 3 has a uniform width or when it is desired to change the mounting height of the component 1, for example, a protrusion 3d may be provided in the middle of the lead 3 as shown in FIG. In this case, since the projections 3d prevent the displacement of the solder bumps 4 and function as stoppers for restricting the lower end of the component 1, it is of course possible to mount the component 1 on the circuit board 5 in a stable posture (FIG. 3). , Can be mounted at a fixed height (FIG. 4).

Here, the solder bump provided on the lead 3 may be, for example, a cone-shaped solder bump 4 'gradually narrowed toward the tip end of the lead 3 as shown in FIG. As shown, a two-stage solder bump 4 ″ formed by connecting a large-diameter bump 4a and a small-diameter bump 4b may be used. In this case, the conical-shaped solder bump 4 ′ is sufficiently narrowed, or the two-stage solder bump 4 ′ is formed. By forming the small-diameter bumps 4b of the bumps 4 "so as to fit into the lead insertion holes 6 of the circuit board 5, a part of these solder bumps 4 'and 4" is pressed into the lead insertion holes 6 and the 1 (FIGS. 1 and 2) can be reliably temporarily fixed to the circuit board 5, so that the mounting posture of the component 1 is stabilized and the mounting accuracy is further improved.

Hereinafter, a bump mounting method for mounting the solder bumps 4 on the leads 3 of the lead insertion component 1 will be described. 8 and 9 show one embodiment of the bump mounting method. In this embodiment, a plate-like jig 1 having a plurality of solder pools 11 and a lead insertion hole 12 at the bottom of each solder pool 11 is provided.
Prepare 0. The solder pool 11 is provided on the plate-shaped jig 10 so as to be aligned with a plurality (here, three) of the leads 3 of the lead insertion component 1. The size is large enough to secure the required amount of solder.

At the time of mounting a bump, a predetermined amount of solder 13 is first supplied to a solder pool 11 of a jig 10 as shown in FIG. The form of the solder 13 supplied to the solder pool 11 is arbitrary, and may be, for example, a solid solder ball or a paste-like solder cream. Next, the solder 13 is heated and melted.
As shown in (b), the lead 3 of the component 1 (FIGS. 1 and 2) is inserted into the molten solder 13 by a predetermined length, and the leading end of the lead 3 is inserted through the lead insertion hole 12 toward the rear side of the jig 10. Protrude. Then, in that state, the solder 13 is cooled,
After the solidification (resolidification), the lead 3 is pulled up from the jig 10. Then, the solidified solder sticks to the lead 3 and separates from the jig 10 to form the solder bump 4 as it is.
That is, according to the present bump mounting method, a large number of leads can be provided with solder bumps at once, and a lead-inserted component with bumps can be obtained simply and at low cost.

As the bump mounting method, instead of the above-described method of melting and re-solidifying the solder 13, for example, as shown in FIG.
1 is prepared, and the lead 3 is inserted into the through hole 20.
A method of mechanically caulking the side surfaces of the solder grains 21 as shown by arrows and fixing them to the leads 3, as shown in FIG.
A method of preparing a solder particle 23 having a solder particle 2 and inserting the lead 3 into the slit 22 and then mechanically caulking the side surface of the solder particle 23 as shown by an arrow and fixing the solder particle 23 to the lead 3 May be partially welded to the lead 3.

FIG. 12 shows an example of a mounting process when the lead insertion component with bumps configured as described above is mounted together with a surface mounting component. This mounting process includes a solder printing process A for printing and applying cream solder to the circuit board 30, a surface mounting component mounting process B for mounting the surface mounting component 32 on the solder applied portion 31 of the circuit board 30,
The lead insertion component mounting step C for mounting the lead insertion component 33 with bumps according to the present invention on the circuit board 30 in the above-described manner (FIGS. 3, 4, 6, 7 and the like), and the circuit board 30 on which these components have been mounted. Reflow furnace 35 by conveyor 34
And a reflow soldering process D for passing through the inside and performing reflow soldering.

As described above, when the lead-inserted component with bump 33 according to the present invention is used, mixed mounting can be completed in a series of flows from the solder printing process A to the reflow soldering process D. A mixed board can be manufactured efficiently and at low cost. By the way, conventionally, after mounting the surface mount component 32 on the circuit board 30 through each process of ABD, for example, the lead insertion component is locally soldered by a flow method or a trowel method, Increased manufacturing costs due to double investment of equipment and increase in man-hours were inevitable.

[0020]

As described above, according to the lead-inserted component with bump according to the present invention, since the solder bump is provided in the middle of the lead, it is only necessary to insert the lead into the lead insertion hole of the circuit board. Then, the required amount of solder is automatically supplied to the joint, and soldering can be easily performed by the reflow method. Therefore, even in the case of mounting in a mixed manner with a planar mounting component, soldering can be performed collectively by a reflow method, which greatly contributes to a higher density and a lower cost of the mixed mounting substrate. Further, according to the bump mounting method according to the present invention, it is possible to mount solder bumps on a large number of leads at once using a jig having a solder pool,
The lead insertion component can be easily provided with bumps.

[Brief description of the drawings]

FIG. 1 is a side view showing a partial cross section of a lead insertion component with a bump according to the present invention.

FIG. 2 is an enlarged sectional view showing a coupling structure between a lead and a solder bump.

FIG. 3 is a cross-sectional view showing a mounting state of the present lead insertion component with bump on a circuit board.

FIG. 4 is a cross-sectional view showing a reflow soldering state of the present lead insertion component with bump to a circuit board.

FIG. 5 is a cross-sectional view showing another embodiment of a joint structure between a lead and a solder bump.

FIG. 6 is a cross-sectional view showing a modification of the shape of a solder bump in the lead insertion component with bumps.

FIG. 7 is a sectional view showing another modified example of the shape of the solder bump in the present lead insertion component with bump.

FIG. 8 is a perspective view showing an embodiment of a bump mounting method.

FIG. 9 is a sectional view illustrating an embodiment of a bump mounting method in the order of steps.

FIG. 10 is a perspective view showing another embodiment of the bump mounting method.

FIG. 11 is a perspective view showing still another embodiment of the bump mounting method.

FIG. 12 is a schematic view showing a process of mixed mounting when using the lead component with bumps.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 lead insertion type electronic component 2 main body 3 lead 4 solder bump 5 circuit board 6 lead insertion hole 7 solder 10 bump mounting jig 11 solder pool 12 lead insertion hole

Claims (3)

[Claims] 1. A lead-inserted component with bumps, wherein solder bumps are fixed in the middle of the leads. 2. The lead-inserted component with bump according to claim 1, wherein the solder bump has a small-diameter portion that can be inserted into a lead insertion hole of the circuit board. 3. A jig having a plurality of solder pools and a lead insertion hole at the bottom of each solder pool is prepared. First, solder is supplied to the solder pool, and then the solder is heated and melted. Inserting the lead of the lead insertion component into the molten solder, inserting the tip of the lead into the lead insertion hole, and then pulling up the lead from the jig after the solidification of the solder.