JPH0442059Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a jet solder bath for soldering printed circuit boards by roughening the waves of jetting molten solder.

[Conventional technology]

In the past, electronic components had long leads, and the leads were soldered to the printed circuit board by inserting these long leads into holes in the soldering area of the printed circuit board and dipping them in molten solder. Ta. When electronic components having long leads can be soldered simply by immersing them in molten solder, there is hardly any unsolder that does not adhere to the soldered parts.

However, electronic components without long leads (hereinafter referred to as leadless components), which are becoming more commonly used today, are attached directly to a printed circuit board with adhesive and then dipped in a jet of molten solder for soldering. As a result, the soldered portion between the printed circuit board and the leadless component becomes a corner, and flux frames and air remain in the corner, preventing molten solder from penetrating, resulting in unsoldered parts. In order to eliminate this unsolder, it is known that by roughening the waves of the jet solder in which the printed circuit board is immersed, the rough waves penetrate into the corners and eliminate the unsolder.

A number of devices have been proposed to disrupt the waves of jet solder, but they can be broadly divided into those that use power and those that do not require power and disrupt the waves with the jet of molten solder itself.

Products that use power for rough seas not only have a complicated structure, but also have to be installed near high-temperature molten solder. The oxide of the molten solder sometimes gets stuck in the rough areas, causing problems such as making movement difficult.

On the other hand, jet solder baths that do not use power to create waves have a simple structure, do not have the problems of jet solder baths that use power, and have the advantage of producing stable waves for a long period of time.

The applicant of the present invention has developed a jet soldering tank that does not use power by installing a floating body in a nozzle, holding both ends of the floating body with a tension spring, and shaking the floating body with the force of the jetted molten solder. In Japanese Patent Application No. Sho 62-100591 (Japanese Patent Publication No. 1-59073), we proposed a jet solder tank that disrupts solder waves (hereinafter referred to as a tension spring floating body type jet solder tank). [Problem that the invention aims to solve] A spring floating body type jet solder bath can greatly roughen the waves of molten solder, and is therefore very effective in soldering printed circuit boards equipped with a large number of leadless components. However, with printed circuit boards that have a small amount of leadless electronic components, solder-free soldering can still be performed even if the waves are not too large and rough, but in a tension spring floating body type jet soldering bath, the roughness of the waves can be extremely reduced. I was unable to do this, so I used to solder in waves that were rougher than necessary.

Incidentally, when the waves in the jet solder bath become rough, the molten solder comes into contact with air in a larger area, and the amount of oxidized molten solder increases. Therefore, as mentioned above, when soldering a printed circuit board with a small number of leadless components mounted, if soldering is performed with unnecessarily rough waves, a large amount of oxides will be generated.

An object of the present invention is to provide a jet solder bath that does not use power and can appropriately adjust the roughness of waves according to the state of mounting components on a printed circuit board.

[Means to solve the problem]

The inventor proposed that in order to reduce the spring action with a tension spring, the spring must be stretched long until it becomes a straight line, but with a compression spring, this can be done by narrowing the distance between the springs, and moreover, the spring action can be completely reduced. This invention was completed by focusing on the fact that it is extremely easy to eliminate.

The present invention involves drilling a hole in the side plate of the nozzle, inserting a floating body into the hole, attaching a spring holder to both ends of the floating body, and installing a compression spring between the spring holder and the side plate. This is a characteristic jet soldering bath.

〔Example〕

The jet solder bath of the present invention is composed of a pair of nozzle plates 2 and 3 with a nozzle 1 and side plates 3 and 3 installed on both sides of the nozzle plate. The side plate 3 is divided into an upper part and a lower part, and the upper side plate 3a is fixed to the lower side plate 3b with bolts 4. Upper side plate 3
The bolt insertion hole 5 of a is horizontally long, and the upper side plate 3a is movable within this horizontally long hole. Both side plates 3, 3 are provided with holes 6, 6, and a floating body 7 having a diameter smaller than that of the hole 6 is inserted through the hole 6. Spring holders 8, 8 are provided at both ends of the floating body 7.
is installed. The spring holder shown in FIGS. 1 to 3 is a cap nut. One spring holder is fixed to the floating body 7, and the other spring holder is screwed to the floating body so that the mounting position can be adjusted, and a lock nut is provided on the outside of the adjustable spring holder. 9 are screwed together. A compression spring 10 is installed between the spring holder 8 and the side plate 3 and applies a force in a direction to separate the spring holder and the side plate. FIG. 4 shows another embodiment, in which a nut is used as the spring holder.

Next, the state of the jet flow in the jet solder bath of the present invention will be explained.

When molten solder S is jetted from a nozzle using a jet pump (not shown), the molten solder hits the floating body 7 in the nozzle, and the floating body vibrates as shown by the dashed line in FIG. 2 due to the force of the jet. When the floating body vibrates in the nozzle, the waves of the jetting molten solder become rough, and when soldering a printed circuit board with leadless components mounted, the molten solder seeps into the corners of the leadless components, causing flux fumes and Eliminates unsolder by expelling residual air. At this time, if the vibration of the floating body is large, the roughness of the waves will be large, and if the vibration of the floating body is small, the roughness of the waves will be small. The vibration of the floating body can be made in any way by adjusting the mounting position of the compression spring that holds the floating body. In other words, when the spring holder is moved away from the side plate, the compression spring stretches, and the holding force of the floating body becomes weaker, causing the floating body to vibrate greatly, making the wave of the jet solder greatly rough. Also, when the spring holder is moved closer to the side plate, the compression spring is compressed. As the spring contracts, the holding force of the floating body becomes stronger, reducing the vibration of the floating body and reducing the roughness of the waves of the jet solder. If the spring holder is a cap nut, when the cap nut comes into contact with the side plate, the action of the spring disappears and the floating body stops vibrating. At this time, the molten solder jetted from the nozzle is interfered with by the floating body, so the wave becomes rough, but this roughness is much smaller than the roughness caused by the vibration of the floating body.

In the case of the spring holder shown in Fig. 4, which uses washers, when the springs are brought into close contact, the spring action disappears and a gentle wave is produced.

When the strength of the compression spring reaches the vibration of the floating body suitable for soldering a printed circuit board, when the lock nut 9 is brought into close contact with the spring holder 8, the spring holder is fixed in that position and the floating body vibrates. You won't have to move even if you do. Furthermore, when the bolts 4 of the side plate 3 are heated, the side plate can be moved laterally within the horizontally long hole 5, and along with this movement, the floating body can also be moved left and right within the nozzle. It can be installed in any position.

Although the floating body in the embodiment of the present invention is shown as having a cylindrical shape, it goes without saying that the floating body is not limited to the cylindrical shape but can also be used in other shapes or with modifications thereof.

[Effect of idea]

As explained above, since the jet solder bath of the present invention uses a compression spring to hold the floating body, the vibration of the floating body can be adjusted steplessly from zero to maximum. Therefore, printed circuit boards that were conventionally soldered with more rough waves than necessary can now be soldered with appropriately rough waves, and the amount of oxide generated from molten solder due to rough waves is maximized. It is something that can be suppressed.

[Brief explanation of the drawing]

Figure 1 is an enlarged perspective view of the jet solder bath of the present invention.
FIG. 2 is a front sectional view of the same, FIG. 3 is an enlarged sectional view of a main part, and FIG. 4 is an enlarged sectional view of a main part of another embodiment. 1... Nozzle, 2... Nozzle plate, 3... Side plate,
7...Floating body, 8...Spring holder, 9...Lock nut, 10...Compression spring.

Claims (1)

[Claims for Utility Model Registration] (1) A hole is drilled in the side plate of the nozzle, a floating body is inserted into the hole, and a spring holder is attached to both ends of the floating body, and a space between the spring holder and the side plate is provided. A jet soldering bath characterized by the installation of a compression spring. (2) The jet solder bath according to claim 1, wherein the attachment position of at least one of the spring holders is adjustable.