JPH0227833B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides parts such as square chip parts and Melf-shaped chip parts at predetermined locations on a printed wiring board.
Concerning methods for soldering.

[Conventional technology]

Conventionally, in this type of soldering, cream solder is applied to a predetermined position on a printed wiring board in advance, and an adhesive is also applied, and the parts to be soldered are adhered onto the adhesive. By heating this, the adhesive state of the parts concerned is solidified, and in this way, an immovable state is ensured.The above-mentioned cream solder is melted by heating the parts at high temperature with a soldering iron, etc. It is air-cooled to solidify.

For this reason, when using the conventional method as described above, it is necessary not only to apply cream solder but also to apply an adhesive, and a heating operation is also required to harden the adhesive, which requires considerable labor for soldering. Not only is this inefficient as it requires a lot of time, but the heating and cooling of the adhesive causes it to expand and contract until it hardens, causing the parts to shift from their designated positions. Therefore, there is a problem in that such positional deviations must be detected and adjustments must be made to correct the position.

Therefore, in order to solve the above problem, a suction head is used to suction and hold a desired electronic component, and the electronic component is placed across the solder pads on a printed circuit board, and in this state, it is lowered from both sides of the suction head. A method for mounting electronic components has also been proposed (Japanese Patent Publication No. 57-42999) in which a bonding chip is brought into contact with a solder pad, and when the solder melts, the bonding chip is pulled up and the solder solidifies.

However, in the above method, the electronic components transferred by the suction head are not preheated at all, so it takes a considerable amount of time for the bonding chip to melt the solder, which makes it difficult to improve efficiency. It has become unsatisfactory.

On the other hand, it has been proposed (Utility Model Publication No. 57-65771) to preheat the electronic components mentioned above before soldering. , on its tip surface,
A receiving groove is provided in which the chip part is accommodated by suction, and the chip part is transferred to the printed circuit board in this state, so that the chip part is preheated during this time.

However, when using the above conventional example, the terminal surface to be soldered of the chip component stored in the receiving groove does not come into contact with the soldering iron tip, so the preheating of the important part is not sufficient and the soldering iron tip does not come into contact with the soldering iron tip. As the upper surface of the chip component that comes into contact with the tip receives heat conduction, the temperature at the center of the chip component rises rapidly.As a result, especially in the case of ceramic capacitors, the component can be damaged due to overheating such as cracking. It will cause it.

[Problem that the invention seeks to solve]

The present invention has been studied in view of the above-mentioned defects of the conventional example, and it not only holds the required electronic component only by suction means, but also separately holds both the left and right parts of the component using gripping arms. This prevents the occurrence of accidents such as falling parts during transport, and also preheats the parts from both the left and right sides using the clamping arms, which prevents heating from the top of the parts. As shown in Figure 2, not only is it possible to prevent overheating of the component and to improve the efficiency of the soldering work by preheating, but also to send out gas from the lower end nozzle that was performing the above-mentioned adsorption after melting the solder. The purpose of this is to rapidly cool and solidify the molten solder, improve the efficiency of the soldering process, and prevent heat damage to ceramic capacitors by preventing the parts in question from heating up. be.

[Means for solving problems]

The soldering method according to the present invention is characterized by preheating the left and right sides of the component by holding it between a pair of heated holding arms, and attaching the lower end of the air intake/air supply push-down tube to the upper surface of the component. Press the nozzle part,
By suctioning the component with air, the preheated component is placed at a predetermined position on the printed wiring board and pressed across multiple solder spots that have been previously attached, and the gripping arm When the solder is melted by heat transfer through the tip of the component, the clamping arm is separated from the component, and the gas or component is sent out from the lower end nozzle of the intake/air supply push-down pipe, respectively. The purpose is to rapidly cool and solidify the molten solder by means of gas jetted outward through an air supply passage formed with the lower end nozzle portion in contact with the upper surface.

〔Example〕

To explain the present invention in detail with reference to the drawings, it is preferable to use a clamping type soldering iron 1 as shown in FIG. 2 as a tool for carrying out the invention.

The soldering iron 1 has a clamping body 2 that can be opened and closed manually or automatically by a desired power, and a long first body 2'.
and a short second body 2'' are pivotally connected by a shaft pin 3, and both bodies 2', 2''
is made to be movable to the left and right as shown by the arrow by an appropriate means (not shown), and thereby the clamping arms 4, 4' fixed inside the tips of the main bodies 2, 2' can be opened and closed freely. The parts A can be held between the arms 4 and 4' and separated from each other.

The holding arms 4, 4' shown in the figure are formed by a square plate-shaped ceramic heater 5, and in the figure, 6, 6' indicate a pair of lead wires connected to the power supply. The screw rod 7 protruding from the outer surface is connected to the through hole 8 of the first and second bodies 2, 2'.
The ceramic heater 5 is fixed to both the main bodies 2, 2' by screwing the screw 9 through it.
The ceramic heater 5 is heated by energizing the lead wires 6, 6'.

Next, in FIG. 2, reference numeral 7 denotes a suction/air supply push-down pipe attached to the soldering iron 1 so as to be able to move up and down by a manual or automatic transmission mechanism (not shown); The lower end nozzle 7' of the part 7 can be pressed against the upper surface of the clamped part A as described later.

That is, the push-down tube 7 is penetrated with a vent hole 8, and this communicates with an air suction section 9 provided by a vacuum pump, a blower, etc., so that when the vacuum pump is operated, air is removed from the opening 8' of the vent hole 8. Air can be taken in, and air can be blown out from the same port 8' by operating as a blower.

Further, on the lower end surface of the lower end nozzle portion 7',
Air supply passages 10, 10 are arranged radially as shown in the figure.
. . . is bored in the form of a narrow groove in communication with the opening 8'.

To carry out the method of the present invention using the soldering iron 1 having the above-mentioned configuration, the soldering iron 1 is first operated manually or automatically as shown in a in FIG. The desired part A that is
While holding the part A by the pair of holding arms 4 and 4', the intake/air push-down pipe 7 is lowered to bring the lower end nozzle part 7' into contact with the upper surface of the part A, and the intake air part 9 is in the suction operation state, and the part A is sucked.

At this time, there are the intake air passages 10, 10, . . . as described above, but since the air passages are formed to be narrow, they do not interfere with the above-mentioned suction.

In this way, the part A is held between the holding arms 4 and 4' and is also adsorbed to the lower end surface of the lower end nozzle part 7', so that it will not fall during transportation, and in this case, the If the push-down tube 7 is made of a material with good thermal conductivity, the component A can be preheated to an appropriate temperature without being overheated.

On the other hand, on the printed wiring board B to which this part A is to be soldered, solders D and D', such as cream solder, are applied in advance to the required wiring metals C and C', and the solders D and D', such as cream solder, are applied in advance to the required wiring metals C and C'. The component A is placed on the device across the solders D and D' as shown in FIG.

As a result, the lower portions of the holding arms 4, 4' come into contact with the solders D, D', and since the part A is preheated at this time, the solders D, D' are quickly melted. However, at this time, the intake/air supply push-down pipe 7 is
Even if the abutment state is maintained and the intake state stops, the intake may continue as it is.

When the solders D and D' have completely melted, the clamping arms 4 that had been clamping the parts until then,
The soldering iron 1 is operated so that the soldering iron 4' moves away from the component A, resulting in the state shown in d in FIG. By operating as a blower,
Air is blown outward through the air passages 10, 10, which are tubular on the upper surface of the ventilation hole 8-opening 8'-component A, and thereby the melted solder is rapidly air-cooled. solidified.

In the above embodiment, the lower end nozzle portion 7' has an air supply vent.
10, 10, etc., but if such a device is not provided, move the intake/air supply push-down pipe 7 a little upwards in step d of FIG. It is also possible to perform air cooling by releasing the contact with the opening 8' and allowing air to flow out from the opening 8'.
Once the solder has solidified in this way, the push-down tube 7
This causes the air to move upward, which of course also stops the air from flowing out.

Of course, the operation of the soldering iron 1 as described above can be fully automated in accordance with the clamping of chip parts and the soldering position and orientation of the part A stored in advance by a computer.

〔Effect of the invention〕

The present invention can be carried out as described above, and in addition to suctioning the upper surface of the required part by the lower end nozzle part of the intake/air supply push-down pipe, both the left and right sides of the part are held by the gripping arms. Because they are clamped, even if a failure occurs on either side, the parts will not fall inadvertently during transport.Furthermore, the clamping arms primarily preheat both the left and right sides of the parts, rather than the top surface. Therefore, only the parts that require the most preheating are heated, and the next process of soldering can be performed quickly.Moreover, since both the left and right parts are heated, thermal damage due to heating inside the part is less likely to occur.
Thermal damage to components due to overheating is also less likely to occur.

Furthermore, since the upper surface of the component is attracted by the lower end nozzle section, heat is removed from the upper surface of the component through the lower end nozzle section, and from this point of view as well, it is possible to eliminate the risk of overheating. can.

Moreover, in the present invention, the lower end nozzle part is not only used for suction, but also gas is sent out from the nozzle part in the final process and is delivered to the upper surface of the component. Furthermore, not only is heating of the component suppressed, but also the solder can be rapidly cooled and solidified, thereby improving the efficiency of this type of work.

In addition, when sending the above-mentioned cooling gas without separating the lower end nozzle part from the top surface of the component, the intake air cools the component even during the process of transferring the component from the air supply air passage. , it is possible to completely prevent thermal destruction of components due to preheating by the clamping arms.

[Brief explanation of drawings]

Figures a to e in Figure 1 are process explanatory diagrams of the soldering method according to the present invention, and Figure 2 is a partially cutaway diagram showing a clamping type soldering iron that can be used to implement the method. Fig. 3 shows the intake and air supply push-down pipe of the same iron;
b is a bottom end view of the same. 4, 4'...Pinching arm, 7...Intake/air supply push-down pipe,
7'...Lower end nozzle part, 10...Air supply passageway, A
...Parts, B...Printed wiring board, D, D'...
…solder.

Claims (1)

[Scope of Claims] 1. Both the left and right sides of the part are held between a pair of heated holding arms to preheat the part, and the lower end nozzle part of the intake/air supply push-down pipe is pressed against the upper surface of the part. ,
By suctioning the component with air, the preheated component is placed at a predetermined position on the printed wiring board and pressed across multiple solder spots that have been previously attached, and the gripping arm When the solder is melted by heat transfer through the tip of the component, the clamping arm is separated from the component, and the gas or component is sent out from the lower end nozzle of the intake/air supply push-down pipe, respectively. A printed wiring board characterized in that melted solder is rapidly cooled and solidified by gas ejected outward through an air supply gap path formed when the lower end nozzle portion is in contact with the upper surface. How to solder parts. 2. Soldering components to a printed wiring board according to claim 1, in which the intake operation of the intake/air supply push-down pipe is stopped if the component is placed on the device across multiple soldering locations and pressed. How to attach.