JPH06209161A - Dip soldering device - Google Patents

Abstract

(57) [Abstract] [Purpose] Prevents unsoldered chip components on the flow soldering surface of the circuit board, prevents solder overcoating on the surface of the circuit board, and suppresses warpage of the circuit board during solder dipping. To do so. [Configuration] Solder tank 1 including first solder jet section 31 and second solder jet section 32 of first soldering station 11
In FIG. 8, the closing portion 34 where the punching hole 36 is not provided is provided in the substantially central portion of the first solder jet portion 31 in the width direction of the punching plate 35.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solder dipping device, and in particular, two solder jet parts are arranged along the carrying direction of a circuit board and the lower surface of the circuit board is soldered from the two solder jet parts. The present invention relates to a solder dipping device that is brought into contact with a jet stream to perform soldering.

[0002]

2. Description of the Related Art Circuit boards made of an insulating material have been conventionally used for assembling various electronic circuits. Copper foil is bonded onto such a circuit board, and the copper foil is etched to form a predetermined wiring pattern. Then, the leads of the circuit component are made to pass through the lead insertion holes, and in this state, they are supplied to the solder dip bath, and the pattern surface of the circuit board where the leads project is brought into contact with the solder jet flow, whereby the leads on the circuit board It is designed to be soldered to the connection land provided at the end of the wiring pattern.

[0003]

In the process of manufacturing such an electronic circuit, stress is generated at the soldering portion due to the lead cut of the circuit component. A double jet type automatic soldering device is used to prevent such stress and to prevent unsoldered solder. Two solder jet parts are arranged along the transfer direction of the circuit board. The lower surface of the circuit board is sequentially brought into contact with the solder jets from the two solder jet portions to perform solder dipping.

Generally, unsoldered solder cannot be completely detected only by visual inspection and electrical check, and such unsoldered solder may be found after passing through a distribution process to a user, which includes an unstable element. Therefore, in the first soldering, soldering is performed by the chip jet method to prevent unsoldering. Then, after this, in the second soldering, the stress of the soldered portion is improved by lead cutting and the bridge is corrected.

Due to the multifunctionalization, downsizing and cost reduction of electronic equipment, the mounting density of components on a circuit board is increasing. Due to the preheat and heat of the solder bath during flow soldering, the printed circuit board that constitutes the circuit board is heated and warps. A difference of about 2 mm is produced in the direction. That is, unsoldered solder is likely to occur at both ends in the width direction of the printed circuit board. On the other hand, in the center portion in the width direction, the solder flows into the surface of the printed circuit board from the opening provided in the vicinity of the center part and the solder cover It is easy to occur.

As a countermeasure for the warp of the printed circuit board, a bar may be inserted in the central part of the solder bath or a warp prevention bar may be provided. However, since the mounting density of components is high, a no land or no component band is provided in the central part of the printed circuit board. Since it cannot be provided, a masking tape is attached to the opening to prevent soldering.

The present invention has been made in view of the above problems, and suppresses unsolder on both sides in the width direction of a circuit board transported on a solder dip tank, and at the same time, the central portion of the printed board. It is an object of the present invention to provide a solder dipping device capable of effectively preventing the occurrence of a solder cover on the surface of a printed circuit board through the opening.

[0008]

According to a first aspect of the present invention, two solder jet parts are arranged along the carrying direction of a circuit board, and the lower surface of the circuit board is formed into a solder jet from the two solder jet parts. In a solder dipping device in which soldering is performed by sequentially contacting each other, a solder jet at a substantially central portion in a direction orthogonal to a transport direction of a first solder jet portion upstream in a transport direction of a circuit board is blocked. Relates to a solder dipping device.

A second invention is the same as the first invention,
The present invention relates to a solder dipping device, characterized in that the solder jet portion is closed by a width of 50 to 100 mm.

[0010]

According to the first aspect of the invention, the circuit board sequentially comes into contact with the jetted solder in each of the two solder jet parts arranged along the carrying direction, and soldering is thereby performed. In the first solder jet portion, since the solder jet is blocked at the substantially central portion in the direction orthogonal to the transport direction, the solder does not contact the lower surface of the circuit board at this portion, Only will come into contact with the solder jet.

According to the second aspect of the invention, the circuit board is soldered by contacting with the solder jet except for a portion having a width of 50 to 100 mm at a substantially central portion in the width direction.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the overall construction of a solder dipping device according to an embodiment of the present invention. This solder dipping device comprises a first soldering station 11, a cutting station 12 and a second soldering station. Attachment station 13
It consists of and. A conveyor 14 is provided so as to pass through these three stations in the vertical direction.
The circuit board 15 is sequentially transported on the 1, 12, and 13.

The first soldering station 11 includes a fluxer 16, a preheater 17, and a solder bath 18. The fluxer 16 is adapted to apply flux to the lower surface of the circuit board 15 conveyed by the conveyer 14, and then preheated by the preheater 17. Then, after this, soldering is performed in the solder bath 18. As will be described later, the solder bath 18 includes a first solder jet part 31 and a second solder jet part 32.

The cutting station 12 is the cutter 2.
1, which is a lead projecting to the lower surface of the circuit board 15 conveyed by the conveyor 14 by rotationally driving the cutter 21 by the motor 22, and the tip of the lead soldered at the soldering station 11. Is designed to disconnect.

The second soldering station 13 includes a fluxer 25, a preheater 26, and a solder bath 27.
Then, flux is applied to the lower surface of the circuit board 15 conveyed by the conveyer 14 in the fluxer 25, preheating is performed by the preheater 26, and soldering is performed on the lower surface of the circuit board 15 by the solder bath 27. The solder bath 27 is designed to generate a weak solder jet, and is designed to improve reliability by preventing unsoldered solder.

FIG. 2 shows the solder bath 18 of the first soldering station 11, which solder bath 18 has the first jet part 3
1 and the second jet part 32. Conveyor 1
First, the circuit board 15 transported by 4 is first solder jet part 31.
It contacts the upper solder, and then contacts the solder of the second solder jet portion 32. The pair of jet parts 31 and 32 both include a motor 33.

A pair of solder jet parts 31 of the solder bath 18,
A blocking portion 34 is provided in substantially the central portion of the solder jet portion 31 on the upstream side of the circuit board 15 in the transport direction of the 32. In this portion, a punching hole 36 is formed in a punching plate 35 of the solder jet portion 31. I try not to. That is, in the first solder jet portion 31, the circuit board 15 transported on the first solder jet portion 31 comes into contact with the jet stream of the solder ejected from the punching holes 36 only on both sides in the width direction, but in the middle portion in the width direction, the solder substrate It does not come into contact with the jet.

FIG. 3 shows the circuit board 1 on the first solder jet 31.
5 shows the state of being conveyed, and at this time, the lead 41 of the circuit component 40 on the circuit board 15 is in contact with the solder jet as shown in FIG. 5 to be soldered. The chip component 42 is soldered and attached to the lower surface of the circuit board 15 before being supplied to the first soldering station 11 including the solder bath 18. In addition, here, as described above, due to the closing portion 34 of the punching plate 35, the central portion in the width direction of the circuit board 15 does not come into contact with the solder jet, so that soldering is not performed. .

On the other hand, as shown in FIG. 4, in the second solder jet portion 32, the punching plate 35 is not provided with the closing portion 34, and the punching hole 36 is provided over the entire width of the circuit board 15. The solder jets ejected from the contact parts come into contact with each other, and as shown in FIG.
All the leads 41 are soldered.

That is, in the solder dipping device according to this embodiment, the solder bath 1 of the first soldering station 11 is used.
The first solder jet portion 31 of No. 8 is 50 to 100 mm at the substantially central portion in the width direction according to the warp of the circuit board 15.
About the size, the hole 36 at the center of the solder jet nozzle
Is closed, and soldering is performed only on both ends of the circuit board 15. Further, the soldering to the central portion of the circuit board 15 is performed by the other solder jet nozzle 32, and the rotation speed of the motor 33 is adjusted so that the surface of the circuit board 15 is not covered with solder from the opening. I solder it.

Thus, the solder bath 1 including the pair of solder jet parts 31, 32 of the first automatic soldering station 11
In FIG. 8, in accordance with the warp of the circuit board 15, the jet hole 36 at the central portion in the width direction of one solder jet part 31 is closed, soldering is performed on the surface of the circuit board 15 with less warp, and the other solder is soldered. The circuit board 15 is soldered by the jet portion 32.

Therefore, the chip component 42 on the flow soldering surface
In addition to suppressing unsoldered solder, soldering on the surface of the circuit board 15 in the first solder jet portion 31 of the first soldering station 11 is prevented. Therefore, by such a measure, it is not necessary to attach a masking tape to the opening provided at the substantially central portion of the circuit board 15 to prevent the soldering. Also the first
Providing the blocking portion 34 in the central portion in the width direction of the jet flow portion 31 has a great effect in preventing the warp of the circuit board 15 due to the thermal stress in the solder bath 18 of the circuit board 15.

[0023]

According to the first aspect of the present invention, the solder jet at the substantially central portion in the direction orthogonal to the carrying direction of the first solder jet part on the upstream side in the carrying direction of the circuit board is blocked. Therefore, according to such a configuration, unsoldering of the chip component on the flow soldering surface can be suppressed, and at the same time, the soldering on the surface of the circuit board can be prevented. Further, it becomes possible to reduce the warp of the circuit board due to heat.

According to the second aspect of the invention, the solder jet portion is closed by a width of 50 to 100 mm in the width direction of the circuit board. Therefore, according to such a configuration, the solder jet does not come into contact with the solder jet for about 50 to 100 mm at a substantially central portion in the width direction of the circuit board, which is great in preventing warpage due to thermal stress in a circuit board of a normal size. It will be effective.

[Brief description of drawings]

FIG. 1 is a front view showing the overall configuration of a solder dipping device.

FIG. 2 is a plan view of a solder bath of the first soldering station.

FIG. 3 is a sectional view of a first solder jet portion.

FIG. 4 is a sectional view of a second solder jet portion.

FIG. 5 is an enlarged sectional view of an essential part showing soldering in a first solder jet part.

FIG. 6 is an enlarged sectional view of an essential part showing soldering in a second solder jet part.

[Explanation of symbols]

 11 First Soldering Station 12 Cutting Station 13 Second Soldering Station 14 Conveyor 15 Circuit Board 16 Fluxer 17 Preheater 18 Solder Vessel 21 Cutter 22 Motor 25 Fluxer 26 Preheater 27 Solder Vessel 31 First Solder Jet Section 32 Second Solder Jet Section 33 Motor 34 Closing Part 35 Punching Plate 36 Punching Hole 40 Circuit Parts 41 Lead 42 Chip Parts

Claims (2)

[Claims] 1. Two solder jet parts are arranged along the carrying direction of the circuit board, and the lower surface of the circuit board is brought into contact with the solder jets from the two solder jet parts in order to perform soldering. In the solder dipping device, the solder dipping device is configured so as to close a solder jet at a substantially central portion in a direction orthogonal to a transport direction of a first solder jet portion on an upstream side in a transport direction of a circuit board. 2. The solder dipping device according to claim 1, wherein the solder jet portion is closed by a width of 50 to 100 mm.