JP2001036227A - Jet wave soldering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of a solder nonwetted portion on a substrate while the warping of the substrate is prevented. SOLUTION: A jet wave soldering device is provided with a warp preventing tool 20 which is brought into contact with the lower surface of a substrate 1 so as to prevent the substrate 1 from warping, in such a way that the central parts, etc., of the substrate 1 expands downward and is set up along the transporting direction A of the substrate 1 and sections 21 having nondividing shapes at the spots of the tool 20 corresponding to the jetting spots of primary and secondary jetting nozzles 11 and 12. The upper part 21a of each section 21 has an inverted V-shaped cross section, and the lower part 21b of the section 21 has a V-shaped cross section. The section 20 is formed in such a way that the upper end of the section 21 becomes lower than the contacting height L of melted solder J with the substrate 1. Therefore, the melted solder J can be prevented from being divided by the warping preventing tool 20 on the contacting surface of the solder j with the substrate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solder jet apparatus which enables a molten solder to be supplied to a substrate well.

[0002]

2. Description of the Related Art A molten solder spouted from a jet nozzle is supplied to a substrate on which a soldered component such as a surface-mounted component having no lead foot or a discrete component having a lead foot is mixed and conveyed in a predetermined direction. A soldering apparatus for performing soldering is already known.

As shown in FIG. 5, a soldering apparatus of this type includes a flux applying apparatus 2 for applying a flux to a substrate 1 and a soldered part, and a soldering part and a soldering part for satisfactorily drying the flux. A pre-heating device 3 including a panel heater or the like for pre-heating the substrate 1 and a molten solder supply unit 4 for supplying molten solder to the substrate 1 and soldering components are arranged in order along the substrate transport direction A. The substrate 1 is transported along a substrate transport path 6 by a pair of transport conveyors 5 that grip and transport both sides thereof.

[0006] As shown in FIGS. 6 and 7, for example, a molten solder supply section 4 supplies a primary jet nozzle 11 for supplying molten solder J satisfactorily to a substrate 1 on which electronic components are mounted over the entire solder surface. And a secondary jet nozzle 12 for removing excess molten solder J from the substrate 1 to which solder has been supplied. A primary nozzle duct 13 is connected to the primary jet nozzle 11, a secondary nozzle duct 14 is connected to the secondary jet nozzle 12, and these ducts 13 and 14 are solder dipping tanks in which molten solder J is stored. 15 is immersed. Then, by rotating the jet impellers 16, 17 arranged so as to face one end openings of the ducts 13, 14, the jet impellers 18, 19 provided in the primary jet nozzle 11 and the secondary jet nozzle 12, respectively. The molten solder J is ejected toward the substrate transfer path 6.

When soldering to a substrate 1 having a large uneven portion on which not only discrete components but also surface mounted components are mixed, gas generated when the molten solder J comes into contact with the substrate 1, The board transfer path 6 (board 1) is mounted so that air or the like near the mounted components does not collect on the lower surface of the board 1.
As shown in FIGS. 5 and 7, the transfer direction A) of the first jet nozzle 11 and the formation position of the jet port of the primary jet nozzle 11 are inclined upward in the downstream direction. On the other hand, when soldering is performed on the substrate 1 having only small discrete components and no surface mount components and having small uneven portions, a hole for inserting the discrete component into the substrate 1 is required. Is formed, the gas at the time of contact with the molten solder J,
Since the air near the components does not accumulate much on the lower surface of the substrate 1, as shown in FIG. 8 and FIG. It is constituted in the shape which becomes.

[0006] When the molten solder J is supplied to the substrate 1 conveyed to the molten solder supply unit 4, the substrate 1 is heated by the heat.
May expand and warp. In particular, when the central portion in the substrate width direction (the direction orthogonal to the substrate transport direction A) warps so as to swell downward, the molten solder J is formed along the swelling portion. It will approach and cause solder bridges. Therefore, in order to prevent such a problem, as shown in FIGS. 10 and 11, a warp stopper 20 is provided along the transfer position at the center of the substrate 1 so that the center of the substrate 1 expands downward. It has been proposed to prevent the warp so that the warp will come out. For example, as shown in FIG. 12A, the warp stopper 20 has a rectangular cross section.

[0007]

However, when such a warp stopper 20 is provided, FIGS. 12 (a) and 12 (b) will be described.
As shown in (1), the molten solder J is divided at the location where the warp stopper 20 is provided, and a non-wetting portion of the solder may be generated on the substrate 1. Also, since the heat dissipation phenomenon is increased by the warp stopper 20, the molten solder J escapes from the warp stopper 20, and the molten solder J tends to be further separated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object to provide a solder jet apparatus which does not cause a solder non-wetting portion on a substrate while preventing the substrate from warping. .

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method of supplying a molten solder to a substrate conveyed in a predetermined direction by blowing the molten solder upward from below. A solder jet device for performing attachment, wherein a warp prevention device is provided along the substrate transport direction to prevent the substrate from warping by contacting the lower surface of the substrate to which the molten solder is supplied. At least a part of the cross-sectional shape of the molten solder supply point is formed in a shape in which the molten solder is not divided by the warp prevention tool at the board contact point of the molten solder, and according to this configuration, the board is prevented from warping. In addition, it is possible to prevent the solder from being wetted on the substrate.

[0010]

According to the first aspect of the present invention, there is provided a solder jet flow in which a molten solder is jetted upward from below to a substrate conveyed in a predetermined direction to perform soldering while supplying the molten solder. In the apparatus, a warp prevention device is provided along the substrate transport direction to prevent the substrate from warping by contacting the lower surface of the substrate to which the molten solder is supplied, and the molten solder supply point in the warp prevention device is provided. At least a part of the cross-sectional shape is formed in such a shape that the molten solder is not divided by the warpage preventing tool at the position where the molten solder contacts the substrate.

With this configuration, the shape of the molten solder supply portion of the warp preventing device is formed so that the molten solder is not divided, so that it is possible to prevent the solder from being wetted on the substrate. . According to a second aspect of the present invention, in the solder jet device according to the first aspect, the non-divided shape portion of the warp prevention device, in which the molten solder is not divided, has an upper end portion lower than a contact height with the substrate. It has been formed.

[0012] With this configuration, since the upper end of the warp preventing device is lower than the contact height with the substrate, the molten solder covers the non-divided shape portion from above, and the molten solder is divided at the contact portion of the substrate. Can be prevented. In addition, since the cross-sectional area of the warpage preventer is reduced, the heat radiation phenomenon can be reduced, and the tendency of the molten solder to be divided can be reduced.

According to a third aspect of the present invention, in the solder jetting device according to the first or second aspect, the non-divided portion of the warp preventing device, in which the molten solder is not divided, has an inverted V-shaped cross section at the top. It is formed in a shape. With this configuration, the molten solder divided at the center or the like of the warpage prevention tool is connected well at the upper portion, and as a result, it is possible to prevent the molten solder from being divided at the substrate contact location.

According to a fourth aspect of the present invention, in the solder jet device according to any one of the first to third aspects, the non-divided shape portion of the warp preventing device, in which the molten solder is not divided, has a lower sectional shape. It is formed in a V-shape. With this configuration, when the molten solder ejected from below hits the V-shaped portion at the lower part of the non-divided shape portion, the flow of the molten solder is rectified, thereby making it difficult to prevent the upward flow. As a result, the size of the molten solder flowing along the warpage preventing device and the division can be minimized.

A solder jet apparatus according to an embodiment of the present invention will be described below with reference to FIGS. The components having the same functions as those of the conventional components are denoted by the same reference numerals, and description thereof will be omitted. As shown in FIGS. 1 and 2, even in this solder jet apparatus, the center portion of the substrate 1 warps so as to abut against the lower surface of the substrate 1 to which the molten solder J is supplied. Anti-warpage tool 20
Are provided along the substrate transport direction A.

However, unlike the conventional one, the warp preventing device 20 does not separate the molten solder J into a portion corresponding to the jetting position of the primary jet nozzle 11 or the secondary jet nozzle 12. An undivided shape portion 21 formed in a shape is provided. The non-divided shape portion 21 has an upper portion 21a having an inverted V-shaped cross-section, a lower portion 21b having a V-shaped cross-section, and has an ejection point of the primary jet nozzle 11 and a secondary jet nozzle 12 And the non-split portion 21
The upper end is formed to be lower than the contact height L of the molten solder J with the substrate 1.

Further, in the warp preventing device 20, a cut portion which is not covered with the molten solder J (in this embodiment, the substrate is located at a position closer to the substrate than the primary jet nozzle 11 and the secondary jet nozzle 12 in the warp preventing device 20). At a position slightly upstream with respect to the transport direction A), a cut portion 22 is provided in which the upper portion is cut out in a large V-shape when viewed from the side, and the contact height of the molten solder J with the substrate 1 is provided. (The non-divided shape portion 21
(Which is lower than the recessed portion). Further, the cross-sectional shape of the upper part of the warpage prevention tool 20 at the location of the cut portion 22 is formed in an inverted V-shape.

According to this configuration, as shown in FIG. 3, since the sectional shape of the lower portion 21b of the non-divided shape portion 21 is formed in a V-shape, the molten solder J jetted from below can be formed in the non-divided shape. When the flow n hits the lower part of the part 21, the flow n is rectified and flows along the V-shaped part at the lower part of the warpage preventing device 20. In addition, the non-divided shape portion 21
Is formed in an inverted V-shape, the flow m of the molten solder J divided at the center portion of the warpage preventing device 20 is good in the inverted V-shaped portion in the upper portion 21a. It comes along.

Further, at the point where the molten solder J is supplied to the substrate 1, the upper end of the warpage preventing tool 20 is formed to be lower than the contact height L with the substrate 1, so that the molten solder J As shown in FIG. 4, the non-divided shape portion 21 is covered from above, and the molten solder J
Can be prevented from being divided. Then, as described above, the sectional shape of the lower portion 21b of the non-divided shape portion 21 is formed in a V-shape,
By forming the cross-sectional shape of 1a into an inverted V-shape or by forming the upper end of the warpage prevention device 20 lower, the cross-sectional area of the warpage prevention device 21 becomes smaller than that conventionally proposed, so that the heat radiation phenomenon occurs. Can also be reduced.
However, it is possible to further reduce the tendency of the components to be separated at the location of the warpage preventing device 20.

As a result, the phenomenon of non-wetting of the substrate 1 due to the division of the molten solder J can be reliably prevented, and the reliability of the soldering process is improved. In addition,
The location where the upper end of the non-divided shape portion 21 is formed to be lower than the contact height L of the molten solder J with the substrate 1 is only above the primary jet nozzle 11 and the secondary jet nozzle 12. , Sufficiently smaller than the length of the substrate 1 in the longitudinal direction,
Therefore, the substrate 1 is prevented from warping while being favorably supported by the warpage preventing device 20 except for the jet position.

Further, at a cut portion where the molten solder J does not come into contact with the warp preventing device 20, a cut portion 22 is provided, the upper portion of which is cut into a large V-shape when viewed from the side. Since the cross-sectional shape of the upper part of the warpage prevention tool 20 at the location of the cut portion 22 is an inverted V-shape, it is minimal that the solder residue (oxidized solder) X floating on the liquid surface of the molten solder J accumulates in the cut portion 22. Can be kept to a minimum. Moreover, since the cut portion 22 is formed so that the upper end portion of this portion of the warpage prevention tool 20 is lower than the contact height of the molten solder J with the substrate 1,
Even if the solder dust X floating on the liquid surface of the molten solder J accumulates in the cut portion 22, the solder dust X does not come into contact with the substrate 1.
Is reliably prevented from adhering to the substrate 1, which also improves the reliability of the soldering process.

In the above embodiment, as the non-divided portion 21, the cross section of the upper portion 21a is formed in an inverted V-shape, the cross section of the lower portion 21b is formed in a V-shape, and the upper end is further formed. Is formed so as to be lower than the contact height L of the molten solder J with the substrate 1, and a case where the three components are combined as described above. It is possible to reliably prevent the molten solder J from separating on the contact surface of the substrate 1 on which the substrate 21 is provided. However, the present invention is not limited to this, and at least one of the above three components is required. By adopting, it is possible to reduce the separation of the molten solder J, and at least one of these components may be provided in the entire area of the solder supply. It is a matter of course have an effect be provided only in a part of.

Further, in the above-described embodiment, the case where the substrate transport path 6 (substrate transport direction A) and the location where the ejection port of the primary jet nozzle 11 is formed is inclined so as to be more upward on the downstream side. Although the adaptation is shown, it is not limited to this, and the substrate transport path 6 and the primary jet nozzle 1
It goes without saying that a similar configuration can be adopted for a configuration in which the formation location of one jet port is substantially horizontal.

[0024]

As described above, according to the present invention, a warp preventing device is provided along the board conveying direction to prevent the board from warping by contacting the lower surface of the board to which the molten solder is supplied. By forming the cross-sectional shape of at least a part of the molten solder supply point in the warp prevention tool into a shape in which the molten solder is not split by the warp prevention tool at the board contact point of the molten solder, the molten solder J is divided. The resulting non-wetting phenomenon on the substrate can be reliably prevented, and the reliability of the soldering process is improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a solder jet device according to an embodiment of the present invention.

FIG. 2A is an enlarged sectional view of a main part of the solder jet device,
FIG. 2B is a cross-sectional view taken along line BB of FIG.
FIG. 2C is a sectional view taken along line CC of FIG. 2A.

FIG. 3 is a conceptual cross-sectional view for explaining the operation of the solder jet device.

FIG. 4 is a schematic plan view of the solder jet device when looking down at a portion where a non-divided shape portion is provided from a substrate contact surface.

FIG. 5 is an overall sectional view of a conventional soldering apparatus.

FIG. 6 is a perspective view of a solder supply unit of the conventional soldering apparatus.

FIG. 7 is a sectional view of a solder supply unit of the conventional soldering apparatus.

FIG. 8 is an overall sectional view of another conventional soldering apparatus.

FIG. 9 is a sectional view of a solder supply section of the conventional soldering apparatus.

FIG. 10 is a perspective view of a solder supply unit of a conventionally proposed soldering apparatus.

FIG. 11 is a sectional view of a principal part of a solder jet part of the conventional soldering apparatus.

12A and 12B are a cross-sectional view and a plan view showing a state of contact with molten solder by a conventional warp preventing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 4 Molten solder supply part 5 Conveyor 6 Substrate conveyance path 11 Primary jet nozzle 12 Secondary jet nozzle 15 Solder dip tank 20 Warp prevention tool 21 Non-split shape part 22 Cut part A Substrate conveyance direction J Molten solder

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) // B23K 101: 42 (72) Inventor Takeshi Onobayashi 1006 Odakadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72 ) Inventor Tadahiko Sugimoto 1006 Kadoma Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. F-term (reference) 4E080 AA01 AB03 BA05 5E319 CC24 CD45 CD46

Claims (4)

[Claims] 1. A solder jet apparatus for performing soldering while supplying molten solder by ejecting molten solder from below to a substrate conveyed in a predetermined direction, wherein the molten solder is supplied. An anti-warp device is provided along the substrate transport direction to prevent the substrate from warping by contacting the lower surface of the substrate being soldered. A solder jet device formed in such a shape that the molten solder is not divided by the warpage preventing tool at the substrate contact portion. 2. The solder jet device according to claim 1, wherein the non-divided shape portion of the warp preventing device, in which the molten solder is not divided, is formed such that an upper end portion thereof is lower than a contact height with the substrate. . 3. The solder jet device according to claim 1, wherein the non-divided shape portion of the warp preventing device, in which the molten solder is not split, has an upper V-shaped cross section. 4. A non-divided shape portion of the warp preventing device in which molten solder is not divided has a lower sectional shape of V.
The solder jet device according to claim 1, wherein the solder jet device is formed in a letter shape.