JP2009164303A - Soldering device and soldering method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a soldering device and a soldering method, wherein unevenness in temperature is reduced, allowing soldering at an even temperature, even with a large article. <P>SOLUTION: The soldering device 10 includes an induction coil 11 in which a work 20 is inserted, where a substrate 26 on which a circuit component 28 is placed via a solder material 30 is placed on a heating plate 42, being a first magnetic body. The induction coil 11 is applied with an AC current to generate an AC magnetic field so that the heating plate 42 of the work 20, placed in the induction coil 11, is induction-heated; thus the solder material 30 is melted and the circuit component 28 is soldered to the substrate 26; and a second magnetic body 41, which is different from the heating plate 42, is arranged near the heating plate 42, in the induction coil 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a soldering apparatus and a soldering method using an induction heating phenomenon, and more particularly to a technique for soldering at a uniform temperature by reducing temperature unevenness even in a large product.

  A technique relating to an apparatus for melting a solder material arranged in the vicinity of a circuit component by using an induction heating phenomenon and soldering the circuit component to a substrate with the molten solder material is disclosed (for example, `` Patent Document '' 1 "," Patent Document 2 "). The induction heating phenomenon here refers to the generation of an alternating magnetic field by energizing an alternating current through an induction coil, the generation of an alternating current in a magnetic material or conductor existing in the alternating magnetic field, and the magnetic material or conductor is caused to flow by the alternating current. A phenomenon that generates heat. Hereinafter, it is simply referred to as induction heating.

In the soldering apparatus according to Patent Document 1, a technique is disclosed in which circuit components and a solder material are placed on an iron-based wiring board, and the iron-based wiring board is placed inside an induction coil. By applying an alternating current to the induction coil, a substantially uniform magnetic flux is generated in the periphery of the iron circuit board to heat the iron circuit board. The solder material is melted by the heated iron-based circuit board, and the circuit components are soldered to the board.
In the soldering apparatus according to Patent Document 2, a technique is disclosed in which a magnetic material is disposed between induction coils together with an object to be heated, and the magnetic flux density around the object to be heated is changed. With such a configuration, the eddy current induced in the object to be heated is reduced, and the temperature rise of the object to be heated is suppressed.
JP 2007-36110 A JP 2006-294396 A

  Hereinafter, a conventional configuration of a technique for melting a solder material using an induction heating phenomenon and soldering a circuit component to a substrate with the melted solder material will be described with reference to FIGS. 6 is a schematic sectional side view of a soldering apparatus according to the configuration of the prior art, FIG. 7 is a schematic sectional side view showing the state of generation of magnetic flux around the workpiece according to the prior art, and FIG. It is the schematic bottom view which showed the generation | occurrence | production state of the eddy current. In the description of induction heating in this specification, the description of the soldering apparatus is limited to two dimensions, but the same action and effect can be obtained even if it is expanded to three dimensions.

  As shown in FIG. 6, the soldering apparatus 10 has the circuit components 28 (28a, 28b, and 28c), the solder material 30 (30a, 30b, and 30c), and the circuit components 28 and the solder material 30 at predetermined positions. A positioning jig 24 for guiding, a circuit board (hereinafter referred to as a board) 26 on which the circuit component 28, the solder material 30, the positioning jig 24 and the like are placed, and a heating plate 42 which is a magnetic body on which the board 26 is placed, , A conveyor 14 for conveying the heating plate 42 (corresponding to a support portion of the heating plate 42), an induction coil 11 surrounding the middle of the conveyor 14, and a controller (not shown) for controlling these. The circuit component 28, the solder material 30, the positioning jig 24, the substrate 26 and the heating plate 42 are collectively referred to as a workpiece 20. In the workpiece 20, the circuit component 28 is placed on the substrate 26 via the solder material 30.

  The circuit components 28a, 28b, and 28c are arranged at various positions on the substrate 26 depending on the circuit configuration. Solder materials 30a, 30b, and 30c for soldering the circuit components 28a, 28b, and 28c to the substrate 26 also correspond to the arrangement of the circuit components 28a, 28b, and 28c, and the circuit components 28a, 28b, and 28c, and It arrange | positions in the various positions of the board | substrate 26 so that the board | substrate 26 may be contacted. That is, the solder materials 30a, 30b, and 30c are placed on the substrate 26, and the circuit components 28a, 28b, and 28c are placed on the solder materials 30a, 30b, and 30c.

Induction coil 11 is formed by winding 12. In each figure in the present invention, the winding wire 12 is drawn thick for convenience of explanation. Actually, the induction coil 11 is formed by winding many times with a thinner wire than each figure.
As shown in FIG. 6, the length of the induction coil 11 is formed longer than the length of the workpiece 20 in the transport direction. Further, the through space inside the induction coil 11 is formed with a size sufficient to place the work 20.
The workpiece 20 is arranged at a substantially central position in the vertical section of the internal space of the induction coil 11 by the conveyor 14. In other words, the conveyor 14 is arranged so that the workpiece 20 is arranged at substantially the center inside the induction coil 11. This place is a place where the magnetic flux density generated by the induction coil 11 is substantially uniform, and the AC magnetic field is configured to act uniformly on the workpiece 20.

  The conveyor 14 is disposed so as to penetrate the inside of the induction coil 11. When the workpiece 20 is conveyed into the through space of the induction coil 11 by the conveyor 14, an alternating current is applied to the induction coil 11 by a controller (not shown). An alternating magnetic field is generated in the induction coil 11 by an alternating current that is energized, and the induction heating action of the alternating magnetic field raises the temperature of the heating plate 42 in the workpiece 20, and the heat is transmitted to the solder material 30, and the solder material 30 is heated and melted. When the solder material 30 is heated and melted, the controller stops energization of the alternating current. When the temperature of the solder material 30 is lowered and solidified, the circuit component 28 and the substrate 26 on the workpiece 20 are fixed (soldered).

  Next, the induction heating action generated in the work 20 arranged inside the induction coil 11 will be described with reference to FIG. The workpiece 20 is placed on the conveyor 14 inside the induction coil 11. The induction coil 11 shown in FIG. 7 shows the direction of current at a certain moment when an alternating current is applied. In FIG. 7, it is assumed that the entire workpiece 20 is made of a magnetic material for the sake of simplicity.

  In the winding 12 of the induction coil 11 located in the upper part of FIG. 7, a current flows from the back side to the front side. In addition, a current flows through the winding 12 of the induction coil 11 located in the lower part of FIG. 7 from the front side to the back side. A magnetic flux 100a is generated in a counterclockwise direction so as to surround the entire winding 12 of the induction coil 11 located in the upper part of FIG. A magnetic flux 100b is generated in the clockwise direction so as to surround the entire winding 12 of the induction coil 11 located below in FIG. Inside the induction coil 11 (through space), the magnetic fluxes 100a and 100b are directed from left to right. Since the total length L of the induction coil 11 is sufficiently longer than the length W of the workpiece 20, magnetic fluxes 100a and 100b pass through the workpiece 20 in parallel (see FIG. 8).

When the magnetic flux density generated by the induction coil 11 is changed by the alternating magnetic field, an eddy current 102 is generated on the work 20 in a plane perpendicular to the direction of the magnetic flux 100 by electromagnetic induction. The direction is a direction in which magnetic flux is generated so as to cancel the increase and decrease in magnetic flux density. For example, when the amount of current flowing through the induction coil 11 decreases or when the direction of current flow is reversed and the magnetic fluxes 100a and 100b decrease, the direction shown in FIG. The eddy current 102 is generated clockwise (in the direction), and the magnetic fluxes 104a and 104b generated in the workpiece 20 at this time are in the same direction as the magnetic fluxes 100a and 100b generated by the induction coil 11.
On the other hand, when the amount of current flowing through the induction coil 11 increases and the magnetic fluxes 100a and 100b increase, the direction of the eddy current 102 generated in the workpiece 20 is reversed, and the direction of the magnetic fluxes 104a and 104b is This is the opposite direction to the magnetic fluxes 100a and 100b generated by the induction coil 11.

  Here, it is known that the eddy current 102 flows near the center of the surface of the heating plate 42 as shown in FIG. Since the amount of induction heating action of the alternating magnetic field on the heating plate 42 depends on the current density, heat generation is concentrated in a portion where the amount of current is large, the central portion 42a of the heating plate 42 is locally hot, and the processing target is large. In particular, there is a problem that the soaking property of the heating plate 42 is deteriorated.

According to Patent Document 1, a technique for changing the number of windings of the induction coil and the cross-sectional area of the induction coil is disclosed. However, it is time-consuming to change the shape of the induction coil for each product having a different size. Cost loss is large, and it is difficult to change the magnetic field suitable for each shape and material.
Further, according to Patent Document 2, a technique for changing the magnetic flux density at both ends of a heating target is disclosed, but it is difficult to suppress a local temperature rise such as a central portion of a workpiece.

  In order to solve the above-described problems, the present invention provides a soldering apparatus and a soldering method in which temperature unevenness in the entire workpiece is reduced, and products of different sizes can be soldered at a uniform temperature. It is to provide.

  The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

  That is, according to the first aspect of the invention, there is provided an induction coil through which a work configured by placing a substrate on which circuit components are placed via a solder material on a heating plate as a first magnetic body is inserted. Then, by means of an alternating magnetic field generated by applying an alternating current to the induction coil, a heating plate of a work placed in the induction coil is induction-heated to melt the solder material, and the circuit component is attached to the substrate. A soldering apparatus configured to solder to the heating coil, wherein a second magnetic body different from the heating plate is arranged in the vicinity of the heating plate in the induction coil.

  According to a second aspect of the present invention, the soldering apparatus includes a plurality of the second magnetic bodies, and a plurality of driving units that individually raise and lower the second magnetic bodies, The distance between the second magnetic body and the heating plate can be changed by the driving means.

  According to a third aspect of the present invention, the soldering apparatus determines whether or not the surface temperature detected by the temperature detection means is equal to or higher than a predetermined set value that is detected in advance. A calculating means, and when the surface temperature is determined to be equal to or higher than a set value by the calculating means, the distance between the second magnetic body and the heating plate is made closer by the driving means. It is a thing.

  5. The induction coil according to claim 4, wherein a work configured by placing a substrate on which a circuit component is placed via a solder material on a heating plate which is a first magnetic body is inserted into the induction coil, and the induction coil A soldering method configured to melt the solder material by induction heating the heating plate by an alternating magnetic field generated by applying an alternating current to the circuit board, and solder the circuit component to the substrate, The attaching method includes a temperature detecting step for detecting the surface temperature of the workpiece, a calculating step for calculating whether the surface temperature detected in the temperature detecting step is equal to or higher than a predetermined set value, and the induction coil. When a plurality of second magnetic bodies different from the heating plate are arranged in the vicinity of the heating plate and the surface temperature is determined to be equal to or higher than a set value by the calculation step, the second magnetic body When, in which and a driving step closer the heating plate, the distance.

  As effects of the present invention, the following effects can be obtained.

According to the present invention, it is possible to reduce the generation of eddy currents in the heating plate in the vicinity of the place where the second magnetic body is disposed, and it is possible to suppress the temperature rise of the workpiece in that portion.
Therefore, by arranging the second magnetic body in the vicinity of the high temperature portion in the heating plate where there is a portion where the temperature is higher than other portions, temperature unevenness in the heating plate is reduced, and processing is performed. Even when the object is large, it is possible to perform soldering at a uniform temperature. In addition, it is possible to change the magnetic field suitable for each shape and material for different products without changing the steps, thereby improving productivity. Furthermore, it can be applied to products for soldering with a wide temperature range, and solders having different melting points can be soldered with a single facility.

Next, embodiments of the invention will be described.
FIG. 1 is a schematic sectional side view of a soldering apparatus according to Embodiment 1 of the present invention.
FIG. 2 is a schematic side view showing the magnetic flux distribution around the heating plate according to the present invention.
FIG. 3 is a schematic bottom view showing an eddy current generation state in the heating plate according to the first embodiment of the present invention.
FIG. 4 is a schematic sectional side view of a soldering apparatus according to Embodiment 2 of the present invention.
FIG. 5 is a schematic sectional side view of a soldering apparatus according to Embodiment 3 of the present invention.
FIG. 6 is a schematic sectional side view of a soldering apparatus according to the configuration of the prior art.
FIG. 7 is a schematic sectional side view showing the state of magnetic flux generated around the workpiece according to the prior art.
FIG. 8 is a schematic bottom view showing the state of eddy current generation in the heating plate according to the prior art.
It should be noted that the technical scope of the present invention is not limited to the following examples, but broadly covers the entire scope of the technical idea that the present invention truly intends, as will be apparent from the matters described in the present specification and drawings. It extends.

  Below, the soldering apparatus which concerns on this invention is demonstrated.

[Example 1]
First, Example 1 of the soldering apparatus 10 according to the present invention will be described with reference to FIGS. FIG. 1 is a schematic sectional side view of a soldering apparatus 10 according to this embodiment.
A soldering apparatus 10 shown in FIG. 1 includes a configuration of a work 20 including a circuit component 28, a solder material 30, a positioning jig 24, a substrate 26, and a heating plate 42, and the work 20 is moved by an inner space of the induction coil 11 by a conveyor 14. The basic configuration is substantially the same as that of the soldering apparatus 10 according to the prior art shown in FIGS. Therefore, in the following description, detailed description is omitted about the part which overlaps with the soldering apparatus 10 which concerns on a prior art. In the present specification, the configuration using the heating plate 42 is described. However, when the substrate 26 or the solder material 30 is a magnetic body, a configuration in which the heating plate 42 is not used is also possible. .

  As shown in FIG. 1, in the soldering apparatus 10 according to the present embodiment, second magnetic bodies 41 and 41 different from the workpiece 20 are arranged in the induction coil 11. Specifically, the magnetic bodies 41 and 41 are arranged below the heating plate 42 in the induction coil 11 and in the vicinity of the central portion 42a of the heating plate 42, that is, in the vicinity of a portion that becomes high temperature in the conventional configuration. In this embodiment, two magnetic bodies are arranged, but one or three or more magnetic bodies may be used, and the number is not limited.

  FIG. 2 is a schematic side view showing the distribution of the magnetic flux 100 around the heating plate 42 according to the present invention. In FIG. 2, the magnetic body 41 is not shown as one piece. As shown in FIG. 2, the magnetic body 41 changes the generation of the magnetic flux 100. Specifically, by bringing the magnetic body 41 closer to the heating plate 42, a part of the magnetic flux 100 that has passed through the heating plate 42 leaves the heating plate 42 and passes through the magnetic body 41. As a result, the density of the magnetic flux 100 passing through the heating plate 42 decreases near the magnetic body 41.

  As a result, as shown in FIG. 3, the eddy current 102 flowing in the central portion is smaller than the eddy currents 102 and 102 flowing in both end portions. That is, the current amount and the heat generation amount in the central portion are not concentrated, and the induction heating action acts uniformly on the entire heating plate 42.

  By configuring as described above, the temperature unevenness on the heating plate 42 is reduced, and even when the object to be processed is large, soldering can be performed at a uniform temperature. In addition, the magnetic field suitable for each shape and material can be changed without change for different products, and productivity can be improved. Furthermore, it can be applied to products that perform soldering with a wide temperature range, and solder with different melting points can be soldered with a single facility.

[Example 2]
Next, a second embodiment of the soldering apparatus 10 according to the present invention will be described with reference to FIG. In addition, about the soldering apparatus 10 demonstrated in the following Examples, about the part which is common in the already-existing prior art and Example, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
FIG. 4 is a schematic sectional side view of the soldering apparatus 10 according to the present embodiment. As shown in FIG. 4, the soldering apparatus 10 according to this embodiment includes a plurality of magnetic bodies 41, 41, 41... And a plurality of magnetic bodies 41, 41, 41. Drive means 51, 51, 51..., And within the induction coil 11, the distance between each of the magnetic bodies 41, 41, 41. · 51 · 51 · · · can be changed by.

The drive means 51, 51, 51... Are actuators such as electric motors and air cylinders, and are driven and controlled by a control means (not shown) to raise and lower the magnetic bodies 41, 41, 41. The operator inputs in advance to the control means the location where the magnetic bodies 41, 41, 41... Are arranged in the vicinity of the heating plate 42, and the drive means 51, 51, 51. Based on the above, the magnetic bodies 41, 41, 41. As described above, it is possible to suppress the amount of current and the amount of heat generated at the portion where the magnetic bodies 41, 41, 41.
Further, by appropriately adjusting the distance of the magnetic bodies 41, 41, 41... Disposed in the vicinity of the heating plate 42 to the heating plate 42, the amount of current flowing through the portion of the heating plate 42 and the amount of generated heat can be suppressed. It is possible to adjust the degree.

  By configuring as described above, the distance between the magnetic body 41 and the workpiece 20 can be changed in any part of the workpiece 20, and the flow rate of the eddy current 102 generated in the heating plate 42 can be adjusted. The temperature at can be adjusted. That is, temperature unevenness on the heating plate 42 can be reduced, and soldering can be performed at a uniform temperature even when the size of the product to be heated is different, such as when the workpiece 20 is large.

  Further, depending on the arrangement of the circuit components 28 on the substrate 26, when the solder material 30 is also unevenly distributed according to the arrangement of the circuit components 28, such as a place where the circuit components 28 are densely packed and a place where the circuit components 28 are not densely, heating is necessary. The temperature rise of the workpiece 20 can be suppressed by bringing the magnetic body 41 close to the workpiece 20 in a place where there is no gap and reducing the flow rate of the eddy current 102. Furthermore, it is possible to change the distance between the magnetic body 41 and the workpiece 20 according to the characteristics of the solder material 30 and perform soldering at a temperature most suitable for the solder material 30 to be used.

[Example 3]
Next, a third embodiment of the soldering apparatus 10 according to the present invention will be described with reference to FIG.
FIG. 5 is a schematic sectional side view of the soldering apparatus 10 according to the present embodiment. As shown in FIG. 5, the soldering apparatus 10 according to the present embodiment includes temperature detection means 72, 72, 72... For detecting the surface temperature of the work 20, and the temperature detection means 72, 72, 72,. Calculating means for calculating whether or not the surface temperature detected in step S is equal to or higher than a predetermined set value set in advance, and if the surface temperature is determined to be higher than the set value by the calculating means, The body 41, 41, 41... And the heating plate 42 are configured to be close to each other by the driving means 51, 51, 51.

  Specifically, the temperature detection means 72, 72, 72,... Are, for example, non-contact thermometers, and the calculation means is disposed in a control device (for example, a personal computer or a PLC) 71, such as a CPU. It is a processing device. The temperature detecting means 72, 72, 72... Are connected to the control device 71, and the control device 71 is connected to driving means 51, 51, 51. The magnetic bodies 41, 41, 41.

According to the soldering method configured as described above, the surface temperature of the workpiece 20 is detected by the temperature detection means 72, 72, 72... (Temperature detection step). Then, the calculation means calculates whether the surface temperature detected by the temperature detection means is equal to or higher than a preset predetermined value (calculation step). When the calculation means determines that the surface temperature is equal to or higher than a set value, the driving means 51, 51, 51,... Determines the distance between the magnetic bodies 41, 41, 41. It can be brought closer (driving process).
In this case, the magnetic body 41 disposed at a location corresponding to the temperature detection means 72 whose surface temperature is determined to be equal to or higher than the set value is driven by the drive means 51 so that the distance to the heating plate 42 is reduced.

  By configuring as described above, the control unit 71 controls the magnetic body 41 located in a portion where the temperature is high (for example, the central portion 42a) or the like so as to approach the workpiece 20 using the driving unit 51, The magnetic flux density in the vicinity of the part can be lowered. As a result, the flow rate of the eddy current 102 generated in the heating plate 42 can be reduced, and the temperature in the workpiece 20 can be adjusted.

1 is a schematic sectional side view of a soldering apparatus according to Embodiment 1 of the present invention. The schematic side view which similarly showed magnetic flux distribution around the heating plate which concerns on this invention. The schematic bottom view which showed the generation | occurrence | production state of the eddy current in the heating plate which concerns on Example 1 of this invention. The schematic sectional side view of the soldering apparatus which concerns on Example 2 of this invention. The schematic sectional side view of the soldering apparatus which concerns on Example 3 of this invention. The schematic sectional side view of the soldering apparatus by a structure of a prior art. The schematic sectional side view which showed the generation | occurrence | production state of the magnetic flux around the workpiece | work by a prior art similarly. The schematic bottom view which similarly showed the generation | occurrence | production state of the eddy current in the heating plate by a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Soldering device 11 Induction coil 12 Winding 14 Conveyor 20 Work 24 Positioning jig 26 Substrate 28 Circuit component 30 Solder material 41 Magnetic body 42 Heating plate 42a High temperature part 51 Driving means 61 Current control device 71 Control device 72 Non-contact thermometer 100 magnetic flux 102 eddy current

Claims (4)

Having an induction coil into which a workpiece configured by installing a substrate on which a circuit component is placed via a solder material on a heating plate as a first magnetic body is inserted;
An AC magnetic field generated by applying an AC current to the induction coil induces and heats a heating plate of a workpiece placed in the induction coil to melt the solder material, and solders the circuit component to the substrate. A soldering device configured to be attached,
A second magnetic body different from the heating plate is disposed near the heating plate in the induction coil.
The soldering apparatus characterized by the above-mentioned. The soldering apparatus includes a plurality of the second magnetic bodies, and a plurality of driving means that individually raise and lower the second magnetic bodies,
In the induction coil, the distance between each second magnetic body and the heating plate can be changed by the driving means,
The soldering apparatus according to claim 1, wherein: The soldering device includes temperature detecting means for detecting a surface temperature of the workpiece;
A calculation means for determining whether the surface temperature detected by the temperature detection means is equal to or higher than a predetermined set value set in advance,
When the surface temperature is determined to be equal to or higher than a set value by the calculation unit, the distance between the second magnetic body and the heating plate is configured to be closer to the driving unit.
The soldering apparatus according to claim 2, wherein: Inserting a workpiece configured by installing a circuit board on which a circuit component is placed on a heating plate as a first magnetic body through a solder material, into an induction coil,
A soldering method configured to inductively heat the heating plate to melt the solder material and to solder the circuit component to the substrate by an alternating magnetic field generated by applying an alternating current to the induction coil. ,
The soldering method includes a temperature detection step of detecting the surface temperature of the workpiece,
A calculation step for calculating whether the surface temperature detected in the temperature detection step is equal to or higher than a predetermined set value set in advance;
A plurality of second magnetic bodies different from the heating plate are arranged in the induction coil near the heating plate, and when the surface temperature is determined to be equal to or higher than a set value by the calculation step, A driving step for reducing the distance between the magnetic body and the heating plate;
The soldering method characterized by the above-mentioned.

Images