JPWO2010064428A1 - Reflow furnace - Google Patents

Abstract

It is possible to reliably provide a temperature profile suitable for each of a plurality of types of printed circuit boards of different types. A furnace body 0 having a heater 1 and a printed circuit board conveyance path 30 that extends in the longitudinal direction of the furnace body 0 inside the furnace body 0 and above the heater 1 are provided. The conveyance path 30 includes a first conveyance conveyor 31 and a second conveyance conveyor 32. The first transport conveyor 31 includes a chain 33 and a chain 34, and the second transport conveyor 32 includes a chain 35 and a chain 36. The printed board conveyance speed by the first conveyance conveyor 31 and the printed board conveyance speed by the second conveyance conveyor 32 are set to different speeds. Thereby, the temperature profile suitable for each of a plurality of types of printed circuit boards of different types can be reliably provided.

Description

  The present invention relates to a reflow furnace that performs soldering by melting solder materials such as solder paste, solder balls, and solder bumps.

  In general, when soldering a printed circuit board, an electronic component, or the like (hereinafter collectively referred to as “printed circuit board” in the present specification) by melting a solder material, it is often performed in a reflow furnace. In the reflow furnace, a tunnel-like muffle is composed of a preheating zone, a main heating zone, and a cooling zone. A heater is installed in the preheating zone and the main heating zone, and a cooler is installed in the cooling zone. A printed circuit board on which soldering is performed is conveyed by a conveyance path. This conveyance path is provided above the heater, and is composed of a conveyance conveyor that extends over the longitudinal direction of the furnace body of the reflow furnace.

  Conventional reflow furnaces have one transfer path, but in order to improve productivity, reflow furnaces having two transfer paths have been proposed. For example, in Patent Document 1, two side conveyors whose installation positions are variable in the width direction of the furnace body are arranged on both sides of the center conveyor fixedly arranged in the width direction of the furnace body, and the same type of printed circuit boards are conveyed simultaneously. The invention is disclosed.

  Further, in Patent Document 2, two brackets whose installation positions are variable in the furnace body width direction are arranged on both sides of one bracket whose installation position is variable in the furnace body width direction, and the moving speed of the two brackets is further increased. An invention is disclosed in which a temperature profile suitable for each of different types of printed circuit boards is provided by making it variable.

  Further, in Patent Document 3, the first movable rail and the second movable rail whose installation positions are variable in the furnace body width direction are arranged on one side of the fixed rail fixedly arranged in the furnace body width direction. An invention has been disclosed in which the width of a printed circuit board that can be transported is increased to increase the transport efficiency of the printed circuit board.

  On the other hand, the heater used for the reflow furnace generally includes an infrared heater and a hot air blowing heater. Infrared type heaters penetrate the inside of printed circuit boards and electronic equipment and melt the solder paste applied to the soldering part, but since the infrared rays go straight, There is a problem that the soldered portion that becomes the gap cannot be heated sufficiently.

  On the other hand, the hot air blowing heater convects hot air inside the muffle, so the hot air enters the shadows of electronic components and narrow gaps, so the entire printed circuit board is heated more uniformly than the infrared heater. It has the feature that it can be used, and is used in many reflow furnaces today.

  There are two types of hot air blowing heaters installed in the reflow furnace, one that blows hot air from a wide area blowing port and one that blows hot air from many holes. A hot air blowing heater that blows out hot air from a large area blowing port has a low flow rate of hot air, so that the heating efficiency is not so good when it hits a printed circuit board.

  On the other hand, the hot air blowing heater that blows out hot air from a large number of holes can heat the hot air efficiently because the hot air speed is high and the hot air enters the back side of the surface mount component. For this reason, hot air blowers used in reflow furnaces often have many holes. The heater described below is a hot air blowing heater having a large number of holes unless otherwise specified.

  In the reflow furnace, the printed circuit board is heated in the order of preheating and main heating. In this preheating, the printed board is heated slowly with hot air at a low temperature to acclimate the printed board to heat, and the solvent in the solder paste is volatilized. However, if the preheating is performed with a large amount of hot air at a high temperature, the printed circuit board may be deformed by a heat shock, or electronic components may be blown away. Therefore, preheating in the reflow furnace is preferably performed with hot air having a low temperature and less than the main heating.

  The printed circuit board gets used to the heat by preheating, the solvent in the solder paste is volatilized, and the electronic components are firmly fixed to some extent, and then heated by the main heating in the reflow furnace. In this main heating, soldering is performed by blowing hot hot air to melt the solder powder in the solder paste. When the amount of hot air blown to the printed circuit board by this main heating is larger than the amount of hot air by preheating, the temperature rise can be accelerated. During the main heating, if the heating time at a high temperature becomes long, the printed circuit board and the electronic component are thermally damaged, and thus heating is performed in a short time.

  Generally, in a reflow furnace, a large number of hot air blowing heaters are installed at the upper and lower portions of a preheating zone and a main heating zone. For example, if the preheating zone is 5 zones, 10 hot air blowing heaters are installed above and below, and if the heating zone is 3 zones, 6 hot air blowing heaters are installed above and below, so one reflow furnace Then, upper and lower 16 hot air blowing heaters are installed.

  In the preheating zone and the main heating zone, the flow rate of the hot air blown from each hot air blowing heater is controlled so as to obtain a temperature profile suitable for the printed circuit board. The flow rate of the hot air is controlled by changing the rotational speed of the motor. As a motor used in a reflow furnace, there are many inverter motors that can easily control the rotation speed.

  By the way, simply controlling the speed of the hot air in the preheating and the main heating to uniformly heat the entire printed circuit board cannot eliminate poor soldering and thermal damage to the electronic components. In other words, the printed circuit board may be mounted with high-density mounting parts where electronic components are concentrated and power transistors with high heat capacity, transformers, etc. A lot of heat is needed. In addition, a single printed circuit board may include a soldering portion that requires a large amount of heat and a weak heat-resistant electronic component that causes thermal damage or functional deterioration when a large amount of heat is sprayed. If such a mixed printed circuit board is simply heated uniformly over the entire printed circuit board, defective soldering and electronic components will be thermally damaged.

  For example, even if the entire printed circuit board is uniformly heated for a printed circuit board in which high-density mounting parts and weak heat-resistant electronic components are mixedly mounted, sufficient heating is required for high-density mounting parts that require a large amount of heat. The solder paste cannot be completely melted, or even if the solder paste is melted, the temperature of the soldering portion is low, so that the melted solder is not completely wetted and spread. Therefore, if the high-density mounting part is sufficiently heated, the weak heat-resistant electronic component is overheated, resulting in thermal damage and functional deterioration.

  In this way, when soldering a printed circuit board in which a soldered part that requires a large amount of heat and a weak heat-resistant electronic component are mounted with solder paste, the hot air blowing heater is soldered that requires a large amount of heat. The part where the part passes is made larger or the number of holes is increased, and on the other hand, the part where the weak heat-resistant electronic part passes is made smaller or less ( Patent Documents 4 and 5). Further, as another means, a hole where a weak heat-resistant electronic component passes has been closed (Patent Documents 6 to 8).

Japanese Utility Model Publication No. 3-44375 JP 10-163623 A JP 2005-59030 A Japanese Patent Laid-Open No. 10-284831 JP 2002-43733 A Japanese Patent Laid-Open No. 11-307927 JP 2000-124593 A JP 2001-144428 A

  Even with the inventions disclosed in Patent Documents 1 to 3, it is difficult to greatly vary the transport speeds of the two transport paths. In particular, in the invention disclosed in Patent Document 2, since the two conveyance paths share one bracket whose installation position is variable in the furnace body width direction, the temperature profile of the printed circuit board flowing through the two conveyance paths is It is not possible to deal with a large difference.

  In the inventions disclosed in Patent Documents 4 to 8, when a printed circuit board in which a soldering portion that requires a large amount of heat and a weak heat-resistant electronic component are mixed is soldered with a solder paste, high-density mounting is performed. Since the part is often biased to one side, both sides, or the center of the printed circuit board, the high-density mounting part can be efficiently heated by simply changing the hole size or number of holes for such a printed circuit board. I couldn't. As a result, in the conventional hot air blowing heater, the high-density mounting portion may be poorly soldered or the other portion may be thermally damaged. As described above, in the inventions disclosed in Patent Documents 4 to 8, it is difficult to reliably provide a temperature profile suitable for the printed circuit board. For this reason, even if the inventions disclosed in Patent Documents 4 to 8 are diverted, it is difficult to provide temperature profiles suitable for different types of printed circuit boards that are transported through the two transport paths.

  An object of the present invention is to provide a reflow furnace that can reliably provide a temperature profile suitable for each of a plurality of types of printed circuit boards of different types.

As a result of intensive studies to solve the above problems, the present inventor,
(A) In a reflow furnace equipped with a first transport conveyor and a second transport conveyor, the first transport conveyor is composed of a first rail and a second rail, and the second transport conveyor is a third transport conveyor. And the fourth rail, the printed board carrying speed by the first conveyor and the printed board carrying speed by the second conveyor can be set to different speeds, so that a plurality of different types can be set. It is possible to reliably provide a temperature profile suitable for each kind of printed circuit board, and (b) in the hot air blowing heater of the reflow furnace, the size of the hole drilled in one plate is stepless. To adjust to the other plate, the other plate in which the same hole as that of one plate is drilled is overlapped with one plate so that each hole matches, and the other plate is shifted. Knowing that the hole in one plate can be adjusted steplessly, and this makes it possible to more reliably provide a temperature profile suitable for each of multiple types of printed circuit boards. Completed.

  The present invention is a reflow furnace comprising a furnace body having a heater, and a printed circuit board conveyance path that extends in the longitudinal direction of the furnace body inside the furnace body and above the heater, wherein the conveyance path is: It consists of a first transfer conveyor arranged in parallel in the width direction of the furnace body and a second transfer conveyor different from the first transfer conveyor, and the first transfer conveyor is aligned in the width direction of the furnace body. A first rail for transporting the printed circuit board and a second rail, and a second transport conveyor arranged in parallel in the width direction of the furnace body for transporting the printed circuit board. A reflow furnace comprising a rail and a fourth rail, wherein the printed board conveyance speed by the first conveyor and the printed board conveyance speed by the second conveyor can be set to different speeds. is there. According to the present invention, it is possible to reliably provide a temperature profile suitable for each of a plurality of types of printed circuit boards of different types.

  In the reflow furnace according to the present invention, the installation position of at least one of the first rail and the second rail is variable in the width direction of the furnace body, and among the third rail and the fourth rail. It is desirable that at least one of the installation positions is variable in the width direction of the furnace body.

  In these reflow furnaces according to the present invention, the heater is a heater in which a large number of holes are formed in the hot air blowing plate, and the printed circuit board is heated by blowing hot air from the holes, and the heater is provided in the hot air blowing plate. The hot air adjusting plate in which the hole substantially the same as the hole of the hot air blowing plate is drilled in the same place as the hole, so that the hole drilled in the hot air blowing plate and the hole drilled in the hot air adjusting plate match It is desirable that the opening area of the hole of the hot air blowing plate can be adjusted by closely contacting the hot air blowing plate and moving the hot air adjusting plate along the hot air blowing plate. As a result, it is possible to more reliably provide temperature profiles suitable for different types of printed circuit boards.

  In this case, it is desirable that the hot air adjusting plate is composed of a plurality of components, and each of the plurality of components is independently movable with respect to the hot air blowing plate. The hot air adjusting plate covers the hot air blowing plate of the hot air blowing heater and may be one sheet, but may be divided into a plurality of sheets so that each can move independently. A single hot air adjustment plate is suitable for adjusting the hot air for each zone, and the one divided into multiple sheets is a print in which soldered parts that require a large amount of heat and weak heat-resistant electronic components are mixed. Suitable for substrate heating.

  Further, it is desirable that a blowing nozzle is attached to the hole of the hot air blowing plate. The hot air blowing plate used in the present invention may be simply a hole having a hole, but if a blowing nozzle is attached to the hole, the direction of the hot air becomes good and the printed circuit board can be efficiently heated. As the blowing nozzle, one blowing nozzle may be attached to one hole, or a plate-like object may be attached to a large number of holes, and an ejection port communicating with the hole may be formed in this plate-like object. . The plate-like blowing nozzle can be any plate shape such as a long straight shape, a short straight shape, a meandering shape, a zigzag shape, or the like.

  If a hot air suction port is formed near the hole in the blower plate, the hot air that has fallen in temperature when it hits the printed circuit board is immediately sucked in from the hot air suction port. Does not interfere with the balloon. As a result, in the reflow furnace in which the hot air blowing heater having such a structure is installed, turbulent flow does not occur in the furnace, and more efficient heating can be performed.

  When the reflow furnace is in operation, the hot air first passes through the hole of the hot air adjusting plate, and then passes through the hole of the hot air blowing plate and hits the printed circuit board to heat the printed circuit board. At this time, if the hot air adjusting plate and the hot air blowing plate are not in close contact with each other, the hot air that has passed through the hot air adjusting plate flows out from another hole of the hot air blowing plate and becomes a biased blowing. Therefore, when the reflow furnace is in operation, the hot air adjusting plate and the hot air blowing plate must be in close contact with each other, and the hot air adjusting plate can be moved along the hot air blowing plate when adjusting the opening area of the hole of the hot air blowing plate. It must be.

  It is desirable that the hot air adjusting plate has a screw attached and a long hole is formed in the hot air blowing plate at a position corresponding to the screw. That is, in order to allow the hot air adjusting plate and the hot air blowing plate to adhere to each other and to allow the hot air adjusting plate to move, a screw is erected on the hot air adjusting plate, and the hot air blowing plate that coincides with the screw has a hot air adjusting plate. A long hole that is longer in the moving direction is drilled. Thus, after passing the screw of the hot air adjusting plate through the long hole of the hot air blowing plate, the nut is screwed from the top of the screw. When the hot air adjusting plate is moved, the nut is not firmly tightened, but is set so that the hot air adjusting plate can be moved. After that, when the hot air adjusting plate is moved and the opening area of the hole of the hot air blowing plate becomes a predetermined size, the nut is firmly tightened to bring the hot air adjusting plate into close contact with the hot air blowing plate. In order to bring the hot air adjusting plate and the hot air blowing plate into close contact, a plurality of screws standing on the hot air adjusting plate are required. When another plate-like material is installed on the hot air blowing plate, a long hole is also drilled in this plate-like material, and a nut is screwed into the long hole of the plate-like material through a screw.

  In the present invention, the hot air blowing plate is adjusted along the hot air blowing plate to adjust the opening area of the hot air blowing plate. If it can be confirmed, there is no problem. However, when the hot air nozzle is attached to the hole of the hot air blowing plate, the hole area of the hole cannot be confirmed because the hole of the hot air blowing plate cannot be seen. In such a case, a scale capable of measuring the moving distance of the hot air adjusting plate is attached. As this scale, there is one in which a long hole is formed in a portion where a screw protrudes and a scale is attached to a side portion of the long hole. Then, the moving distance of the screw is measured with respect to this scale. In addition, as the scale, a bar material may be erected on the hot air adjusting plate, a long hole may be formed in a portion where the bar material protrudes, and the long hole may be graduated.

  The movement of the hot air adjusting plate may be performed by the user's hand, but when it is performed by hand, an accurate moving distance cannot be obtained. Therefore, if the hot air adjusting plate is accurately moved, rotation of the screw is suitable. As an example of the rotation of the screw, the screw is rotatably attached to the hot air adjusting plate, and the female screw into which the screw is screwed is fixed to the main body of the hot air blowing heater or the hot air blowing plate. When the hot air adjusting plate is moved, when the screw is rotated, the screw moves relative to the fixed female screw, and the hot air adjusting plate attached with the screw moves little by little.

  According to the present invention, the conveyance speed of the printed circuit board by the first conveyance conveyor and the conveyance speed of the printed circuit board by the second conveyor can be set to different speeds. A reflow furnace capable of reliably providing a suitable temperature profile can be provided.

  Furthermore, according to the present invention, the amount of hot air in each zone can be changed without using an expensive inverter motor, the high-density mounting part can be efficiently heated, and the work of adjusting the size of the holes is extremely difficult. A reflow furnace that can be easily performed can be provided.

  Conventional reflow furnaces do not allow adjustment of the holes in the hot air blowing plate, so various types of hot air blowing plates with holes suitable for the printed circuit board are prepared. In order to change to a board or to make a hole suitable for a printed circuit board, it was necessary to perform a laborious process of closing the hole each time. The opening area of the hole of the hot air blowing plate can be easily adjusted by moving it a little. Therefore, for multiple types of printed circuit boards with greatly different temperature profiles, or printed circuit boards with high-density mounting parts, the hot air blowing plate hole where the part where the high temperature profile is to pass passes through is enlarged. By opening and blowing a large amount of hot air, sufficient heating can be performed, and other holes that do not require a large amount of heat can be made small to prevent overheating.

  In the preheating zone consisting of multiple zones, the ideal temperature profile suitable for the printed circuit board can be obtained by changing the hole size with respect to the traveling direction of the printed circuit board, and there is no soldering failure or thermal damage. In addition to obtaining a soldered portion, the present invention has an excellent effect not found in conventional reflow furnaces in that there is no scattering of small parts and small-diameter balls.

It is a perspective view which extracts and decomposes | disassembles the principal part of the furnace body of the reflow furnace which concerns on this invention, and simplifies and shows a part. 3 is a block diagram illustrating a configuration example of a control system of a conveyance path 30. FIG. 3 is a plan view illustrating a configuration example of a conveyance path 30. FIG. 3 is a front view illustrating a configuration example of a conveyance path 30. FIG. 2 is a front sectional view showing a configuration example of a hot air blowing heater 1. FIG. It is side surface sectional drawing which shows the structural example of the hot air blowing heater. It is an enlarged bottom view which shows the example of arrangement | positioning of the hot air adjustment board 20 and the hot air blowing board 14. FIG. 4 is a bottom view showing a configuration example of a hot air adjusting plate 20. FIG. It is explanatory drawing which shows the temperature profile example of the reflow furnace which concerns on this invention. It is explanatory drawing which shows the temperature profile example of the reflow furnace of a comparative example.

The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a perspective view showing a main part of a furnace body 0 of a reflow furnace according to the present invention, extracted and disassembled, and a part simplified. As shown in FIG. 1, the reflow furnace according to the present invention includes a furnace body 0 having a hot air blowing heater (hereinafter referred to as heater 1) and a conveyance path 30. The conveyance path 30 is located inside the furnace body 0 and above the heater 1 by a predetermined distance from the upper surface of the heater 1, so that the longitudinal direction of the furnace body 0 (the same direction as the conveyance direction X of the printed board in FIG. 1). ) Is placed and arranged.

  The conveyance path 30 includes a first conveyance conveyor 31 that is an example of a first conveyance unit, and a second conveyance conveyor 32 that is an example of a second conveyance unit. As shown in FIG. 1, the 1st conveyance conveyor 31 and the 2nd conveyance conveyor 32 are arranged in parallel in the width direction of the furnace body 0 (direction orthogonal to the conveyance direction X of the printed circuit board in FIG. 1 in a horizontal surface). The In the present invention, the first conveyor 31 and the second conveyor 32 are independent of each other.

  The first transport conveyor 31 includes a first chain (hereinafter referred to as a chain 33) that is an example of a first rail and a second chain (hereinafter referred to as a chain 34) that is an example of a second rail. Is done. The chain 33 and the chain 34 are juxtaposed in the width direction of the furnace body 0, and transport the printed circuit board by moving in the transport direction X of the printed circuit board at the same speed. The chain 33 and the chain 34 are configured to be able to move endlessly by a well-known and commonly used first transport drive mechanism (for example, an endless drive mechanism including a chain, a sprocket wheel, a drive motor, a control device, and the like). There is no need to use a drive mechanism having a specific structure.

  As indicated by the double-headed arrow shown in FIG. 1, the chain 34 is configured to be able to change its installation position in the width direction of the furnace body 0 by the first moving mechanism. As a result, various printed circuit boards having different dimensions can be transported by the first transport conveyor 31.

  On the other hand, the second conveyor 32 includes a third chain (hereinafter referred to as a chain 35) which is an example of a third rail and a fourth chain (hereinafter referred to as a chain 36) which is an example of a fourth rail. Consists of. The chain 35 and the chain 36 are juxtaposed in the width direction of the furnace body 0, and transport the printed circuit board by moving in the transport direction X of the printed circuit board at the same speed. The chain 35 and the chain 36 are also moved endlessly by a second transport drive mechanism (for example, an endless drive mechanism including a chain, a sprocket wheel, a drive motor, a control device, etc.) independent of the well-known and commonly used first transport drive mechanism. It is only necessary to be configured so that a drive mechanism having a specific structure is not necessary.

  As shown by the double-headed arrow shown in FIG. 1, the chain 36 is configured to be able to change its installation position in the width direction of the furnace body 0 by the second moving mechanism. As a result, various printed circuit boards having different dimensions can be transported by the second transport conveyor 32.

  FIG. 2 is a block diagram illustrating a configuration example of a control system of the conveyance path 30. As shown in FIG. 2, the control system for the transport path 30 includes an operation unit 80 and a control unit 81. The operation unit 80 is an input device such as a touch panel type liquid crystal display or a keyboard, and is operated by a user to set the temperature of the heater 1, the width of the first transfer conveyors 31 and 32, and the transfer speed. It is. When the user inputs the temperature of the heater 1, the widths and the transport speeds of the first transport conveyor 31 and the second transport conveyor 32, etc., the operation unit 80 receives the temperature of the heater 1, the first transport conveyor 31 and the first transport conveyor 31. The setting information D for individually setting the width and the conveying speed of the second conveyor 32 is generated, and the generated setting information D is output to the control unit 81.

  A control unit 81 is connected to the operation unit 80. The control unit 81 controls the first and second transport driving mechanisms and the first and second moving mechanisms described above based on the setting information D input to the operation unit 80.

  A motor for driving the chains 33 and 34 (hereinafter referred to as motor M1) is provided in the first transport driving mechanism, and a motor for driving the chains 35 and 36 (hereinafter referred to as motor M1) is provided in the second transport driving mechanism. 1 is provided, the first moving mechanism is provided with a motor (hereinafter referred to as motor M3) for moving the chain 34 in the double-headed arrow shown in FIG. 1, and the second moving mechanism is provided with the second moving mechanism. A motor (hereinafter referred to as motor M4) for moving the chain 36 in the double-headed arrow shown in FIG. 1 is provided.

  Motors M1, M2, M3, and M4 are connected to control unit 81. The control unit 81 generates drive information D1, D2, D3, D4 based on the setting information D, and the motors M1, M2, M3, M4 rotate based on the generated drive information D1, D2, D3, D4. To drive.

  For example, the drive information D1 includes information for rotationally driving the motor M1 so that the drive speed of the chains 33 and 34 is driven at 0.7 m / min. The drive information D2 includes information for rotationally driving the motor M2 such that the drive speed of the chains 35 and 36 is driven at 1.0 m / min. The drive information D3 includes information for rotationally driving the motor M3 that moves the chain 34 so that the distance between the chain 33 and the chain 34 matches the width of the first printed circuit board. The drive information D4 includes information for rotationally driving the motor M4 that moves the chain 36 so that the distance between the chain 35 and the chain 36 matches the width of the second printed circuit board.

  Thus, since the control part 81 controls each of the motors M1, M2, M3, and M4 based on the setting information D, the conveyance path 30 is controlled by the first conveyance conveyor 31 and the second conveyance path. The conveyance speed of the printed circuit board by the conveyance conveyor 32 can be set to a different speed so that the width of the printed circuit board conveyed by the first conveyance conveyor 31 and the width of the printed circuit board conveyed by the second conveyance conveyor 32 are different. Can be set.

  FIG. 3 is a plan view showing a configuration example of the conveyance path 30, and FIG. 4 is a front view thereof. 3 and 4, the motors M1 and M2 are omitted for convenience of explanation. As described above, the conveyance path 30 includes the first conveyance conveyor 31 having the chains 33 and 34 and the second conveyance conveyor 32 having the chains 35 and 36.

First, it will be described that the first transport conveyor 31 and the second transport conveyor 32 transport printed boards at different transport speeds.
As shown in FIGS. 3 and 4, the first transport drive mechanism for driving the chains 33 and 34 is a first chain sprocket wheel (hereinafter referred to as a first sprocket wheel 37), a second chain sprocket. A wheel (hereinafter referred to as a second sprocket wheel 38) and a motor M1 (not shown) are included. In the first transport drive mechanism, the control unit 81 outputs drive information D1 based on the setting information D from the operation unit 80 shown in FIG. Transport by.

  The chain 33 is driven by a first sprocket wheel 37 and the chain 34 is driven by a second sprocket wheel 38. The first and second sprocket wheels 37 and 38 are connected to the motor M1, and the first and second sprocket wheels 37 and 38 are rotated at the same speed by the rotational drive of the motor M1, and the printed circuit board is shown in FIG. The chains 33 and 34 are driven so as to be conveyed in the conveying direction X shown in FIG.

  The second transport drive mechanism for driving the chains 35 and 36 includes a third chain sprocket wheel (hereinafter referred to as a third sprocket wheel 39), a fourth chain sprocket wheel (hereinafter referred to as a fourth sprocket wheel 40). The motor M2 (not shown). In the third transport drive mechanism, the control unit 81 outputs drive information D2 based on the setting information D from the operation unit 80 and rotationally drives the motor M2, thereby transporting the printed circuit board at a desired transport speed.

  The chain 35 is driven by a third sprocket wheel 39, and the chain 36 is driven by a fourth sprocket wheel 40. The third and fourth sprocket wheels 39, 40 are connected to the motor M2, and the third and fourth sprocket wheels 39, 40 are rotated at the same speed by the rotational drive of the motor M2, and the printed circuit board is shown in FIG. The chains 35 and 36 are driven so as to be conveyed in the conveying direction X shown in FIG.

  Thus, since the 1st conveyance conveyor 31 has a 1st conveyance drive mechanism and the 2nd conveyance conveyor 32 has a 2nd conveyance drive mechanism, the conveyance speed of the printed circuit board by the 1st conveyance conveyor 31 is obtained. In addition, the printed board conveyance speed by the second conveyance conveyor 32 can be set to a different speed.

  Accordingly, the first printed circuit board having the first temperature profile is heated by the first transport conveyor 31 and the second transport profile 32 has a second temperature profile different from the first temperature profile. In the case of heating the second printed circuit board, the first printed circuit board has a first speed by appropriately setting the transport speed of the first transport conveyor 31 and the transport speed of the second transport conveyor 32 to be different. It is possible to reliably give the temperature profile and reliably give the second temperature profile to the second printed circuit board.

Next, it will be described that the first transport conveyor 31 and the second transport conveyor 32 transport printed boards having different widths.
A first fixing plate 41 is provided on the chain 33 in parallel with the conveying direction of the chain 33. The chain 34 is provided with a first moving plate 42 parallel to the transport direction of the chain 34. The chain 35 is provided with a second fixing plate 43 parallel to the transport direction of the chain 35. The chain 36 is provided with a second moving plate 44 in parallel with the transport direction of the chain 36. Further, a motor fixing plate 45 is provided in the outer direction of the second moving plate 44 (the right direction in FIGS. 3 and 4).

  A slide shaft 51 is provided between the first fixed plate 41 and the motor fixed plate 45 via a first moving plate 42 and a second fixed plate 43. The first fixing plate 41, the second fixing plate 43, and the motor fixing plate 45 fix the slide shaft 51, and the first moving plate 42 and the second moving plate 44 slide along the slide shaft 51. Move.

  First, the conveyance path 30 on the first conveyance conveyor 31 side will be described. A first screw shaft 52 is provided between the first fixed plate 41 and the motor fixed plate 45 via a first moving plate 42. The first screw shaft 52 has a threaded portion, and engages with the first moving plate 42 by the threaded portion. The first screw shaft 52 rotates together with the rotation of the first variable width shaft for changing the distance between the chain 33 and the chain 34, and moves the first moving plate 42 in the direction of the arrow Y1. Incidentally, the first fixing plate 41, the second fixing plate 43, the motor fixing plate 45 and the second moving plate 44 are penetrated so as not to contact the first screw shaft 52.

  In order to rotate the first screw shaft 52, a motor M <b> 3 is provided on a fixed plate 64 extending from the first fixed plate 41. The motor M3 is provided with a motor pulley (hereinafter referred to as a first pulley 61), and the motor M3 rotates the first pulley 61. A shaft pulley (hereinafter referred to as a second pulley 62) is provided above the first pulley 61, and a first drive belt 63 is wound around the first pulley 61 and the second pulley 62. . That is, when the first pulley 61 rotates by driving the motor M3, the second pulley 62 also follows and rotates via the first drive belt 63. A first variable width shaft 54 is provided at the center of the second pulley 62. The first screw shaft 52 is provided at the tip of the first variable width shaft 54 via the first fixed plate 41.

  When the user wants to change the distance between the chain 33 and the chain 34 in accordance with the width of the printed board conveyed by the first conveyor 31, first, the user uses the operation unit 80 to provide information on the width of the printed board (for example, the board width). 70mm etc.). Then, the setting information D is output from the operation unit 80 to the control unit 81, and the control unit 81 outputs drive information D3 to the motor M3. Based on the drive information D3 output from the controller 81, the motor M3 is rotationally driven to rotate the first pulley 61, and the second pulley 62 connected via the first drive belt 63 is rotated. . The first variable width shaft 54 and the first screw shaft 52 are rotated by a predetermined number by the rotation of the second pulley 62.

  Since the first screw shaft 52 has a threaded portion as described above and this threaded portion is engaged with the first moving plate 42, the first screw shaft 52 rotates with the first screw shaft 52. The first moving plate 42 slides (moves) along the slide shaft 51 in the direction of the arrow Y1. The amount of movement of the first moving plate 42 is based on the width of the printed circuit board previously input to the input device by the user. Thereby, the distance between the chain 33 and the chain 34 can be changed in accordance with the width of the printed circuit board conveyed by the first conveyor 31.

  Next, the conveyance path 30 on the second conveyance conveyor 32 side will be described. A second screw shaft 53 is provided between the first fixed plate 41 and the motor fixed plate 45 via a second moving plate 44. The second screw shaft 53 has a threaded portion, and is engaged with the second moving plate 44 by the threaded portion. The second screw shaft 53 rotates with the rotation of the second variable width shaft 55 for changing the distance between the chain 35 and the chain 36, and moves the second moving plate 44 in the direction of the arrow Y2. Incidentally, the first fixed plate 41, the second fixed plate 43, the motor fixed plate 45 and the second moving plate 44 are penetrated so as not to contact the second screw shaft 53.

  In order to rotate the second screw shaft 53, a motor M <b> 4 is provided on a fixed plate 74 extending from the motor fixed plate 45. The motor M4 is provided with a motor pulley (hereinafter referred to as a third pulley 71), and the motor M4 rotates the third pulley 71. A shaft pulley (hereinafter referred to as a fourth pulley 72) is provided below the third pulley 71, and a second drive belt 73 is wound around the third pulley 71 and the fourth pulley 72. . That is, when the third pulley 71 rotates by driving the motor M4, the fourth pulley 72 also follows and rotates. A second variable width shaft 55 is provided at the center of the fourth pulley 72. The above-described second screw shaft 53 is provided at the tip of the second variable width shaft 55 via a motor fixing plate 45.

  When it is desired to change the distance between the chain 35 and the chain 36 in accordance with the width of the printed board transported by the second transport conveyor 32, first, the user inputs information on the width of the printed board using the operation unit 80. Then, setting information D is output from the operation unit 80 to the control unit 81, and the control unit 81 outputs drive information D4 to the motor M4. Based on the drive information D4 output from the control unit 81, the motor M4 is rotationally driven to rotate the third pulley 71, and the fourth pulley 72 connected via the second drive belt 73 is rotated. . Then, by the rotation of the fourth pulley 72, the second variable width shaft 55 and the second screw shaft 53 rotate by a predetermined number.

  Since the second screw shaft 53 has a threaded portion as described above and this threaded portion is engaged with the second moving plate 44, the second screw shaft 53 is rotated along with the rotation of the second screw shaft 53. The moving plate 44 slides (moves) along the slide shaft 51 in the direction of the arrow Y2. The amount of movement of the second moving plate 44 is based on the width of the printed board previously input by the user to the input device. Thereby, the distance between the chain 35 and the chain 36 can be changed according to the width of the printed circuit board conveyed by the second conveyor 32.

  Thus, since the distance between the chain 33 and the chain 34 can be changed and the distance between the chain 35 and the chain 36 can be changed, the width of the printed board conveyed by the first conveyor 31 and the second conveyor The width of the printed circuit board conveyed by the conveyor 32 can be set differently.

  FIG. 5 is a front sectional view showing a configuration example of the heater 1, and FIG. 6 is a side sectional view thereof. As shown in FIGS. 5 and 6, the hot air blowing type heater 1 used in the reflow furnace of the present invention is installed in the upper and lower parts of the furnace body 0 of the reflow furnace. The heater 1 described in FIG. 6 will be described up and down as seen in FIGS. 5 and 6 assuming that it is installed below the furnace body 0 of the reflow furnace.

  The heater 1 is box-shaped, and has a blower chamber 2, a heating chamber 3, a hot air chamber 4, and a suction chamber 5 from below in the vertical direction. A blower 6 is disposed in the center of the blow chamber 2. For example, a sirocco fan is used as the blower 6 and is driven by a motor 7 provided outside. The motor 7 is not an expensive inverter motor but a normal inexpensive motor. As shown in FIGS. 5 and 6, there are partition walls 8 (one is not shown) on both sides of the air blowing chamber 2, and one end of the partition wall is an opening 9. The opening of each partition is not at a position facing each other, but at both ends.

  In the heating chamber 3, channels 10 and 10 are formed on both sides, and a plurality of electric heaters 11 are disposed inside the heating chamber 3. A suction hole 13 is formed in the partition plate 12 that separates the heating chamber 3 and the blower chamber 2. The suction hole 13 is disposed immediately above the blower 6 and its diameter is slightly smaller than the diameter of a sirocco fan that is a blower.

  The hot air chamber 4 communicates with the opening 9 of the air blowing chamber 2 described above, and hot air is sent from the air blowing chamber 2. A hot air blowing plate 14 is stretched between the hot air chamber 4 and the suction chamber 5, and the suction chamber 5 communicates with the heating chamber 3 through flow paths 10 and 10. A heater surface 15 is formed above the suction chamber 5.

  A number of holes 16 are formed in the hot air blowing plate 14, and a blowing nozzle 17 is attached to each of the holes 16. As shown in FIG. 1, the blowout nozzle 17 of this example is a zigzag plate, and the plate-like blowout nozzle 17 is provided with a jet outlet 18 communicating with the hole 16 of the hot air blowout plate. The blowing nozzle 17 is erected so as to protrude from the heater surface 15. The plate-like blowing nozzle 17 is installed in a direction crossing the traveling direction (conveying direction X) of the printed board. On both sides of the plate-like blowing nozzle 17, zigzag suction ports 19 are formed along the blowing nozzle.

  FIG. 7 is an enlarged bottom view showing an arrangement example of the hot air adjusting plate 20 and the hot air blowing plate 14. As shown in FIG. 7, a hot air adjusting plate 20 is disposed in close contact with the lower surface of the hot air blowing plate 14. The hot air adjusting plate 20 has a hole 21 having substantially the same shape at the same position as the hole 16 of the hot air blowing plate 14.

  FIG. 8 is a bottom view showing a configuration example of the hot air adjusting plate 20. As shown in FIG. 8, the hot air adjusting plate 20 is divided into three constituent members (20A, 20B, 20C) along the traveling direction (conveying direction X) of the printed circuit board, and each constituent member is indicated by an arrow a. , B and c are configured to be movable.

  The hot air adjusting plate 20 is provided with screws 22. Slots 23 and 24 are formed in the hot air blowing plate 14 and the heater surface 15 at the same position as these screws 22. A scale 25 is attached to the side of the long hole 24 of the heater surface 15. At all times, the screw 22 is inserted into the long holes 23 and 24, and a nut 26 is screwed from above.

  As described above, according to the reflow furnace of the present invention, the first printed circuit board having the first temperature profile is heated by the first transfer conveyor 31 and the first transfer conveyor 32 is used to heat the first printed circuit board. When heating a second printed circuit board having a second temperature profile different from the temperature profile, the transport speed of the first transport conveyor 31 and the transport speed of the second transport conveyor 32 are set differently. Therefore, the first temperature profile can be reliably given to the first printed circuit board and the second temperature profile can be reliably given to the second printed circuit board. By doing so, it is possible to provide an optimum temperature profile for each of the first printed circuit board and the second second printed circuit board. Since it is, to illustrate this point.

  The electric heater 11 provided in the heating chamber 3 of the heater 1 is energized, and the motor 7 is driven to rotate the sirocco fan as the blower 6. Then, the gas in the heating chamber 3 is heated by the electric heater 11 and becomes hot hot air, and is drawn into the blower chamber 2 from the suction hole 13 of the blower 6 by the blower 6. The hot air drawn into the blower chamber 2 is sent to the blower chamber 2 through the opening 9 from the blower side of the blower by the blower 6, passes through the hole 21 of the hot air adjustment plate 20 and the hole 16 of the hot air blower plate 14, and It blows out from the jet outlet 18 of the blowing nozzle 17.

  The hot air blown out from the jet outlet 18 hits the first printed circuit board transported by the first transport conveyor 31 and the second printed circuit board transported by the second transport conveyor 32, and the first printed circuit board is transported to the first printed circuit board. The printed circuit board and the second printed circuit board are heated. In the first printed circuit board and the second printed circuit board heated by hot air, the solder paste applied to the soldering portion is melted, and the first printed circuit board or the second printed circuit board and the electronic component are soldered. The

  Here, when the temperature of the first printed circuit board is desired to be higher than the temperature of the second printed circuit board, the conveying speed of the first conveying conveyor 31 is made higher than the conveying speed of the second conveying conveyor 32. In addition to setting it low, a hole 16 of a hot air blowing plate corresponding to the first printed board, for example, a hot air blowing plate corresponding to the hot air adjusting plate 20A shown in FIG. Keep the hole in the hot air blowing plate corresponding to.

That is, the opening area of the hole 21 of the hot air adjusting plate 20A corresponding to the portion that requires a large amount of heat is made to completely coincide with the hole 16 of the hot air blowing plate 14 so that the opening area of the hole 21 of the hot air adjusting plate 20A is sufficient. The hot air adjusting plates 20B and 20C corresponding to portions that do not require a large amount of heat are moved slightly in the directions of arrows b and c to reduce the opening area of the holes 16 of the hot air blowing plate 14. .

  Thus, when the opening area of the hole 16 of the hot air blowing plate 14 is adjusted by the hot air adjusting plate 20, the opening area of the hole 16 of the hot air blowing plate 14 is increased from the portion that requires a large amount of heat. A large amount of hot air blows out, and the first printed circuit board can be heated to a temperature sufficiently higher than that of the second printed circuit board.

  Since the hot air blown from the plate-like nozzle is deprived of heat by the first printed circuit board and the second printed circuit board, the temperature decreases. The hot air whose temperature has been lowered is sucked from the suction port 19 in the vicinity where the plate-like blowing nozzle 17 is erected, and enters the heating chamber 3 through the flow path 10. The hot air that has entered the heating chamber 3 is heated to a predetermined temperature by the electric heater 11 and sucked into the blower chamber 2 by the blower 6. Then, the hot air is sent from the opening 9 to the hot air chamber 4 and is blown again from the outlet 18 of the blowing nozzle 17 to heat the first printed board and the second printed board.

  Thus, according to the reflow furnace which concerns on this invention, since the conveyance speed of the printed circuit board by the 1st conveyance conveyor 31 and the conveyance speed of the printed circuit board by the 2nd conveyance conveyor 32 can be set to a different speed | rate. Thus, a temperature profile suitable for each of a plurality of types of printed circuit boards can be reliably provided.

  In the above description, the chains 33 and 35 provided on the first fixed plate and the second fixed plate 43 are fixedly arranged in the width direction of the furnace body 0, and the first moving plate 42 and the second moving plate 42 However, the present invention is not limited to this embodiment, and at least one of the chain 33 and the chain 34 is not limited thereto. The installation position may be variable in the width direction of the furnace body, and the installation position of at least one of the chain 35 and the chain 36 may be variable in the width direction of the furnace body.

For example, with respect to the width direction of the furnace body 0, a fixed plate is provided on the chain 33 and the chain 36, and a movable plate is provided on the chains 34 and 35, or a movable plate is provided. The chain 33, 34, 35 may be provided with a moving plate and may be movably arranged. As described above, the moving plate is moved by a driving device such as a motor, a transmission mechanism such as a pulley and a belt that transmits the rotation of the motor shaft, a screw shaft that is rotated by the transmission mechanism, and the like.
In the present embodiment, the movement of the first moving plate 42 and the second moving plate 44 has been described as being performed by a motor according to the width of the printed board to be conveyed. The variable shaft 54 or the second variable width shaft 55 may be operated so as to be manually adjusted. Accordingly, the motor M3, the first pulley 61, the second pulley 62, the first drive belt 63, the fixed plate 64, the motor M4, the third pulley 71, the fourth pulley 72, and the second drive belt 73. And the manufacturing cost of a conveyance path can be reduced by deleting the fixed plate 74.

The reflow furnace according to the present invention will be specifically described with reference to a temperature profile.
The first printed circuit board and the second printed circuit board having different temperature profiles were soldered using the reflow furnace according to the present invention shown in FIGS. 1 to 8 and the reflow furnace of the comparative example. The reflow furnace of the comparative example is obtained by removing the function of setting the transport speeds of the first transport conveyor 31 and the second transport conveyor 32 from the reflow furnace according to the present invention and the hot air adjusting plate 20. . Moreover, the board | substrate dimension has changed thickness, the thickness of the 1st printed circuit board is 1 mm, and the thickness of the 2nd printed circuit board is 5 mm.

  A solder paste mixed with powder of Sn-3Ag-0.5Cu (melting temperature: 217 to 219 ° C.) was applied to the soldering portion of the printed circuit board. In both the reflow furnace according to the present invention and the reflow furnace of the comparative example, the temperature of the preheating zone is set to 150 to 180 ° C. at the operation unit 80, and the temperature of the main heating zone is set to 220 ° C. or higher (the peak temperature is 230 to 250 ° C.). Set. The operation unit 80 was set to heat the printed circuit board for 60 to 100 seconds in the preheating zone and for 30 to 60 seconds in the main heating zone. And the thermocouple was made to contact the 1st and 2nd printed circuit board, and the temperature of the printed circuit board was measured.

  Both hot air blowing plates have a diameter of 4 mm, and 50 holes are formed in a zigzag line in a zigzag position that crosses the direction of travel of the printed circuit board. Then, 10 zigzag rows are arranged in the traveling direction of the printed circuit board, and the total number of holes is 500.

  In the reflow furnace according to the present invention, the operation unit 80 sets the conveyance speed of the first conveyance conveyor 31 to 0.7 m / min and the conveyance speed of the second conveyance conveyor 32 to 1.0 m / min. Set. On the other hand, in the reflow furnace of the comparative example, the operation speed of both the first conveyor 31 and the second conveyor 32 was set to 1.0 m / min by the operation unit 80.

  As the hot air blowing heater, a hot air adjusting plate divided into three parts in the traveling direction of the printed board was used. The hole of the hot air blowing plate corresponding to the first printed circuit board is aligned with the hole of the hot air blowing plate, the hole of the hot air blowing plate is completely opened, and the other hot air adjusting plate is moved. The hole of the hot air blowing plate corresponding to this hot air adjusting plate is made small.

  FIG. 9 is an explanatory view showing a temperature profile example of the reflow furnace according to the present invention in which the heating temperature and the conveyance speed are set as described above. As shown in FIG. 9, the vertical axis represents the temperature of the printed circuit board, and the horizontal axis represents the elapsed time (transport time) after the printed circuit board is placed in the reflow furnace.

  The 1st printed circuit board conveyed with the 1st conveyance conveyor 31 has the characteristic of the temperature profile L1. That is, the first printed circuit board reaches 150 ° C. to 180 ° C., which is the preset temperature of the preheating zone, when the conveyance time is about 90 (sec) to about 175 (sec). The second printed circuit board reaches 220 ° C., which is the set temperature of the main heating zone, when the transport time is about 205 (sec) to about 255 (sec).

  The 2nd printed circuit board conveyed with the 2nd conveyance conveyor 32 has the characteristic of the temperature profile L2. That is, the second printed circuit board reaches 150 ° C. to 180 ° C., which is the preset temperature of the preheating zone, when the conveyance time is about 180 (sec) to about 260 (sec). The first printed circuit board reaches 220 ° C. or higher, which is the set temperature of the main heating zone, when the conveyance time is about 320 (sec) to about 365 (sec).

  Both the first printed circuit board and the second printed circuit board soldered in this reflow furnace are sufficiently wetted with solder, there is no soldering failure, and electronic components in other soldered parts are not It was not burnt or discolored.

  As described above, the reflow furnace according to the present invention reserves both the first printed circuit board transported by the first transport conveyor 31 and the second printed circuit board transported by the second transport conveyor 32 as a spare. In the heating zone, heating is performed at a set temperature of 150 to 180 ° C. for a set time of 60 to 100 seconds, and in this heating zone, heating is performed at a set temperature of 220 ° C. or more for a set time of 30 to 60 seconds. Thereby, temperature profiles suitable for different types of printed circuit boards can be provided, and soldering can be performed reliably.

  FIG. 10 is an explanatory view showing a temperature profile example of a reflow furnace of a comparative example in which the heating temperature and the conveyance speed are set as described above. As shown in FIG. 10, the vertical axis represents the temperature of the printed circuit board, and the horizontal axis represents the elapsed time (transport time) after the printed circuit board is placed in the reflow furnace.

  The 1st printed circuit board conveyed with the 1st conveyance conveyor 31 has the characteristic of the temperature profile L3. That is, the first printed circuit board reaches 150 ° C. to 180 ° C., which is the preset temperature of the preheating zone, when the conveyance time is about 90 (sec) to about 175 (sec). In addition, the first printed circuit board reaches 220 ° C., which is the set temperature of the main heating zone, when the conveyance time is about 205 (sec) to about 255 (sec) (the temperature profile L3 is the temperature described above). It is substantially the same as the profile L1.)

  The 2nd printed circuit board conveyed with the 2nd conveyance conveyor 32 has the characteristic of the temperature profile L4. That is, the second printed circuit board reaches 150 ° C. to 180 ° C., which is the preset temperature of the preheating zone, when the conveyance time is about 150 (sec) to about 190 (sec). Further, the second printed circuit board cannot reach 220 ° C. or higher which is the set temperature of the main heating zone.

  In addition, the first printed circuit board soldered in the reflow furnace can be soldered without defects because the temperature profile L3 is high as described above. However, in the second printed circuit board, the main heating is performed. Since it did not reach 220 ° C. in the zone, the solder was not melted and soldering could not be performed.

  Thus, in the reflow furnace of the comparative example, an appropriate temperature profile could be given to the first printed board, but an appropriate temperature profile could not be given to the second printed board.

DESCRIPTION OF SYMBOLS 0 ... Reflow furnace body, 1 ... Hot air blowing heater, 14 ... Hot air blowing plate, 15 ... Heater surface, 16 ... Hole of hot air blowing plate, 17 ... Blowing nozzle, 18 ... Spout, 19 ... Suction port, 20 ... Hot air adjusting plate, 21 ... Hot air adjusting plate hole, 22 ... Screw, 23, 24 ... Long hole, 25 ... Scale, 26 ... nut, 30 ... transport path, 31 ... first transport conveyor, 32 ... second transport conveyor, 33 ... first chain, 34 ... first 2 chain 35 ... third chain 36 ... fourth chain 37 ... first chain sprocket wheel 38 ... second chain sprocket wheel 39 ... Third chain sprocket wheel, 40... Fourth chain Sprocket wheel, 41 ... first fixed plate, 42 ... first moving plate, 43 ... second fixed plate, 44 ... second moving plate, 45 ... side surface Plate, 51... First slide shaft, 52... Second slide shaft, 53... First screw shaft, 54... Second screw shaft, 61. Pulley, 62 ... first screw shaft pulley, 63 ... first drive belt, 71 ... second motor pulley, 72 ... second screw shaft pulley, ..Second drive belt, 80 ... operation unit, 81 ... control unit

Claims (8)

A reflow furnace comprising: a furnace body having a heater; and a printed circuit board conveyance path that extends in the longitudinal direction of the furnace body inside the furnace body and above the heater,
The transport path includes a first transport conveyor arranged in parallel in the width direction of the furnace body, and a second transport conveyor different from the first transport conveyor,
The first transport conveyor includes a first rail and a second rail that are arranged in parallel in the width direction of the furnace body to transport the printed circuit board, and the second transport conveyor includes the furnace body. Comprising a third rail and a fourth rail arranged side by side in the width direction for transporting the printed circuit board,
A reflow furnace characterized in that the conveyance speed of the printed circuit board by the first conveyance conveyor and the conveyance speed of the printed circuit board by the second conveyor can be set to different speeds.   The installation position of at least one of the first rail and the second rail is variable in the width direction of the furnace body, and the installation position of at least one of the third rail and the fourth rail. The reflow furnace according to claim 1, which is variable in a width direction of the furnace body. A furnace body having a heater for heating the printed circuit board;
Provided in the furnace body, juxtaposed in the transport direction of the printed circuit board, and transports the printed circuit board at a predetermined transport speed;
An operation unit that generates setting information for individually setting the conveyance speeds of the first and second conveyance units;
A reflow furnace comprising: a control unit that receives the setting information generated by the operation unit and drives the first and second transfer units based on the received setting information. The first transport unit includes a first rail and a second rail that are arranged in parallel in the width direction of the furnace body and transport the printed circuit board.
The second transport unit includes a third rail and a fourth rail that are arranged in parallel in the width direction of the furnace body and transport the printed circuit board.
The installation position of at least one of the first rail and the second rail is variable in the width direction of the furnace body, and the installation position of at least one of the third rail and the fourth rail. The reflow furnace according to claim 3, which is variable in a width direction of the furnace body.   The heater is a heater in which a large number of holes are formed in a hot air blowing plate, and the printed circuit board is heated by blowing hot air from the hole, and the hot air is blown into the same place as the hole formed in the hot air blowing plate. The hot air adjusting plate in which substantially the same hole as the hole of the blowing plate is drilled is made to match the hole drilled in the hot air blowing plate and the hole drilled in the hot air adjusting plate. 5. The opening area of the hole of the hot air blowing plate can be adjusted by bringing the hot air adjusting plate into close contact with the blowing plate and moving the hot air adjusting plate along the hot air blowing plate. 6. The reflow furnace described in item 1.   The reflow furnace according to claim 5, wherein the hot air adjusting plate includes a plurality of constituent members, and each of the plurality of constituent members is independently movable with respect to the hot air blowing plate.   The reflow furnace according to claim 5 or 6, wherein a blowing nozzle is attached to a hole of the hot air blowing plate.   The screw is attached to the said hot air adjustment board, and the long hole is drilled in the hot air blowing board of the position which corresponds to this screw, The any one of Claim 5-7 characterized by the above-mentioned. Reflow furnace described in 1.

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