JP6799443B2 - Transport heating device - Google Patents

Description

The present invention relates to a transfer heating device that can be applied to, for example, a reflow device that reflows a printed circuit board.

A reflow device is used in which a solder composition is supplied in advance to an electronic component or a printed circuit board, and the substrate is conveyed into a reflow furnace by a conveyor. The reflow device includes a conveyor that conveys a substrate and a heating furnace that supplies a body to be heated, for example, a printed circuit board, by the conveyor (Patent Document 1). The heating furnace is divided into a plurality of zones along a transport path from the carry-in port to the carry-out port, and these plurality of zones are arranged in an in-line manner. The plurality of zones have roles such as a heating zone and a cooling zone depending on their functions.

The heating furnace body usually has an upper pot (upper furnace body) and a lower pot (lower furnace body). For example, hot air is blown from the upper pot to the substrate, and hot air is blown from the lower pot to the substrate to melt the solder in the solder composition and solder the electrodes of the printed circuit board and the electronic components. Soldering. In the reflow device, the desired soldering is performed by controlling the heating temperature according to the desired temperature profile.

JP-A-2007-173494

In recent years, there has been an increasing demand for a reflow device called a 3D-MID (Molded Interconnect Device) that can be used for processing a three-dimensional molded circuit component having a three-dimensional shape. Generally, a reflow device for a printed wiring board has a limitation on the height of a substrate that can be conveyed, and it is difficult to flexibly cope with the height. In particular, many 3D-MID parts have a higher overall height than those mounted on a printed wiring board, and the technology disclosed in Prior Art Document 1 has the height of recent 3D-MID parts and the like. It is difficult to respond more flexibly to high-quality workpieces. Further, in a general reflow device for a printed wiring board, there is an increasing demand for a reflow device that can be used not only for processing flat workpieces but also for processing various objects to be heated such as three-dimensional molded circuit parts.

Therefore, an object of the present invention is to provide a transport heating device that can flexibly respond to a heated body having various shapes according to the height of the heated body.

In the present invention, a transport device for transporting a heated body, a first furnace body provided either above or below the transport device, and above or below the transport device are arranged facing the first furnace body. It is provided with a second furnace body, an elevating mechanism for raising and lowering either the first furnace body or the second furnace body, and a closing member for closing the gap between the first furnace body and the second furnace body . The first furnace body and the second furnace body are opened with different opening areas on the surfaces facing each other, and the outer surface of either the first furnace body or the second furnace body and the first furnace body or the second furnace body are opened. It is a transport heating device provided so that the inner surface of any one of the two is in contact with each other via a closing member and overlaps with each other.

According to at least one embodiment, it is possible to flexibly treat the heated body having various shapes according to the height of the heated body. The effects described herein are not necessarily limited, and may be any of the effects described in the present disclosure. In addition, the content of the present disclosure is not construed as limited by the effects exemplified in the following description.

It is a schematic diagram which shows the outline of the conventional reflow apparatus to which this invention is applied. It is a front view sectional view which shows the state of the reflow device which concerns on this invention. It is a front view sectional view which shows the state which raised the upper furnace body of the reflow device which concerns on this invention. It is a front view sectional view which shows the state which raised the upper furnace body of the reflow device which concerns on this invention. It is a front view sectional view which shows the modification of the reflow device which concerns on this invention.

Hereinafter, embodiments of the present invention will be described. The explanation will be given in the following order.
<1. Configuration of reflow device>
<2. Modification example>
It should be noted that one embodiment described below is a preferred specific example of the present invention and is provided with various technically preferable limitations, but the scope of the present invention is particularly limited to the present invention in the following description. Unless otherwise stated, the invention is not limited to these embodiments.

<1. Configuration of reflow device>
FIG. 1 shows a schematic configuration of a conventional reflow device 101 to which the present invention can be applied. The reflow device 101 includes a furnace body 102 and a printed circuit board (hereinafter referred to as a work W) in which surface mount electronic components are mounted on both sides of a heated body, or a three-dimensional molded circuit component M having a three-dimensional shape (FIG. 3). It is provided with a transport conveyor 103 for passing (shown) and the like through the furnace body 102, rotating bodies 105a, 105b, 105c, 105d, a hood 106, and a control unit (not shown) that define the movement path of the transport conveyor 103.

The furnace body 102 is for heating the heated body from above and below by the lower furnace body 111 and the upper furnace body 112, and cooling after heating. The transfer conveyor 103 is one transfer conveyor extending in the transfer direction in the case of single transfer, and two transfer conveyors arranged in parallel in the transfer direction in the case of dual transfer. The conveyor 103 corresponds to a conveyor in the claims. For example, a roller chain is used as the conveyor 103.

The reflow device 101 includes a lower housing 104 that covers the entire lower portion and a hood 106 that covers the entire upper portion. The hood 106 is placed on the lower housing 104, and the entire furnace body 102 is surrounded by the hood 106 on the lower housing 104 to form a closed space. The hood 106 has a structure in which a metal plate (outer plate) is attached to the hood frame.

The body to be heated (work W in FIG. 1) is carried into the furnace body 102 from the carry-in port 107, and then is conveyed by the transfer conveyor 103 in the arrow direction (from left to right toward FIG. 1) at a predetermined speed. Finally, it is taken out from the carry-out port 108. Although not shown, a carry-in device for carrying in the heated body is provided in the front stage of the carry-in inlet 107, and a carry-out device for sending out the heated body to the outside is arranged in the rear stage of the carry-out outlet 108.

The furnace body 102 is sequentially divided into, for example, nine zones Z1 to Z9 along the transport path from the carry-in inlet 107 to the carry-out outlet 108, and these zones Z1 to Z9 are arranged in an in-line manner. The seven zones Z1 to Z7 from the carry-in inlet 107 side are heating zones, and the two zones Z8 and Z9 on the carry-out port 108 side are cooling zones. A forced cooling unit (not shown) is provided in connection with the cooling zones Z8 and Z9. The number of zones is an example, and other zones may be provided. The plurality of zones Z1 to Z9 control the temperature of the object to be heated according to the temperature profile at the time of reflow. Each of the heating zones Z1 to Z7 has a lower furnace body 111 including a blower and an upper furnace body 112, respectively.

The first section is the temperature rising section R1 where the temperature rises due to heating, the next section is the preheat (preheating) section R2 whose temperature is almost constant, the next section is the reflow (reflow) section R3, and the last section. The section is the cooling unit R4. The temperature rising section R1 is a period for heating the substrate from room temperature to the preheating section R2 (for example, 150 ° C. to 170 ° C.). The preheat portion R2 is a period for performing isothermal heating, activating the flux, removing the oxide film on the surface of the electrode and the solder powder, and eliminating uneven heating of the object to be heated. The reflow portion R3 (for example, 220 ° C. to 240 ° C. at the peak temperature) is a period during which the solder is melted and the bonding is completed. In the reflow section R3, it is necessary to raise the temperature to a temperature exceeding the melting temperature of the solder. The final cooling unit R4 is a period in which the printed circuit board is rapidly cooled to form a solder composition. In the case of lead-free solder, the temperature in the reflow section is higher (for example, 240 ° C. to 260 ° C.).

In the reflow device 101 having such a configuration, the zones Z1 and Z2 are mainly in charge of temperature control of the temperature raising unit R1. Zones Z3, Z4 and Z5 are mainly in charge of temperature control of the preheat unit R2. Zones Z6 and Z7 are in charge of temperature control of the reflow unit R3. Zone Z8 and Zone Z9 are in charge of temperature control of the cooling unit R4.

The control unit may be a personal computer connected to the reflow device 101, or may be composed of a CPU (Central Processing Unit), a memory, a hard disk drive, or the like provided in the reflow device 101. As will be described in detail later, the control unit controls the elevating operation of the upper furnace body 112 by the elevating mechanism 170, the expansion and contraction of the closing member 160, and other parts and the whole of the reflow device 101.

In the present embodiment, in the above-mentioned reflow device 101, the state of the reflow device 101 can be changed because the upper furnace body 112 of the furnace body 102 is configured to be able to move up and down. By changing the state of the reflow device 101, it is possible to process various types of objects to be heated having different heights.

FIG. 2 is a cross-sectional view of a cross section of one of the heating zones cut along a plane orthogonal to the transport direction as viewed from the carry-in inlet side. In the state shown in FIG. 2, a thin flat plate-shaped work W as an example of the heated body is placed on the conveyor 103 and conveyed in the facing gap between the lower furnace body 111 and the upper furnace body 112. The lower furnace body 111 is configured as a rectangular box body that opens upward. The upper furnace body 112 is configured as a rectangular box body that opens downward.

In the present embodiment, the lower furnace body 111 corresponds to the first furnace body according to claim 3, and the upper furnace body 112 corresponds to the second furnace body according to claim 3. The upper furnace body 112 has a larger opening area than the lower furnace body 111. As a result, the side surface of the lower furnace body 111 and the side surface of the upper furnace body 112 overlap each other, and the upper furnace body 112 is provided so as to cover the lower furnace body 111. By increasing the opening area of the upper furnace body 112 located above and allowing the upper furnace body 112 to cover the lower furnace body 111, it is possible to prevent dust and the like from entering the furnace body.

A heat-resistant packing 121 is provided on the end surface of the upper furnace body 112 that abuts on the lower furnace body 111. An inverted conical protrusion 131 is formed on the upper surface of the upper furnace body 112, and a hole 141 into which the protrusion 131 is fitted is provided in the frame of the hood 106. The protrusion 131 is a contact portion where the upper furnace body 112 acts on the hood 106.

The space formed by the lower furnace body 111 and the upper furnace body 112 is filled with an atmospheric gas such as nitrogen (N ₂ ) gas. The atmospheric gas may be an atmospheric gas instead of the nitrogen (N ₂ ) gas. The lower furnace body 111 and the upper furnace body 112 heat the work W by ejecting hot air (heated atmospheric gas) to the work W. The lower furnace body 111 is provided with, for example, a blower having a turbofan configuration, a heater, and a lower heating unit 151 including a panel (heat storage member) having a large number of small holes through which hot air passes. Further, the upper furnace body 112 is provided with, for example, a blower having a turbofan configuration, a heater, and an upper heating unit 152 including a panel (heat storage member) having a large number of small holes through which hot air passes. In the present invention, it is also possible to provide the heating unit only on one of the lower furnace body 111 and the upper furnace body 112.

The closing member 160 is provided so as to intervene in the gap between the lower furnace body 111 and the upper furnace body 112. The closing member 160 is a tubular member made of an elastic body such as heat-resistant rubber. The closing member 160 is formed in a ring shape and is provided so as to come into contact with the entire outer peripheral surface of the lower furnace body 111 and the entire inner peripheral surface of the upper furnace body 112. The closing member 160 is connected to a gas injection device (not shown) or the like, and closes the gap between the lower furnace body 111 and the upper furnace body 112 by injecting an inert gas such as nitrogen or a gas such as air to expand it. To do. As a result, the atmosphere inside the furnace body 102 composed of the lower furnace body 111 and the upper furnace body 112 can be maintained in a constant state.

The closing member 160 is in a contracted state in which the gas inside is evacuated when the reflow device 101 is not operating and during the ascending / descending operation of the upper furnace body 112. As a result, friction and the like do not interfere with the ascending / descending operation and maintenance of the upper furnace body 112.

The reflow device 101 includes an elevating mechanism 170 for elevating and lowering the upper furnace body 112. The elevating mechanism 170 includes a bracket 171, a motor (not shown), a screw shaft 172, and a rotation transmission mechanism unit 173. The elevating mechanism 170 can elevate and elevate the upper furnace body 112 and the hood 106 while maintaining a parallel state with respect to the bottom surface of the lower housing 104.

The elevating operation of the upper furnace body 112 by the elevating mechanism 170 is controlled by the control unit. Under the control of the control unit, the upper furnace body 112 can be moved up and down by the elevating mechanism 170 according to the height of the body to be heated and stopped at an arbitrary position. Further, the user of the reflow device 101 may operate the elevating mechanism 170 or the control unit to elevate the upper furnace body 112 to an arbitrary position and stop it. Further, the elevating mechanism 170 may have its own control function, and the elevating mechanism 170 may elevate the upper furnace body 112 to a position corresponding to the height of the heated body.

Brackets 171 are fixed to both side surfaces of the upper furnace body 112 of the furnace body 102, respectively. Two brackets 171 are attached to the upper furnace body 112 at equidistant positions from the work W carry-in side, and two brackets (not shown) are attached at equidistant positions from the work carry-out side. That is, the bracket 171 is attached near the four corners of the upper furnace body 112. The bracket 171 is formed with a female screw-shaped hole so that the screw shaft 172 can mesh with the inside thereof, and is fixed to the side surface of the upper furnace body 112.

The elevating mechanism 170 includes a motor as a single driving means. The rotation of the motor is controlled by a control unit (not shown). The furnace body 102 thermally expands by several millimeters during the reflow operation as compared with the non-operation. The position of the bracket 171 changes due to the thermal expansion of the furnace body 102. In order to absorb this change, it is preferable that the horizontal plate of the bracket 171 is slidable at the attachment points of the bracket 171 and the elevating mechanism 170.

The reflow device 101 includes the same number of screw shafts 172 as the bracket 171, and the screw shafts 172 are provided so as to be inserted into the bracket 171. The surface of the screw shaft 172 is formed in a male screw shape for engaging with a female screw shape hole in the bracket 171. The inside of the bracket may be male-threaded, and the surface of the screw shaft 172 may be female-threaded.

The rotation transmission mechanism unit 173 is connected to the motor and the screw shaft 172, and is for transmitting the driving force of the motor to the screw shaft 172. The motor and the rotation transmission mechanism unit 173 are installed below the lower furnace body 111, for example, at the bottom of the reflow device 101. The farther away from the lower furnace body 111, the less affected by the heat of the furnace body at the time of reflow, so that the possibility that the motor and the rotation transmission mechanism unit 173 are damaged by heat can be reduced.

The rotation of the motor is transmitted to the screw shaft 172 by the rotation transmission mechanism unit 173. The rotation of the motor is transmitted to the rotation transmission mechanism unit 173, the rotation of the rotation transmission mechanism unit 173 is transmitted to the screw shaft 172, and the rotation of the screw shaft 172 causes the upper furnace body 112 to move up and down via the bracket 171. Since all the screw shafts 172 are connected to the rotation transmission mechanism unit 173, the left and right screw shafts 172 rotate in synchronization with the rotation transmission mechanism unit 173. As a result, the upper furnace body 112 can be moved up and down while maintaining a parallel state with respect to the bottom surface of the lower housing 104.

The meshing structure of the screw shaft 172 and the bracket 171 has a self-locking function, and the position of the upper furnace body 112 when the rotation of the screw shaft 172 is stationary is maintained. Therefore, it is not necessary to provide a brake mechanism on the motor and the rotation transmission mechanism unit 173. Since the brake mechanism is not provided, for example, by rotating the handle (not shown) in the event of a power failure, the screw shaft 172 can be rotated to move the upper furnace body 112 up and down.

The state of FIG. 2 is a state in which the upper furnace body 112 is lowered as compared with the state shown in FIGS. 3 and 4, and the protrusion 131 is not fitted with the hole 141. The hood 106 is placed on the lower housing 104, and the upper furnace body 112 is placed on the lower furnace body 111 with the packing 121 interposed therebetween.

Hot air is blown from the lower side to the work W conveyed by the transfer conveyor 103 by the lower heating unit 151 provided in the lower furnace body 111 as shown by an arrow in FIG. Further, the upper heating unit 152 provided in the upper furnace body 112 blows hot air onto the work W from above as shown by an arrow in FIG. In the heat treatment in the reflow device 101, the upper heating unit 152 and the work W to be heated should be as close as possible from the viewpoint of heating efficiency. Since the upper furnace body 112 can be raised and lowered, the upper heating unit 152 can be arranged at an optimum position to heat the work W.

Next, the transition of the state of the reflow device 101 will be described. FIG. 3 is a diagram showing a state in which the upper furnace body 112 is raised as compared with the state of FIG. FIG. 3 is a cross-sectional view of a cross section of one of the heating zones cut along a plane orthogonal to the transport direction as viewed from the carry-in inlet side. In FIG. 3, a three-dimensional molding circuit component M as an example of the heated body is placed on the conveyor 103 and conveyed in the facing gap between the lower furnace body 111 and the upper furnace body 112. Even in the state of FIG. 3, the side surface of the lower furnace body 111 and the side surface of the upper furnace body 112 overlap each other, and the upper furnace body 112 is provided so as to cover the lower furnace body 111.

In the state of FIG. 3, the upper furnace body 112 is raised by the elevating mechanism 170, and the space between the lower furnace body 111 and the upper furnace body 112 is wider than that in the state of FIG. As a result, it becomes possible to convey a heated body having a height higher than the work W, for example, a three-dimensional molding circuit component M on the transfer conveyor 103.

In the state of FIG. 3, the inverted conical protrusion 131 on the upper surface of the upper furnace body 112 is fitted into the hole 141 of the hood 106 by raising the upper furnace body 112.

In order to transition from the state of FIG. 2 to the state of FIG. 3, first, the closing member 160 is contracted so that the upper furnace body 112 can be raised and lowered. Then, the upper furnace body 112 is raised by the elevating mechanism 170. Then, when the amount of movement of the upper furnace body 112 reaches a predetermined amount, the protrusion 131 fits into the hole 141.

In this state, the space between the lower furnace body 111 and the upper furnace body 112 expands, and the three-dimensional molding circuit component M can be placed on the conveyor 103. In the state of FIG. 3, for example, the upper furnace body 112 may be raised so as to enable heating of the three-dimensional molded circuit component M having a height of at least about 150 mm. However, the height of 150 mm is just an example, and the height of the object to be heated is not limited to a constant value.

When the elevating mechanism 170 completes the ascent of the upper furnace body 112, gas is injected into the closing member 160 to expand the closing member 160. As a result, by closing the gap between the lower furnace body 111 and the upper furnace body 112, the atmospheric gas is prevented from leaking from the space formed by the lower furnace body 111 and the upper furnace body 112, and the atmosphere in the space is kept constant. You can keep it in that state.

Then, hot air is blown from the lower side to the three-dimensional molding circuit component M by the lower heating unit 151 provided in the lower furnace body 111 as shown by an arrow in FIG. Further, the upper heating unit 152 provided in the upper furnace body 112 blows hot air from the upper side to the three-dimensional molding circuit component M as shown by an arrow in FIG.

In the heat treatment in the reflow device 101, the upper heating unit 152 and the three-dimensional molding circuit component M to be heated should be as close as possible from the viewpoint of heating efficiency. Since the upper furnace body 112 can be raised and lowered, the upper heating unit 152 can be arranged at an optimum position to heat the three-dimensional molding circuit component M.

FIG. 4 is a diagram showing a reflow device 101 during maintenance. FIG. 4 is a cross-sectional view of a cross section of one of the heating zones cut along a plane orthogonal to the transport direction as viewed from the carry-in inlet side.

At the time of maintenance, the elevating mechanism 170 raises the upper furnace body 112 further above the state shown in FIG. 3, and the upper furnace body 112 pushes up the hood 106 to bring about the state shown in FIG. In this maintenance state, the first opening 201 formed between the lower furnace body 111 and the upper furnace body 112 along the extension direction of the furnace body 102, and the furnace body 102 between the lower housing 104 and the hood 106. A second opening 211 formed along the extension direction of the above is formed.

The atmosphere inside the furnace body 102 is discharged to the outside through the first opening 201, and the temperature inside the furnace body 102 can be rapidly lowered. Further, a second opening 211 for maintenance is formed between the lower housing 104 and the hood 106 on both sides of the furnace body 102 along the transport direction. Maintenance work such as flux removal can be performed through the second opening 211.

As described above, according to the present embodiment, by raising and lowering the upper furnace body 112, it becomes possible to flexibly respond to the heated body having various shapes according to the height of the heated body, and various types of heated bodies can be accommodated. The heated body can be treated. In the above-described embodiment, the work W and the three-dimensional molded circuit component M are exemplified as the heated body, but the heated body is not limited to them. The present invention can be applied to a body to be heated having any height, and the upper furnace body 112 can be raised and lowered according to the height of the body to be heated to perform heat treatment in an optimum state. it can.

<2. Modification example>
Although the embodiments of the present disclosure have been specifically described above, the present invention is not limited to the above-described embodiments, and various modifications based on the technical idea of the present disclosure are possible. For example, a chain may be used in addition to the shaft as the rotation transmission mechanism between the plurality of elevating mechanisms 170. Further, the number of the elevating mechanism 170 may be a number other than that of the above-described embodiment. Further, the present invention can be applied not only to the reflow device 101 but also to a heating device for curing the resin and the like.

In addition, the configurations, methods, processes, shapes, materials, numerical values, etc. mentioned in the above-described embodiments are merely examples, and different configurations, methods, processes, shapes, materials, numerical values, etc. are used as necessary. You may. In addition, the configurations, methods, processes, shapes, materials, numerical values, etc. of the above-described embodiments can be combined with each other without departing from the gist of the present disclosure.

In the embodiment, the opening area of the upper furnace body 112 is configured to be larger than the opening area of the lower furnace body 111, but the opening area of the lower furnace body 111 may be larger than the opening area of the upper furnace body 112. ..

Further, in the embodiment, the upper furnace body 112 is configured to be able to move up and down, but the lower furnace body 111 may be configured to be able to move up and down. Further, both the lower furnace body 111 and the upper furnace body 112 may be configured to be able to move up and down.

The packing 121 interposed between the lower furnace body 111 and the upper furnace body 112 is not limited to the position shown in the embodiment shown in FIG. 2 and may be provided at the position shown in FIG. It acts as a cushioning material by interposing between the lower furnace body 111 and the upper furnace body 112, and may be provided anywhere as long as the upper furnace body 112 can be stabilized.

The closing member 160 may be expanded by injecting a liquid in addition to the gas. Further, the closing member 160 is not limited to a tube-shaped member made of an elastic body such as rubber, and closes a gap between the lower furnace body 111 and the upper furnace body 112 such as a lip packing, a driving lid, and a film-like body. However, any material may be used as long as the space between the lower furnace body 111 and the upper furnace body 112 can be maintained in a constant state.

As long as the lower furnace body 111 and / or the upper furnace body 112 can be raised and lowered, the raising and lowering mechanism 170 is not limited to the one described in the embodiment and may have any configuration.

Not limited to the state of FIG. 2 and the state of FIG. 3 described above in the embodiment, the upper furnace body 112 can be raised and lowered to an arbitrary height by controlling the reflow device 101 by a user using a computer or the like. It may be configured as.

Three-dimensional molding The height of the circuit component M is detected by a sensor or the like, and the control unit or the like determines the lifting condition of the upper furnace body 112 based on the detection result, so that the work W or three-dimensional molding of various heights can be formed. It may be possible to cope with a heated body such as a circuit component M. Further, the raising degree of the upper furnace body 112 may be determined based on the detection result, and the upper furnace body 112 may be automatically raised by the control of a computer or the like.

101 ... Reflow device 103 ... Conveyor conveyor 111 ... Lower furnace body 112 ... Upper furnace body 160 ... Closing member 170 ... Elevating mechanism M ... Three-dimensional molding circuit part W ·····work

Claims (5)

A transport device that transports the body to be heated and
A first furnace body provided either above or below the transfer device, and
A second furnace body arranged above or below the transfer device and facing the first furnace body, and
An elevating mechanism for raising and lowering either the first furnace body or the second furnace body, and
A closing member that closes the gap between the first furnace body and the second furnace body, and
With
The first furnace body and the second furnace body are opened with different opening areas on the sides facing each other, and the outer surface of either the first furnace body or the second furnace body and the first furnace A transport heating device provided so that the inner surface of either the body or the second furnace body contacts and overlaps with each other via the closing member . The transfer heating device according to claim 1, wherein the opening area of the first furnace body and the second furnace body, whichever is provided above the transfer device, is larger. The first furnace body is provided below the transport device, the second furnace body is provided above the transport device, and the elevating mechanism raises and lowers the second furnace body according to claim 1 or 2. The transport heating device according to the description. The first or second furnace body can be moved up and down to an arbitrary position according to the height of the heated body and stopped by the elevating mechanism according to claim 1 or 2. Conveyance heating device. The transport heating device according to claim 1 , wherein the closing member is a tubular member that expands after the lifting operation by the lifting mechanism to close the space between the first furnace body and the second furnace body.

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