JP2018082112A - Transportation heating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transportation heating apparatus which can flexibly cope with a height of a heated body having various shapes.SOLUTION: A transportation heating apparatus includes a transportation apparatus which transports a heated body, a first furnace body provided either above or below the transportation apparatus, a second furnace body arranged above or below the transportation apparatus to face the first furnace body, and a lifting mechanism which moves up and down either one of the first furnace body or the second furnace body. The first furnace body and the second furnace body have an aperture with a face thereof facing each other having a different aperture area.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a conveyance heating apparatus that can be applied to, for example, a reflow apparatus that performs reflow of a printed circuit board.

  A reflow apparatus is used in which a solder composition is supplied in advance to an electronic component or a printed circuit board, and the board is transported to a reflow furnace by a transport conveyor. The reflow apparatus includes a conveyance conveyor that conveys a substrate, and a heating furnace that is supplied with an object to be heated, such as a printed circuit board, by the conveyance conveyor (Patent Document 1). For example, the heating furnace is divided into a plurality of zones along a transfer path from the carry-in port to the carry-out port, and the plurality of zones are arranged in-line. 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 hook to the board, and hot air is blown from the lower hook to the board, so that the solder in the solder composition is melted and the printed circuit board electrodes and electronic components are soldered. The In the reflow apparatus, desired soldering is performed by controlling the temperature during heating according to a desired temperature profile.

JP 2007-173494 A

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

  Accordingly, an object of the present invention is to provide a transport heating apparatus that can flexibly cope with a body to be heated having various shapes according to the height of the body to be heated.

  The present invention includes a transport device that transports a heated object, a first furnace body that is provided either above or below the transport device, and a first furnace body that is disposed above or below the transport device. The second furnace body and an elevating mechanism for raising and lowering either the first furnace body or the second furnace body, and the first furnace body and the second furnace body have different opening areas on opposite sides. It is the conveyance heating apparatus provided so that it may open and overlap.

  According to at least one embodiment, the object to be heated having various shapes can be processed flexibly according to the height of the object to be heated. Note that the effects described here are not necessarily limited, and may be any effects described in the present disclosure. In addition, the contents of the present disclosure are not construed as being limited by the exemplified effects in the following description.

It is a basic diagram which shows the outline of the conventional reflow apparatus which can apply this invention. It is front view sectional drawing which shows the state of the reflow apparatus which concerns on this invention. It is front view sectional drawing which shows the state which raised the upper furnace body of the reflow apparatus which concerns on this invention. It is front view sectional drawing which shows the state which raised the upper furnace body of the reflow apparatus which concerns on this invention. It is front view sectional drawing which shows the modification of the reflow apparatus which concerns on this invention.

Embodiments of the present invention will be described below. The description will be given in the following order.
<1. Configuration of Reflow Device>
<2. Modification>
The embodiment described below is a preferred specific example of the present invention, and various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. Unless otherwise stated, the present invention is not limited to these embodiments.

<1. Configuration of Reflow Device>
FIG. 1 shows a schematic configuration of a conventional reflow apparatus 101 to which the present invention can be applied. The reflow apparatus 101 includes a furnace body 102, a substrate to be heated, for example, a printed circuit board (hereinafter referred to as a work W) on which surface mounting electronic components are mounted, or a three-dimensional molded circuit component M having a three-dimensional shape (see FIG. 3). ) And the like, and a rotating body 105a, 105b, 105c, 105d for defining a moving path of the conveying conveyor 103, a hood 106, and a control unit (not shown).

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

  The reflow apparatus 101 includes a lower housing 104 that covers the entire lower portion and a hood 106 that covers the entire upper portion. A 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 configuration in which a metal plate (outer plate) is attached to the hood frame.

  The object to be heated (work W in FIG. 1) is carried into the furnace body 102 from the carry-in entrance 107 and is then conveyed by the conveyer 103 at a predetermined speed in the direction of the arrow (left to right as viewed in FIG. 1). Finally, it is taken out from the carry-out port 108. Although not shown, a carry-in device for carrying in the object to be heated is provided upstream of the carry-in entrance 107, and a carry-out device for sending the object to be heated to the outside is arranged behind the carry-out port 108.

  The furnace body 102 is sequentially divided into, for example, nine zones Z1 to Z9 along the conveyance path from the carry-in entrance 107 to the carry-out exit 108, and these zones Z1 to Z9 are arranged in an inline manner. Seven zones Z1 to Z7 from the carry-in port 107 side are heating zones, and two zones Z8 and Z9 on the carry-out port 108 side are cooling zones. A forced cooling unit (not shown) is provided in association with the cooling zones Z8 and Z9. The number of zones is an example, and other numbers of zones may be provided. Several zone Z1-Z9 controls the temperature of a to-be-heated body according to the temperature profile at the time of reflow. Each of the heating zones Z1 to Z7 has a lower furnace body 111 and an upper furnace body 112 each including a blower.

  The first section is a temperature raising portion R1 where the temperature rises due to heating, the next section is a preheating (preheating) portion R2 where the temperature is substantially constant, the next section is a reflow (reflow) portion R3, and the last section The section is the cooling unit R4. The temperature raising portion R1 is a period in which the substrate is heated from room temperature to a preheating portion R2 (for example, 150 ° C. to 170 ° C.). The preheating part R2 is a period for performing isothermal heating, activating the flux, removing the oxide film on the surface of the electrode and solder powder, and eliminating heating unevenness of the heated object. The reflow portion R3 (for example, 220 ° C. to 240 ° C. at the peak temperature) is a period in which the solder is melted and the joining is completed. In the reflow portion R3, the temperature needs to be raised to a temperature exceeding the melting temperature of the solder. The last cooling part 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 portion is higher (for example, 240 ° C. to 260 ° C.).

  In the reflow apparatus 101 having such a configuration, the zones Z1 and Z2 are mainly responsible for temperature control of the temperature raising portion R1. The zones Z3, Z4 and Z5 are mainly responsible for the temperature control of the preheating part R2. Zones Z6 and Z7 are responsible for temperature control of the reflow section R3. The zone Z8 and the zone Z9 are responsible for temperature control of the cooling unit R4.

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

  In the present embodiment, in the reflow apparatus 101 described above, the upper furnace body 112 of the furnace body 102 is configured to be movable up and down, so that the state of the reflow apparatus 101 can be changed. By changing the state of the reflow apparatus 101, it is possible to process various types of heated objects having different heights.

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

  In the present embodiment, the lower furnace body 111 corresponds to the first furnace body in claim 3, and the upper furnace body 112 corresponds to the second furnace body in claim 3. The upper furnace body 112 has a larger opening area than the lower furnace body 111. Thereby, the side surface of the lower furnace body 111 and the side surface of the upper furnace body 112 overlap, and the upper furnace body 112 is provided so as to cover the lower furnace body 111. Increasing the opening area of the upper furnace body 112 located above and covering the upper furnace body 112 with respect to the lower furnace body 111 can prevent dust and the like from entering the furnace body.

  A heat-resistant packing 121 is provided on an end surface of the upper furnace body 112 that is in contact with 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, for example, nitrogen (N ₂ ) gas that is an atmospheric gas. The atmospheric gas may be atmospheric gas instead of 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 a lower heating unit 151 including, for example, a blower configured as a turbo fan, a heater, and 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 an upper heating unit 152 including a blower having a turbo fan configuration, a heater, and 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 a heating unit only in one of the lower furnace body 111 and the upper furnace body 112.

  A closing member 160 is provided so as to be interposed in the gap between the lower furnace body 111 and the upper furnace body 112. The closing member 160 is a tube-shaped 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 contact 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 a gap between the lower furnace body 111 and the upper furnace body 112 by injecting and expanding an inert gas such as nitrogen or a gas such as air. To do. Thereby, the atmosphere in the furnace body 102 composed of the lower furnace body 111 and the upper furnace body 112 can be maintained in a constant state.

  When the reflow apparatus 101 is not in operation and the upper furnace body 112 is moved up and down, the closing member 160 is in a contracted state because the internal gas is extracted. Thereby, the raising / lowering operation and maintenance of the upper furnace body 112 are not hindered by friction or the like.

  The reflow apparatus 101 includes an elevating mechanism 170 for elevating 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 lower 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 raising / lowering operation of the upper furnace body 112 by the raising / lowering mechanism 170 is controlled by the control unit. The upper furnace body 112 can be raised and lowered according to the height of the object to be heated by the elevating mechanism 170 under the control of the control unit, and can be stopped at an arbitrary position. Further, the user of the reflow apparatus 101 may operate the elevating mechanism 170 or the control unit to raise and lower the upper furnace body 112 to an arbitrary position and stop it. Furthermore, the elevating mechanism 170 may have its own control function, and the elevating mechanism 170 may elevate and lower the upper furnace body 112 to a position corresponding to the height of the heated object.

  The 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 a position equidistant from the work W carry-in side, and two brackets (not shown) are attached to the upper furnace body 112 at a position equidistant from the work carry-out side. That is, brackets 171 are attached in the vicinity of the four corners of the upper furnace body 112. The bracket 171 is formed with a female screw hole so that the screw shaft 172 can be engaged with the bracket 171, and is fixed to a side surface of the upper furnace body 112.

  The lifting 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 expands by a few millimeters during reflow operation compared to when it does not operate. 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 configured to be slidable at the location where the bracket 171 and the lifting mechanism 170 are attached.

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

  The rotation transmission mechanism 173 is connected to the motor and the screw shaft 172, and transmits the driving force of the motor to the screw shaft 172. The motor and rotation transmission mechanism 173 is installed below the lower furnace body 111, for example, at the bottom of the reflow apparatus 101. The further away from the lower furnace body 111, the less affected by the heat of the furnace body at the time of reflow, it is possible to reduce the possibility that the motor and the rotation transmission mechanism 173 will break down due to heat.

  The rotation of the motor is transmitted to the screw shaft 172 by the rotation transmission mechanism 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 upper furnace body 112 is moved up and down via the bracket 171 as the screw shaft 172 rotates. Since all the screw shafts 172 are connected to the rotation transmission mechanism 173, the left and right screw shafts 172 rotate in synchronization with the rotation transmission mechanism 173. Accordingly, 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 structure in which the screw shaft 172 and the bracket 171 are engaged has a self-locking function, and the position of the upper furnace body 112 when the rotation of the screw shaft 172 stops is maintained. Therefore, it is not necessary to provide a brake mechanism in the motor and rotation transmission mechanism 173. Since the brake mechanism is not provided, for example, by rotating a handle (not shown) at the time of a power failure, the upper shaft body 112 can be moved up and down by rotating the screw shaft 172.

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

  Hot air is blown from the lower side to the workpiece W conveyed by the conveyor 103 by the lower heating unit 151 provided in the lower furnace body 111 as indicated by an arrow in FIG. Further, hot air is blown from the upper side to the workpiece W as shown by the arrow in FIG. 2 by the upper heating unit 152 provided in the upper furnace body 112. In the heat treatment in the reflow apparatus 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 moved up and down, the workpiece W can be heated by arranging the upper heating unit 152 at an optimum position.

  Next, the state transition of the reflow apparatus 101 will be described. FIG. 3 is a view showing a state where 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 when one zone of the heating zone is cut along a plane orthogonal to the transport direction, as viewed from the carry-in entrance side. In FIG. 3, a three-dimensional molded circuit component M as an example of an object to be heated is placed on a conveyor 103 and conveyed in a facing gap between a lower furnace body 111 and an upper furnace body 112. 3, the side surface of the lower furnace body 111 and the side surface of the upper furnace body 112 overlap so that the upper furnace body 112 covers 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 the state of FIG. 2. Thereby, it becomes possible to convey a heated object having a height higher than the workpiece W, for example, the three-dimensional molded circuit component M, on the conveyer 103.

  In the state of FIG. 3, as the upper furnace body 112 rises, the inverted conical protrusions 131 on the upper surface of the upper furnace body 112 are fitted in the holes 141 of the hood 106, respectively.

  In order to make a 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 moved up and down. Then, the upper furnace body 112 is raised by the lifting mechanism 170. Then, when the movement amount of the upper furnace body 112 reaches a predetermined amount, the protrusion 131 is fitted into the hole 141.

  In this state, a space between the lower furnace body 111 and the upper furnace body 112 is widened, and the three-dimensional molded circuit component M can be placed on the transport conveyor 103. In the state of FIG. 3, for example, the upper furnace body 112 may be raised so that the three-dimensional molded circuit component M having a height of about 150 mm can be heated. However, the height of 150 mm is merely an example, and the height of the object to be heated is not limited to a certain value.

  When the raising of the upper furnace body 112 is completed by the elevating mechanism 170, gas is injected into the closing member 160 to expand the closing member 160. This prevents the atmosphere gas from leaking from the space formed by the lower furnace body 111 and the upper furnace body 112 by closing the gap between 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 a state.

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

  In the heat treatment in the reflow apparatus 101, the upper heating unit 152 and the three-dimensional molded 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 moved up and down, the three-dimensional molded circuit component M can be heated by arranging the upper heating unit 152 at an optimal position.

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

  At the time of maintenance, the upper furnace body 112 is raised further than the state of FIG. 3 by the lifting mechanism 170, and the hood 106 is pushed up by the upper furnace body 112, so that the state shown in FIG. In this maintenance state, the furnace body 102 is provided between the first opening 201 formed between the lower furnace body 111 and the upper furnace body 112 along the extending direction of the furnace body 102, and the lower housing 104 and the hood 106. A second opening 211 formed along the extending direction is formed.

  The atmosphere in the furnace body 102 is discharged outside through the first opening 201, and the temperature in the furnace body 102 can be quickly lowered. Further, a second opening 211 for maintenance is formed between the lower housing 104 and the hood 106 on both sides along the conveying direction of the furnace body 102. 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 cope with the heated body having various shapes according to the height of the heated body. The object to be heated can be processed. In the above-described embodiment, the workpiece W and the three-dimensional molded circuit component M are exemplified as the body to be heated, but the body to be heated is not limited thereto. The present invention can be applied to an object to be heated having any height, and the upper furnace body 112 can be moved up and down in accordance with the height of the object to be heated to perform heat treatment in an optimum state. it can.

<2. Modification>
Although the embodiments of the present disclosure have been specifically described above, the present disclosure 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 lifting mechanisms 170. Further, the number of lifting mechanisms 170 may be other than the above-described embodiment. Further, the present invention is not limited to the reflow apparatus 101 but can be applied to a heating apparatus for curing a resin.

  The configurations, methods, steps, shapes, materials, numerical values, and the like given in the above-described embodiments are merely examples, and different configurations, methods, steps, shapes, materials, numerical values, and the like are used as necessary. May be. The configurations, methods, steps, shapes, materials, numerical values, and the like of the above-described embodiments can be combined with each other without departing from the gist of the present disclosure.

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

  In the embodiment, the upper furnace body 112 is configured to be movable up and down, but the lower furnace body 111 may be configured to be movable up and down. Furthermore, you may comprise both the lower furnace body 111 and the upper furnace body 112 so that raising / lowering is possible.

  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 such as FIG. 2, but may be provided at the position shown in FIG. It may be provided anywhere as long as it is interposed between the lower furnace body 111 and the upper furnace body 112 and functions as a cushioning material and can stabilize the upper furnace body 112.

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

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

  2 and 3 described above in the embodiment, the user can raise and lower the upper furnace body 112 to an arbitrary height by controlling the reflow device 101 using a computer or the like. You may comprise.

  The height of the three-dimensional molded circuit component M is detected by a sensor or the like, and the control unit or the like determines the lifting / lowering degree of the upper furnace body 112 based on the detection result. You may make it respond | correspond to to-be-heated bodies, such as the circuit component M. FIG. Further, the rising 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 control of a computer or the like.

DESCRIPTION OF SYMBOLS 101 ... Reflow apparatus 103 ... Conveyor 111 ... Lower furnace body 112 ... Upper furnace body 160 ... Closure member 170 ... Elevating mechanism M ... Three-dimensional molded circuit component W ·····work

Claims (6)

A transport device for transporting a heated object;
A first furnace body provided on either the upper side or the lower side of the transfer device;
A second furnace body disposed above or below the transfer device so as to face the first furnace body;
An elevating mechanism for elevating and lowering either the first furnace body or the second furnace body,
The said 1st furnace body and the said 2nd furnace body are the conveyance heating apparatuses provided so that the surface of the mutually opposing side might open with the opening area from which it differs, and to overlap. The conveyance heating apparatus according to claim 1, wherein an opening area of the first furnace body and the second furnace body which is provided above the conveyance apparatus is configured to be large. The first furnace body is provided below the transfer device, the second furnace body is provided above the transfer device, and the elevating mechanism moves the second furnace body up and down. The conveyance heating apparatus as described. The said raising / lowering mechanism can raise and lower the said 1st furnace body or the said 2nd furnace body to the arbitrary positions according to the height of the said to-be-heated body, and can stop it. Conveyor heating device. The conveyance heating apparatus according to any one of claims 1 to 3, further comprising a closing member that closes a gap between the first furnace body and the second furnace body. The conveyance heating apparatus according to claim 5, wherein the closing member is a tubular member that expands after the lifting operation by the lifting mechanism and closes a space between the first furnace body and the second furnace body.

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