JP4388859B2 - Reflow device - Google Patents

Description

  The present invention relates to a reflow apparatus.

  In an apparatus for mounting on a printed circuit board, cream solder is first printed in a predetermined pattern on the surface of the printed circuit board by a printing device using a screen mask and a squeegee. Thereafter, a chip which is an electronic component is placed, heated to melt the cream solder, and the chip is mounted on a printed board.

  FIG. 9 shows an arrangement configuration of such a mounting apparatus. A loader 100 supplies a printed circuit board (not shown). A printing apparatus 101 prints cream solder on the surface of a printed board. Reference numerals 102 and 103 denote mounters for placing chips on the cream solder printed portion of the printed circuit board. Reference numeral 104 denotes a reflow apparatus for heating and melting cream solder. An unloader 105 accommodates a processed printed board.

  By the way, when a solder bump for fixing an electronic component is formed on a printed circuit board, when reflowing the solder bump, as shown in FIG. A cavity 107 called a void is formed in 106a. In the figure, 108 is a printed circuit board, and 109 is a rewiring circuit.

  And if the cavity 107 called a void is made in this way, the conductivity will be deteriorated, causing a problem in practical use.

  In the conventional mounting apparatus, the reflow device 104 has a length L1 of 6 m or more, sometimes 9 m, and the inlet 104a and the outlet 104b are on both sides. It will be installed following 104. For this reason, this length L2 is also added. Thus, the installation space of considerable length was required with the reflow apparatus and the unloader.

  In the reflow apparatus, the heat insulation chamber is heated to a predetermined temperature in an atmosphere of nitrogen gas. Since the two ports of the inlet 104a and the outlet 104b are open, the nitrogen gas put in the inside is exposed to the outside. There is a problem that the amount of leakage is large.

  The present invention has been made in view of the above points. When a solder bump for fixing an electronic component to a printed circuit board is formed, when reflowing the solder bump, a vacuum deaeration is performed at the same time to remove bubbles in the solder bump. Therefore, voids called voids are not formed in the solder bumps, and the preheating, main heating, and cooling processes are sequentially performed in a horizontal circle so that the space required for heating can be increased. We do not provide a reflow device that can greatly reduce the amount of nitrogen gas leaked out by making the printed circuit board go in and out with only one port sharing the inlet and outlet, while greatly reducing the size. It is what.

  Therefore, the gist of the present invention is that a flat circular box-shaped base frame provided with a printed circuit board entrance / exit at one position at a height corresponding to the support frame of the post-printed circuit board transfer device on the side wall. A space for supplying and taking out, a heat insulation room for preheating, a heat insulation room for main heating, and a heat insulation room for cooling are arranged in parallel at equal intervals in a horizontal direction. These heat insulation room for preheating and heat insulation room for main heating The cooling heat insulation chamber is provided with notches in the inner wall and the side wall so that the support frame of the printed board transfer device described later can freely enter and exit, and the position where the support frame of the printed board transfer device in each interior rotates. An appropriate heating means is installed in the lower part, and a printed circuit board transfer device that is intermittently rotated in the horizontal direction with a required drive mechanism is installed in the center of the base frame.・ Take A reflow device in which a support frame that goes into each of a take-out space, a preheating heat insulation chamber, a main heat insulation chamber, and a cooling heat insulation chamber is attached radially, and is supported by the main heat insulation chamber at a predetermined timing. A reflow apparatus comprising a vacuum defoaming device for performing vacuum defoaming on a solder bump forming surface of a printed circuit board supported by a frame.

More specifically, the vacuum defoaming device having the above-described structure is established on a support frame fixed at the position of the top opening of the heat-insulating chamber for heating in the base frame and an upper horizontal plate of the support frame. a vent connected to a vacuum device, is caused to lift at a predetermined timing in an appropriate lifting means and said support frame have, with eggplant hear Redirecting a by the diameter of the printed circuit board the lower opening, the supporting frame of the upper opening with the bellows And a cylindrical vacuum chamber forming body communicated with the vent.

  Since the present invention is configured as described above, when a solder bump for fixing an electronic component to a printed circuit board is formed, when the reflow is performed, vacuum deaeration is performed at the same time to remove bubbles in the solder bump. It is possible to prevent the formation of voids called voids.

  Further, since the preheating, main heating, and cooling processes are sequentially performed in a horizontal circle, the length is not increased as in the conventional apparatus, and the installation space can be reduced. In addition, since the printed circuit board enters and exits only by one printed circuit board entrance / exit that shares the entrance and exit provided in the base frame, the amount of nitrogen gas that leaks out can be reduced as much as possible.

  In the best mode for carrying out the present invention, a flat circular box-shaped base frame provided with a printed circuit board entrance / exit at one position at a height coinciding with a support frame of a post-printed circuit board transfer device on the side wall, Space for supplying and taking out, heat insulation room for preheating, heat insulation room for main heating, heat insulation room for cooling are arranged in parallel at equal intervals in a horizontal direction. These heat insulation room for preheating, heat insulation room for main heating, The cooling heat insulation chamber is provided with notches on the inner wall and the side wall so that the support frame of the printed board transfer device described later can freely enter and exit, and from the position where the support frame of the printed board transfer device in each interior turns. In addition, an appropriate heating means is installed at the lower part, and a printed board transfer device that is intermittently rotated in the horizontal direction with a required drive mechanism is installed at the center of the base frame. Take A printed circuit board that is supported by the support frame at a predetermined timing in the heating insulation chamber, which is attached to each of the extraction space, the preheating insulation chamber, the main heating insulation chamber, and the cooling insulation chamber in a radial manner. And providing a vacuum defoaming device for performing vacuum defoaming on the solder bump forming surface.

Examples of the present invention will be described below.
1 is a partially cutaway side view of the present invention, FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1, FIG. 3 is an enlarged cross-sectional view of a vacuum degassing apparatus portion in the present invention, and FIG. FIG. 5 is a plan view of the vacuum defoaming device portion, FIG. 6 is a partially enlarged sectional view of the vacuum defoaming device during defoaming, and FIG. Sectional drawing of the state at the time of foaming, FIG. 8 is arrangement | positioning explanatory drawing in the mounting apparatus of this reflow apparatus.

  In the figure, reference numeral 1 denotes a base frame having a flat circular box shape, which is installed on the support base 2. In addition, a printed circuit board entrance 3 is provided at one position at a height that coincides with a support frame of the printed circuit board transfer device described later on the side wall of the base frame 1.

  4 is a supply / extraction space located inside the base frame 1 at a position coinciding with the entrance / exit 3 of the base frame 1, 5, 6 and 7 are preheating heat insulation chambers in which the heating temperature is sequentially increased, and 8 is heating described later A main heating heat-insulating chamber 9 is heated to a temperature at which the cream solder is melted by means, and a cooling heat-insulating chamber 9 is heated at a lower temperature than the main heat-insulating chamber 8.

  The supply / extraction space 4, the preheating heat insulation chambers 5, 6, and 7, the main heating heat insulation chamber 8, and the cooling heat insulation chamber 9 are arranged in parallel at equal intervals so as to draw a circle in the horizontal direction. These are provided with notches 10 on the inner wall and the side wall so that the support frame of the post-printing board transfer device which rotates intermittently in the horizontal direction can freely enter and exit.

  The preheating heat insulation chambers 5, 6, and 7 are each heated at a predetermined temperature with a hot plate to be described later in an atmosphere of nitrogen gas. In this embodiment, 150 ° C., 170 ° C., 190 ° C. Is set to the heating temperature. Further, the main heat insulation chamber 8 is set to a temperature of 230 ° C. at which the cream solder is melted by a heating means such as a hot plate described later. Further, the heating temperature of the cooling heat insulation chamber 9 is set to 170 ° C.

  In addition, the preheating heat insulation chambers 5, 6, 7 and the cooling heat insulation chamber 9 have heating portions that are movable in the vertical direction below the position where the support frame of the printed board transfer device described later turns. A hot plate 11 is installed.

  Reference numerals 12 and 13 denote heating means installed in the heat insulation chamber 8 for heating. One heating means 12 is installed below the position where the support frame of the printed board transfer device, which will be described later, turns so as to be vertically movable. The other heating means 13 is a heater disposed in a cylindrical vacuum chamber forming body in a vacuum degassing apparatus described later. The heater as the heating means 13 is supported by a support rod 14 suspended from an upper horizontal plate of a support frame and a circular support plate 15 fixed to the lower end of the support frame in a vacuum defoaming apparatus described later.

  Reference numeral 16 denotes a printed circuit board transfer device which is provided at the center of the base frame 1 and is intermittently rotated in the horizontal direction with a required drive mechanism. The supply / removal space 4, the preheating heat insulation chambers 5, 6, 7 and the main heating. Support frames 17, 17, 17... Entering the heat insulation chamber 8 and the cooling heat insulation chamber 9 are attached radially. The printed circuit board transfer device 16 rotates at a stroke corresponding to the distance between adjacent heat insulating chambers every 20 to 30 seconds.

  Reference numeral 18 denotes a vacuum defoaming device provided in the heat insulation chamber 8 for heating. At a predetermined timing, vacuum degassing is performed on the solder bump forming surface of the printed circuit board P supported by the support frames 17, 17, 17. It is what foams.

Further, in this embodiment, the vacuum defoaming device 18 is attached to a support frame 19 fixed to the position of the top opening 8a of the main heat insulation chamber 8 in the base frame 1 and an upper horizontal plate 19a of the support frame 19. Opened and vented at a predetermined timing in the support frame 19 with a vent 20 connected to a suitable vacuum device (not shown) and a suitable lifting means, the lower opening 21 is made to match the diameter of the printed circuit board P. Redirecting a together listening eggplant, and an upper opening 22 with a bellows 23 constructed with a cylindrical vacuum chamber forming body 24 which allowed communication with the vent 20 of the bearing frame 19.

  In the present embodiment, the elevating means is vertically movable by a cylinder 25 fixed perpendicularly to the upper horizontal plate 19a of the support frame 19 and a guide post 26 provided on the upper horizontal plate 19a of the support frame 19. The lower end is connected to the top outer edge of the cylindrical vacuum chamber forming body 24 and the upper end is connected to the piston rod 25a of the cylinder 25 via the connecting plate 27. . In addition, a packing 29 is provided on the outer edge of the lower end of the cylindrical vacuum chamber forming body 24, and a packing 30 is provided on the lower surface of the support frame 17 so as to surround the printed circuit board support.

  In the other figures, 31 is a loader, 32 is a printing device, 33 and 34 are mounters, and 35 is an unloader. The unloader 35 is arranged side by side on the side of the base frame 1 in this embodiment. Thereby, the installation space for the length of the conventional L2 can be reduced.

Next, the operation of this embodiment will be described.
The printed circuit board P is supplied into the supply / removal space 4 from the printed circuit board entrance 3 of the base frame 1 with a handler (not shown). At this time, the printed board transfer device 16 stops rotating, and the printed board P is held by the support frame 17 of the printed board transfer device. Next, the printed circuit board transfer device 16 rotates clockwise by one stroke as viewed from above, and the printed circuit board P moves to the preheating heat insulation chamber 5. And it preheats here. Then, the heat is transferred from the preheating heat insulating chamber 5 to the main heating heat insulating chamber 8 sequentially through the higher temperature preheating heat insulating chambers 6 and 7, where heating at a temperature at which the cream solder is melted is performed. And it cools in the heat insulation chamber 9 for cooling after that, and complete | finishes a series of process steps. Then, it is taken out again from the printed circuit board entrance 3 of the base frame 1 with a handler and sent to an unloader 35 arranged on the side of the base frame 1. Further, each time the printed circuit board transfer device 16 is rotated by one stroke, the printed circuit board P is addressed to / from the printed circuit board entrance / exit 3 of the base frame 1. The new printed circuit board P is inserted.

  In the main heat insulation chamber 8, the printed board P is heated from above and below by the two heating means 12 and 13, and at the same time, the vacuum degassing device 18 solders the printed board P. Vacuum defoaming is performed on the bump forming surface.

  Further, this vacuum defoaming point will be described in more detail. Until the printed board P to be processed next is sent into the heat insulation chamber 8 for heating, as shown in FIG. The vacuum chamber forming body 24 is raised. The ascending is performed by operating the cylinder 25. When the cylinder 25 is operated and the piston rod 25a extends, the cylindrical vacuum chamber forming body 24 is pulled up via the connecting plate 27 and the support rod 28. Is. Then, when the printed board P to be processed next is sent into the main heat insulation chamber 8, the cylinder 25 acts in the reverse direction as shown in FIGS. The vacuum chamber forming body 24 is lowered, and the packing 29 at the lower end thereof comes into contact with the support frame 17. And in this state, while heating, the inside air is sucked from the vent 20 of the support frame 19 by a vacuum device to perform vacuum defoaming.

It is the side view shown notched in part of the present invention. It is the sectional view on the AA line in FIG. It is an expanded sectional view of the vacuum deaerator part in the present invention. FIG. 5 is a sectional view taken along line BB in FIG. 3. It is a top view of a vacuum deaerator part. It is a partial expanded sectional view of the state at the time of defoaming of a vacuum defoaming apparatus. It is sectional drawing of the state at the time of the non-defoaming of a vacuum degassing apparatus. It is arrangement | positioning explanatory drawing in the mounting apparatus of this reflow apparatus. It is explanatory drawing of the arrangement configuration of the conventional mounting apparatus. It is sectional drawing of the solder bump in which the void was made.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base frame 3 Printed board entrance / exit 4 Supply / take-out space 5, 6, 7 Heat insulation room for preheating 8 Heat insulation room for heating 9 Heat insulation room for cooling 11 Hot plate 12, 13 Heating means in heat insulation room for heating 16 Printed circuit board Transfer device 17, 17 Support frame 18 Vacuum defoaming device 19 Support frame 20 Vent 21 Lower opening 22 Upper opening 23 Bellows 24 Cylindrical vacuum chamber forming body 25 Cylinder 28 Support rod

Claims (1)

In the flat circular box-shaped base frame provided with a printed circuit board entrance / exit at one location at a height that matches the support frame of the printed circuit board transfer device described later on the side wall, a supply / extraction space, a heat insulation chamber for preheating, a book The heat insulation chamber for heating and the heat insulation chamber for cooling are arranged in parallel at equal intervals so as to draw a circle in the horizontal direction. These heat insulation chamber for preheating, heat insulation chamber for main heating, and heat insulation chamber for cooling are described below. In addition to providing notches on the inner wall and side walls so that the support frame can freely enter and exit, appropriate heating means are installed below the position where the support frame of the printed circuit board transfer device in each interior turns, In addition, a printed circuit board transfer device that is intermittently rotated in the horizontal direction with a required drive mechanism is installed at the center of the base frame. The printed circuit board transfer device includes the supply / removal space, the preheating heat insulation chamber, the book The support frames that enter the heat insulation chamber and the cooling insulation chamber are attached in a radial pattern, and the vacuum insulation is removed from the solder bump formation surface of the printed circuit board supported by the support frame at a predetermined timing in the heat insulation chamber. A reflow apparatus comprising a vacuum defoaming apparatus for performing foaming, wherein the vacuum defoaming apparatus is fixed at a position of the top opening of the heat insulating chamber for heating in the base frame, and an upper horizontal portion of the support frame. opened to the plate, and appropriate vent connected to a vacuum device, is caused to lift at a predetermined timing in an appropriate lifting means and said support frame have, with eggplant hear Redirecting a by the diameter of the printed circuit board the lower opening, the upper opening A reflow device which is a vacuum degassing device comprising a cylindrical vacuum chamber forming body which is communicated with a vent of the support frame with a bellows.

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