JP2000021541A - Solder bump forming device and its method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form solder bumps with an uniform height on plural pads of a printed board, and to prevent the printed board from being warped or twisted, at the same time. SOLUTION: A metal mask 1 is loaded on a lower side heating plate 2 having a flat upper surface, and creamy solder 30 is filled by a squeegee in each of its plural bump forming holes 11. A printed board 100 is loaded by positioning on the metal mask 1 and an upper side heating plate 6 having a flat lower surface is loaded on the printed board 100. This device then starts heating the upper side heating plate 6 at a temperature lower than a fusing point of the creamy solder, and at the same time, it starts sandwiching the metal mask 1 and the printed board 100 between the lower side heating plate 2 and the upper side heating plate 6. After a designated time elapses, the lower side heating plate 2 is fused to the pad 101 of the printed board 100 by fusing the creamy solder 30 in a pad forming hole 11 by heating it. After this, sandwiching the metal mask 1 and the printed board is finished by cooling each part and the printed board 100 is taken out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solder bump forming apparatus and a solder bump forming method, and more particularly to a solder bump forming apparatus and a solder bump forming method for forming a solder bump on each of a plurality of pads on an insulating substrate using cream solder. Belong to the method.

[0002]

2. Description of the Related Art As electronic devices have become smaller, lighter, and more multifunctional, ball grid array (hereinafter, referred to as BGA) type packages have been used for large-scale integrated circuits mounted on a mounting substrate. Has increased. In this BGA type package, solder ball-shaped bumps (hereinafter referred to as solder bumps) are formed on each of the plurality of pads on a printed circuit board having a plurality of pads formed on one surface of an insulating substrate. As a method of forming such a solder bump, a method of printing cream solder on a pad with a predetermined thickness and performing a heat treatment, or a method of applying a flux on a pad and placing a solder ball prepared in advance on the pad, are used. There is a method of performing a heat treatment by heating, but the latter is more expensive than the former due to the need for preparing solder balls in advance or a device for supplying the solder balls onto the pads.

Hereinafter, the former method of forming solder bumps using cream solder and a solder bump forming apparatus will be described. 3 (a) to 3 (d) are partial cross-sectional side views showing a procedure for forming solder bumps for explaining a conventional solder bump forming method using cream solder.
First, as shown in FIG. 3A, a printed circuit board 100 on which a plurality of pads 101 are arranged and formed is held in a board holding section (not shown) of a solder bump forming apparatus. A metal mask 1x formed with a plurality of cream solder filling holes 12 penetrating portions of the metal plate material corresponding to the plurality of pads 101 of the printed circuit board 100, The cream solder 30 is supplied to one end of the metal mask 1x from the cream solder supply unit 3 of the solder bump forming apparatus, and the cream solder 30 is moved by the squeegee 4 of the solder bump forming apparatus as shown in FIG. While sliding on the metal mask 1x, the surface of the metal mask 1x is flush with the surface of the metal mask 1x. So as to fill the cream solder 30.

[0004] Next, as shown in FIG. 3 (c), cream solder 30 is placed on a plurality of pads 101 of a printed circuit board 100.
And leave the metal mask 1x on the printed circuit board 10
0 and heat-treated (not shown) printed circuit board 1
By melting and cooling the cream solder 30 on the plurality of pads 101 of the printed circuit board 100, the solder bumps 102x as shown in FIG.
01 respectively. Such a solder bump 10
As can be seen from the above description, the conventional solder bump forming apparatus for forming 2x includes a board holding unit for holding the printed board 100, a metal mask 1x having a plurality of cream solder filling holes 12 formed therein, and a metal mask 1x. Cream solder supply unit 3 for filling cream solder 30 into a plurality of cream solder filling holes 12 and squeegee 4, printed circuit board 10
0, a heating unit for melting the cream solder 30 on the plurality of pads 101, a cooling unit (not shown) for cooling the melted cream solder to form the solder bumps 102x, and not shown in FIG. Although not shown, a board transfer / mounting unit for transferring the printed board 100 and mounting the board on the board holding unit, which is necessary for forming the solder bumps, the metal mask 1
The configuration includes a metal mask mounting unit that mounts x on the printed circuit board 100, a control unit that controls the operation of each unit, and the like.

[0005]

In the above-described conventional solder bump forming apparatus and solder bump forming method, the metal mask 1x is placed on the printed board 100, and the cream is filled in the plurality of cream solder filling holes 12 of the metal mask 1x. After filling the solder 30, the metal mask 1x is separated from the printed circuit board 100 and subjected to a heat treatment to melt the cream solder 30 remaining on the plurality of pads of the printed circuit board 100, and then cooled to form the solder bumps 102x. When the printed circuit board 100 on which the metal mask 1x is mounted is warped or twisted, the cream solder does not have a uniform thickness and the printed circuit board 100
When the metal mask 1x is separated from the substrate, it is necessary to optimize and strictly control the material properties, device conditions, and the like, such as the adhesive index of the cream solder 30 and the separation speed of the metal mask 1x. As shown in FIGS. 4A and 4B, the cream solder 30 remains unevenly in the plurality of cream solder filling holes 12 of the metal mask 1x, and the height of the solder bumps 102x on the pad 101 varies. Therefore, there is a problem that a connection failure occurs when mounted on a mounting substrate, a problem that management of materials, devices, and the like is difficult, and a manufacturing cost is increased.
The cooling causes the printed circuit board 100 to be warped or twisted,
Similarly, there is a problem that a connection failure occurs when mounted on a mounting board.

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, it is an object of the present invention to reduce variations in height dimensions of solder bumps formed on a plurality of pads of a printed circuit board (insulating substrate) while keeping manufacturing costs low. An object of the present invention is to provide a solder bump forming apparatus and a solder bump forming method capable of suppressing a printed board from being warped or twisted and preventing connection failure when mounted on a mounting board.

[0007]

According to the present invention, there is provided a solder bump forming apparatus for forming a solder bump on each of a plurality of pads arranged on one surface of an insulating substrate. In order to achieve the above, it is characterized by having the following components that operate according to a preset procedure. (A) a first heating plate having a flat upper surface and heating the upper surface at a temperature higher than the melting point of the cream solder; (b) a plurality of pads of the insulating substrate on a metal plate having predetermined dimensions. A plurality of bump forming holes penetrating at a portion corresponding to the metal mask, the lower surface of which is mounted in close contact with the upper surface of the first heating plate. And a squeegee for filling the cream solder into each of the plurality of bump forming holes of the metal mask by sliding the solder on the metal mask and (4) the insulation before forming the solder bumps. A board mounting / transporting unit that performs alignment mounting of the board on the metal mask, removal of the insulating board from the metal mask after formation of the solder bumps, and transport of the insulating board. (E) a flat lower surface, which is mounted in close contact with the upper surface of the insulating substrate on the metal mask;
A second heating plate for heating the lower surface at a temperature lower than the melting point of the cream solder (f) a force for sandwiching the metal mask and the insulating substrate between the first heating plate and the second heating plate (G) a cooling unit that cools the first heating plate, the metal mask, the insulating substrate, and the second heating plate while applying a force to the pressing unit.

A solder bump forming method according to the present invention is a solder bump forming method for forming a solder bump on each of a plurality of pads of an insulating substrate using the solder bump forming apparatus, and includes the following steps. It is characterized by the following. (A) The cream solder supply unit and the squeegee apply cream solder to each of the plurality of bump forming holes of the metal mask mounted on the first heating plate, and the surface thereof is flush with the upper surface of the metal mask. (B) After the cream solder filling step, the substrate mounting and filling step is performed.
A board mounting for positioning the insulating substrate before solder bump formation on the metal mask such that the plurality of pads and the cream solder in the plurality of bump forming holes of the metal mask are in close contact with each other by the transfer unit. Step (c) After the substrate mounting step, mounting the second heating plate on the insulating substrate and starting heating the lower surface of the second heating plate at a temperature lower than the melting point of the cream solder. At the same time, a pre-heating / pressing start step of starting to sandwich the metal mask and the insulating substrate between the first heating plate and the second heating plate by the pressing unit. After a lapse of a preset time from the start of heating and pinching in the pressure start step, the upper surface of the first heating plate is heated at a temperature higher than the melting point of the cream solder for a preset time. The cream solder in the plurality of solder bump formation holes of the metal mask is fused to the plurality of pads of the insulating substrate, and the heating of the second heating plate continued from the preheating / pressurization start step is performed by heating the second heating plate. (E) After the cream solder fusing step, the cooling unit causes the first heating plate, the metal mask, the insulating substrate, and the After cooling the heating plate of No. 2, the cooling step of ending the sandwiching of the metal mask and the insulating substrate following the preheating / pressurizing start step (f) After the cooling step, the second heating plate A substrate removing step of removing the insulating substrate from the metal mask by the substrate mounting / transporting unit by separating the substrate from the insulating substrate.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the solder bump forming apparatus of the present invention comprises a first heating plate having a flat upper surface and heating the upper surface at a temperature higher than the melting point of cream solder. A metal plate material having a predetermined dimension is provided with a plurality of bump forming holes penetrating at portions corresponding to a plurality of pads of an insulating substrate, and a lower surface thereof is formed on an upper surface of the first heating plate. A cream that is supplied in close contact with a metal mask, and cream solder is supplied onto the metal mask, and the solder is slid over the metal mask, and the cream solder is filled in each of a plurality of bump forming holes of the metal mask. Alignment and mounting of the solder supply unit and the squeegee on the metal mask before the formation of the solder bumps, removal of the insulation substrate from the metal mask after the formation of the solder bumps, and the like A substrate mounting / transporting section for transporting the insulating substrate, and a flat lower surface. The lower surface is mounted in close contact with the upper surface of the insulating substrate on the metal mask, and the lower surface is cream soldered. A second heating plate for heating at a temperature lower than the melting point, the first heating plate and the second heating plate;
A pressurizing unit for applying a force for sandwiching the metal mask and the insulating substrate between which the heating plate is located, and the first heating plate, the metal mask, the insulating substrate, And a cooling unit that cools the second heating plate, and a control unit that controls each of the above-described units according to a preset procedure. With such a configuration, the following solder bump forming method can be performed using the solder bump forming apparatus, and the operation and effect described below can be obtained.

An embodiment of the method of forming a solder bump according to the present invention using the above-described solder bump forming apparatus is a method of forming a solder bump on the first heating plate by the cream solder supply unit and the squeegee. A cream solder filling step of filling cream solder into each of the plurality of bump forming holes of the mask so that the surface is flush with the upper surface of the metal mask, and after this cream solder filling step,
The substrate mounting / transporting unit aligns and mounts the insulating substrate before the formation of the solder bumps on the metal mask such that the plurality of pads and the cream solder of the plurality of bump forming holes of the metal mask are in close contact with each other. Substrate mounting step, and after this substrate mounting step, mounting the second heating plate on the insulating substrate and heating the lower surface of the second heating plate at a temperature lower than the melting point of the cream solder. At the same time as the start, a preheating / pressing start step of starting to sandwich the metal mask and the insulating substrate between the first heating plate and the second heating plate by the pressing unit, After a lapse of a preset time from the start of heating and sandwiching in the pressing start step, the upper surface of the first heating plate is heated at a temperature higher than the melting point of the cream solder for a preset time. Then, the cream solder in the plurality of solder bump forming holes of the metal mask is fused to the plurality of pads of the insulating substrate, and the heating of the second heating plate continued from the preheating / pressing start step is performed. And a cream solder fusing step that ends in accordance with the end of heating the first heating plate. After the cream solder fusing step, the cooling unit causes the first heating plate, the metal mask, the insulating substrate, After cooling the second heating plate, a cooling step of ending the sandwiching of the metal mask and the insulating substrate following the preheating / pressing start step, and after the cooling step,
A substrate removing step of separating the second heating plate from the insulating substrate and removing the insulating substrate from the metal mask by the substrate mounting / transporting unit.
With such a configuration, first, the thickness of the cream solder on the plurality of pads of the insulating substrate by the metal mask in the cream solder filling step can be made uniform regardless of the warpage or twist of the insulating substrate.

[0011] Further, by the preheating / pressurizing start step,
At the same time as removing the warpage and twisting of the insulating substrate before melting the cream solder, increase the degree of adhesion of the cream solder to the pad of the insulating substrate in advance to fuse the cream solder to the pad in the next cream solder fusion process. In the cream solder fusing process, the insulating substrate and the metal mask are heated while being sandwiched between the first heating plate and the second heating plate to melt the cream solder, thereby facilitating the formation of bumps. All the cream solder in the holes can be fused to the pads of the insulating substrate, the height of the solder bumps on the pads of the insulating substrate can be made uniform, and from the preheating and pressurization starting process Since the insulating substrate and the metal mask are sandwiched between the first heating plate and the second heating plate from the start until the cooling process through the cream solder fusion process, Warpage or twisting of the insulating substrate by heating and cooling can be prevented, thus, it is possible to eliminate poor connection when mounted on the mounting substrate. In addition, since there is no need for strict control on material properties, device conditions, and the like as in the conventional example, manufacturing costs can be reduced.

[0012]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing one embodiment of the solder bump forming apparatus of the present invention. The solder bump forming apparatus of this embodiment has a lower heating plate 2 having a flat upper surface and heating the upper surface at a temperature higher than the melting point of the cream solder, and a lower heating plate 2 having a predetermined size. A plurality of bump forming holes 11 penetrating at portions corresponding to the plurality of pads 101 of the printed circuit board 100 are provided in the metal plate material, and the lower surface thereof is in close contact with the upper surface of the lower heating plate 2 and A metal mask 1 mounted on a heating plate 2 and a cream for supplying cream solder on the metal mask 1 and sliding on the metal mask 1 to fill each of the plurality of bump forming holes 11 with cream solder. The solder supply unit 3 and the squeegee 4 are positioned and mounted on the metal mask 1 of the printed circuit board 100 before the formation of the solder bumps, and the printed circuit board (100) is formed from the metal mask 1 after the formation of the solder bumps. A substrate mounting / transporting unit 5 for carrying out and transporting the printed circuit board; and a flat lower surface, and the lower surface is brought into close contact with the upper surface of the printed circuit board 100 on the metal mask 1 so that the printed circuit board 100 The upper heating plate 6 of the second heating plate mounted on the upper surface and heating the lower surface at a temperature lower than the melting point of the cream solder, and the metal mask 1 having the lower heating plate 2 and the upper heating plate 6 therebetween. A pressing unit 7 for applying a force for sandwiching the printed circuit board 100, a heating control unit 8 for controlling the heating temperature, heating start, end and the like for the lower heating plate 2 and the upper heating plate 6, and a force for the pressing unit 7. The lower heating plate 2, the metal mask 1, and the printed circuit board (10
0), a cooling unit 9 for cooling the upper heating plate 6 and the like, and a control unit 10 for controlling operations of the metal masks 1 to the cooling unit 9 according to a preset procedure. Note that the heating control unit 8 may be built in the control unit 10. With such a configuration, the following solder bump forming method can be performed by using the solder bump forming apparatus, and the operation and effect described below can be obtained.

Next, using this solder bump forming apparatus,
A solder bump forming method for forming solder bumps on each of the plurality of pads 101 of the printed circuit board 100 will be described with reference to FIGS. 2 (a) to 2 (d). First, at one end of the metal mask 1 mounted on the lower heating plate 2,
The cream solder 30 is supplied from the cream solder supply unit 3,
The cream solder 30 is slid on the metal mask 1 while being moved by the squeegee 4, and the surface of the cream solder 30 is flush with the upper surface of the metal mask 1 in each of the plurality of bump forming holes 11 of the metal mask 1. (FIG. 2A, cream solder filling step).

Next, the plurality of pads 101 and the cream solder 30 in the plurality of bump forming holes 11 of the metal mask 1 are brought into close contact with each other by the board mounting / transporting section 5 of the printed board 100 before the formation of the solder bumps. Then, the upper heating plate 6 is placed on the metal mask 1 (substrate mounting step), and the upper heating plate 6 is placed on the printed board 100 so that the surfaces thereof are in close contact with each other. The heating at a temperature lower than the melting point of the cream solder on the surface is started to preheat the printed circuit board 100 and the metal mask 1 and the like, and at the same time, the lower heating plate 2 for the metal mask 1 and the printed circuit board 100 The sandwiching between the upper heating plates 6 with a preset force F is started (FIG. 2 (b), a preheating and pressurizing start step, and in FIG. 2, the lower heating plate 2 It is constant). Heating temperature of lower surface of upper heating plate 6, metal mask 1 and printed circuit board 1
00 is, for example, the printed circuit board 10
The dimensions of the solder bumps to be formed at 0, 0.13 mm in diameter and 0,0 height.
When it is 07mm and pitch is 0.25mm, it is 100 ℃ and 5kgf.

Subsequently, a predetermined time from the start of heating of the upper heating plate 6 and the start of sandwiching between the metal mask 1 and the printed circuit board 100 (time until the metal mask 1 and the printed circuit board 100 warm to near the above-mentioned heating temperature) After the lapse of time, the upper surface of the lower heating plate 2 is heated at a temperature (for example, 210 ° C.) higher than the melting point of the cream solder for a preset time (for example, 20 seconds), so that the inside of the plurality of bump forming holes 11 of the metal mask 1 is removed. Is melted and fused to the plurality of pads 101 of the printed circuit board 100, and the heating of the upper heating plate 6 is completed in accordance with the completion of the heating of the lower heating plate 2 (FIG. 2C, cream Solder fusion process).

Next, after the lower heating plate 2, the metal mask 1, the printed circuit board 100, the upper heating plate 6, and the pressing unit 7 are cooled by the cooling unit 9, the lower heating plate 2 and the upper heating plate 6 are cooled. (Cooling step), the upper heating plate 6 is separated from the printed board 100, and the board mounting / transporting section 5 is removed.
As a result, the printed board 100 is removed from the metal mask 1 (FIG. 2D, board removing step). Thus, the solder bumps 102 are formed on the respective pads 101 of the printed circuit board 100. By adopting such a process, first, when the cream solder 30 is filled in each of the plurality of bump forming holes 11 of the metal mask 1, the printed board 100 is not involved.
Even if it is warped or twisted, it can be uniformly filled regardless of these.

Even if the printed circuit board 100 is warped or twisted, it is removed before the cream solder 30 is melted by the preliminary heating and pressurizing start step, and at the same time, the cream solder 30 is After improving the adhesion to the pad 101, the solder soldering process is started while maintaining this state, so that all the cream solder 30 in the bump forming hole 11 is fused to the pad 101 of the printed circuit board 100. The height of the solder bumps 102 formed on each of the plurality of pads 101 of the printed circuit board 100 can be made uniform. In addition, the heating time of the lower heating plate 2 can be shortened by the preliminary heating.

Further, from the preheating / pressurization starting step to the cooling step, the printed circuit board 100 and the metal mask 1 are formed.
Is sandwiched between the lower heating plate 2 and the upper heating plate 6, it is possible to prevent the printed circuit board 100 from warping or twisting due to heating or cooling. Therefore,
The printed circuit board 100 after the formation of the solder bumps has no warp or twist and the solder bumps 10 on the plurality of pads 101
Since the height of 2 is also uniform, it is possible to eliminate poor connection when mounted on a mounting substrate. In addition, since strict control on material properties, device conditions, and the like as in the conventional example is not required, manufacturing costs can be reduced.

[0019]

As described above, according to the present invention, a plurality of holes for forming bumps are formed on a first heating plate having a flat upper surface at portions corresponding to a plurality of pads of an insulating substrate. Each of the plurality of bump forming holes of the metal mask is filled with cream solder by a cream solder supply unit and a squeegee so that the surface is flush with the surface of the metal mask. The insulating substrate before solder bump formation is positioned and mounted on the mask by the substrate mounting / transporting unit so that the pads and the cream solder in the bump forming holes are in close contact with each other, and are mounted on the insulating substrate. Mounting a second heating plate having a flat lower surface, starting heating this second heating plate at a temperature lower than the melting point of the cream solder, and simultaneously with the metal mask and the insulation. The plate is started to be clamped between the first heating plate and the second heating plate with a predetermined force, and after a lapse of a predetermined time from the start of the heating and the start of the clamping, the first heating plate is heated to the melting point of the cream solder. Heating at a higher temperature to melt the cream solder in the pad forming hole and fuse it to the pad of the insulating substrate; and end the heating of the second heating plate in accordance with the end of heating of the first heating plate, After that, each part is cooled to stop the sandwiching of the metal mask and the insulating substrate, and by using the device configuration and the bump forming method to take out the insulating substrate after the formation of the solder bump, the insulating substrate before the formation of the solder bump is warped or twisted. Irrespective of the condition, the cream solder can be supplied uniformly to the multiple bump forming holes of the metal mask, and the pre-heating and sandwiching before melting the cream solder insulates the cream solder in the bump forming holes in advance. In order to melt the cream solder while maintaining good adhesion between the board and the pads, all the cream solder in the bump forming holes is fused to the pads. The height can be made uniform, and the metal mask and the insulating substrate are first
Because it is sandwiched between the heating plate and the second heating plate,
It is possible to prevent the insulating substrate from being warped or twisted due to heating or cooling, and to eliminate a connection failure when the insulating substrate is mounted on the mounting substrate.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of a solder bump forming apparatus of the present invention.

FIG. 2 is a partial cross-sectional side view showing a solder bump forming procedure for explaining an embodiment of the solder bump forming method of the present invention.

FIG. 3 is a partial sectional side view showing a solder bump forming procedure for explaining a solder bump forming method using a conventional solder bump forming apparatus.

FIG. 4 is a partial cross-sectional side view for explaining a problem in a solder bump forming method using a conventional solder bump forming apparatus.

[Explanation of symbols]

 1, 1x metal mask 2 lower heating plate 3 cream solder supply unit 4 squeegee 5 board mounting / transporting unit 6 upper heating plate 7 pressurizing unit 8 heating control unit 9 cooling unit 10 control unit 11 bump forming hole 12 cream solder filling Hole 30 Cream solder 100 Printed circuit board 101 Pad 102, 102x Solder bump

Claims (2)

[Claims] 1. A solder bump forming apparatus for forming a solder bump on each of a plurality of pads arranged and formed on one surface of an insulating substrate, the apparatus having the following components operating according to a preset procedure. Characteristic solder bump forming equipment. (A) a first heating plate having a flat upper surface and heating the upper surface at a temperature higher than the melting point of the cream solder; (b) a plurality of pads of the insulating substrate on a metal plate having predetermined dimensions. A plurality of bump forming holes penetrating at a portion corresponding to the metal mask, the lower surface of which is mounted in close contact with the upper surface of the first heating plate. And a squeegee for filling the cream solder into each of the plurality of bump forming holes of the metal mask by sliding the solder on the metal mask and (4) the insulation before forming the solder bumps. A board mounting / transporting unit that performs alignment mounting of the board on the metal mask, removal of the insulating board from the metal mask after formation of the solder bumps, and transport of the insulating board. (E) a flat lower surface, which is mounted in close contact with the upper surface of the insulating substrate on the metal mask;
A second heating plate for heating the lower surface at a temperature lower than the melting point of the cream solder (f) a force for sandwiching the metal mask and the insulating substrate between the first heating plate and the second heating plate (G) a cooling unit that cools the first heating plate, the metal mask, the insulating substrate, and the second heating plate while applying a force to the pressing unit. 2. A solder bump forming method for forming a solder bump on each of a plurality of pads of an insulating substrate using the solder bump forming apparatus according to claim 1, wherein the method includes the following steps. Solder bump formation method. (A) The cream solder supply unit and the squeegee apply cream solder to each of the plurality of bump forming holes of the metal mask mounted on the first heating plate, and the surface thereof is flush with the upper surface of the metal mask. (B) After the cream solder filling step, the substrate mounting and filling step is performed.
A board mounting for positioning the insulating substrate before solder bump formation on the metal mask such that the plurality of pads and the cream solder in the plurality of bump forming holes of the metal mask are in close contact with each other by the transfer unit. Step (c) After the substrate mounting step, mounting the second heating plate on the insulating substrate and starting heating the lower surface of the second heating plate at a temperature lower than the melting point of the cream solder. At the same time, a pre-heating / pressing start step of starting to sandwich the metal mask and the insulating substrate between the first heating plate and the second heating plate by the pressing unit. After a lapse of a preset time from the start of heating and pinching in the pressure start step, the upper surface of the first heating plate is heated at a temperature higher than the melting point of the cream solder for a preset time. The cream solder in the plurality of solder bump formation holes of the metal mask is fused to the plurality of pads of the insulating substrate, and the heating of the second heating plate continued from the preheating / pressurization start step is performed by heating the second heating plate. (E) After the cream solder fusing step, the cooling unit causes the first heating plate, the metal mask, the insulating substrate, and the After cooling the heating plate of No. 2, the cooling step of ending the sandwiching of the metal mask and the insulating substrate following the preheating / pressurizing start step (f) After the cooling step, the second heating plate A substrate removing step of removing the insulating substrate from the metal mask by the substrate mounting / transporting unit by separating the substrate from the insulating substrate.