JP4317463B2 - Cream solder screen printing method and apparatus - Google Patents

Description

  The present invention relates to a screen printing method and apparatus for supplying cream solder to a substrate surface in order to solder a surface mount component to a substrate or the like by, for example, a reflow heating method.

  A reflow heating method is widely known as a method for soldering surface-mounted components. Among them, as a means for supplying cream solder (hereinafter also simply referred to as solder), a metal mask is superimposed on a substrate, and then a squeegee is used. The screen printing method and apparatus for supplying solder onto the electrodes of the substrate by moving the substrate to fill the openings in the metal mask and then separating the metal mask from the substrate (hereinafter also referred to as plate separation) are known. It has been.

  In recent years, due to the high-density mounting of electronic parts and the miniaturization of electronic parts, the size of the opening of the metal mask has become finer, and the size of the opening of the metal mask is approximately three times the thickness of the metal mask. If it becomes smaller, solder may remain in the opening of the metal mask due to the plate separation operation, and the printed shape of the cream solder supplied on the electrodes of the substrate may be partially lost or not supplied.

  In addition, a flow method is widely known as a method for soldering an insertion mounted component, but there are cases in which soldering by a reflow method is adopted if the heat resistance temperature of the inserted component is high. The solder supply means used at that time is a dispenser coating method or a screen printing method. The dispenser application method is one-point application or multiple-application, and it takes time when the number of points to be applied increases. On the other hand, in the screen printing method, solder can be supplied all at once and the time can be shortened. However, the required amount of solder supply must be several times (volume ratio) that of surface mount components, and if the opening of the metal mask is enlarged, interference with the adjacent opening occurs. By increasing the thickness, the supply amount of solder can be supplemented. However, when the plate thickness of the metal mask is increased, solder tends to remain in the opening of the metal mask, resulting in a problem that printability is reduced.

  As a solution to these problems, for example, in Patent Documents 1 to 3 below, the upper surface or the lower surface of the metal mask has a confidential structure, and printing is performed by increasing or decreasing the pressure in the confidential structure during the plate separation operation. A screen printing method and apparatus for improving the detachability of the ink is disclosed.

  As shown in FIG. 5, this structure has a structure in which a pressurizing chamber 52 having an air supply / exhaust port 51 for increasing / decreasing pressure covers the entire surface of the metal mask 54 and the squeegee 55 through the metal mask frame 53. After the solder is supplied onto the substrate 57 from the opening 56 of the metal mask 54 by the squeegee 55, the squeegee 55 is released to the upper space in the pressurizing chamber 52, and then the substrate lifting device 58 is lowered to complete the process. It is something to be made.

  Patent Document 4 below discloses a structure in which a pressure head has a lower surface having a hole corresponding to an opening as an apparatus for stably printing solder at a predetermined position of a workpiece.

Further, in Patent Documents 5 and 6 below, when covering the metal mask in the pressurizing chamber, the squeegee is allowed to escape outside the pressurizing chamber, and then the local portion that covers only the periphery of the opening of the metal mask in the pressurizing chamber. A pressure structure is disclosed. As shown in FIG. 6, this structure is a local pressurization structure in which a pressurization chamber 52 ′ having an air supply / exhaust port 51 ′ for increasing and decreasing pressure covers only the periphery of the opening 56 ′ of the metal mask 54 ′. Furthermore, the point that the squeegee 55 ′ is configured to escape to the outside of the pressurizing chamber 52 ′ is different from that in FIG. In addition, the point which lowers board | substrate raising / lowering apparatus 58 'after that and complete | finishes a process is the same as that of FIG.
Japanese Patent Laid-Open No. 7-9658 Japanese Patent Laid-Open No. 9-239953 JP-A-10-51124 JP 2001-1493 A JP 2002-307653 A JP 2002-187252 A

  However, the structures disclosed in Patent Documents 1 to 3 have a structure in which the pressurizing chamber 52 covers the entire surface of the metal mask 54 and the squeegee 55. For this reason, it takes time until the pressurization volume is large and reaches a predetermined pressurization amount. Further, since the entire metal mask 54 is pressurized, the deflection of the metal mask 54 is increased as shown in FIG. 5, the adhesion between the substrate 57 and the metal mask 54 is incomplete, and the end of the metal mask 54 is There arises a problem that air leakage from the opening tends to occur.

  On the other hand, according to the method of Patent Document 4, the deflection of the metal mask can be suppressed by using the pressurizing jig that pressurizes only the opening of the metal mask, but the pressurizing jig that matches the type of the metal mask is used. The cost increases because it needs to be manufactured.

  Further, in the methods of Patent Documents 5 and 6, the squeegee 55 'is escaped to the outside of the pressurizing chamber 52', and the pressurizing volume is reduced by adopting a local pressurizing structure that pressurizes only the periphery of the opening of the metal mask 54 '. This reduces the deflection of the metal mask 54 ′ when the opening is filled with solder, and improves the adhesion between the substrate 57 ′ and the metal mask 54 ′.

  However, in the structure as shown in FIG. 6, since the residual solder 59 ′ after filling the metal mask 54 ′ is outside the pressurization chamber 52 ′, the solder is only near the opening 56 of the metal mask 54 ′. Instead, it is continuously attached to the outside of the pressurization chamber 52 '. At the time of pressurization, the solder remaining on the surface of the metal mask 54 'adheres to the outer frame of the pressurization chamber. This obstructs the confidentiality of the pressurizing chamber 52 'and makes pressure control difficult. Further, if the adhesive force of the flux is high, the metal mask 54 'is lifted together with the pressurizing chamber 52', and the metal mask 54 'may be damaged.

  Further, in the structure as shown in FIG. 6, when the substrate elevating device 58 ′ is lowered for separating the plate, the contact portion between the outer frame of the pressurizing chamber 52 ′ and the metal mask 54 ′ becomes the metal mask 54. Since it is no longer supported from the lower side, the pressurized air that should escape to the lower side of the metal mask while pushing the solder inside the opening through the opening of the metal mask is There is also a problem that leakage of the solder is deteriorated.

  The present invention has been made in view of the above-described problems of the prior art, and is a screen printing method and apparatus capable of improving the solder printability with respect to the miniaturization of the opening of the metal mask and the thickening of the metal mask. The purpose is to provide.

That is, the cream solder screen printing method of the present invention includes a mask placing step of superimposing a metal mask having an opening on the surface of the substrate, and
A solder filling step of moving the squeegee on the surface of the metal mask, filling the opening with cream solder, and leaving the unfilled cream solder at the movement end point of the squeegee;
A squeegee retracting step of retracting the squeegee away from the metal mask;
A chamber contact step of covering the moving surface of the squeegee on the metal mask and the remaining portion of the cream solder, and in a state of not including the squeegee, a pressure chamber in close contact with the metal mask;
A pressurizing step of pressurizing the inside of the pressurizing chamber;
A substrate removing step of separating the substrate from the metal mask.

  According to the method of the present invention, in the chamber contact step, the pressurization chamber is brought into close contact with not only the moving surface of the squeegee on the metal mask but also the remaining portion of the solder, so that the outer frame of the pressurization chamber is in close contact There is no solder on the metal mask at the position to be. Therefore, the adhesion between the metal mask and the pressure chamber can be maintained. In addition, the local pressure structure that covers only the moving surface of the squeegee on the metal mask and the remaining part of the solder without including the squeegee reduces the pressure area compared to the structure covering the entire surface of the metal mask. Can be suppressed. In addition, since the pressurization volume is reduced, the time required to reach a predetermined pressurization amount is short.

  In the method of the present invention, it is preferable that a solder escape groove is formed on the inner surface of the chamber so that unfilled cream solder remaining on the metal mask does not contact in the chamber contact step. According to this aspect, while preventing the residual solder from adhering to the inner surface of the pressurization chamber, the pressurization volume can be reduced and the time required to reach a predetermined pressurization amount can be shortened.

  In the method of the present invention, it is preferable that a portion other than the solder escape groove on the inner surface of the pressurizing chamber forms a surface protruding so as to be close to the metal mask. According to this aspect, the pressurization volume can be further reduced, and the time required to reach the predetermined pressurization amount can be further shortened.

  Furthermore, in the present invention, it is preferable that a receiving frame for receiving the outer frame is disposed on the back side of the metal mask at a position where the outer frame of the pressurizing chamber is in close contact with the metal mask. According to this aspect, the adhesiveness between the pressurizing chamber and the metal mask can be further improved, so that it is possible to effectively prevent air leakage from the pressurizing chamber that is likely to occur in the local pressurizing structure during pressurization.

  Furthermore, in the present invention, when the squeegee is retracted away from the metal mask, the squeegee is temporarily raised, retracted by a predetermined distance, brought into contact with the metal mask again, and then raised again to be retracted. It is preferable to make it.

  In general, when using poorly-cut (easily stretchable) solder, the solder moves on the underside of the squeegee, so if the squeegee is retracted as it is, the solder tends to drop or adhere to the mask surface or mask frame. This may impair the confidentiality of the pressurization chamber during pressurization. Therefore, when the squeegee is retracted, a so-called solder dropping operation is performed in which the squeegee is once raised, retracted several mm, and then lowered to a position where it comes into contact with the mask surface. Then, the squeegee is raised again, and then escapes to the outside of the mask frame. This prevents the solder remaining on the lower surface of the squeegee from dropping during retraction.

  Furthermore, in the present invention, in the substrate detaching step, the substrate is separated from the metal mask by a predetermined distance so as to maintain the pressurized state in the pressurized chamber, and then the inside of the pressurized chamber is moved. It is preferable to completely separate the substrate from the metal mask by reducing the pressure to atmospheric pressure.

  According to this aspect, in the first desorption, the substrate is separated from the metal mask by a predetermined distance so that the pressurized chamber can be maintained in a pressurized state. That is, at this time, the solder is still left in the opening, and there is no air escape from the opening, and by the pressurization, the solder in the opening is partially removed. Thereafter, the pressure in the pressurizing chamber is reduced, and this time, the solder is completely removed from the opening by using the adhesive force between the solder and the substrate and the restoring force of the metal mask due to the reduced pressure. In this way, by performing the substrate detachment process in two stages, it is excellent in print omission property, and further, the shape of the solder printed on the substrate is less distorted, and the solder can be prevented from being scattered. Printing can be performed.

On the other hand, the screen printing apparatus for cream solder of the present invention includes a metal mask having an opening that is superimposed on the surface of a substrate to be screen-printed,
Solder filling means for moving the squeegee on the surface of the metal mask, filling the opening with cream solder, and leaving the unfilled cream solder at the movement end point of the squeegee;
Squeegee retracting means for retracting the squeegee away from the metal mask;
A pressure chamber that covers the moving surface of the squeegee on the metal mask and the remaining portion of the cream solder, and that is in close contact with the metal mask in a state that does not include the squeegee;
Pressurizing means for pressurizing the inside of the pressurizing chamber;
A substrate removing means for separating the substrate from the metal mask,
A solder escape groove is formed on the inner surface of the pressurizing chamber so that unfilled cream solder remaining on the metal mask does not contact the inner surface of the pressurizing chamber. It has a feature that it protrudes so as to be close to the mask.

  According to the apparatus of the present invention, the pressurizing chamber is provided which covers the moving surface of the squeegee on the metal mask and the remaining portion of the solder and is in close contact with the metal mask without including the squeegee. There is no solder on the metal mask at the position where the outer frame closely contacts. Therefore, the adhesion between the metal mask and the pressurizing chamber can be maintained, and solder printing omission due to poor pressurization can be prevented.

  In addition, a local pressure structure that covers only the moving surface of the squeegee on the metal mask and the remaining portion of the solder without including the squeegee, and further, a solder escape groove is formed on the inner surface of the pressure chamber. Since the part other than the groove is formed to have a surface protruding so as to be close to the metal mask, the pressurization volume can be minimized and the predetermined pressurization amount can be reached in a short time. A screen printing apparatus having excellent productivity can be provided.

  In the apparatus of the present invention, it is preferable that the apparatus further includes a receiving frame that is disposed on the rear surface side of the metal mask at a position where the outer frame of the pressure chamber is in close contact with the metal mask. According to this aspect, the adhesiveness between the pressurization chamber and the metal mask can be further improved, so that air leakage from the pressurization chamber, which is likely to occur in the local pressurization structure during pressurization, can be effectively prevented.

  According to the present invention, there is no need for a dedicated pressurizing jig matched to the metal mask, the time required to reach a predetermined pressurizing amount is short, the deflection of the metal mask can be further suppressed, and the printing omission of cream solder Can be improved.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an embodiment of the screen printing apparatus of the present invention.

  As shown in FIG. 1, the screen printing apparatus includes a substrate 17 to be screen-printed, a metal mask 14 having an opening 16 arranged so as to overlap the surface of the substrate 17, and an opening of the metal mask 14. 16 mainly includes a pressurizing chamber 12 covering the periphery of 16, a squeegee 15 that moves on the surface of the metal mask 14, and a chamber receiving frame 20 disposed on the back side of the metal mask 14.

  The substrate 17 to be screen-printed can be placed on a vertically movable substrate lifting device 18. On the substrate 17, a metal mask 14 having a plurality of openings 16 is usually configured to overlap the surface of the substrate 17.

  As the metal mask 14, a conventionally known material made of a material such as stainless steel can be used and is not particularly limited. For example, a metal mask of an electrode for IMD (insertion mounting component) has a thickness of 0.3 to 0. A 5 mm plate is preferably used, and the size of each opening 16 is usually about 1 × 2 to 4 × 4 mm. Moreover, as a metal mask of the electrode for SMD (surface mounted components), a plate-shaped body having a thickness of 0.1 to 0.2 mm is preferably used, and the size of each opening 16 is usually 0.2 × 1. It is about ˜1 × 3 mm.

  On the surface of the metal mask 14, a squeegee 15 is provided as solder filling means for supplying solder while moving in a certain direction on the opening 16. Further, the squeegee 15 applies solder to the opening 16. After filling, the metal mask 14 is configured to be retractable.

  A pressurizing chamber 12 is disposed on the metal mask 14. An air supply / exhaust port 11 is provided above the pressurizing chamber 12 so that the internal space of the chamber can be pressurized and depressurized. Then, when the pressurizing chamber 12 is lowered, as shown in FIG. 1, the pressurizing chamber 12 and the metal mask 14 are pressurized so as to cover the moving surface of the squeegee 15 and the remaining portion of the solder and not include the squeegee 15. The outer frame 12a of the chamber 12 can be in close contact.

  Solder escape grooves 31 longer than the width of the squeegee 15 are formed on both sides of the inner surface of the pressurizing chamber 12 so that the unfilled residual solder 19 remaining on the metal mask 14 due to the movement of the squeegee 15 does not contact. . The solder escape groove 31 may be formed only on either one side.

  The size of the solder escape groove 31 can be appropriately set according to the amount of the residual solder 19 and is not particularly limited. However, the width in the moving direction of the squeegee 15 in FIG. 1 is preferably 20 to 30 mm, and the height is It is preferable that it is 15-20 mm. Thereby, it is possible to prevent the residual solder 19 and the inner surface of the pressurizing chamber 12 from contacting each other, and to minimize the internal volume in the pressurizing chamber 12.

  A portion of the inner surface of the pressurizing chamber 12 other than the solder escape groove 31 forms a protruding surface 12 b so as to be close to the metal mask 14. This further minimizes the internal volume within the pressurized chamber 12. At this time, the clearance 32 between the metal mask 14 and the protruding surface 12b is preferably 3 to 5 mm. If the clearance 32 is less than 3 mm, the applied solder and the projecting surface 12b may come into contact with each other during pressurization, which is not preferable. In addition, when the clearance 32 is increased, the internal volume in the pressurizing chamber 12 is increased, and it takes a long time for pressurization.

  A chamber receiving frame 20 is disposed on the back side of the metal mask 14 at a position where the outer frame 12 a of the pressurizing chamber 12 is in close contact with the metal mask 14. The chamber receiving frame 20 can be moved up and down independently of the substrate lifting device 18. The chamber receiving frame 20 is not limited to the same shape as the outer frame 12a as long as it can substantially receive the outer frame 12a of the pressurizing chamber 12. However, from the viewpoint of improving the adhesion, It is preferable that it is the same shape.

  Next, the screen printing method of the present invention using the above screen printing apparatus will be described with reference to FIGS.

  FIG. 2 is a process diagram showing an embodiment of the screen printing method of the present invention, in which (1) a solder filling process, (2) a chamber adhesion process and a pressurization process, (3) a substrate desorption process, (4) FIG. 3 is a flowchart showing an embodiment of the screen printing method of the present invention, and FIG. 4 is a schematic process diagram showing how to escape the squeegee in the screen printing method of the present invention. It is. Note that the flowchart in FIG. 3 is obtained by adding a process flow for pressure printing in which the upper surface of the metal mask is pressed and printed to a basic process flow in general printing in which printing is performed without pressure. .

  Hereinafter, an embodiment of the screen printing method will be described mainly with reference to the flowchart of FIG. 3, and FIGS. First, the board | substrate 17 is carried in (S1), this is set on the board | substrate raising / lowering apparatus 18, and the board | substrate 17 and the metal mask 14 are positioned (S2). Then, the chamber receiving frame 20 and the substrate lifting / lowering device 18 are individually raised to a position where they contact the lower surface of the metal mask 14 and overlap the substrate 17 and the metal mask 14 (S3, S4).

  Next, in this state, as shown in FIG. 2A, the squeegee 15 moves on the surface of the metal mask 14 in the direction of the arrow, and the opening 40 of the metal mask 14 is filled with the solder 40 and printing is performed. (S5). Then, unfilled residual solder 19 exists at the movement end point of the squeegee 15. In FIG. 2A, reference numeral 17a denotes a through hole formed in advance on the printed portion of the substrate 17.

  Then, as shown in FIG. 2B, the squeegee 15 that has been filled is retracted to a position where it does not interfere with the pressurizing chamber 12 (S6).

  FIG. 4 shows a method for retracting the squeegee 15 at this time. FIG. 4A shows a state in which the printing process of S5 is completed. In FIG. 4, the squeegee 15 moves from the left to the right along the arrow direction in the figure, and the residual solder 19 is shown in FIG. It is in the right direction inside.

  Here, in the case where the solder is well cut and difficult to stretch, as shown in FIG. 4B, after the above printing process is completed, the squeegee 15 is once raised upward along the direction of the arrow. Alternatively, it may be allowed to escape to the outside of the pressurization chamber 12 as it is.

  On the other hand, in the case of using poorly-cut (easily stretchable) solder, if the above method is used, the solder moves while the solder is attached to the lower surface of the squeegee 15, so that the solder is likely to fall during the movement. If the dropped solder is sandwiched between the pressurization chamber outer frame during pressurization, the confidentiality of the pressurization chamber 12 may be hindered.

  Therefore, in this case, as shown in FIG. 4C, after the above printing process is completed, the squeegee 15 is once lifted upward along the direction of the arrow and retracted several millimeters, and then the metal mask 14. It is preferable to lower it to a position in contact with the surface of it, and then raise it again, and then move horizontally to escape outside the pressurized chamber 12. In this way, by performing the solder dropping operation once and then squeezing the squeegee 15 to the outside of the pressurizing chamber 12, it is possible to prevent the solder from dropping while the squeegee 15 is moving.

  Following the squeegee retracting step S6, as shown in FIG. 2B, the pressurization chamber 12 is lowered to a position where it contacts the upper surface of the metal mask 14 so as to cover the moving surface of the squeegee 15 and the residual solder 19. (S7). At this time, since the residual solder 19 is accommodated in the solder escape groove 31, it does not come into contact with the pressurizing chamber 12. And a pressurization process is performed to a predetermined pressurization amount (S8). In this case, the amount of pressurization is preferably 30 to 40 kPa.

  Next, a substrate detachment process for separating the substrate 17 from the metal mask 14 is performed in two stages. That is, first, only the substrate lifting device 18 is once lowered to a position where there is no air leakage from the opening 16 of the metal mask 14 (S9). In the first detaching step S9, the substrate is separated from the metal mask by a predetermined distance so that the pressurized chamber 12 can be maintained in a pressurized state. The predetermined distance is preferably 0.5 to 1.0 mm. At this time, since the solder is still left in the opening 16 and there is no air escape from the opening, the solder can be removed from the opening partway by pressurization (FIG. 2 (3 ) State).

  Thereafter, the pressure in the pressurizing chamber 12 is reduced (S10), and this time, the solder is completely removed from the opening by using the adhesive force between the solder and the substrate 17 and the restoring force of the metal mask 14 due to the reduced pressure. This completely releases the plate. The time required for decompression at this time is preferably slower.

  Thus, by performing the substrate detachment process in two stages, while improving the print omission property, the shape of the solder printed on the substrate is less distorted, and the solder can be prevented from being scattered. Can be printed. Such a substrate detachment process. In particular, it can be suitably used as a plate separation method when using a thick metal mask of 0.5 mm or more, such as printing of electrodes for IMD (insertion mounting component).

  The substrate detachment process in the present invention is not limited to the above-described two-stage process, and the substrate 17 may be suddenly separated while being in a normal pressurized state. Is preferably 10 kPa or less, and more preferably 5 kPa or less. With such a low pressure, the solder shape does not collapse or the solder scatters.

  After the plate separation, the substrate lifting device 18 is lowered (S11), the pressurization chamber 12 is raised (S12), the chamber receiving frame 20 is lowered (S13), and finally the substrate 17 is unloaded. (S14) Screen printing is completed (state shown in FIG. 2 (4)).

  The screen printing method and apparatus of the present invention are preferably used for supplying cream solder to the surface of a substrate in order to solder a surface-mounted component or the like to the substrate or the like by, for example, a reflow heating method.

It is a schematic block diagram which shows one Embodiment of the screen printing apparatus of this invention. It is process drawing which shows one Embodiment of the screen printing method of this invention, Comprising: (1) Solder filling process, (2) Chamber adhesion process and pressurization process, (3) Substrate desorption process, (4) After completion | finish of process FIG. It is a flowchart which shows one Embodiment of the screen printing method of this invention. It is a schematic process drawing which shows how to escape the squeegee in the screen printing method of the present invention. It is a schematic block diagram which shows one Embodiment of the conventional screen printing apparatus. It is a schematic block diagram which shows other embodiment of the conventional screen printing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11: Supply / exhaust port 12: Pressurization chamber 12a: Outer frame 12b: Projection surface 14: Metal mask 15: Squeegee 16: Opening part 17: Substrate 17a: Through hole 18: Substrate raising / lowering device 19: Residual solder 20: Chamber receiving frame 31: Solder escape groove 32: Clearance 40: Solder

Claims (8)

A mask placing step of superimposing a metal mask having an opening on the surface of the substrate;
A solder filling step of moving the squeegee on the surface of the metal mask, filling the opening with cream solder, and leaving the unfilled cream solder at the movement end point of the squeegee;
A squeegee retracting step of retracting the squeegee away from the metal mask;
A chamber contact step of covering the moving surface of the squeegee on the metal mask and the remaining portion of the cream solder, and in a state of not including the squeegee, a pressure chamber in close contact with the metal mask;
A pressurizing step of pressurizing the inside of the pressurizing chamber;
A method of cream solder screen printing, comprising: a substrate detachment step of separating the substrate from the metal mask.   2. The cream solder screen according to claim 1, wherein a solder escape groove is formed on an inner surface of the pressurizing chamber so that an unfilled cream solder remaining on the metal mask does not contact in the chamber contact process. Printing method.   3. The method for screen printing of cream solder according to claim 2, wherein the portion other than the solder escape groove on the inner surface of the pressurizing chamber forms a surface protruding so as to be close to the metal mask.   A receiving frame for receiving the outer frame is disposed on the back side of the metal mask at a position where the outer frame of the pressure chamber is in close contact with the metal mask. The cream solder screen printing method described.   5. When the squeegee is retracted away from the metal mask, the squeegee is temporarily raised, retracted by a predetermined distance, brought into contact with the metal mask again, and then raised again to be retracted. The method for screen printing cream solder according to claim 1.   In the substrate detachment step, by separating the substrate from the metal mask by a predetermined distance so as to maintain the pressurized state in the pressure chamber, and then reducing the pressure chamber to atmospheric pressure, The screen printing method for cream solder according to claim 1, wherein the substrate is completely separated from the metal mask. A metal mask having an opening to be superimposed on the surface of the substrate to be screen-printed;
Solder filling means for moving the squeegee on the surface of the metal mask, filling the opening with cream solder, and leaving the unfilled cream solder at the movement end point of the squeegee;
Squeegee retracting means for retracting the squeegee away from the metal mask;
A pressure chamber that covers the moving surface of the squeegee on the metal mask and the remaining portion of the cream solder, and that is in close contact with the metal mask in a state that does not include the squeegee;
Pressurizing means for pressurizing the inside of the pressurizing chamber;
A substrate removing means for separating the substrate from the metal mask,
A solder escape groove is formed on the inner surface of the pressurizing chamber so that unfilled cream solder remaining on the metal mask does not contact the inner surface of the pressurizing chamber. A screen printing apparatus for cream solder, characterized by having a surface protruding so as to be close to a mask.   The screen printing apparatus for cream solder according to claim 7, further comprising a receiving frame disposed on a back surface side of the metal mask and in a position where an outer frame of the pressure chamber is in close contact with the metal mask.

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