JP2014162047A - Printing method using metal mask and device for the same, and flip chip mix-loading/packaging method and device for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture, by targeting a printed wiring board for mix-loading/packaging various electronic components including flip chips, a flip chip mix-loaded/packaged printed wiring board fast, inexpensively, and stably by preventing, even in a case where the electrode pad unevenness (level difference) is great and where the pitch between connection pads is too narrow to form a solder resist therein, a wire short-circuit attributed to the effusion of a solder paste on a printing occasion and by accurately and stably transferring an optimal quantity of the solder paste necessary for the connection of the various electronic components so as to enable the packaging of the electronic components and a solder reflow.SOLUTION: A packaging device of the present invention is capable of transferring, even in the case of a printed wiring board accompanied by unevenness of electrode pad portions, a quantity of a solder paste necessary for electronic components accurately and stably onto the printed wiring board by using a metal mask mounted on a printer, and a favorable electronic component-packaged printed wiring board can be prepared by mounting, via a mounter, various electronic components including flip chips and then inducing a solder reflow.

Description

  The present invention relates to a printing method and apparatus using a metal mask for printing a solder paste on a printed circuit board for mounting various types of electronic components including flip chips on the printed circuit board, and printing the solder paste on the printed circuit board. In particular, the present invention relates to a flip chip mixed mounting method and apparatus for mounting various types of electronic components on a printed circuit board.

  Along with the high performance of electronic devices, many high-performance electronic components are mounted on a printed wiring board with high density. Therefore, in accordance with the pad shape of the electronic component, an appropriate amount of solder paste or flux is transferred and formed by a printer using a metal mask, and various electronic components are mounted at predetermined positions by a mounter, and then soldered by a reflow furnace. .

  Recently, among various electronic components, unpackaged flip chip components can be seen, and a function of a bonder is required instead of a conventional mounter. In the case of flip chip components, many solder pads are already formed, and flux may be transferred or printed instead of solder paste. Since the flux transfer is performed as a series of processes inside the mounter apparatus, more time is required for flux transfer in addition to normal electronic component mounting. As a mounter, it is important to mount components at a higher speed in order to reduce production capacity and cost, and the mounting speed is increased by separating the solder paste and flux transfer formation into a printer.

  Solder printing is used for transfer formation of solder paste that is performed prior to the mounting of electronic components on a printed wiring board.

  A printer used for this type of printing is disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-211108 (Patent Document 1) and the like, and a board recognition camera images a board recognition mark attached to a printed wiring board. While recognizing the position of the printed wiring board, a metal mask recognition camera images the recognition mark of the metal mask to recognize the position of the metal mask, aligns the printed wiring board and the metal mask, solder paste or A flux is applied on the printed wiring board. In addition, a mounting apparatus is configured by arranging a printer and a mounter or the like on which a plurality of electronic components are mounted in series, and the mounting apparatus is constructed by connecting each via a LAN. In this mounting device, the camera provided in the imaging unit of the upstream printer is positioned above the printed wiring board, and the printed wiring board, which is a multi-sided board, is imaged and recognized by the camera, and the presence or absence of a mark or the like is detected. To do. When a mark is detected, information about the detected mark is transferred to a mounter on which an electronic component, which is a downstream working device, is mounted, and used for controlling work on the mounter.

  The solder paste is made by mixing a solder alloy powder and a high-viscosity liquid flux into a cream shape, and is transferred onto a substrate through a printing mask having a predetermined opening pattern. For this printing, metal metal masks and metal squeegees excellent in mechanical strength and the like are widely used.

  The metal squeegee is applied with pressure (printing pressure) to the metal mask surface to which the solder paste is supplied on the surface with the tip thereof inclined at a predetermined attack angle (for example, 70 degrees) with respect to the metal mask surface. By sliding in the printing direction, it is used for transferring a pattern made of a solder paste onto a substrate to be printed through an opening formed in a metal mask.

  Since a semiconductor chip component or the like to be mounted can use a material having excellent insulating properties such as SiN for the insulating layer, the insulating layer can be formed even at a narrow pitch. However, the printed wiring board is made of glass epoxy (a material in which glass fibers are knitted and hardened with an epoxy material) based material, and has lower heat resistance than Si used for semiconductor chip components and the like. Therefore, an organic polyimide-based material is often used for an insulating layer used for a printed wiring board.

  On the other hand, the width of the copper wiring formed on the printed wiring board is becoming narrower as the printed wiring board has a higher density wiring. Since the resistance of the copper wiring is determined by the cross-sectional area, the thickness of the copper wiring tends to increase in order to reduce the resistance of the copper wiring. For this reason, the level difference of the copper wiring is increasing.

  The solder resist material is formed on the printed wiring board by a liquid resist coating process or a dry film resist attaching process. Therefore, large unevenness is also formed in the solder resist material due to the level difference of the copper wiring formed on the printed wiring board.

  Thus, since the printed surface of the printed wiring board has irregularities of about 20 μm to 80 μm due to the solder resist or electrode wiring applied in the previous process, a metal mask made of stainless steel with a thickness of about 100 μm is During printing, the printed wiring board is locally pushed upward by the unevenness of the printed wiring board, and a gap is formed between the metal mask and the printed wiring board. In this state, if the metal squeegee passes through the convex part of the metal mask raised by the convex part of the printed circuit board printed surface, a gap will be created between them, and solder paste will ooze out from the gap, resulting in poor printing. Cause.

  In order to prevent this, by forming an elastic film integrally on the back side of the metal mask, the gap is absorbed by the elastic film, and the adhesion between the metal mask and the printed wiring board is improved. Therefore, even if there is a step in the pad portion of the printed wiring board, the solder paste is prevented from oozing out. As a solution to this problem, Japanese Patent Application Laid-Open Publication No. 2006-1000063 (Patent Document 2) discloses that an elastic film such as silicone rubber is formed on the back side of a metal mask, and no solder balls or solder bridges are generated. In addition, it is described that the reliability of electrical connection can be improved.

  As another method for preventing this, the gap is suppressed to be small by causing the metal squeegee to perform printing while applying a large printing pressure. For this reason, conventional metal squeegees are made of special steel (super hard alloy) with excellent wear resistance to enhance its durability. As a solution to these problems, Japanese Patent Application Laid-Open No. 10-1000037 (Patent Document 3) discloses that a tapered surface is formed by etching at the tip opposite to the printing direction of the metal squeegee to facilitate elastic deformation. It is described that stable printing is possible even with a small printing pressure, and damage to the metal mask surface of the metal mask is reduced.

  As a printing defect solution due to a level difference of a printing material and a measure for reducing damage to a metal mask, a method of printing a solder paste using a resin squeegee instead of a metal squeegee has been adopted.

  As a metal mask used for printing, a metal plate is arranged in a space in the metal mask plate frame, and the metal plate is interposed between the metal plate and the metal mask plate frame through a tension mesh provided over the entire circumference. There is a combination mesh type supported by a metal mask plate frame in tension.

  By making the upper surface of the printed material face the lower surface of the metal mask and sliding the squeegee on the upper surface of the metal mask, filling the opening provided in the metal mask with the solder paste, and then separating the printed material from the metal mask. Used to transfer solder paste onto a substrate.

In the metal plate, an opening having a predetermined pattern is formed in the effective printing area by laser processing, plating, etching, or the like.
For example, in the etching method, a photoresist is applied on both sides of a metal plate, and the resist film is exposed using an exposure mask having a predetermined pattern and then etched.

JP 2000-211108 A JP 2006-1000063 A Japanese Patent Laid-Open No. 10-100430

  The solder resist formation on the printed wiring board is often formed by a photolithography process. When the connecting portions of semiconductor chip components and the like have a fine pitch, it becomes difficult to form a solder resist material having large irregularities in a fine pattern. In order to ensure insulation by the solder resist material, a thickness of 20 μm or more is required, and the ratio of the thickness (aspect ratio) to the opening diameter, which is the limit of exposure and development of the solder resist material, is 0.3. That is, when the opening diameter is 60 μm or less, the solder resist pattern cannot be formed.

  When the opening diameter of the solder resist is 60 μm or less, the solder resist material cannot be formed between the connection pads, and the copper wiring is exposed not only at the top but also at the side. Therefore, it becomes impossible to prevent the solder paste from flowing into the gaps between the copper wirings, and it is a problem to prevent the copper wiring from being bridged (short-circuited) by the solder paste.

  In addition, with the recent miniaturization of surface-mounted components, the area of the pad of the printed wiring board has been reduced, and the area of the opening of the metal mask has also been reduced accordingly.

  As described above, the squeegee disclosed in Patent Document 3, that is, a metal squeegee having a tapered surface formed by etching with respect to an opening having a small opening area, lacks the force to push the solder paste into the opening of the metal mask. Adhesion between the printed circuit board pad and the solder paste in the opening becomes insufficient. As a result, the solder paste remains in the opening of the metal mask, and the solder paste is printed (transferred) on the printed circuit board pad. ) May not be possible or there may be a problem that the amount of printed solder paste is insufficient.

The metal squeegee is considered to have caused the above-mentioned problems because the force for pushing the solder paste into the opening of the metal mask is weaker than that of the urethane rubber squeegee.
In general, the tip of the metal squeegee is required to have a high degree of flatness and flatness. However, the conventional metal squeegee described above includes the material (raw material) and the tip of the squeegee. However, there is a problem that the cost is very high. Furthermore, the tip of the squeegee is subjected to a coating treatment such as polytetrafluoroethylene widely known as Teflon (registered trademark) in order to reduce frictional resistance and perform stable printing. In addition, it is a cause of the high cost of metal squeegees.

  Furthermore, the metal mask surface of the metal mask that is subjected to sliding contact with a high printing pressure by a metal squeegee made of cemented carbide has a large damage, especially at the protrusion raised from the printed wiring board side as described above. It is remarkable. That is, there is a problem that damage on the metal mask side is large in order to perform stable printing using a conventional metal squeegee.

In general, the squeegee includes a squeegee portion and a holder attaching portion attached to the squeegee holder. The squeegee holder fixes the squeegee by attaching a holder attaching portion of the squeegee. The squeegee holder has a predetermined angle with respect to the printing surface. The attachment angle of the squeegee holder to the printer base can be adjusted to a desired angle.
When a metal mask is used, printing is completed in one direction, so that the time required for printing can be shortened compared to a mesh mask that requires a solder paste coating.
Since the metal mask does not provide a clearance (gap) between the metal mask and the substrate to be printed, a plate separation step (step of separating the metal mask and the substrate) after printing is required.

  In addition, since the solder paste is improved in fluidity when shear (shearing force) is applied, rolling reduces the viscosity and improves the fluidity. At the same time as printing using a squeegee, improving the releasability of the solder paste from the squeegee to improve the rolling property of the solder paste and to improve the printability (fillability / transferability).

  Furthermore, when the solder paste is printed using a squeegee, the solder paste rises along the side of the squeegee opposite to the metal mask, so that the metal mask is insufficiently filled with the solder paste.

  With the miniaturization of the printed material, the size of the opening formed in the metal mask has been reduced, and there is a concern that the transfer thickness of the solder paste onto the printed material may be reduced due to the size of the opening. The problem with the metal mask is that the solder paste remaining on the opening pattern portion in the metal mask after printing is reduced as much as possible, and a desired amount of the solder paste is stably transferred to the substrate.

  The present invention has been made in view of the above-described problems. Regardless of the size of the opening area of the opening of the metal mask, an appropriate amount of solder paste can be transferred and formed accurately and stably, and the connection reliability after component mounting and reflow can be improved. It is to provide a mounting apparatus that can be secured.

  In the printer, the image pickup unit is provided in the same station as the printing station that applies and prints the solder paste or flux on the printed circuit board by moving the squeegee, so the printed circuit board is imaged by the camera. However, when the presence or absence of a mark or the like is detected, the printing operation on the printed wiring board cannot be performed, the end of the presence / absence detection is waited, and printing is started after the end, so the printing is delayed and the printer There is a problem in that the tact time, which is the time required for finishing one substrate, becomes long. Further, if the takt time in the printer becomes long, the conveyance of the substrate from the printer to the downstream mounter is delayed, resulting in a problem that the total takt time as the mounting apparatus becomes long.

  In addition, if the amount of solder paste transfer required for each electronic component to be installed differs, a metal mask corresponding to that amount will be used, and printing will be repeated several times. There is a problem that the time becomes longer and the total tact time as a mounting apparatus becomes longer.

  Therefore, the present invention provides a printer process that can transfer the amount of solder paste required for various electronic components in a single printing process without lengthening the tact time. The present invention provides a printing method and apparatus using a metal mask and a flip-chip mixed mounting method and apparatus that make it possible to shorten the tact time as much as possible.

  In order to achieve the above object, in the present invention, a solder paste is printed by printing using a metal mask on the electrode pattern on a printed wiring board on which an electrode pattern for mounting an electronic component including a flip chip is formed. In a printing method using a metal mask to be transferred, an elastic emulsion is formed on the side of the metal mask facing the printed wiring board as a metal mask, and the surface of the emulsion and the opening pattern formed on the metal mask are formed. Using a metal mask with a liquid-repellent film formed on the inner wall surface, press the screen printing squeegee against the metal mask while supplying solder paste to the side opposite to the emulsion side of the metal mask. By scanning it, the elastic emulsion is copied to the surface irregularities on the printed wiring board on which the electrode pattern is formed. It was characterized by transferring the solder paste on a printed wiring plurality of electrode patterns with different magnitudes formed on the substrate in a state of being in close contact with.

  In order to achieve the above object, in the present invention, a solder paste is printed by printing using a metal mask on the electrode pattern on a printed wiring board on which an electrode pattern for mounting an electronic component including a flip chip is formed. In a printing method using a metal mask for transferring the film, an elastic emulsion is formed on the side of the metal mask facing the printed circuit board as a metal mask, and the opening formed on the surface of the emulsion and the metal mask. Using a metal mask with a liquid-repellent film formed on the inner wall surface of the pattern, and as a squeegee for printing using the metal mask, when the squeegee is in contact with the metal mask during printing, An arc-shaped concave portion is formed on the front side, and a liquid repellent film is formed on at least the surface of the arc-shaped concave portion. The size formed on the printed circuit board is different by scanning with the squeegee pressed against the metal mask with the solder paste supplied to the side opposite to the side where the emulsion of the metal mask is formed. Solder paste is transferred onto a plurality of electrode patterns.

  In order to achieve the above object, in the present invention, a solder paste is printed by printing using a metal mask on the electrode pattern on a printed wiring board on which an electrode pattern for mounting an electronic component including a flip chip is formed. In a flip chip mixed mounting method in which an electronic component including a flip chip is mounted on the transferred solder paste, an elastic emulsion is formed on the side of the metal mask facing the printed wiring board as a metal mask. The side opposite to the side where the emulsion of the metal mask is formed, using a metal mask with a liquid-repellent film formed on the surface of the emulsion and the inner wall surface of the opening pattern formed in the metal mask. With the solder paste supplied to the screen, the screen printing squeegee is pressed against the metal mask and scanned to provide elasticity. The solder paste is transferred onto a plurality of electrode patterns of different sizes formed on the printed wiring board in a state where the emulsion with the contact is made in close contact with the surface irregularities on the printed wiring board on which the electrode pattern is formed. An electronic component including a flip chip is mounted in a mixed manner on a solder paste transferred onto a plurality of electrode patterns having different sizes.

  In order to achieve the above object, in the present invention, a solder paste is printed by printing using a metal mask on the electrode pattern on a printed wiring board on which an electrode pattern for mounting an electronic component including a flip chip is formed. In a flip chip mixed mounting method in which an electronic component including a flip chip is mounted on the transferred solder paste, an elastic emulsion is formed on the side of the metal mask facing the printed wiring board as a metal mask. As a squeegee for printing using a metal mask, a metal mask in which a liquid repellent film is formed on the surface of the emulsion and the inner wall surface of the opening pattern formed in the metal mask is used during printing. When the squeegee is brought into contact with the metal mask, an arcuate concave portion is formed in front of the squeegee scanning direction. Use a squeegee with a liquid-repellent film formed on the surface of at least the arc-shaped concave part, and apply the solder paste to the opposite side of the metal mask emulsion to the metal mask. The solder paste is transferred onto a plurality of electrode patterns of different sizes formed on the printed circuit board by being pressed against the substrate, and the flip chip is transferred onto the solder paste transferred onto the plurality of electrode patterns of different sizes. It is characterized in that electronic components including are mounted together.

  Furthermore, in order to achieve the above object, in the present invention, a solder paste is printed by printing using a metal mask on the electrode pattern on a printed wiring board on which an electrode pattern for mounting an electronic component including a flip chip is formed. In a printing apparatus using a metal mask for transferring a metal mask, an elastic emulsion is formed on the side of the metal mask facing the printed wiring board, and an opening formed on the surface of the emulsion and the metal mask. A liquid-repellent film is formed on the surface of the inner wall of the pattern, and a screen printing squeegee is pressed against the metal mask while solder paste is supplied to the side opposite to the side where the emulsion of the metal mask is formed. Scanning, the elastic emulsion is brought into close contact with the surface irregularities on the printed wiring board on which the electrode pattern is formed. Characterized by transferring the state solder different plurality of electrode patterns on a printed circuit size formed on a substrate of a paste was.

  Furthermore, in order to achieve the above object, the present invention scans with a squeegee using a metal mask on the electrode pattern on the printed wiring board on which an electrode pattern for mounting an electronic component including a flip chip is formed. In a printing apparatus using a metal mask for printing solder paste, a metal mask is formed on the surface of the emulsion and the metal mask by forming an elastic emulsion on the side facing the printed wiring board. A liquid-repellent film is formed on the inner wall surface of the opening pattern, and the squeegee has an arcuate concave shape forward with respect to the scanning direction of the squeegee when the squeegee is brought into contact with the metal mask during printing. A liquid-repellent film is formed on the surface of at least the arc-shaped concave portion, and on the opposite side of the metal mask emulsion side, It by scanning the squeegee while supplying the paste is pressed against the metal mask, characterized by transferring the solder paste different plurality of electrode patterns on a size formed on a printed circuit board.

  Furthermore, in order to achieve the above object, in the present invention, soldering is performed by scanning with a squeegee using a metal mask on an electrode pattern on a printed wiring board on which an electrode pattern for mounting an electronic component including a flip chip is formed. In a flip chip mixed mounting apparatus including a printing unit that prints a paste and an electronic component mounting unit that mounts an electronic component including a flip chip on the solder paste transferred by the printing unit, the printing unit serves as a metal mask, An elastic emulsion was formed on the side of the metal mask facing the printed wiring board, and a liquid-repellent film was formed on the surface of the emulsion and the inner wall surface of the opening pattern formed in the metal mask. A squeegee is provided with a metal mask, and solder paste is supplied to the opposite side of the metal mask where the emulsion is formed. The size of the elastic emulsion formed on the printed wiring board is in close contact with the irregularities on the surface of the printed wiring board on which the electrode pattern is formed by pressing it against the tall mask and scanning. Solder paste is transferred onto a plurality of different electrode patterns, and the electronic component mounting means is mounted by mounting electronic components including flip chips on the solder paste transferred onto the plurality of electrode patterns having different sizes by the printing means. It is characterized by doing.

  Furthermore, in order to achieve the above object, in the present invention, soldering is performed by scanning with a squeegee using a metal mask on an electrode pattern on a printed wiring board on which an electrode pattern for mounting an electronic component including a flip chip is formed. A flip chip mixed mounting apparatus comprising: printing means for printing a paste; and electronic component mounting means for mounting an electronic component including a flip chip on a solder paste transferred by the printing means. An elastic emulsion is formed on the side of the metal mask facing the printed circuit board, and a liquid-repellent film is formed on the surface of the emulsion and the inner wall surface of the opening pattern formed in the metal mask. The squeegee is provided in front of the scanning direction of the squeegee when the squeegee is brought into contact with the metal mask during printing. An arc-shaped concave part is formed on the surface, and a liquid-repellent film is formed on the surface of at least the arc-shaped concave part, and solder paste is supplied to the side opposite to the side where the emulsion of the metal mask is formed In this state, by pressing the squeegee against the metal mask and scanning, the solder paste is transferred onto the plurality of electrode patterns having different sizes formed on the printed circuit board. An electronic component including a flip chip is mixedly mounted on a solder paste transferred onto the electrode pattern.

  The metal mask or squeegee used for the printer of the mounting apparatus of the present invention is not limited to the metal mask or squeegee described here.

  With the mounting device of the present invention, by using a metal mask mounted on a printer, the amount of solder paste required for electronic components can be accurately and stably obtained even on a printed wiring board having irregularities on the electrode pad portion. The printed circuit board can be transferred onto a printed circuit board, and various electronic components including flip chips can be mounted using a mounter and reflowed to produce a good mounted printed circuit board with a mixed flip chip.

It is sectional drawing of the mask and board | substrate which showed the flow of the mounting process by the flip chip mixed mounting method of Example 1. FIG. (A) is a top view of the local metal mask of the location which mounts large electronic components in the metal mask used in Example 1, (b) is XY sectional drawing of a metal mask. (A) is a top view of the local metal mask of the location which mounts a flip chip in the metal mask used in Example 1, (b) is X "-Y" sectional drawing of a metal mask. (A) is a top view of the local metal mask of the location which mounts a small electronic component in the metal mask used in Example 1, (b) is X'-Y 'sectional drawing enlarged explanatory drawing of a metal mask. It is. It is sectional drawing of the mask and board | substrate which showed the flow of the process of the flip chip mixed mounting in the case of using the conventional metal mask. It is a figure explaining the state of the flow of the paste in a squeegee front-end | tip part movement of a squeegee with respect to a mask when it prints with the squeegee mechanism of Example 1. FIG. FIG. 6 is a diagram illustrating a state of paste flow at the squeegee tip when printing is performed by the squeegee mechanism of the first embodiment. 1 is a block diagram illustrating a schematic configuration of a printer equipped with a metal mask in Embodiment 1. FIG. FIG. 3 is a flowchart showing a flow of processing for printing by a printer equipped with a metal mask in the first embodiment. It is a block diagram which shows the structure of the outline of the mounting apparatus which mounts the various electronic components in Example 2. FIG. FIG. 6 is a block diagram illustrating a schematic configuration of a printer used in Example 2 as viewed from the front. FIG. 6 is a block diagram illustrating a schematic relationship between a print head, a metal mask, and a printed board when the printer used in Example 2 is viewed from the right side. FIG. 11B is a front view of the squeegee tip portion that shows an enlarged view of the tip portion of the squeegee attached to the tip of the print head shown in FIG. 11A. FIG. 6 is a plan view showing a schematic configuration of a mounter in Embodiment 2. It is a perspective view which shows the structure of the outline of the bad mark detection apparatus integrated in the mounting apparatus of Example 2. FIG. 10 is a control block diagram of a printer and a mounter in Embodiment 2. FIG. It is a block diagram which shows the structure of the control part of the bad mark detection apparatus integrated in the mounting apparatus in Example 2. FIG. 6 is a plan view of a printed wiring board (split board) in Example 2. FIG.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

  As a metal mask used to transfer solder paste corresponding to the electrode pattern of a printed wiring board on which flip chips and various electronic components are mounted, the lower surface side of the metal mask (the side in contact with the printed wiring board) has elasticity By forming an emulsion and deforming the emulsion formed on the lower surface of the metal mask during printing, the gap between the metal mask and the printed wiring board is reduced corresponding to the unevenness of the electrodes formed on the surface of the printed wiring board. I was able to do that.

  As a metal mask, it is necessary to transfer the amount of solder paste necessary for connecting various electronic components. A large amount of solder paste is required at the place where large electronic components are mounted, but a small amount of solder paste is desirable for connecting small electronic components, and the same amount of solder paste as large electronic components In terms of amount, it is conceivable that the solder paste flows into the gap between the electronic component and the printed wiring board, causing a short circuit. Further, in a narrow pitch pad such as a flip chip, it is necessary to transfer a very small amount of the solder paste.

  Therefore, in order to transfer a small amount of solder paste necessary for connecting small electronic components, a member for controlling the solder paste dischargeability is formed in the opening of the metal mask. Also, by using a metal mask having a liquid-repellent hydrocarbon film formed on the surface of the emulsion and the exposed metal in the metal mask of the pattern portion formed at least for transferring the solder paste, The mold releasability is improved, and the solder paste can be transferred to the printed wiring board.

  Further, by forming a fluorine group at the end of the hydrocarbon film exhibiting liquid repellency as a metal mask, it is possible to further improve the releasability.

  In the following embodiments, when it is necessary for the sake of convenience, the description will be divided into a plurality of sections or embodiments. However, unless otherwise specified, they are not irrelevant to each other. There are some or all of the modifications, details, supplementary explanations, and the like.

  Further, in the following embodiments, when referring to the number of elements (including the number, numerical value, quantity, range, etc.), especially when clearly indicated and when clearly limited to a specific number in principle, etc. Except, it is not limited to the specific number, and may be more or less than the specific number.

  Components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiments, and the repetitive description thereof is omitted in principle. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  A flip-chip mixed mounting method according to the first embodiment will be described with reference to FIG. FIG. 1 is a local cross-sectional view simulating a situation in which a solder paste 9 is printed using the metal mask M11 of the first embodiment and various electronic components (C1, C2, C3) are mounted. In FIG. 1, for the sake of simplification, notations such as wiring in the printed wiring board P <b> 11 and a pad electrode surface treatment film are omitted.

  2, 3 and 4 show local enlarged views of the opening corresponding to various electronic components of the metal mask M11. FIG. 2A is a view of the opening M1 of the metal mask M11 corresponding to the large electronic component C1 as viewed from the squeegee surface (upper side), and FIG. 2B is an X− line in FIG. It is sectional drawing of the Y part. 3A is a view of the opening M2 of the metal mask M11 corresponding to the flip chip C2 as viewed from the squeegee surface (upper side), and FIG. 3B is an X′-Y of FIG. 3A. It is sectional drawing of a part. FIG. 4A is a view of the opening M3 of the metal mask M11 corresponding to the small electronic component C3 as viewed from the squeegee surface (upper side), and FIG. 4B is an X ″ line in FIG. 4A. It is sectional drawing of -Y '' part.

A conventional comparative example is shown in FIG. 5 and will be described in comparison with FIG. 1 showing the first embodiment.
As the solder paste 9 used in the verification experiment of Example 1, (A): LF-204-15 (manufactured by Tamura Chemical Co., Ltd., solder particle size: 1 to 12 μm) and (B): M705-BPS7- Printing was performed using T1J (Senju Metal Industry Co., Ltd., solder particle size: 1 to 6 μm).
In the metal mask M11, openings (M1, M2.M3) were formed at the same positions as the pads (P1, P2, P3) of the printed wiring board P11.

  The metal mask M11 of the first embodiment shown in FIG. 1 (details are FIGS. 2, 3, and 4) is formed by patterning a plating resist at a position corresponding to the opening by a photolithographic method, and metal by Ni plating. 13 was formed. In the metal mask M11 'of the comparative example shown in FIG. 5, a portion corresponding to this opening was formed by a laser processing method.

  In the metal mask M11 shown in FIG. 1, a member M5 for locally controlling the discharge amount of the solder paste 9 is formed. This member was formed by changing the plating resist pattern and performing multilayer plating. The irregularities in the opening and the burrs around the opening generated by the plating method were removed by the electropolishing method to obtain a smooth surface including the inside of the opening. The metal mask M11 'of the comparative example shown in FIG. 5 has a smooth surface including the inside of the opening by removing the irregularities in the opening and the burrs around the opening generated by the laser processing method.

  An elastic emulsion 14 was formed on the lower surface (the surface in contact with the printed wiring board P11) of the metal mask M11 shown in FIG. For the emulsion 14, there are a method of coating and drying the emulsion solution and a method of pasting the emulsion into a film. This time, in order to make the emulsion thickness uniform, we adopted a method of processing and pasting it into a film. This is the same method as attaching an etching resist film. Thereafter, a photomask having a size 10 μm larger than the size of the openings (M1, M2, M3) formed in the metal mask M11 was prepared, aligned, exposed and developed to form openings in the emulsion. As a result, an emulsion opening slightly larger than the opening of the metal mask M11 could be created. As shown in FIGS. 2, 3, and 4, the reason why the emulsion opening is made larger than the opening of the metal mask M <b> 11 is to prevent misalignment due to the emulsion forming process temperature due to the thermal expansion coefficient between the metal 13 and the emulsion 14. This is because, when the solder paste 9 is discharged from the opening of the metal mask M11, the detachability of the solder paste 9 is improved.

  The surface of the metal mask M11 was subjected to a liquid repellency treatment in order to improve the liquid repellency with the solder paste 9. As an example, a method for forming the hydrocarbon film 12 will be described.

  First, the metal mask M11 is masked to expose only the portions where the hydrocarbon film is formed. A power supply connection terminal is attached to the exposed metal part of the outer periphery of the pattern formation area of the metal mask M11, and the carbon-containing compound gas is introduced as a material gas in a film forming apparatus chamber (not shown) through the power supply connection terminal. Then, high frequency power is applied to the metal mask M11. As a result, plasma is generated in the chamber of the film forming apparatus to remove dirt existing on the surface of the metal mask M11, and then an atmospheric gas is introduced, and the hydrocarbon film 12 is formed on the surface of the metal mask M11 by plasma-assisted CVD processing. Formed.

  In this way, the liquid repellent hydrocarbon film 12 is formed on at least the surface of the solder paste transfer pattern forming portion (the exposed portion of the metal 13 and the exposed portion of the emulsion 14) including the inside of the metal mask M11 on which the solder paste transfer pattern is formed. Formed.

  The squeegee 1 was covered with a urethane resin 101 around a core material 102 made of stainless steel, and a liquid repellent film 103 was formed on the surface thereof. In addition, an arcuate concave portion 8 is formed at the tip of the squeegee 1 that is in contact with the metal mask M11. When printing, printing pressure is applied to the squeegee 1 and pressed against the metal mask surface of the metal mask M11. By operating the squeegee 1 in the printing direction 2, the solder paste 9 is opened in the metal mask M11. It can be transferred to the pad portion on the printed wiring board P11 through the portion.

  A squeegee 1 ′ shown in FIG. 5 is a flat squeegee made of a pre-urethane resin used for general printing.

  As shown in FIG. 1A or FIG. 5A, pad portions (P1, P2, P3) corresponding to various electronic components (C1, C2, C3) are formed on the printed wiring board P11. . The printed wiring board P11 is made of a glass epoxy (a material in which glass fibers are knitted and hardened with an epoxy material) based material. Further, as the printed wiring board P11 has a higher density wiring, the width of the copper wiring formed on the printed wiring board P11 is becoming narrower. Since the resistance of the copper wiring is determined by the cross-sectional area, the thickness of the copper wiring tends to increase in order to reduce the resistance of the copper wiring, and the level difference of the copper wiring is increased. Therefore, large unevenness is also formed in the solder resist P4 due to the level difference of the copper wiring formed on the printed wiring board P11. Since the printed surface of the printed wiring board P11 has irregularities of about 20 μm to 80 μm due to the solder resist P4 and electrode wiring (not shown) applied in the previous process, the metal mask M11 is made of stainless steel. During printing, the printed wiring board P11 is locally pushed upward by the unevenness, and a gap is formed between the metal mask M11 and the printed wiring board P11. In this state, when the squeegee 1 passes through the convex portion of the metal mask M11 raised by the convex portion of the printed surface of the printed wiring board P11, a gap is formed between them, and the solder paste 9 oozes out from the gap. Cause printing defects.

  The pad portion P1 on which the large electronic component C1 is mounted has no solder resist P4 formed between the pads, but the solder resist P4 is also formed on the pad portion P1 outside the pad portion P1. Yes. Therefore, the metal mask M11 is on the solder resist P4 formed on the outer periphery of the pad portion P1 when in contact with the printed wiring board P11, and the pad cannot be in contact with the metal mask M11.

  The pad portion P2 on which the flip chip C2 is mounted is not formed because the solder resist P4 cannot be resolved because of a narrow pitch between the pads. Further, a solder resist P4 is formed on the side surface of the pad portion P2 outside the pad portion P2. The height of the pad portion P2 on which the flip chip C2 is mounted is the same. However, the metal mask M11 is on the solder resist P4 formed on the outer periphery of the pad portions P1 and P3 when in contact with the printed wiring board P11, and the pad portion for the flip chip C2 is not in contact with the metal mask M11. . Since the bump pitch of the flip chip C2 is very narrow, when the solder paste 9 is formed by printing simultaneously with the large electronic component C1 or the small electronic component C3, the aspect ratio (metal mask thickness / thickness of the opening M2 formed in the metal mask M11). (Opening width) becomes very large, and it becomes very difficult to discharge the solder paste 9.

The bump diameter of the flip chip C2 used in Example 1 is φ50 μm, and the pitch between the bump centers is 80 μm. In the metal mask M11, since the emulsion 14 is formed to a thickness of 20 μm on the metal 13 having a thickness of 50 μm, the thickness of the metal mask M11 is 70 μm. The aspect ratio (metal mask thickness / opening width) of the opening M2 of the metal mask M11 is 1.4, and it is very difficult to discharge the solder paste 9 by a normal printing method. The metal mask M11 ′ of the comparative example is a metal 13 ′ having a thickness of 50 μm, and the aspect ratio (metal mask thickness / opening width) of the opening M2 ′ of the metal mask M11 ′ is 1.0. Even with this aspect ratio, it is very difficult to discharge the solder paste 9 by a normal printing method.
Generally, it is said that solder paste cannot be printed when the aspect ratio (metal mask thickness / opening width) exceeds 0.5.

  A squeegee 1 mounted on a mounting apparatus (printer) according to the present invention covers a periphery of a stainless steel core material 102 with a urethane resin 101 and forms a liquid repellent film 103 on the surface of the squeegee 1 in contact with the solder paste 9. In order to improve the discharge performance, an arcuate concave portion 8 is formed at the tip of the squeegee 1 in contact with the metal mask M11. The solder paste 9 is forcibly rolled in the arcuate concave portion 8, and the solder paste 9 is transferred to the pad portion P2 on the printed wiring board P11 through the opening M2 of the metal mask M11. Was made.

  The liquid repellent film 103 has liquid repellency on the surface of the portion in contact with the solder paste 9 near the tip of the urethane resin 101 by plasma CVD (Chemical Vaper Deposition) using a carbon compound gas. A diamond-like hydrocarbon film (diamond-like carbon film) was formed.

As another method for forming the liquid repellent film 103, a portion that comes into contact with the solder paste 9 on the surface of the squeegee 1 near the tip of the urethane resin 101 by applying an alkoxysilane-containing solution by a spray method and drying the solution. SiO ₂ having liquid repellency can be formed on the surface.

  As another method for forming the liquid repellent film 103, a copolymer (PFA) of tetrafluoroethylene and perfluoroalkoxyethylene is mixed with a urethane resin at least in a portion where the paste 9 is in contact with the squeegee 1 and sprayed. A film forming region of a copolymer (PFA) of tetrafluoroethylene and perfluoroalkoxyethylene having liquid repellency on the surface of the squeegee 1 is applied by the method and heated and cured with the same temperature profile as that of the squeegee. A film dispersed uniformly over the entire surface can be formed.

  A mechanism for transferring the solder paste 9 to the pad portion P2 on the printed wiring board P11 through the opening M2 of the metal mask M11 using the squeegee 1 will be described in detail with reference to FIGS. 6A and 6B.

  First, when the squeegee 1 is moved in the direction of the arrow 2 while pressing the squeegee 1 against the metal mask M11, the solder paste 9 is transferred from the arc-shaped concave portion 8L having the liquid repellent film 103 formed on the surface thereof to the metal mask M11. FIG. 6A (a) to (e) schematically shows a state in which the pad portion P1 on the printed wiring board P11 is filled through the pattern openings M1, M2, and M3 formed in FIG. explain.

  6A shows a state before the arc-shaped concave portion 8 having the liquid-repellent film 103 formed on the surface of the tip of the squeegee 1 reaches the opening M1 formed in the metal mask M11. Is shown. In the squeegee 1, the other corner 82 of the arc-shaped concave portion 8 is against the surface of the metal mask M11 in a state where the corner 81 of the arc-shaped concave portion 8 is pressed against the surface of the metal mask M11. The gap is vacant, and the tangential direction of the arc-shaped concave portion 8 in the vicinity of the corner portion 82 is set to a state of lowering to the right in the state of FIG. 6A. As a result, the region formed by the arc-shaped concave portion 8 and the surface of the metal mask M11 is the solder formed by the corner portion 82 of the arc-shaped concave portion 8 of the squeegee 1 and the surface of the metal mask M11. A space in which the inner space is larger than the space between the inlets (outlets) of the paste 9 and the inside is swollen is formed.

  In the state where the corner 81 of the arcuate concave portion 8 of the squeegee 1 as shown in FIG. 6A is pressed against the metal mask M11, the squeegee 1 is in the direction of the arrow 2 with respect to the metal mask M11. The solder paste 9 supplied to the front surface of the squeegee 1 in the traveling direction is pushed by the solder paste initial contact surface 104 at the tip of the squeegee 1 and moves in the same direction as the squeegee 1. A part of the paste 9 moving in the same direction as the squeegee 1 protrudes toward the metal mask M11 at the tip of the arc-shaped concave portion 8 in which the liquid-repellent film 103 is formed on the surface of the tip portion of the squeegee 1. From the gap 82 between the corner 82 and the metal mask M11 (see FIG. 6B) to enter the inside of the arcuate concave-shaped portion 8 ((a) in FIG. 6A, (B) in FIG. 6B). ~ (B)).

  The solder paste 9 that has entered the region formed by the arcuate concave portion 8 of the squeegee 1 and the metal mask M11 is a corner 81 of the arcuate concave portion 8 that is pressed against the metal mask M11. (B) in FIG. 6A and (C) in FIG. 6B). The paste 9 that has escaped upward proceeds to the gap G side along the arc-shaped concave portion 8 having the liquid-repellent film 103 formed on the surface ((d) to (e) in FIG. 6B). G is extruded toward the solder paste initial contact surface 104 side of the squeegee 1 ((a) in FIG. 6A, (g) in FIG. 6B).

  The squeegee 1 further advances in the direction of the arrow 2 so that the corner 82 at the tip of the arcuate concave portion 8 of the squeegee 1 is above the opening M1 formed in the metal mask M11 as shown in FIG. 6B. When reaching, the solder extruded from the gap G between the corner portion 82 of the arcuate concave portion 8 of the squeegee 1 and the metal mask M11 to the solder paste initial contact surface 104 side along the arrow (c). A part of the paste 9 is pushed into the opening M1 ((f) in FIG. 6B).

  The squeegee 1 further advances in the direction of the arrow 2 and the corner 82 of the arcuate concave portion 8 at the tip of the squeegee 1 passes over the opening M1 of the metal mask M11 as shown in FIG. 6A (c). When the arc-shaped concave portion 8 reaches above the opening M1, the force for pushing the solder paste 9 into the opening M1 does not act, and the arc-shaped shape of the squeegee 1 is the same as in the state of FIG. 6A (a). The paste 9 that has entered the inside of the arc-shaped concave shape portion 8 from the gap G between the corner portion 82 of the tip of the concave shape portion 8 and the metal mask M11 is a circle having a liquid-repellent film 103 formed on the surface. It is extruded from the gap G along the upper surface of the arc-shaped concave portion 8 to the solder paste initial contact surface 104 side of the squeegee 1 ((c) in FIG. 6A (c)).

  The squeegee 1 further advances in the direction of arrow 2 and the corner 81 of the arcuate concave portion 8 of the squeegee 1 pressed against the metal mask M11 as shown in FIG. 6A (d) is the opening M1 of the metal mask M11. To reach above. Here, a part of the solder paste 9 hitting the corner 81 inside the arc-shaped concave portion 8 having the liquid-repellent film 103 formed on the surface is pushed into the opening M1 of the metal mask M11. The rest escapes upward ((b) in FIG. 6A (d)) and is pushed out from the gap G along the upper surface of the arc-shaped concave portion 8 to the solder paste initial contact surface 104 side of the squeegee 1 (FIG. 6). 6A (d) (c)).

  When the squeegee 1 further advances in the direction of the arrow 2 and the corner 81 of the arcuate concave portion 8 of the squeegee 1 passes through the opening M1 of the metal mask M11 as shown in FIG. The pattern formation with the solder paste 9 on the pad portion P1 ends.

  In this way, by using the squeegee 1 in which the arc-shaped concave portion 8 is formed, the solder paste 9 is applied to the opening M1 of the metal mask M11 in the states (b) and (d) of FIG. 6A. Therefore, the solder paste 9 can be reliably filled in the opening M1.

  Here, in (b) of FIG. 6A, the solder paste 9 rolls inside the arc-shaped concave portion 8 in which the liquid-repellent film 103 is formed on the surface of the squeegee 1, and a part thereof is a metal mask M11. The state of being pushed into the opening M1 will be described in more detail with reference to FIG. 6B.

  In FIG. 6B, the change of the relative position of the solder paste 9 with respect to the squeegee 1 in the arc-shaped concave portion 8 in which the liquid repellent film 103 is formed on the surface of the tip of the squeegee 1 is indicated by arrows. In addition, (A)-(G) attached to the arrow indicating the movement of the solder paste 9 in FIG. 6B is not directly related to (A)-(E) described in FIG. 6A.

  The solder paste 9 supplied to the front of the squeegee 1 is moved forward in the direction of the arrow 2 in a state where the edge 81 at the lower end of the arcuate concave portion 8 of the squeegee 1 is pressed against the metal mask M11. From the gap G between the metal mask M11 and the end 82 opposite to the side in contact with the metal mask M11 of the arc-shaped concave portion 8 formed on the surface, the surface is repelled along the arrow (A). It enters the inside of the space formed by the arc-shaped concave portion 8 on which the liquid film 103 is formed and the metal mask M11, and proceeds in the direction of the arrow (b).

  At this time, the paste 9 already present at the position of the arrow (b) is transferred to the arc-shaped concave portion 8 along the direction of the arrow (b) by the solder paste 9 proceeding from the direction of the arrow (b). Pushed to the end 81 side. Since the end portion 81 is in contact with the metal mask M11, the solder paste 9 reaching the end portion 81 is pushed upward along the direction of the arrow (c), and then the gap G along the arrow (d). Pushed back in the direction of.

  As a result, the solder paste 9 already present at the positions of the arrows (c) and (d) is moved along the liquid repellent film 103 formed on the wall surface of the arc-shaped concave portion 8 at the position (d). Is pushed back in the opposite direction, receives a downward force along the tangential direction of the end 82L, and is pushed out in the direction of the arrow (e). The solder paste 9 pushed in the direction of the arrow (e) is pushed by receiving a further downward force at the tip of the end 82 whose tangential direction is lowered to the right in FIG. F) is pushed into the opening M1 formed in the metal mask M11, the inside of the opening M1 is filled with the solder paste 9, and is connected to the pad portion P1 on the printed wiring board P11.

  The solder paste 9 that could not enter the opening M1 is discharged from the gap G between the end portion 82 and the metal mask M11 to the paste initial contact surface 104 side of the squeegee 1 along the arrow (g). That is, the solder paste 9 that has entered the region formed by the arc-shaped concave portion 8 and the metal mask M11 is formed inside the arc-shaped concave portion 8 having a liquid-repellent film 103 formed on the surface. And is discharged to the outside of the arcuate concave portion 8 again.

  Thus, when the squeegee 1 advances in the direction of the arrow 2, the arc-shaped concave shape portion is formed from the gap G between the end portion 82 of the arc-shaped concave shape portion 8 formed in the squeegee 1 and the metal mask M11. The solder paste 9 that has entered the region formed by the metal mask M11 and the metal mask M11 rolls along the wall surface of the arc-shaped concave portion 8 having the liquid-repellent film 103 formed on the surface thereof, and ends the end portion. When the solder paste 9 is discharged to the outside of the arc-shaped concave portion 8 from the gap G between the metal mask M11 and the metal mask M11, the solder paste 9 receives a downward force, that is, a force pressed against the printed circuit board P11, and a part of the solder paste 9 is received. The solder paste 9 is reliably filled into the opening M1 by being pushed into the opening M1 formed in the above.

  The pad portion P3 on which the small electronic component C3 is mounted has a solder resist P4 formed between the pads and around the pad portion P3. Therefore, the metal mask M11 is in contact with the printed wiring board P11 and the solder resist P4 formed on the pad portion P3. In the case of the small electronic component C3, the transfer amount of the solder paste 9 is not required as much as the large electronic component C1, and a device for reducing the transfer amount of the solder paste 9 is necessary.

  1A, the metal mask M11 and the printed wiring board P11 are opposed to each other, and the openings M1, M2, and M3 formed in the metal mask M11 and the pad parts P1, P2, and P3 on the printed wiring board P11 are arranged. It is in a state of alignment. On the other hand, the same applies to the comparative example shown in FIG.

  1B, the metal mask M11 and the printed wiring board P11 are brought into contact with each other, and the solder paste 9 is applied with the squeegee 1 from the openings (M1, M2, M3) of the metal mask M11 to the pad portion ( P1, P2, P3).

  Since the squeegee 1 shown in FIG. 1B has a stainless steel core material 102, the rigidity is high and the metal mask M11 is less likely to penetrate into the opening, so that the solder paste 9 can be filled into the metal mask M11. ing. Since the squeegee 1 ′ shown in FIG. 5B is a flat squeegee, the squeegee 1 ′ is deformed by the printing pressure during printing and scrapes the solder paste 9 in the opening M <b> 1 ′ of the metal mask M <b> 11 ′.

  In FIG. 1B, the emulsion 14 formed by the metal mask M11 is deformed by the printing pressure during printing, and the metal mask M11 and the printed wiring board P11 are in close contact with each other. Therefore, no gap is generated in the outer peripheral portion of the pad portion P1 without the solder resist P4. In FIG. 5B, there is a gap between the metal mask M11 'and the printed wiring board P11, and the solder paste flows out into the gap.

  FIG. 1C shows a state where printing of the solder paste is completed and the metal mask M11 and the printed wiring board P11 are separated from each other. Since the liquid-repellent hydrocarbon film 12 is formed on the exposed portion of the metal mask M11, the solder paste 9 can be satisfactorily released.

  On the other hand, FIG. 5C of the comparative example also shows the state in which the printing of the solder paste is completed and the metal mask M11 and the printed wiring board P11 are separated, but the pad portion corresponding to various electronic components is shown. The solder paste transfer amount varied, and the solder paste 911 was formed, or the solder paste could not be transferred 912.

  In FIG. 1C, the volume of solder paste 91 corresponding to the opening M1 of the metal mask M11 was transferred to the pad portion P1 of the printed wiring board P11 on which the large electronic component C1 is mounted.

  In contrast, the pad portion P1 of the printed wiring board P11 on which the large electronic component C1 shown in FIG. 5C of the comparative example is mounted has a volume corresponding to the opening M1 ′ of the metal mask M11 ′. A small amount of solder paste 91 ′ is transferred, the solder paste 96 ′ remains in the opening M 1 ′ of the metal mask M 11 ′, and the solder paste 96 ″ turns around on the back surface of the metal mask M 11 ′ (the surface in contact with the printed wiring board P 11). Since the releasability between the metal mask M11 ′ and the solder paste 9 ′ is poor, a horn 911 is generated in the transferred solder paste 91 ′ at the pad portion P1 on the printed wiring board P11.

  The solder paste 92 was transferred from the opening M2 of the metal mask M11 to the pad part P2 of the printed wiring board P11 on which the flip chip C2 shown in FIG. However, since the aspect ratio is large, the volume corresponding to the opening M2 cannot be transferred. When the flip chip C2 is mounted, a welcome solder paste is required. However, when a large amount of the electronic component C1 is transferred as a solder paste transfer amount, the solder paste 92 is crushed when the flip chip C2 is mounted on the mounter, and adjacent to it. May cause a short circuit with the solder paste 92 on the pad. When transferring the required amount of solder for the flip chip C2 onto the printed wiring board P11 via the metal mask M11, it is necessary to control the thickness and opening size of the metal mask M11. In Example 1, since the squeegee 1 excellent in dischargeability is employed, the discharge amount of the solder paste 9 can be controlled to be reduced. Therefore, a certain amount of solder paste 94 remains in the opening M2 of the metal mask M11 for mounting the flip chip C2.

  On the other hand, the amount of solder paste 92 ′ transferred from the opening M2 ′ of the metal mask M11 ′ to the pad portion P2 is applied to the pad portion P2 ′ of the printed wiring board P11 on which the flip chip C2 of FIG. As a result, a proper solder paste 92 ′ could not be transferred. This is because, since the aspect ratio of the opening M2 ′ formed in the mask M11 ′ is large, the flat squeegee 1 ′ cannot discharge well, and the solder paste 9 cannot be transferred in a certain amount. . In the comparative example shown in FIG. 5, the flat squeegee 1 ′ in which the arcuate concave shape is not formed in the portion in contact with the metal mask M <b> 11 ′ is adopted, so that the discharge amount of the solder paste 9 can be controlled. could not. Therefore, a large amount of solder paste 94 'remains in the opening M2' of the metal mask M11 'for mounting the flip chip C2.

  The solder paste 93 was transferred from the opening M3 of the metal mask M11 to the pad portion P3 of the printed wiring board P11 on which the small electronic component C3 shown in FIG. When the small electronic component C3 is mounted, the amount of the solder paste 93 transferred to the pad portion P3 needs to be smaller than that of the large electronic component C1. This is because if the transfer amount of the solder paste is large, similar to the transfer amount of the large electronic component C1 to the pad portion P1, the solder paste 93 is crushed when the mounter mounts the small electronic component C3 on the pad portion P3. The solder paste may flow out between the pad portions P3 and may be short-circuited. In order to transfer an appropriate amount of solder paste 93 to the pad portion P3 corresponding to the small electronic component C3, a member M5 is formed inside the opening C3 of the metal mask M11 to control the transfer amount of the solder paste 93. There is a need. In Example 1, since the squeegee 1 excellent in dischargeability is employed, the discharge amount of the solder paste 9 can be controlled to be reduced. Therefore, a certain amount of solder paste 95 remains in the opening M3 of the metal mask M11 for mounting the small electronic component C3.

  On the other hand, in the pad portion P3 ′ of the printed wiring board P11 on which the small electronic component C3 of FIG. 5C, which is a comparative example, is mounted, as in the case of the large electronic component C1, the opening portion of the metal mask M11 ′. Solder paste 93 'was transferred from M3'. When mounting the small electronic component C3, it is necessary to make the amount of the solder paste 93 'transferred to the pad portion P3 smaller than in the case of the pad portion P1 mounting the large electronic component C1, but the solder paste 9 As a transfer amount of ', the transfer was carried out in a large amount as in the case of the pad portion P1 on which the large electronic component C1 is mounted. Further, since the releasability between the metal mask M11 ′ and the solder paste 9 ′ is poor, the solder paste 95 ′ remains unevenly in the opening M3 ′ of the metal mask M11 ′ as in the large electronic component C1. . Since the releasability between the metal mask M11 'and the solder paste 9' is poor, the horn 931 is generated in the transferred solder paste 93 'at the pad portion P3 on the printed wiring board P11.

  (D) of FIG. 1 is a figure which shows the state which mounted various electronic components with the mounter. Since an appropriate amount of the solder paste 9 can be transferred to the pad portions P1 to P3 corresponding to the mounting positions of the various electronic components, the various electronic components can be mounted satisfactorily.

  On the other hand, FIG. 5D of the comparative example is also a diagram showing a state in which various electronic components are mounted by the mounter. Since an appropriate amount of the solder paste 9 cannot be transferred to the pad portions P1 to P3 corresponding to the mounting positions of various electronic components, the various electronic components cannot be mounted satisfactorily.

  (E) of FIG. 1 is the printed wiring board P13 after heat-processing the printed wiring board P12 which mounted various electronic components in the reflow furnace of the nitrogen atmosphere which optimized the heat processing profile. Various electronic components were able to connect well with the printed wiring board P11.

  On the other hand, FIG. 5E of the comparative example is a printed wiring board P13 ′ after heat treatment is performed on the printed wiring board P12 on which various electronic components are mounted in a reflow furnace in a nitrogen atmosphere in which the heat treatment profile is optimized. . At the place where the large electronic component C1 is mounted, there is a place where a short circuit is locally generated by the solder paste transferred excessively. Moreover, in the flip chip C2 mounting part, the disconnection for the solder paste not being transferred, and the short circuit of the part where many were transferred were seen. Further, at the place where the small electronic component C3 is mounted, the solder paste flows into the gap between the printed wiring board P11 and the small electronic component C3 due to the excessively transferred solder paste, causing a short circuit. As described above, various electronic components are not well connected to the printed wiring board P11.

Therefore, in the conventional construction method, it is necessary to use a metal mask corresponding to various electronic components and repeat printing a plurality of times. Therefore, the manufacturing tact is long and there is a problem in productivity.
Moreover, in some printed wiring boards, the solder paste may be printed again after reflow, and printing with higher difficulty is required.

  The configuration of the printer P1 equipped with the metal mask 11 according to the first embodiment will be described with reference to FIG. FIG. 7 is a front view of the printer P1 equipped with the metal mask M11 of the first embodiment. In FIG. 7, for the sake of simplification, the display of the frame, side wall, column, support member, and the like of the apparatus is omitted.

  The printer P1 includes a metal mask unit 110, a substrate support table unit 23, a pair of squeegee units 120L and 120R, a squeegee drive mechanism unit 130, and a control unit 21.

  The metal mask portion 110 is in a tensioned state by a metal mask 11 provided with a pattern opening formed corresponding to a desired circuit pattern of a substrate (for example, a printed wiring board) 6 and a tension mesh surrounding the metal mask 11. A plate frame 22 having a rectangular shape in a plan view and a support member 111 that supports the plate frame. The substrate support table unit 23 includes a table 231 on which the substrate 6 is placed, a chuck unit 232 that fixes the substrate 6 placed on the table 231, and a vertical drive unit 233 that drives the table 231 up and down. . The squeegee unit 120L includes a squeegee 1L, a squeegee holder 3L, a squeegee holder fixing jig 16L, and a squeegee head 15L air cylinder 24L. Similarly, the squeegee portion 120R includes a squeegee 1R, a squeegee holder 3R, a squeegee holder fixing jig 16R, a squeegee head 15R, and an air cylinder 24R. The air cylinders 24L and 24R are fixed to the support member 25, and drive the squeegee portion 120L and the squeegee portion 120R connected to the air cylinders 24L and 24R, respectively, up and down. The support member 25 is supported by bearings 26L and 26R engaged with the drive shaft 27. The drive shaft 27 is constituted by a ball screw, and when it is rotationally driven by the motor 30, the bearing portions 26L and 26R engaged with the drive shaft 27 move in the left-right direction in the drawing, and the squeegee portion 120L and the squeegee portion 120R. Moves along the guide shaft 28 in the horizontal direction in the figure. The drive shaft 27 and the guide shaft 28 are supported by a pair of left and right fixing plates 29L and 29R.

  The control unit 21 controls the operation of each unit of the printer P1. First, the air cylinder drive unit 31 that drives the pair of air cylinders 24L and 24R is controlled by a control signal from the control unit 21 to drive the pair of air cylinders 24L and 24R, respectively. Further, the control unit 21 controls the driver unit 32 of the motor 30 to rotate the motor 30 in the forward and reverse directions. Further, the chuck drive unit 34 that drives the chuck unit 232 of the substrate support table unit 23 is controlled by the control signal from the control unit 21 to open and close the chuck unit 232 that fixes the substrate 6 placed on the table 231. Let the action take place. Furthermore, the table drive unit 33 that drives the vertical drive unit 233 of the substrate support table unit 23 is controlled by a control signal from the control unit 21 to move the table 231 up and down. Furthermore, the chuck 232 is opened and closed by controlling the drive unit 34 of the chuck 232 of the substrate support table unit 23 according to a control signal from the control unit 21.

The operation of the printer having the above configuration will be described with reference to the flowchart of FIG.
First, the substrate 6 is conveyed by a conveying means (not shown) and placed on the substrate support table 23 (S201), and the substrate 6 is fixed and held on the substrate support table 23 by the chuck portion 232. . Next, the table driving unit 32 drives the vertical driving unit 233 to raise the table 231 (S202), and the substrate 6 is brought into close contact with the metal mask 11 of the metal mask unit 110. Next, the air cylinder 24L is driven by the air cylinder drive unit 31 to lower the squeegee head 15L (S203), and the squeegee 1L is brought into close contact with the metal mask 11 (S204). At this time, the pair of squeegee portions 120L and 120R are located at the left end portion of FIG.

  Next, in this state, the solder paste is supplied to the vicinity of the squeegee 1L by a solder paste supply means (not shown) (S205). When the solder paste is supplied, the driver unit 32 is controlled to drive the motor 30, and the drive shaft 27 formed of a ball screw is rotated so that a pair of squeegee units 120L and 120R and a squeegee 1L attached to the tip thereof. The pattern of the metal mask 11 by the solder paste is printed on the printed material 6 by moving from the left side to the right side of FIG. 3 along the metal mask 11 in a state of pressing the metal mask 11 (S206). After the squeegee 1L has moved a predetermined distance, the driver unit 32 stops driving the motor 30 and stops the movement of the squeegee 1L.

  Next, the air cylinder drive unit 31 drives the air cylinder 24L to raise the squeegee head 15L (S207), and the squeegee 1L is pulled away from the metal mask 11. Next, the table drive unit 33 controls the vertical drive unit 233 to lower the table 231 (S208), and the substrate 6 held by the chuck unit 232 is peeled off from the metal mask 11. When the table 231 reaches the descending end, the processing of the table 231 by the vertical drive unit 233 is stopped, the chuck drive unit 34 is controlled to open the chuck unit 232 holding the substrate 6 and handling means (not shown) Thus, the substrate 6 is removed from the table 231 (S209). It is determined whether or not the substrate thus taken out is the last substrate to be processed (S210). In the last case, the processing is terminated.

  On the other hand, if there is a substrate to be processed next, the processing flow from S201 is executed again. In this case, however, the squeegee head 15R is lowered in S203, and the squeegee 1L is replaced with 1R in S204, S206, and S207. Further, printing is performed by moving the squeegee 1R in close contact with the metal mask 11 from the right side to the left side in FIG. As described above, the solder paste supplied by printing using the squeegees 1L and 1R alternately is always in front of the traveling direction of the squeegee in close contact with the metal mask. It can be used effectively.

  In this way, by mounting the metal mask M11 of the first embodiment on a printer and printing using the squeegees 1L and 1R, a single printing process is performed regardless of the size of the opening area of the opening of the metal mask M11. Thus, the solder paste 9 can be accurately and stably transferred to the printed wiring board P11.

  Various printed circuit boards P12 are prepared by mounting various electronic components on the printed circuit board P11 ′ to which the solder paste 9 has been transferred in this way by a mounter (not shown), and the printed circuit board P12 mounted with the flip chip and the various electronic components is mounted. By applying heat treatment in a reflow furnace in a nitrogen atmosphere, it is possible to produce a printed wiring board P13 on which various electronic components are mounted with high precision by solder connection.

  Using an area array bump type flip chip mounting chip and a printed wiring board, we verified the misalignment of solder printing. As for the metal mask used for the solder printing method, the opening was formed by the metal mask in which the opening was formed by the electroforming method (plating process) according to this example and the laser processing method described in the comparative example described in FIG. The difference in printability between the two metal masks was verified.

  As described with reference to FIGS. 1 and 5, a step of about 5 μm is formed on the surface of the printed wiring board for flip chip mounting by the copper wiring immediately below the solder resist. For this reason, it is considered that the metal mask alone has a step between the metal mask and the printed wiring board, and is not sufficiently adhered. For this reason, a positional shift of about 10 μm locally occurred, and a solder paste was not sufficiently filled in the solder resist opening, and a portion where the electrode pad portion was exposed was observed. This is presumably because the liquid repellent ADC treatment was applied to the entire exposed surface of the metal mask, so that the friction between the squeegee and the metal mask was reduced.

  In addition, this printed wiring board has electrode pads surrounded by solder resist, so the solder paste stayed on the solder resist. However, in the case of electrode bumps corresponding to narrow pitch, there is no solder resist between the electrode pads. It seems that it may cause a defect.

  On the other hand, in a metal mask with an emulsion formed on the side of a metal printed circuit board produced by electroforming, the flexible emulsion is deformed by the pressure applied to the squeegee during solder printing, and the surface of the printed circuit board is deformed. Even if there is a step, the metal mask and the printed wiring board can be in close contact with each other. Moreover, since the metal mask produced by the electroforming method forms a plating resist with photolithography, an opening pattern can be formed with high accuracy. Therefore, it is considered that the solder paste is sufficiently filled in all the solder resist openings of the area array bump type flip chip mounting printed wiring board. Compared to a metal mask manufactured by laser processing, a metal mask manufactured by electroforming is considered to be more effective for a printed wiring board for flip chip mounting with a narrow pitch.

  Next, a process of heat-treating the printed circuit board P12 in a reflow furnace in a nitrogen atmosphere after mounting the flip chip and various electronic components on the printed circuit board P12 will be described. In the process of heat-treating the printed circuit board P12 mounted with various electronic components in a reflow furnace in a nitrogen atmosphere, the flip chip and various electronic components are melted by the molten solder in the nitrogen reflow process (low oxygen concentration of less than 75 ppm) of the nitrogen reflow furnace. The printed wiring board on which the flip chip and various electronic components are mounted is subjected to ultrasonic cleaning, filled with underfill, and thermally cured.

  During the reflow process, when the solder melts, the solder is attracted to the electrode pad, and the solder is formed so as to cover the entire surface of the electrode pad portion. When an appropriate amount of solder is present between the flip chip and the printed wiring board, the solder existing between the flip chip side pad and the printed wiring board side pad serves to attract the pads. Can fulfill. This phenomenon is called self-alignment. When an appropriate amount of solder is present between the mounted flip chip or various electronic components and the printed wiring board, the mounting accuracy of the flip chip or various electronic components is better than the mounting accuracy of the mounter. When the amount of solder is small, it is not possible to attract the electrode pads on the flip chip or various electronic components side and the electrode pads on the printed wiring board side, and the position where the flip chip and various electronic components are mounted on the printed wiring board by the mounter Therefore, the flip chip mounting position accuracy is the mounting accuracy of the mounter. Also, if the amount of solder is excessively large, the solder between the pads may be fused to each other, causing a short circuit, and the solder is attracted to the pad position, making the flip chip mounting position unstable. there is a possibility. Similarly, if there is no short circuit between the electrode pads due to the outflow of the solder paste between the electrode pads during printing of the solder paste, even a slight misalignment of the printing position of the solder paste is acceptable.

  The conventional flux transfer method needs to perform flux transfer in the mounter, and it is considered that there is a limit in improving the throughput. In order to improve the throughput, it is considered effective to separate the functions by the line configuration of the printer and the mounter by printing the flux or using the welcome solder printing method. In the following, as a second embodiment, a configuration in which functions are separated by a line configuration of a printer for transferring flux and a mounter on which electronic components such as flip chips are mounted will be described.

  The solder paste 9 was transferred to the printed wiring board P11 in the same manner as in Example 1 to produce a printed wiring board P13 on which various electronic components were mounted. The configuration of the metal mask M11, the squeegee 1, etc. is the same as that described in the first embodiment.

  Hereinafter, specific embodiments using the mounting apparatus of the present invention will be described with reference to the drawings. 9 shows a partially omitted electronic component mounting apparatus J1, FIG. 10 is a front view of the main part (printing station) of the printer, FIG. 11A is a right side view of the main part of the printer, and FIG. 11B is the front end of the squeegee J33B. FIG. 12 is a plan view of a mounter for mounting electronic components, FIG. 13 is a perspective view of a printer mark detection station, FIG. 14 is a control block diagram of the printer and mounter, and FIG. 15 is a printer bad mark detection. A block diagram of the device is shown.

  First, in FIG. 9, the electronic component mounting apparatus J1 according to the embodiment of the present invention forms a pattern hole for printing on the printed wiring board P, that is, on the land, by moving the solder paste or flux on the metal mask. A printer J2 to be applied, and mounters J3 and J4 for mounting electronic components on the printed wiring board via the solder paste or flux, each connected by a LAN J101, for example.

  As shown in FIG. 10, the printing station J201 of the printer J2 includes a substrate support table J12 installed on a base J11, a metal mask support means J13 disposed above the substrate support table J12, and a substrate support table. A first image pickup means J14 for picking up an image of a board recognition mark KM placed diagonally on a printed wiring board P disposed between J12 and the metal mask support means J13 and supported by the board support table J12; and a metal mask support A second image pickup means J15 for picking up an image of a metal mask recognition mark placed on the metal mask S disposed above the means J13 and supported by the metal mask support means J13; and a pair of print heads disposed above the metal mask S. J16A, J16B (see FIG. 11A) and substrate P are supplied onto substrate support table J12 Supply conveyor J17, a discharge conveyor J18 for discharging the substrate P from the substrate support table J12, and a monitor J47 (see FIG. 14) to be described later for displaying images picked up by the first and second image pickup means J14 and J15. ing.

  The substrate support table J12 has a first movement mechanism J21 for moving in the direction of the X axis (see FIG. 10) extending in the horizontal direction, and a rotation for rotating in the horizontal plane provided on the first movement mechanism J21. A mechanism J22, a second moving mechanism J23 provided on the rotating mechanism J22 for moving in the direction of the Z-axis extending in the vertical direction, a substrate support plate J24 provided on the second moving mechanism J23, A transport mechanism (not shown) is provided on the upper surface of the substrate support plate J24 to transport the substrate P in the X-axis direction.

  The metal mask support means J13 is a metal mask support frame J25 that supports the peripheral edge of the lower surface of the metal mask S, and is disposed above the metal mask support frame J25 and presses the metal mask S against the metal mask support frame J25. A pair of cylinders J26 and a moving mechanism J27 for moving in the direction of the Y axis extending in the horizontal direction are provided.

  The first imaging means J14 includes a substrate recognition camera J28, a moving mechanism J29 that moves the substrate recognition camera J28 in the X-axis and Y-axis directions, and an illumination device that irradiates light onto the substrate P on the substrate support table J12 (see FIG. Not shown). The second imaging means 15 includes a metal mask recognition camera J31, a moving mechanism J32 that moves the camera J31 in the X-axis direction, and an illumination device that irradiates light onto the substrate P on the substrate support table J12 (not shown). The camera 31 is moved in the Y-axis direction by the moving mechanism J34 of the print heads 16A and 16B.

  As shown in FIG. 11A, the print heads J16A and J16B are arranged at intervals in the Y-axis direction, and squeegees J33A and J33B are attached to the lower end portions, respectively, and are simultaneously moved in the Y-axis direction by the moving mechanism J34. While moving, the vertical movement mechanisms J35A and J35B individually move in the Z-axis direction. When the print heads J16A and J16B move to the left in FIG. 11A, the right print head J16A descends and the squeegee J33A slides on the metal mask S and moves to the right in FIG. 11A. The left print head J16B descends and the squeegee J33B slides on the metal mask S. Therefore, two printing processes are performed by one reciprocating movement of the print heads J16A and J16B. Here, the attachment of the squeegee J33A and the squeegee J33B to the print heads J16A and J16B may be attached in an inverted C shape as shown in FIG. 7 described in the first embodiment.

  FIG. 11B is an enlarged view of the tip portion of the squeegee J33B. On the side of the tip of the squeegee J33B that is in contact with the metal mask S, an arcuate recess 8 ′ is formed in the same manner as described in the first embodiment with reference to FIGS. 6A and 6B. One end 81 ′ of the arcuate recess 8 ′ is in contact with the mask, and the other end 82 ′ is formed so as to form a gap G between the mask S as described with reference to FIG. 6B. Are attached to the print head J16B. Further, as described in the first embodiment, a liquid repellent film 103 ′ is formed in a portion that comes into contact with the solder paste including the arc-shaped recess 8 ′.

  The supply conveyor J17 is connected to the substrate support table J12 by moving the substrate support table J12 in the left direction of FIG. 10, and when the supply conveyor J17 is driven in this state, the conveyance mechanism of the substrate support table J12 is interlocked. ing. Further, the discharge conveyor J18 is connected to the substrate support table J12 by moving the substrate support table J12 in the right direction of FIG. 10, and when the discharge conveyor J18 is driven in this state, the transport mechanism of the substrate support table J12 is interlocked. It has become.

  Further, the downstream side of the supply conveyor J17 extends to a mark detection station (hereinafter referred to as a detection station) J102 located on the upstream side of the printing station J201.

  Hereinafter, the mark detection device J103 provided in the detection station J102 will be described with reference to FIGS. J104 is a mark sensor, and is movably provided by a Y-axis drive motor J106 described later along a beam J105 extending in the Y-axis direction. The mark sensor J104 is, for example, a reflection type sensor, which emits light downward from an LED serving as a light emitting unit, receives light returned by reflection, and detects a mark based on the amount of light received. Further, the beam J105 is provided so as to be movable in the X-axis direction by an X-axis drive motor J111 described later along a beam drive axis J107 extending in the X-axis direction.

  Next, a description will be given based on the plan view of the mounter J3 in FIG. 12. A component supply unit that supplies various electronic components one by one to the component take-out portion (component suction position) on the base J52 of the mounter J3. A plurality of J53s are arranged side by side. A supply conveyor J54, a positioning portion J55, and a discharge conveyor J56 are provided between the opposing component supply units J53 group.

  J58A and J58B are a pair of beams that are long in the X direction. The screw shaft J60 is rotated by driving the Y-axis motor J59, respectively, and the component suction and extraction of the printed wiring board P and the component supply unit J53 along the pair of left and right guides J61. The position is moved individually in the Y direction. Each of the beams J58A and J58B is provided with mounting heads J57A and J57B that move along a guide (not shown) by an X-axis motor J62 (see FIG. 14) in the longitudinal direction, that is, the X direction. Each mounting head J57A or J57B is equipped with two vertical axis motors J63 for moving the two suction nozzles J67 up and down, and two θ-axis motors J64 for rotating around the vertical axis. ing. Accordingly, the suction nozzles J67 of the two mounting heads J57A and J57B can move in the X direction and the Y direction, can rotate around the vertical line, and can move up and down.

  J66 is a component recognition camera that images the electronic component sucked and held by the suction nozzle J67. J68 is a board recognition camera that images the board recognition mark KM, which is a positioning mark attached to the printed wiring board P.

  Next, a control block diagram of the printer J2 and the mounter J4 in FIG. 14 will be described. First, the printer 2 will be described. J43 is a CPU (Central Processing Unit) as an overall control device, and J44 is a RAM (Random Access Memory) as a storage device in which various information is stored. Then, based on various information related to the printing operation and mark detection stored in the RAM: J44, the printing operation and mark detection operation stored in a ROM (Read Only Memory) J45 as a storage device. Printing operation and mark detection are performed in accordance with the operation program.

  J46 is an interface to which a monitor J47, a touch panel switch J48, a drive circuit J49, a recognition processing device J50, a mark detection device J103, and the like are connected. The monitor J47 is provided with various touch panel switches J48, and an operator can perform various settings related to printing and mark detection by operating the touch panel switch J48.

  The Y-axis drive motor J106 of the mark detection device J103 is connected to an interface J46 via a mark sensor Y-axis drive motor driver (hereinafter referred to as a Y-axis drive driver) J110. The X-axis drive motor J111 is connected to the interface J46 via a mark sensor X-axis drive motor driver (hereinafter referred to as X-axis drive driver) J112.

  Next, the mounter J4 will be described. Each element of the mounter J4 is centrally controlled by a CPU (Central Processing Unit) J71, and a ROM (Read Only Memory) J72 for storing a program related to this control. A RAM (Random Access Memory) J73 for storing various data is connected. Further, a monitor J75 for displaying an operation screen and the like and a touch panel switch J76 as input means formed on the display screen of the monitor J75 are connected to the CPU J71 via an interface J77. In addition, a pair of front and rear beams J58A and J58B that are long in the X direction are moved in the Y direction. An X axis motor J62, a vertical axis motor J63 for moving the suction nozzle J67 up and down, a θ axis motor J64 for rotating the suction nozzle J67 around the vertical axis, etc. are connected to the CPU J71 via a drive circuit J78 and an interface J77. Has been.

  The RAM: J73 stores mounting data for each type of printed wiring board P related to component mounting, and mounting of each electronic component in the printed wiring board P is performed for each mounting order (step number). The X direction, Y direction and angle information of coordinates, the arrangement number information of each component supply unit that supplies electronic components, and the like are stored. The RAM: J73 stores information on the type of each electronic component corresponding to the component supply unit arrangement number of each component supply unit, that is, component arrangement data, and further, shape data, recognition data, and control data. -Parts library data consisting of parts supply data is stored.

J79 is a recognition processing device connected to the CPU: J71 via an interface J77. An electronic component picked up and held by the suction nozzle J67 is recognized by the component recognition camera J66, or printed circuit board P is printed. The recognition processing device J79 recognizes an image obtained by picking up the substrate recognition mark KM attached to the substrate recognition camera J68 and sends the processing result to the CPU J71. That is, the CPU: J71 recognizes an instruction so as to perform recognition processing (such as calculation of a displacement amount) on an image captured by the component recognition camera J66 and recognition processing of an image captured by the board recognition camera 68. In addition to outputting to J79, the recognition processing result is received from the recognition processing device J79.
The interface J77 is connected to the interface J46 of the printer J2 via the LAN: J101.

  Next, the operation of the printer J2 when printing on the printed wiring board P, which is a split board (multi-sided board) having a plurality of regions where independent circuits are formed, will be described. First, when the printed wiring board P is placed on the supply conveyor J17 at the detection station J102, a photo sensor (not shown) detects this, and a board stopper (not shown) descends, while the board P is being conveyed. Hold it so that it does not move.

  In the detection station J102, a drive signal is output from the CPU: J43 to the X-axis drive driver J112, the X-axis drive motor J111 is driven, and the beam J105 moves in the X-axis direction. Is output to the Y-axis drive driver J110, the Y-axis drive motor J106 is driven, the mark sensor J104 moves along the beam J105, and the divided substrate is divided for each divided substrate region (hereinafter referred to as a divided substrate portion) J124. A mark J123 (see FIG. 16) indicating a defect attached to the part is detected.

  As described above, the mark on the printed wiring board is detected by the mark sensor J104 at the detection station J102 located upstream thereof before being applied at the printing station J201. Information about the mark can be prevented from being sent to the downstream mounter.

  When the mark sensor J104 detects the mark J123, information on the detected mark J123, that is, information such as the number of the divided board portion J124 to which the mark is attached, the number of the printed wiring board P, and the like is sent via the interface J46. The data is sent to the CPU: J43, and further sent from the CPU: J43 to the RAM: J44 for storage. When the detection operation for all the divided board portions J124 of the printed wiring board P is completed, the board support table J12 moves to the left in FIG. 10 and is connected to the supply conveyor J17.

  Then, the supply conveyor J17 is driven, the substrate P is transferred onto the substrate support table 12 in conjunction with the transfer mechanism of the substrate support table J12, and the supply conveyor J17 stops when it reaches a predetermined position. Then, after the substrate P is positioned on the substrate support table 12 by a positioning mechanism (not shown), the substrate support table J12 moves rightward to the initial position (hereinafter referred to as “origin position”). Return.

  Next, the board recognition camera J28 of the first imaging means J14 moves in the X-axis direction and the Y-axis direction to pick up two board recognition marks KM at positions on the diagonal of the printed wiring board P, and the image is recognized. Recognition processing is performed by the processing device J50. Then, the CPU: J43 obtains the position coordinates of the substrate recognition mark KM from the recognition processing result of the recognition processing device J50, and stores this position information in the RAM: J44 (see FIG. 14).

  Further, the metal mask recognition camera J31 of the second imaging means J15 moves in the X-axis direction and the Y-axis direction to pick up two metal mask recognition marks on the metal mask S, and the image is recognized by the recognition processing device J50. It is processed. Then, the CPU J43 obtains the position coordinates of the metal mask recognition mark SM from the recognition processing result of the recognition processing device J50, and stores this position information in the RAM: J44. Then, the CPU: J43 compares the position of each substrate recognition mark KM stored in the RAM: J44 with the position of each metal mask recognition mark SM to position the substrate P and the metal mask S relatively. The amount of deviation is calculated and stored in RAM: J44. The amount of deviation is Δx1 in one X direction and Δy1 in the Y direction, Δx2 in the other X direction, and Δy2 in the Y direction.

  Therefore, based on this amount of deviation, the CPU: J43 drives the moving mechanism J21 of the substrate support table J12, the rotating mechanism J22, and the moving mechanism J27 of the metal mask support means J13 via the drive circuit J49, and the printed circuit board P The relative position shift of the metal mask S is corrected for positioning.

  Next, one of the print heads J16A, J16B, for example, the right print head J16A is lowered by the vertical movement mechanism J35A, the squeegee J33A is moved in the Y-axis direction by the movement mechanism J34, and the squeegee J33A is placed on the metal mask S. The solder paste, which is a solder paste or flux, is applied onto the lands of the printed wiring board P through the printing pattern holes provided in the metal mask S.

  When the printer 2 stores the positional deviation amount in the RAM: J44, the printer 2 transmits the positional deviation amount to the mounter J4. Therefore, the CPU J71 of the mounter J4 stores the received positional deviation amount. .

  Therefore, when the mounter J4 mounts an electronic component on the printed wiring board P, the mounter J4 takes into account the received displacement amount.

As described above, when the solder paste is applied on the land of the printed wiring board P at the printing station J201 of the printer J2, the next printed wiring board P is supplied to the supply conveyor J17 at the detection station J102 in parallel with the application operation. As in the above detection operation, the mark sensor J104 moves along the beam J105 and detects the mark J123 indicating the defect attached to the divided substrate portion for each divided substrate portion J124. (See FIG. 16).
When the mark is detected, information on the mark J123 is stored in the RAM: J44.

  Thereafter, similarly, in the detection station J102, the detection operation of the mark J123 is performed for each divided substrate portion J124 in parallel with the application operation on the printed wiring board P in the printing station J201. The influence of the mark detection operation on the operation can be reduced as much as possible. As a result, the delay of the application operation can be avoided and the tact time in the printer J1 can be shortened as much as possible.

  Moreover, the printed wiring board P for which the coating operation has been completed is sent to the carry-out conveyor J18. Further, when the CPU: J43 outputs a conveyance signal to the carry-out conveyor 18, at the same time, the CPU: J46 transmits the information of the mark J123 to the mounter J4 via the interface J46 and the LAN: J112.

  As a result, the mounter J4 receives the mark information related to the printed wiring board P at the same time as the printed wiring board P is conveyed from the printer J1. And CPU: J71 which received the information of mark J123 stores it in RAM: J73.

Hereinafter, the mounting operation of the electronic component on the printed wiring board P that is the split board will be described.
When the printed wiring board P is inherited from the upstream printer J1 to the mounter J3 and exists on the supply conveyor J54, the printed wiring board P on the supply conveyor J54 is moved to the positioning portion J55 and fixed. The mounting data stored in the RAM: J73, that is, the XY coordinate position to be mounted on the printed wiring board P, the rotation angle position around the vertical axis, the FDR number (arrangement number of each component supply unit J53), etc. are designated. In accordance with the information about the bad mark transmitted from the upstream printer J1 and stored in the RAM J73, the electronic component to be mounted is taken out from the predetermined component supply unit J53 by the suction nozzle J67, and Mounting on the printed wiring board P is performed.

  That is, the Y-axis motor J59 is driven in the Y direction to move the beam J58A or J58B along the pair of guides J61, and the X-axis motor J62 is driven in the X direction to suck the suction nozzle J67 of the corresponding mounting head J57A or J57B. The electronic component to be mounted is moved above a predetermined component supply unit J53, the vertical axis motor J63 is driven, the suction nozzle J67 is lowered, and the electronic component is sucked and taken out.

  Further, the electronic component held by suction is imaged (fly imaging) while the suction nozzle J67 is moved above the component recognition camera J66, and recognition processing is performed by the recognition processing device J79, and the beam J58A or J58B is moved above the printed wiring board P. The board recognition mark KM moved and imaged on the printed wiring board P is imaged and recognized by the recognition processor J79 (similar to FIG. 14).

  Then, the CPU J71 adds (adds) the above-described positional deviation amounts Δx1, Δy1, Δx2, and Δy2 to the coordinates of the respective substrate recognition marks KM that are recognized by the recognition processing device J79. Get the coordinates.

  Furthermore, the CPU: J71 uses the coordinates of the obtained pseudo screen recognition marks instead of the substrate recognition marks KM as a reference to actually convert the electronic data from the mounting coordinates of each electronic component of the mounting data stored in the RAM: J73. Find the coordinates for mounting the part. That is, the mounting coordinates at the center of the pair of solder pastes corresponding to the electronic components, which are positions where the electronic components are to be mounted, are grasped. Then, in addition to the mounting coordinates of the printed wiring board P obtained in this way, the positional displacement amount of each electronic component sucked and held by the suction nozzle J67 recognized by the recognition processing device J79 is taken into account, and the suction of each mounting head is taken into account. The electronic component sucked and held by the nozzle J67 is mounted.

  As described above, when the electronic component is mounted on the printed wiring board P, the CPU: J77 is transmitted from the upstream printer J1 and follows the information about the bad mark stored in the RAM: J73. The Y-axis motor J59 and the like are controlled so that electronic components are not mounted on the split board portion J124 with the bad mark. As a result, the bad mark detection operation at the mounter J3 can be omitted, and the tact time at the mounter J3 can be shortened as much as possible. Furthermore, as described above, the influence of the bad mark detection on the application operation of the printer J1 can be minimized, the delay of the application operation can be avoided, and the bad mark detection operation and the application operation from the printer J1 are completed. Since the printed wiring board P can be carried out to the downstream mounter J3 without delay, the manufacturing time of the printed wiring board P in the mounting apparatus in which the printer J1 and the mounter J3 are combined can be further shortened.

  The electronic components are repeatedly taken out, recognized, and mounted until all the electronic components to be mounted on one printed wiring board P are completed. When all the electronic components are completed, the printed wiring board P is transferred from the positioning unit 55 to the discharge conveyor 56. , And the production of the first printed wiring board P related to the electronic component mounting is completed, and the production of the second printed wiring board P is performed.

  The printed wiring board P conveyed to the discharge conveyor J56 is conveyed from the discharge conveyor J56 to the supply conveyor J54 of the downstream mounter J4. Then, simultaneously with the start of the conveyance of the printed wiring board P to the supply conveyor J54, bad mark information about the printed wiring board P that has started the conveyance is transmitted from the mounter J3 to the mounter J4. In the mounter J4, the transmitted bad mark information is stored in the RAM similarly to the mounter J3, and when mounting the electronic component on the corresponding printed wiring board P, various electronic components are mounted based on the bad mark information. The

  As described above, since the bad mark information about the split board portion J124 with the bad mark is transmitted from the mounter J3 to the mounter J4, the bad mark detection operation at the mounter J4 can be omitted, and the tact time at the mounter J3 can be reduced. It can be as short as possible.

  Although the embodiments of the present invention have been described above, various alternatives, modifications, and variations can be made by those skilled in the art based on the above description, and the present invention is not limited to the various embodiments described above without departing from the spirit of the present invention. It encompasses alternatives, modifications or variations.

  DESCRIPTION OF SYMBOLS 1 ... Squeegee 1 '... Flat squeegee 3 ... Squeegee holder 6 ... To-be-printed object 8 ... Arc-shaped concave-shaped part 9 and 9' ... Solder paste M11, M11 '... Metal mask P11 ... Printed wiring board 12 ... Hydrocarbon Film 13, 13 '... Metal 14 ... Emulsion 21 ... Control panel 22 ... Plate frame 23 ... Substrate support table section 100 ... Printer 101 ... Urethane resin 102 ... Core material 103 ... Liquid repellent film 110 ... Metal mask section 120L, R ... Squeegee unit 130 ... Squeegee drive mechanism unit J1 ... Electronic component mounting device J2 ... Printer J3, J4 ... Mounter J43 ... CPU J68 ... Substrate recognition camera J71 ... CPU J102 ... Mark detection station J103 ... Mark detection device J104 ... Mark sensorJ123 ... Mark J124 ... Split board area (split board section) J201 ... Printing station

Claims (15)

  A method of transferring a solder paste by printing using a metal mask on the electrode pattern on a printed wiring board on which an electrode pattern for mounting an electronic component including a flip chip is formed, and as the metal mask, An elastic emulsion is formed on the side of the metal mask facing the printed wiring board, and a liquid repellent film is formed on the surface of the emulsion and the inner wall surface of the opening pattern formed in the metal mask. The elasticity of the metal mask is measured by pressing a screen printing squeegee against the metal mask while scanning with the solder paste supplied to the side of the metal mask opposite to the side on which the emulsion is formed. In a state in which an emulsion having an adhesive is closely adhered to follow the surface irregularities on the printed wiring board on which the electrode pattern is formed, Printing method using a metal mask, which comprises transferring the solder paste different plurality of electrode patterns on the sizes formed line on the substrate.   A method of transferring a solder paste by printing using a metal mask on the electrode pattern on a printed wiring board on which an electrode pattern for mounting an electronic component including a flip chip is formed, and as the metal mask, An elastic emulsion is formed on the side of the metal mask facing the printed wiring board, and a liquid repellent film is formed on the surface of the emulsion and the inner wall surface of the opening pattern formed in the metal mask. As a squeegee for printing using the metal mask, an arcuate concave portion is formed forward with respect to the scanning direction of the squeegee when the squeegee is brought into contact with the metal mask during the printing. The milk mask of the metal mask is formed using a squeegee having a liquid repellent film formed on the surface of at least the arc-shaped concave portion. The squeegee is pressed against the metal mask and scanned with the solder paste supplied to the side opposite to the side on which the solder paste is formed, thereby forming a plurality of electrode patterns with different sizes formed on the printed circuit board. A printing method using a metal mask, wherein the solder paste is transferred.   3. A printing method using the metal mask according to claim 1, wherein a member for controlling a solder paste discharge property is formed in an opening of the metal mask, and the size formed on the printed board. A metal mask characterized by transferring an amount of solder paste necessary for connection of each electronic component including the flip chip onto a plurality of electrode patterns having different sizes through a member for controlling the solder paste dischargeability. Was the printing method.   3. A printing method using the metal mask according to claim 1, wherein a metal mask characterized by forming a liquid-repellent hydrocarbon film as the liquid-repellent film is used. Printing method.   A solder paste is transferred by printing using a metal mask on the electrode pattern on a printed wiring board on which an electrode pattern for mounting an electronic component including a flip chip is formed, and the flip chip is placed on the transferred solder paste. An elastic emulsion is formed on the side of the metal mask facing the printed circuit board as the metal mask, and formed on the surface of the emulsion and the metal mask. For screen printing using a metal mask having a liquid repellent film formed on the inner wall surface of the opening pattern and supplying a solder paste to the side of the metal mask opposite to the side on which the emulsion is formed The electrode pattern was formed on the elastic emulsion by pressing the squeegee against the metal mask and scanning. Transfer solder paste onto a plurality of electrode patterns of different sizes formed on the printed circuit board in close contact with the surface irregularities on the lint wiring substrate, and a plurality of electrodes of different sizes A flip-chip mixed mounting method, wherein electronic components including flip chips are mixedly mounted on a solder paste transferred onto a pattern.   A solder paste is transferred by printing using a metal mask on the electrode pattern on a printed wiring board on which an electrode pattern for mounting an electronic component including a flip chip is formed, and the flip chip is placed on the transferred solder paste. An elastic emulsion is formed on the side of the metal mask facing the printed circuit board as the metal mask, and formed on the surface of the emulsion and the metal mask. When a metal mask having a liquid-repellent film formed on the inner wall surface of the opening pattern is used, and the squeegee is brought into contact with the metal mask during printing as the squeegee for printing using the metal mask An arc-shaped concave portion is formed forward in the scanning direction of the squeegee, and at least the surface of the arc-shaped concave portion Using a squeegee on which a liquid-repellent film is formed, and pressing the squeegee against the metal mask in a state where the solder paste is supplied to the side opposite to the side on which the emulsion is formed, and scanning. By transferring solder paste onto a plurality of electrode patterns of different sizes formed on the printed circuit board, and electronic components including flip chips on the solder paste transferred onto the plurality of electrode patterns of different sizes A flip-chip mixed mounting method characterized by mounting in a mixed manner.   7. The flip-chip mixed mounting method according to claim 5 or 6, wherein a member for controlling a solder paste discharge property is formed in the opening of the metal mask, and the sizes formed on the printed circuit board are different. A flip-chip mixed mounting method, wherein an amount of solder paste necessary for connection of each electronic component including the flip chip is transferred onto a plurality of electrode patterns via a member for controlling the solder paste dischargeability.   A printing apparatus for transferring a solder paste by printing using a metal mask on the electrode pattern on a printed wiring board on which an electrode pattern for mounting an electronic component including a flip chip is formed. An elastic emulsion is formed on the side of the metal mask facing the printed wiring board, and a liquid repellent film is formed on the surface of the emulsion and the inner wall surface of the opening pattern formed in the metal mask. The elastic property is obtained by pressing a screen printing squeegee against the metal mask while scanning with the solder paste supplied to the side of the metal mask opposite to the side on which the emulsion is formed. The emulsion is formed on the printed wiring board in a state where the emulsion is brought into close contact with the surface irregularities on the printed wiring board on which the electrode pattern is formed. Printing apparatus using a metal mask, characterized in that transferring the magnitude of different electrode patterns on the solder paste.   A printing apparatus for printing a solder paste by scanning with a squeegee using a metal mask on the electrode pattern on a printed wiring board on which an electrode pattern for mounting an electronic component including a flip chip is formed. An elastic emulsion is formed on the side of the metal mask facing the printed wiring board, and a liquid repellent film is formed on the surface of the emulsion and the inner wall surface of the opening pattern formed in the metal mask. The squeegee is formed with an arcuate concave portion in front of the scanning direction of the squeegee when the squeegee is brought into contact with the metal mask during the printing, and at least the arcuate shape is formed. A state in which a liquid-repellent film is formed on the surface of the concave portion and the solder paste is supplied to the side of the metal mask opposite to the side on which the emulsion is formed A printing apparatus using a metal mask, wherein a solder paste is transferred onto a plurality of electrode patterns having different sizes formed on the printed circuit board by scanning the squeegee against the metal mask. .   A printing apparatus using the metal mask according to claim 8 or 9, wherein a member for controlling a solder paste discharge property is formed in an opening of the metal mask, and the size formed on the printed board. A metal mask characterized by transferring an amount of solder paste necessary for connection of each electronic component including the flip chip onto a plurality of electrode patterns having different sizes through a member for controlling the solder paste dischargeability. Was a printing device.   A printing apparatus using the metal mask according to claim 8 or 9, wherein a hydrocarbon film showing liquid repellency is formed as the liquid repellency film. Printing device.   Printing means for printing a solder paste by scanning with a squeegee using a metal mask on the electrode pattern on a printed wiring board on which an electrode pattern for mounting electronic components including flip chips is formed, and transfer by the printing means An electronic component mounting means for mounting an electronic component including a flip chip on the solder paste, the printing means serving as the metal mask on the side facing the printed wiring board of the metal mask. Comprises a metal mask in which an elastic emulsion is formed and a liquid repellent film is formed on the surface of the emulsion and the inner wall surface of the opening pattern formed in the metal mask, and the emulsion of the metal mask By scanning the squeegee against the metal mask while supplying the solder paste to the side opposite to the side where the metal is formed On the plurality of electrode patterns of different sizes formed on the printed wiring board in a state where the elastic emulsion is brought into close contact with the surface irregularities on the printed wiring board on which the electrode pattern is formed. Solder paste is transferred, and the electronic component mounting means mounts the electronic components including flip chips mixedly mounted on the solder paste transferred onto the plurality of electrode patterns having different sizes by the printing means. Flip chip mixed mounting device.   Printing means for printing a solder paste by scanning with a squeegee using a metal mask on the electrode pattern on a printed wiring board on which an electrode pattern for mounting electronic components including flip chips is formed, and transfer by the printing means An electronic component mounting means for mounting an electronic component including a flip chip on the solder paste, the printing means serving as the metal mask on the side facing the printed wiring board of the metal mask. Comprises a metal mask in which an elastic emulsion is formed and a liquid-repellent film is formed on the surface of the emulsion and the inner wall surface of the opening pattern formed in the metal mask, and the squeegee includes the printing Sometimes when the squeegee is brought into contact with the metal mask, an arcuate concave portion is formed in front of the scanning direction of the squeegee, A liquid-repellent film is formed at least on the surface of the arc-shaped concave portion, and the squeegee is placed in a state where the solder paste is supplied to the side of the metal mask opposite to the side where the emulsion is formed. A solder paste is transferred onto a plurality of electrode patterns of different sizes formed on the printed circuit board by scanning against a metal mask, and the electronic component mounting means includes a plurality of electrodes of different sizes. A flip-chip mixed mounting apparatus, wherein electronic components including flip chips are mixedly mounted on a solder paste transferred onto a pattern.   14. The flip-chip mixed mounting apparatus according to claim 12 or 13, wherein a member for controlling solder paste dischargeability is formed in the opening of the metal mask, and the sizes formed on the printed circuit board are different. A flip chip mixed mounting apparatus, wherein an amount of solder paste necessary for connection of each electronic component including the flip chip is transferred onto a plurality of electrode patterns via a member for controlling the solder paste dischargeability.   14. The flip chip mixed mounting apparatus according to claim 12, wherein a hydrocarbon film exhibiting liquid repellency is formed as the liquid repellent film.

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