KR20080010479A - Soldering paste printing system - Google Patents

Abstract

A soldering paste printing system is provided to reduce print failure by restoring the failed units with a dispenser unit by inspecting printed boards through an inspection unit when the failures exist in the printed portions. A soldering paste printing system includes an accumulation unit, a detecting unit, an analyzing unit, and a process unit. The accumulation unit memorizes, accumulates, and preserves a factor of failure and a process method about the factor of failure. The detecting unit grasps and tests a state of the factor of failure before performing soldering paste print by a printing unit(200). The analyzing unit discerns and predicts possibility of failure. The process unit removes the factor of failure.

Description

Solder Paste Printing System {SOLDERING PASTE PRINTING SYSTEM}

The present invention relates to a screen printing apparatus, and more particularly, to a printing apparatus for printing solder paste and a printing system using the same.

As a conventional screen printing machine, there exist some which are shown by Unexamined-Japanese-Patent No. 5-200975. The screen printing machine includes a substrate loading conveyor, a substrate carrying conveyor, a stage portion having a lifting mechanism, a mask having a transfer pattern as an opening, a squeegee, a squeegee lifting mechanism, and a squeegee head having a horizontal moving mechanism, and a mechanism for controlling these mechanisms. After the control device is carried in the device and the substrate is mounted on the mounting table of the stage, the stage is raised to bring the substrate close to the mask, and the mask is brought into contact with the substrate by a squeegee. Printing is performed by filling a paste, lowering a stage, separating a board | substrate and a mask, and transferring a paste on a board | substrate, and carrying out a board | substrate from an apparatus after that.

Further, as described in Japanese Patent Laid-Open No. 2000-62140, a solder paste is printed on a substrate or the like through a screen by using elastic squeegee rubber.

Further, as described in Japanese Patent Application Laid-Open No. 10-086327, the squeegee body has a structure in which a metal plate is bonded to rubber to contact a rubber part with a mask, and conversely, the metal plate part is in contact with a mask. It is disclosed in 07-011338.

In addition, Japanese Patent Application Laid-Open No. 2004-338248 proposes a method for abutting an elongate member against a printed matter on a printing table and measuring the thickness from the elongated amount of the elongated member in order to measure the thickness of the substrate.

In addition, in order to recognize the marks of the substrate and the mask with a camera and to positionally correct the amount of misalignment on both sides, and to position the substrate on the mask, positioning is required at a high speed and with high accuracy, and alignment based on a normalized cross correlation coefficient is required. A joke template matching method is performed. As an example of template matching, there is a method disclosed in Japanese Patent Application Laid-Open No. 02-642 or 61-74082.

In Japanese Patent Laid-Open Nos. 5-200975 and 2004-338248, the printing result is processed correctly by managing the amount of the solder paste. However, in the conventional solder coating process using the screen printing method, the consumption of the squeegee metal mask to be used is reduced, the state, viscosity, supply amount, supply position of the solder paste to be supplied, change of cleaning condition of the metal mask, Print defects may occur due to changes in temperature and humidity during printing, positional shift due to difference in manufacturing accuracy between the printed board and the metal mask, and warpage and twist of the printed board.

For this reason, there is an increasing demand for using an apparatus for inspecting the appearance of printed solder for the purpose of observing the appearance of solder printing after solder paste printing and excluding defective products. In particular, a large number of electronic components, called CSPs and BGAs, have recently been adopted. Since the terminal parts are behind the parts after the parts are mounted, they cannot be inspected by the solder appearance inspection device. It is necessary to inspect the appearance.

After solder paste printing, even if the appearance of solder printing is observed, even if OK, the lifting failure and soldering of the electronic parts due to mismatch between the amount of solder and the mounting pressure at the time of mounting the electronic component, or the difference in the accuracy of the solder print position and the mounting position Because of the occurrence of balls, it is necessary to inspect the appearance after soldering. As a result, it is necessary to go back to the whole process and change the printing conditions or to remove the bad solder paste. There was a problem that a long yield situation was bad.

In addition, the rubber squeegee of Japanese Patent Application Laid-Open No. 2000-62140 or Japanese Patent Laid-Open No. 10-086327 tends to wear off the edge portion, and the squeegee replacement was required at about 1000 printing times. On the other hand, in the case of a large-diameter pattern opening, the squeegee crawls into the mask opening due to the flexibility of the leading edge portion to cut out and scrape the printing paste, resulting in a thin printing film and causing printing defects called red dots.

In addition, by using a metal squeegee made of a thin metal plate as in Japanese Patent Application Laid-Open No. 07-011338, by not displacing the edge portion locally, it is possible to reduce printing defects due to the cutout caused in the case of the rubber. However, it was difficult to set the plate thickness, the length of the underhead from the squeegee holder, the strength of the waist, and the like.

In the alignment of the substrate and the mask, the method described in Japanese Patent Application Laid-Open No. 02-642 required the user to judge which part should be a template, and the user had to be skilled and uncomfortable. On the other hand, according to the method of Japanese Patent Laid-Open No. 61-74082, the optimal template can be automatically registered, but the user must determine the size of the template in advance, and whether or not it is the true size of the mark is certain. It did not, however, cause a recognition error or a decrease in positional accuracy.

As a dictionary for template matching, a user has previously designated shapes such as a circle and a square with respect to the shape of a mark used for a substrate. In addition, in order to determine the size of the template, it is necessary to input a mark dimension. When performing position calculation with a precision of ± 0.01 mm, a dimension input of up to 0.001 mm is required, but it is difficult to input correctly.

Accordingly, the present invention provides a screen printing apparatus which enables a user to easily operate and obtain high alignment accuracy in ultrafine pattern printing for use of devices such as 0.4 mm pitch CSP, 0603 chip component, and 0402 chip component. The present invention provides a method of registering a reference pattern for image recognition alignment or a method of image recognition alignment, and at the same time obtains stable squeegee performance against micro displacement factors such as substrate irregularities, mask flatness, and squeegee parallelism. In addition, the squeegee for screen printing apparatus which can be used simply by the user by improving the solder filling power and reducing the load on the mask to secure the transfer amount in the ultra fine pitch printing in the low printing pressure printing can be obtained. And a screen printing apparatus equipped with the squeegee.

In addition, the defects caused by the solder paste printing process are monitored for the deterioration of the yield caused by the solder paste printing process before printing the solder paste, and the production quality is predicted and detected due to the defects. The present invention provides a solder paste printing system that improves production efficiency and yields by providing quality forecasts and warnings, and removing and treating defects early.

In order to achieve the above object, the present invention provides a printing unit for applying a solder paste on a substrate surface through a mask, the accumulating means for storing, accumulating, and preserving, as new knowledge, elements resulting from defects and processing methods for each element; , Monitoring means for identifying and inspecting the state of the element caused by the defect, before analyzing the solder paste printing, analytical means for determining and predicting whether each element is likely to cause the defect, and the analysis result It is characterized in that it is provided with a processing means for sending a forecast and alarm to the operator to remove the cause of failure.

In addition, the solder paste printing system is provided with an external device for inspecting the appearance of printed solder or an external device for inspecting the appearance of solder to feed back to the printing unit, and retains and uses the information as a new knowledge for optimum solder paste printing for new products and parts. The communication means for communicating the information of the result of the inspection by the inspection means to the printing apparatus and the information of the result of the inspection by the inspection means are analyzed so that new bad cases are frequently stored and added to the accumulation means as new knowledge. Characterized in that it comprises a re-analysis means in charge of. Also, a plurality of dispenser units for applying solder paste partially downstream of the printing apparatus in the solder paste printing system so as to automatically repair a defective portion from the inspection result, and a plurality of rework units for correcting a solder defect. It characterized in that the configuration is arranged.

Moreover, in the screen printing machine used for the said printing system, the intermediate part of the squeegee was made into urethane, the site | part which contacted the screen was made into the metal, and the metal front-end part was provided with the end attachment shape. As another method, a metal integral squeegee having a bellows shape at the middle of the squeegee and a stepped end fitting shape is provided at the front end.

Moreover, at the time of printing, even if a similar pattern exists around arbitrary patterns, the means for automatically selecting the correct reference pattern was provided.

The dictionary area for template matching is provided with means for the user to automatically register as a reference pattern without setting a mark shape or mark dimension.

With the above configuration, various patterns used for alignment of the substrate and the mask can be easily handled without requiring skill, and furthermore, even if disturbance fluctuations occur during printing by improving the printing alignment accuracy. The stable squeegee performance improves print yield, contributing to stabilization of print quality and reduction of defects. In addition, the printing film thickness is stabilized and the printing thickness is secured even at low printing pressure printing. Moreover, distortion distortion of a mask is reduced and it contributes to high precision printing. Contributes to the prevention of deformation and long service life of ultra-thin masks.

In addition, the printing yield is improved by monitoring the factors that will result in the printing failure before making printing, giving a bad forecast, and eliminating the defect factor. By accumulating and analyzing the inspection information after printing, it is possible to accumulate new defect information data so that the accuracy of the defect forecast can be improved and the range of the detection failure mode can be improved, and if the defect can be corrected, the defect is automatically corrected. The printing yield is improved.

As mentioned above, in this invention, before printing on a board | substrate with a normal printing unit, quality is predicted by the quality prediction system which a printing unit has, and if there is no problem, printing is performed. This enables printing with high yield at high efficiency. In addition, if the printed board is inspected by the inspection unit and there is a defect in the printed portion, and the defect that can be repaired, it is possible to repair the dispenser unit, thereby reducing the printing defect.

In addition, since each unit is configured in units, the layout can be easily changed.

In addition, even when it is necessary to print by using different types of solder paste or adhesives by combining the printing unit and the dispenser unit, it is not necessary to prepare and print a plurality of different masks, thereby eliminating the work time such as replacing the mask and printing time. It is possible to contribute to high-density installation by aiming at shortening the time and increasing the degree of freedom of design and process.

In addition, since the conventional printing press, dispenser apparatus, and inspection apparatus were independent of each other, it was necessary to mount a data input apparatus, a display apparatus, a data storage apparatus, and the like on each of them, but the system configuration can make them common. It is also possible to miniaturize the device.

Fig. 1 shows the arrangement of the devices of the solder paste printing system of the present invention.

As a representative example of the printing system of the present invention, in addition to the screen printing unit 200, an inspection unit 300 that inspects the results printed by the screen printing unit (hereinafter referred to as a printing unit) 200, and in some cases, inspection When the unit 300 detects a printable state that can be repaired due to a printing failure, the unit 300 is provided with a plurality of dispenser units 400 for repairing it.

Conventionally, in the case of applying the solder paste, after supplying the solder paste applied by the printing unit 200 onto the mask surface and completing the preparation, after teaching the recognition mark position, the automatic operation is started to print the solder paste, and then the downstream apparatus. The board | substrate was conveyed to. On the other hand, accumulating means for storing, accumulating, and storing the elements resulting from the defect and the processing method for each element as in the present invention, and the state of the element resulting from the defect before printing the solder paste, as in the present invention. Monitoring means for identifying and inspecting the product, analytical means for determining and predicting whether or not each element is likely to cause a defect, and a quality forecast and warning to the operator based on the analysis result to remove the cause of the defect. By providing the processing means, it is possible to automatically predict and repair the production quality before printing, thereby maintaining the production quality and preventing the defect from flowing downstream. In addition, by combining the printing unit 200 and the inspection unit 300, it is possible to accumulate new defect information data.

There are the following typical items as a factor resulting from the occurrence of a printing defect.

(1) Wear conditions of squeegee and mask, (2) Damage of mask, lack of tension, clogging of opening, (3) Solder condition (supply amount, supply height, supply position, supply width, air mixing), (4 ) Solder condition (viscosity, tacking, temperature, degree of drying), (5) environmental temperature and humidity in the printing unit, and (6) dimensional unevenness, curvature and twisting of the substrate for production.

As the processing method for each of the above elements, there are the following representative methods, respectively.

(1) Replace the squeegee mask with a new one, (2) Replace the mask with a new one, clean the clogged area, (3) and (4) supply or roll a new solder after collecting the old solder, (5 ) Temperature and humidity control, (6) Selection and discharge of defective substrates.

As to the wear condition of the squeegee mask of (1), it is conventionally dependent on visual confirmation of the spot by a skilled person, or test printing several times after supplying the solder paste from the printing unit 200, and is there any problem in the printing result? Production was commenced after visual confirmation or other inspection.

According to the method of the present invention, the number of times of use is counted by the monitoring means by a printing number counter for the squeegee masks and substrate varieties used in the production, and the number of times of use at the time of the occurrence of defects as statistical information of past defect rate occurrences. Based on the accumulated information, the information is input and accumulated, and the analysis means compares and analyzes the past occurrence of the defective rate with the present number of times of use, and displays estimated estimated defective rate information on the monitor of the printing unit as a quality forecast. By doing so, the operator can easily determine whether production can be started without any problems.

As an example of varietal management such as the applied squeegee and the material of the mask, identification information (three-dimensional bar code, etc.) marked on the squeegee, the mask and the production substrate is automatically read or manually inputted by an information reader provided in the printing unit. Simple to manage

The usage limits of the squeegee and mask are conventionally controlled by the number of print shots produced or the period of use, but, for example, the squeegee material, hardness, material of mask, etc. The density coefficients such as the plate thickness and the adjacent mounting conditions of the boards for production are regarded as relevant coefficients, and the predicted failure rate prediction map is prepared using the analysis means in the printing unit, and compared with the current usage count. Thus, it is possible to display the estimated defective rate information as the quality forecast at this time.

In addition, when it is determined that the usage failure limit is compared with the target failure rate for the production substrate varieties set and input in advance in the manager function with respect to the failure occurrence rate prediction diagram, and is currently used, the squeegee is displayed as a quality forecast on the monitor of the printing unit. By displaying a replacement recommendation mark, the operator can start production after replacing the applied squeegee or mask with a new one without identifying or confirming production.

Next, about the damage of the mask of (2) and clogging of the opening part, OK / NG determination is possible by performing shape recognition of each printing pattern part using the recognition camera with which the printing unit was equipped. In addition, the tension OK / NG determination is possible by pressing the tension measuring rod provided in the print head with a predetermined thrust and pressing a predetermined part of the mask, and measuring the generated reaction force at this time with a load cell. None of the methods devised in this document is not only a simple OK / NG determination, but also an accumulation means by accumulating information by measuring the actual area of the opening and the tension reaction force by the monitoring means by the recognition camera. In accordance with the production performance information of the SMT line, the predicted failure occurrence map is generated by the analysis unit of the printing unit to display the quality forecast. By measuring all before production starts, it is possible to contribute to the prevention of defects by estimating the occurrence of print defects at the present time and displaying the quality forecast on the monitor of the printing unit. When clogging of the mask opening is detected, any clogging portion on the mask can be automatically cleaned by the subplate cleaning apparatus as the processing means.

In (3), the operator regularly monitors visually whether the supplied solder paste is an amount that can be applied without a problem, and whether there is no problem in the position of the supplied solder paste. On the other hand, according to the method of patent document 1, the printing machine which alerts and does not require the monitoring work of the solder paste amount and can replenish solder paste is devised. However, it is difficult to prevent print defects in reality unless air is mixed in the solder paste supplied.

Therefore, a large opening is arranged near the printing stroke end of the mask, and the printing unit 200 is used by using a mask with a transparent material so that the solder paste does not fall to this portion and the state of the solder paste can be monitored from the bottom. Monitoring the state of the solder (supply amount, supply position, supply width, presence of air) before starting production by monitoring the supply state of the solder paste on the mask through the transparent material through the transparent material. It becomes possible. Of course, even during automatic operation, monitoring and confirmation can be automated similarly at intervals set in advance as printing conditions.

The state of the solder paste is confirmed by the monitoring means by the recognition camera. After that, the analysis means analyzes the cause of failure due to the state of the solder paste (supply amount, supply position, supply width) based on the database information and the confirmation data of the accumulation means. In addition, the analysis means checks the consistency by comparing the squeegee information, varietal information of the production substrate with the state of the solder paste. For example, if the solder supply width dimension is inconsistent with the squeegee dimension and the substrate dimension, the quality forecast is displayed. In addition, by providing a solder paste supplying syringe in the printing unit, it is possible for the processing means to replenish an appropriate amount of solder paste in a portion where the solder paste is insufficient.

When the monitoring means detects bubbles in the solder paste, a quality forecast is displayed, and as a processing means, bubbles are removed by rolling the solder paste by automatically performing a reciprocating squeegee operation using a dummy substrate. Can be.

Also, in (4), there is no problem in the viscosity of the supplied solder paste or the tagging property of the supplied solder paste is not deteriorated. It was common practice to manage by the leaving time of the solder paste removed from the refrigerator. Viscosity and tagging cannot be measured directly by non-contact, but viscosity and tagging correlate with temperature and degree of drying, and the correlation value information is accumulated in the accumulating means to detect the temperature and dryness of the solder paste. As a monitoring means for monitoring, by arranging and using infrared thermography in a printing unit, the temperature nonuniformity of the surface state of the solder paste supplied is measured, and it is always non-contacted to monitor whether there is any part which causes a printing defect by drying in pieces. It is possible.

When the deterioration state of the solder paste is detected by the monitoring means by the infrared thermography, the yield improvement can be achieved by replacing the deteriorated solder paste before displaying the quality prediction by the analyzing means and causing the printing failure.

(5) In case of defects caused by environmental temperature and humidity change in the printing unit, there is no sudden change in temperature and humidity by monitoring means by one or more temperature and humidity sensors arranged inside the printing unit. If there is any unevenness in the distribution at all times, and if it is determined by the analyzing means based on the information by the accumulating means, a quality forecast is displayed. In addition, by providing a temperature and humidity control device in the printing unit to automatically perform temperature and humidity control as processing means, automatic adjustment of temperature and humidity is possible. As another example of the monitoring means, the entire surface of the metal mask may be subjected to temperature distribution measurement by means of infrared thermography, and the performance data may be stored and used in the storage means.

(6) Defective factors due to dimensional unevenness, warpage and twist of the production substrate are judged as NG when the distance between the marks is non-uniform with respect to the reference dimension when the recognition mark is recognized. It is possible. In addition, the bending and torsion can be detected by measuring and comparing two or more places such as a substrate edge part by applying the method proposed in JP-A-2004-338248.

When the abnormality is detected by the monitoring means, the quality prediction is displayed by the analyzing means, and a defective substrate stocker is installed as a processing means, and the defective substrate is discharged from the printing unit to be selectively managed to prevent the defective product from flowing into the production line. It becomes possible.

Thus, the monitoring means by the sensor which can detect the element about the typical printing defect of (1)-(6) is always monitored and detected, and the analysis means responds to the representative defect factors and measures of (1)-(6). In the case where it is determined that the quality is predicted to be a defect by analyzing and accumulating the information and accumulating the information in the database, it is recommended to improve the yield by preventing processing defects such as print shortages. It becomes possible.

In addition, after printing to the printing unit 200, the printing unit is inspected by the inspection unit 300 to check the presence or absence of a defective location, and if there is a defective location, the defective information is transmitted to the printing unit by a communication means (not shown). In addition, it is also possible to improve the yield of the printing system by transmitting to the repair dispenser unit 400 and repairing a defective point. That is, a suction dispenser is installed in at least one unit of the dispenser unit in which a plurality of solder pastes are applied with extra solder paste in the printing unit as one of the repair dispensers, and there is a spare There exists a structure which repairs by absorbing a solder paste. In addition, at least one dispenser unit is provided with a dispenser for supplying a solder paste of the same type as the solder paste used for printing, in which the soldering unit is not sufficiently supplied with the solder paste and the solder paste is provided therein. There is one configured to further apply the paste.

As the combination of the above-mentioned units, as shown in Fig. 1A, the printing unit 200 and the inspection unit 300 are integrated to measure the substrate manufacturing dimensional accuracy before printing starts, and then, if there is no problem, printing starts. In the event that a failure is foreseen, an alarm may be immediately issued to exclude the defective product and to be discharged to the inspection stocker not shown. In addition, since the state immediately after printing can be immediately observed and inspected by the inspection unit, a more accurate inspection can be performed at a stage where the surface state of the solder paste does not change due to temperature or wind.

As shown in FIG. 1 (b), printing is omitted by integrating the printing unit 200 and the inspection unit 300 so as to connect one or a plurality of dispenser units 400 to the downstream side of the inspection unit 300. In addition to this, it is also possible to apply coatings with other types of solder pastes, and to reduce printing costs. In addition, by providing a plurality of dispenser units, it is possible to shorten the tact time by allowing the other dispenser units to apply only the coating range in charge of the dispenser unit at the same time. In addition, the printing which was conventionally possible only on the substrate surface can be applied to the inner surface and the bottom surface of the substrate recess. In this configuration, at least one of the plurality of dispenser units 400 installed in this configuration is provided with a dispenser for applying an adhesive to improve the degree of freedom in design in the manufacture of a printed board in which a large part and a chip part are mixed. It becomes possible. That is, conventionally, the solder paste is printed by the printing unit 200 after the component mounting surface is intensively designed on one surface, and then the adhesive is applied on the dispenser unit 400 to attach the chip component to the back. It becomes possible. That is, a dispensing machine can be used to apply dissimilar materials such as a conductive adhesive even in a narrow region. For this reason, the mounting area may have to be divided according to the conventional chip component surface, the large component surface, and the production process. Therefore, the circuit design has been limited. However, by combining the printing unit 200 and the dispenser unit 400 as in the present system and applying the adhesive to one of the dispenser units, the degree of freedom in design can be improved and more dense installation is possible. Although not shown, it is also possible to arrange a plurality of dispenser units 400 without arranging the printing unit 200 and to arrange the inspection unit 300 on the downstream side thereof. In this configuration, however, the printing time is much larger than that of the configuration using the printing unit 200. However, the problem can be solved by providing a plurality of process divisions. Further, in each of the above configurations, at least one of the plurality of dispenser units 400 provided in the above structure is provided with a suction dispenser for suctioning and removing excess solder paste applied on the substrate instead of the dispenser for repairing the defective printing substrate there. As a result, the printing yield can be significantly improved.

As shown in Fig. 1C, the printing unit 200, the inspection unit 300 and one or more dispenser units 400, and the downstream mounting unit 500 and reflow soldering on the downstream side thereof. By configuring the inspection unit 300 and the rework unit 700 after soldering on the downstream side of the apparatus 600, it is possible to collect the defect factor information due to the printing on the product for which the entire process of the surface mounting process is completed. In addition, when rework is possible based on the information of the inspection unit 300 for inspecting the appearance of soldering, spot soldering or the like can be performed on the solder failure site by the rework unit 700.

Next, the configuration and operation of each unit will be described.

The structure of the printing unit which consists of the screen printing apparatus in this invention in FIG. 2, FIG. 3 is demonstrated. Fig. 2 (a) shows a configuration and a system configuration diagram seen from the front of the screen printing apparatus. In addition, the block diagram of the structure which looked at the screen printing apparatus from the side, and a printer control part is shown in FIG.2 (b). 3A shows a state in which the substrate is loaded and aligned with the screen printing apparatus viewed from the side, and FIG. 3B shows the state during printing.

The plate frame is provided in the main body frame, and the plate frame is configured such that a mask 20 having a screen 21 having a printing pattern as an opening portion is set. A squeegee head 2 is disposed above the mask 20, and a squeegee 3 is attached to the squeegee head 2. The squeegee head 2 is movable in the horizontal direction by the squeegee moving mechanism 6, and the squeegee 3 can be moved in the vertical direction by the squeegee lifting mechanism 4. Below the mask 20, a printing table 10 for mounting and holding the substrate 5, which is a printing object, is provided so as to face the mask 20. The printing table 10 receives an XYθ table 11 for moving the substrate 5 in the horizontal direction to align the mask 20 with the mask 20, a substrate 5, and a substrate 5 from the conveyor 26. A table elevating mechanism 12 is provided for bringing 5 close to or in contact with the surface of the screen 21. The substrate receiving conveyor 26 is provided on the upper surface of the printing table 10. When the substrate 5 carried by the substrate loading conveyor 25 is received on the printing table 10 and printing is completed, the substrate carrying conveyor ( 27, the substrate 5 is discharged.

The fully automatic screen printing apparatus has a function of automatically aligning the mask 20 with the substrate 5. That is, the CCD camera 15 picks up the image alignment mark provided on each of the mask 20 and the board | substrate 5, and image-processes, calculates the position shift amount, and corrects the shift amount. ) To perform alignment.

In addition, the printer control unit 30 including the printing control unit 36 for driving each unit, the image input unit 37 for processing the image signal from the CCD camera 15, or the like is provided inside the main body frame of the printing machine to control the data. The data input unit 45 for rewriting, changing the printing conditions, and the like, and the display unit 40 for monitoring the printing status or the like and the introduced recognition mark are disposed outside the printing press.

Next, the operation of the printing apparatus of the present invention will be described.

The board | substrate 5 which receives the cream solder is supplied to the board | substrate receiving conveyor 26 by the board | substrate loading conveyor 25, and is fixed to the predetermined position on the printing table 10. FIG. After fixing the substrate, the CCD camera 15 is moved to a substrate mark position which is registered in advance. Subsequently, the CCD camera 15 picks up the position recognition mark (not shown) provided in the board | substrate 5 and the mask 20, and transmits it to the printer control part 30. FIG. The image signal input to the image input unit 37 in the control unit recognizes a mark using data of the dictionary unit 38 registered in advance in the correlation value calculating unit 31 and the shape estimating unit 32, and the position coordinate calculating unit ( 33) The position calculation amount of the mask 20 and the board | substrate 5 is calculated | required by the dimension calculation part 34, and based on the result, the XY (theta) table control part 35 operates the XY (theta) table 11, and the mask 20 is carried out. The position of the substrate 5 with respect to is corrected and aligned. After completion of the alignment operation, the CCD camera 15 is evacuated by a predetermined amount to a position where it does not interfere with the print table 10. After completion of evacuation of the CCD camera 15, the print table 10 is raised to bring the substrate 5 and the screen 21 attached to the mask 20 into contact with each other. Thereafter, the squeegee 3 is lowered onto the screen surface by the squeegee lifting cylinder 4, and the solder paste 50 supplied on the screen 21 is moved to the opening of the screen 21 by the movement of the squeegee head 2. It is charged and transferred to the substrate 5. The squeegee 3 ascends after a predetermined distance stroke in the horizontal direction. Then, the printing table 10 is lowered, the screen 21 and the substrate 5 are separated, and the solder paste 50 filled in the opening of the screen 21 is transferred to the substrate 5. Subsequently, the substrate 5 on which the solder paste is printed is passed through the substrate transport conveyor 27 to the next process.

In addition, the substrate 5 and the mask 20 are provided with two or more recognition position alignment marks at relatively same portions, and each of these marks is provided by a special CCD camera 15 having two views in the vertical direction. The mark of the mask 20 is recognized from the bottom, the mark of the substrate 5 is recognized from the top, and all position coordinates of the mark of the predetermined portion are read out to calculate the amount of displacement of the substrate 5 with respect to the mask 20. By correcting, the substrate 5 is positioned with respect to the mask 20.

In the printer control unit 30 shown in FIG. 2B, the dictionary 38 is introduced even when a similar pattern exists around the arbitrary pattern by introducing an arbitrary pattern captured by the CCD camera 15 from the image input unit 37. The correlation value between the model prepared in advance and the arbitrary pattern picked up by the CCD camera 15 is calculated by the correlation value calculator 31. The shape estimation unit 32 estimates the shape of the model based on the correlation value obtained by the correlation value calculation unit 31. The estimated shape is stored and set as a plurality of temporary reference patterns. The pattern position coordinate calculating section 33 compares the distance between the target reference patterns and obtains the shape dimension in the dimension calculating section 34, and registers the mark of the combination with the smallest difference as the reference pattern in the dictionary 38. Means are provided.

An example of the prior model prepared previously in FIG. 4 is shown. Here, pre-models of round, square, and equilateral triangles are used, but various shapes such as ridges, rectangles, and concave shapes can be employed.

In the past, model registration was carried out by actually selecting and using a pattern shape suitable for a production substrate from a pre-model called an artificial model. In addition, the accuracy of template matching is ensured by inputting the pattern outline dimensions.

5 shows an example of a correlation map in which template matching is performed when a similar pattern exists around an arbitrary pattern. The site | part which shows the largest peak of the correlation value in a figure becomes a 1st candidate used for search. The second peak is the second candidate, and similarly, the third peak is the third candidate. Here, the one-dimensional correlation map is taken as an example, but the same result is obtained by using other known techniques of the two-dimensional correlation. In this example, even the third candidate is obtained, but the number of candidates can be arbitrarily specified.

Even if a similar pattern exists in the search result of FIG. 5, three candidates within an arbitrary window can be selected. However, since no dictionary for the mark shape applied to the production substrate is specified in the artificial model or the like, it is naturally difficult to determine which of the three candidates is the correct mark.

6 shows a state in which candidate marks are selected in each window from the search results of FIG. 5 in the case where two recognition patterns are arranged in the substrate 21. Since there are two patterns for recognition, there are also two window areas. As a result of mark search in the window 1 (W1), three candidates (Ml1, M12, M13) are selected, and as a result of mark search in the window 2 (W2), three candidates (M21, M22, M23) are selected. do.

6 shows the mark search results on the substrate 5, the marks corresponding to the two recognition patterns of the substrate 5 are arranged on the mask 20 side, which is not shown in the figure.

As the pattern for recognition on the mask 20 side, a conventional mark (an independent reference mark) in which a resin for imparting contrast at the time of recognition is usually used in the through hole or half etching or through hole or half etching portion. There are many cases where a similar pattern does not exist around the recognition pattern on the mask side. Therefore, even inexperienced users can easily determine whether there is a factor of misrecognition.

Therefore, in the case where the similar pattern does not exist in the periphery of the recognition pattern in the mask 20, the method described in FIG. 5 is used, and the condition that the match rate (predetermined score for the correlation value) is equal to or greater than a predetermined value is used. It can be judged as a pattern for recognition of the mask which the pattern with the highest correlation value which has a match rate more than predetermined value by having is provided.

In this case, since the center coordinate relationship between the window 1 (W1) and the window 2 (W2) is set and input to the printing apparatus as known data in advance, it is for recognition in each window obtained from the correlation search result. By calculating the center coordinates of the pattern by the position coordinate calculating unit 33, the position coordinate calculating unit 33 can calculate and calculate the distance ML between the mask recognition patterns M1 and M2.

Since the L dimension shown in FIG. 6 is the distance between the marks of M11 and M21, and the design value of L is the same as the above-mentioned ML, ML can be used as a selection reference value.

The process flow in a correlation value calculation part-a position coordinate calculation part is shown in FIG. In this process, it is a case where three windows are set in two places. According to FIG. 7, it is possible to obtain | require the mark whose L dimension is closest to ML among the combination of the mark candidates of the window 1 (W1) and the window 2 (W2) by the position coordinate calculating part, and register it as a reference pattern. In Fig. 7, the start is searched from the No. 1 window. That is, first, the number of windows W is set (step 110). Next, the Nth candidate is searched (step 111). When the Nth search is finished, the next candidate is determined (add 1 to N to become N + 1st candidate: step 112). It is checked whether N is exceeding the maximum number of candidates (step 113). If not, the process returns to step 111 where the Nth + 1st candidates are searched for. If it is exceeded, it is checked whether all windows have ended (step 114). If all windows are not closed, the window is set to the next window (W + 1) (step 117), and the process returns to step 110 for setting the window number. When the search of all windows is completed, the respective distances when the Nth candidate of the window W mark is combined with all the candidates from the Nth to N + 3th marks of the next window (W + 1) mark. (Lnn) is obtained (step 115). Record the result as in step 118. The difference between the known L and the obtained Lnn is calculated, and the smallest candidate is selected and registered.

In addition, when a physical mark is not used for the recognition pattern on the mask side, since the similar pattern exists in the periphery of the recognition pattern, the said ML cannot be used as a selection reference value. In such a case, instead of the said ML, you may calculate and use the selection reference value L from the mark coordinates and board | substrate dimension previously input to a printing apparatus.

Next, the correlation value calculation unit 31 and the correlation value calculation unit 31 which calculate a correlation value between the dictionary model and the arbitrary pattern recorded in the dictionary 38 prepared in advance using FIG. 8 to FIG. On the basis of the correlation value determined by the above, the screen printing apparatus characterized by comprising a shape estimating unit 32 for estimating the shape of the model and a dimension calculating unit 34 for performing an image measurement operation on the dimensions of an arbitrary pattern. do.

In FIG. 8, the case of Lx = Lx1 is shown about the inspection and dimension correction after mark dimension measurement. As shown in the figure, after the mark arithmetic processing, the mark is moved by giving a movement command to the print stage a distance equal to the mark outline dimension with respect to the X direction. Next, mark edge coordinates are read out, and the mark movement amount is calculated from the mark edge coordinates before the movement and the mark edge coordinates after the movement previously stored before the movement. When the mark X direction outline dimension Lx which measured the dimension is the same as mark edge movable amount Lx1, it determines with the mark dimension measured by the dimension being accurate.

In FIG. 9, the case of Lx <Lx1 is shown about the inspection and dimension correction after mark dimension measurement. When the mark X direction outline dimension Lx measured by dimension as shown in this figure is smaller than mark edge movement amount Lx1, it is judged that the mark dimension measured by dimension is not accurate.

10 shows a processing flow in the dimension calculating section and the dimension correcting section. 10 may perform the same process also about the specific process flow of the dimension correction of the X direction, and the Y direction. That is, after performing arithmetic processing in a X direction, arithmetic processing is performed similarly to a Y direction.

In this process, first, the external dimension of the mark of the Nth candidate is measured (step 210). In this case, a is set in the X direction (step 211). The stage is moved in the a direction to obtain a movement amount (212). The distance La1 from the end of one mark to the start of the movement to reach the other edge portion is measured (step 213). It is determined whether the movement distance is equal to the predetermined value La (step 214). If not equal, a correction value La / La1 is obtained (step 216). After the correction value in the X direction is found, a is replaced by y (steps 215 and 217) to perform the same processing.

By the way, the camera coordinate system of the printing apparatus is calibrating the absolute precision of a mechanical drive system using the ultra-high definition and direct drawing (photomask) used for semiconductor manufacture. For this reason, the accuracy when moving a camera to an arbitrary position by the command value is fully trusted. In addition, even when a technique such as a full-closed servo system using a linear motor or the like is used, the distance of camera movement is sufficiently reliable.

Therefore, by using the above technique or the like, it is possible to determine whether or not the dimensions of the image read by the camera are correct. It can also be applied to camera resolution and self-diagnosis.

In addition, when the alignment method according to the present invention is used, the mark size read before the alignment during the production operation and the mark position after the alignment table are moved are inspected and determined, and the mark size is measured. Therefore, automatic calibration is possible from the failure diagnosis of the camera of the printing apparatus at all times.

Therefore, by using the positioning method according to the present invention, not only can the device be non-stop diagnosed at all times without any accuracy abnormality during production, but also automatic calibration can be performed.

As described above, in the present invention, it is possible to register a mark as a reference pattern without designating a mark shape or mark dimension for an arbitrary pattern.

In addition, even if the number of skilled workers is decreasing, even inexperienced users can secure the shortened and accurate reference mark registration time easily and can contribute to the efficiency and productivity of high-density installation production. Become.

In addition, it is clear that the present invention can also be applied to alignment of a substrate in a mounter or the like which does not use a mask.

In addition, by using the present invention, the reference mark registration method that has been used among the devices in the SMT line can be made uniform and common, and the operation method of each device can be simplified and made common.

The printing press control part has a printing pressure control part which controls the printing pressure which is not shown in figure, and can easily select an appropriate printing pressure according to the difference of the installation density and aperture diameter of the board | substrate to produce, and the spring constant of the squeegee used. In addition, feedback control is performed so that the pressure at the tip of the squeegee pressed against the substrate via the mask does not change.

Next, the squeegee used for the screen printing apparatus of this invention and the screen printing apparatus equipped with the squeegee are demonstrated using FIG. 11, FIG.

An example of a composite metal squeegee is shown in FIG.

The squeegee holder is divided into two, the second squeegee holder 52 holding the squeegee 3 and the first squeegee holder 51 provided on the driving part side, and the elastic member 53 is disposed therebetween. will be.

The squeegee 3 part which contacts the screen 21 is comprised from metal. The elastic member 53 of the intermediate part of a 1st squeegee holder and a 2nd squeegee holder is formed with the urethane rubber of 80 degree of hardness. Moreover, the squeegee 3 was made into the metal squeegee of an edge part, it made it durable by making the thickness of the squeegee holder side into the metal plate of 0.25 mm, and the thickness of the front-end part was 0.05 mm. In addition, by producing the metal squeegee by the additive method, the ridge roughness of the leading edge portion can be produced with high precision at 0.5 µm or less.

As in the case of screen printing shown in FIG. 12, the thickness of the circuit resist pattern resist 55 coated on the surface of the substrate 5 is about 20 μm, and is covered around the electrode pad 56 portion of the printed substrate. There is a case, resulting in a gap between the screen 21 and the electrode pad 56. Silk printing 57 is also provided on the resist 55 to indicate device numbers, substrate names, and the like. Since the thickness of the silk print 57 is 30 to 40 mu m thick, when combined with the thickness of the resist 55, a gap of about 50 to 60 mu m occurs. If there is no force to fill the solder paste 50 when printing the solder paste 50 for a gap having a depth of about 20 to 60 μm from the surface of the screen 21 to the surface of the electrode pad 56, the electrode pad 56 may be used. Since the solder paste 50 does not reach the surface, the untransferred portion is generated.

According to the present invention, a force for filling the solder paste 50 may be generated by using a repulsive force against the bending stress of the urethane rubber part constituting the elastic member 53. With respect to the printing pressure P in Fig. 12 (b), since F1 and F2 are F1 = P · COSΘ and F2 = P · COSΘ, respectively, since the urethane rubber 53 portion is bent, Θ becomes small, so that F1 <F2 becomes The force acting in the direction perpendicular to the squeegee 3 becomes large. As a result, the rolling force (moving force in the direction of the arrow) of the paste during printing is increased, and the filling force to the screen opening is increased, so that the filling of the solder paste is possible even on the electrode pad 56 having a large gap from the screen 21. It becomes possible.

In addition, since the urethane rubber portion is flexibly deformed, it is possible to easily follow not only local irregularities but also the entire substrate in a combed or concave state. This configuration solves the problem of the followability to the unevenness of the substrate in the conventional metal squeegee and the back plate attached metal squeegee. In addition, it is possible to absorb the generation of fine vibrations during the sliding of the mask and the squeegee and to provide a good printing finish surface without printing shrinkage.

In addition, the stepped end fitting metal squeegee of the metal tip does not fall into the opening hole, but it is possible to follow the displacement of the minute unevenness and the stepped portion due to the thickness of the silk printing part or the like with good sensitivity during printing. The good sensitivity at the time of printing here is the difference of magnitude of the spring constant of a squeegee. Since the period (T) of the spring pendulum is obtained by the following equation T = 2π (W / gk) ^1/2 , the larger the spring constant (k), the shorter the cycle, that is, the higher the frequency, the better the sensitivity, and thus the sensitive response Will be. On the contrary, the smaller the spring constant k, the longer the vibration period and the lower the frequency, and thus the insensitive to the reaction of the squeegee.

13 shows an equivalent spring system example of the composite metal squeegee.

When the deflection by the urethane rubber portion provided in the middle of the squeegee is δ1 and the end portion of the metal squeegee tip is δ2, only the load W applied to the tip is taken into consideration. ) And spring constant (k2) can be regarded as connected in series. The theoretical value of the deflection can be calculated if the material and the cross-sectional dimension shape used for the squeegee are known by δ = WI ³ / 3EI. In addition, according to Hook's law, k = W / δ, the spring constant can be calculated by calculation. Here, if the composite spring constant is K, it is possible to obtain the composite spring constant shown in Fig. 13 by (1 / K) = (1 / k1) + (1 / k2).

Fig. 14 (a) shows a principle explanatory drawing, and Fig. 14 (c) shows an embodiment of the spring portion of the squeegee having another spring constant. This figure is an example in which two or more spring constants were provided in the squeegee height direction by another method with respect to the invention shown in FIG. A spring-shaped elastic body (spring) is provided at the middle of the squeegee holder and the squeegee, and is formed as a spring-integrated squeegee having different bending times and different bend lengths, or a stepped end-shape in the tip portion. do. This configuration allows flexible displacement in the vertical direction as shown in Fig. 14A, and can flexibly follow the unevenness of the substrate.

By using the integrated squeegee having the spring shape according to the embodiment of this figure, the performance equivalent to that of the composite squeegee shown in FIG. 11 can be realized. In addition, the use member score can be significantly reduced than the composite squeegee, and the manufacturing method for the integrated type can be considered a variety of methods such as the additive method and the molding press, thereby reducing the cost. In addition, it is possible to reduce the squeegee mass and to generate an effective filling force at a lower printing pressure, thereby obtaining a good printing result.

Next, the case where an inspection unit is provided on the next process side after completion of printing is described.

The structure of an inspection unit is shown in FIG.

The inspection unit 300 includes a door-shaped frame provided with a linear motor drive type drive mechanism 62 (or a drive mechanism composed of a servo motor and a ball screw) that is movable on the mount 61 in a direction perpendicular to the substrate transfer direction. And a moving table 67 disposed on the frame and provided with a drive mechanism made of a linear motor 65 (or a servo motor and a ball screw) so as to be movable in the substrate conveyance direction on the frame, and for imaging. Camera 66. The camera 66 is arrange | positioned at predetermined intervals with respect to the board | substrate 5 so that the board | substrate surface may be imaged.

By the way, what is printed by the printing unit 200 described in FIG. (1) The state in which the solder paste is not normally printed on the electrode portion and a portion is partially missing. (2) The state of so-called sag, bridge, or bleeding in which the solder paste is sometimes adhered to the adjacent electrode side, and the solder paste is applied to the outside of the electrode. (3) The state in which the printing is offset with respect to the electrode as a whole.

The inspection unit 300 detects these conditions to determine what is wrong and feeds back information to the printing unit by the communication means, but at this time, the ABC evaluation is performed for various failure modes by the reanalysis means of the printing unit. By processing the information into largely classified categories, it is possible to improve the processing efficiency for judging against the database information of the accumulating means of the printing unit, and the processing time can be greatly reduced. As a method other than ABC evaluation, another statistical method may be employed. Furthermore, it is easy to finish with the necessary sufficient quality forecast information which can be easily judged by an operator from the extensive inspection information in a three-dimensional inspection unit etc. In addition, depending on the defective state, the next dispenser unit 400 is repaired to actively suppress the occurrence of the defective product.

First, the substrate 5 printed by the printing unit 200 is exchanged on the substrate receiving conveyor 63 of the inspection unit 300 connected to the substrate discharge conveyor 27 of the printing unit 200. The substrate on the substrate receiving conveyor 63 is stopped at a predetermined position to be sent and received on the substrate table 68. The board | substrate table 68 is provided with the board | substrate holding mechanism 69 (for example, a suction | suction adsorption mechanism or a mechanical chuck mechanism), and is hold | maintained so that the board | substrate 5 may not move. The inspection unit 300 is provided with a control unit 60C for determining the quality of printing by image processing from the driving unit of the inspection unit 300 and the image data captured by the camera, and the inspection unit 300 alone It is also possible to operate. However, when operating alone, the control unit 60C requires a large memory to store in advance a plurality of pattern data of printing. In the case of interlocking with the printing unit 200 or the dispenser unit 400, a large memory is required because the control unit on the printing unit 200 or the dispenser unit 400 may receive and use the print position data. I never do that.

Although not shown, a stopper which protrudes from the surface of the substrate receiving conveyor 63 to prevent movement of the substrate 5 without providing the substrate table 68 is provided, and the substrate is stopped by the stopper. It is also possible to position the board | substrate 5 in a predetermined position by stopping 63. As shown in FIG.

Next, the substrate positioning mark is observed by the camera 66. From this position, the application (printing) position of the solder paste applied by the printing unit is obtained, and the camera is moved to the solder application position to image the application state. The picked-up image is image-processed by the image processing part provided in the control part 60C, and it is judged whether the solder paste is normally printed in a normal printing position. By moving the camera 66, the inspection is performed for all the print areas. If the judgment result is normal, the print process ends there. However, if the dispenser unit 400 is provided downstream of the inspection unit 300, the dispenser unit 400 only carries the conveyance function, and the substrate 5 after the inspection is conveyed to the dispenser unit outlet.

If it is determined that the inspection unit 300 is defective, the data is transmitted to the control unit of the printing unit 200 at which point in which the state of any of the states (1) to (3) described above occurred, and at the same time, The inspection result is displayed on the display device installed in the printing unit 200. In addition, although not shown, the inspection unit 300 may be provided with a display device for monitoring input conditions, inspection conditions, and the like for changing inspection conditions. The same data is also transmitted to the control unit 70C provided in the dispenser unit 400.

In the dispenser unit 400, when the defect is (1) printing missing, only the printing missing portion is supplied with the solder paste by the dispenser to repair the missing. If the deflection, bridge, or bleeding defect is as shown in (2), the substrate is conveyed to a dispenser unit provided with a suction dispenser, and the portion is repaired by sucking and removing the solder paste of the defective portion (other than the electrode). do. If the defect is caused by the misalignment of (3), it is judged whether or not the repair is possible, and when the repair is possible, the substrate is conveyed to the dispenser unit provided with the suction dispenser as in the case of (2). Thereafter, the solder paste in the portion requiring repair is removed by suction, and then conveyed to a dispenser unit having a discharge dispenser installed in the electrode portion, where the solder paste is further applied to the electrode in the portion. In the case of the misalignment of (3), the misalignment amount is transmitted to the printing unit 200 side so that the administrator can determine whether the mask is defective or a printing mistake, and if the defect is a mask, the mask is replaced with a normal mask. If the problem is a printing problem (such as misalignment), the printing condition is corrected.

The dispenser unit has the structure shown in FIG. 16 in order to perform the above operation.

Like the inspection unit described above, the door-type frame 84 is disposed at right angles to the substrate receiving conveyor 72, which is a substrate conveying path, and a suction dispenser or solder paste is used to suck and remove the solder paste from the printing surface. Any one or both of the solder paste dispenser 83 for coating is provided. Moreover, the board | substrate table 78 for receiving the board | substrate 5 from the board | substrate receiving conveyor, and mounting the board | substrate 5 and the board | substrate holding mechanism 79 which hold | maintains a board | substrate in the board | substrate table 78 is provided. In FIG. 16, a discharge dispenser is provided. In addition, the suction dispenser and the application dispenser can be installed and disassembled. The drive mechanism which supports the frame 84 at the main body side of the dispenser unit 400, and provided the ball screw (not shown) in the servomotor 75 so that the frame 84 can move to a board | substrate conveyance direction is provided. . The drive mechanism may be a linear motor system. The frame 84 includes a moving table 87 for holding the dispenser 83 to move in a direction perpendicular to the substrate conveyance direction, a servo motor 85 and a ball screw 86 for moving the moving table 87. A drive mechanism is formed. This drive mechanism may also be a linear motor. The moving table 87 is provided with a Z-axis driving mechanism 88 for moving the table 80 provided with the dispenser 83 up and down. Although not shown, the table 80 is provided with a camera for observing the alignment mark of the substrate and a distance sensor for measuring the distance between the substrate 5 and the dispenser 83. In the lower part of the unit, a control unit 70C for controlling each device in the unit is provided, and the control unit 70C can exchange signals with the control unit of the printing unit 200 or the inspection unit 300. Consists of.

1 is a diagram showing an example of a combination of each unit;

2 shows an example of a screen printing apparatus;

3 is a view for explaining the operation of the screen printing apparatus;

4 shows an example of an artificial model;

5 shows an example of a correlation map;

6 is a view showing an example of a result of searching for an arbitrary pattern of a substrate;

7 is a diagram showing an example of a processing flow in the correlation value calculation unit to the position coordinate calculation unit;

8 is a diagram illustrating an example of inspection and dimension correction after mark dimension measurement;

9 is a diagram showing an example of inspection and dimension correction after mark dimension measurement;

10 is a diagram illustrating an example of a processing flow in a dimension calculation unit and a dimension correction unit;

11 is a view showing an example of a composite metal squeegee,

12 is a view showing an example of printing using a composite metal squeegee,

13 is a view showing an equivalent spring system of the composite metal squeegee,

14 is a view showing an example in which a squeegee is formed of a steel spring;

15 is a cross-sectional view of the inspection unit,

16 is a perspective view of the dispenser unit.

Claims (9)

A solder paste printing system having a printing unit for applying solder paste on a substrate surface via a mask, the solder paste printing system comprising: Accumulation means for storing, accumulating and storing the elements caused by the occurrence of defects and processing methods for each element, and identifying and inspecting the state of the elements due to the occurrence of defects before printing the solder paste with the printing unit. Monitoring means, analytical means for judging and predicting whether or not each element is likely to cause defects, and analytical means capable of making quality forecasts and alarms to the operator based on the analysis results, and processing means for eliminating the causes of defects. Solder paste printing system comprising a. The method of claim 1, An inspection unit for inspecting the printing result after the solder paste printing in the printing unit, a communication means for communicating the information of the inspection result by the inspection means to the printing device, and analysis of the information of the inspection result by the inspection means And re-analyzing means for organizing and storing additional storage at any time as new knowledge of new defective cases. The method of claim 1, After the solder paste printing is performed by the printing unit, the solder paste is heated and cooled and soldered, and thereafter, an inspection unit for inspecting the appearance of soldering and communication means for communicating information of the inspection result by the inspection unit to the printing unit. And a reanalyzing means for analyzing information on the result of inspection by the inspection unit and reconstructing the storage means from time to time by storing and adding new defective cases as new knowledge. The method of claim 3, wherein A solder paste printing system comprising a plurality of dispenser units for partially applying solder paste or a plurality of rework units for correcting a defective solder part on a downstream side of the printing unit. The method of claim 4, wherein And the dispenser unit applies solder paste to the portion to repair the print-out portion when the inspection unit detects a print defect of the print-out. The method of claim 4, wherein When the inspection unit detects sagging of the solder paste or printing defects of bridges and smears, the substrate is conveyed to the dispenser unit including the suction dispenser among the plurality of dispenser units, and the excess solder paste is sucked therein. Solder paste printing system, characterized in that. The method of claim 4, wherein When the inspection unit detects a misalignment of printing, the solder paste printing is configured to transmit, from the inspection unit, the substrate and the positional information and the amount of misalignment in which the displacement occurs in the printing unit or the dispenser unit to the printing unit. system. The method of claim 4, wherein A solder paste printing system, wherein the dispenser of at least one of the plurality of dispenser units is configured to supply dissimilar materials other than solder paste such as an adhesive. The method of claim 1, The squeegee for pushing the solder paste into the substrate surface from the mask opening of the screen printing apparatus constituting the printing unit for printing the solder paste has a structure in which two or more spring constants including the leading end and the intermediate part have different parts. Solder paste printing system characterized by.

Images