KR20090082112A - Solder ball printer - Google Patents

Abstract

A soldering ball printing device capable of the forming bump of a bulk is provided to improve the productivity by processing flux bad printing which is the big factor of the soldering ball short shot is processed in the front process. A soldering ball printing device(101) is made of a flux printing unit, a soldering ball charge printing unit, and an inspection repair unit. Flux is printed the flux printing portion on the electrode pad of substrate. The soldering ball is supplied the soldering ball charge printing unit on the electrode in which flux is printed. The inspection repair unit inspects the state of the substrate in which the soldering ball is printed. The flux inspection repair unit is set up between the flux printing unit and the soldering ball charge printing unit. The flux inspection repair unit inspects the state of the substrate in which flux is printed. Repairs are performed according to the failure state. The soldering ball charge printing unit comprises screens and a printing unit.

Description

Solder Ball Printing Device {SOLDER BALL PRINTER}

TECHNICAL FIELD The present invention relates to a screen printing apparatus, and more particularly, to a solder ball printing apparatus for printing a solder ball on a substrate surface.

In ball bump formation (diameter 50-100 micrometers) of pitch of 100-180 micrometers, there exists a printing method which reflows cream solder after printing using a well-known high precision screen printing apparatus, and performs solder ball formation. As an example of a screen printing apparatus, a substrate loading conveyor, a substrate carrying conveyor, a table portion having a lifting mechanism, a squeegee head having a mask, a squeegee, a squeegee lifting mechanism, and a horizontal moving mechanism having a transfer pattern as an opening, It is equipped with the control apparatus to control.

After carrying in a board | substrate from an import conveyor part into a apparatus, the board | substrate is temporarily fixed to a printing table part, and then the mark of both the mask (screen) which has an opening corresponding to a board | substrate and a circuit pattern is moved with a camera. Recognize and correct the positional deviation of both sides, position the substrate on the screen, raise the printing table so that the substrate is in contact with the screen, and contact the substrate by the squeegee with cream solder or the like in the opening of the screen. Printing is performed by filling a paste, lowering a table again, separating a board | substrate and a screen (separating plate), and transferring a paste on a board | substrate, and then carrying out a board | substrate from an apparatus.

In addition, a ball injection method is known in which a solder ball is injected into a jig processed with high precision, aligned at a predetermined pitch, directly transferred onto a substrate, and formed into a solder ball by reflow after mounting.

Moreover, according to patent document 1, there exists a method which consists of the method of filling a solder ball in a predetermined opening by rocking | swinging or vibrating a mask, and the process of heating after filling by translational movement of a brush, etc. Moreover, according to patent document 2, there exists a method of putting a solder ball on a tray, adsorb | sucking with a tube, and recharging to an electrode pad.

[Patent Document 1]

Japanese Patent Application Laid-Open No. 2000-49183

[Patent Document 2]

JP 2003-309139 A

The printing method by cream solder is advantageous in that the equipment cost is low, and a large amount of bumps can be formed in a batch, so that the throughput is high and the manufacturing cost is low. However, in the printing method, it is difficult to secure uniformity of the transfer volume, and the solder bumps after the reflow are pressed to smooth the height by the fluttering process. Moreover, when fineness advances by 100-150 micrometer pitch etc. with the densification of an apparatus, there exists a point that print yield is bad and productivity is not good.

On the other hand, in the solder ball injection method, bumps having a stable height can be formed by securing the classification accuracy of the solder balls. However, since the solder balls are filled with a robot by using a high precision solder ball suction jig, they are collected in the case of being fined. There is a problem of increasing the cost of bump formation due to the increase of tact and the increase of jig and equipment price.

In addition, in the method of filling the solder ball in a predetermined opening by oscillating or vibrating the screen according to Patent Document 1, the adhesion phenomenon due to the van der Waals force between the particles due to the small hardening of the solder ball particle diameter, Adsorption by static electricity occurs and there is a problem in that the mask opening cannot be filled. Similarly, the same problem exists in filling by squeegee or brush translation.

Moreover, in the method of patent document 2, even if it can repair, when there is a possibility that the quantity of residual flux is very small, and the wettability of solder is bad at the time of batch reflow, even if a solder ball melts, There exists a possibility that the wetting defect which may become incomplete soldering may arise.

SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to inspect and repair the state of the flux after printing the flux so that a large amount of bumps can be formed in a batch as in the printing method, and a stable height such as the solder ball injection method can be obtained. It is to provide a solder ball filling printing apparatus capable of forming bumps having a high productivity and a very fine pitch that enables bump formation, and enables printing and charging at low cost and at high speed and efficiency.

In order to achieve the above object, the present invention provides a flux printing unit for printing flux on an electrode pad of a substrate, a solder ball filling / printing unit for supplying a solder ball on an electrode on which the flux is printed, and a solder ball. In a solder ball printing apparatus comprising an inspection / repair portion which inspects a state of a printed board and performs repairs according to a defective state, a state of a substrate on which a flux is printed is provided between the flux print portion and the solder ball filling / printing portion. A flux inspection / repair portion for inspecting and repairing according to a defective state, wherein the solder ball filling / printing portion has a screen for supplying solder balls to the substrate, and a slit-shaped body for filling solder balls into the screen. Characterized in that it comprises a printing means.

The solder ball filling / printing portion is provided with a magnetic screen having a magnetic printing table on which a substrate is mounted, an opening in contact with the substrate for supplying solder balls onto electrodes of the substrate, and an upper portion of the screen. And a printing means having the slit-shaped body made of metal arranged in the opening of the screen to fill the solder ball, wherein the magnetic attraction force of the printing table and the screen is greater than the magnetic attraction force of the screen and the slit-shaped body. Set.

The printing table has a neodymium magnet, the screen is made of nickel, and the slit-shaped body of the printing means is made of SUS304. The magnetic attraction force between the printing table and the screen was set to 10 to 100 gf / cm 2, and the magnetic attraction force between the screen and the slit-like body was set to 0.1 to 10 gf / cm 2.

The printing table is also equipped with a neodymium magnet having a surface magnetic flux density of 500 to 2000G.

ADVANTAGE OF THE INVENTION According to this invention, productivity can be improved by processing a flux printing defect which is a big factor of a solder ball filling defect early in a head process. Further, according to the present invention, the solder ball filling efficiency can be increased, and the solder ball filling and printing with a high tact shortening and filling rate can be performed, thereby improving productivity. In addition, since the operation efficiency of each device from flux printing to solder ball filling to inspection and repair can be increased, and the tact can be shortened, the solder bump height accuracy is good, and a large amount of stable solder bumps are collectively formed at low speed at high speed. It is possible to. In addition, the device also has a simple configuration, so that the cost of equipment can be kept low.

EMBODIMENT OF THE INVENTION Hereinafter, with reference to drawings, preferred embodiment of the printing apparatus and bump formation method of this invention are described. 1, the outline | summary of the printing process in a flux printing part and a solder ball filling and printing part is shown. Fig. 1 (a) shows the flux printing step, and (b) shows the state of solder ball filling and printing.

In Fig. 1 (a), the flux is placed on the flux printing screen 20 in which the opening is provided in accordance with the position and shape of the electrode pad 22 that is preliminarily installed on the substrate 21, and the squeegee 3 is moved. The predetermined amount of flux 23 is printed on the electrode pad 22 of the board | substrate 21 by this.

In the present embodiment, the screen 20 is a flux printing screen, and a metal screen manufactured by the additive method is used so as to ensure high-precision pattern position accuracy. As the squeegee 3, any one of square squeegee, gum squeegee or flat squeegee is used. The screen gap, phosphorous pressure, and squeegee speed according to the viscosity and thixotropy of the flux 23 are set, and a printing operation is performed. If the print amount of the flux 23 is too small, the solder ball cannot be attached onto the electrode pad 22 when the solder ball 24 is filled. Moreover, during reflow which is a post-process after solder ball printing, it becomes a cause of a solder wetting defect, and cannot form a solder bump of a clean shape, and also becomes a factor of a solder bump height defect and a solder connection strength shortage.

If the amount of the flux 23 is too large, the opening 20d provided in the screen 20b to be described later for supplying the solder ball 24 onto the electrode pad 22 at the time of filling and printing the solder ball. In some cases, the flux 23 may be attached. When the flux 23 is attached to the screen opening, a problem arises in that the solder ball 24 is attached to the opening 20d of the screen and cannot be transferred onto the electrode pad 22. Flux printing is thus a process having the most important factor in solder ball filling quality.

Next, as shown in Fig. 1 (b), the substrate 21 on which the flux 23 is printed in the main part of the solder ball filling / printing portion provided with the filling unit 60 (printing means) (see Fig. 7). The solder ball 24 is filled and printed on the electrode pad 22 of the electrode. In order to supply one solder ball 24 to each electrode pad 22, the screen 20b has an opening 20d, and the opening 20d is positioned on the electrode pad 22. Supply. Therefore, a metal screen manufactured by the additive method is used to ensure high-precision pattern position accuracy.

The substrate 21 is mounted so that the gap between the substrate 21 and the screen 20b becomes almost zero so that the solder ball 24 is infiltrated between the substrate 21 and the screen 20b to prevent excessive ball failure. Neodymium magnets are used for the printing table 10 (magnet stage), and nickel is used as the magnetic material so that the magnetic force from the printing table 10 is attracted to the material of the solder ball filling screen 20b.

Moreover, when the board | substrate 21 which completed printing the flux 23 adhere | attached on the back surface (side which contacts the board | substrate 21) of the screen 20b, the blur of the flux 23 peripheries the screen opening 20d. In order not to adhere to the film, a plurality of micro support pillars (post structures) 20a made of nickel are integrally formed with the screen 20b. Thereby, the recessed part of the spreading of the flux 23 is comprised. Moreover, even if this retreat part is comprised, the clearance between the board | substrate 21 and the back surface of the screen 20b becomes very small compared with the solder ball diameter by the magnetic adsorption force by the printing table 10, and the immersion of a solder ball is carried out. There is no proximity.

Moreover, in order to supply the solder ball 24 to the electrode pad 22 of a predetermined position with high precision, the positioning mark (not shown) is provided in four corners of the board | substrate 21. As shown in FIG. Corresponding to the positioning mark provided on the substrate 21 side, the positioning mark is also provided on the screen 20b side. These positioning marks are visually recognized by the CCD camera 15 (refer to FIG. 4), so that the positioning mark positions provided on the screen 20b side and the positioning mark positions on the substrate 21 side coincide with each other. Positioning is performed with high precision. In this embodiment, positioning is performed by moving the printing table 10 in which the board | substrate 21 is mounted in the horizontal direction.

When the alignment is completed, the distance between the substrate 21 and the screen 20b is narrowed, the screen 20b is brought into contact with the substrate 21, and the charging unit (printing means) 60 is operated so that the solder ball 24 ) Is filled in the opening 20d of the screen 20b, from which the flux 23 is supplied to the electrode pad 22 on the printed substrate 21 surface. The slit-shaped body 63 is provided in the lower side of the charging unit 60 (refer FIG. 7) for solder ball supply, and pushes and rolls the solder ball 24 by rocking and advancing the charging unit 60. As shown in FIG. Rotation and vibration are given to the opening 20d of the screen.

2, the process explanatory drawing of an Example of a solder ball printing apparatus is shown. The apparatus shown in this figure is the apparatus which integrated the flux printing part 101, the flux inspection / repair part 102, the solder ball filling-and-printing part 103, and the ball mounting inspection / repair part 104 integrally. However, you may comprise each said part as a single apparatus. Moreover, the structure which has the function of a flux test and repair according to ball mounting test and a repair part is also possible. In this apparatus, first, the flux 23 is printed on each electrode pad 22 on the substrate 21 by the flux printing unit (screen printing method) 101. Subsequently, the electrode pad 22 is passed through the screen 20b at the solder ball filling / printing portion 103 via a conveyer conveyor (a carrying conveyor on the slax printing portion side, and a substrate loading conveyor when viewed from the solder ball filling / printing portion). ), The solder ball 24 is supplied.

In addition, the part which differs greatly from the flux printing part 101 and the solder ball filling and printing part 103 is a print head part, the flux printing part 101 is a squeegee structure, and the solder ball filling and printing part 103 is solder | pewter. It is comprised by the charging unit 60 for supplying a ball. In the inspection and repair portions 102 and 104, the print head portion has a dispenser suction / supply head structure. In addition, since the screen does not need to be used in the inspection / repair portion, the plate frame holder for screen installation is not provided.

3, the flowchart of bump formation in a present Example is shown. After the substrate loading (STEP 1), a predetermined amount of flux is printed on the electrode pad 22 (STEP 2). Next, the electrode pad surface state after flux printing is examined (STEP 3). In the case of NG (defective) by inspection, the flux is resupplied to the NG portion to be repaired, and the NG information is fed back to the flux printing unit 101, and the screen cleaning device 45 is automatically cleaned by the under plate cleaning device 45. (STEP 4).

The substrate which became NG can also be discharged out of the line by waiting on the conveyor of a post process with an NG signal so that a process after ball printing may not be performed. By using an inline NG substrate stocker or the like, a magazine may be configured to be discharged in a batch. The NG substrate can be used for flux printing again after washing in an out-of-line process.

Next, solder ball filling and printing are performed (STEP 5). After solder ball filling and printing, the solder ball filling condition from the top of the screen to the screen opening is examined before the plate is separated (STEP 6). As a result of the inspection, if there is a insufficient charge, the solder ball filling and printing operation is performed again before the plate is separated (STEP 7). As a result, the solder ball filling rate can be improved.

When OK in STEP 6, remove the plate (STEP 8). Next, the inspection and repair apparatus 104 after the solder ball filling is inspected for the filling state (STEP 9). In the case of the filling state inspection NG, after supplying the flux, the solder balls are supplied again to the electrode pad portion at the NG point (STEP10). If the state of charge inspection is OK, the solder balls are remelted with a reflow apparatus (not shown) to complete the solder bumps.

4, the schematic structure of the screen printing apparatus (mainly flux printing part) in this invention is shown. The configuration seen from the front of the screen printing apparatus in FIG. 4A and the system configuration diagram in FIG. 5 (a) and 5 (b) show a diagram for explaining the operation of the screen printing apparatus.

The main frame 1 is provided with a plate frame holder (not shown), and the plate frame holder is configured such that a mask having a screen 20 having a print pattern as an opening to the plate frame 20c (see FIG. 6) is set. It is. In this figure, the print head 2 provided with the squeegee 3 is arrange | positioned above the screen 20. As shown in FIG.

In the case of the flux printing part 101, the urethane squeegee 3 is attached to the printing head 2. In the case of the solder ball filling / printing part 103, a filling unit (printing means) 60 composed of a slit-like body 63 or the like is attached to the print head 2 instead of the squeegee 3. The print head 2 is configured to be movable in the horizontal direction by the print head moving mechanism 6 and up and down by the print head lifting mechanism 4. By replacing the squeegee 3 with the filling unit 60, the filling unit 60 can be moved up and down by the print head lifting mechanism 4.

Below the screen 20, a printing table 10 for mounting and holding the substrate 21, which is a printing object, is provided to face the screen 20. The printing table 10 includes an XYθ table 11 for moving the substrate 21 in the horizontal direction (XYθ direction) to position the screen 20 and the substrate 21 from the loading conveyor 25. A table lifting mechanism 12 is provided for receiving and bringing the substrate 21 closer to or in contact with the surface of the screen 20.

The substrate receiving conveyor 26 is provided in the upper surface of the printing table 10, and the board | substrate 21 carried in by the board | substrate loading conveyor 25 is received on the printing table 10, and a board is carried out when printing is complete | finished. The substrate 21 is discharged to the conveyor 27.

The screen printing apparatus has a function of automatically aligning the screen 20 with the substrate 21. That is, the CCD camera 15 picks up the alignment mark provided on each of the screen 20 and the board | substrate 21, image-processes, calculates the position shift amount, and corrects the shift amount. (11) is driven to perform alignment.

Moreover, the printing control part 30 provided with the printing control part 36 which consists of the plate separation control part 39, the drive control part of each part, etc., and the image input part 37 which processes the image signal from the CCD camera 15, A data input unit 50 for rewriting control data, changing a printing condition, or the like, and a display unit 40 for monitoring the printing status or the like and the introduced recognition mark are provided inside the main body frame of the printer. It is placed outside.

The printer control unit 30 has a printing control unit 36 that controls the charging unit 60, and selects an appropriate charging / printing mode according to the pitch of the produced bumps, the difference in the solder ball particle diameter, and the type of metal mask to be used. You can easily select and set.

Moreover, the correlation value calculation part 31 which calculates a correlation value according to an input image, the shape estimation part 32 which calculates | requires a shape based on the image from the image or the dictionary 38 which were introduced, and the position coordinate which calculates a position coordinate The calculation part 33 and the dimension calculation part 34 are equipped, and the position shift amount is based on the position recognition mark provided in the board | substrate 21 and the screen 20 from the data imaged by the CCD camera 15. FIG. It calculates | requires and arrange | positions by driving the XY (theta) table 11 based on the command of an XY (theta) table control part.

Next, the operation of the printing apparatus will be described taking the solder ball filling and printing section as an example. The substrate 21 on which the solder bumps are formed is supplied to the substrate receiving conveyor 26 by the substrate loading conveyor 25. When the board | substrate 21 is conveyed to the position of the printing table 10, the board | substrate 21 is exchanged on the printing table 10 from the board | substrate receiving conveyor 26 by raising the printing table 10. FIG. The board | substrate 21 exchanged with the printing table 10 is fixed to the predetermined position of the printing table 10. FIG. After fixing the board | substrate 21, the CCD camera 15 is moved to the board | substrate mark position preset. The situation is shown in Fig. 5A.

Subsequently, the CCD camera 15 captures a position recognition mark (not shown) provided on the substrate 21 and the screen 20, and transfers it to the printer control unit 30. The image input unit 37 in the printer control unit obtains the positional displacement amount between the screen 20 and the substrate 21 from the image data, and based on the result, the printer control unit 30 moves the print table 10 in the XYθ table. The control unit 35 is operated to correct and position the position of the substrate 21 with respect to the screen 20.

The situation after completion of the alignment operation is shown in Fig. 5B. First, the CCD camera 15 operates to retract a predetermined amount to a position where the CCD camera 15 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 21 into contact with the mask 20. In this state, the print head lifting mechanism 4 is operated so that the squeegee (which shows the squeegee 3 in the drawing, but becomes the slit-shaped body 63 at the tip of the filling unit 60 in the solder ball filling process) is screened. Contact with. Next, the screen surface is horizontally moved by rotationally driving the motor 2g for driving the print head while the slit-shaped body 63 is moved and swinged, and the screen surface is opened from the opening of the slit-shaped body 63. The solder ball 24 is filled into the electrode pad 22 of the substrate 21 via the opening provided in the.

The print head 2 is raised after a predetermined distance stroke in the horizontal direction. Then, the printing table 10 is lowered, the screen 20 and the substrate 21 are separated, and the solder balls 24 filled in the openings of the screen 20 are transferred to the substrate 21. Then, the substrate 21 on which the solder balls 24 are printed is sent to the next step via the substrate transport conveyor 27.

As described above, two or more recognition position alignment marks are provided on the substrate 21 and the screen 20 at the same portions. Each of these marks is recognized by the special CCD camera 15 having up and down two views, and the mark of the screen 20 is recognized from below, and the mark of the substrate 21 is recognized from above, and installed in a predetermined portion. All the position coordinates of the marked marks are read, the positional calculation and correction of the shift amount of the substrate 21 with respect to the screen 20 are performed, and the substrate 21 is positioned with respect to the screen 20.

6 shows the opening state of the screen after printing the flux. FIG. 6 (a) shows the state of the opening after the shape of the entire screen is provided with one electrode group in FIG. 6 (b), and the state of the opening after the flux 23 is printed in FIG. 6 (c). have. The opening state of the normal screen 20 after the printing of the flux 23 is shown in Fig. 6C. By setting the appropriate screen gap (gap between the screen and the substrate), the pressure (the pressing force against the screen of the squeegee) and the squeegee speed, the flux 23 is sufficiently filled in the opening 20k of the screen 20 and the squeegee 3 When the substrate 21 and the screen 20 are plate-separated at the same time as the passage of the cross-section), the flux 23 can be reliably transferred to the electrode pad 22 of the substrate 21. In addition, the screen 20 is fixed to the plate frame 20c.

The fact that the viscosity of the flux 23 for screen printing, thixotropy, and the diameter of the opening 20k of the screen 20 is fine is affected, and the situation of the opening 20k of the screen 20 after printing is a normal printing state. In this case, the flux 23 does not completely disappear from the inside of the opening, and a thin film is formed.

If the openings 20k of the screen 20 are clogged or the plate separation or transferability deteriorates due to factors such as bleeding, scattering and drying of the flux 23, the printing result is uneven. The printing state can be judged by checking the printing screen 20 without checking the substrate 21. (C) of FIG. 6 (c) shows a state in which the screen opening is normal, (2) shows a state of partially clogging, and (3) shows a state of clogging as a whole. In the portion where the transfer amount to the substrate side is large, the residual amount of flux to the opening side of the screen is small, and on the contrary, in the portion where the transfer amount to the substrate side is small, the residual amount of flux to the opening side of the screen increases. That is, the state which reversed the printing state to the board | substrate 21 can be observed from the screen 20 side.

The pass / fail determination of the opening state of the screen 20 is performed as follows. The opening state of the screen 20 is picked up by the CCD camera 15, and the picked-up image is introduced into the printer control unit 30 via the image input unit 37. Subsequently, the image of the reference model of the opening state of the screen 20 previously stored in the dictionary 38 and the image of the opening state of the screen 20 introduced above are compared, and the size calculation section 34 It is determined whether it is "normal" or "bad NG." As a result of the determination, "normal" indicates a state where the screen opening is normal, and "defect NG" indicates a state where the screen opening partially clogs or a state that causes clogging as a whole.

After printing the flux, the opening state of the screen 20 determined as defective NG is shown in (2) and (3) of Fig. 6C. (2) is completely uneven printing, and the shape looks stained. This detection can be easily performed by pattern matching by a monochrome camera.

On the other hand, in the case of NG as in (3), the flux 23 is not printed on the substrate 21 but remains in the opening 20k portion of the screen 20 much. For this reason, since the grade of flux remainder can be judged by the difference of the density of a color, it can determine easily by the comparison by the light gray scale model by image processing. Or you may determine by color difference comparison etc. using a color camera.

In addition, in order to confirm the situation of the opening of the screen 20 with the positioning CCD camera 15, it illuminates upward from the lower part of the screen 20, and confirms with the CCD camera arrange | positioned above the screen 20. How to get a stable image. A method of illuminating downward from the top of the screen 20 may be employed. Since the CCD camera 15 has a camera (imaging) up and down, when used as a positioning camera for picking up positioning marks, up and down cameras are used, and the situation of the opening of the screen 20 after printing is observed. When used as a camera for inspection, the upper camera is used.

After the inspection of the state of the screen 20, when the inspection result is triggered by the dimension calculation unit 34, such as clogging of the screen opening, contamination of the adhesion of the flux, etc., the instruction of the printer control unit 30 Thereby, cleaning is performed automatically by the underplate cleaning apparatus 45 (refer to FIG. 5) provided in the printing apparatus, and the flux 23 is supplied and replenished as needed. Moreover, the board | substrate which became NG is discharged out of a line by waiting on the conveyor of a post process according to the command of the printer control part 30 with the NG signal so that the process after solder ball printing may not be performed. By using an inline NG substrate stocker or the like, it may be discharged in a magazine batch. The NG substrate can be used for flux printing again after washing in an out-of-line process.

Next, a method of inspecting a pad surface by a camera using inner diameter illumination in FIG. 7 will be described. The flux 23 printed and transferred to the electrode pad 22 is difficult to identify the presence or absence of the flux 23 because the illumination light easily passes through the flux 23 in the microscope observation by the reflection light method. When the diameter of the transferred flux 23 is larger than the diameter of the electrode pad 22 or when the transfer position shift occurs and is transferred out of the electrode pad 22, the presence or absence of the flux 23 is determined by microscopic observation in the reflected light method. Although it is possible to discriminate, it is difficult to discriminate the presence or absence of the flux 23 formed on the electrode pad 22, and therefore it is not possible to determine whether the transfer area is appropriate.

Therefore, as shown in the lowermost figure of FIG. 7, when the inspection method by the CCD camera 15 using the inner diameter side illumination 15L is used, the flux 23 of the flux 23 is transferred from the upper side with respect to the transferred flux 23. FIG. By the illumination reaching the outer diameter direction, the flux 23 can be discriminated by the effect of floating the subject. As for the automatic inspection, as described above, the illumination provided to the CCD camera 15 can be coped by switching from the downward illumination to the inner diameter illumination 15L.

In addition, by using the position measuring mechanism vertically and vertically in combination with the electrode pad 22 in the CCD camera 15 having the inner diameter illumination, by measuring the positional relationship between the vertex portion and the bottom portion of the flux 23, The height of the flux 23 and the amount of the flux 23 can be measured.

When the wavelength of the illumination used is blue light having a wavelength closer to the ultraviolet region in the visible light region, the discrimination is improved.

In addition, by containing the fluorescent material in the flux 23 and observing the printing result with illumination having a wavelength in the ultraviolet region, the flux 23 can be easily distinguished by the light from the fluorescent material contained in the flux 23. Become.

8 shows the structure of a solder ball print head (printing means, filling unit 60). The filling unit 60 has a ball case housing the solder balls 24 in a space formed by the box body 61, the lid 64, and the sheave body 62, and the sheave body 62. It consists of the slit-shaped bodies 63 provided at intervals. The sheave body 62 is formed of a very thin metal plate having an opening such as a mesh opening or a continuous rectangular slit so as to fit the diameter of the solder ball 24 to be supplied. The slit-shaped body 63 is arrange | positioned under the sheave-shaped body 62, and the slit-shaped body 63 is comprised so that it may surface-contact with the screen 20b.

By the printhead lifting mechanism 4 without description in this figure, the contact degree and gap of the slit-shaped body 63 with respect to the screen 20b can be adjusted finely. The slit-shaped body 63 uses a magnetic material and forms openings such as mesh-like openings or continuous rectangular slits so as to fit the diameter of the target solder ball 24 and the opening dimensions of the screen 20. The branches are formed of very thin metal plates.

The screen 20b is formed of a sheet made of neodymium in which the screen having the support pillar (post structure) 20a and the support pillar are integrally formed of nickel, and the surface magnetic flux density is 500 to 2000 G in the substrate mounting portion. The printing table 10 in which the magnet was installed is provided. And by setting the adsorption force by the magnetic force of the screen 20b and the printing table 10 to 10-100 gf / cm <2>, it is possible to make the surface of the board | substrate 21 and the screen 20b adjoin so that the clearance gap beyond a solder ball diameter may not arise. Become. If the adsorption force is too weak, a gap is formed in the lower part of the screen 20b and the surface of the substrate 21, so that the solder ball 24 enters and becomes a defective factor.

When the substrate 21 is separated from the screen 20b after the end of printing, by controlling the descending speed and acceleration of the printing table 10, the operation of detaching the screen 20b is performed to flow toward the center around the substrate. By uniform load, uniform plate separation can be performed. However, if the adsorption force by the magnetic force is too strong with respect to the tension of the screen, it becomes impossible to control.

In addition, the printing table in which the self-adsorption force of the slit-shaped body 63 and the screen 20b of the printing means (charging unit) 60 is provided with a neodymium sheet magnet 10S having a surface magnetic flux density of 500 to 2000G. By (10), it is set so that it may become 0.1-10 gf / cm <2>. The slit-shaped body 63 with respect to the solder ball on a screen by making the slit-shaped body 63 for printing which comprises the printing means (filling unit) 60, and the slit-shaped body for ball collection | recovery made of SUS304, and making a screen nickel. By maintaining the microball in the slit-shaped body 63 by uniformly softly acting in the vertical direction with the screen 20b by the magnetic force generated in the printing table 10, the ball does not cause deformation damage to the ball. Thus, the operation for filling the opening 20d of the screen can be efficiently performed.

9 shows a horizontal vibrating mechanism having the sheave body 62 provided in the ball case 61, which is the solder ball housing portion of the printing means, in the horizontal direction. In the upper part of the lid 64, it was set as the structure which provided the support member 70 which provided the excitation means 65 in the position parallel to the ball case side surface. With this configuration, the excitation is carried out by the excitation means 65 on the side of the ball case, so as to excite the sieve-like body 62. By vibrating the sheave body 62, the slit-shaped opening provided in the sheave body 62 can be opened larger than the diameter of the solder ball 24.

Thereby, the solder ball 24 accommodated in the ball case falls from the slit part of the sieve-shaped body 62 on the slit-shaped body 63. As shown in FIG. The amount of the solder balls 24 falling onto the slit-shaped body 63, that is, the supply amount of the solder balls 24 can be adjusted by varying the excitation energy by the excitation means 65.

The vibration means 65 shown in this figure can control the frequency by fine-adjusting the compressed air pressure by digital control using an air rotary vibrator. By varying the compressed air flow rate, the frequency may be varied. In addition, the sieve-shaped body 62 and the ball case are vibrated by the excitation means 65 to the solder balls 24 housed in the ball case, and are caused by van der Waals forces acting between the solder balls 24. The attraction force is offset and dispersed. The dispersion effect enables adjustment in consideration of production efficiency so that the solder ball supply amount does not change under the influence of the material of the solder ball 24 or the temperature and humidity in the production environment.

9 shows the horizontal swing mechanism of the charging unit 60. The slit-shaped body 63 is formed using a magnetic material. By using the magnetic material, the slit-shaped body 63 can be adsorbed to the screen 20 formed of the magnetic material by the magnetic force from the magnet built-in stage (printing table 10). As shown in FIG. 9, the horizontal rocking mechanism is comprised as follows. The linear guide 67 is installed on the upper portion of the supporting member 70, and the charging unit supporting member 71 is provided with a linear rail so that the linear guide 67 can be moved. The charging unit support member 71 is provided with a drive motor 68, an eccentric cam 66 provided on the drive motor shaft, and the support member is rotated in the horizontal direction by rotating the eccentric cam 66. It is configured to move to.

That is, the horizontal rocking mechanism in the horizontal direction rotates the eccentric cam 66 by the drive motor 68 to cause the rocking motion to the slit-shaped body 63 at an arbitrary stroke amount. . Since the slit-shaped body 63 oscillates while being adsorbed to the screen 20b by magnetic force, the solder ball 24 is reliably prevented from forming a gap between the slit-shaped body 63 and the screen 20b. It is possible to roll. In addition, the filling size of the slit-shaped body 63 makes it possible to reliably replenish the solder ball 24 to the opening 20d of the slit-shaped body 63, thereby enabling efficient filling operation. The cycle speed of the screen 20 and the swinging motion can be arbitrarily varied by speed limiting the drive motor 68, and the filling tact of the solder ball 24 in consideration of the line balance can be set. Moreover, the filling rate was controllable by adjusting the kind of material of the solder ball 24, the opening part 20d of the screen 20b, and the cycling speed suitable for environmental conditions.

The figure of the structure which attached the spatula-shaped body (solder ball collection | recovery means) to the filling head is shown in FIG. After supplying the solder balls 24 onto the substrate 21 by the charging unit 60, when the screen 20b is detached from the surface of the substrate 21, that is, plate separation is performed on the substrate 21. If the solder ball 24 remains in the plate shape of the screen 20b when transferring the solder ball, the solder ball 24 falls onto the substrate 21 through the opening of the screen 20b, and the excess solder ball May cause a defect. Therefore, in this embodiment, the spatula 69 is provided at approximately the same height as the slit-shaped body 63 at intervals with respect to the ball case in the advancing direction of the charging unit 60. The tip of the spatula 69 is very thin and polished with high flatness accuracy, so that the solder ball 24 is not pushed out of the charging unit 60 in a state of being in close contact with the screen 20b. In this way, the spatula 69 makes it possible to recover the excess solder balls.

In addition, since the spatula 69 is attracted to the screen 20b by magnetic force similarly to the slit-shaped body 63 when the magnetic material is used, the solder ball 24 does not come out of the charging unit 60 outside. can do. Moreover, you may comprise so that the spatula 69 may be installed in the whole area | region of the outer peripheral part of the ball case 61. As shown in FIG.

In addition, the spatula 69 is formed of a porous chamber foam having a hole sufficiently larger than the solder ball diameter, so that printing can be performed while efficiently replenishing the solder ball 24.

12, the figure of the structure which attaches an air curtain to the charging unit 60 is shown. With the spatula 69, there can be almost no ball remaining on the plate surface of the screen 20b, but the influence of ball remaining due to the micro displacement of the plate surface of the screen 20b can be considered. Therefore, in this embodiment, in order to zero the defect by excess solder balls, an air curtain is provided. That is, the air blower outlet 75 is provided in the motor support member which supports the head lifting mechanism (up-and-down motor) 4 which comprises the printing head 2, and it forms an air curtain around a charging unit. The jet port 75 is configured to supply compressed air from a compressed air supply source (not shown).

By the air curtain, the ball pushed out by the compressed air when the charging unit moves in the direction of the end surface of the substrate is pushed toward the charging unit operation direction side so that no ball remains on the plate surface.

The figure explaining the state of charge inspection of the screen after solder ball printing is shown. 13 (a) and 13 (b) are the same as in FIG. 6, the description thereof is omitted here.

The solder ball charging state with respect to the screen 20b after solder ball filling and printing is shown to (1)-(3) of FIG. 13 (c). The state where all the solder balls 24 were filled in the opening of the screen 20b can be observed as shown in (1). (2) shows a state in which solder ball filling is incomplete. (3) shows a double ball state in which a plurality of solder balls 24 are adsorbed upon charging and a state in which excess solder balls remain on the plate surface of the screen.

The plate is separated in the state of (2) and (3), and even if the substrate is flown in a later step, rejected products are produced. Therefore, by inspecting the filling situation on the plate surface of the screen 20b before performing the plate separating operation, it is possible to correct the rejected product to good quality by retrying the filling / printing operation by the charging unit 60. This detection can be determined by pattern matching comparing with a good model. After filling and printing the solder ball, the line sensor camera installed on the print head side performs collective recognition in units of areas. If it is NG, solder ball filling and printing are executed again. If passed, the plate separating operation is performed to discharge the substrate 21 in a later step.

14, the figure for demonstrating the repair operation | work in an inspection / repair part after solder ball filling is shown. FIG. 15 is a view for explaining a charging failure situation after solder ball filling. As shown in Fig. 15, there are failure modes such as excess balls, in addition to ball failure, double ball, displaced ball, and dents, in solder ball filling failure.

In the inspection / repair unit, first, after the solder ball filling and printing is completed, the charging state on the substrate is confirmed by a CCD camera. And if a defect is detected, the position coordinate of a defective part is calculated | required. In addition to double balls, misplaced balls, and dents, such as excessive balls, the suction vacuum suction nozzle 86 is moved to the position of the solder ball, and the vacuum suction is carried out to the defective ball disposal station. Thereby, a waste box for dropping and discarding the ball is provided.

Moreover, when detecting the electrode pad part which is not supplied due to the short supply of the solder ball 24, the normal solder ball 24 accommodated in the solder ball accommodating part 84 is attracted by the dispenser 87, The solder ball 24 is moved by moving the dispenser 87 in which the solder ball 24 is adsorbed to the flux 23 accumulated in the flux supply part 85 and immersing the solder ball 24 in the flux 23. To the flux 23 is added. The repair operation is completed by moving the dispenser 87 which adsorbed the solder ball 24 to which the flux 23 is added, to the defect part of a board | substrate, and supplying a solder ball to a defect part.

In the above inspection, when the defective ball is removed from the crushed ball, the out of position ball, or the like, the defect can be repaired by the repair operation described above.

The figure explaining the schematic structure of a test | inspection repair apparatus is shown in FIG. In addition, in this figure, a test | inspection repair part is shown as one independent apparatus.

표 방향으로 반송되어 온다. 검사부 컨베이어(90)의 상부에는 도어형 프레임(80)이 설치되어 있고, 도어형 프레임(80)의 반입측 컨베이어(88) 측에는 기판반송방향(

표 방향)에 대하여 직각방향으로 라인센서(81)가 설치되어 있다. 이 라인센서(81)에 의하여 기판(21) 상의 전극 패드(22)에 인쇄한 땜납볼(24)의 상태를 검출하도록 하고 있다. The inspection target substrate 82 is placed on the inspection side conveyor 90 on the carry-in side conveyor 88.

It is conveyed in the table direction. The door frame 80 is installed on the upper part of the inspection unit conveyor 90, and the substrate conveyance direction (

The line sensor 81 is provided in the direction perpendicular to the table direction). The line sensor 81 detects the state of the solder ball 24 printed on the electrode pad 22 on the substrate 21.

Moreover, the solder ball accommodating part 84 which accommodated the normal solder ball, and the flux supply part 85 are provided in the leg side which supports the door frame 80. As shown in FIG. The waste box is provided on the other leg side. The door-shaped frame portion is provided with a vacuum suction nozzle 86 for suction-removing defective solder balls and a dispenser 87 for repairing defects on a substrate so as to be movable left and right by a linear motor. As a result, the vacuum suction nozzle 86 and the dispenser 87 can move in the direction of the hatched arrow.

표 방향으로 왕복 이동할 수 있도록 구성되어 있어, 기판의 결함 위치에 따라 디스펜서나 진공 흡착 노즐 위치에 결함 위치를 맞출 수 있도록 구성되어 있다. 또 검사·리페어가 종료된 기판은 반출 컨베이어(89)에 의하여 반출되고, 리플로우장치에 보내진다. 상기한 구성으로 함으로써, 도 14에서 설명한 동작으로 검사 리페어를 행하는 것이 가능해진다. Inspection unit conveyor 90

It is comprised so that reciprocation may be performed in a table direction, and it is comprised so that a defect position may be matched with a dispenser or a vacuum suction nozzle position according to the defect position of a board | substrate. Moreover, the board | substrate with which inspection and repair was completed is carried out by the carrying-out conveyor 89, and is sent to a reflow apparatus. With the above configuration, the inspection repair can be performed by the operation described with reference to FIG. 14.

As described above, it is possible to realize a printing apparatus capable of supplying the solder balls accurately to the electrode pad portions of the substrate and positively preventing the occurrence of defective products.

1 is a schematic diagram of a flux printing and solder ball filling / printing process of an embodiment of the present invention;

2 is a process explanatory diagram of a solder ball printing apparatus,

3 is a flowchart of bump formation;

4 is a diagram showing a schematic configuration of a screen printing apparatus;

5 is an operation explanatory diagram of a screen printing apparatus;

6 is an explanatory diagram of an outline of an inspection / repair apparatus after flux printing;

7 is an explanatory diagram of a pad surface inspection method using a camera using inner diameter illumination;

8 shows the structure of a solder ball print head,

9 is a view showing a horizontal vibrating mechanism for the solder ball housing portion sheave shape;

10 shows a horizontal vibrating mechanism of the solder ball print head;

11 is an explanatory diagram of a spatula shape body for a solder ball print head,

12 is an explanatory diagram of an air curtain for a solder ball print head;

13 is an explanatory diagram of a state example of a screen after solder ball printing;

14 is an explanatory diagram of a repair of a solder ball;

15 is an explanatory diagram of a shape of a solder ball printing defect;

16 is an explanatory diagram of an outline of an inspection and repair apparatus.

※ Explanation of code for main part of drawing

1: printing machine 2: printing head

3: squeegee 10, 10b: printing table

10s: neodymium magnet 11: XYθ table

15: Camera 20, 20b: Screen

20a: support pillar 20d: opening

21: substrate 30: printing machine control

34: dimension calculation part 45: cleaning device

60: printing means (charging unit) 63: slit-shaped body

65: excitation means 69: spatula

101: Flux printing part 102: Flux inspection and repair part

103 solder ball filling and printing section 104 inspection and repair section

Claims (5)

The flux printing unit for printing the flux on the electrode pad of the substrate, the solder ball filling / printing unit for supplying the solder ball on the electrode on which the flux is printed, and the state of the substrate on which the solder ball is printed are inspected. In the solder ball printing apparatus comprising an inspection and repair portion for repairing according to the present invention, Between the flux printing section and the solder ball filling / printing section, a flux inspection / repair section for inspecting the state of the substrate on which the flux is printed and performing repairs in accordance with a defective state is provided, and the solder ball filling / printing section includes the And a printing means having a screen for supplying solder balls to a substrate and a slit-shaped body for filling the screen with solder balls. The method of claim 1, The solder ball filling / printing portion is disposed above the screen and is made of a metal screen having a magnetic printing table on which a substrate is mounted, an opening for contacting the substrate and supplying solder balls onto an electrode of the substrate. Printing means having the slit-shaped body made of metal filling the solder ball in the opening of the screen, wherein the magnetic attraction force of the printing table and the screen is set to be greater than the magnetic attraction force of the screen and the slit-shaped body. Solder ball printing device characterized in that. The method of claim 2, And the printing table has a neodymium magnet, the screen is made of nickel, and the slit-shaped body of the printing means is made of SUS304. The method of claim 2 or 3, The magnetic attraction force of the printing table and the screen is set to 10 to 100 gf / cm2, and the magnetic attraction force of the screen and the slit-shaped body is set to 0.1 to 10 gf / cm2. The method according to any one of claims 2 to 4, And a neodymium magnet having a surface magnetic flux density of 500 to 2000G.

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