KR20080102963A - Solder ball printer - Google Patents

Abstract

A solder ball printer including a flux printing part, a solder ball charge printing part, and an inspection repair part is provided to improve productivity by processing a flux bad printing early. A solder ball printer comprises the followings: a flux printing part printing a flux on an electrode pad of a substrate(21); a solder ball charge printing part supplying a solder ball on an electrode in which the flux is printed; an inspection repair part performing repair according to a failure state, and inspecting a print condition of the solder ball; and a camera(15) for inspecting observing a state of a screen(20) opening of the printing part after printing.

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 80-100 micrometers) of pitch 180-150 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 having a transfer pattern as an opening, a squeegee, a squeegee lifting mechanism and a horizontal moving mechanism, It is equipped with the control apparatus to control.

After bringing 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. The paste is filled, the table is lowered again, and the substrate and the screen are separated (the plate is separated), so that the paste is transferred onto the substrate, and then the substrate is removed from the apparatus for printing.

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 reflowed after mounting.

Moreover, according to patent document 1, there exists a method of filling a solder ball to a predetermined opening by rocking | swinging or vibrating a mask, or the method which consists of a process heated after filling by translational motion 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 collectively, so that the throughput is high and the manufacturing cost is low. However, the printing method is difficult to secure the uniformity of the transfer volume, presses the solder bumps after the reflow by the fluttering process, and smooths the height. Moreover, when fineness advances by 150-120 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 the robot by using a high precision solder ball suction jig, the tact in the case of pinning There is a problem of increasing the cost of bump formation due to the increase of the cost and the increase of the 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 and the static electricity by the van der Waals force between the particles with the small diameter of the solder ball particle diameter Adsorption phenomenon occurs and there is a problem 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 is a fear that a poor wetting may result in incomplete soldering.

An object of the present invention is to print bumps at a very high pitch, and to form a large amount of bumps in a batch like a printing method and to form bumps with a stable height like a solder ball injection method. The present invention provides a high productivity solder ball filling printing apparatus and a bump forming method that enable filling.

In order to achieve the above object, the present invention provides a flux printing unit for printing a flux on an electrode pad of a substrate, a solder ball filling / printing unit for supplying a solder ball on an electrode printed with the flux, and a solder ball. In a solder ball printing apparatus comprising an inspection / repair portion which inspects a state of a printed board and repairs in accordance with a defective state,

A flux printing unit comprising a screen provided with openings according to the positions of the plurality of electrode pads, a table on which the substrate is mounted and fixed, a positioning camera for imaging the positioning mark to align the substrate with the screen, Comparison between the inspection camera for observing the state of the screen opening after printing, the cleaning means for cleaning and removing the screen opening clogging or the flux contamination on the back surface of the screen, the image captured by the inspection camera, and the image of the reference model recorded in advance. Determination means for judging printing defects, and whether or not to send the substrate to the next step or to remove it from the line based on the determination result of the determination means, and if not, printing failure generating means for generating a cleaning instruction of the screen. It is.

In addition, a charging unit is provided in the print head attached to the solder ball filling / printing unit, and the filling unit is formed of a box body, a lid, and a sieve-shaped ball case, and a slit type at a distance from the sieve-shaped body at the lower part of the ball case. The upper body is installed, the cover is provided with a sheave shape through the support member, and the size of the opening provided in the sheave shape is varied so that the excitation means for supplying the solder ball to the slit shape is provided. It is.

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.

In addition, according to the present invention, the solder ball filling efficiency can be increased to allow tact shortening and high filling rate of the solder ball to be filled and printed, whereby productivity can be improved.

In addition, since the operation efficiency of each device from flux printing to solder ball filling to inspection and repair can be improved and the tact can be shortened, the solder bump height is high and the mass of a large amount of stable solder bumps is formed at low cost at high speed. It is possible to do In addition, the device also has a simple configuration, so that the equipment cost can be kept low.

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of the printing apparatus and bump formation method of this invention are described with reference to drawings.

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 screen 20 provided with an opening in accordance with the shape of the electrode pad 22, which is provided in advance in the substrate 21, and the squeegee 3 is moved, whereby the substrate 21 is moved. The predetermined amount of flux 23 is printed on the electrode pad 22 of ().

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.

In addition, during reflow, which is a subsequent step after solder ball printing, it causes solder wet failure and a solder bump having a clean shape cannot be formed, and solder bump height is poor and solder connection strength is insufficient. If the amount of the flux 23 is too large, the flux 23 may be used in openings provided in the screen 20 for supplying the solder ball 24 onto the electrode pad 22 at the time of filling and printing the solder ball. 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 of the screen and cannot be transferred onto the electrode pad 22. Thus, flux printing is a process having the most important factor in solder ball filling quality.

Next, as shown in FIG. 1B, the electrode pads 22 of the substrate 21 on which the flux 23 is printed in the solder ball filling / printing portion provided with the charging unit 60 (see FIG. 7). ), The solder ball 24 is filled and printed. The screen 20b for filling the solder ball 24 into the electrode pad 22 uses a metal screen manufactured by an additive method so as to ensure high-precision pattern position accuracy.

The material of the solder ball filling screen 20b is such that the gap between the substrate 21 and the screen 20 is such that the solder ball 24 is infiltrated between the substrate 21 and the screen 20 so as not to cause excessive ball failure. The magnetic material which enabled magnetic attraction by the magnet stage (printing table 10) which mounts a board | substrate so that it may become zero is used.

In addition, when the printed substrate 21 adheres closely to the back surface (the side in contact with the substrate 21) of the screen 20b, the bleeding of the flux 23 does not adhere around the screen opening. In order to prevent this, the micro support 20a made of resin or metal is provided. Thereby, the recessed part of the spreading of the flux 23 is comprised. In addition, the combination of the screen 20b and the support | pillar 20a is called the solder ball printing screen 20 hereafter.

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 20 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 20 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 20 is narrowed, the screen 20 is brought into contact with the substrate 21, and the charging unit 60 is operated to move the solder ball 24 to the screen 20. The flux 23 is supplied to the electrode pad 22 on the surface of the printed substrate 21 at the opening of the (). The slit-shaped body 63 is provided in the lower side of the solder ball supply charging unit 60 (refer FIG. 7), and it pushes and rotates the solder ball 24 by rocking and advancing the charging unit 60. As shown in FIG. Vibration is used to fill the solder balls 24 in the screen openings.

2 shows an embodiment of a solder ball printing apparatus. The apparatus shown in this figure is an apparatus which integrated the flux printing part, the solder ball filling and printing part, and the inspection and repair part. However, each part may be comprised as a single apparatus. In this apparatus, first, the flux 23 is printed on each electrode pad 22 on the substrate by the flux printing unit (screen printing method). Thereafter, the solder ball is supplied to the electrode pad via a conveyer conveyor (which is a conveyance conveyor on the flux printing unit side, and becomes a substrate loading conveyor when viewed from the solder ball filling / printing unit) through the flux at the solder ball filling / printing unit.

The difference between the flux printing portion and the solder ball filling / printing portion is a print head portion, the flux printing portion has a squeegee structure, and the solder ball filling / printing portion is composed of a filling unit for supplying solder balls. The inspection / repair portion has a dispenser suction / supply head structure of the print head portion. 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 (STEP 2). Next, the screen opening situation after flux printing is examined (STEP 3). In the case of NG by inspection, a board | substrate is carried out to the NG board | substrate stock part, and it cleans automatically with the board | substrate cleaning apparatus 45 (STEP 4). Thereafter, the flux is replenished as necessary.

Moreover, the board | substrate which became NG is discharged out of a line by waiting on the conveyor which is a subsequent process with NG signal so that the process after ball printing may not be performed. By using an in-line NG substrate stocker or the like, a magazine batch may be discharged. 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 state of solder ball filling into the screen opening from the top of the screen is inspected (STEP 6). As a result of the inspection, if there is a lack of filling, 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 state of charge is inspected by the inspection and repair apparatus after solder ball filling (STEP 9). In the case of the filling state inspection NG, after the flux supply, the solder balls are resupplied to the electrode pad portion at the NG point (STEP 10). If the state of charge inspection is OK, the solder balls are remelted in the reflow apparatus 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 printing 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 a flux printing part, the urethane squeegee 3 is attached to the printing head 2. In the case of the solder ball filling / printing portion, the filling unit 60 made of a slit-like body 63 or the like instead of the squeegee 3 is attached to the print head 2. 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 a substrate 21, which is a printing object, is provided so as to face the screen 20. The printing table 10 receives the 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. In addition, a table elevating mechanism 12 for bringing the substrate 21 closer to or in contact with the screen 20 surface is provided.

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 when printing is complete | finished, a board | substrate is received. The substrate 21 is discharged to the unloading 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 marks provided on each of the screen 20 and the substrate 21, performs image processing to obtain the amount of positional deviation, and corrects the amount of displacement. 11) 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, The data input unit 50 for rewriting control data, 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 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. I can easily select it.

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 unit 33 and the dimension calculation unit 34 are provided, and the position shift amount is determined based on the position recognition marks provided on the substrate 21 and the screen 20 from the data captured by the CCD camera 15 to stop. The XYθ table 11 is driven in accordance with the command of the XYθ table control unit to perform alignment.

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 and received 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 picks up the position recognition mark (not shown) provided in the board | substrate 21 and the screen 20, and transmits it to the printer control part 30. FIG. 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 printhead lifting mechanism 4 is operated to screen the squeegee (which shows the skid 3 in the drawing, but in the solder ball filling process, the slit-shaped body 63 at the tip of the filling unit 60). Touch the surface. Next, the screen surface is horizontally moved by rotationally driving the print head drive motor 2g while having the slit-shaped body 63, and is moved from the opening of the slit-shaped body 63 to the screen surface. The solder ball 24 is filled in the electrode pad 22 of the substrate 21.

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 mark alignment marks are provided on the substrate 21 and the screen 20 at the same portions. Each of the marks on both sides is recognized by the special CCD camera 15 having the vertical field of view of two, and the mark of the screen 20 is recognized from the bottom, the mark of the substrate 21 is recognized from the top, and is provided at a predetermined portion. All the position coordinates of the present mark are read out, the amount of displacement of the substrate 21 with respect to the screen 20 is calculated and corrected, and the substrate 21 is positioned with respect to the screen 20.

The opening state of the screen after printing a flux in FIG. 6 is shown. FIG. 6 (a) shows the state of the opening in which the shape of the entire screen is provided with one electrode group in FIG. 6 (b), and the state of the opening after printing the flux 23 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 ( By passing the substrate 21 and the screen 20 at the same time as the passage of 3), 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 screen printing flux 23, thixotropy, and the diameter of the opening 20k of the screen 20 is fine affects the situation of the opening 20k portion of the screen 20 after printing in a normal printing state. The flux 23 does not completely disappear from the inside of the opening, but a film is formed in a thin film.

If the opening 20k of the screen 20 is 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 where the screen opening is in a normal state, (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 determination of suitability of the opening state of the screen 20 is made 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. Next, 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 dimension calculation unit 34 It is judged 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) printing is completely uneven and looks uneven. 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 the remainder of a flux can be judged by the difference of the darkness of a color, it can determine easily by the comparison by the light grayscale model by image processing. Or it may determine by color difference comparison etc. using a color camera.

In addition, in order to confirm the situation of the opening part of the screen 20 with the positioning CCD camera 15, it illuminates upwards from the lower part of the screen 20, and is confirmed by the CCD camera arrange | positioned above the screen 20. The method can take a stable image. The method of illuminating downward from the top of the screen 20 may be taken. 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, adhesion contamination of the flux, etc., the printing apparatus according to the instruction of the printer control unit 30 Cleaning is performed automatically by the underplate cleaning apparatus 45 (refer FIG. 5) provided in the inside, 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 subsequent process by the instruction | command of the printer control part 30 with the NG signal so that the process after solder ball printing may not be performed. It is also good to discharge in a magazine batch by using an inline NG substrate stocker or the like. The NG substrate can be used for flux printing again after washing in an out-of-line process.

The structure of the solder ball printhead (charging unit 60) is shown in FIG. The charging unit 60 is spaced apart from the ball case housing the solder ball 24 in the 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 body 63 provided in this manner. 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 surface contact with the screen 20 may be carried out.

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 20 can be adjusted finely. The slit-like body 63 uses a magnetic material and has openings such as mesh-like openings or continuous rectangular slits so as to suit the diameter of the solder ball 24 as the target and the opening size of the screen 20. It is formed by a very thin metal plate.

FIG. 8 shows a horizontal vibrating mechanism for exciting the sheave body 62 provided in the ball case as the solder ball housing portion in the horizontal direction. 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 on the upper part of the cover 64. With this configuration, the sieve-shaped body 62 is excited by applying vibration by the excitation means 65 on the side of the ball case. 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 on the slit-shaped body 63 in the slit part of the sieve-shaped body 62. As shown in FIG. The amount of the solder ball 24 falling onto the slit-shaped body 63, that is, the supply amount of the solder ball 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. The compressed air flow rate may be varied or 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. Due to the dispersion effect, adjustment can be made in consideration of production efficiency so that the solder ball supply amount does not change due to the material of the solder ball 24 or the influence of 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 by the driving motor 68 to cause the slit-shaped body 63 to swing at an arbitrary stroke amount. Since the slit-shaped body 63 oscillates while being adsorbed to the screen 20 by magnetic force, there is no gap between the slit-shaped body 63 and the screen 20, so that the solder ball 24 is reliably fixed. It is possible to roll. In addition, the filling size of the slit-shaped body 63 makes it possible to efficiently fill the solder balls 24 to the openings of the slit-shaped body 63 and to perform the filling operation efficiently. The cycle speed of the screen 20 and the swinging motion can be arbitrarily varied by controlling the speed of the drive motor 68, and the charging 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 of the screen 20, and the cycling speed suitable for environmental conditions.

The figure of the structure which provided the spatula-shaped body in 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 20 is separated from the surface of the substrate 21, that is, the plate is separated to transfer the solder balls onto the substrate. When the solder ball 24 is left in the plate shape of the screen 20, the solder ball 24 falls onto the substrate 21 through the opening of the screen 20, causing the excessive solder ball to be defective. Becomes 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 in a state of high flatness accuracy, so that the solder ball 20 is not pushed out of the charging unit 60 in a state of being in close contact with the screen 20.

In addition, since the spatula 69 uses a magnetic material and is attracted to the screen 20 by magnetic force similarly to the slit-shaped body 63, the solder ball 24 is prevented from coming out of the charging unit 60. Can be. Moreover, you may comprise so that the spatula shape body 69 may be provided in the whole outer peripheral part area | region of a ball case.

The figure of the structure which attaches an air curtain to a charging unit part is shown in FIG. With the spatula 69, there can be almost no ball remaining on the plate surface of the screen 20. However, the influence of the ball rest due to the micro displacement of the plate surface of the screen 20 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 so that the air curtain may be formed around the charging unit. The jet port 75 is configured to supply compressed air from a compressed air supply source (not shown).

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

The figure explaining the state of charge inspection of the screen after solder ball printing is shown. 12 (a) and 12 (b) are the same as in Fig. 6, the description thereof is omitted here.

The state of solder ball filling with respect to the screen 20 after solder ball filling and printing is shown in (1)-(3) of FIG. The state in which the solder balls 24 are all filled in the opening of the screen 20 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 at the time of filling, 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 subsequent step, rejects are produced. Thus, by inspecting the filling state on the plate surface of the screen 20 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 it passes, the plate separating operation is performed to discharge the substrate 21 in a subsequent step.

13, the figure for demonstrating the repair operation in an inspection / repair part after solder ball filling is shown. The figure explaining the charging failure situation after solder ball filling is shown in FIG. As shown in Fig. 14, there are failure modes such as excess ball, in addition to ball failure, double ball, misaligned ball, and dent, as shown in Fig. 14.

In the inspection / repair portion, first, after the solder ball filling and printing is completed, the charging state on the substrate is confirmed by a CCD camera. If a defect is detected, the position coordinates of the defective portion are obtained. In the case of a defect such as a double ball, a misalignment ball, a dent, or an excess ball, the suction vacuum suction nozzle 86 is moved to the position of the solder ball, and the vacuum suction is carried out to a defective ball throwing station, Thereby, a waste box for dropping and discarding the ball is provided.

Moreover, when detecting the electrode head 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, and a flux is carried out. By dispensing the solder ball 24 in the flux 23 by moving the dispenser 87 in which the solder ball 24 is adsorbed to the flux 23 accumulated in the supply part 85, the flux in the solder ball 24 is maintained. (23) is added. The repair operation is completed by moving the dispenser 87 which adsorbs 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 addition, when the defective ball is removed from the crushed ball, the position shifting ball, or the like in the above-described inspection, it is possible to repair the defect by the above-described repair operation.

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.

The test | inspection board | substrate 82 on the carry-in side conveyor 88 is conveyed on the inspection part conveyor 90 in the arrow direction. A door frame 80 is provided at an upper portion of the inspection unit conveyor 90, and a line sensor (at a direction perpendicular to the substrate conveyance direction (marked direction) is provided on the carry-in side conveyor 88 side of the door frame 80. 81) is installed. 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 and the flux supply part 85 which accommodated the normal solder ball are provided in one 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. These vacuum suction nozzles 86 and the dispenser 87 are movable in the direction of the hatched arrow.

The inspection unit conveyor 90 is configured to be able to reciprocate in the direction of the arrow, and is configured to match the defect position to the dispenser or the vacuum suction nozzle position according to the defect position of the 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 which can accurately supply solder balls to electrode pad portions of a substrate and can prevent generation of defective products as much as possible.

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows the outline | summary of a flux printing and a solder ball filling and printing process,

2 is a view showing one example of a bump forming apparatus by solder ball printing;

3 is a flowchart of bump formation in the present embodiment;

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 a view showing an opening state of a screen after flux printing;

7 is a view showing the structure of a solder ball printhead,

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

9 is a view showing a horizontal swing mechanism of a solder ball printhead;

10 is a view for explaining a spatula shape for a solder ball printhead;

11 illustrates an air curtain for a solder ball printhead;

12 is a view for explaining a state example of a screen after solder ball printing;

13 is a diagram illustrating repair of a solder ball;

14 is a view explaining a shape of a solder ball printing defect;

It is a figure explaining the outline | summary of a test and repair apparatus.

※ Explanation of code for main part of drawing

1: printing press 2: printing head

3: squeegee 10: printing table

11: XYθ table 15: camera

20 screen 21 substrate

30: printer control unit 34: dimension calculation unit

45: cleaning device 60: charging unit

63: slit shaped body 65: excitation means

69: spatula

Claims (6)

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, Positioning camera which the said flux printing part picks up the positioning mark in order to perform the alignment of the board | substrate and the screen, the screen which mounts the said board | substrate, and mounts and fixes the said board | substrate according to the position of a some electrode pad. And an inspection camera for observing the state of the screen opening after printing, cleaning means for cleaning and removing the screen opening clogging or flux adherence to the back surface of the screen, an image captured by the inspection camera, and a previously recorded reference model. On the basis of the judgment result of the judgment means of comparing the images and the determination result of the judgment means, it is determined whether to send the substrate to the next step or to remove it from the line. A solder ball printing apparatus comprising a generating means. 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, The charging unit is attached to the print head attached to the solder ball filling / printing unit, The charging unit is provided with a ball case comprising a box body, a cover, and a sieve shape, and a slit-shaped body spaced apart from the sheave body at a lower portion of the ball case, and the sheave body through the support member on the cover. A solder ball printing apparatus comprising: an excitation means for supplying a solder ball to a slit-shaped body by varying the size of an opening provided in the sieve-shaped body with an excitation; The method of claim 2, A solder ball printing apparatus comprising a spatula shaped body made of a magnetic material around a ball case of the filling unit. The method of claim 3, wherein A solder ball printing apparatus according to claim 1, wherein a blowout port for compressed air for forming an air curtain around said ball case is provided. The method of claim 1, After the solder ball is supplied to the electrode pad on the substrate, the solder ball filling state checking means for inspecting and checking the solder ball filling and printing status of the screen openings is performed before the plate separating operation of the screen. Solder ball printing apparatus characterized in that installed. The method of claim 4, wherein Solder ball checking means for inspecting and checking the solder ball charge state of the inspection and repair portion, repair means for recharging the solder ball on the electrode pad without solder ball filling, and for solder balls and electrode pads outside the electrode pad. A solder ball printing apparatus, comprising: removing means for adsorbing and removing two or more existing solder balls or solder balls having a ball diameter larger or smaller than a predetermined size.

Images