JP2006286989A - Printing method and system thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing method and a system thereof capable of adjusting a tact time between a printing process and a subsequent process so that an increase in temporarily storing quantity of a substrate after printing can be reduced, and preventing defective printing when an elapsed time from cleaning a printing member for a printer becomes long. <P>SOLUTION: In a printing process, printing processing interval per substrate is switched depending on an elapsed time after cleaning from the finishing time of cleaning of a printed member. In a substrate carrying process, a substrate after printing is carried out in response to a processing start time in a component mounting process as a subsequent process. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a printing method and a system for printing a conductive printing agent on a substrate such as a printed circuit board.

  2. Description of the Related Art In recent years, attention has been paid to a method of directly mounting a bare chip component, which is a bare semiconductor chip before sealing with a resin, on a substrate as a mounting method of a substrate used in electronic devices that are significantly reduced in size and weight. Conventionally, as a method of manufacturing a substrate on which this kind of bare chip component is mounted, a cream solder which is a conductive printing agent is printed on a predetermined electrode of the substrate, and the cream solder is printed at a predetermined position on the substrate. A method of performing reflow for positioning and mounting a bare chip component and a resin exterior component which is other surface mount component and then heating the substrate is known (for example, see Patent Document 1).

JP 2001-308268 A

In the printing process in the conventional substrate manufacturing method, printing is performed on a plurality of substrates while continuing to use cream solder set in the apparatus. When printing is completed on a predetermined number of substrates, a printing mask as a printing member is removed from the apparatus and washed, and a cleaning process is performed in which the washed printing mask and new cream solder are set. After this cleaning process, the next repeated printing is performed with the set new cream solder.
In order to reduce the waiting amount of the substrate between the printing step and the component mounting step which is the next step, the tact time (processing interval) which is the processing start time interval for the substrate is set between the printing step and the component mounting step. It is desirable to match as much as possible. Here, the printing processing time per substrate may be shorter than the mounting processing time per substrate in the component mounting process. In this case, in order to achieve the request to match the tact time between the two processes, the waiting time other than the print processing time in the tact time of the printing process is set to match the tact time between the two processes. Set to. However, depending on the setting of this waiting time (this is due to the difference between the printing processing time and the mounting processing time), it has been found that printing failure occurs. That is, the longer the waiting time during the tact time of the printing step, the more the solder paste is dried during the waiting time. When the cream solder is dried, for example, clogging of the opening of the printing mask occurs, and printing failure of the cream solder is likely to occur. The drying of the cream solder is such that it does not become a problem for a while after the cleaning process is performed in which the printing mask is removed and washed, and the washed printing mask and new cream solder are set. However, it has been found that when the elapsed time from the completion of the cleaning process becomes longer, the drying of the cream solder during the waiting time tends to proceed rapidly and printing defects are likely to occur.

  The present invention has been made in view of the above problems, and it is possible to adjust the tact time between the printing process and the next process so as to suppress an increase in the temporary storage amount of the substrate after printing, and to perform printing of the printing apparatus. It is an object of the present invention to provide a printing method and system capable of preventing a printing defect when the elapsed time from cleaning of a printing member becomes long.

In order to achieve the above object, the invention of claim 1 includes a printing step of printing a conductive printing agent on a predetermined electrode of a substrate before mounting an electronic component for surface mounting, and after the printing A printing method comprising: a substrate unloading step for unloading a substrate for the next step; and a cleaning step for cleaning a printing member used for the printing after the printing is repeatedly performed on a plurality of substrates. In the process, the print processing interval per substrate is switched according to the elapsed time after cleaning from the end of cleaning of the printing member. In the substrate unloading process, the process start timing in the next process is adjusted. Then, the printed substrate is unloaded.
According to a second aspect of the present invention, in the printing method of the first aspect, the printing process per one substrate in the printing process until the predetermined switching timing comes from the end of the cleaning of the printing member in the printing process. The interval is adjusted to the processing interval per substrate in the next step, and after the predetermined switching timing has elapsed, the printing processing interval per substrate in the printing step is set to one substrate in the next step. It is characterized by being shorter than the per-process interval.
According to a third aspect of the present invention, in the printing method of the second aspect, the substrate on which the printing agent is printed is a substrate having an electrode to be printed for a bare chip.
According to a fourth aspect of the present invention, there is provided a printing apparatus that prints a conductive printing agent on a predetermined electrode of a substrate before a surface mounting electronic component is mounted, and the printed substrate is directed to the next process. And a substrate unloading device for unloading, and the printing device performs printing processing intervals per substrate according to the elapsed time after cleaning from the end of cleaning of the printing member used for printing. The substrate unloading apparatus unloads the printed substrate in accordance with the processing start timing in the next process.
The invention according to claim 5 is the printing system according to claim 4, wherein the printing apparatus sets a printing processing interval per substrate until a predetermined switching timing comes from the end of cleaning of the printing member. After the predetermined switching timing has passed, the printing processing interval per substrate in the printing step is set to the processing interval per substrate in the next step. It is characterized by being shorter than the processing interval.
According to a sixth aspect of the present invention, in the printing system of the fourth aspect, the substrate on which the printing agent is printed is a substrate having a printing target electrode for a bare chip component.

According to the first to sixth aspects of the present invention, the print processing interval per substrate can be switched as follows according to the elapsed time after cleaning from the end of cleaning of the printing member used for printing.
That is, since the printing agent is difficult to dry until the predetermined switching timing at which the drying of the conductive printing agent is likely to proceed rapidly from the end of cleaning of the printing member, printing per substrate is possible. The processing interval is adjusted to the processing interval per substrate in the next step. In this way, by adjusting the printing processing interval to the processing interval in the next step, while suppressing an increase in the temporary storage amount of the printed substrate, the printing step is carried out by carrying out the printed substrate in accordance with the processing start timing in the next step. And the tact time between the next process can be adjusted.
After the predetermined switching timing elapses, the printing agent is easily dried rapidly, so that the printing processing interval per substrate is shorter than the processing interval per substrate in the next step. Thus, by making the printing processing interval shorter than the processing interval in the next step, printing failure when the elapsed time from cleaning of the printing member of the printing apparatus becomes longer is prevented, and at the processing start timing in the next step. In addition, the tact time can be adjusted between the printing process and the next process by unloading the printed substrate.
As described above, the tact time can be adjusted between the printing process and the next process so as to suppress the increase in the temporary storage amount of the substrate after printing, and the elapsed time from cleaning of the printing member of the printing apparatus is long. There is an effect that it is possible to prevent a printing defect when it becomes.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a process diagram showing each processing process in a substrate manufacturing method including a printing method according to the present embodiment. 2A and 2B are respectively an explanatory view and a plan view of a cross-sectional structure of the electronic circuit board 1 manufactured by the substrate manufacturing method of the present embodiment.
As shown in FIG. 2A, the electronic circuit board 1 includes a surface-mounting resin exterior component (hereinafter referred to as a “resin exterior chip”) 1b as a first electronic component, and a second electronic component. This is a substrate on which a bare chip component for surface mounting (hereinafter simply referred to as “bare chip”) 1c is mounted. The resin exterior chip 1b is a component such as a semiconductor IC sealed with resin, a resistor, and a capacitor, and the bare chip 1c is a bare semiconductor IC chip before being sealed with resin. A resin is filled between the substrate 1 and the bare chip 1c so that the bare chip 1c is stably fixed on the substrate 1. On the other hand, the resin is not filled between the substrate 1 and the resin exterior chip 1b.

  Further, as shown in FIG. 2B, the substrate 1 is a substrate in which a large number (for example, several tens to several hundreds) of individual substrates 100 having a predetermined function and the same shape and circuit specifications are arranged in a lump. It is. The substrate 1 is separated into individual substrates 100 after the resin-coated chip 1b and the bare chip 1c are mounted and subjected to a predetermined function test. Each of the separated individual substrates 100 is used as a circuit module component having a predetermined function.

In the substrate manufacturing method shown in FIG. 1, first, a solder printing step (p1) for printing cream solder as a conductive printing agent on the substrate 1 before mounting the resin-coated chip 1b or the bare chip 1c is performed. The After this solder printing process, the same mounting part 1b is used to mount the resin-coated chip 1b on a predetermined position of the substrate 1, and the bare chip 1c is mounted on the substrate 1 at a predetermined position. And a second mounting step (p3) to be mounted on. Note that the order of the first mounting step and the second mounting step may be reversed.
Next, a reflow process (p4) is performed after the mounting process of the resin exterior chip 1b and the bare chip 1c. Thus, after performing two mounting processes (p2, p3), the frequency | count of a heating with respect to the electronic component on the board | substrate 1 can be reduced by performing a reflow process.
Next, after the reflow step, an underfill treatment step (p5) is performed in which the gap between the substrate 1 and the bare chip 1c is filled with a resin as a filler that fills the gap.
As described above, the exterior chip 1b not subjected to the underfill process and the bare chip 1c subjected to the underfill process can be mixedly mounted on the same substrate 1.

  As mentioned above, according to the electronic circuit board manufacturing method of this embodiment, since the frequency | count of a heating with respect to the electronic component mounted on the board | substrate 1 is reduced, the frequency | count of the heat shock given to these electronic components can be reduced. Moreover, since the reflow process of the resin exterior component 1b and the reflow process of the bare chip 1c, which were conventionally performed individually, are simultaneously performed, the number of processing steps can be reduced and workability can be improved.

  A substrate manufacturing system capable of realizing the electronic circuit board manufacturing method includes a printing apparatus that prints cream solder on predetermined electrodes of the substrate 1 and a component mounting apparatus that positions and mounts components at predetermined positions on the substrate 1. As a mounting device, a reflow device for heating the substrate 1 on which the bare chip 1c and the resin sheathing chip 1b are mounted, and an underfill device for filling the gap between the bare chip 1c and the substrate 1 with resin. it can.

Next, each process of the said board | substrate manufacturing method is demonstrated in detail.
[Solder printing process]
FIG. 3 is a schematic configuration diagram of a printing apparatus used in the solder printing process according to the present embodiment. This printing apparatus prints cream solder 3 on a substrate 1 using a printing mask 2 which is a stencil mask made of a plastic material. In this printing apparatus, the printing mask 2 mounted on the frame member 2 b is fixed by a fixing member 4. The substrate 1 is held on the stage 5 so that the electrode formation surface on which the electrodes are formed is the upper surface. Driving means for driving the stage 5 is provided on the lower surface of the stage 5. This driving means is configured by using a stepping motor 6 that can rotate forward and backward, and a vertical movement mechanism 7 that includes a ball screw and a nut (not shown) that is rotationally driven by the motor 6. By controlling the rotation of the stepping motor 6, the stage 5 can be driven in the vertical direction, and the substrate 1 can be moved to a printing position in contact with the printing mask 2 or separated from the printing mask 2.

  Above the stage 5 moved to the printing position, a filling means for filling the cream solder 3 in the opening 9 of the printing mask 2 is provided. This filling means, as shown in FIG. 4, is for driving the squeegee 8 as a filling member for imprinting the cream solder 3 into the opening 9 of the printing mask 2, and for driving the squeegee 8 in the left-right direction in the figure by a drive belt or the like. The squeegee drive mechanism (not shown) is used. The printing mask 2 is provided with openings 9 corresponding to electrodes on which resin-coated chips that do not need to be subjected to underfill processing are mounted and electrodes on which second electronic components that are subjected to underfill processing are mounted. It has been. For example, in the case of a micro print pattern, the opening 9 is a rectangular opening having a diameter of about 100 to 200 μm or a circular opening having a similar diameter.

  Here, when the opening 9 of the printing mask 2 is a square opening, the inner wall surface substantially perpendicular to the substrate surface (upper surface) of the opening 9 is in the squeegee movement direction (A direction in the figure). The downstream side surface located on the downstream side is preferably an inclined surface 9a inclined with respect to the squeegee movement direction A. Of the inner wall surface of the opening 9 of the printing mask 2, the upstream side surface located on the upstream side in the squeegee movement direction (A direction in the figure) is also the same with respect to the squeegee movement direction (A direction in the figure). The inclined surface 9b is preferably inclined. For example, as shown in FIG. 4, the inclined surfaces 9a and 9b of the printing mask 2 are inclined by approximately 45 degrees with respect to the squeegee movement direction (A direction in the figure).

  The cream solder used when printing using the fine pattern printing mask 2 is preferably, for example, an solder having an average particle size of 10 μm or less and a flux component content of about 11% by mass.

In the printing apparatus having the above-described configuration, first, the printing mask 2 is fixed by the fixing member 4, and then the motor 6 is rotationally driven to raise the stage 5 holding the substrate 1 and bring it into contact with the printing mask 2. Then, the cream solder 3 is set on the upper surface of the printing mask 2 and the squeegee 8 is moved in the direction of the arrow A, whereby the opening 9 of the printing mask 2 is filled with the cream solder 3 and printed (see FIG. 5A). ).
Next, in a state where the printing mask 2 filled with the cream solder 3 and the substrate 1 are kept in contact with each other, timing of a waiting time set in advance based on the printing conditions is started. Then, in a state where the predetermined waiting time has elapsed and the tacking force (adhesive force) of the cream solder 3 has been increased, the motor 6 is rotationally driven to lower the stage 5 in the direction of arrow B in FIG. The printing mask 2 is separated (see FIG. 5B). By this separation operation, an electrode made of cream solder 3 is formed on the pad electrode 1 a of the substrate 1.

Further, in the printing apparatus of the present embodiment, the inner wall surface on the downstream side in the squeegee movement direction of the opening 9 of the printing mask 2 is an inclined surface 9 a that is inclined with respect to the keyge movement direction. Thereby, the cream solder 3 moved by the squeegee 8 is guided to the inclined surface 9a, and the inner wall surface on the downstream side with respect to the squeegee moving direction of the opening 9 does not become a resistance to movement. Therefore, the cream solder 3 is not filled more than necessary on the inner wall surface on the downstream side in the squeegee movement direction.
Further, the inner wall surface on the upstream side in the squeegee moving direction of the opening 9 of the printing mask 2 is also an inclined surface 9b that is inclined with respect to the squeegee moving direction. As a result, the cream solder 3 that has been moved by the squeegee 8 does not fall in the vicinity of the inner wall surface of the opening 9, and the solder solder 3 is sufficient on the inner wall surface side that is perpendicular to the squeegee movement direction of the opening 9. There is no problem of not being filled.
As described above, by using the printing mask 2 having the inclined surfaces 9a and 9b, the filling surface (upper surface) 3a of the solder cream filled in the opening 9 is substantially flat as shown in FIG. Can be a surface. In particular, when the solder cream 3 is printed on the microelectrode 1a of 0.1 mm or less, it is effective not to form a surface perpendicular to the squeegee movement direction on the inner wall surface of the mask opening 9 as described above. is there. In the case of a microelectrode, the amount of solder cream printed on the microelectrode is also reduced. As a result of the reduction in the amount of solder cream, even a slight error in the amount of solder cream on the microelectrode may lead to poor bonding with the electronic component. Therefore, the amount of solder cream on the microelectrode can be made uniform by not forming a surface perpendicular to the squeegee movement direction on the inner wall surface of the printing mask opening 9 as described above. Can be reliably prevented.

[Mounting process]
FIG. 6 is a perspective view showing an example of a schematic configuration of a mounting device 10 as a component mounting device used in a mounting process for mounting the resin-coated chip 1b and the bare chip 1c on the substrate 1. FIG. The mounting apparatus 10 uses a reel cassette 12 as a component holding member for both the resin-coated chip 1b and the bare chip 1c. A plurality of reel cassettes 12 are fixed on the cassette moving table 3 in a continuous manner. In the reel cassette 12, a reel 15 in which a carrier tape is wound around a winding shaft that is a packing container is set. Further, the cassette moving table 13 is moved in the X direction in the figure by a driving mechanism (not shown).

  On the front side of the cassette moving table 13 in the figure, a rotating table 17 that rotates around the rotating suspension column 16 is disposed. On the circular orbit of the turntable 17, a component suction unit 18 that sucks surface mounting electronic components such as the resin outer chip 1b and the bare chip 1c is fixed. The component suction unit 18 includes a suction nozzle 18a for sucking electronic components on the lower end side. The suction nozzle 18a has a nozzle hole on its bottom surface, and sucks an electronic component by sucking gas from the nozzle hole. The suction nozzle 18a sucks an electronic component held on the component supply unit 12a of the reel cassette 12 positioned immediately below the position A when it is moved to the position A in the figure by the rotation of the rotary table 17. Thereby, the electronic component is sucked and held at the tip of the suction nozzle 18a. By moving the cassette moving table 13 in the X direction in the figure, among the plurality of reel cassettes 12, the reel cassette corresponding to the electronic component to be sucked is moved to the suction position (position A in the figure) of the suction nozzle 18a. Let

  Below the rotary table 17 is disposed an XY table 19 that is moved in the X and Y directions in the figure by a drive mechanism (not shown), and the substrate 1 is fixed on the upper surface thereof. A predetermined electrode pattern is formed on the surface of the substrate 1, and a solder paste pattern corresponding to each lead is printed on the electrode pattern in advance by a solder printing process. The electronic parts such as the resin outer chip 1b and the bare chip 1c adsorbed by the adsorption nozzle 18a are moved to a predetermined position on the substrate 1 by the rotation of the rotary table 7 or the movement of the XY table 19, and then the lead Is mounted by being positioned by the suction nozzle 18a so as to be placed on the corresponding solder paste pattern. It is also possible to use a mounting device that adjusts the mounting position by moving only one of the printed circuit board 1 and the suction nozzle 18a.

  FIG. 7 is a perspective view showing an example of the reel cassette 12 in a state where the reel 15 is set. As illustrated, the reel cassette 12 is formed in a flat shape, and a component supply unit 12c is provided on the base 12b. A reel holder 12d is provided on the rear end side of the base 12b, and a reel 15 including a winding shaft and a carrier tape 11 is set therein. In addition, a take-up reel 12e is provided above the component supply unit 12c so as to take up the carrier tape fed from the reel 15 as electronic components are supplied. Note that the reel winding shaft has the character of a packaging container.

  Although not shown in FIG. 7 for the sake of convenience, all reel cassettes 12 in the facility are labeled with cassette serial number barcodes, which are mounting device identification information for individually identifying each. Is affixed.

  As shown in FIG. 8, the carrier tape 11 is provided with recesses 11a for holding the electronic components 1b and 1c at equal intervals, and holds, for example, 2000 electronic components in the recesses 11a in the initial state. Then, as the take-up reel 12e rotates, it moves in the component supply unit 12c, and the recess 11a moves to the component supply unit 12a provided near the tip of the component supply unit 12c. The electronic component in the recess 11a that has moved to the component supply unit 12a is sucked by the suction nozzle 18a of the mount device.

FIG. 9 is a schematic diagram showing a state in which the suction nozzle 18a sucks the electronic components 1b and 1c held in the recess 11a of the carrier tape 11. As shown in FIG. When the recessed part 11a is located in the component supply part 12a, the movement of the carrier tape 11 is stopped. Then, the suction nozzle 18 a of the mounting device 10 moves downward in the figure and comes into contact with the surface 11 b around the concave portion of the carrier tape 11. Here, the depth of the recess 11a is set so that the electronic component does not protrude from the surface 11b around the opening of the carrier tape. Further, the bottom surface of the suction nozzle 18a provided with the nozzle holes is brought into contact with the surface 11b around the opening of the carrier tape. This prevents the electronic component and the suction nozzle 18a from coming into contact with each other, and prevents the electronic component from being damaged by the suction nozzle 18a coming into contact with the electronic component 1b when the suction nozzle 18a is lowered.
When the suction nozzle 18a comes into contact with the surface 11b of the carrier tape 11, the electronic component held in the recess 11a is sucked by the suction nozzle 18a and sucked by the suction nozzle 18a. Since the suction nozzle 18a does not block all the openings of the recess 11a, and the air hole 18b is formed between the suction nozzle 18a and the suction nozzle 18a during the suction operation, the inside of the recess 11a is in a vacuum state. There is no. When the electronic components 1b and 1c are attracted to the suction nozzle 18a, the suction nozzle 18a is raised and positioned and mounted at a predetermined position on the substrate 1 on the turntable 19.

  FIG. 10 is a perspective view showing a schematic configuration of a mounting apparatus 20 according to another configuration example. This mounting device 20 uses a tray 22 as a component holding member for each of the resin-coated chip 1b and the bare chip 1c. As shown in FIG. 10, a plurality of trays 22 are fixed on a tray base 23 via a buffer material 21 such as rubber. A plurality of recesses 22a are formed at equal intervals in the tray 22, and electronic components 1b and 1c are held in the recesses 22a, respectively. Also in the mounting device 20, as in the first mounting device 10, the XY table 29 that holds the substrate 1 and the electronic components 1 b and 1 c held in the concave portion 22 a are adsorbed, and the substrate 1 is predetermined. A suction nozzle 28a disposed at a position, a rotary table 27 for holding the suction nozzle 28a, and the like are provided. Then, the electronic components 1b and 1c held in the recess 22a are sequentially sucked by the suction nozzle 28a and are arranged at predetermined positions on the substrate 1. When the electronic components 1b and 1c are removed from the tray 22, the suction nozzle 28a is moved to the next tray, and a CCD camera (not shown) attached to the suction nozzle 28a is positioned diagonally with one end of the tray 22 and this end. The position of the tray 22 on the tray table 23 is detected by detecting the end. When the position of the tray 22 is detected, the electronic components 1b and 1c held in the concave portion 22a of the tray are again picked up by the nozzle and arranged at a predetermined position on the substrate.

  Also in the mounting device 20, when the electronic components 1b and 1c held in the recess 22a of the tray 22 are attracted to the suction nozzle 28a, as shown in FIG. 10, the opening surface 22b of the tray 22 and the suction nozzle 28a are The electronic parts 1b and 1c and the suction nozzle 28a are prevented from coming into contact with each other. Thereby, also in this mounting apparatus 20, it is prevented that the electronic components 1b and 1c are damaged by contact | abutting with the suction nozzle 28a. When the suction nozzle 28a comes into contact with the opening surface 22b of the tray 22, the tray 22 vibrates due to an impact at the time of contact. The electronic components 1b and 1c held in the recess 22a are aligned so as to be arranged on the substrate 1 in a predetermined direction. However, the vibration of the tray 22 may change the orientation of the electronic components 1b and 1c held in the recess 22a. In particular, in the case of the bare chip 1c having a small size, the direction is easily changed by vibration. When the orientation of the electronic components 1b and 1c held in the recess 22a changes in this way, the electronic components 1b and 1c cannot be arranged on the substrate 1 in the correct orientation. Therefore, the mounting device 20 of this configuration example includes a buffer material 21 between the tray 22 and the tray base 23. Thereby, even if the suction nozzle 28a abuts on the surface of the tray 22, the shock absorbing material 21 absorbs an impact at the time of abutment, so that the vibration of the tray 22 is alleviated. Therefore, the direction of the electronic components 1b and 1c held in the recess 22a is prevented from changing, and the electronic components 1b and 1c are prevented from being arranged on the substrate 1 in the correct direction. In this configuration example, the cushioning material 21 is disposed between the tray 22 and the tray base 23. However, the cushioning material is disposed on the surface of the tray 22, or the tray contact surface of the suction nozzle 28a. A cushioning material may be provided.

  FIG. 12 is a perspective view showing a schematic configuration of a mount device 30 according to still another configuration example. In the mounting device 30, a reel cassette 32 is disposed as a component holding member of the resin-coated chip 1 b that is not subjected to underfill processing on the right side (back side) in FIG. 11. A tray 42 is disposed on the left side (front side) in FIG. 11 as a component holding member of the bare chip 1c to be subjected to underfill processing.

The rotary table 37 is provided with a first suction nozzle 38a that sucks the resin-coated chip 1b held on the reel cassette 32 and a second suction nozzle 48a that sucks the bare chip 1c held on the tray 42. ing. Since the bare chip 1c is smaller than the resin-coated chip 1b, when the resin-coated chip 1b is to be sucked by the suction nozzle 48a designed for sucking the bare chip 1c, a sufficient suction force to hold the resin-coated chip 1b. May not be able to get. In addition, when trying to suck the bare chip 1c with the suction nozzle 38a designed for sucking the resin-coated chip 1b, on the contrary, the suction force is too strong and the bare chip 1c comes into contact with the nozzle with momentum. The bare chip 1c may be damaged. For this reason, the mounting device 30 of this configuration example includes a first suction nozzle 38a for a resin-coated chip and a second suction nozzle 48a for a bare chip.
Here, when mounting the resin-coated chip 1b on the substrate 1 on the XY table 39, the rotary table 37 is rotated and the first suction nozzle 38a is moved to the first suction position (position A in the figure). Move. When the first suction nozzle 38a moves to the first suction position, the nozzle is lowered and brought into contact with the opening surface of the carrier tape 11, and the resin held in the recess when the first suction nozzle 38a is lowered. The exterior chip 1b and the first suction nozzle 38a are prevented from coming into contact with each other. Then, the resin-covered chip 1 b held in the recess is adsorbed by the nozzle and disposed at a predetermined position on the substrate 1.
On the other hand, when mounting the bare chip 1c on the substrate 1 on the XY table 39, the rotary table 37 is rotated, and the second suction nozzle 48a is moved to the second suction position (position B in the figure). Then, the nozzle is lowered and brought into contact with the opening surface of the tray 42, so that the bare chip 1c held in the concave portion and the second suction nozzle 48a do not come into contact with each other when the second suction nozzle 48a is lowered. I am doing so.

  Also, in the case of the mounting device 30 of this configuration example, the buffer material 21 is provided between the tray 42 and the tray base 43 as in the mounting device 20 described above, and the second suction nozzle 48 a is provided on the opening surface of the tray 42. It absorbs the impact force when abutting. Then, the bare chip 1c held in the concave portion is sucked by the suction nozzle 48a and mounted at a predetermined position on the substrate 1.

  In addition, although the mounting apparatus 30 of this structural example uses the reel cassette 32 as a component holding member of the resin exterior chip | tip 1b, and uses the tray 42 as a component holding member of the bare chip 1c, it is not restricted to this. For example, a tray may be used as the component holding member for the resin-coated chip 1b, and a reel cassette may be used as the component holding member for the bare chip 1c. Alternatively, two rotation tables 37 may be provided, one serving as the first rotation table holding the first suction nozzle 38a and the other serving as the second rotation table holding the second suction nozzle 48a. In this way, the disposing step can be speeded up by providing the rotary table separately.

  According to the mounting devices 10, 20, and 30 having the above-described configuration, both the resin exterior chip 1 b and the bare chip 1 c can be performed by the same mounting device 30, thereby reducing the manufacturing time, manufacturing cost, and the like of substrate manufacturing. be able to.

In the mounting devices 10, 20, 30 having the above-described configuration, it is preferable to switch the suction pressure when the suction nozzles 18 a, 28 a, 38 a, 48 a suck parts. Specifically, the adsorption pressure is switched so that the adsorption pressure when the adsorption nozzle adsorbs the bare chip 1c is smaller than the adsorption pressure when the adsorption nozzle adsorbs the resin-coated chip 1b. For example, the adsorption pressure when the adsorption nozzle adsorbs the bare chip 1c is reduced by 80% (20% of the standard pressure) of the adsorption pressure (standard pressure) when the adsorption nozzle adsorbs the resin-coated chip 1b. By switching the suction pressure in this manner, the resin-coated chip 1b can be reliably held by being sucked by the suction nozzle while preventing the bare chip from being damaged by the impact when the bare chip 1c is attracted to the suction nozzle. This is particularly effective when a reel cassette is used as the component holding member.
The adsorption pressure switching means for switching the adsorption pressure can be configured using a controller of each mount device 10, 20, 30 and a suction device such as a suction pump controlled by the controller.

Further, in the mounting devices 10, 20, and 30 having the above-described configuration, each of the suction nozzles has a constant impact force (dynamic load) generated when attaching at least one of the bare chip 1 c and the resin exterior chip 1 b to the substrate. It is preferable to change at least one of the bottom dead center and the moving speed of the suction nozzle when the component is mounted on the substrate. In particular, since the bare chip 1c has a high possibility of being damaged by an impact when being mounted on the substrate, the suction nozzle of the bare chip 1c is mounted so that the impact force (dynamic load) is lower than that of the resin-coated chip 1b. Set at least one of bottom dead center and moving speed. Here, the “bottom dead center” is the position of the lowest point where the suction nozzle is lowered until it comes closest to the substrate.
The bottom dead center and the moving speed of the suction nozzle can be set, for example, as follows. First, a pseudo substrate member having a load cell to which a pressure sensor as force detecting means is attached is set at a position where the substrate is set in the mounting apparatus. With respect to the pseudo substrate member, the suction nozzle that sucks the component is lowered and stopped at a predetermined position. The impact force (dynamic load) at the time of stop is calculated based on the output of the pressure sensor of the load cell. This measurement and calculation are performed by changing the bottom dead center and moving speed of the suction nozzle. Then, the bottom dead center and the moving speed of the suction nozzle are set so that the impact force (dynamic load) is below a certain force. Here, when one unit of the moving step amount when the suction nozzle descends is large, the position of the suction nozzle when the component held by the suction nozzle comes into contact and the pressure sensor of the load cell starts to output is determined. It may be the bottom dead center.
As described above, by reducing the impact force (dynamic load) generated when the above parts are mounted on the board to a predetermined level or less, excessive crushing of the solder can be prevented and stress applied to the parts can be reduced. Can prevent the parts from being damaged. In particular, this is effective when the component to be mounted is a bare chip that is easily damaged.
If the moving speed when the suction nozzle is lowered is large, variation in the stop position of the suction nozzle becomes large and it becomes difficult to control the impact force (dynamic load), while the moving speed when the suction nozzle is lowered is too slow. The mount processing time becomes long. Therefore, it is preferable to control the movement of the suction nozzle so that the suction nozzle is lowered at a higher speed to the vicinity of the substrate and lowered at a lower speed from there to the bottom dead center. Specifically, a standard speed of about several tens of mm / sec until the distance between the bottom surface of the component held by the suction nozzle and the surface of the substrate reaches a preset distance (for example, about 0.2 to 0.4 mm) ( For example, it is moved at a moving speed of about several mm / sec (for example, 2 mm / sec) from the position to the bottom dead center. Thus, by controlling the moving speed of the suction nozzle in two steps, the impact force (dynamic load) generated when the component is mounted on the substrate is suppressed to a predetermined magnitude or less while suppressing an increase in the mounting processing time. It becomes possible. Here, in the case of the resin exterior component 1b in which the component to be mounted is not easily damaged, the mounting speed is given priority, without performing the two-stage control of the moving speed, so that the mounting speed is given priority. You may make it move at a speed | rate (for example, 88 mm / sec).
The setting changing means for changing the setting of at least one of the bottom dead center and the moving speed of the suction nozzle can be configured using the controller of each of the mounting devices 10, 20, 30.

Further, in the mounting devices 10, 20, and 30 configured as described above, an impact force (dynamic load) generated when the suction nozzle picks up at least one of the bare chip 1 c and the resin exterior chip 1 b from a component holding member such as a tape or a tray. It is preferable to change the setting of at least one of the bottom dead center and the moving speed of the suction nozzle when picking up the components so as to be constant. In particular, since the bare chip 1c is highly likely to be damaged by an impact when the suction nozzle comes into contact with the tape or the tray, the impact force (dynamic load) when picking up the bare chip 1c is the impact when picking up the resin-coated chip 1b. At least one of the bottom dead center and the moving speed of the suction nozzle at the time of picking up the bare chip 1c is set so as to be lower than the force. Here, the “bottom dead center” is the position of the lowest point where the suction nozzle is lowered until it comes closest to the component holding member such as a tape or a tray.
The bottom dead center and the moving speed of the suction nozzle can be set, for example, as follows. First, a force detection member having a load cell to which a pressure sensor as force detection means is attached is set at a position where a component holding member such as a tape or a tray is set in the mounting device. The suction nozzle is lowered with respect to the force detection member and stopped at a predetermined position. The impact force (dynamic load) at the time of stop is calculated based on the output of the pressure sensor of the load cell. This measurement and calculation are performed by changing the bottom dead center and moving speed of the suction nozzle. Then, the bottom dead center and the moving speed of the suction nozzle are set so that the impact force (dynamic load) is below a certain force. Here, when one unit of the moving step amount when the suction nozzle descends is large, the position of the suction nozzle when the suction nozzle comes into contact and the pressure sensor of the load cell starts to output may be set as the bottom dead center. .
As described above, by making the impact force (dynamic load) generated when picking up the part below a predetermined magnitude, it is possible to reduce the impact applied to the part and prevent damage to the part. . This is particularly effective when the pickup target component is a bare chip that is easily damaged.
If the moving speed when the suction nozzle is lowered is large, variation in the stop position of the suction nozzle becomes large and it becomes difficult to control the impact force (dynamic load), while the moving speed when the suction nozzle is lowered is too slow. The part pick-up processing time becomes longer. Therefore, it is preferable to control the movement of the suction nozzle so that the suction nozzle is lowered at a high speed to the vicinity of a component holding member such as a tape or a tray and then lowered to a bottom dead center at a lower speed. . Specifically, a standard of about several tens of mm / sec until the distance between the tip of the suction nozzle and the surface of a component holding member such as a tape or tray reaches a preset distance (for example, about 0.2 to 0.4 mm). It is moved at a speed (for example, 88 mm / sec) and moved from that position to the bottom dead center at a movement speed of about several mm / sec (for example, 2 mm / sec). In this way, by controlling the moving speed of the suction nozzle in two steps, the impact force (dynamic load) generated when picking up a component is kept below a predetermined magnitude while suppressing an increase in the component pickup processing time. Is possible. Here, in the case of the resin exterior part 1b in which the picked up part is not easily damaged, from the start of movement to the bottom dead center without performing the two-step control of the moving speed so as to give priority to the part picking up speed. You may make it move at a standard speed (for example, 88 mm / sec).
The setting change means for changing the setting of at least one of the bottom dead center and the moving speed of the suction nozzle when picking up and picking up the above components can also be configured using the controller of each mount device 10, 20, 30. .

[Underfill process]
FIG. 13 is an explanatory diagram of the underfill processing step. In this underfill processing step, a gap 55 between the substrate 1 and the bare chip 1c generated by the interposition of the bump 1d is filled with a resin 55 as a filler that fills the gap 54. In FIG. 13, the resin 55 is first supplied (applied) to a portion of at least one side of the gap 54 between the substrate 1 and the bare chip 1 c by the dispenser 56. Then, the resin 55 applied on the substrate 1 penetrates into the gap due to capillary action due to the gap 54 between the substrate 1 and the bare chip 1c. Thereby, the resin 55 is filled between the bare chip 1 c and the substrate 1, and the bare chip 1 c can be reliably fixed on the substrate 1. The underfill process is not limited to this and can be variously changed. For example, the substrate 1 may be vibrated using an ultrasonic application device or the like, and the resin 55 may be filled in the gap 54 between the substrate 1 and the bare chip 1c. Thus, by giving vibration to the substrate 1, it is possible to shorten the time until the resin 55 is filled between the bare chip 1 c and the substrate 1.

Next, switching control of the printing processing interval in the solder printing process which is a part of the substrate manufacturing method of the present embodiment will be described.
As shown in FIG. 14, the substrate manufacturing system according to the present embodiment includes a printing system 200 in which a printing device 210 and a buffer conveyor 220 as a substrate carry-out device with a substrate storage function are combined. The buffer conveyor 220 temporarily stores the substrate 1 after printing by the printing device 210 and prints it toward the mounter device 240 (10, 20, 30) of the next process via the print inspection device 230 at a predetermined timing. Unload the subsequent substrate. The buffer conveyor 220 is, for example, a substrate extrusion unit that extrudes a substrate held in one of the substrate holding shelves having a plurality of substrate holding shelves and a substrate holding shelf of the substrate holding unit toward the next process. And a mechanism. For example, the substrate push-out mechanism can be configured using an air cylinder controlled by a controller and a substrate push-out member provided on a movable part of the air cylinder.

As described above, when the cream solder 3 is printed on the substrate 1 by the printing apparatus 210, there are the following problems. That is, since the printing processing time per substrate is shorter than the mounting processing time per substrate on which components in the subsequent process are mounted, the processing interval (tact time) between the printing step and the mounting step is adjusted. There is a need. For example, the tact time is adjusted by setting the printing processing interval in the printing process to be longer than the printing processing time per one substrate so as to match the processing interval in the subsequent mounting step.
However, if the printing process interval in the printing process is set to be longer than the printing process time per substrate, there is a possibility that a waiting time during which printing is not performed by the printing apparatus 210 occurs and a printing defect may occur. I found out that When such a waiting time occurs, drying of the cream solder 3 supplied onto the printing mask 2 of the printing apparatus 210 proceeds during the waiting time. When the cream solder adhering to the printing mask is dried, the opening of the printing mask is clogged, and the printing failure of the cream solder 3 is likely to occur. The cream solder 3 adhering to the printing mask 2 is dried for a while after the cleaning of setting the new cream solder 3 by removing the printing member such as the printing mask 2 of the printing apparatus 210 and cleaning it. However, if the elapsed time from the cleaning becomes long, the drying of the cream solder during the waiting time is likely to proceed rapidly and printing defects are likely to occur.

FIG. 15 is a graph showing an example of the relationship between the elapsed time from the cleaning and printing failure (number of printing failure points per substrate). As shown in FIG. 2B, the single substrate 1 is formed in a lump by arranging a large number (for example, several tens to several hundreds) of individual substrates 100 having the same shape and circuit specifications having a predetermined function. Substrate. Each individual substrate 100 included in this substrate 1 has several printing points. The print quality of these print points can be inspected by the above-described print inspection apparatus 230.
According to FIG. 15, it can be seen that the printing failure is small until the elapsed time from the cleaning is up to 4 hours, and the printing failure is rapidly increased after the elapsed time from the cleaning exceeds 4 hours. In this example, the next cleaning is performed when the elapsed time from cleaning reaches 6 hours.

FIG. 16 is a graph showing an example of the relationship between the printing processing interval in the printing apparatus 210 and the printing failure (number of printing failure points per substrate) when the elapsed times from the cleaning are different from each other. Note that the minimum time (minimum processing time) of the printing processing interval of the printing apparatus 210 of this example is about 2 minutes 30 seconds.
As indicated by the line A in FIG. 16, the printing defects gradually increase with the increase of the printing processing interval until the elapsed time from the cleaning up to 4 hours. However, as indicated by the line B in FIG. 16, when the elapsed time from the cleaning exceeds 4 hours, the number of printing defects rapidly increases when the printing processing interval becomes longer than 2 minutes 30 seconds. Yes.

  On the other hand, if the printing processing interval in the printing process is shortened to the same extent as the printing processing time per substrate, the number of printed substrates 1 to be temporarily stored so as to wait for the adjustment of the tact time is increased. .

Therefore, in the printing process of the present embodiment, one substrate is printed according to the elapsed time after cleaning from the end of cleaning in which a printing member such as the printing mask 2 used for printing is removed and washed and a new cream solder is set. The print processing interval is switched as follows.
Specifically, as shown in FIG. 17, a predetermined switching timing (in the example of FIGS. 15 and 16 described above, timing when 4 hours elapses) comes from the end of cleaning of the printing member. Until the cream solder 3 used for printing is difficult to dry, the printing processing interval per substrate is set to a standard printing processing interval that matches the processing interval per substrate in the next process (steps 1 and 2). ). Thus, by adjusting the printing processing interval to the processing interval in the next step, it is possible to suppress an increase in the temporary storage amount of the substrate 1 after printing. Moreover, the tact time between the printing process and the next process can be adjusted by carrying out the printed substrate 1 by the buffer conveyor 220 in accordance with the processing start timing in the mounting process.
On the other hand, after the predetermined switching timing has elapsed, the drying of the cream solder 3 is likely to proceed rapidly, so the printing processing interval per substrate is set to the processing interval per substrate in the mounting process (the above standard). It is set so as to be shorter than (print processing interval) (steps 1 and 3). In this way, the printing processing interval is made shorter than the processing interval in the next step, thereby preventing printing defects when the elapsed time from cleaning of the printing member of the printing apparatus 210 becomes longer. Moreover, the tact time between the printing process and the mounting process can be adjusted by carrying out the printed substrate 1 in accordance with the processing start timing in the mounting process.

  As described above, according to the present embodiment, the tact time can be adjusted between the printing process and the subsequent mounting process so as to suppress an increase in the temporary storage amount of the substrate 1 after printing, and the printing mask 2 of the printing apparatus 210 can be adjusted. It is possible to prevent printing defects when the elapsed time from cleaning of the printing member such as the printing time becomes long. In particular, the printed pattern printed on the electrode for the bare chip 1c is a fine pattern having a size of about 100 to 200 μm, for example, and printing defects are likely to occur when the cream solder 3 on the printing mask 2 is dried. . Therefore, printing control for switching the printing processing interval per substrate in accordance with the elapsed time after cleaning from the end of cleaning of the printing member such as the printing mask 2 as in this embodiment is more effective. .

Process drawing which shows each process process in the board | substrate manufacturing method which concerns on embodiment of this invention. (A) is a top view of the electronic circuit board manufactured with the substrate manufacturing method. (B) is explanatory drawing of the cross-sectional structure of the board | substrate. 1 is a schematic configuration diagram of a printing apparatus used in a printing process. Explanatory drawing of the opening part of the printing mask of the printing apparatus. (A) is explanatory drawing which shows the mode of the cream solder with which the opening part of the printing mask was filled with the printing apparatus. (B) is explanatory drawing which shows the mode of the cream solder in the opening part during the separation | spacing operation | movement in the printing apparatus. The schematic block diagram which shows an example of the mounting apparatus used at a mounting process. The perspective view which shows an example of a reel cassette and the reel set to this. Sectional drawing of a carrier tape. The schematic diagram which a suction nozzle adsorb | sucks the electronic component currently hold | maintained at the recessed part of a carrier tape. The schematic block diagram of the mounting apparatus which concerns on the other structural example. The schematic diagram by which an adsorption nozzle adsorb | sucks the electronic component currently hold | maintained at the recessed part of a tray. Furthermore, the schematic block diagram of the mounting apparatus which concerns on another structural example. The schematic diagram which shows an underfill process process. The block diagram which shows schematic structure from a printing apparatus to a mounting apparatus. The graph which shows an example of the relationship between the elapsed time from the cleaning of the printing member and the printing failure. The graph which shows an example of the relationship between the printing process space | interval and printing defect when the elapsed time from cleaning differs mutually. A flowchart of print processing interval switching control.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 1b Resin exterior chip | tip 1c Bare chip | tip 2 Printing mask 3 Cream solder 9 Opening part 10,20,30 Mounting apparatus 12 Reel cassette 18,28,38,48 Component adsorption unit 18a, 28a, 38a, 48a Adsorption nozzle 22 Tray 55 Resin 56 Dispenser 100 Individual substrate 200 Printing system 210 Printing device 220 Buffer conveyor 230 Print inspection device 240 Mounting device

Claims (6)

A printing step of printing a conductive printing agent on a predetermined electrode of the substrate before the electronic component for surface mounting is mounted; a substrate unloading step of unloading the printed substrate for the next step; and A cleaning method for cleaning a printing member used for printing after repeatedly performing printing on a plurality of substrates,
In the printing process, according to the elapsed time after cleaning from the end of cleaning of the printing member, the printing processing interval per substrate is switched,
In the substrate unloading step, the printed substrate is unloaded in accordance with the processing start timing in the next step. In the printing method of Claim 1,
The printing process interval per substrate in the printing process is matched with the processing interval per substrate in the next process until a predetermined switching timing comes from the end of cleaning of the printing member in the printing process. West,
A printing method characterized in that after the predetermined switching timing has elapsed, a printing processing interval per substrate in the printing step is made shorter than a processing interval per substrate in the next step. In the printing method of Claim 2,
The printing method, wherein the substrate on which the printing agent is printed is a substrate having a bare chip printing target electrode. A printing apparatus that prints a conductive printing agent on predetermined electrodes of a substrate before mounting electronic components for surface mounting, and a substrate unloading apparatus that unloads the printed substrate for the next process. Printing system,
The printing apparatus switches a printing processing interval per substrate in accordance with an elapsed time after cleaning from the end of cleaning of a printing member used for printing,
The substrate unloading apparatus unloads the printed substrate in accordance with a processing start timing in a next process. The printing system according to claim 4.
The printing apparatus adjusts the printing processing interval per substrate until the predetermined switching timing comes from the end of cleaning of the printing member, to the processing interval per substrate in the next step,
A printing system characterized in that after the predetermined switching timing elapses, a printing processing interval per substrate in the printing step is made shorter than a processing interval per substrate in the next step. The printing system according to claim 4.
The printing system, wherein the substrate on which the printing agent is printed is a substrate having an electrode to be printed for a bare chip component.

Images