JP4092231B2 - Solder printing jig and solder printing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a solder printing jig and a solder printing method used when solder is printed on an electrode provided on an electrode arrangement surface of a mounted component using a printing mask.
[0002]
[Prior art]
Conventionally, after mounting components such as BGA (Ball Grid Array), LGA (Land Grid Array), and CSP (Chip Size Package) having a microelectrode array are removed from a substrate such as PWB (Printed Wiring Board), this mounting component or There is known an electronic circuit board repairing method called so-called repair in which another mounting component is re-mounted on the component removal region of the board. For example, in BGA, LGA, CSP, etc., these are often mounted on a substrate, a quality test is performed, and when a defect is found, repair is performed and the defective product is often replaced with a new one. Also, for example, when a defect such as BGA is suspected in a quality test in a state where it is mounted on a substrate, but it is determined that it is not defective after removal, the removed BGA or the like is remounted on the substrate. Repair is performed. In such a repair, it may be difficult to print solder on the board using a printing mask because electronic components mounted around the part removal area on the board may interfere. . In such a case, it is necessary to manually print the solder paste on the substrate or the BGA to be remounted.
[0003]
Patent Document 1 discloses a solder printing jig for facilitating such manual solder printing work. This jig is for printing solder on the mounting component, and has a through hole on the upper surface of the positioning base having a recessed portion for holding the mounting component in accordance with the solder application position of the mounting component. It is characterized in that a metal mask with a hole is detachably fitted. When solder printing is performed using this jig, the mounting component is set in a recessed portion provided in the jig with the lower surface of the package (electrode placement surface) facing upward, and the print mask is covered on the lower surface of the package. Cover. Then, a solder paste is applied from above the printing mask to fill the printing holes with solder, and then the printing mask is removed and the mounted component is taken out from the recessed portion. The mounted component taken out from the recessed portion in this way is transported to the substrate on which it is remounted, and then placed and mounted on the component removal region on the substrate.
[0004]
[Patent Document 1]
Registered Utility Model No. 3050218 [0005]
[Problems to be solved by the invention]
However, in the jig disclosed in Patent Document 1, when the mounting component is removed from the recessed portion, the package lower surface (electrode arrangement surface) faces the side where the mounting component is taken in and out. On the other hand, the mounted component removed from the recessed portion is then remounted on the substrate, but the lower surface of the package must face the substrate side during the remounting. Therefore, when solder printing is performed using the above jig, the mounting component is turned upside down after the mounting component is removed from the recessed portion and then transported by the transport member and mounted on the substrate. Troublesome work is required.
Conventionally, in order to quickly and easily perform the mounting component transport operation and the mounting operation, an adsorption method in which the upper surface of the package of the mounting component is adsorbed to vacuum tweezers or the like by a suction force has been adopted. However, when solder printing is performed using the above jig, in order to adopt the suction method, a support member that can support the lower surface of the package without touching the printed solder is superposed from the upper surface of the jig. After turning upside down, the troublesome work of removing the jig with vacuum tweezers or the like becomes necessary.
As described above, when solder printing is performed using the jig, there is a problem in that work efficiency is poor because the above troublesome work is required.
[0006]
In addition, although the above is a problem regarding repair, even if it is necessary to print the solder on the electrode on the electrode placement surface of the mounted component for some reason, the printing process using the printing mask is not limited to repair, and may occur in the same manner. It is a problem.
[0007]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a solder printing jig and a solder printing method that facilitate the work after removing a mounting component from the jig. It is.
[0008]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the invention of claim 1 includes a holding base in which an opening slightly smaller than an electrode arrangement surface of the mounting component is formed on the bottom surface of the recess into which the mounting component is inserted, and the opening And a pressing member for pressing the mounting component inserted into the recess so that the electrode on the electrode arrangement surface is exposed from the side opposite to the electrode arrangement surface. The pressing member is configured to be movable between a retracted position that does not interfere with the mounting position and a pressing position that presses the mounted component.
In the solder printing jig, when the mounting component is inserted into the recess, the electrode placement surface of the mounting component is exposed to the opening formed on the bottom surface of the recess. Therefore, in this jig, the exposed electrode arrangement surface can be covered with a printing mask and the printing holes can be filled with solder. At this time, the pressing member is in the pressing position and presses the mounted component from the side opposite to the electrode arrangement surface. As a result, the mounting component is clamped between the bottom surface portion of the recess in which no opening is formed and the pressing member, and is firmly positioned. Therefore, the solder can be appropriately printed on the electrode on the electrode arrangement surface.
Here, in this jig, the surface opposite to the electrode arrangement surface (the upper surface of the package) is directed to the side where the mounting component is taken in and out of the recess, contrary to the jig of Patent Document 1. Therefore, according to this jig, the state of the mounted component when it is taken out from the recess by the conveying member or the like is the same as the state when it is mounted on the substrate. Therefore, after the mounting component is removed from the recess, the following work such as the mounting work can be performed without performing the troublesome work required for the jig of Patent Document 1. In particular, according to this jig, when carrying and carrying work using the above suction method, the mounted part can be turned upside down after the mounted part is removed from the recessed portion as in the jig of the same document. This is advantageous in that the troublesome work of superimposing a support member separate from the jig on the upper surface of the jig is eliminated. In this jig, since the pressing member can be moved to the retracted position during the insertion / removal operation of the mounting component, the pressing member does not interfere when the mounting component is attached or removed by the conveying member or the like. .
[0009]
According to a second aspect of the present invention, there is provided the solder printing jig according to the first aspect, wherein the pressing member is disposed between the pressing surface of the pressing member and the mounting component and has a larger area than the pressing surface. It has a sheet member provided with the rigidity which can disperse the pressing force by to the whole area.
In general, since the mounted component is weak against a large external pressure, it is desirable that the pressure applied to the mounted component by the pressing member is as small as possible. However, if a simple configuration in which, for example, the mounting component is pressed at one point is employed as the pressing member, the entire mounting component must be pressed at one point so as to withstand the pressure during printing. Therefore, a large pressure is applied to that one point. Therefore, this jig employs a configuration in which the sheet member is disposed between the pressing surface of the pressing member and the mounted component. Since the sheet member has an area larger than the pressing surface of the pressing member and has rigidity capable of dispersing the pressing force by the pressing member over the entire sheet area, the pressure applied to the mounted component can be reduced.
[0010]
Further, the invention of claim 3 inserts the mounting component into a recess having an opening slightly smaller than the electrode arrangement surface of the mounting component on the bottom surface so that the electrode arrangement surface is exposed to the opening, The mounting component inserted into the recess is pressed from the side opposite to the electrode placement surface by a pressing member, the electrode placement surface exposed to the opening is covered with a print mask, and the electrodes on the electrode placement surface and the print mask Position the printing mask so that it coincides with the printing hole, fill the printing hole with solder, remove the printing mask, and then remove the printing mask from the recess so that it does not interfere with the operation The member is moved to take out the mounted component from the recess.
This solder printing method is an example of a method for printing solder using the solder printing jig of claim 1. In this printing method, the surface on the side opposite to the electrode arrangement surface (the upper surface of the package) faces the side where the mounting component is taken in and out of the recess. Therefore, the state of the mounted component when it is taken out from the recess by the conveying member or the like is the same as the state when it is mounted on the substrate. Therefore, when carrying out the carrying work and the mounting work by adopting the above suction method, the mounting part is turned upside down after the mounting part is removed from the recessed portion as necessary in the jig of Patent Document 1, or the jig This eliminates the troublesome work of superimposing a support member separate from the jig on the upper surface. In addition, since the pressing member is moved to the retracted position at the time of inserting / removing the mounting component, the pressing member does not interfere when the mounting component is removed by the conveying member or the like.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is applied to a solder printing jig (hereinafter simply referred to as “jig”) used when solder is printed on a ball-shaped bump electrode on a BGA as a mounting component will be described. .
[0012]
First, the printing mask used for solder printing will be described together with the jig according to the present embodiment.
FIG. 2 is a plan view of the printing mask in the present embodiment.
The printing mask 1 is a plastic mask. As shown in FIG. 2, the printing mask 1 has a plurality of printing holes 4 arranged in a printing pattern corresponding to a BGA bump electrode array. In addition, positioning holes 5 for roughly positioning the printing mask with respect to a jig described later are provided at the four corners of the printing mask 1. This positioning hole 5 is inserted into a pin of a jig described later.
[0013]
The printing hole 4 is formed in the printing mask 1 by ablation processing using an excimer laser device. In the repair in this embodiment, it is desirable to use the printing mask 1 in which each printing hole 4 is formed by ablation processing. Such a printing mask 1 has much smoother inner walls of the printing holes than a metal mask having printing holes processed by a photolithography method or an etching method, and the solder paste can be easily removed from each printing hole. It is because it can improve more. In addition to the excimer laser apparatus, Nd. There are YAG laser (fundamental wavelength 1064 nm, third harmonic 355 nm, harmonic 266 nm) devices, SOR light generators using synchrotrons, and the like.
As a material of the printing mask 1, polyimide, polyester, epoxy, polycarbonate, polyethylene, polyethylene terephthalate (PET), polypropylene, polyacetal, Teflon (registered trademark), polyphenylene sulfide (PPS), or the like is used. In the present embodiment, a printing mask 1 made of heat-resistant polyimide is used.
[0014]
Next, the configuration of the jig that is a characteristic part of the present invention will be described.
Fig.1 (a) is the front view which looked at the jig | tool in this embodiment from the side by which BGA is set or taken out.
FIG. 1B is a back view of the jig.
FIG.1 (c) is sectional drawing of the periphery of a recessed part provided in the jig | tool.
In the following description, of the two surfaces of the jig 10, the side shown in FIG. 1A is the upper surface, and the side shown in FIG. 1B is the lower surface.
[0015]
In the jig 10 according to the present embodiment, a concave portion 11 corresponding to the outer shape of the BGA to be printed is provided at the center of a planar square metal base. An inner wall 12 that forms a space having a size larger than that of the BGA is formed on the upper surface side of the recess 11, and the lower end portion of the inner wall 12 and the upper surface side peripheral portion of the recess 11 are continuous. In addition, an opening 11 a that opens toward the lower surface of the jig 10 is formed at the center of the bottom surface of the recess 11. This opening 11a is slightly smaller than the dimensions of the BGA. Therefore, when the BGA is inserted into the recess 11 from the upper surface of the jig 10, the BGA has an electrode arrangement surface (hereinafter referred to as "package lower surface") on the recess bottom surface portion 11b where the opening 11a is not formed. It is supported in a contact state and held inside the recess 11.
[0016]
Further, as shown in FIG. 1B, pins 13 for roughly positioning the printing mask 1 are erected at the four corners of the lower surface of the jig 10. The pin 13 is provided at a position corresponding to the positioning hole 5 of the printing mask 1. Further, a plate spring 15 for pressing the printing mask 1 is provided on the lower surface of the jig 10. The leaf spring 15 is rotatably attached by a rotation shaft 15a. In the present embodiment, the print mask 1 is set on the lower surface of the jig 10 and solder is printed from the lower surface side of the jig 10.
Further, as shown in FIG. 1A, a plate spring 14 as a pressing member is provided on the upper surface of the jig 10. The leaf spring 14 is rotatably attached by a turning shaft 14a, and can turn around the turning shaft 14a as indicated by an arrow A in the drawing. FIG. 1A shows a case where the leaf spring 14 is located at a retracted position that does not interfere with the insertion / removal of the BGA with respect to the recess 11.
[0017]
Next, a repair work process performed using the jig 10 will be described.
FIG. 3 is a perspective view showing the mother board 20 to be repaired.
Electronic components such as a bare chip 21, QFP 22, and BGA 23 are mounted on the mother substrate 20 made of PWB or the like. The mother board 20 is repaired because an operation failure of the BGA 23 is confirmed by a known quality test method. In the repair in this embodiment, the work proceeds in the order of a removal process of the mounted BGA 23, a solder paste printing process, a mounting process, a reflow process, and a curing process. Note that the order of the removal process and the solder paste printing process may be reversed.
[0018]
FIG. 4A and FIG. 4B are cross-sectional views for explaining the work flow of the removal step.
In FIG. 4A, a plurality of ball electrodes 23a arranged in an array are fixed on the lower surface of the package of the BGA 23 on a mother substrate 20 having a plurality of pads 20a arranged in an array. The mother substrate 20 and the BGA 23 are electrically and mechanically connected to each other by soldering each pad 20a and each ball electrode 23a individually via a solder 24. In order to remove the BGA 23 connected in this way from the mother board 20, first, the solder 24 must be melted to release the solder connection. Therefore, in the removal step, first, the solder 24 is heated and melted by blowing hot air from a hot air nozzle (not shown). Then, as shown in FIG. 4B, the BGA 23 is removed from the mother board 20 by sucking with vacuum tweezers as a conveying member (not shown). After the removal, the solder 24 remaining on the mother board 20 is neatly removed from the mother board 20 by, for example, causing the solder wick to absorb the solder 24 while melting it with a soldering iron.
[0019]
FIG. 5A to FIG. 5C are cross-sectional views for explaining a work flow in a preparation stage of the solder paste printing process performed using the jig 10.
In FIG. 5A, reference numeral 23 denotes a new BGA, and the new BGA has ball electrodes 23a on the lower surface of the package. In the present embodiment, first, the upper surface of the jig 10 (the surface on the side illustrated in FIG. 1A) is prepared so as to face the upper side in the vertical direction. Then, the upper surface of the new BGA 23, that is, the surface opposite to the electrode placement surface (hereinafter referred to as “package upper surface”) is lifted by vacuum tweezers (not shown) by suction force, and the BGA 23 is inserted into the recess 11 of the jig 10 as it is. To do. Thereafter, by releasing the suction to the vacuum tweezers, the BGA 23 is set in the concave portion 11 of the jig 10 as shown in FIG.
[0020]
When the BGA 23 is set in the recess 11 in this way, the leaf spring 14 positioned at the retracted position is rotated around the rotation shaft 14a, and the holding position for pressing the BGA 23 as shown in FIG. 5B. To be located. Due to the pressing force of the leaf spring 14, the BGA 23 in the recess 11 is pressed against the recess bottom surface portion 11b and positioned firmly. After that, as shown in FIG. 5C, the jig 10 in which the BGA 23 is set is turned upside down, thereby setting the printing mask 1 on the lower surface of the jig 10 facing upward in the vertical direction. Specifically, the positioning holes 5 provided at the four corners of the printing mask 1 are inserted into the pins 13 provided at the four corners of the lower surface of the jig 10 to align the printing mask 1 with the lower surface of the jig 10. Here, the diameter of the positioning hole 5 of the printing mask 1 is formed larger than the diameter of the pin 13 of the jig 10. Therefore, in this embodiment, the set printing mask 1 can be slid along the lower surface of the jig 10. With such a configuration, the printing mask 1 is slid and moved so that each ball electrode 23a is positioned directly below each printing hole 4 while visually observing each ball electrode 23a of the BGA 23 through each printing hole 4. Can be combined. When the print mask 1 can be aligned, the leaf spring 15 positioned at the retracted position is rotated around the rotation shaft 15 a and is positioned at a pressing position for pressing the print mask 1. The pressing force of the leaf spring 15 can keep the printing mask 1 from sliding easily. Further, by holding the printing mask 1 with the leaf spring 15, the positioning of the printing mask 1 is almost completed even when performing solder printing on the next BGA 23. Therefore, when performing solder printing on the next BGA 23, the alignment can be completed by simply sliding the printing mask 1 and the work efficiency when performing continuous solder printing on the same type of BGA is improved.
In addition, although it is good also as a structure which fits the positioning hole 5 and the pin 13 exactly, in this case, fine adjustment like this embodiment cannot be performed. Therefore, when the position accuracy of the positioning hole 5 is poor or when the position of the printing hole 4 changes due to environmental change or the like, it is not possible to flexibly cope with it.
[0021]
FIG. 6A to FIG. 6C are cross-sectional views for explaining the work flow of the solder paste printing process.
After the alignment as described above, next, as shown in FIG. 6A, a paste-like solder 24 is placed on the plate surface of the printing mask 1, and then printed on the plate surface with a squeegee 25 to provide solder 24. Is filled in each printing hole 4. Then, as shown in FIG. 6B, the printing mask 1 is peeled off from the jig 10, and the solder 24 in each printing hole 4 is printed on each ball electrode 23a.
[0022]
After the solder 24 is printed on the ball electrode 23a of the BGA 23 in this way, the jig 10 with the BGA 23 set is turned upside down again. Thereby, the jig 10 is in the state shown in FIG. 5A, that is, the upper surface of the jig 10 is directed upward in the vertical direction. Thereafter, the upper surface of the package of the BGA 23 is lifted with vacuum tweezers by suction force, and the BGA 23 is removed from the recess 11 of the jig 10. The BGA 23 removed in this way is transported as it is to a facility for performing the next process while being held by vacuum tweezers.
[0023]
Here, when the jig 10 is placed on the work table in the state shown in FIG. 5A, the package lower surface of the BGA 23 faces the surface of the work table. At this time, in this embodiment, the height of the pin 13 provided on the lower surface of the jig 10 is determined so that the solder 24 on the ball electrode 23a does not contact the surface of the work table. That is, since the height of the pin 13 is higher than the height of the solder 24 printed on the BGA 23 set on the jig 10, the jig 10 is placed on the work table in the state shown in FIG. The solder 24 does not come into contact with the work table even when it is placed on the work table.
[0024]
After the solder paste printing process is completed as described above, the ball electrodes 23a of the BGA 23 are aligned on the pads 20a of the mother substrate 20 by using an alignment device or the like, and the BGA 23 is positioned on the mother substrate 20. Mount (mounting process). Then, the solder 24 printed on the ball electrode 23a is melted by placing the mother substrate 20 in a reflow furnace or blowing hot air from the hot air nozzle between the mother substrate 20 and the BGA 23 (melting step). . Further, the melted solder 24 is hardened by cooling to solder-connect each pad 20a of the mother board 20 and the ball electrode 23a of the BGA 23 (curing process).
[0025]
In the present embodiment, the BGA 23 is locally pressed by the leaf spring 14 in the solder paste printing process. Therefore, a large pressure is applied to the portion of the BGA 23 with which the pressing portion of the leaf spring 14 comes into contact. Therefore, as shown in FIG. 7, the sheet member 30 may be sandwiched between the leaf spring 14 and the upper surface of the BGA 23. Thereby, the pressure added to BGA23 can be disperse | distributed to the whole sheet | seat member.
[0026]
In the present embodiment, the printing mask 1 made of plastic is used, but a printing mask such as a metal mask made of a substrate other than plastic may be used.
In this embodiment, the case of printing solder on the BGA 23 has been described. However, the present invention can also be applied to the case of printing solder on other electronic components such as CSP, LGA, QFP, LSI, bare chip, and the like. .
Further, in the present embodiment, the description is about repair. However, the present invention is not limited to repair, and the printing process using a printing mask is also used when printing solder on an electrode on an electrode arrangement surface of a mounting component such as a BGA for some reason. The present invention can be applied. For example, the present invention can also be applied to a reballing operation for re-forming the ball electrode 23a of the mounted BGA 23 or a new ball electrode 23a formation on a new BGA 23.
[0027]
【The invention's effect】
According to the first to third aspects of the invention, there is an excellent effect that the work after the mounting component is removed from the jig becomes easy.
In particular, according to the invention of claim 2, there is an excellent effect that the pressure applied to the mounted component by the pressing member can be reduced.
[Brief description of the drawings]
FIG. 1A is a front view of a solder printing jig according to an embodiment as viewed from a side where a BGA is set or taken out.
(B) is a back view of the jig.
(C) is sectional drawing of the recessed part periphery provided in the jig | tool.
FIG. 2 is a plan view of a printing mask used for solder printing together with the jig.
FIG. 3 is a perspective view showing a mother board to be repaired.
FIGS. 4A and 4B are cross-sectional views showing a work flow of a removal process.
FIGS. 5A to 5C are cross-sectional views for explaining a work flow in a preparation stage of a solder paste printing process performed using the jig.
6A to 6C are cross-sectional views for explaining a work flow of a solder paste printing process.
FIG. 7 is a sectional view showing a modification of the jig.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Print mask 4 Print hole 5 Positioning hole 10 Jig 11 Recess 11a Opening 11b Recess bottom part 12 Inner wall 13 Pin 14 Leaf spring 20a Pad 23 BGA
23a Ball electrode 25 Squeegee 30 Sheet member

Claims (3)

A holding base in which an opening slightly smaller than the electrode placement surface of the mounting component is formed on the bottom surface of the recess into which the mounting component is inserted;
A holding member for pressing the mounting component inserted into the recess so that the electrode on the electrode arrangement surface is exposed to the opening from the side opposite to the electrode arrangement surface;
A solder printing jig, wherein the pressing member is configured to be movable between a retracted position that does not interfere with the insertion / removal operation of the mounting component with respect to the recess and a pressing position for pressing the mounting component. In the solder printing jig according to claim 1,
A sheet member disposed between the pressing surface of the pressing member and the mounting component, having a larger area than the pressing surface, and having rigidity capable of dispersing the pressing force by the pressing member over the entire area; Solder printing jig characterized by. Inserting the mounting component into a recess having an opening slightly smaller than the electrode arrangement surface of the mounting component on the bottom surface so that the electrode arrangement surface is exposed to the opening,
The mounting component inserted into the recess is pressed from the side opposite to the electrode placement surface by a pressing member,
Cover the electrode placement surface exposed in the opening with a print mask, position the print mask so that the electrode on the electrode placement surface and the print hole of the print mask match, and fill the print hole with solder And
A solder printing method, wherein after removing the printing mask, the pressing member is moved to a position that does not interfere with the operation of taking out the mounting component from the recess, and the mounting component is taken out from the recess.

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