JP2008060209A - Method for manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the processing time in a flux cleaning step. <P>SOLUTION: Flux residues are floated by blowing a cleaning solution obtained by mixing a high-pressure air into a chemical to a plurality of solder balls and a multi-pattern substrate 9 arranged on a first stage 14a rotating in higher velocity, and the multi-piece substrate 9 is moved on a second stage 16a provided in the side of the first stage 14a. Thereafter, the pure water is blown to the plurality of solder balls and the multi-piece substrate 9 arranged on the second stage 16a rotating in higher velocity for cleaning these elements. Accordingly, the cleaning solution and pure water can be supplied uniformly and quickly to the entire part for cleaning fluxes within a short period of time. As a result, the processing time of the flux cleaning process can be shortened. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductor manufacturing technique, and more particularly to a technique effective when applied to the assembly of a semiconductor device having a flux cleaning process.

As an assembly of a small semiconductor device, the plurality of semiconductor chips are sealed together by resin sealing in a state where the back surface of the strip substrate on which the plurality of semiconductor chips are mounted is vacuum-adsorbed to the lower mold of the mold. There is a technique of forming a stop member and then cutting the strip substrate and the sealing member separated from the mold to obtain a plurality of semiconductor devices (see, for example, Patent Document 1).
JP 2002-190488 A

  In a ball mounting process in assembling a semiconductor device such as a CSP (Chip Size Package), a flux is applied to a land of a substrate, and then a ball is mounted and further heat treatment (about 200 ° C.) is performed. Thereby, the ball is cured and the ball mounting is completed. At that time, the flux that has not been contributed to the bonding between the ball and the land remains around the bonding portion of the ball (generation of flux residue). Since the flux contains halogen, if the flux remains on the substrate, migration tends to occur in the wiring. As a result, adjacent wiring patterns become conductive, and short-circuit defects between adjacent wirings are likely to occur.

  Therefore, as a process of removing the flux residue, there is a flux cleaning process shown in the comparative example of FIG. In this flux cleaning step, first, a plurality of substrates are accommodated in a rack 50, and the rack 50 is placed in the first cleaning layer 51 (about 210 seconds). The first cleaning layer 51 contains a cleaning liquid 55 containing an alkaline chemical solution, and thereby the remaining flux is raised.

  Thereafter, the rack 50 is placed in the second cleaning layer 53 containing the pure water 52, and pre-rinsing is performed for about 210 seconds. Subsequently, the rack 50 is placed in the third cleaning layer 54 in which the pure water 52 is accommodated, and rinsing with the pure water 52 is performed for about 210 seconds.

  Thereafter, the rack 50 is taken out from the third cleaning layer 54, and then dried for about 420 seconds to complete the flux cleaning.

  Thus, in the flux cleaning process, it takes a long time to process.

  In addition, since a plurality of cleaning layers are used, a necessary space is large, and the size of the cleaning device cannot be reduced.

  Furthermore, since the cleaning liquid 55 must be supplied to the plurality of first cleaning layers 51 that are large enough to accommodate the rack 50, a large amount of the cleaning liquid 55 is used, which increases the material cost and reduces the manufacturing cost of the semiconductor device. Difficult to do.

  The above-mentioned Patent Document 1 (Japanese Patent Laid-Open No. 2002-190488) discloses a method for assembling a CSP. After a solder bump is fixed to a conductor pattern using a flux, a neutral detergent is used. There is a description to remove the flux residue. However, it does not describe what means is used to clean the flux, but only describes that a neutral detergent is supplied from the solder bump side to remove the flux residue. According to the study of the present inventor, even if the cleaning liquid is supplied to the flux residue, it takes time until the flux residue is melted and emerges from the substrate, so that it is difficult to reduce the cleaning processing time.

  The objective of this invention is providing the technique which can aim at shortening of the processing time in flux washing | cleaning.

  Moreover, the objective of this invention is providing the technique which can attain size reduction of the washing | cleaning apparatus in flux washing | cleaning.

  Furthermore, the objective of this invention is providing the technique which can aim at the reduction of the cost in flux washing | cleaning.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.

  That is, according to the present invention, a cleaning liquid in which high-pressure air is mixed into a chemical liquid is supplied to a plurality of solder balls and a wiring board while rotating the first stage to remove flux residues attached to the solder balls, A process of supplying pure water to a plurality of solder balls and a wiring board while rotating the second stage arranged next to the stage, and cleaning, and drying the solder balls and the wiring board while rotating the second stage And a step of causing

  Of the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

  A cleaning solution in which high-pressure air is mixed into the chemical solution is supplied to the plurality of solder balls and the wiring board while rotating the first stage to remove the flux residue adhering to the solder balls, and is further disposed next to the first stage. By supplying pure water to a plurality of solder balls and wiring boards while cleaning the second stage and cleaning it, the cleaning solution and pure water can be distributed uniformly and quickly throughout the entire process, and flux can be obtained in a short time. Can be washed. Thereby, the processing time of the flux cleaning process can be shortened, and the productivity of the semiconductor device can be improved.

  In addition, since the flux cleaning process is performed in the first stage and the second stage, a large number of cleaning layers are not required. Therefore, the cleaning apparatus can be made compact and the size thereof can be reduced.

  In addition, the processing system can be simplified, the equipment price can be greatly reduced, and the cost in the flux cleaning process can be reduced.

  Further, by reusing and reusing the used chemical solution, the cost for the chemical solution can be reduced, and the cost in the flux cleaning process can be reduced.

  Moreover, the flux cleaning process which considered so that it may not have a bad influence with respect to an environment can be implement | achieved by regenerating and reusing the used chemical | medical solution.

  In the following embodiments, the description of the same or similar parts will not be repeated in principle unless particularly necessary.

  Further, in the following embodiment, when it is necessary for the sake of convenience, the description will be divided into a plurality of sections or embodiments, but they are not irrelevant to each other unless otherwise specified. The other part or all of the modifications, details, supplementary explanations, and the like are related.

  Also, in the following embodiments, when referring to the number of elements (including the number, numerical value, quantity, range, etc.), particularly when clearly indicated and when clearly limited to a specific number in principle, etc. Except, it is not limited to the specific number, and it may be more or less than the specific number.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiments, and the repetitive description thereof will be omitted.

(Embodiment 1)
FIG. 1 is a process flow diagram showing an example of the assembly procedure of the semiconductor device according to the first embodiment of the present invention, and FIG. FIG. 3 is a process flow diagram showing an example of assembly after resin molding in the assembly of the semiconductor device according to the first embodiment of the present invention. 4 is a process flow diagram showing an example of detailed processing in the flux cleaning process of the first embodiment of the present invention, and FIG. 5 is a plan view showing an example of the structure of the cleaning apparatus used in the flux cleaning process shown in FIG. 6 is a cross-sectional view showing the structure of a cross section cut along the line AA shown in FIG. 7, and FIG. 7 is a plan view showing an example of the structure of the first stage provided in the cleaning apparatus shown in FIG. It is. 8 is a cross-sectional view showing a cross-sectional structure cut along the line AA shown in FIG. 9, and FIG. 9 is a plan view showing an example of a structure in which the wiring board is held by the first stage shown in FIG. 10 is a sectional view showing an example of the flux cleaning state in the first stage of the first embodiment of the present invention, and FIG. 11 shows an example of the flux cleaning state in the second stage of the first embodiment of the present invention. It is sectional drawing.

  12 is a cross-sectional view showing the structure cut along the line AA shown in FIG. 13, and FIG. 13 is a plan view showing the structure of the first stage of the modification of the first embodiment of the present invention. 14 is a cross-sectional view showing a cross-sectional structure cut along the line AA shown in FIG. 15, and FIG. 15 is a plan view showing an example of a structure in which the wiring board is supported by the first stage of the modification shown in FIG. It is. Further, FIG. 16 is an enlarged partial sectional view showing an example of a structure to which the flux residue before the flux cleaning of the first embodiment of the present invention is attached, and FIG. 17 shows an example of the structure after the flux cleaning of the first embodiment of the present invention. FIG.

  The semiconductor device of the first embodiment is a resin-sealed small semiconductor package in which a semiconductor chip 1 is mounted on a wiring board. In the first embodiment, as an example, a CSP 7 as shown in FIG. Will be explained. The CSP 7 includes a plurality of solder balls 8 which are external terminals arranged in a grid pattern on the back surface 3b of the wiring board, and further has a size substantially the same as the size of the semiconductor chip 1 to constitute a semiconductor device. ing. Therefore, the basic structure of the CSP 7 is almost the same as that of the BGA type semiconductor package, but can be made smaller than the BGA.

  The structure of the CSP 7 shown in FIG. 3 will be described. The package substrate 3 that is a wiring substrate, the semiconductor chip 1 that is mounted on the main surface 3a of the package substrate 3 and has an integrated circuit, and the pads that are the surface electrodes of the semiconductor chip 1 Conductive wire 4 that electrically connects 1c and bonding terminal 3c of package substrate 3 and solder balls 8 that are a plurality of external terminals provided on a plurality of land portions 3d on back surface 3b of package substrate 3. And a resin body 6.

  The semiconductor chip 1 is made of, for example, silicon, and an integrated circuit is formed on the main surface 1a. The planar shape intersecting with the thickness of the semiconductor chip 1 is a square shape, and in the first embodiment, it is a square. Furthermore, a plurality of pads 1c that are electrically connected to the integrated circuit are formed on the peripheral portion of the main surface 1a. Further, the pads 1 c and the bonding terminals 3 c arranged on the peripheral edge portion of the main surface 3 a of the package substrate 3 are electrically connected by conductive wires 4, respectively. The wire 4 is, for example, a gold wire.

  The semiconductor chip 1 is mounted on the package substrate 3 with the back surface 1b fixed to the package substrate 3 via an adhesive 2 such as a paste agent or a die attach film, and the main surface 1a facing upward. Yes.

  The resin body 6 is made of, for example, an epoxy resin and is formed on the main surface 3a side of the package substrate 3 and seals the semiconductor chip 1 and the plurality of conductive wires 4 with resin.

  Also, the solder balls 8 that are a plurality of external terminals provided on the back surface 3b of the package substrate 3 are made of solder such as Pb-Sn, and are arranged in a grid pattern on the back surface 3b of the package substrate 3.

  The package substrate 3 includes a main surface 3a, a back surface 3b facing the main surface 3a, a plurality of bonding terminals 3c formed on the peripheral edge of the main surface 3a, and a plurality of land portions formed on the back surface 3b. 3d and a plurality of through-hole wirings formed on the main surface 3a and the back surface 3b, and formed between the plurality of bonding terminals 3c and the plurality of land portions 3d, respectively. That is, the plurality of bonding terminals 3c formed on the peripheral edge portion of the main surface 3a are electrically connected to the land portions 3d of the back surface 3b through the corresponding through-hole wirings.

  The planar shape intersecting with the thickness of the package substrate 3 is a square shape, and is a square in the first embodiment.

  The conductor pattern including the bonding terminals 3c and the land portions 3d of the package substrate 3 is made of, for example, a copper alloy, and the plating applied to these conductor patterns is, for example, Ni / Au plating.

  Next, a manufacturing method of the CSP 7 according to the first embodiment will be described with reference to the process flow chart shown in FIG. 1 and the manufacturing process flow charts shown in FIGS.

  First, dicing shown in step S1 of FIG. 1 is performed to obtain a plurality of semiconductor chips 1 from a semiconductor wafer. Each of the plurality of semiconductor chips 1 has a plurality of pads 1c, which are surface electrodes, formed on the periphery of the main surface 1a.

  Further, substrate preparation shown in FIG. 2 is performed. Here, it has a main surface 9a and a back surface 9b opposite to the main surface 9a, and a plurality of device regions (device forming regions) 9d (see FIG. 9) for forming the package substrate 3 are arranged on the main surface 9a. A multi-chip substrate (wiring substrate) 9 is prepared.

  Thereafter, the die bonding shown in step S2 of FIG. 1 and FIG. 2 is performed to fix the semiconductor chip 1 on the device region 9d of the multi-piece substrate 9 via the adhesive 2.

  Thereafter, step S3 in FIG. 1 and wire bonding shown in FIG. 2 are performed. Here, the pads 1c on the main surface 1a of the semiconductor chip 1 and the corresponding electrodes 9c (bonding terminals 3c) of the multi-chip substrate 9 are electrically connected by a conductive wire 4 such as a gold wire. .

  Thereafter, the sheet mold (resin mold in FIG. 2) shown in step S4 is performed. Here, the multi-piece substrate 9 is arranged in the resin molding die 15, and the plurality of device regions 9 d are collectively covered with one cavity 15 a of the resin molding die 15 and sealed with resin. Here, the resin molding die 15 has an upper die in which a recess is formed and a lower die facing the upper die, and the cavity 15a is formed by sandwiching the upper die and the lower die. It is prescribed. That is, the plurality of semiconductor chips 1 and the plurality of wires 4 are collectively covered with one cavity 15 a of the resin molding die 15 and sealed with resin, thereby forming the batch sealing body 5. The sealing resin forming the collective sealing body 5 is, for example, a thermosetting epoxy resin.

  Thereafter, the mark shown in step S5 shown in FIG. 1 (mark in FIG. 3) is performed. Here, the marking 10 is performed by a laser marking method or the like to mark the collective sealing body 5. The marking 10 may be performed by, for example, an ink marking method.

  Thereafter, ball mounting shown in step S6 (ball mounting in FIG. 3) is performed, and the solder balls 8 are connected to the respective land portions 3d of the back surface 9b of the multi-chip substrate 9.

  At that time, flux is applied to each land portion 3d, and then, ball mounting is performed, and further heat treatment (about 200 ° C.) is performed. Thereby, the melted solder ball 8 is cured and the ball mounting is completed. When the ball mounting is performed, as shown in FIG. 16, a flux residue 20 that is a remaining residue of the flux is formed in the vicinity of the joining portion of the solder ball 8.

  Thereafter, flux cleaning shown in step S7 is performed. First, the configuration of the cleaning apparatus 13 shown in FIG. 5 used in the flux cleaning process of the first embodiment will be described.

  The cleaning device 13 includes a chemical cleaning unit 14 that performs chemical cleaning on the ball-mounted multi-piece substrate 9 and a pure water cleaning / drying unit that performs pure water cleaning and drying on the chemical-washed multi-piece substrate 9. A drying unit 16, an unloader 19 for taking out the multi-piece substrate 9 from the pure water cleaning / drying unit 16, and a component transfer hand 17 for transferring the multi-piece substrate 9 are provided.

  Further, the chemical cleaning unit 14 is provided with a first stage 14a that is a spinner that can rotate at high speed, while the pure water cleaning / drying unit 16 also has a second stage 16a that is a spinner that can rotate at high speed. Is provided.

  Thereby, in the chemical cleaning unit 14, as shown in FIG. 10, the cleaning liquid 14g in which high-pressure air is mixed into the chemical liquid is applied to the multi-stage substrate 9 arranged on the first stage 14a. In a state of rotating at a high speed, the solder residue 8 is sprayed (sprayed) from the nozzle 14b onto the solder balls 8 and the multi-piece substrate 9 to remove the flux residue 20 adhering to the vicinity of the joint location of the solder balls 8. In addition, the said chemical | medical solution contained in the cleaning liquid 14g contains an alkaline chemical | drug | medicine, for example.

  On the other hand, in the pure water cleaning / drying unit 16, pure water 16g is rotated at a high speed with respect to the multi-piece substrate 9 disposed on the second stage 16a as shown in FIG. In this state, the solder balls 8 and the multi-chip substrate 9 are sprayed (sprayed) through the nozzle 16b to clean the solder balls 8 and the multi-chip substrate 9. Further, after the cleaning, high-pressure air is supplied to the plurality of solder balls 8 and the multi-piece substrate 9 while the second stage 16a is rotated at a high speed to be dried.

  The component transfer hand 17 is installed so as to be movable in the X, Y, and Z directions, can handle the multi-piece substrate 9 on the first stage 14a, and is also capable of handling the first stage. A large number of substrates 9 can be transferred from 14a onto the second stage 16a.

  Further, in the cleaning device 13, the used chemical solution is regenerated in the chemical cleaning unit 14, and is recycled by, for example, circulating it using a pump or the like. That is, the chemical solution that has been used once is regenerated without being discarded, and then the chemical solution is repeatedly used by being pumped up by a pump or the like and used again.

  Further, the first stage 14a and the second stage 16a are preferably partitioned by a partition plate or the like. That is, since both the first stage 14a and the second stage 16a perform the cleaning process while rotating at high speed, the cleaning liquid 14g scattered by the high-speed rotation of the first stage 14a enters the pure water cleaning / drying unit 16. The first stage 14a and the second stage 16a are partitioned so that the pure water 16g scattered by the high-speed rotation of the second stage 16a does not reach the chemical cleaning unit 14 so as not to reach. It is preferable.

  Further, in the cleaning device 13, the multi-chip substrate 9 is floated during cleaning so that the flux residue 20 attached to the main surface 9 a and the back surface 9 b of the multi-chip substrate 9 as well as the solder balls 8 can be removed. Can be held in.

  Next, the flux cleaning process will be specifically described.

  In the flux cleaning process, first, the loader shown in step S11 of FIG. 4 is performed. That is, the reflow unloader 18 feeds the ball-mounted multi-piece substrate 9 to the chemical cleaning unit 14, and places the multi-piece substrate 9 on the first stage 14 a of the chemical cleaning unit 14. At that time, the multi-substrate 9 is supported by a plurality of substrate support portions 14c on the first stage 14a shown in FIGS.

  As shown in FIGS. 8 and 9, the substrate support portion 14c has a U-shaped tip. As shown in FIG. 8 and FIG. The main surface 9a of the substrate 9 or the collective sealing body 5 is floated and supported so as not to be in contact with the first stage 14a. At this time, the tip of the substrate support portion 14c is not limited to the U-shape, and may be formed in a circular shape since it is sufficient if the multi-piece substrate 9 can be sandwiched. Here, for example, two multi-piece substrates 9 are arranged on one first stage 14a. The multi-chip substrate 9 is arranged with the back surface 9b side (ball mounting surface side) facing upward and the main surface 9a side (collective sealing body 5 side) facing downward.

  Thereafter, chemical cleaning shown in step S12 of FIG. 4 is performed on the first stage 14a. At the time of cleaning, as shown in FIG. 10, the nozzle 14b is disposed on the back surface 9b side (upper side) of the multi-chip substrate 9, and the lower nozzle 14d is disposed on the main surface 9a side (lower side). The surface 9a is cleaned by supplying the cleaning liquid 14g from the nozzle 14b and the lower nozzle 14d.

  Note that a chemical liquid supply system 14e and an air supply system 14f are connected to the nozzle 14b and the lower nozzle 14d, respectively, and a cleaning liquid 14g obtained by mixing high-pressure air into the chemical liquid can be discharged from the nozzle 14b and the lower nozzle 14d, respectively. It has a simple structure.

  Thereafter, the first stage 14a is rotated at a high speed, and a cleaning solution 14g in which high-pressure air is mixed with a chemical solution containing an alkaline chemical is supplied from the nozzle 14b and the lower nozzle 14d while the first stage 14a is rotated at a high speed. By spraying (spraying) the solder balls 8 and the multi-piece substrate 9, the flux residue 20 adhering to the vicinity of the joints of the solder balls 8 is removed as shown in FIG. 16 (first cleaning step).

  At that time, as shown in FIG. 10, it is preferable to discharge the cleaning liquid 14g radially from the nozzle 14b and the lower nozzle 14d. By discharging the cleaning liquid 14g radially, it becomes possible to supply the cleaning liquid 14g to all the solder balls 8 and over the entire surface of the substrate, and the flux residue 20 can be reliably removed.

  Further, the flux residue 20 does not always remain only on the ball mounting surface side. For example, when a plurality of solder balls 8 are erroneously mounted on one land, for example, alcohol is supplied to the joint portion of the solder balls 8 and the balls are attached again. At this time, there is a possibility that the flux component dissolved by the alcohol wraps around the surface side of the collective sealing body 5. However, as in the first embodiment, since the flux cleaning process is performed in a state where the multi-piece substrate 9 is floated, the main surface 9a side (downward side) of the multi-piece substrate 9 is also provided from the lower nozzle 14d. It is possible to spray (spray) the cleaning liquid 14g, and it is possible to remove the flux residue 20 that has adhered to the main surface 9a side (downward side) of the multi-chip substrate 9 and has adhered.

  Thereafter, the multi-piece substrate 9 is transferred onto the rotatable second stage 16a arranged beside the first stage 14a. That is, the multi-piece substrate 9 on the first stage 14a of the chemical cleaning unit 14 is handled by the component transfer hand 17, and then the second stage 16a of the pure water cleaning / drying unit 16 shown in FIG. A large number of substrates 9 are transferred.

  On the second stage 16a, as in the case of the first stage 14a, for example, two multi-piece substrates 9 are placed with their back surfaces 9b (ball mounting surface side) facing upward and the main stage 9a. The surface 9a side (resin body 6 side) is directed downward, and the multi-piece substrate 9 is sandwiched between the outer peripheral portions by the substrate support 16c, and the main surface 9a of the multi-piece substrate 9 or the collective sealing body 5 Is supported so as to be in non-contact with the second stage 16a.

  Thereafter, pure water cleaning shown in step S13 in FIG. 4 is performed on the second stage 16a. At the time of cleaning, as shown in FIG. 11, the nozzle 16b is disposed on the back surface 9b side (upper side) of the multi-chip substrate 9, and the lower nozzle 16d is disposed on the main surface 9a side (lower side). The surface 9a is cleaned by spraying (spraying) pure water 16g from the nozzle 16b and the lower nozzle 16d (second cleaning step).

  A pure water supply system 16e and an air supply system 16f are connected to the nozzle 16b and the lower nozzle 16d, respectively, so that pure water 16g or high-pressure air can be discharged from the nozzle 16b and the lower nozzle 16d, respectively. It has become.

  Thereafter, the second stage 16a is rotated at a high speed, and in this state, pure water 16g is supplied from the nozzle 16b and the lower nozzle 16d to the plurality of solder balls 8 and the multi-piece substrate 9, thereby The solder balls 8 and the multi-chip substrate 9 are washed away with 16 g of pure water.

  At that time, it is preferable to discharge 16 g of pure water radially from the nozzle 16b and the lower nozzle 16d as shown in FIG. By discharging 16 g of pure water radially, it becomes possible to supply 16 g of pure water to all the solder balls 8 and over the entire surface of the substrate, and the solder balls 8 and the multi-piece substrate 9 are sufficiently washed away. (Rinse).

  After the cleaning with 16 g of pure water, the drying shown in step S14 in FIG. 4 is performed. Here, the solder balls 8 and the multi-piece substrate 9 are dried while rotating the second stage 16a at a high speed. That is, by stopping the discharge of pure water 16g and switching the discharge from the nozzle 16b and the lower nozzle 16d to high-pressure air, the solder ball 8 and the multi-piece substrate 9 are dried while rotating the second stage 16a at a high speed. It becomes possible to make it.

  Thereby, the cleaned multi-chip substrate 9 shown in FIG. 17 from which the flux residue 20 has been removed can be obtained. Thereafter, the unloader shown in step S15 of FIG.

  Thereby, the flux cleaning process of step S7 shown in FIG. 1 is completed.

  As shown in the modified examples of FIGS. 12 and 13, as a mechanism for supporting the multi-piece substrate 9 on the first stage 14a (the same applies to the second stage 16a), the upper end of the substrate support portion 14c is used. It may have a groove-like recess 14h. That is, as shown in FIGS. 14 and 15, the multi-piece substrate 9 is accommodated in the recess 14h at the upper end of the substrate support portion 14c, and the multi-piece substrate 9 is pressed by the claw portion 14i so as not to jump out. Thus, the removal of the flux residue 20 with the cleaning liquid 14 g or the cleaning with 16 g of pure water may be performed. As shown in FIG. 13, a plurality of through holes 14 j are formed in the recess 14 h so that the cleaning liquid 14 g and pure water 16 g from the lower side reach the solder balls 8 and the multi-piece substrate 9.

  Further, as shown in FIG. 5, when the multi-substrate 9 (first wiring board) is cleaned and dried on the second stage 16a of the pure water cleaning / drying unit 16, the chemical cleaning unit is simultaneously performed. It is preferable that the other multi-piece substrate 9 (second wiring board) is cleaned with the cleaning liquid 14g on the 14 first stages 14a.

  That is, the first multi-chip substrate 9 after the removal of the flux residue 20 in the first stage 14a is transferred onto the second stage 16a, and then the second multi-chip substrate 9 is transferred to the reflow unloader. 18 is sent onto the first stage 14a. Thereby, the flux residue 20 by the cleaning of the first multi-chip substrate 9 on the second stage 16a with the pure water 16g and the cleaning liquid 14g of the second multi-chip substrate 9 on the first stage 14a. Are simultaneously performed. The same applies to the third and subsequent multi-chip substrates 9.

  As a result, the efficiency of the flux cleaning process performed in the cleaning device 13 can be improved.

  After completion of the flux cleaning, individualization shown in FIG. 3 is performed. That is, the flux-cleaned multi-piece substrate 9 is cut into individual semiconductor devices (CSP 7). Here, first, tape affixing shown in step S8 of FIG. 1 is performed. That is, as shown in the individualization of FIG. 3, the dicing tape 12 is pasted on the surface of the collective sealing body 5 formed by a resin mold.

  Thereafter, package dicing (tape type) shown in step S9 of FIG. 1 is performed. That is, as shown in the individualization of FIG. 3, it is cut by the dicing blade 11 while being fixed by the dicing tape 12 and is divided into individual CSPs 7.

  Thereby, the assembly of the CSP 7 is completed and the product is completed.

  In the individualization step, jig-type package dicing may be performed in which a large number of substrates 9 are accommodated in the dicing jig shown in step S10 of FIG.

  Further, in the ball mounting process of step S6, solder is applied to the land portions 3d of the multi-chip substrate 9, and then the solder balls 8 are formed by a reflow process. For this reason, even in the ball mounting process, there arises a problem that the multi-chip substrate 9 is further warped by this reflow process. In the marking process, marking is performed by a laser marking method or the like. However, when the package substrate 3 is warped, it is difficult to irradiate the surface of the batch sealing body 5 with a laser beam vertically. Marking defect that the mark is not attached to the surface of the sheet occurs.

  Therefore, as in the first embodiment, by performing ball mounting after marking, before performing the reflow processing at the time of forming the solder balls 8 which is one of the factors that warp the multi-chip substrate 9, By performing the mark process first, marking defects can be suppressed.

  However, the step of marking the collective sealing body 5 may be performed after the ball mounting step.

  According to the method of manufacturing the semiconductor device of the first embodiment, the cleaning liquid 14g obtained by mixing high-pressure air into the chemical liquid is sprayed and cleaned on the solder balls 8 and the multi-piece substrate 9 while rotating the first stage 14a. Further, by rotating the second stage 16a disposed beside the first stage 14a and supplying the pure water 16g to the solder balls 8 and the multi-piece substrate 9 for cleaning, the cleaning liquid 14g and the pure water 16g are supplied. It can be distributed evenly and quickly throughout. Furthermore, since the centrifugal force generated by the rotating operation is applied to the flux residue 20, it is possible to float the flux residue 20 and fly it.

  That is, the cleaning apparatus 13 of the first embodiment has two stages, a first stage 14a and a second stage 16a, and high-speed rotation processing of each stage, two-fluid cleaning with a chemical solution and high-pressure air, Therefore, a large number of chemicals can be taken and distributed over the entire surface of the substrate 9 almost uniformly and at high speed.

  As a result, the flux can be cleaned in a short time.

  Thereby, the processing time of a flux washing process can be shortened and productivity of CSP7 (product) can be improved.

  Furthermore, since the flux residue 20 that has been floated by spraying the cleaning liquid 14g is repelled by the centrifugal force during high-speed rotation of the first stage 14a, the cleaning effect of the flux can be further increased.

  Since the first stage 14a and the second stage 16a are partitioned by a partition plate or the like, the pure water 16g scatters during the high-speed rotation of the second stage 16a and jumps onto the first stage 14a. It is possible to prevent 16 g of pure water from being mixed with 14 g of the cleaning liquid. When 16 g of pure water is mixed with 14 g of the cleaning liquid, the cleaning effect is reduced, so that this reduction in the cleaning effect can be prevented. This is possible because the cleaning device 13 has two stages, and cannot be realized unless it has only one stage.

Further, since the cleaning apparatus 13 performs the flux cleaning process in the first stage and the second stage, it does not require a large number of cleaning layers as shown in the comparative example of FIG. As a result, the cleaning device 13 can be made compact and downsized. For example, in the case of the cleaning apparatus 13 of the first embodiment shown in FIG. 5, the apparatus size can be reduced by about 6 m ² compared to the cleaning system of the comparative example having a large number of cleaning layers in FIG.

  In the cleaning device 13, the processing system can be simplified, and the equipment price can be greatly reduced. As a result, cost reduction in the flux cleaning process can be achieved.

  Further, in the first cleaning step using the first stage 14a, the used chemical solution is regenerated, circulated and reused, so that the cost related to the chemical solution can be reduced. Reduction can be achieved.

  Further, by reusing and reusing the used chemical solution, it is possible to realize a flux cleaning process in consideration of not adversely affecting the environment.

  Further, the holding of the multi-piece substrate 9 in each stage of the cleaning device 13 is not vacuum suction, but has a structure in which the end portion of the substrate is mechanically held (clamped). This is because the multi-piece substrate 9 has a problem of warping. That is, since the multi-cavity substrate 9 is relatively hard, it is difficult to follow the surface of the stage during vacuum evacuation and the vacuum may leak. Therefore, in the cleaning apparatus 13 according to the first embodiment, the multi-piece substrate 9 is fixed on each stage not by vacuum suction but by mechanical means.

(Embodiment 2)
18 is a plan view showing an example of the structure of a dicer used in the package dicing process according to the second embodiment of the present invention. FIG. 19 is a perspective view showing an example of a package dicing process using the dicer shown in FIG. FIG. 19 is a partial cross-sectional view showing an example of a flux cleaning process after package dicing using the dicer shown in FIG. 18.

  In the second embodiment, in order to efficiently perform flux cleaning, in the package dicing process, flux cleaning is also performed at the time of cleaning for removing the cutting waste after cutting, thereby omitting the flux cleaning process. is there. That is, in the assembly of the CSP 7 shown in FIG. 1, the flux cleaning process in step S7 is omitted by performing the flux cleaning process in step S7 together in the package dicing process in step S9.

  The configuration of the dicer 21 shown in FIG. 18 will be described. The dicing part 21a for performing package dicing, the cleaning stage 21b for washing away the cutting waste and the flux residue 20, and the adhesive strength of the dicing tape 12 by irradiating UV (Ultraviolet). It has a UV irradiation part 21c for lowering and a loader part 21d for accommodating the multi-piece substrate 9.

  This dicer 21 is used to perform flux cleaning together with cleaning of the cutting waste after cutting in the package dicing process. That is, after the ball mounting in step S6 of FIG. 1 is completed, tape sticking in step S8 is performed, and then package dicing in step S9 is performed.

  First, as shown in FIG. 19, the multi-piece substrate 9 is attached to the dicing tape 12 fixed to the ring-shaped jig 22 by applying the tape in step S <b> 8. Further, the ring-shaped jig 22 is fixed to the dicing stage 23 arranged in the dicing part 21a by vacuum suction.

  Thereafter, the multi-piece substrate 9 is cut by the dicing blade 11 on the dicing stage 23 and separated into individual semiconductor devices (CSPs 7).

  Thereafter, package dicing shown in step S9 of FIG. 1 is performed. First, the separated semiconductor device (CSP 7) is maintained on the dicing tape 12 and placed on the rotatable cleaning stage 21b provided in the dicer 21, and attached to the dicing tape 12. The semiconductor device (CSP 7) is cleaned in the attached state.

  At the time of cleaning, as shown in FIG. 20, a cleaning solution 25 in which high-pressure air is mixed into a chemical solution is sprayed to the CSP 7 through a nozzle 24 while rotating the cleaning stage 21b at a high speed, so that the solder balls 8 and the package substrate 3 are removed. Clean (ball surface flux cleaning).

  Thereafter, pure water 26 is sprayed onto the CSP 7 through the nozzle 24 while rotating the cleaning stage 21b at a high speed on the cleaning stage 21b to clean the solder balls 8 and the package substrate 3 (ball surface cleaning). High pressure air 27 is blown from 24 to dry (ball surface drying).

  As described above, in the second embodiment, in the package dicing step, the cutting waste formed at the time of cutting is washed away and the flux is washed together. By cleaning the flux, the flux residue 20 adhering to the solder ball 8 joint as shown in FIG. 16 can be removed as shown in FIG.

  According to the method of manufacturing the semiconductor device of the second embodiment, the flux cleaning process that is performed independently in the assembly process of the CSP 7 is performed together with the cleaning in the package dicing process, thereby omitting the flux cleaning process. It is possible to improve the assembly efficiency of the semiconductor device (CSP 7).

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiments of the invention. However, the present invention is not limited to the embodiments of the invention, and various modifications can be made without departing from the scope of the invention. It goes without saying that it is possible.

  For example, in the first embodiment, the case where cleaning is performed by rotating the stage during flux cleaning has been described. However, the nozzle may be rotated without rotating the stage, thereby simplifying the mechanism of the cleaning apparatus. Can be

  Further, the operation of the stage at the time of flux cleaning is not limited to the rotation operation, and may be an operation such as repetitive linear movement. That is, the stage may be rotated or linearly moved as long as the cleaning liquid 14g and pure water 16g are sprayed onto the solder balls 8, the multi-chip substrate 9 and the like uniformly and at high speed.

  The present invention is suitable for assembling an electronic device that performs flux cleaning.

It is a process flow figure showing an example of an assembly procedure of a semiconductor device of Embodiment 1 of the present invention. It is a manufacturing process flowchart which shows an example of the assembly to the resin mold in the assembly of the semiconductor device of Embodiment 1 of this invention. It is a manufacturing process flowchart which shows an example of the assembly after the resin mold in the assembly of the semiconductor device of Embodiment 1 of this invention. It is a process flow figure showing an example of detailed processing in a flux washing process of Embodiment 1 of the present invention. It is a top view which shows an example of the structure of the washing | cleaning apparatus used at the flux washing | cleaning process shown in FIG. It is sectional drawing which shows the structure of the cross section cut | disconnected along the AA line shown in FIG. It is a top view which shows an example of the structure of the 1st stage provided in the washing | cleaning apparatus shown in FIG. It is sectional drawing which shows the structure of the cross section cut | disconnected along the AA line shown in FIG. It is a top view which shows an example of the structure which clamped the wiring board by the 1st stage shown in FIG. It is sectional drawing which shows an example of the flux washing state in the 1st stage of Embodiment 1 of this invention. It is sectional drawing which shows an example of the flux washing state in the 2nd stage of Embodiment 1 of this invention. It is sectional drawing which shows the structure cut | disconnected along the AA line shown in FIG. It is a top view which shows the structure of the 1st stage of the modification of Embodiment 1 of this invention. It is sectional drawing which shows the structure of the cross section cut | disconnected along the AA line shown in FIG. It is a top view which shows an example of the structure which supported the wiring board by the 1st stage of the modification shown in FIG. It is an expanded partial sectional view which shows an example of the structure where the flux residue before the flux cleaning of Embodiment 1 of this invention adhered. It is an expanded partial sectional view which shows an example of the structure after the flux washing | cleaning of Embodiment 1 of this invention. It is a top view which shows an example of the structure of the dicer used at the package dicing process of Embodiment 2 of this invention. It is a perspective view which shows an example of the package dicing process using the dicer shown in FIG. It is a fragmentary sectional view which shows an example of the flux washing process after the package dicing using the dicer shown in FIG. It is a process flow figure showing the processing procedure in the flux washing process of a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor chip 1a Main surface 1b Back surface 1c Pad (surface electrode)
2 Adhesive 3 Package board (wiring board)
3a main surface 3b back surface 3c bonding terminal 3d land portion 4 wire 5 collective sealing body 6 resin body 7 CSP (semiconductor device)
8 Solder balls 9 Multiple substrate (wiring board)
9a Main surface 9b Back surface 9c Electrode 9d Device region (device formation region)
DESCRIPTION OF SYMBOLS 10 Marking 11 Dicing blade 12 Dicing tape 13 Cleaning apparatus 14 Chemical cleaning part 14a First stage 14b Nozzle 14c Substrate support part 14d Lower nozzle 14e Chemical liquid supply system 14f Air supply system 14g Cleaning liquid 14h Recess 14i Claw part 14j Through-hole 15 Resin Mold 15a Cavity 16 Pure water cleaning / drying section 16a Second stage 16b Nozzle 16c Substrate support section 16d Lower nozzle 16e Pure water supply system 16f Air supply system 16g Pure water 17 Parts transfer hand 18 Reflow unloader 19 Unloader 20 Flux residue 21 Dicer 21a Dicing part 21b Cleaning stage 21c UV irradiation part 21d Loader part 22 Ring-shaped jig 23 Dicing stage 24 Nozzle 25 Cleaning liquid 26 Pure water 27 High-pressure air 50 Rack 5 First wash layer 52 of pure water 53 second wash layer 54 third cleaning layer 55 washing solution

Claims (16)

(A) A wiring board on which a plurality of solder balls are mounted is arranged on a rotatable first stage, and the plurality of solder balls are rotated while rotating the first stage with a cleaning liquid in which high-pressure air is mixed into a chemical solution. And a first cleaning step for removing the flux residue that is supplied to the wiring board and adhered to the solder balls;
(B) After the step (a), the step of transferring the wiring board onto a rotatable second stage disposed beside the first stage;
(C) a second cleaning step of cleaning the solder balls and the wiring board by supplying pure water to the plurality of solder balls and the wiring board while rotating the second stage on the second stage;
(D) After the step (c), the method further comprises the step of drying the solder balls and the wiring board while rotating the second stage.   2. The method of manufacturing a semiconductor device according to claim 1, wherein in the first cleaning step, the used chemical solution is regenerated, circulated and reused.   2. The semiconductor device manufacturing method according to claim 1, wherein the cleaning liquid or the pure water is sprayed from a nozzle disposed on each stage in each of the steps (a) and (c). Manufacturing method.   4. The method of manufacturing a semiconductor device according to claim 3, wherein the cleaning liquid or the pure water is discharged radially from the nozzle.   2. The method of manufacturing a semiconductor device according to claim 1, wherein the first stage and the second stage are partitioned and arranged.   2. The method of manufacturing a semiconductor device according to claim 1, wherein in the step (a) and the step (c), at the time of cleaning, the wiring substrate is sandwiched between outer peripheral portions, and a main surface or a back surface of the wiring substrate is A method of manufacturing a semiconductor device, wherein the semiconductor device is cleaned while being supported in a non-contact manner with the first or second stage.   2. The method of manufacturing a semiconductor device according to claim 1, wherein, in the step (a) and the step (c), nozzles are respectively disposed on a main surface side and a back surface side of the wiring board during the cleaning, A method of manufacturing a semiconductor device, wherein the cleaning liquid or the pure water is supplied to the back surface for cleaning.   2. The method of manufacturing a semiconductor device according to claim 1, wherein in the step (a) and the step (c), the wiring board is accommodated in a recess formed on each stage and cleaned during the cleaning. A method of manufacturing a semiconductor device.   2. The method of manufacturing a semiconductor device according to claim 1, wherein when the first wiring board is washed with pure water on the second stage, the second wiring board is simultaneously placed on the first stage. A method for manufacturing a semiconductor device, comprising cleaning with a cleaning liquid.   2. The method of manufacturing a semiconductor device according to claim 1, wherein the chemical liquid of the cleaning liquid contains an alkaline chemical. (A) a step of preparing a multi-chip substrate having a main surface and a back surface opposite to the main surface, wherein a plurality of device forming regions are formed on the main surface;
(B) mounting a semiconductor chip in a device formation region of the multi-cavity substrate;
(C) electrically connecting the electrode of the multi-chip substrate and the surface electrode of the semiconductor chip with a conductive wire;
(D) covering the plurality of device forming regions with one cavity of a resin molding die and resin-sealing the semiconductor chip and the wire;
(E) providing a plurality of solder balls on the back surface of the multi-cavity substrate;
(F) Arranging a large number of substrates on which a plurality of solder balls are mounted on a rotatable first stage, and cleaning the liquid in which high-pressure air is mixed with a chemical solution while rotating the first stage. Supplying the solder balls and the multi-piece substrate through a nozzle to remove the flux residue adhering to the solder balls;
(G) After the step (f), the wiring board is transferred onto a rotatable second stage disposed beside the first stage, and then, on the second stage, the first stage Cleaning the solder balls and the multi-chip substrate by supplying pure water to the plurality of solder balls and the multi-chip substrate through a nozzle while rotating the stage of 2;
(H) a method of manufacturing a semiconductor device, comprising the step of cutting the multi-piece substrate and dividing it into individual semiconductor devices.   12. The method of manufacturing a semiconductor device according to claim 11, wherein the first stage and the second stage are arranged in a partitioned manner.   12. The method of manufacturing a semiconductor device according to claim 11, wherein the cleaning liquid or the pure water is discharged radially from the nozzle.   12. The method of manufacturing a semiconductor device according to claim 11, wherein the chemical liquid of the cleaning liquid contains an alkaline chemical. (A) a step of preparing a multi-chip substrate having a main surface and a back surface facing the main surface, wherein a plurality of device forming regions are formed on the main surface;
(B) mounting a semiconductor chip in a device formation region of the multi-cavity substrate;
(C) electrically connecting the electrode of the multi-chip substrate and the surface electrode of the semiconductor chip with a conductive wire;
(D) covering the plurality of device formation regions with one cavity of a resin molding die and resin-sealing the semiconductor chip and the wire;
(E) providing a plurality of solder balls on the back surface of the multi-cavity substrate;
(F) cutting the multi-cavity substrate by a dicer and dividing it into individual semiconductor devices;
(G) The separated semiconductor device is arranged on a rotatable stage provided in the dicer, and a cleaning liquid in which high-pressure air is mixed with a chemical solution is placed in the semiconductor device while rotating the stage. The solder ball and the wiring board are supplied to be cleaned, and after the cleaning, pure water is supplied to the semiconductor device through a nozzle while rotating the stage on the stage, and the solder ball and the wiring board are cleaned. A step of cleaning the wiring board,
In the step (g), the flux used in the step (e) and the cutting waste formed in the step (f) are washed away.   16. The method of manufacturing a semiconductor device according to claim 15, wherein the multi-cavity substrate to which a dicing tape is attached is cut in the step (f), and then separated into pieces in the step (g). A method of manufacturing a semiconductor device, comprising: placing the semiconductor device on the stage in a state of being affixed to the dicing tape; and cleaning the semiconductor device in a state of being affixed to the dicing tape.

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