JP5766587B2 - Electroless plating equipment - Google Patents

Description

  The present invention relates to an electroless plating apparatus, and in particular, an electroless plating apparatus capable of stably performing uniform processing on the surface of a substrate such as a semiconductor wafer while employing a highly productive batch processing method. About.

  For example, as shown in FIG. 1, for example, as shown in FIG. 1, the micro bump 12 provided at a predetermined position of the CPU 10 and the micro bump 16 provided at a predetermined position of the memory 14 are both electrodes as the three-dimensional mounting for electrically connecting the semiconductor chips. It is proposed that the microbumps (electrodes) 12 and 16 are joined to each other.

  The micro bumps 16 provided in the memory 14 are made of, for example, Cu—Sn. For example, the microbump 12 provided in the CPU 10 has a Ni plating film 20 of 2 to 10 μm formed on the surface of the bump pad 18 made of, for example, Al or Cu, and the surface of the Ni plating film 20 has a thickness of 50 to 200 nm, for example. An Au plating film 22 is formed. The Au plating film 22 diffuses into the micro bumps 16 made of, for example, Cu—Sn when the micro bumps 12 and 16 are joined. Therefore, the Au plating film 22 itself does not affect the bonding, but has a role of preventing the oxidation of the surface of the Ni plating film 20 and maintaining the bonding strength.

  Also in TSV (Through Silicon Via) wiring connection, as shown in FIG. 2, the surface bump 36 formed by sequentially laminating the Ni plating film 32 and the Au plating film 34 on the surface side of the TSV 30, and the back surface of the TSV 30 It has been proposed to join the back bumps 38 formed on the side.

  As a technique for forming the Ni plating films 20 and 32 and the Au plating films 22 and 34 as described above, the use of electroless plating instead of electrolytic plating has been studied. Further, in addition to Ni and Au, in the case of plating films made of simple materials and composite materials such as Co, Pd, Pt, Cu, Sn, Ag, Rh, and Ru that can be electrolessly plated, instead of electrolytic plating. Adoption of electroless plating has been studied.

  As the base metal (bump pad 18) of the micro bump 12 shown in FIG. Al and Cu are not catalytic metals such as Fe, Co, Ni, Pd, Pt and the like. For this reason, as a pretreatment for plating, a zincate process is generally performed when the base metal is Al, and a Pd catalyst application process (or initial energization) is performed when the base metal is Cu. In the zincate treatment on the Al surface, zinc is generally applied to the Al surface by displacement plating. In the electroless plating, zinc is replaced with a catalyst metal that can be electrolessly plated.

  Electroless plating equipment is generally classified into electroless plating equipment that employs a single wafer processing system that processes substrates one by one and electroless plating equipment that employs a batch processing system that holds and processes multiple substrates simultaneously. Broadly divided. The plating rate of electroless plating is generally 1 to 20 μm / s, which is much slower than the plating rate of electrolytic plating. For this reason, when applying electroless plating to a process that requires a great amount of time such as bump formation, it is common to consider a batch processing method rather than a single wafer processing method.

  The batch processing type electroless plating apparatus has an advantage that the throughput in the same footprint is very high as compared with the single wafer processing type. However, the batch processing type electroless plating apparatus is designed to process a plurality of substrates held in parallel in the vertical direction by simultaneously immersing them in a processing solution such as a plating pretreatment solution or a plating solution, For this reason, the amount of metal consumed in one batch process, for example, in the plating solution is generally large, and the amount of chemical solution, pure water, etc. that adheres to the substrate and is taken outside is generally large. Further, for example, it is necessary to perform flushing for removing deposits adhering to the inside of the plating solution circulation line or the like with an etching solution or the like quite frequently.

  Here, in electroless plating using a batch processing method, metal supply based on the metal consumption calculated based on the area of the surface to be plated and the plating time, and metal based on the results of periodic plating solution analysis The operation of the plating solution by replenishing is generally performed. For example, the expected replenishment of metal ions for each batch and the replenishment of metal ions by analyzing the plating solution once every few days, and when the amount of deposited metal reaches a certain value, I try to exchange.

  As a substrate processing apparatus adopting a batch processing method, the applicant applies a substrate holder for holding a plurality of substrates and immersing them in a processing solution in the processing tank, and a processing liquid in the processing tank while holding the plurality of substrates. The thing which was made to rotate in is proposed (refer patent document 1). Moreover, as a substrate processing apparatus adopting a batch processing method, a carrier mounting unit, a horizontal transfer robot, a posture changing mechanism, a pusher, a transport mechanism, and a substrate processing unit are provided so that a plurality of substrates can be processed while being transported simultaneously. What has been proposed has been proposed (see Patent Document 2).

JP 2009-57593 A Japanese Patent No. 3974985

  As an electroless plating apparatus that performs electroless plating using a batch processing method, a single transfer robot that holds a plurality of substrates in the vertical direction and runs in the horizontal direction, and is arranged along the running direction of the transfer robot The plurality of processing tanks are provided, and the plurality of substrates held by the transport robot are transported while being held by the transport robot, and the plurality of substrates held by the transport robot are immersed in the processing liquid in the processing tank and sequentially processed. What is made is generally known. It is also widely performed to transport a substrate carrier on which a plurality of substrates are mounted in the vertical direction by a transport robot.

  However, when a plurality of substrates are transferred using a single transfer robot or substrate carrier and processed by immersing them in the processing solution in the processing tank, for example, the amount of the chemical solution taken out from each chemical solution tank is large. For this reason, the time for the water washing treatment in the next process becomes longer, and the amount of pure water used in the next process increases, resulting in a decrease in throughput and an increase in cost.

  In addition, in an electroless plating apparatus that performs electroless plating using a batch processing method, for example, flushing for removing deposits adhering to the inside of a plating solution circulation line with an etching solution or the like is required quite frequently. It has been strongly desired to develop an electroless plating apparatus that can easily and quickly carry out the process.

  In addition, if a plating solution is used that replenishes the plating solution with metal based on prospects and periodic analysis, it is difficult to grasp the state of the plating solution immediately before plating, and the metal concentration of the plating solution is adjusted to the metal. Even if it is corrected by the above, it does not take into account the state of the plating equipment, so the fluctuation of the plating film thickness is large due to unexpected deposition of metal during plating, etc. There was a decrease.

  The present invention has been made in view of the above circumstances, and while adopting a highly productive batch processing method, the amount of chemical solution containing the plating solution is reduced to reduce the cleaning time in the cleaning process, and further, plating. Flushing of the inside of the liquid circulation line etc. can be performed easily and quickly. Furthermore, it is possible to judge the state of the plating solution and the state of the plating apparatus, and to manage the plating solution with a stable and long life. An object is to provide an electroless plating apparatus.

  The invention described in claim 1 is a pre-plating bath for performing pre-plating treatment, a water-washing bath for washing the substrate after the pre-plating treatment, and a plurality of substrates being supported and conveyed below the substrate therebetween. A plating pretreatment module having a substrate holder, a plating bath for performing electroless plating on the substrate surface after the plating pretreatment, a water washing bath for washing the substrate after electroless plating, and a plurality of substrates below them A plating module having a substrate holder for supporting and transporting, and an inter-module substrate transporting device for gripping and transporting a plurality of substrates from above between the plating pretreatment module and the plating module; The tank has a plating pretreatment liquid circulation line having a temperature adjustment function of the plating pretreatment liquid, and the plating tank has a plating liquid circulation line having a temperature adjustment function of the filter and the plating liquid. Has a down, the plating solution circulation line is an electroless plating apparatus characterized by being connected to a flushing line for flushing the interior of the plating solution circulation line, and the plating tank.

  Thus, by providing a substrate holder for each module, the configuration of the substrate holder is further simplified, the amount of the chemical solution containing the plating solution is reduced to the outside, and the cleaning time in the cleaning process is also reduced. Throughput can be reduced and throughput can be improved. In addition, flushing with an etching solution or the like in the plating solution circulation line and the plating tank can be easily and quickly performed through a flushing line connected to the plating solution circulation line.

The invention according to claim 2 is the electroless plating apparatus according to claim 1, wherein the plating pretreatment is a zincate treatment on an Al surface, and the plating pretreatment bath is a zincate treatment bath.
When electroless plating is performed on the copper surface, for example, a Pd catalyst application treatment is performed as a pretreatment for plating.

  The invention according to claim 3 is the electroless plating according to claim 1 or 2, wherein the washing tank of the plating module has a chemical solution supply line for supplying a chemical solution for removing an oxide film on the surface of the plating film. Device.

According to a fourth aspect of the present invention, at least one of the pre-plating tank and the water washing tank of the pre-plating module and the water washing tank of the plating module has a QDR function. The electroless plating apparatus according to any one of Items 1 to 3.
Thus, by providing a QDR (Quick Dump Rinse) function, the substrate surface can be sufficiently rinsed (washed) in a short time, and the apparatus can be made compact and compact.

The invention described in claim 5 is characterized in that the pre-plating module and the plating module are accommodated in a housing having an air conditioning function for using air as a down flow. it is an electroless plating apparatus according to an item.

The invention of claim 6 is the electroless plating apparatus according to any one of claims 1 to 5, characterized in that it comprises a drying unit for drying the substrate was washed with water after the plating.

  The invention according to claim 7 is the electroless plating apparatus according to any one of claims 1 to 6, further comprising a temporary placement station for temporarily placing a plurality of substrates before processing.

  In the invention according to claim 8, the plating tank measures the metal concentration of the plating solution immediately before plating and the metal concentration of the plating solution immediately after plating, and calculates the amount of deposited metal from the difference between these metal concentrations, 8. A replenishing liquid replenishing device that compares the amount of deposited metal with a target value and replenishes a replenishing liquid that has been corrected to a predetermined metal concentration according to the amount of deposited metal. It is an electroless-plating apparatus as described in any one of these.

  In this way, the plating solution is operated with accurate judgment of the state of the plating solution and the state of the plating apparatus, and it is possible to prevent the plating apparatus from malfunctioning and damaging the product while reducing the fluctuation range of the plating film thickness. It can be kept small and can cope with an unexpected decrease in plating rate.

  The invention according to claim 9 is characterized in that when the number of corrections for correcting the metal concentration of the replenisher exceeds the number of corrections set in advance, the reconstruction bath is performed. Device.

  The invention according to claim 10 measures the metal concentration of the plating solution after replenishing the metal corresponding to the amount of metal deposited by plating after plating, and the metal concentration of the plating solution immediately before the next plating. The electroless plating apparatus according to claim 8 or 9, wherein the filter is washed when the concentration is lower than the latter metal concentration.

According to the present invention, the amount of the chemical solution containing the plating solution is reduced to the outside, the liquid cost per substrate is reduced, and the cleaning time in the cleaning process is shortened to improve the throughput. be able to. In addition, flushing with an etching solution or the like inside the plating solution circulation line can be performed easily and quickly.
Further, by constantly monitoring and managing the state of the plating solution and the plating apparatus through the metal concentration of the plating solution, it is possible to avoid problems with the plating apparatus in advance and to operate the apparatus without damaging the product.

It is sectional drawing which shows the example of joining of a micro bump. It is sectional drawing which shows the example of a connection of TSV wiring. It is sectional drawing which shows the example which forms Ni plating film and Au plating film on the surface of a bump pad by electroless plating in order of a process. 1 is an overall plan view of an electroless plating apparatus according to an embodiment of the present invention. It is a front view which shows the outline | summary of the board | substrate holder of the board | substrate conveyance apparatus between modules. FIG. 6 is a right side view of FIG. 5. It is a schematic longitudinal front view which shows the zincate processing tank and substrate holder of a zincate processing module. It is a schematic sectional side view which shows the zincate processing tank and substrate holder of a zincate processing module. It is a schematic longitudinal front view which shows the zincate processing tank and substrate holder of a zincate processing module. It is a schematic longitudinal cross-sectional front view which shows the Ni plating tank and board | substrate holder of a Ni plating module. It is a block diagram which shows a series of processes by the electroless-plating apparatus shown in FIG. It is a flowchart attached | subjected to description of management of Ni plating solution used for electroless Ni plating.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following examples, the same or corresponding members are denoted by the same reference numerals, and redundant description is omitted.

  In the following example, as shown in FIG. 3A, a substrate W such as a semiconductor wafer provided with a bump pad 40 made of Al having a diameter D of several μm, for example, is prepared. Then, as shown in FIG. 3B, a zincate treatment as a plating pretreatment is performed on the surface of the substrate W, and a zinc plating film 42 is formed on the surface of the bump pad 40 by displacement plating. An Ni plating film 44 of 1.6 μm, for example, is formed on the surface of the film 42 by electroless plating, and an Au plating film of 0.1 μm, for example, is formed on the surface of the Ni plating film 44 by displacement plating (electroless plating). 46 is formed.

  FIG. 4 is an overall plan view showing an outline of the electroless plating apparatus according to the embodiment of the present invention. As shown in FIG. 4, this electroless plating apparatus has a substantially rectangular housing 50 having an air-conditioning function that uses air as a downflow, and is disposed adjacent to the housing 50 and stocks a large number of substrates such as semiconductor wafers. A load port 52 on which a substrate cassette to be mounted is placed. The load port 52 can be mounted with an open cassette, a SMIF (Standard Manufacturing Interface) pod, or a FOUP (Front Opening Unified Pod).

  Inside the housing 50, in order from the opposite side of the load port 52, a pre-cleaning module 58 having a pre-cleaning tank 54 and a water-washing tank 56, a zincate processing tank (plating pretreatment tank) 60 for performing a zincate process as a plating pretreatment, A zincate processing (plating pretreatment) module 64 having a water rinsing tank 62, an Ni plating module 70 having an Ni plating tank 66 and a water rinsing tank 68, an Au plating module 76 having an Au plating tank 72 and a water rinsing tank 74, and a drying unit 78 They are arranged in series.

  The pre-cleaning module 58 is movable in the vertical and horizontal directions, and is a substrate holder that transports the substrate between the pre-cleaning tank 54 and the water-washing tank 56 and immerses the substrate in the processing liquid in the pre-cleaning tank 54 and the water-washing tank 56. 80a is provided. Similarly, the zincate processing module 64 includes a substrate holder 80b for transporting the substrate between the zincate processing tank 60 and the water washing tank 62, and the Ni plating module 70 includes between the Ni plating tank 66 and the water washing tank 68. A substrate holder 80c for transporting the substrate is provided, and the Au plating module 76 is provided with a substrate holder 80d for transporting the substrate between the Au plating tank 72 and the water washing tank 74, respectively.

  Here, it is preferable that at least one of the zincate treatment tank 60 and the water washing tank 62 of the zincate treatment module 64 and the water washing tanks 68 and 74 of the plating modules 70 and 76 have a QDR (Quick Dump Rinse) function. Thus, the substrate surface can be sufficiently rinsed (washed with water) in a short time, and the apparatus can be made compact and compact.

  Further, in parallel with the substrate holders 80a to 80d and the drying unit 78, a substrate holder 84 that can run along the guide 82 is provided, and a plurality of substrates are conveyed to each of the substrate holders 80a to 80d and the drying unit. An inter-module board transfer device 86 that transfers a plurality of boards to and from the board 78 is disposed.

  As described above, by providing the substrate holders 80a to 80d in the modules 64, 70, and 76 separately from the inter-module substrate transfer device 86, the configuration of the substrate holders 80a to 80d is further simplified, and the plating solution is contained. The amount of the chemical solution taken out can be reduced, and at the same time, the cleaning time in the cleaning step can be shortened to improve the throughput. The substrate holders 80a to 80d include a substrate moving mechanism that moves the substrate up and down or vibrates as necessary during processing in each processing solution.

  In this example, the inter-module substrate transfer device 86 is also used to transfer a plurality of substrates held by the substrate holder 84 to the drying unit 78 for drying.

  Further, the housing is located on the load port 52 side, and a plurality of substrates in the load port 52 are simultaneously loaded into the housing 50 or a plurality of substrates in the housing 50 are unloaded to the load port 52. An incoming substrate transfer device 90 is movably disposed, and a temporary placement station 92 for temporarily placing a plurality of substrates is disposed between the carry-in / out substrate transport device 90 and the drying module 78.

Thus, the carry-in / out substrate transfer device 90 simultaneously receives and transfers, for example, 25 substrates stocked in the load port 52, temporarily places them in the temporary placement station 92 in the vertical direction, and repeats this twice. by that return, the temporary station 92, for example, temporarily placed 50 substrates in the vertical direction. The inter-module substrate transfer device 86 simultaneously receives, for example, 50 substrates temporarily placed in the temporary placement station 92 in the vertical direction, and transports them to, for example, the pre-cleaning module 58 and transfers them to the substrate holder 80a of the pre-cleaning module 58. Hand over at the same time. The processed substrate is temporarily placed in the temporary placement station 92 by the reverse operation to the above, and then returned to the load port 52 by the carry-in / out substrate transfer device 90.

  In this example, the pre-cleaning tank 54 removes the oxide film on the surface of the substrate W, and further, the surface of the zinc plating film formed by substitution plating on the surface of the bump pad 40 (see FIG. 3) during the double zincate process. Nitric acid is used as a pre-cleaning solution to remove water. A pre-cleaning liquid (nitric acid) storage tank 100 for storing the pre-cleaning liquid (nitric acid) is disposed outside the housing 50, and a pre-cleaning liquid supply line 102 extending from the pre-cleaning liquid storage tank 100 is connected to the pre-cleaning tank 54.

  A zincate solution storage tank 104 for storing a zincate solution made of, for example, a sodium hydroxide-based zinc oxide-containing solution is disposed outside the housing 50, and a zincate solution supply line 106 extending from the zincate solution storage tank 104 is connected to the zincate treatment tank 60. Has been.

  An Ni plating solution storage tank 108 for storing a Ni plating solution and a flushing solution storage tank 110 made of nitric acid in this example and used for flushing with the following etching solution are stored outside the housing 50. The Ni plating solution supply line 112 extending from the plating solution storage tank 108 and the flushing line 114 extending from the flushing solution storage tank 110 are connected to the Ni plating tank 66.

  Outside the housing 50, there are an Au plating solution storage tank 116 for storing an Au plating solution, and a flushing solution storage tank 118 for storing a flushing solution used for flushing with the following etching solution, which is a mixed solution of nitric acid and hydrochloric acid in this example. The Au plating solution supply line 120 disposed and extending from the Au plating solution storage tank 116 and the flushing line 122 extending from the flushing solution storage tank 118 are connected to the Au plating tank 72.

  The Ni plating solution reservoir 108 is provided with a plating solution analyzer 124 that analyzes the Ni plating solution and measures the metal (Ni) ion concentration, pH, and the like of the Ni plating solution. Similarly, the Au plating solution storage tank 116 is provided with a plating solution analyzer 126 that analyzes the Au plating solution and measures the metal (Au) ion concentration, pH, and the like.

  FIG. 5 is a front view showing an outline of the substrate holder 84 of the inter-module substrate transfer apparatus 86, and FIG. 6 is a right side view of FIG. As shown in FIGS. 5 and 6, the substrate holder 84 includes a base 130 and a plurality of pairs of transfer arms 132 that can be opened and closed. Then, with the transfer arm 132 open, the transfer arm 132 is lowered from above the plurality of substrates W arranged in parallel in the vertical direction, and the transfer arm 132 is closed, whereby a plurality of (for example, 50) substrates are provided. W is simultaneously gripped from above and the holding of the substrate W is released by the reverse operation. The inter-module substrate transfer device 86 is configured to clean the transfer arm 132 at an appropriate time in order to prevent contamination in each tank.

  FIG. 7 is a schematic longitudinal front view showing the zincate processing tank 60 and the substrate holder 80b of the zincate processing module 64, and FIG. 8 is a schematic side sectional view of the same. As shown in FIGS. 7 and 8, the zincate treatment tank 60 has an inner tank 140 and an outer tank 142, and an overflow tank 144 is formed between the inner tank 140 and the outer tank 142. One end of a zincate (plating pretreatment liquid) circulation line 152 including a pump 146, a temperature controller 148 and a filter 150 is connected to the bottom of the overflow tank 144 of the zincate treatment tank 60. Is connected to the bottom of the inner tub 140. Further, a rectifying plate 154 that arranges the flow of the processing liquid is disposed at the bottom of the inner tank 140.

  Accordingly, the zincate liquid in the zincate treatment tank 60 is filtered by the filter 150 as the pump 146 is driven, and overflows the inside of the inner tank 140 while the temperature is adjusted to, for example, 50 ° C. by the temperature regulator 148. It circulates between the tanks 144. The upstream side of the pump 146 in the zincate circulation line 152 and the downstream side of the filter 150 are connected by a short-circuit line 156, and a zincate supply line 106 extending from the zincate liquid storage tank 104 is connected to the zincate circulation line 152. It is connected.

  The pre-cleaning tank 54 has the same configuration as the zincate processing tank 60. However, in the pre-cleaning tank 54, the temperature of the treatment liquid (nitric acid) generally does not need to be adjusted (used at room temperature), and therefore the temperature regulator 108 may be omitted.

  As shown in FIGS. 7 and 8, the substrate holder 80 b extends between the pair of side plates 164 disposed opposite to each other at a predetermined interval and supports the outer peripheral portion of the substrate W from below. A plurality of support bars 166 are provided.

Thereby, the substrate holder 80b supports a plurality of (for example, 50) substrates W by the support rod 166 below the substrate W, and thereby the substrate of the inter-module substrate transfer device 86 that holds the substrate W from above. The substrate can be smoothly transferred to and from the holder 84. The other substrate holders 80a, 80c, and 80d have the same configuration as the substrate holder 80b.

  FIG. 9 is a schematic longitudinal sectional front view showing the rinsing tank 62 and the substrate holder 80b of the zincate processing module 64. FIG. The rinsing tank 62 uses pure water as the treatment liquid. The washing tank 62 has an inner tank 170 and an outer tank 172, and an overflow tank 174 is formed between the inner tank 170 and the outer tank 172. A pure water supply line 176 is connected to the bottom of the inner tank 170, and a drainage line 178 is connected to the bottom of the overflow tank 174. As a result, the pure water supplied to the inner tank 170 through the pure water supply line 176 fills the inside of the inner tank 170, and then overflows into the overflow tank 174 so as to be drained from the drain line 178. It has become.

  The other rinsing tanks 56, 68, 74 also have the same configuration as the rinsing tank 62. However, in the rinsing tanks 68 and 74 of the plating modules 70 and 78, as shown by phantom lines in FIG. 9, a chemical solution supply that supplies a chemical solution for removing the oxide film on the plating film surface to the bottom of the inner tank 170. The line 180 may be connected.

  FIG. 10 is a schematic longitudinal sectional front view showing the Ni plating tank 66 and the substrate holder 80c of the Ni plating module 70, and FIG. 11 is also a schematic sectional side view. Since the substrate holder 80c has the same configuration as the substrate holder 80b as described above, the same members are denoted by the same reference numerals, and redundant description is omitted.

As shown in FIG. 10, the Ni plating tank 66 has an inner tank 190 and an outer tank 192, and an overflow tank 194 is formed between the inner tank 190 and the outer tank 192. One end of a plating solution circulation line 202 having a pump 196, a temperature controller 198 and a filter 200 interposed therebetween is connected to the Ni plating tank 66, and the other end of the plating solution circulation line 202 is connected to the bottom of the inner tank 190. Has been. Further, a rectifying plate 204 that arranges the flow of the Ni plating solution is disposed at the bottom of the inner tank 190.

  As a result, the plating solution in the Ni plating tank 66 is filtered by the filter 200 as the pump 196 is driven, and overflows the inside of the inner tank 190 while the temperature is adjusted to, for example, 80 ° C. by the temperature regulator 198. It circulates between the tanks 194. The upstream side of the pump 196 in the plating solution circulation line 202 and the downstream side of the filter 200 are connected by a short-circuit line 206.

  Further, a Ni plating solution supply line 112 extending from the Ni plating solution storage tank 108 and a flushing line 114 extending from the flushing solution storage tank 110 are connected to the plating solution circulation line 152. Thus, after removing the Ni plating solution in the Ni plating tank 66 and the plating solution circulation line 202, a flushing solution (etching solution) such as nitric acid is passed from the plating solution circulation line 202 to the Ni plating solution storage tank 108 through the flushing line 114. The inside of the plating solution circulation line 202 and the Ni plating solution storage tank 108 can be flushed with the flushing solution (etching solution) by introducing the flushing solution into the inside and circulating it through the pump 196.

  The overflow tank 194 includes a plating solution analyzer 210 that analyzes the Ni plating solution in the overflow vessel 194 and measures the metal (Ni) ion concentration, pH, and the like of the Ni plating solution, and the analysis of the plating solution analyzer 210. Based on the results, a plating solution replenishing device 212 for replenishing the Ni plating solution in the overflow tank 194 with a replenisher having a predetermined metal concentration is provided.

  Note that the Au plating tank 72 has substantially the same configuration as the Ni plating tank 66. However, in the Au plating tank 72, the temperature of the Au plating solution is adjusted to 75 ° C., for example.

  Next, a series of processes by the electroless plating apparatus shown in FIG. 4 will be described with further reference to FIG.

  First, as described above, a plurality of (for example, 50) substrates temporarily placed on the temporary placement station 92 are gripped from above by the substrate holding unit 84 of the inter-module substrate transfer device 86 and transferred to the pre-cleaning module 58. . The substrate holder 80a of the pre-cleaning module 58 simultaneously receives a plurality of substrates W from the substrate holding unit 84 of the inter-module substrate transfer device 86 and holds them in the vertical direction. At this time, the substrate holder 80a is located immediately above the pre-cleaning tank 54.

  Then, the substrate holder 80a is lowered, and the plurality of substrates W held by the substrate holder 80a are immersed in the treatment liquid (nitric acid) in the pre-cleaning tank 54, for example, for 1 minute. The oxide film is removed.

  Next, the plurality of substrates W held by the substrate holder 80 a are pulled up from the treatment liquid (nitric acid) in the pre-cleaning tank 54 and moved directly above the washing tank 56. Then, the substrate holder 80a is lowered, and the plurality of substrates W held by the substrate holder 80a are immersed in the processing liquid (pure water) in the water rinsing tank 56 for 5 minutes, for example. Wash with water. Thereafter, the plurality of substrates W held by the substrate holder 80a are pulled up from the processing liquid (pure water) in the washing tank 52.

  Next, the plurality of substrates W held in the vertical direction by the substrate holder 80 a are delivered to the substrate holder 80 b of the zincate processing module 64 via the substrate holder 84 of the inter-module substrate transfer device 86. The substrate holder 80b is located immediately above the zincate treatment tank 60.

  Next, the substrate holder 80b is lowered, and a plurality of substrates W held by the substrate holder 80b are immersed in a treatment liquid (zincate liquid) in the zincate treatment tank 60, for example, for 30 seconds, thereby comprising Al. A first zincate process is performed on the surface of the bump pad 40 (see FIG. 3). Then, the plurality of substrates W held by the substrate holder 80 b are pulled up from the processing liquid (zincate liquid) in the zincate processing tank 56.

  Next, almost in the same manner as described above, the plurality of substrates W held by the substrate holder 80 b are moved directly above the washing tank 62. Then, the substrate holder 80b is lowered, and the plurality of substrates W held by the substrate holder 80b are immersed in the processing liquid (pure water) in the water washing tank 62, for example, for 1 minute. Wash with water. Thereafter, the plurality of substrates W held by the substrate holder 80b are pulled up from the processing liquid (pure water) in the washing tank 62.

  This cycle is repeated twice, with the substrate immersed in nitric acid and then washed with water, and immersed in the zincate solution and then washed with water, whereby a so-called double zincate treatment is performed. In this way, by performing the double zincate process, the zinc (zinc plating film) roughly applied to the surface of the bump pad 40 made of Al (see FIG. 3) by the first zincate process is removed with nitric acid. Thereafter, the surface of the bump pad 40 can be finely replaced with zinc by the second zincate treatment. Thereby, the galvanized film 42 shown in FIG. 3B is formed.

  Next, the substrate after the double zincate treatment is transferred to the substrate holder 80 c of the Ni plating module 70 via the substrate holder 84 of the inter-module substrate transfer device 86. Then, in substantially the same manner as the above-described zincate treatment, a plurality of substrates held in the vertical direction by the substrate holder 80c are immersed in, for example, a Ni plating solution having a liquid temperature of 80 ° C. in the Ni plating tank 66 for 50 minutes, for example. Thus, the Ni plating film 44 shown in FIG. 3B is formed. Thereafter, the substrate after Ni plating is immersed in a treatment liquid (pure water) in the water rinsing tank 68 for 5 minutes, for example, and washed with water.

  Next, the substrate after Ni plating is transferred to the substrate holder 80 d of the Au plating module 76 via the substrate holder 84 of the inter-module substrate transfer device 86. Then, in substantially the same manner as the above-described zincate treatment, a plurality of substrates held in the vertical direction by the substrate holder 80d are immersed in, for example, an Au plating solution having a liquid temperature of 75 ° C. for 10 minutes in the Au plating tank 72, for example. Thus, an Au plating film 46 shown in FIG. 3B is formed. Thereafter, the substrate after Au plating is immersed in a treatment liquid (pure water) in a water rinsing tank 74 for 5 minutes, for example, and washed with water.

  Next, the substrate after Au plating is held by the substrate holder 84 of the inter-module substrate transfer device 86 and transferred to the drying unit 78, where the drying unit 78 is dried using air blow or IPA (isopropyl alcohol) vapor, for example. Dry by method.

  Then, the substrate holder 84 of the inter-module substrate transport apparatus 86 transports the dried substrate W to the temporary placement station 92 and temporarily places it, and returns the temporarily placed substrate to the load port 52. This completes a series of electroless plating processes.

  As described above, when electroless Ni plating is performed using the batch processing method, deposits such as Ni adhere to the inside of the Ni plating tank 66 and the plating solution circulation line 202. For this reason, for example, after processing 100 substrates, it is necessary to flush the deposits adhering to the inside of the Ni plating tank 66 and the plating solution circulation line 202 with an etching solution or the like.

  Therefore, in this example, when it is necessary to perform flushing in this way, the Ni plating solution is removed from the Ni plating bath 66 and the plating solution circulation line 202, and the Ni plating vessel 66 and the plating solution circulation are passed through the flushing line 114. For example, a flushing solution such as nitric acid used for Ni etching is introduced into the line 202 and circulated to perform flushing with the etching solution in the Ni plating tank 66 and the plating solution circulation line 202. As a result, flushing with an etching solution or the like in the Ni plating tank 66 and the plating solution circulation line 202 can be performed easily and quickly.

  This also applies to the Au plating tank 72. In the case of the Au plating tank 72, for example, a mixed liquid of nitric acid and hydrochloric acid used for Au etching is used as the flushing liquid.

  Next, management of a Ni plating solution used for electroless Ni plating will be described with reference to a flowchart shown in FIG.

  First, plating conditions such as the pattern aperture ratio of the substrate and the plating time are set. Thereby, the metal deposition amount by plating is calculated | required as the target metal deposition amount F (plating conditions) from the film-forming rate calculated | required previously. Next, the metal concentration A during the bathing of the plating solution is measured (step 2), and it is confirmed whether or not the metal concentration A during the bathing is within a specified value (step 3). If the metal concentration A at the time of bathing the plating solution is not within the specified value, the plating solution is replenished with metal (step 4) and the process returns to step 3 again. When the metal supply of the plating solution (step 3) is repeated twice, it is determined that the apparatus is abnormal (step 5), for example, an alarm is sounded.

  When it is confirmed that the metal concentration A during the bathing of the plating solution is within the specified value, the metal concentration B immediately before plating of the plating solution is measured (step 6). Step 6 may be skipped when the bathing and plating are performed continuously. Then, actual plating is performed (step 7), and the metal concentration C immediately after plating with the plating solution is measured (step 8).

  Next, from the concentration difference between the metal concentration B immediately before plating of the plating solution and the metal concentration C immediately after plating and the known plating solution amount, the actual metal precipitation amount F (B, C) actually deposited at the time of plating is calculated, Comparison with the target metal deposition amount F (plating conditions) is performed (step 9). This comparison corrects the degree of aging of the plating solution and the decrease in plating rate accompanying aging.

  That is, when the actual metal deposition amount F (B, C) is smaller than the target metal deposition amount value F (plating condition) (F (B, C) <F (plating condition)), the metal concentration of the replenisher to be replenished Is corrected to a value previously obtained by actual measurement or the like (step 10). On the other hand, when the actual metal deposition amount F (B, C) is equal to or greater than the target metal deposition amount value F (plating condition) ((F (B, C) ≧ F (plating condition)), the replenisher to be replenished According to the amount of deposited metal, the replenisher is supplied to the plating solution through the plating solution replenishing device 206 (see FIG. 10) (step 11). The metal concentration D immediately after replenishment is measured (step 12) By operating in this way, the life of the plating solution can be extended while minimizing fluctuations in the plating rate.

  When the plating is performed again, the metal concentration B immediately before plating of the plating solution is measured again. Then, the difference between the metal concentration D immediately after the replenishment of the plating solution and the metal concentration B immediately before the plating is obtained to determine whether or not the plating solution concentration has decreased over time. That is, when the difference between the metal concentration D immediately after replenishing the plating solution and the metal concentration B immediately before plating is positive (D−B> 0), plating is performed in the plating apparatus (Ni plating tank 66 and plating solution circulation line 202). The filter 200 (see FIG. 10) is washed with an etching solution or the like, and the process returns to Step 11.

  When the difference between the metal concentration D immediately after replenishment of the replenisher and the metal concentration B immediately before the plating solution is negative (D−B ≦ 0), the number of corrections n for correcting the metal concentration of the replenisher is a predetermined value. It is determined whether or not the number of corrections nr has been reached (step 15). If the predetermined number of corrections has not been reached (n ≦ nr), the process returns to step 7 where the predetermined number of corrections has been reached (n> In nr), a reconstruction bath is performed (step 17), and the process returns to the start.

  In this way, the plating amount (convertible to plating film thickness) is obtained from the metal concentration of the plating solution before and after plating, and a replenisher with a predetermined metal concentration is replenished to the plating solution according to the difference from the assumed plating amount. To do. At this time, by replenishing the plating solution with the replenisher, the metal concentration of the plating solution before plating may return to the initial concentration, or may be higher than the initial concentration. As a result, it is possible to prevent the plating rate from being reduced due to factors other than the metal concentration of the plating solution, and as a whole, the fluctuation range of the plating film thickness can be further reduced to cope with an unexpected reduction in the plating rate.

  Although one embodiment of the present invention has been described so far, it is needless to say that the present invention is not limited to the above-described embodiment, and may be implemented in various forms within the scope of the technical idea.

40 Bump pad 42 Zinc plating film 44 Ni plating film 46 Au plating film 54 Pre-cleaning tank 56, 62, 68, 74 Water-washing tank 58 Pre-cleaning module 60 Jincate treatment (pre-plating treatment) tank 64 66 Ni plating tank 70 Ni plating module 72 Au plating tank 76 Au plating module 78 Drying unit 80a, 80b, 80c, 80d Substrate holder 84 Substrate catcher 86 Inter-module substrate transfer device 92 Temporary placement station 100 Pretreatment liquid (nitric acid) Storage tank 102 Pretreatment liquid supply line 104 Jincate liquid storage tank 106 Jincate liquid supply line 108 Ni plating liquid storage tank 110, 118 Flushing liquid storage tank 112 Ni plating liquid supply line 114, 122 Flushing line 116 Au plating liquid storage tank 120 A u plating solution supply line 124, 126, 210 plating solution analyzer 132 transfer arm 148, 198 temperature regulator 150, 200 filter 152 zincate solution circulation line 164 side plate 166 support rod 202 plating solution circulation line 206 replenisher solution supply device

Claims (10)

A pre-plating treatment tank having a pre-plating treatment tank for performing pre-plating treatment, a water washing tank for washing the substrate after the pre-plating treatment, and a substrate holder for supporting and transporting a plurality of substrates below the substrate between them; ,
Plating tank having electroless plating on the substrate surface after pre-plating treatment, water rinsing tank for washing the substrate after electroless plating, and a substrate holder for supporting and transporting a plurality of substrates below between them Modules,
An inter-module substrate transfer device that holds and transfers a plurality of substrates from above between the plating pretreatment module and the plating module;
The plating pretreatment tank has a plating pretreatment liquid circulation line having a temperature adjustment function of the plating pretreatment liquid,
The plating tank has a plating solution circulation line having a temperature control function of a filter and a plating solution,
The electroless plating apparatus, wherein the plating solution circulation line is connected to the plating solution circulation line and a flushing line for flushing the inside of the plating tank.   2. The electroless plating apparatus according to claim 1, wherein the plating pretreatment is a zincate treatment on an Al surface, and the plating pretreatment bath is a zincate treatment bath.   The electroless plating apparatus according to claim 1 or 2, wherein the washing tank of the plating module has a chemical supply line for supplying a chemical for removing an oxide film on the surface of the plating film.   4. The at least one tank of the plating pretreatment tank and the water washing tank of the plating pretreatment module and the water washing tank of the plating module has a QDR function. 5. The electroless plating apparatus described in 1. The plating pretreatment module and the plating module, electroless plating apparatus according to any one of claims 1 to 4, characterized in that it is accommodated in a housing having an air conditioning function of the air and the downflow . Electroless plating apparatus according to any one of claims 1 to 5, characterized in that it comprises a drying unit for drying the substrate was washed with water after the plating.   The electroless plating apparatus according to any one of claims 1 to 6, further comprising a temporary placement station for temporarily placing a plurality of substrates before processing.   The plating tank measures the metal concentration of the plating solution immediately before plating and the metal concentration of the plating solution immediately after plating, calculates the amount of deposited metal from the difference between these metal concentrations, and compares the amount of deposited metal with a target value. And a plating solution replenishing device that replenishes the plating solution corrected to a predetermined metal concentration in accordance with the amount of deposited metal. Electroplating equipment.   9. The electroless plating apparatus according to claim 8, wherein the reconstruction bath is performed when the number of corrections for correcting the metal concentration of the replenishing plating solution exceeds a preset number of corrections.   Measure the metal concentration of the plating solution after replenishing the metal corresponding to the amount of metal deposited after plating, and the metal concentration of the plating solution immediately before the next plating, and the former metal concentration is more than the latter metal concentration The electroless plating apparatus according to claim 8 or 9, wherein the filter is washed when the value is lower.

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