JP4627862B2 - Plating equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plating apparatus for plating a processed product, and more specifically to a plating apparatus for performing a plating process on a semiconductor device such as a lead frame on which a semiconductor chip is mounted and resin-sealed.
[0002]
[Prior art]
When a plating process is performed on a processed product such as a lead frame assembly on which a semiconductor chip is mounted and resin-sealed, there is a problem of how to control the plating film thickness to a desired thickness. In the plating process on the lead frame assembly, if the plating film thickness does not fall within a predetermined range, there is a possibility that the lead frame assembly cannot be inserted into the outlet hole or is too loose to fall off. In order to avoid such occurrence of the plating film thickness outside the target range, a method has been proposed in which the plating area of the treated product is determined to control the total amount of current flowing in the plating bath, and to adjust the plating time (specialty). (Kaihei 4-74897, JP-A-3-148162). According to these methods, since the current and the plating time are adjusted in accordance with the plating area, the plating film thickness within the target range can be obtained relatively stably.
[0003]
[Problems to be solved by the invention]
However, in the above method, although a plurality of power supply stages are continuously provided in the plating bath, since only one power source is provided for the plating bath, it is not possible to set a fine current for each power supply stage. For this reason, if there is an input part where there is no processed product in the middle, the plating current flows as if there is an average number of processed products. The thickness was excessive and could not be within the target range. For this reason, it has been practiced to insert a dummy group in a predetermined range before and after the input portion where there is no processed product to prevent deviation of the plating film thickness. However, it is desirable to avoid the introduction of such dummy groups because unnecessary plating is performed.
[0004]
For this reason, a plating apparatus in which the plating apparatus is divided into a plurality of stages with respect to the traveling direction and a power source is provided for each stage has been proposed (Japanese Patent Publication No. 7-74479). According to this plating apparatus, an electric current can be allowed to flow in accordance with the type of processed product and the plating area for each stage of the plating apparatus, and the plating film thickness can be accurately controlled. Further, even when there is no processed product in one group, it is possible to avoid a situation in which the thickness of the processed product positioned before and after the dummy processed product is not excessively increased.
[0005]
However, in the above-described tact feed type plating apparatus, it is detected by the timer or the transport tact time of the transport apparatus that the processed product has arrived at the energization section of the plating apparatus. For this reason, when an unexpected situation such as the stoppage of the apparatus occurs, there is a problem that it is difficult to grasp the position of the processed product, the current application timing is shifted, or the current cannot be applied. In addition, in the pre-plating treatment process, the processed product may fall out of the transfer device. In such a case, there is a problem that the plating current set as no dropout becomes excessive and the plating film thickness becomes too thick. For this reason, it has been required to develop a plating apparatus for setting a plating current after reliably grasping the number of processed products that have reached the energization section of the plating apparatus.
[0006]
The present invention provides a plating apparatus capable of flowing an appropriate current for forming a predetermined plating film thickness without causing a shift in the timing of current application after reliably grasping the number of processed products arriving at the plating apparatus. The purpose is to do.
[0007]
[Means for Solving the Problems]
The plating apparatus of the present invention includes a transfer device divided into unit sections along a traveling direction, and a processing apparatus divided into processing stages having a length corresponding to one or more unit sections of the transfer device. However, this is a tact feed type plating apparatus that holds a processed product in a processed product holder arranged in a unit section and intermittently feeds through the processing apparatus sequentially. The plating apparatus includes a power source for supplying a current for processing provided in each processing stage, a processing product number detection unit that is disposed on the inlet side of the plating device and detects the number of processing products sent to the plating device, Corresponding to the input order of processed products, a series number specifying means for specifying the series number assigned to the processed products for each unit classification, information about the processing stage input in advance, and the types of processed products and their types Based on the storage means for storing information on the plating area, the number of detected processed products, the type of processed product to which the processed product of the specified series number belongs, the plating area of that type, and information on the processing stage. Calculating the plating area in the processing stage, calculating the plating current in the processing stage, and automatically setting the calculated current to To shed its current, and a current automatic setting means (claim 1).
[0008]
The processing apparatus of the plating apparatus of the present invention is divided into an integral multiple of one unit division as one processing stage. That is, the processing stages are 1 unit division, 2 unit division, 3 unit division,... For example, when four processed product holders are arranged in parallel in each unit section, if the processed products are held in all the processed product holders in each unit section, four processing product holders are used in the processing stage of one unit section. Processed products will be processed. In addition, 8 processed products are processed in the processing stage of the 2 unit section, and 12 processed products are processed in the processing stage of the 3 unit section. The number of processed product holders arranged in the unit section is not limited to a plurality and may be one.
[0009]
In the above, the “information regarding the processing stage” is information indicating how many unit sections have the length and how many tact feed positions the processing stage is from the entrance of the plating apparatus. Note that “tact feed” refers to an operation in which the conveying device moves the processed product intermittently. Usually, the distance transported by this one tact feed corresponds to the length of one unit section. In some cases, the length in the traveling direction of one unit section may be represented by.
[0010]
With the above configuration, it is possible to detect the number of processed products constituting one unit section at the entrance of the plating apparatus, and further the number of processed products constituting the processing stage. For this reason, even when the conveying device is suddenly stopped and restarted, a current can be supplied to the plating apparatus at an appropriate timing. In addition, since the plating area can be calculated based on the exact number of processed products entering the plating apparatus, an appropriate plating current can be set. In addition, an appropriate current should be applied to a processed product consisting of the number of processed products that cannot hold all processed product holders in one unit division, such as the lot end of a lot that generates fractions. Can do. Further, even when an accident such as partial removal of a processed product occurs, a plating film thickness in a desired range can be obtained. As a matter of course, when all of the processed products fall off, a plating current of zero is calculated and no plating current is passed.
[0011]
In the following description, the “plating apparatus” may be considered as the entire plating apparatus, or may be considered as a plating bath apparatus, a pre-plating processing apparatus, or a post-plating processing apparatus that is a part of the plating apparatus. Furthermore, in a device having a processing length of 100 tact feed number or more, such as a plating pretreatment device, a specific partial pretreatment device may be used. Here, in the case of, for example, a resin-sealed lead frame, the processed product held by the processed product holder is not a single lead frame but a large number of lead frame assemblies provided in the frame.
[0012]
Moreover, in the plating apparatus of the said invention, you may be divided and comprised by the some process stage corresponding to the same unit division length. For example, when the plating bath corresponds to the above-described plating apparatus, it is often divided into processing stages corresponding to the same number of unit sections from the entrance to the exit of the plating bath.
[0013]
In the plating apparatus of the present invention, for example, a plurality of processed product holders may be arranged in parallel in the unit section, and each processed product holder can hold one processed product. ).
[0014]
By holding one processed product per one processed product holder as described above, the plating process can be accurately performed for each processed product. Further, as described above, for example, the processing can be efficiently performed by arranging four processed product holders in parallel in one unit section.
[0015]
In the plating apparatus of the present invention, for example, one processed product holder may be arranged in the unit section, and each processed product holder can hold one processed product (claim). 3).
[0016]
By the said structure, it can process by the arrangement | positioning of the same electrode with respect to all the processed goods. That is, as in the case of parallel arrangement of a plurality of columns, there is no difference between the positions of the end columns and the positions of the columns sandwiched between the columns.
[0017]
In the plating apparatus of the present invention, the number of processed product detection means is, for example, whether or not the processed product holders arranged are arranged for each row along the traveling direction, and whether or not the processed products are held in the processed product holders in that row. (Claim 4).
[0018]
With this configuration, the number of processed products in each unit section can be detected by providing one processed product detecting means near the entrance for each processed product holder row. In addition, since it is only necessary to detect whether or not the processed product is held in the processed product holder, the number of processed products is detected using a simple optical device such as a non-contact sensor, a contact sensor, or a CCD (Charge Coupling Device) camera. Can be configured.
[0019]
In the plating apparatus of the present invention, the series number specifying means can be, for example, a counter that counts the number of tact feeds from the reference time of operation of the plating apparatus.
[0020]
Step-driven plating apparatuses generally have a pretreatment process of 150 to 200 treatment stages before the plating bath. When targeting a plating bath, or when targeting a predetermined process in the pretreatment process, the tact is started from the stage when the beginning of a lot consisting of the same type of processed product passes through a predetermined reference processing stage of this plating apparatus. By counting the number of feeds, the series number of the processing group detected by the processed product detection means can be specified. Then, the lot to which the processed product of the series number belongs is known, and therefore the type of processed product of the series number is determined.
[0021]
The plating apparatus of the present invention includes timer means for starting to supply current to the power supply after a predetermined number of tact feeds have elapsed since the number of processed articles is detected by the processed article number detecting means.
[0022]
As in the plating pretreatment step, there is a step of 100 to 200 tact feeding, and there are cases where it is provided in front of the pretreatment step for the processed product number detection means considerably away from the situation such as the layout of the apparatus. In such a case, it is desirable to flow the calculated plating current to each stage of the target process after a predetermined tact feed number has elapsed. As a result, the effect of the present plating apparatus can be exhibited flexibly without being restricted by the layout of the apparatus.
[0023]
The plating apparatus of the present invention further includes a lot end detection means for detecting the end of the lot of the processed product, and the current automatic setting means is based on a lot end detection signal from the lot end detection means and has a predetermined weak current. Is caused to flow to the power source (claim 7).
[0024]
The lot end detecting means detects the lot end based on the data of the processed product number detecting means, the series number specifying means and the like. The lot end detection means may be configured by only the processed product number detection means. The automatic current setting means can prevent substitution of noble metals such as gold, silver, and copper to the anode or cathode of the plating apparatus by passing a weak current through each stage of the plating bath after passing the lot end. . As a result, the durability of the plating apparatus can be increased, the continuous operation time of the plating apparatus can be lengthened, and the plating efficiency of the processed product can be improved. This weak current can be arbitrarily set in a storage device such as a personal computer.
[0025]
The plating apparatus of the present invention further includes a completed processing product number detecting means for detecting the number of processed products sent out from the plating device at the outlet of the plating device.
[0026]
With the above configuration, it is possible to manage not only the number of processed products that have been put into the process, but also the number of payouts that have been processed, making it easy to extract the processed products remaining in the plating equipment and manage the processed products Can be done.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0028]
(Embodiment 1)
FIG. 1 is a plan view showing an outline of the layout of the plating apparatus according to Embodiment 1 of the present invention. The processed product to be processed is a lead frame (hereinafter referred to as a frame) sealed with resin. Lots composed of the same type of frame are loaded from the inloader 2 and are intermittently and sequentially tucked to the left by a transfer device (not shown). The tact feed interval is, for example, 13 seconds. The frame (not shown) is subjected to a ground treatment in the pretreatment unit 3 and sent to the plating treatment unit 10. A monitoring camera 11 composed of a CCD camera is arranged on the entrance side of the plating processing unit 10 to detect the number of frames. In the drawing shown in FIG. 1, the configuration in which the present invention is applied to the plating processing unit 10 is shown, but it may be applied to the preprocessing unit 3 or the postprocessing unit 4. The plating processing unit is divided into processing stages 13, and a power supply 12 is arranged in each processing stage. The frame subjected to the plating process in the plating processing unit 10 is sent to the post-processing unit 4, subjected to the cleaning process, and then sent out from the plating apparatus 1 by the outloader 5.
[0029]
FIG. 2 is a diagram illustrating a relationship among the transfer device, the processing device, and the processed product. The processing device is divided into unit sections 25 with respect to the traveling direction, and four frame holders 21 are arranged in each unit section 25. These frame holders 21 hold one or zero frames 15. Needless to say, the number of frame holders arranged in parallel in each unit section is not limited to four, and may be five or eight, for example.
[0030]
In FIG. 2, the processing apparatus is shown on the right side of the transport apparatus for convenience, but it is needless to say that the processing apparatus and the transport apparatus are actually overlapped. The processing apparatus is divided into processing stages 13, and each processing stage has a length corresponding to one unit section, two unit sections, three unit sections,. A power supply 12 is disposed at each processing stage.
[0031]
Referring to FIG. 2, the end of lot A corresponds to the 98th series number in the lot. The frame group of series number 98 in the lot at the end of the lot is composed of two frames. According to the above arrangement, by using the monitoring camera 11, a highly reliable number of frames can be obtained. The processing stage l that processes this lot end processes frames for two unit sections. Therefore, a total of 6 plating currents of 4 frames of series number 97 and 2 frames of 98 must be passed. Further, in the stage where only one tact is sent from the stage shown in FIG. 2, the current of two frames must be supplied in the processing stage l. After this, when another tact is sent, there is no frame in the processing stage l, so that a weak current flows.
[0032]
The series numbers shown in FIG. 2 are used as follows. When the lot is put into the inloader, the number of processed products of the lot, and thus the total series number, is manually input to the storage unit. Since the number of tact feeds from the inloader to the frame monitoring camera 11 is known, the type (package name) of the product monitored by the frame monitoring camera can be known by counting with the tact feed counter. That is, it is possible to know the lot to which the processed product to be processed by the processing frame belongs and to know the plating area of the processing frame.
[0033]
FIG. 3 is a block diagram when the plating apparatus of the present invention is applied to a plating bath.
When a lot is input to the inloader 2, the number of frames of the same type constituting the lot is input to the storage unit 34 such as a personal computer from the manual input unit 35 such as a keyboard. A database covering all packages has already been stored in advance for the area and the like of the frame of the same type (package name).
[0034]
The frame proceeds from the inloader 2 to the pre-processing unit 3, reaches the entrance of the plating bath (plating processing unit) 10, and the number of frames held in one unit section is detected by the processing product number detection unit 11 such as a frame monitoring camera. The As shown in FIG. 2, it is desirable to install one frame monitoring camera 11 in each row of frame holders. By this time, the number of tact feeds from when the lot is introduced until reaching the plating bath inlet is counted. Therefore, the type (package name) of the processed product can be determined from the storage unit 34. The calculation unit 32 calculates the current that the power supply (rectifier) 12 of the processing stage 13 should flow from the data in the storage unit 34 and the data from the frame monitoring camera 11, sends it to the current automatic setting unit 33, and sends it to the power supply 12. An electric current can be passed. For example, when the lot end of the lot A shown in FIG. 2 is sent from the processing stage 1 to the processing stage m or the processing stage n, the number of frames staying in each processing stage is calculated and an appropriate value of current is passed. be able to. These current settings can be performed in cooperation with the arithmetic unit 32, the tact feed counter 31, and a timer mechanism (not shown).
[0035]
In FIG. 4, the current density to be passed in each processing stage is stored for each package name in the database in the storage unit. In this database, the current density in all the processing stages is entered for each package name so that the present invention can be applied not only to the plating bath but also to the pretreatment unit and the posttreatment unit. In this database, the number of unit sections corresponding to each processing stage is written together. The number of frames corresponding to the unit section is calculated based on data from the frame monitoring camera, etc., and the current in the appropriate processing frame is calculated. Can be calculated.
[0036]
With the above configuration, even if a situation such as a conveyance stop occurs, the number of frames in each unit section can be accurately grasped, and current can be supplied to each processing stage at an accurate timing. Further, since the current value is also calculated based on the number of frames that actually exist, it is possible to accurately enter the desired film thickness range without variations in the plating film thickness. For this reason, it becomes possible to improve the reliability of the product which applied the plating process. In addition, by passing a weak current after detecting the lot end, the electrode of the rectifier is not replaced by a noble metal, so that the durability of the electrode is increased and it can be operated continuously for a long period of time. It can contribute to the improvement of sex.
[0037]
(Embodiment 2)
FIG. 5 is a diagram for explaining the outline of the operation of the plating apparatus according to Embodiment 2 of the present invention. In the present embodiment, a frame monitoring camera 11 is attached to each entrance of the preprocessing unit 2, the plating processing unit (plating bath) 10, and the post-processing unit 4, and according to a signal from each frame monitoring camera, The current value to be passed to the processing stage of each processing unit is calculated by the procedure shown in the first embodiment, the current value is transmitted to the sequencer 33, and the current value is transmitted from the sequencer 33 to the rectifier 12 of each processing stage. Can be directed.
[0038]
In a portion having a large number of processing stages, such as the pre-processing unit 3, it is desirable to use a timer mechanism (not shown) to flow a current for processing the first frame of the lot.
[0039]
With the above configuration, the present invention can be applied to the entire plating apparatus, a current of an appropriate value can be passed at an appropriate timing, and high-quality plating processing can be stably performed, so that the yield is improved. Can contribute to productivity improvement.
[0040]
(Embodiment 3)
FIG. 6 is a diagram showing a plating apparatus according to Embodiment 3 of the present invention. In FIG. 6, one frame holder 21 is disposed in each unit section. The frame detection cameras 11a, 11b, and 11c are disposed on the entrance side of the preprocessing unit 3, the plating processing unit 10, and the postprocessing unit 4, respectively. The first preprocessing stage 13a of the preprocessing unit 3 has a length of 3 unit sections. When the last lot passes through the preprocessing stage 13a and the vacancy continues after that, the power supply 13a is turned on when the last frame holder 21 enters the preprocessing stage 13a based on the detection result of the frame detection camera 11a. You are instructed to pass three frames of current. Thereafter, when there is one tact feed, the preprocessing stage 13a is instructed to flow current for two frames because one empty frame holder comes in. Further, when there is a next tact feed, a current for one frame is supplied, and at the next tact feed, an instruction of current off or weak current is issued.
[0041]
Also in the plating processing unit 10 and the post-processing unit, as in the pre-processing unit, it is possible to accurately grasp the number of frames staying at each processing stage and set an appropriate current.
[0042]
In addition, when the distance between the frame detection camera and the target processing stage is long and there are several processing stages in between, the timer means is used to enter the processing stage after a predetermined tact feed has elapsed. A current corresponding to the number of staying frames is allowed to flow.
[0043]
With the above configuration, even when the plating apparatus is paused and restarted, the current can flow at the correct timing, and the current value is an appropriate current value corresponding to the number of frames remaining in the processing stage. It can be. In addition, even when a frame is dropped in the middle, it is possible to accurately grasp the number of frames staying in the processing stage and set an appropriate current value.
[0044]
(Embodiment 4)
FIG. 7 is a diagram showing how to issue an instruction when frame monitoring sensors are arranged at the entrance and the exit of the preprocessing unit. (A) is the case of the sensor arrange | positioned at an entrance, (b) is the case of the sensor arrange | positioned at an exit. When the sensor detects the passage of the frame, it sends a signal to the sequencer to instruct current output to the rectifier as the power source. When the sensor detects no frame, an off signal or a weak current output signal is sent, and no processing is performed in the processing stage.
[0045]
Further, when the exit sensor detects no frame, the sequencer issues a stop instruction signal to turn off the rectifier or set a weak current output. While the outlet sensor detects the passage of the frame, the rectifier is turned on to instruct current continuation.
[0046]
As described above, the lot end may not be detected only by the exit sensor, but the lot end may be detected by the frame detection sensor arranged at the exit, and an off signal or a weak current signal may be instructed to the rectifier.
[0047]
With the above configuration, it is possible not only to flow an appropriate current to each processing stage in a timely manner, but also to reliably manage the number of processed products delivered.
[0048]
Although the embodiments of the present invention have been described above, the embodiments of the present invention disclosed above are merely examples, and the scope of the present invention is not limited to these embodiments. The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.
[0049]
【The invention's effect】
By using the plating apparatus of the present invention, it is possible to reliably grasp the number of processed products arriving at the entrance of the plating apparatus, and to provide an appropriate current for forming a predetermined plating film thickness without causing a shift in the timing of current application. It can flow. Further, the end of the apparatus can be improved by accurately detecting the lot end and preventing the electrode from being replaced with a noble metal by passing a weak current when the plating process is not performed. Furthermore, by actually grasping the number of processed products sent out from the outlet side, the management of the plating process can be made more reliable.
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of a layout of a plating apparatus in Embodiment 1 of the present invention.
FIG. 2 is a diagram illustrating a relationship among a transport device, a processing device, and a frame that is a processed product in the first embodiment.
FIG. 3 is a block diagram showing the relationship between components in the first embodiment.
FIG. 4 is a diagram illustrating a database stored in a storage unit.
FIG. 5 is a diagram showing an outline of the operation of a plating apparatus in Embodiment 2 of the present invention.
FIG. 6 is a diagram showing an outline of the layout of a plating apparatus in Embodiment 3 of the present invention.
7A and 7B are diagrams showing an outline of the operation of a plating apparatus in Embodiment 4 of the present invention, where FIG. 7A shows the operation of the inlet sensor, and FIG. 7B shows the operation of the outlet sensor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Plating apparatus, 2 Inloader, 3 Pre-processing part, 4 Post-processing part, 5 Out loader, 10 Plating process part (Plating bath), 11 Frame number monitoring camera, 12, 12a Power supply (rectifier), 13, 13a, 13b Processing Stage, 15 Processed product (frame), 20 Transport device, 21 Processed product holder (frame holder), 25 Unit division, 31 Tact feed counter (series number specifying unit), 32 Arithmetic unit, 33 Current automatic setting unit, 34 Storage unit, 35 manual input unit.

Claims (8)

A transport apparatus divided into unit sections along a traveling direction; and a processing apparatus partitioned into processing stages having a length corresponding to one or more unit sections of the transport apparatus, the transport apparatus including the unit sections A plating apparatus of a tact feed method that holds a processed product in a processed product holder disposed inside and sequentially and intermittently feeds the inside of the processing apparatus,
A power source for supplying a current for processing provided in each processing stage;
A processing product number detection means that is disposed on the inlet side of the plating apparatus and detects the number of processed products sent to the plating apparatus;
Corresponding to the processing product input sequence, series number specifying means for specifying the series number attached to the processing product for each unit classification,
Storage means for storing preliminarily input information on the processing stage, information on the type of the processed product and plating area in the type, and
The plating area in the processing stage is calculated based on the number of the detected processing products, the type of the processing product to which the processing product of the specified series number belongs and the plating area of the type, and information on the processing stage. Calculating means for calculating a plating current in the processing stage;
A plating apparatus comprising: an automatic current setting means for automatically setting the calculated current and causing the current to flow through the power source. The plating apparatus according to claim 1, wherein a plurality of the processed product holders are arranged in parallel in the unit section, and each processed product holder can hold one processed product. The plating apparatus according to claim 1, wherein one processed product holder is arranged in the unit section, and each processed product holder can hold one processed product. The processed product number detection means detects whether or not the arranged processed product holders are arranged for each row along the traveling direction, and whether or not the processed products are held in the processed product holders of the row. The plating apparatus in any one of -3. The plating apparatus according to claim 1, wherein the series number specifying unit is a counter that counts the tact feed number from a reference time of operation of the plating apparatus. The plating according to any one of claims 1 to 5, further comprising timer means for starting to flow the current to the power source of the processing stage after a predetermined tact feed number has elapsed from the time when the number of processed products is detected by the processed product number detecting means. apparatus. The apparatus further comprises a lot end detection means for detecting the end of a lot composed of the same kind of the processed product, and the current automatic setting means is configured to generate a predetermined weak current based on a lot end detection signal from the lot end detection means. The plating apparatus according to any one of claims 1 to 6, wherein a current flows through the power source. The plating apparatus in any one of Claims 1-7 further equipped with the completion processing product number detection means which detects the number of the processing products sent out from the said plating apparatus in the exit of the said plating apparatus.

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