JP2934804B2 - Shape processing and processing method of lead frame for semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing and processing a lead frame for a semiconductor device.
Appropriate combination of different shape processing and processing process groups to form a linked shape processing and processing line, streamline the transfer work between the groups, prevent damage caused by transfer, and meet diversified quality and use conditions The present invention relates to a shape processing and processing method for a lead frame for a semiconductor device which provides a high quality lead frame corresponding to flexibility.

[0002]

2. Description of the Prior Art As shown in FIGS.
A thin strip material is mounted upstream of the shape processing device 48, and the thin strip material fed out in a horizontal state is placed in the first shape processing device 48.
In the intermittent conveying means 42, the processing is carried out to form a required shape while forming the leading end of the inner lead while intermittently supplying it to the integrated shape processing die apparatus 44 by mounting it on the press device 43 and winding means. Winding in a coil shape at 47; mounting the coiled thin strip material upstream of the heat treatment apparatus 59 and feeding it out toward the heat treatment apparatus 59; and bridging the thin sheet material by bridal means provided upstream and downstream of the heat treatment apparatus 59. A step of performing heat treatment for removing the retained internal residual stress by traveling in the heat treatment device 59 while applying a required tension to the strip, and winding the coil into a coil shape by the winding means 58; The coil-shaped thin strip material is mounted upstream of the plating apparatus 68 and is fed out to the plating apparatus 68.
2. Perform predetermined processing of plating processing 63 and post-processing 64,
A step of winding the coil-like thin strip material formed in the above-described step into a coil shape by the winding means 67;
8, and the thin strip material fed horizontally to the second shape processing device 88 is mounted on the press device 83 by the intermittent conveying means 82 provided in the second shape processing device 88. A batch process is performed in which processing is performed to form the tip of the inner lead into a required shape while intermittently supplying the inside of the processing mold device 84, and processing and processing are performed in the order of coiling by the winding means 87. A shape processing and processing method of a lead frame is generally used.

[0003]

In recent years, as semiconductor devices have become lighter, thinner and smaller, high quality and reliability have been required of lead frames for semiconductor devices. However, it is difficult to respond to the diversification of quality specifications required for lead frames by improving the metal sheet and strip material, and it is necessary to respond by diversifying the processing and processing of the lead frame forming process. In addition, there is a need for a method of manufacturing a lead frame for a semiconductor device that performs a flexible one-step processing and processing in which different types of processing and processing means can be connected to required positions and separation can be changed as needed. Furthermore, with the increase in the degree of integration of semiconductor devices, the number of circuit forming leads has increased, the lead width and the spacing between the leads have become finer, and the internal residue that has accumulated during the forming of thin strips, the forming of leads, and the coining process. There is a problem that stress and punch burrs and protrusions cause minute deformation during the forming and processing of the lead frame and lower the quality and yield of the lead frame, and it is necessary to perform intermediate processing in the middle of shape processing and processing. Sex had occurred.

Further, it is difficult to form a fine shape (the number of circuit forming leads is 160 or more) required for a lead frame only by press punching, and it is necessary to appropriately combine different shape processing methods and processing methods. was there. Furthermore, in the conventional method, each processing and processing step is wound in a coil shape, and the mounting and feeding are performed, so that the fine leads of the lead frame are bent, shifted, curled, etc. There is a problem in that an oxide film is formed, the number of post-processing steps is increased, and the quality and yield of the lead frame are reduced. The present invention has been made in view of such circumstances, and when performing predetermined shape processing and processing of a lead frame for a semiconductor device, the efficiency of each transport operation between the processing and processing steps, and the damage caused by transport. A lead frame for semiconductor devices that forms a shape processing and processing line that can easily combine different types of processing and processing steps, and that can respond to the flexibility of fine lead frame quality and diversification of specification conditions. The purpose of the present invention is to provide a shape processing and processing method.

[0005]

According to the present invention, there is provided a semiconductor device comprising:
In the method for processing and processing a lead frame for a semiconductor device according to the above aspect, the shape processing stage of the progressive die apparatus for forming the lead frame is divided into shape processing means having independent pressure driving means. A tension applying means for forming a plurality of shape processing steps by appropriately combining and removing internal residual stress accumulated in upstream shape processing in or between the shape processing steps. A group of heat treatment steps, a group of processing steps of electrolytic polishing and / or chemical polishing for removing punch burrs and projections generated in the upstream shape processing, a group of plating processing steps for metal-coating a required portion of the lead frame, and a space between leads. A loop controlled by a control device that maintains a required loop amount by performing at least one of a group of lead fixing processing steps by taping that prevents deformation and deviation of the lead. A required number of connections are made via a U-shape, and these constitute a one-step shaping and processing line, and the thin strip material fed vertically is supplied to the shaping and processing line. Then, while the thin strip material is moved in the line by the transport device provided in each of the processing and processing steps, required processing and processing are sequentially and continuously performed on the thin strip material, A lead frame is formed. According to the second aspect of the present invention, there is provided a method of processing and processing a lead frame for a semiconductor device.
In the described method, a part of the shape processing step group is replaced with a photo etching shape processing step group.

[0006]

In the method for processing and processing a lead frame for a semiconductor device according to the first and second aspects, the shape processing stages arranged in the conventional integrated progressive die apparatus have independent pressure driving means. Since it is divided into the shape processing means, the plurality of shape processing steps can be easily formed by appropriately combining the shape processing means. Further, since a plurality of shape processing process groups are divided and formed, a heat treatment process group, an electrolytic polishing and / or a chemical polishing process process group, a plating process process group, a lead fixing process process group such as taping, etc. It is easy to form various processing and processing lines of one process by appropriately combining the different types of processing steps. Furthermore, since a single-step shape processing and processing line is configured, the number of times the thin sheet material is wound up in a coil shape and fed out can be reduced, and waiting for processing can be eliminated. In the method of processing and processing a lead frame for a semiconductor device according to claim 2, since the processing step group is divided, the processing of the shape of the fine inner lead required for the shape and dimensions is performed by a different shape such as photo etching. A combination line of different shape processing can be easily replaced by a processing step group.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; FIG. 1 is a block diagram for explaining an outline of a method of processing and processing a lead frame for a semiconductor device according to a first embodiment of the present invention, and FIG. 2 is a plan view of a single lead frame formed by the same method. .

A method of processing and processing a lead frame for a semiconductor device according to a first embodiment of the present invention includes a first processing step group 10 and a second processing step group 11 as shown in FIG. And the heat treatment process group 1 arranged subsequently
2, an electropolishing step group 13, a multilayer plating step group (an example of a plating step group) 14, a tape adhesive step group (an example of a lead fixing step group) 15, and a third shape processing step group 16 Loop forming means 17 to 23 having a control device for controlling a process group of these processing and processing;
33, a line of shape processing and processing is constituted, and a thin strip material is unreeled from this line in a vertical state from the beginning, and the thin strip material travels in the line and has a required shape of the lead frame. Processing and processing are sequentially performed to form a lead frame having a predetermined quality specification. Hereinafter, these will be described in detail.

The first shape processing step group 10 forms and maintains an unwinding device 24 for intermittently feeding a strip-shaped strip material A wound in a coil upstream of the processing step group 10 and a constant loop amount. Loop forming means 17 and processing step group 10
An intermittent transport device 25 that feeds in accordance with the processing speed is arranged on both sides thereof, and the thin plate material A is sent to the processing step group 10. The first shape processing step group 10 includes a pressure drive unit (not shown) in which a processing stage for forming the outer lead 73, the inner and outer frames 70 supporting the outer lead 73, the pilot hole 75, and the like is shown in FIG. Divided into processing means,
It is configured in an appropriate arrangement. In the shape processing step group 10, the outer lead 73 is attached to the thin strip material A.
And the inner and outer frames 70 and pilot holes 75 for supporting the same, to obtain a thin strip material B on which a part of a lead frame (not shown) is formed. Also, the shape processing step group 1
The sheet strip B formed at 0 is formed by the loop forming means 18 disposed downstream of the processing step group 10 to form a loop of the sheet strip B maintaining a constant loop amount.

Next, the second shape processing step group 11 is adjusted to the processing speed of the processing step group 11 for intermittently feeding out the thin strip material B formed by the loop forming means 18 upstream of the processing step group 11. An intermittent transporting device 25 is disposed on both sides of the device, and the thin plate material B is sent to the processing step group 11. The second shape processing step group 11 includes an element mounting portion 71 in the center, suspension leads 74 and 76 for supporting the element mounting portion 71, as shown in FIG.
The processing stage for forming the inner lead 72 and the like is divided into independent pressure driving means (not shown), and is appropriately arranged. In the shape processing step group 11, an intermediate shape of a lead frame (not shown) is formed by additionally processing an element mounting portion 71 and an inner lead 72 having a shape of a connecting piece connecting a tip end portion of the thin strip material B. The obtained thin strip material C is obtained. The thin strip material C formed in the shape processing step group 11 maintains a constant loop amount by the loop forming means 19 arranged downstream of the processing step group 11.
To form a loop.

Next, the heat treatment step group 12 includes a transport device 26 for feeding the thin sheet material C formed by the loop forming means 19 upstream of the heat treatment step group 12 in accordance with the processing speed of the heat treatment step group 12. Arranged on both sides, the transport device 26
Has a bridal roll (not shown) that applies a required tension to the thin strip material C, and sends the thin strip material C to which a predetermined tension has been added to the heat treatment process group 12. The heat treatment step group 12 is provided with an oxidation prevention atmosphere furnace including means of a preheating section 27, a heating section 28, and a slow cooling section 29. In the heat treatment step group 12, the thin strip material C is supplied to the oxidation-preventive atmosphere furnace, and the internal residual generated by the first and second shape processing through the processing of the preheating unit 27, the heating unit 28, and the slow cooling unit 29. The strip material D from which the stress has been removed is obtained.
The strip material D treated in the heat treatment step group 12 forms a loop of the sheet strip material D maintaining a constant loop amount by the loop forming means 20 arranged downstream of the heat treatment step group 12.

Next, the electropolishing step group 13 transports the thin plate material D formed by the loop forming means 20 upstream of the electropolishing step group 13 according to the processing speed of the electropolishing step group 13 for feeding out the thin strip material D. The apparatus 25 is disposed on both sides of the apparatus, and the sheet strip D is sent to the electropolishing step group 13. The electropolishing process group 13 is provided with an electrolytic solution tank (not shown) and a power supply device for applying an electrolytic current to the thin strip material D.
In the electropolishing step group 13, the thin plate material D is supplied to the electropolishing step group 13, and an anodic electropolishing process is performed using a CrO ₃ system as an electropolishing liquid, and the first and second shape processing are performed. A thin strip material E from which protrusions such as punch burrs and projections are removed is obtained. The thin strip material E processed in the electropolishing step group 13 is maintained in a constant loop amount by the loop forming means 21 arranged downstream of the electropolishing step group 13.
To form a loop.

Next, the multi-layer plating process group 14 includes:
Loop forming means 21 upstream of multilayer plating process group 14
Conveying devices 30a to 30 that feed the thin sheet material E formed by the above in accordance with the processing speed of the multi-layer plating process group 14
The transfer devices 30a to 30c apply the required tension to the thin strip material E and send the thin strip material E to the multilayer plating process group 14. The multilayer plating process group 14 includes a power supply unit that applies a predetermined plating current to the contact surface of the thin strip material E, and a transport device 30a to 30c that transports the thin strip material E while restricting swing in a vertical state. A pre-processing means 31 for performing a pre-plating treatment and a base plating on the thin strip material E; a multilayer plating processing means 32 for performing a plating on a required portion of the thin-plate material E plated with the base;
It has a post-processing means 34 for performing a cleaning process. In the multi-layer plating process group 14, a pre-plating process and the formation of a base plating layer of copper, nickel, etc. are performed on a predetermined portion of the thin strip material E, and the thin plated strip material E is plated.
After a precious metal such as gold, silver, palladium or the like is multi-layer-plated, unnecessary portions such as copper are peeled off and washed to obtain a thin-plate strip E obtained by performing multi-layer plating on the thin-plate strip E. Thin strip material F processed in multilayer plating process group 14
Forms a loop with a constant loop amount by the loop forming means 22 arranged downstream of the multilayer plating process group 14.

Next, the tape-adhering step group 15 is provided with a conveying device that feeds the thin sheet material F formed by the loop forming means 22 upstream of the tape-adhering step group 15 in accordance with the processing speed of the tape-adhering step group 15. 35, a tape supply device 37 for supplying a tape 36 to be adhered to the thin strip material F, and a forming and processing device 40 having a forming means 38 and a thermocompression bonding means 39 for forming a required tape shape. The material F and the tape 36 are configured to adhere at the intersections. In the tape bonding step group 15, at a crossing position of the supplied thin strip material F and the tape 36, a tape of a predetermined shape is adhered to a required lead portion of the thin strip material F to obtain a thin strip material G to which the lead is fixed. . A loop of the thin sheet material G having a constant loop amount is formed by the loop forming means 23 disposed downstream of the tape adhesion step group 15.

Next, the third shape processing step group 16 includes:
A processing step group 1 for intermittently feeding out the thin sheet material G looped by the loop forming means 23 upstream of the processing step group 16.
An intermittent transporting device 25 for feeding in accordance with the processing speed of No. 6 is disposed on both sides of the intermittent conveying device 25, and the thin sheet material G is sent to the processing step group 16. The third shaping step group 16 includes independent drive (not shown) for removing the connecting piece connecting the tip of the inner lead 72, correcting the tip, punching such as depressing the element mounting portion 71, stamping, and bending. It is divided into shape processing means provided with the means and arranged appropriately. In the third shape processing step group 16, processing such as stamping and bending was performed on the distal end portion of the thin strip material G and the element mounting portion 71, and the required lead frame shape processing from which the connection pieces were removed was performed. Obtain a thin strip. Third shape processing step group 1
The thin strip material formed in step 6 is sequentially wound by a winding device 41 disposed downstream of the processing step group 16, or the third shape processing step group 16 is provided with an intermittent cutting means to form a single lead frame. Are connected to form a unit frame to obtain the lead frame.

As shown in FIG. 3, a method of processing and processing a lead frame for a semiconductor device according to a second embodiment of the present invention includes a first processing step group 301, an electrolytic polishing step group 302, It has a second shape processing step group 303 as an etching process, a multilayer plating processing step group 304, a tape adhesion step group 305, and a third shape processing step group 306, and these processing and processing step groups. Are connected via loop forming means 307 to 314 provided with a control device for controlling the shape processing and processing as in the first embodiment. In the first shape processing step group 301, while performing the shape processing of the lead frame while the thin strip material travels in the line,
After removing the punch burrs and protrusions generated by the processing, and performing a shape processing to form a fine inner lead portion by an etching method using a generally known dry film, a multilayer plating process step group 304, The processes of the lead fixing process step group 305 and the third shape processing step group 306 are sequentially performed to obtain a lead frame in which fine lead portions have predetermined quality specifications.

The method of processing and processing the lead frame for a semiconductor device according to the first and second embodiments is such that the thin strip material serving as the lead frame is vertically set and conveyed, and the intermediate portion of the line is moved to Since it is bent in a letter shape, the installation space for equipment is small. In addition, since the thin strip is transported in the vertical direction, it can be turned smoothly without giving a twist to the thin strip.

[0018]

As described above, the method for processing and processing a lead frame for a semiconductor device according to the first and second aspects is easily performed by the shape processing means provided with the pressure driving means having independent processing steps. Therefore, as compared with the conventional integrated type progressive die, it is possible to easily configure various shape processing steps and easily and quickly respond to the demand for diversification of the lead frame shape. Furthermore, different types of processing groups such as a heat treatment process group, an electrolytic polishing and / or chemical polishing process group, a plating process group, a lead fixing process group, etc. are easily connected between the groups or groups, so that various shapes in one process can be obtained. Since the processing and processing lines can be easily configured, it is possible to easily manufacture lead frames of various types and similar types in small quantities. Furthermore, the winding and thinning of the thin strip material is reduced, the number of times of feeding is reduced, and the waiting time for processing is reduced, so that damage such as deformation of the lead frame due to winding and feeding is reduced.
Rust and oxide film due to processing wait are reduced, and the yield of the post-process is improved to improve the quality of the lead frame. In addition, since the thin strip material serving as the lead frame is vertically set and conveyed, and the middle portion of the line is bent in a U-shape, the thin strip material is not subjected to an unnatural twist or the like.
There is an advantage that a turn can be made, and consequently the installation space of the equipment is reduced. In particular, in the method of processing and processing a lead frame for a semiconductor device according to claim 2,
Since the shape processing process group is divided, it is possible to easily replace the shape processing of fine inner leads, which require shape and dimensions, with a heterogeneous shape processing process group such as photoetching to form a combination line of different shape processing and processing. .

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an outline of a method of processing and processing a lead frame for a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a plan view of a single lead frame formed by the same method.

FIG. 3 is a block diagram illustrating an outline of a method of processing and processing a lead frame for a semiconductor device according to a second embodiment of the present invention.

FIG. 4 is a schematic explanatory view showing a conventional shape processing device.

FIG. 5 is a schematic explanatory view showing a conventional heat treatment apparatus.

FIG. 6 is a schematic explanatory view showing a conventional plating apparatus.

FIG. 7 is a schematic explanatory view showing a conventional shape processing device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 1st shaping process group 11 2nd shaping process group 12 Heat treatment process group 13 Electropolishing process group 14 Multilayer plating process group 15 Tape adhesion process group (lead fixing process process group) 16 3rd shaping process process Groups 17 to 23 Loop forming means 24 Unwinding device 25 Intermittent transporting device 26 Transporting device 27 Preheating unit 28 Heating unit 27 Slow cooling unit 30a to 30c Transporting device 31 Preprocessing means 32 Multilayer plating processing means 33 Loop forming means 34 Postprocessing means 35 Conveying Device 36 Tape 37 Tape Supply Device 38 Forming and Processing Means 39 Heat Compression Means 40 Forming and Processing Device 41 Winding Device 70 Inner / Outer Frame 71 Element Mounting Section 72 Inner Lead 73 Outer Lead 74 Suspended Lead 76 Suspended Lead 75 Pilot Hole 301 First Shape processing step group 302 Electropolishing step group 30 3 Second shape processing step group 304 Multi-layer plating processing step group 305 Tape adhesion step group 306 Third shape processing step group 307 to 314
Loop forming means A to G Thin strip material

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Muneya Shibata 2-10-1, Komine, Yawatanishi-ku, Kitakyushu-shi, Fukuoka Mitsui High-Tech Co., Ltd. (58) Field surveyed (Int. Cl. ⁶ , DB name) H01L 23/50 C23F 17/00

Claims (2)

(57) [Claims] 1. A shape processing stage of a progressive die apparatus for forming a lead frame is divided into shape processing means having independent pressure driving means, and the shape processing means is appropriately combined to form a plurality of shape processing means. Configure the process group,
A heat treatment step group provided with a tension applying means for removing internal residual stress retained in the upstream shape processing in the shape processing step group or between the shape processing step groups, punch burrs and projections generated in the upstream shape processing At least one of a group of steps of electrolytic polishing and / or chemical polishing for removing a metal, a group of steps of plating for metal-coating a required portion of the lead frame, and a group of steps of fixing a lead by taping to prevent deformation and deviation between leads. Are connected by a required number through a loop controlled by a control device that maintains a required loop amount, and these constitute a one-step shape processing and processing line connected in a U-shape. A thin strip fed in a vertical state is supplied to a shape processing and processing line, and the thin strip is fed to the processing and processing step group by a transfer device provided in each of the processing and processing steps. While traveling, it performed sequentially and continuously processed with the required shaping in the thin strip material, shaping and processing method of a semiconductor device lead frame and forming a desired lead frame. 2. A method for processing and processing a lead frame for a semiconductor device according to claim 1, wherein a part of said group of processing steps is replaced by a group of processing steps of photoetching.