KR100325130B1 - Exposing tool for flexible ball grid array semiconductor package using a pin-hole alignment - Google Patents

Abstract

PURPOSE: An exposure apparatus for a flexible ball grid array(BGA) semiconductor package by using pin hole alignment is provided to shorten a time interval for aligning a mask and a film by using a mechanical type pin hole, and to improve an alignment error required by the flexible BGA by increasing precision of the pin hole. CONSTITUTION: An exposure light source is fixed in a portion over a mask(NM) to make predetermined circuit patterns on the mask exposed in a precise position of a flexible BGA film(11). A top plate is transferred together with the exposure light source, installed under the exposure light source to support the mask. A guide unit is installed to guide the film. A bottom plate(BP) is correspondingly coupled to the top plate. A pin(13) is installed near the center of the circumference of the mask to be coupled to a sprocket hole(12) of the film transferred for an exposure process. A pin hole(14) is formed in a corresponding position of the pin to receive the pin. A sensor(15) for calculating the number of the sprocket hole is installed under the bottom plate for guiding the film. The mask and the film are mechanically aligned.

Description

Exposing device for flexible ball grid array semiconductor package using pin hole alignment {EXPOSING TOOL FOR FLEXIBLE BALL GRID ARRAY SEMICONDUCTOR PACKAGE USING A PIN-HOLE ALIGNMENT}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus for a flexible ball grid array semiconductor package using pinhole alignment. More specifically, the present invention relates to a pin for protruding adjacent to a mask so as to accurately position a mask at a predetermined position on a film. By mechanically coupling to the sprocket holes formed at intervals to align the glass mask and film, the alignment time of the mask and film is greatly reduced, and the reliability of the alignment is improved, so that the pinhole alignment is used to increase the productivity and yield of the final circuit. An exposure apparatus for a flexible ball grid array semiconductor package.

In general, a semiconductor package is to protect semiconductor chips such as single devices and integrated circuits formed by stacking various electronic circuits and wirings from various external environments such as dust, moisture, electrical, and mechanical loads, and optimize electrical performance of the semiconductor chips. In order to maximize, it means that the signal input / output terminals to the main board are formed using a lead frame or a printed circuit board (PCB), and molded using an encapsulation means.

These semiconductor packages are in the trend of thin and small in order to support them according to the advanced integration technology of semiconductor chips and the miniaturization of electronic devices, and an array type semiconductor package using a lead frame and a pin grid array Increasingly, demand for PGA semiconductor packages and ball grid array (BGA) semiconductor packages (hereinafter referred to as 'BGA packages') is increasing.

The BGA package was developed to accommodate high-density semiconductor chips and multi-pinning needs, and is a surface mount type (SMT) having a plurality of solder balls arranged in a constant shape on the bottom for mounting on a main board. One kind of package.

In addition, the flexible BGA semiconductor package (hereinafter referred to as 'fleXBGA package') can produce a large number of signal outgoing terminals even in a limited area compared to conventional BGA packages, thereby miniaturizing, integrating, and It is the next generation package technology that can pursue pinning.

Prior to assembling of the fleXBGA package, a circuit having a predetermined pattern formed on a film is preceded. A general manufacturing method of the circuit will be described below.

1. As a punching step, a rectangular sprocket hole is drilled at regular intervals on the edge of the polyimide film that is the material of the fleXBGA package circuit.

2. Copper coating step, applying copper foil on the punched film.

3. A circuit pattern forming step, after applying a photoresist on the film, the ultraviolet light is emitted to the photosensitive material of the film through a glass mask in which a predetermined circuit pattern is formed. An exposing step, a developing step of removing an area exposed to ultraviolet light, and a copper applied to the entire film using a chemical etching solution to remove an area not corresponding to a predetermined circuit pattern. A predetermined circuit pattern is formed on the film through etching.

4. In the nickel / gold plating step, nickel and gold are plated on the formed circuit pattern.

In general, the exposure process during the circuit manufacturing process as described above has the greatest influence on the yield and productivity of the final circuit, and means for accurately aligning the mask and the film so that a predetermined circuit pattern is formed at a predetermined position of the film. This is known as a major factor affecting yield and productivity. Until now, the alignment method has been a feedback-type electronic system in which the position of the mask is adjusted little by little until the circuit pattern of the mask is located in the desired area of the film while monitoring the reference point marked on the film using a camera.

As can be seen from the plan view of the conventional mask OM shown in Fig. 1, only one unit of the circuit pattern CP is formed in the conventional glass mask. This is because the exposure apparatus for the conventional flexible ball grid array (fleXBGA) semiconductor package has a low level of confidence in the alignment tolerance of the mask and the film when the mask and the film are aligned using a camera to expose the film. This is because only one unit of the circuit pattern CP can be processed. Actually, the alignment tolerance required by the fleXBGA package is 10 µm, whereas the error of the conventional electronic method using a camera has a confidence level of about 20 µm.

However, when aligning a mask and a film in which only one unit of circuit pattern is formed by using a conventional camera as described above, even though the one-time exposure capability is limited to one unit due to the limit of confidence level of alignment, the conventional electronic method The alignment device took more than 20 seconds to align the mask and film correctly, and the alignment error did not fully meet the tolerances required by the fleXBGA package. Thus, the productivity and yield of the final circuit was significantly lower due to the limitation of alignment time and single exposure capability. In addition, since complicated electronics are used for accurate alignment of the exposure apparatuses, and more expensive electronics are used to perform this, the cost of the exposure apparatus is very expensive and the work time for the maintenance of the parts is considerably required. Several problems were raised.

The present invention has been made to solve the conventional problems as described above, the first object of the present invention can reduce the alignment time of the mask and the film during film exposure by using a pin hole of the mechanical method rather than the electronic method. To provide an alignment device.

The second objective is to improve the accuracy of the pinholes to provide alignment reliability beyond the tolerances required by the fleXBGA package.

The third object is to improve the single exposure capability of the exposure apparatus by changing the structure of the mask to expose more than one unit in one exposure through improved reliability of alignment errors.

A fourth object of the present invention is to provide an exposure apparatus having a low cost and easy maintenance of the exposure apparatus through a simple alignment method of a mechanical method using a pin hole.

1 is a plan view of a conventional mask.

2 is a plan view of the mask of the present invention.

Figure 3 is a plan view of the mask with the inner plate and top plate supporting the mask removed to show the mask positioned on the film by the pinhole alignment of the present invention.

Figure 4 is a cross-sectional view of the pinhole of the present invention to show the coupling structure of the mask and the pin and the bottom plate of the present invention.

Figure 5 is a bottom view showing a coupling relationship between the inner plate and the upper plate for supporting the mask of the present invention.

Figure 6 is a plan view of the bottom plate of the present invention.

7 is a schematic configuration diagram of an exposure apparatus for a flexible ball grid array semiconductor package using pinhole alignment according to the present invention.

Explanation of symbols on main parts of drawing

EX: Exposure device UV: Ultraviolet light source

OM: Conventional mask NM: Mask of the present invention

CP: Circuit Pattern TP: Top Panel

IP: Inner Panel BP: Lower Panel

11: film 12: sprocket hole

13: pin 14: pin hole

15: sensor 21: mask fixing plate

24: upper guide shaft hole 25: lower guide shaft hole

27: vacuum hole 32: piston

In order to achieve the above object, an exposure apparatus for a fleXBGA package using a mechanical pinhole alignment device according to the present invention has a pin 13 masked to be coupled to a sprocket hole 12 of a film 11 to be transported for exposure. (NM) is formed protruding adjacent to the circumferential center, the pin hole 14 is formed in the corresponding position of the pin 13 to receive the pin 13, the sensor for calculating the number of sprocket holes 12 15 is formed on the film guide lower plate (BP).

In the present invention, through the punching step described in the circuit fabrication process, the pin 13 is inserted into a position coinciding with the sprocket hole 12 formed on the outside of the film (generally referred to as 'material') in the form of rectangular spaces. As a result, the mask NM and the film 11 are mechanically aligned, which is referred to as a 'pin hole alignment device'.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, an exposure apparatus for a fleXBGA package using pinhole alignment according to the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can more easily understand the present invention. same.

As shown in FIG. 3, the combined state of the film and the mask is shown in a plan view, the mask of the exposure apparatus using the pinhole alignment of the present invention is the mask and the film when the pin 13 is coupled to the sprocket hole 12 formed in the film In order to automatically align, the pin 13 formed with the center portion of the mask NM in which the three-unit pattern is formed to remove the concave portion and protrude into the concave portion is a sprocket hole 12 of the polyimide film 11. ) Is combined.

Here, eight fins 13 each of four are shown in the concave portion of the mask NM, but the number and arrangement of the fins may be arbitrarily changed.

As shown in cross-sectional view to show the coupling structure of the mask and the pin and the lower plate of the present invention in Figure 4, the mask NM of the present invention is fixed to the upper inner plate (IP) and the sprocket in the center portion of the mask A pin 13 is installed that engages the hole 12.

The lower plate BP is formed with a pin hole 14 at a position corresponding to the pin 13 so as to receive the pin 13 of the upper plate, and the sprocket hole 12 is calculated at the center lower portion between the pin holes 14. The sensor 15 is installed, the transferred film 11 is located on the upper surface of the lower plate (BP).

The sensor hole 16 of the sensor 15 is formed in parallel with the pin hole 14 of the lower plate BP, and the sensor 15 is also provided in a straight line under the lower plate in parallel with the sensor hole 16.

The mask NM is fixed to the inner plate IP with the bolt 36 using the mask fixing plate 21.

As shown in the bottom view of FIG. 5, the mask NM is coupled to the inner plate IP through the plurality of mask fixing plates 21, and the inner plate IP is fixed to the upper plate TP. The upper guide shaft hole 24 is formed in the upper plate TP to raise and lower the upper plate.

As shown in the plan view in FIG. 6, the lower plate BP is provided with a vacuum plate 26 to fix the transferred film in place. The vacuum plate 26 is formed with a plurality of vacuum holes 27 such that a vacuum source (not shown) acts on the film so that the film adheres to the upper surface of the lower plate.

The vacuum plate 26 and the vacuum hole 27 fix the film 11 by vacuum when the pin 13 is inserted into the sprocket hole 12 of the film 11 during the alignment and exposure process. It is a component that prevents the film 11 from rocking. In addition, the lower plate BP is formed with a lower guide shaft hole 25 through which the lower moving shaft is guided to raise and lower the upper plate TP. In addition, the sensor hole 16 for installing the sensor 15 for calculating the sprocket hole 12, the pin hole 14 for accommodating the pin 13 in alignment, and a vacuum plate for preventing the film from shaking. 26 and a vacuum hole 27 exist.

On the other hand, with reference to Figures 2 and 4 will be described the structure of the glass mask applicable to the exposure apparatus for fleXBGA package using the pinhole alignment according to the present invention.

The mask NM according to the present invention shown in FIG. 2 has a structure in which a part of the mask corresponding to the pin position is removed so that the pin can be positioned at a position coinciding with the sprocket hole formed in the film. Since the mask can be manufactured in half the size of a conventional mask (OM), it has the advantage of reducing the production cost. In addition, more than three units of circuit pattern CP can be formed on one mask NM.

This is because the alignment method according to the present invention improves the reliability of the alignment tolerance, and the alignment tolerance required by the fleXBGA package is 10 µm, whereas the mechanical error using the pinhole of the present invention is applicable to the next generation. It has a confidence level of about 5 μm (the error of the electronic method using a conventional camera is about 20 μm). This improvement in the level of confidence in the alignment error greatly improves the single exposure capability from one unit to three units, which naturally increases the productivity of the final circuit for the flexible ball grid array semiconductor package.

The operation principle of the exposure apparatus EX having such a configuration will be described with reference to FIG.

As shown on the right side of the center line of FIG. 7, the film 11 is brought into the exposure apparatus EX while the inner plate IP, the upper plate TP, and the ultraviolet light source UV are raised. During feeding, the sensor 15 detects and calculates the number of sprocket holes 12 of the film to be exposed through the sensor holes 16 to confirm the exact position and conveying length of the film 11. As such, the sensor for checking the conveying length of the film sends a signal to a controller (not shown) to stop the film conveying apparatus, which stops the film conveying apparatus. At this time, when a vacuum source (not shown) is operated, a vacuum is applied to the bottom surface of the film through the vacuum hole 27 of the vacuum plate 26 and the film is maintained at a predetermined position on the upper surface of the lower plate BP.

Thereafter, when the piston 32 is lowered, the lifting plate 33 is lowered, and the lower guide shaft 34 is lowered by the lowering of the lifting plate 33, as shown on the left side of the center line of FIG. In addition, the upper guide shaft 35 supported by the lower guide shaft 34 is also lowered so that the upper plate TP to which the mask NM and the pin 13 are attached is lowered toward the lower plate BP. The pin 13 slowly enters the pin hole 14 through the sprocket hole 12 to perform alignment of the mask and the film. At this time, the mask NM is not completely in contact with the film 11 but is spaced apart by a predetermined interval, and the film 11 is completely in contact with the lower plate BP by vacuum. Thus, after alignment of a mask and a film is completed, an exposure process is performed using an ultraviolet light source (UV).

When the exposure process is completed, the mask NM is raised on the lower plate BP in the reverse order to the lowering operation. That is, the lifting plate 33 is raised in accordance with the up operation of the piston 32, the lower guide shaft 34 is raised in accordance with the lifting of the lifting plate 33, and the lower guide shaft 34 is When raised, the upper guide shaft 35 supported in contact with the lower guide shaft 34 is raised. When the upper plate TP is sequentially raised by the rising of the upper guide shaft 35, the pin 13 is pinned. It is raised from the hole 14 and completely separated from the sprocket hole 12 of the film 11, as shown in the right state of FIG. After that, the vacuum supply to the vacuum plate 26 is stopped to release the vacuum deposition of the film, and the film 11 having the predetermined circuit pattern CP is transferred to the next subsequent process.

By repeating the above steps in succession, the exposure process is completed during the circuit fabrication process.

As described above, although the present invention has been described with reference to the above embodiments, various modifications may be made by those skilled in the art without departing from the scope and spirit of the present invention.

Therefore, according to the present invention, first, it provides an alignment method that can reduce the time required to align the mask and the film using a mechanical pinhole.

Second, by improving pinhole accuracy, alignment errors provide reliability beyond the tolerances required by the fleXBGA package.

Third, there is an effect that can improve the one-time exposure ability through the improvement of the reliability of the alignment error.

Fourth, through the simple alignment method of the mechanical method using a pin hole it is effective to reduce the cost of the exposure apparatus, and to facilitate maintenance.

While the alignment time required by the electronic method using a conventional camera is about 20 seconds, the alignment time by the mechanical method using the pinhole is about 3 seconds, which greatly shortens the alignment time and improves the reliability of the alignment. Productivity and yield of the exposure film is improved, thereby significantly reducing the manufacturing cost of the fleXBGA package.

Claims (5)

Fixed circuit pattern on the mask NM to be exposed to the correct position of the fleXBGA package film 11 for the exposure process during the fabrication of the circuit for the flexible ball grid array semiconductor package (fleXBGA package). An exposure light source UV provided, an upper plate TP disposed below the exposure light source UV to support the mask NM and moving together with the exposure light source, and a guide device for guiding the film to be exposed are formed. In the exposure apparatus for a flexible ball grid array semiconductor package (fleXBGA package) consisting of a lower plate (BP) corresponding to the upper plate (TP), The pin 13 protrudes adjacent the center of the circumference of the mask NM so as to be coupled to the sprocket hole 12 of the film 11 to be conveyed for exposure, A pin hole 14 is formed at a corresponding position of the pin to accommodate the pin 13, and a sensor 15 for calculating the number of sprocket holes 12 is installed in the film guide lower plate BP. An exposure apparatus for a flexible ball grid array semiconductor package using pinhole alignment, wherein the mask NM and the film 11 are mechanically aligned. 2. The exposure apparatus for a flexible ball grid array semiconductor package according to claim 1, wherein a concave portion is formed so that the protruding pins 13 are provided at the center portion of the mask NM in the circumferential direction of the film 11. . The inclined surface is formed around the mask NM to fix the mask NM by using a plurality of fixing plates 21 on the lower side of the inner plate IP coupled to the upper plate TP. An exposure apparatus for a flexible ball grid array semiconductor package using pinhole alignment, characterized in that formed. The flexible ball using pinhole alignment according to claim 1, wherein the lower plate BP has a vacuum plate 26 in which a vacuum hole 27 is formed to bring the transferred film 11 into close contact with the guide surface of the lower plate. Exposure apparatus for grid array semiconductor package. 5. The flexible plate according to claim 1, wherein the upper plate TP is lifted up or down by a lower guide shaft 34 installed to penetrate the lower plate BP. Exposure apparatus for ball grid array semiconductor package.