KR20120006271A - Method for aligning semiconductor package aggregate - Google Patents

Abstract

PURPOSE: A semiconductor package aggregate alignment method is provided to automatically set a position correction weighted value in a preliminary alignment part by considering an alignment error value, thereby rapidly and accurately performing an alignment process of a package aggregate. CONSTITUTION: A position value with respect to the central point of a chuck table is calculated(S1). A package aggregate in which an alignment process is completed is mounted on the chuck table(S2). A position value with respect to a reference mark of the package aggregate is acquired(S3). An alignment error of the chuck table and the package aggregate is calculated(S4). A position correction weighted value of a preliminary alignment part is established(S5).

Description

Method for Aligning Semiconductor Package Aggregate

The present invention relates to a method of aligning a semiconductor package assembly in an apparatus for manufacturing a semiconductor package, and more particularly, to a semiconductor package assembly (hereinafter referred to as a package assembly) in which a plurality of semiconductor packages are arranged in a lattice form. The present invention relates to a semiconductor package assembly alignment method for aligning a package assembly to an accurate process position in a semiconductor package manufacturing apparatus such as a singulation device for cutting into semiconductor package units.

As is well known, a semiconductor package attaches a plurality of semiconductor chips having high integrated circuits such as transistors and capacitors to a rectangular plate-shaped lead frame, and connects them to the pads of the lead frame through a wire bonding process. After molding the resin paper, the semiconductor package on the lead frame is cut into individual packages by singulation.

In recent years, as the types of semiconductor packages have been diversified, new packaging technologies for manufacturing semiconductor packages by forming semiconductor packages on circular leadframes, and then singulating the package assemblies into individual semiconductor package units have been developed. Is being developed.

In general, a semiconductor package singulation apparatus mounts a package assembly on which semiconductor packages are formed on a chuck table, and then cuts the package assembly into individual semiconductor package units while the cutting blade and the chuck table move relative to each other. The blade is configured to perform a cutting operation without touching the chuck table while passing through a blade escape groove formed on the chuck table to coincide with the cutting line of the package assembly.

However, if the cutting line of the package assembly seated on the chuck table does not coincide with the blade escape groove of the chuck table, when the cutting blade performs the cutting process along the cutting line of the package assembly, the cutting blade blade faces the surface of the chuck table. Excessive cutting blades are damaged while colliding with each other, and semiconductor packages are not cut to a precise shape, thereby causing a problem of poor processing.

Therefore, when the package assembly is seated on the chuck table, the operation of aligning the package assembly so that the cutting line of the package assembly exactly matches the blade escape groove of the chuck table is necessarily involved.

In the related art, before the package assembly is seated on the chuck table, the center of the package assembly in the preliminary alignment unit is aligned so that the center of the package assembly transport picker (hereinafter referred to as 'collective picker') is exactly aligned, and then the aggregate picker is aligned. The completed package assembly is picked up and guided to a designated position on the chuck table while the package assembly is seated on the chuck table.

However, even if the center position between the package assembly and the collective picker is picked up in the preliminary alignment unit as accurately as described above, when the collective picker mounts the package assembly on the chuck table, due to mechanical tolerances between the collective picker and the chuck table, etc. The cutting line of the package assembly does not exactly coincide with the blade escape groove of the chuck table.

In order to solve this problem, conventionally, before the cutting process of the package assembly, a package assembly or a corresponding dummy is placed on the chuck table, and the vision camera located above the chuck table faces each other on the upper surface of the chuck table. The operator visually checks whether the lines coincide with each other by photographing the reference line connecting two marked reference points and the cutting line of the package assembly or dummy.

If the alignment error between the reference line identified by the operator and the cutting line of the package assembly is larger than the allowable range, the operator checks the degree of distortion and adjusts the position correction weight of the package assembly in consideration of the degree of the operator misalignment in the preliminary alignment unit. Set it.

However, when checking the alignment error of the chuck table and the package assembly as described above and setting the position correction weight in the preliminary alignment unit in consideration of this error, it is possible to measure exactly how much the alignment error value between the chuck table and the package assembly is. There was no criterion that could be used, and there was no way to receive the alignment data value from the cutting process and use it to align the pre-alignment. Therefore, in the related art, setting of the position correction weight has to be done by manually performing the repetitive alignment operation according to the operator's experience, which causes a lot of time and effort in the alignment, thereby reducing productivity. There is.

The present invention is to solve the above problems, an object of the present invention is to accurately calculate the alignment error between the chuck table and the package assembly automatically when the package assembly is seated on the chuck table, and the calculated alignment error value The present invention provides a method of aligning a semiconductor package assembly, which enables the preliminary alignment unit to automatically set a position correction weight so that the alignment of the package assembly can be performed quickly and accurately.

In order to achieve the above object, the present invention provides a pre-alignment unit for performing a primary alignment by correcting a position of a package assembly in which a plurality of semiconductor packages are formed in a non-cut state, and alignment in the pre-alignment unit. An aggregate picker for picking up and conveying the completed package assembly, a chuck table on which a package assembly conveyed by the aggregate picker is seated, and a blade escape groove corresponding to a cutting line of the package assembly is formed on an upper surface thereof; A method of arranging package assemblies in a semiconductor package assembly processing apparatus including a vision camera installed in the apparatus, the method comprising: (a) a position value of a center point of the chuck table by photographing a reference point displayed on an upper surface of the chuck table by a vision camera; Calculating a; (b) the aggregate picker picking up the aligned package assembly in a pre-alignment unit and placing the package assembly on the chuck table; (c) photographing a specific reference mark displayed on the package assembly on the chuck table by the vision camera to obtain a position value for the reference mark; (d) calculating an alignment error between the package assembly and the chuck table based on the position value of the center point of the chuck table calculated in step (a) and the position value of the reference mark obtained in step (c); and (e) setting the package assembly position correction weights in the preliminary alignment unit based on the alignment error calculated in step (d).

A pre-aligner for correcting the position of the package assembly in which the plurality of semiconductor packages are formed in a non-cut state and performing primary alignment, and an aggregate picker for picking up and transporting the package assembly in which the pre-alignment is completed; A package assembly processing apparatus including a chuck table on which a package assembly conveyed by the assembly picker is seated, a cutting line of the package assembly and a blade escape groove corresponding to the package assembly are formed on an upper surface thereof, and a vision camera installed on the chuck table. A method of aligning package assemblies in a method comprising the steps of: (a) an aggregate picker picking up a package assembly that has been aligned in a preliminary alignment unit and placing the package assembly on the chuck table; (b) the vision camera photographing a specific reference mark displayed on the package assembly on the chuck table to obtain a position value for the reference mark; (c) calculating, by the vision camera, a position value of the center point of the chuck table by photographing the reference point displayed on the upper surface of the chuck table; (d) calculating an alignment error between the package assembly and the chuck table based on the position value of the reference mark obtained in step (a) and the position value of the center point of the chuck table calculated in step (c); (e) providing a semiconductor package assembly alignment method comprising setting a package assembly position correction weight in the preliminary alignment unit based on the alignment error calculated in step (d).

According to the present invention, the position value with respect to the center point of the chuck table can be calculated through the reference point provided on the chuck table, and the degree of alignment error of the package assembly seated on the chuck table can be calculated accurately based on this center point. Therefore, the position correction weight in the preliminary alignment unit can be set accurately and quickly on the basis of the calculated alignment error value.

1 is a plan view schematically illustrating a main configuration of an embodiment of a semiconductor package singulation apparatus as an example of a semiconductor package processing apparatus for performing a semiconductor package assembly alignment method according to the present invention.
FIG. 2 is a plan view illustrating an example of an operation performed in a sawing step of the semiconductor package singulation device of FIG. 1.
3 is a flow chart showing an embodiment of a semiconductor package assembly alignment method according to the present invention.
4 and 5 are plan views schematically illustrating a process of detecting an alignment error between the chuck table and the package assembly by applying the package assembly alignment method of the present invention in the semiconductor package singulation device of FIG. 1.

Hereinafter, exemplary embodiments of a semiconductor package assembly alignment method according to the present invention will be described in detail with reference to the accompanying drawings.

First, the configuration and operation of a semiconductor package singulation apparatus for performing the semiconductor package assembly alignment method according to the present invention will be described with reference to FIGS. 1 and 2 as follows.

1 and 2, a semiconductor package singulation device includes a loading unit 10 supplied with a circular package assembly W having a plurality of semiconductor packages arranged in a lattice form, stored in a magazine M; The package assembly W carried by the loading unit 10 is seated and aligned, and the package assembly W is transported from the loading unit 10 onto the preliminary alignment unit 30. The conveying robot 20, the sawing processing part 60 in which the package assembly W conveyed from the said preliminary sorting part 30 is cut into individual package units, and the package assembly in the said preliminary sorting part 30 Vacuum suction of W) to the sawing processing unit 60 to convey it to the sawing processing unit 60, and vacuum cleaning of the semiconductor package on the sawing processing unit 60 to clean the brush cleaning unit 81, the cleaning unit 82, and the vision. The unit picker 70 etc. conveyed to a test | inspection part (not shown) is comprised. The operation of each of these components is controlled by a controller (not shown) of the semiconductor package singulation device.

The preliminary alignment unit 30 moves the alignment table 31 on which the package assembly W is seated, and moves the alignment table 31 in any direction of XYZ-θ to adjust the position of the package assembly W. A driving unit (not shown) for correction and a vision camera 35 installed above the alignment table 31 to photograph the package assembly W on the alignment table 31 to detect a position. Here, the vision camera 35 is fixed to one side of the collective picker 50 and is configured to move together with the collective picker 50, but unlike this, the vision camera 35 is independent of the collective picker 50 in the X axis. It may also be configured to move along a direction.

The aggregate picker 50 vacuum-adsorbs the package assembly W on which the position correction has been performed on the preliminary alignment unit 30 to the sawing processing unit 60. Although not shown in the drawing, the aggregate picker 50 may pick up the package assembly W at a predetermined position of the preliminary alignment unit 30 and lower the package assembly W at a predetermined position of the chuck table 61. So that two positioning pins inserted into the positioning holes 32 of the preliminary alignment portion 30 and the positioning holes 64 of the chuck table 61 protrude downward from both sides of the lower surface of the collective picker 50. Formed.

The sawing processing unit 60 is a cutting blade for cutting the package assembly (W) on the chuck table 61 while moving relative to the chuck table (61), the package assembly (W) is seated ( 62 and a vision camera 63 provided above the chuck table 61.

The chuck table 61 is configured to be rotatable at any angle about an axis perpendicular to the movable block 65 moving along the Y axis guide frame 66. On the upper surface of the chuck table 61, blade escape grooves 61a (see FIG. 4) corresponding to the package cutting lines formed in the package assembly W in a lattice form are formed in a lattice form. The blade escape groove 61a functions to prevent the blade end of the cutting blade 62 from contacting the chuck table 61 when the cutting blade 62 cuts along the cutting line of the package assembly W. As shown in FIG. Therefore, when the cutting blade 62 and the chuck table 61 move relative to each other and the cutting blade 62 cuts the package assembly W on the chuck table 61 along a cutting line, the cutting edge of the cutting blade 62 is cut. The package assembly W is cut without passing through the blade escape groove 61a without being in contact with the chuck table 61.

Two positioning holes for inserting positioning pins (not shown) of the collective picker 50 into both side portions of the chuck table 61 to determine a seating position of the collective picker 50 with respect to the chuck table 61. 64 is formed facing each other. The positioning holes 64 serve as a reference point of the chuck table 61 when performing the package assembly alignment method of the present invention to be described later.

The semiconductor package singulation device configured as described above operates as follows.

First, the transport robot 20 draws out one of the package assemblies W stored in the magazine M of the loading unit 10, conveys it to the preliminary alignment unit 30, and the preliminary alignment unit 30. On the alignment table 31.

When the package assembly W is seated on the alignment table 31 of the preliminary alignment unit 30, a reference point of the package assembly W placed on the alignment table 31, for example, one side circumference Photographs of notches formed on the edges and fiducial marks on the upper surface of the package assembly W are taken to obtain position values for these reference points, and based on the position values, A position correction operation of the package assembly W is performed by adjusting the position of the alignment table 31 so that the center position coincides with the pickup center position of the assembly picker 50.

When the primary alignment of the package assembly W is completed in the preliminary sorting unit 30, the assembly picker 50 picks up the package assembly W on the alignment table 31 and the sawing processing unit 60. It moves to and lowers on the chuck table 61, and lowers the package assembly W on the chuck table 61. As shown in FIG. At this time, as the positioning pin (not shown) of the collective picker 50 is inserted into the positioning hole 64 of the chuck table 61, the collective picker 50 is connected to the chuck table 61 at a constant position. .

When the package assembly W is seated on the chuck table 61, the chuck table 61 moves in the Y-axis direction along the Y-axis guide frame 66 and is located below the cutting blade 62, and at this position. The cutting process of the chuck table 61 is performed along the cutting line of the package assembly W while the cutting blade 62 is relatively moved.

When the cutting process in the sawing processing unit 60 is completed, the unit picker 70 vacuum-adsorbs the semiconductor packages cut into individual semiconductor package units on the chuck table 61 to clean the brush cleaning unit 81 and the cleaning unit ( 82), and returned to the vision inspection unit (not shown) in this order.

On the other hand, the cutting line of the package assembly W seated on the chuck table 61 and the blade escape groove of the chuck table 61 in order for the cutting process of the package assembly W to be accurately performed in the sawing processing part 60. (61a) must match exactly or at least within tolerance. However, even if the position of the package assembly W is correctly corrected with respect to the pickup position of the aggregate picker 50 in the preliminary alignment unit 30, mechanical tolerances may exist between the aggregate picker 50 and the chuck table 61. Therefore, when the aggregate picker 50 puts the package assembly W on the chuck table 61, there may be a slight error.

Therefore, in the present invention, when the aggregate picker 50 puts the package assembly W on the chuck table 61, the controller (not shown) detects an alignment error between the package assembly W and the chuck table 61. By automatically setting the position correction weights in the preliminary alignment unit 30 based on the detected alignment error value, the package assembly W is accurately corrected when the package assembly W is subsequently mounted on the chuck table 61. A method of arranging package assemblies to be mounted on a chuck table 61 is provided.

The package assembly alignment method of the present invention is performed in the step of setting the mounting position of the package assembly (W) relative to the chuck table (61) before performing the cutting processing process for the package assembly (W) as follows, or the package assembly It may be carried out during the cutting process for (W).

An embodiment of a package assembly alignment method according to the present invention will be described with reference to FIGS. 3 to 5 as follows.

First, before performing the cutting process on the package assembly W, the vision camera 63 photographs the reference point displayed on the upper surface of the chuck table 61 to form the center point O of the chuck table 61. The position value for is calculated (step S1). At this time, the reference point of the chuck table 61 photographed by the vision camera 63 is a plurality of reference marks (for example, two reference marks displayed to face each other) displayed on the upper surface of the chuck table 61. Can be Of course, instead of using a reference mark marked separately to improve the accuracy as a reference point of the chuck table 61, the two positioning holes 64 formed on the upper surface of the chuck table 61 are opposed to each other. The position of the center point O of the chuck table 61 may be obtained.

Next, the aggregate picker 50 picks up the package assembly W or the dummy corresponding to the package assembly from the preliminary sorting unit 30 and places it on the chuck table 61 (step). S2).

Subsequently, the chuck table 61 moves to the lower side of the vision camera 63, and the vision camera 63 photographs a specific reference mark F displayed on the package assembly W on the chuck table 61. The position value with respect to the reference mark F is acquired (step S3). The position information (X-axis direction distance and Y-axis direction distance information from the center point) of the reference mark F with respect to the center point Ow of the package assembly W is previously input to the controller (not shown). Accordingly, the controller (not shown) is located between the position value of the reference mark (F) of the package assembly (W) obtained by photographing by the vision camera 63 and the reference mark (F) and the center point (Ow) previously input. By the positional information, the center point Ow of the package assembly W on the chuck table 61 can be calculated, and the center point Ow of the package assembly W on the chuck table 61 can be calculated. And an alignment error between the center point O position value of the chuck table 61 calculated in the step S2 (step S4).

When the alignment error between the chuck table 61 and the package assembly W is calculated as described above, the controller (not shown) sets a position correction weight in the preliminary alignment unit 30 based on the alignment error value, thereby preliminary. The alignment unit 30 corrects the position in consideration of the alignment error occurring in the chuck table 61 in advance so that an alignment error does not occur when the package assembly W is seated on the chuck table 61 (step S5). .

As described above, if the alignment between the chuck table 61 and the package assembly W is completed before the cutting process for the package assembly W starts in earnest, the cutting process for the package assembly W is completed. It starts.

During the cutting process in the singulation device, the sawing processing unit 60 repeatedly performs the same steps as described above every time the package assembly W is seated on the chuck table 61. ) And the alignment error between the package assembly W, and if the alignment error is out of the setting range, the package assembly W is returned to the preliminary alignment unit 30 to recalibrate the position in consideration of the alignment error value. Conventionally, when the alignment error between the chuck table 61 and the package assembly W is out of the setting range, the singulation device is stopped, the error is corrected, and the singulation device is restarted. As described above, according to the present invention, even if the alignment error between the chuck table 61 and the package assembly W is out of the setting range, continuous operation can be performed without stopping the equipment, thereby improving productivity.

At this time, during the cutting process in the singulation device, the vision camera 63 photographs the reference point of the chuck table 61 to calculate the position of the center point O of the chuck table 61 (step S1). It does not necessarily need to be performed again, and the center point O position value of the chuck table 61 calculated in the initial position setting process may be used as it is.

In addition, during the cutting process in the singulation device, the controller accumulates log data on alignment errors between the chuck table 61 and the package assembly W calculated in step S4, and analyzes the accumulated log data. If the alignment error has a constant tendency, the preliminary alignment section 30 sets the package assembly W seated on the chuck table 61 by setting the position correction weight in the preliminary alignment section 30 before the alignment error is out of the setting range. It can be checked in advance by predicting mechanical misalignment of each component or continuously by making accurate alignment continuously without returning to.

As described above, according to the present invention, the position value of the center point O of the chuck table 61 is calculated based on the reference point photographed on the chuck table 61, and on the chuck table 61 based on the center point O. The alignment error value of the package assembly W seated at can be accurately calculated. Therefore, it is possible to accurately and quickly set the position correction weights in the preliminary alignment unit 30 based on the calculated misalignment value so that no alignment error occurs between the chuck table 61 and the package assembly W thereafter. have.

Meanwhile, in the above-described embodiment, after the vision camera 63 photographs the reference point of the chuck table 61 and calculates the position of the center point O of the chuck table 61 (step S1), the package assembly W is removed. It is seated on the chuck table 61 (step S2), and the specific reference mark F displayed on the package assembly W on the chuck table 61 is photographed to obtain a position value for the reference mark F. (Step S3). However, unlike this, the package assembly W is seated on the chuck table 61, and the vision camera 63 photographs a specific reference mark F displayed on the package assembly W on the chuck table 61. After obtaining the position value for the reference mark F, the vision camera 63 may photograph the reference point of the chuck table 61 to calculate the center point O position of the chuck table 61.

The above-described embodiment of the method for arranging package aggregates exemplifies a method of arranging the package aggregates W in a singulation device for cutting the package aggregates W into individual package units. In addition to the singulation device, the same or similar application may be applied to any semiconductor package processing device that handles various kinds of package assemblies.

10: loading unit 20: carrier robot
30: preliminary alignment unit 31: alignment table
32: positioning hole 35: vision camera
50: collective picker 60: cutting processing unit
61: chuck table 61a: blade escape groove
62: cutting blade 64: positioning hole
W: package assembly F: reference mark
O: center of chuck table Ow: center of package assembly

Claims (14)

A pre-aligner for correcting the position of the package assembly in which the plurality of semiconductor packages are formed in a non-cut state and performing primary alignment, and an aggregate picker for picking up and transporting the package assembly in which the pre-alignment is completed; A package assembly processing apparatus including a chuck table on which a package assembly conveyed by the assembly picker is seated, a cutting line of the package assembly and a blade escape groove corresponding to the package assembly are formed on an upper surface thereof, and a vision camera installed on the chuck table. In order to sort a collection of packages,
(a) calculating a position value of the center point of the chuck table by photographing the reference point displayed on the upper surface of the chuck table by the vision camera;
(b) the aggregate picker picking up the aligned package assembly in a pre-alignment unit and placing the package assembly on the chuck table;
(c) photographing a specific reference mark displayed on the package assembly on the chuck table by the vision camera to obtain a position value for the reference mark;
(d) calculating an alignment error between the package assembly and the chuck table based on the position value of the center point of the chuck table calculated in step (a) and the position value of the reference mark obtained in step (c);
and (e) setting a package assembly position correction weight in the preliminary alignment unit based on the alignment error calculated in step (d).
The method of claim 1, wherein steps (a) to (e) are performed to set an initial position of a package assembly to be seated on the chuck table before the process of the package assembly on the chuck table is performed. A semiconductor package assembly sorting method, characterized in that.
The method of claim 1, wherein steps (a) to (e) are repeatedly performed during the process of processing the package assembly on the chuck table.
4. The method according to claim 3, wherein the alignment error data calculated in step (d) is accumulated during the process of processing the package assembly on the chuck table.
The method of claim 3, wherein when the alignment error calculated in step (d) is out of a setting range, step (e) is carried out, and the package assembly is returned to the preliminary sorting unit to adjust the position of the package assembly according to the set position correction weight. A method for aligning a semiconductor package assembly, wherein the semiconductor package assembly is rearranged.
The positioning pin according to any one of claims 1 to 5, wherein the reference points photographed by the vision camera in step (a) are formed to face each other on the chuck table, and protrude downward from the collective picker. And a plurality of positioning holes to be inserted.
The semiconductor package assembly alignment method of claim 1, wherein the reference point photographed by the vision camera in step (a) is a plurality of reference marks that are separately displayed on the chuck table.
A pre-aligner for correcting the position of the package assembly in which the plurality of semiconductor packages are formed in a non-cut state and performing primary alignment, and an aggregate picker for picking up and transporting the package assembly in which the pre-alignment is completed; A package assembly processing apparatus including a chuck table on which a package assembly conveyed by the assembly picker is seated, a cutting line of the package assembly and a blade escape groove corresponding to the package assembly are formed on an upper surface thereof, and a vision camera installed on the chuck table. In order to sort a collection of packages,
(a) an aggregate picker, picking up the completed package assembly in the pre-alignment unit and placing the package assembly on the chuck table;
(b) the vision camera photographing a specific reference mark displayed on the package assembly on the chuck table to obtain a position value for the reference mark;
(c) calculating, by the vision camera, a position value of the center point of the chuck table by photographing the reference point displayed on the upper surface of the chuck table;
(d) calculating an alignment error between the package assembly and the chuck table based on the position value of the reference mark obtained in step (a) and the position value of the center point of the chuck table calculated in step (c);
and (e) setting a package assembly position correction weight in the preliminary alignment unit based on the alignment error calculated in step (d).
9. The method of claim 8, wherein steps (a) to (e) are performed as steps for setting an initial position for a package assembly to be seated on the chuck table before processing is performed on the package assembly on the chuck table. A semiconductor package assembly sorting method, characterized in that.
9. The method of claim 8, wherein steps (a) to (e) are repeatedly performed during the process of processing the package assembly on the chuck table.
The semiconductor package assembly alignment method according to claim 10, wherein the alignment error data calculated in step (d) is accumulated during the process of processing the package assembly on the chuck table.
11. The method of claim 10, wherein if the alignment error calculated in step (d) is out of the setting range, step (e) is carried out, and the package assembly is returned to the preliminary sorting unit to adjust the position of the package assembly according to the set position correction weight. A method for aligning a semiconductor package assembly, wherein the semiconductor package assembly is rearranged.
The positioning pin according to any one of claims 8 to 12, wherein the reference points photographed by the vision camera in step (c) are formed to face each other on the chuck table and protrude downward from the collective picker. And a plurality of positioning holes to be inserted.
The method according to any one of claims 8 to 12, wherein the reference point photographed by the vision camera in step (c) is a plurality of reference marks that are separately displayed on the chuck table.

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