JP3274507B2 - Package manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for inspecting the shape of an object and a method for manufacturing a package in which a semiconductor chip is sealed.
A technology that is particularly effective when applied to law.

[0002]

2. Description of the Related Art Conventionally, in a rectangular package in which a semiconductor chip is encapsulated by soldering a cap to a substrate on which the semiconductor chip is mounted, when the package is mounted on a mounting board, the package is mounted from the peripheral side. The protruding brazing material or the like may cause an accident to cover other electrodes disposed around the package mounting area of the mounting board. In order to prevent this, the external dimensions of the package are inspected to select non-defective / defective products. Dimensions are measured by measuring the length from one side to the other side of the package using a tool microscope or the like.

In a so-called surface mounting package, a plurality of electrodes are exposed on the back surface of a package and are soldered to electrodes of a mounting board via solder balls or the like. Center point and multiple electrodes (or solder balls formed on the electrodes)
Error of mask alignment and dimensional error due to sintering (when the substrate is made of ceramic)
Manufacturing errors are caused by such factors. Conventionally, the package in which a manufacturing error has occurred is conventionally aligned with the center point in the package mounting area of the mounting board with reference to the center point of the outer shape . The actual mounting position of the package was shifted.

Therefore, the maximum allowable dimensions of the package in the above-described dimension measurement are defined in advance in consideration of the maximum movement amount of the package due to the manufacturing error. That is, the maximum size of the package is determined by subtracting the maximum value of a possible manufacturing error from the size of the package mounting area.

[0005]

However, it has been clarified by the present inventors that the above-described technology has the following problems. In other words, since the maximum value of the possible manufacturing error is estimated in advance and the maximum allowable package size is set to be slightly smaller than the size of the package mounting area by that much, the maximum standard size of the package becomes strict, and the actual However, even a package that should be a non-defective product that does not cause any problem in mounting is treated as a defective product, and the yield is low.

The present invention has been made in view of the above circumstances, and has as its main object to provide a method of manufacturing a package capable of relaxing the maximum size standard of the package and improving the yield. The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0007]

The outline of a typical invention among the inventions disclosed in the present application is as follows. That is, the method of manufacturing the package of the present invention
First, the multiple electrodes of the semiconductor package are imaged
Recognizing and determining their positions, the position information of the plurality of electrodes
The center of the electrode arrangement pattern and the
A coordinate system with the center point as the origin is obtained, and the half point is calculated from the center point.
Measure the dimensions to each side of the periphery of the conductor package, and
The dimensions of the semiconductor package are set in advance.
It is determined whether or not the allowable dimensions of the semiconductor package are satisfied, and the semiconductor package is determined.
The quality of the cage was determined .

[0008]

According to the above means, since the center point of the arrangement pattern of the plurality of electrodes provided on the package is used as a reference, the distance from the center point to each side of the peripheral side of the package is determined by the mounting board. If the distance is equal to or less than the distance from the center point of the package mounting area to each side of the area, the package will not protrude from the package mounting area when mounted. Therefore, the maximum dimension of the package can be defined by the distance from the center point of the package mounting area to each side of the area, and the maximum dimension specification of the package can be relaxed.

[0009]

1 to 5 show one embodiment of a method of manufacturing a package according to the present invention, which will be described below. Among them, FIG. 1 is a block diagram showing an outline of a package shape inspection device, FIG. 2 is a schematic configuration diagram of a package shape inspection device, and FIG. 3 is a diagram showing a center point of an arrangement pattern of electrodes provided on the package. FIG. 4 is a flowchart showing a procedure for moving the package to a reference position for measurement, FIG. 4 is an explanatory diagram for explaining a package angle correcting method, and FIG. 5 is an explanatory diagram for explaining a package dimension measuring method.

In this package shape inspection method, when measuring the dimensions of a rectangular package enclosing a semiconductor chip, for example, a package 8 as shown in FIG. Among them, the positions of the appropriate electrodes (for example, the four corner electrodes A, B, C, and D) are determined,
From these positions, a virtual XY axis (line segment X ′) in an electrode arrangement pattern (hereinafter simply referred to as “arrangement pattern”)
X ′, Y′Y ′) and the center point J, and the distance to each side of the peripheral side of the package 8 is measured based on the center point J. Hereinafter, a package shape inspection device (hereinafter, referred to as “package inspection device”) used for shape inspection according to the present method
It is simply referred to as “shape inspection device”. The features of the present method and the present apparatus will be clarified by giving an example). As shown in FIGS. 1 and 2, the shape inspection apparatus 1 includes a position correction stage 2 (so-called X
Y stage), an angle correction stage 3 that rotates the package by rotating itself, a recognition device 4 such as a camera that recognizes the electrodes of the package, a measurement device 5 that measures the dimensions of the package, A control device 6 such as a computer connected to each stage and each device and controlling them is provided. The control device 6 is also connected to a transfer device 7 which comprises a horizontally movable XY robot 70 and a vertically movable Z-axis hand 71 for transferring the package.

The control device 6 includes a positioning means 60 for setting the initial position of the package, a recognition means 61 for recognizing the electrodes, a coordinate conversion means 62 for representing the recognized positions of the electrodes by coordinates, and A center point calculating means 63 for obtaining the center point of the set pattern, a rotation calculating means 65 and a movement calculating means 66, comprising a position correcting means 64 for correcting the position of the package, and a measuring means 67 for measuring dimensions. Have been.

With reference to FIG. 1, the respective means will be described along with the movement of each stage and each device along the flow of inspection. First, when an operation start signal or the like is input to the positioning means 60 by turning on an operation switch (not shown) of the shape inspection device 1, the positioning of the package 8 is performed. Specifically, the transport device 7 and the position correction stage 2 are respectively operated based on the transport command and the positioning command output from the positioning unit 60, and the package 8
Is moved right below the recognition device 4. Here, the package 8 is vacuum-adsorbed to the angle correction stage 3 with the side on which the electrodes are provided (back side) facing upward.

When the position correction stage 2 stops, a movement end signal is inputted from the positioning means 60 to the recognizing means 61, and a reference electrode (hereinafter, referred to as an electrode at four corners, for example).
Called "recognition points". ) Is performed. Specifically, the recognition device 4 operated and controlled based on the recognition device control command output from the recognition device 61 returns an image signal obtained by performing signal processing on the image of the electrode to the recognition device 61. On the other hand, in order to sequentially detect the recognition points based on this video signal, the position correction stage 2 is moved based on the movement command output from the recognition means 61, and each recognition point is recognized one after another. Since a method of recognizing electrodes by a camera is well known, a detailed description is omitted.

After all the recognition points have been recognized, the data of each recognition point is input to the coordinate conversion means 62, and the coordinates at the center of each recognition point are calculated from the amount of movement of the position correction stage 2 and the like. The coordinate data is input to the center point calculation means 63, and the coordinates of the virtual XY axes and the center point of the arrangement pattern are calculated and obtained.

When the coordinates of the center point of these arrangement patterns and the data of the virtual XY axes are input to the position correcting means 64,
The package 8 is moved to a reference position serving as a measurement reference. The position correction means 64 is divided into a rotation calculation means 65 for rotating the package 8 and a movement calculation means 66 for moving the package 8 in parallel, and the angle correction stage 3 is controlled based on the rotation command output from the rotation calculation means 65. While being rotated, the position correction stage 2 is moved based on the movement command output from the movement calculating means 66.

When the position correction stage 2 and the angle correction stage 3 are stopped, a correction end signal is input from the position correction means 64 to the measurement means 67, and measurement is performed in the measurement device 5. At this time, the position correction stage 2 is moved based on the movement command output from the measuring means 67, and the package 8 is positioned at the measuring position of the measuring device 5. Thereafter, the measurement is started based on the measurement command output from the measuring means 67.

Next, an example of the center point calculating means 63 and the position correcting means 64, which are one of the features of the present invention, will be described with reference to FIGS. Here, four corner electrodes A,
Let B, C and D be recognition points. In FIG. 4, the arrangement pattern is on the left side, and the X axis (line segment XX) and the Y axis (line segment Y) at the reference position K of the position correction stage 2 are on the right side.
Y) are shown respectively. First, a virtual rectangle (indicated by a dashed line in FIG. 4) having each recognition point as a vertex is set based on the input coordinate data of each recognition point.
The coordinates of the midpoints E, F, G, and H on each side are calculated and obtained (step S630). A line that connects the midpoints of the opposing sides of the midpoints E, F, G, and H (the midpoints E and G, the midpoints F and H), and becomes the virtual XY axis of the arrangement pattern. The minutes EG and FH are calculated and obtained (step S631).
For example, the line segment EG and the line segment FH are the virtual Y axis and the virtual X axis in the arrangement pattern, respectively. Then, the line segment EG
The coordinates of the intersection J ′ between the line and the line segment FH are calculated and obtained (step S632). This intersection point J 'is the center point J of the arrangement pattern.

Next, the X-axis and Y-axis data of the position correction stage 2 set in advance on the position correction stage 2 are inputted, and the angle -θ formed by the line Y'Y 'with respect to the line YY is input.
₁ (hereinafter, the clockwise positive direction.) Than the average of the angle - [theta] ₂ between the line segment X'X for line XX ', the angle correction stage 3 (i.e. package 8) calculates the rotation angle of the It is determined (step S650). In this case, the rotation angle is (θ ₁ + θ ₂ ) / 2. Based on this rotation angle, the angle correction stage 3 is rotated to change the angle of the package 8 by (θ ₁ + θ ₂ ) / 2 (step S651).

After step S632, the data of the coordinates of the reference position K is input, and the data is input to step S6.
Based on a comparison with the data of the coordinates of the center point J obtained in step 32, the amount of movement of the position correction stage 2 (that is, the package 8) that can make the center point J coincide with the reference position K is calculated (step S660). . Based on this movement amount, the position correction stage 2 is moved to position the package 8 at the reference position K (step S661). Steps S650 to S651 and steps S660 to S661 may be performed simultaneously, or one of them may be performed first. Thereafter, the process proceeds to the measuring means 67.

Next, a measuring method in the measuring device 5 will be described with reference to FIGS. For example, the measuring device 5 includes an irradiation unit 50, a light receiving unit 51, and a reference edge 52. The laser beam emitted from the irradiation unit 50 to the package 8 is received by the light receiving unit 51. And the length b of the gap is determined. In this state, the position correction stage 2 is moved in parallel with the X-axis and the Y-axis, which are perpendicular to the plane of the drawing of FIG. 5, so that the laser beam is irradiated over the entire area of the side of the package 8 to be measured. Move slowly.

The distance a from the tip of the reference edge 52 to the center point J of the arrangement pattern is kept constant for packages of the same standard. At this time, the dimension at the measurement point is given by ab. If the minimum value of b on the side to be measured is b ', the maximum value of the dimension on that side is given by ab'. The above measurement is performed for four sides of the package 8.

As described above in detail, according to the above embodiment, the distance from the center point J to each side of the package depends on the center point J of the arrangement pattern. If the distance is equal to or less than the distance from the center point of the area to each side of the area, the package will not protrude from the package mounting area when mounted. Therefore, the maximum dimension of the package can be defined by the distance from the center point of the package mounting area to each side of the area. The standard can be relaxed as compared with the maximum size standard of the conventional package which has been specified small, and the yield of products can be improved.

The invention made by the present inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the invention. Needless to say. For example, in the above embodiment, the electrodes A, B, C, and D at the four corners are used as recognition points. However, the present invention is not limited to this. For example, a virtual square having the electrodes A, B, C, and D as vertices is used. The electrode at any position may be used as the recognition point as long as the center point of the arrangement pattern can be determined, for example, by using the electrodes located near the midpoints E, F, G, and H on each side as the recognition points. The number of recognition points is not limited to four, but may be two, three, five or more. The center point can be obtained more accurately as the number of recognition points increases. Further, the calculation for obtaining the virtual XY axes and the center point of the arrangement pattern from the data of the recognition points is not limited to the calculation in the above embodiment as long as the virtual XY axes and the center point can be obtained. Furthermore,
In the above embodiment, the package 8 is temporarily moved to the reference position K.
Although it has been moved to the measurement position after being stopped by the above, the reference position may be made to coincide with the measurement position. Further, the measuring device 5 and the measuring method thereof are not limited to the devices and methods of the above embodiments.

In the above description, the case where the invention made by the present inventor is mainly applied to the inspection of the shape of a package, which is the field of application as the background, has been described. However, the present invention is not limited to this, and is not limited thereto. It can be used when measuring the outer dimensions of an object.

[0025]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows. That is, when measuring the dimensions of a rectangular package, the center point of the arrangement pattern of a plurality of electrodes provided on the package is used as a reference. Since the maximum dimension of the package can be specified by the distance from the point to each side of the area, the maximum size of a possible manufacturing error is anticipated and the size is specified to be one size smaller than the size of the package mounting area. The standard can be relaxed as compared with the maximum size standard of the conventional package. Therefore, the product yield can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically illustrating a package shape inspection apparatus according to an embodiment.

FIG. 2 is a schematic configuration diagram of a package shape inspection device.

FIG. 3 is a flowchart showing a procedure for obtaining a center point of an arrangement pattern of electrodes provided on a package and moving the package to a reference position for measurement.

FIG. 4 is an explanatory diagram illustrating a method of correcting an angle of a package.

FIG. 5 is an explanatory view illustrating a method of measuring the dimensions of a package.

[Explanation of symbols]

A, B, C, D Electrodes at four corners (recognition points) E, F, G, H Middle points of each side of virtual rectangle J Center point of arrangement pattern J 'Intersection of line segments EG, FH (virtual XY axes) K Reference position EG, FH A line segment connecting the midpoints of opposing sides (virtual X
XX X-axis at reference position K YY Y-axis at reference position K −θ ₁ Angle between line Y′Y ′ and line YY −θ ₂ Angle between line X′X ′ and line XX Angle 1 Shape inspection device 2 Position correction stage 3 Angle correction stage 4 Recognition device 5 Measuring device 6 Control device 8 Package 63 Center point calculation means 65 Rotation calculation means 66 Movement calculation means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-57-113356 (JP, A) JP-A-4-330756 (JP, A) JP-A-4-307950 (JP, A) JP-A-63-113 247605 (JP, A) JP-A-4-206846 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/66

Claims (1)

(57) [Claims] 1. A plurality of electrodes of a semiconductor package are image-recognized to determine their positions, and based on the position information of the plurality of electrodes, a center point of an electrode arrangement pattern and a coordinate system having the center point as an origin. Measuring a dimension from the center point to each side of a peripheral portion of the semiconductor package, determining whether each dimension satisfies a preset allowable dimension of the semiconductor package, A method of manufacturing a package, comprising determining the quality of a semiconductor package.