JP4277428B2 - Bonding paste coating apparatus and coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and a method for applying bonding paste, capable of superior operability and obtaining satisfactory application quality. SOLUTION: In this bonding paste applying method for plotting and applying the bonding paste, while discharging the bonding paste from an applying nozzle, a plotting pattern used for the control of a moving means for moving the applying nozzle is generated by a plotting pattern calculation part 44, based on the size of an object chip and a basic shape pattern for specifying the plotting shape of the plotting pattern stored in a storage part 37 beforehand and the speed pattern of the moving means is calculated by a speed pattern calculation part 45, based on the generated plotting pattern and is mode to be stored in a speed pattern storage part 46. Thus, an appropriate plotting pattern is set, corresponding to the kind and size of the chip with superior operability and the appropriate paste is applied efficiently.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bonding paste coating apparatus and a coating method for coating a bonding paste for chip bonding on a substrate.
[0002]
[Prior art]
In a die bonding process for manufacturing a semiconductor device, a bonding paste for bonding a semiconductor chip to a substrate such as a lead frame is applied. The bonding paste is applied by guiding the bonding paste discharged from the dispenser to the application nozzle and applying it in the application area of the substrate. As one of the coating methods, drawing coating is known in which coating is performed by discharging a paste while moving a coating nozzle in a coating area.
[0003]
[Problems to be solved by the invention]
In this drawing application, the required paste application amount and application form differ depending on the shape and size of the chip to be bonded, so the application conditions such as the drawing shape at the time of drawing and the speed pattern when moving the application nozzle depend on the chip. Need to be set. However, in the conventional bonding paste coating apparatus, setting of the coating conditions for performing the above-described drawing coating requires troublesome operations such as complicated data input each time, and the operability is poor and appropriate settings are performed. If not, there was a problem that good coating quality could not be obtained.
[0004]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a bonding paste coating apparatus and a coating method that are excellent in operability and can obtain good coating quality.
[0005]
[Means for Solving the Problems]
The bonding paste coating apparatus according to claim 1 is a bonding paste coating apparatus that draws and applies a bonding paste by moving the coating nozzle while discharging the bonding paste from the coating nozzle at a chip mounting position of the substrate. An application nozzle that discharges paste from the mouth and applies it to the substrate, a moving means that moves the application nozzle relative to the substrate, a chip size storage unit that stores the chip size, and a basic shape pattern of the drawing pattern A basic shape pattern storage unit for storing shape data; an input device for inputting operation commands and numerical data; and a chip size storage unit based on a chip type and a basic shape pattern type input from the input device; A basic shape pattern of a drawing pattern from the basic shape pattern storage unit. Read shape data and the chip size of the emissions, the drawing pattern generation means for generating a drawing pattern based on the read shape data and chip size, sets a speed pattern of said moving means based on the generated drawing pattern Speed pattern setting means and drive means for driving the moving means based on the set speed pattern are provided.
[0006]
The method of coating according to claim 2, wherein the bonding paste is a method of applying a bonding paste for drawing applying a bonding paste by moving the coating nozzle while discharging the bonding paste from the coating nozzles in the chip mounting position of the substrate, the input The shape data of the basic shape pattern of the drawing pattern and the size of the chip are read from the chip size storage unit and the basic shape pattern storage unit based on the type of chip and the type of the basic shape pattern input from the apparatus. the drawing pattern which is used to control the moving means for moving the coating nozzle forms live based on size, and set the speed pattern of the moving means based on the generated drawing pattern, the coating on the basis of the speed pattern While moving the nozzle And so as to discharge the loading paste.
[0007]
According to the present invention, a drawing pattern used for controlling the moving means for moving the coating nozzle is generated based on the basic shape pattern of the drawing pattern and the chip size, and the speed of the moving means is generated based on the generated drawing pattern. By setting the pattern, an appropriate drawing pattern can be set with good operability according to the type and size of the chip, and appropriate paste application can be performed efficiently.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. 1 is a perspective view of a die bonding apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of a control system of the die bonding apparatus according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. FIG. 4 is an explanatory diagram showing a basic shape pattern of a drawing pattern of a die bonding apparatus according to an embodiment of the present invention, and FIG. 5 is a diagram illustrating the present invention. FIG. 6 is a graph showing a drawing pattern speed pattern of the die bonding apparatus according to the embodiment of the present invention, and FIG. FIG. 7B is a cross-sectional view of the coating area of the die bonding apparatus according to one embodiment of the present invention.
[0009]
First, the structure of the die bonding apparatus will be described with reference to FIG. In FIG. 1, a wafer sheet 2 is held on a chip supply unit 1 by a holding table (not shown). The wafer sheet 2 has a large number of semiconductor chips 3 attached thereto. A conveyance path 5 is disposed on the side of the chip supply unit 1. The conveyance path 5 conveys the lead frame 6 and positions the lead frame 6 at the paste application position and the bonding position. A bonding head 4 is disposed above the chip supply unit 1, and the bonding head 4 moves horizontally and moves up and down by a moving mechanism (not shown).
[0010]
A paste application unit 9 is disposed on the side of the conveyance path 5. The paste application unit 9 is configured by mounting a syringe 15 of a dispenser provided with an application nozzle 15a on a moving table 10. The moving table 10 is configured by stacking an X-axis table 12 on a Y-axis table 11 and further connecting a Z-axis table 14 in the vertical direction via an L-shaped bracket 13 thereon. The Y-axis table 11, the X-axis table 12, and the Z-axis table 14 include a Y-axis motor 11a, an X-axis motor 12a, and a Z-axis motor 14a, respectively.
[0011]
The syringe 15 moves horizontally and vertically on the lead frame 6 by driving the X-axis motor 12a, the Y-axis motor 11a, and the Z-axis motor 14a. A paste 7 for adhering the chip 3 to the lead frame 6 is stored inside the syringe 15, and the valve 15 b (see FIG. 2) that opens and closes the application nozzle 15 a with the air pressure applied in the syringe 15 is opened. By doing so, the paste is discharged from the discharge port of the coating nozzle 15a.
[0012]
The chip bonding part 6a to which the chip 3 on the upper surface of the lead frame 6 is bonded is an application area 6a to which the paste is applied. The discharge port of the application nozzle 15a is positioned in the application area 6a and the paste is discharged from the application nozzle 15a. By moving the application nozzle 15a while moving, the paste 7 is applied in an X-shaped application pattern in the application area 6a set at the chip mounting position on the surface of the lead frame 6. The air pressure applying means for applying air pressure to the syringe 15, the application nozzle 15a and the syringe 15 is a paste discharge means, and the moving table 10 is a moving means for moving the discharge port of the application nozzle 15a.
[0013]
After applying the paste, the lead frame 6 is sent to the bonding position 8 on the conveyance path 5 and positioned. The chip 3 picked up from the chip supply unit 1 by the nozzle 4a of the bonding head 4 is bonded onto the paste 7 applied in the application area 6a.
[0014]
Next, the control system of the die bonding apparatus will be described with reference to FIG. In FIG. 2, the air supplied from the air source 20 is supplied into the syringe 15 through the regulator 21. The regulator 21 can remotely control the set pressure, and the pressure of the air supplied to the syringe 15 is adjusted by controlling the regulator 21 by the control unit 36, and the discharge amount of the paste discharged from the application nozzle 15a Can be controlled. The discharge control valve drive unit 31 drives a valve 15b that opens and closes the coating nozzle 15a. By controlling the discharge control valve driving unit 31 by the control unit 36, it is possible to intermittently discharge the paste from the coating nozzle 15a. Instead of controlling the set pressure of the regulator 21 by the control unit 36, the pressure may be set manually to obtain a required discharge amount.
[0015]
The X-axis motor drive unit 34, the Y-axis motor drive unit 33, and the Z-axis motor drive unit 32 drive the X-axis motor 12a, the Y-axis motor 11a, and the Z-axis motor 14a of the moving table 10, respectively. The operation of the moving table 10 is controlled by controlling the X-axis motor drive unit 34, the Y-axis motor drive unit 33, and the Z-axis motor drive unit 32 by the control unit 36 which is a control means.
[0016]
The storage unit 37 stores data on the application operation of the application nozzle 15a, that is, data such as the application start point and application end point set in the application area, the position of the nozzle passage point during the application operation, and the application nozzle 15a. Data such as a moving speed pattern and a discharge amount of paste is stored. The application area is controlled by controlling the movement operation of the application nozzle 15a driven by the movement table 10 by the control unit 36 and the discharge operation of the paste from the application nozzle 15a of the syringe 15 based on the data stored in the storage unit 37. The paste can be applied in a predetermined drawing pattern in 6a.
[0017]
The bonding head driving unit 35 is controlled by the control unit 36 to drive the bonding head 4. The operation / input unit 38 is an input device such as a keyboard and a mouse, and inputs operation commands and numerical data. The display unit 39 is a monitor device and displays a guidance screen at the time of input.
[0018]
Next, the processing function of the paste application processing of the die bonding apparatus will be described with reference to FIG. 3 correspond to the storage unit 36 shown in FIG. 2, and among the elements shown in FIG. 3, the input processing unit 40, the display processing unit 41, the drawing pattern calculation unit 44, The speed pattern calculation unit 45, the motion trajectory calculation unit 47, and the drawing processing unit 48 indicate processing by the control unit 36 shown in FIG.
[0019]
First, each unit constituting the storage unit 37 will be described. The chip size storage unit 42 stores chip size to be bonded, that is, data on the width and length of the chip 3. The basic shape pattern storage unit 43 is a basic shape pattern of a drawing pattern, that is, data for specifying the type of drawing shape such as a central dot shape, a cross shape, an asterisk shape, and a snow star shape, and a chip of a line element constituting each basic shape Stores numerical data such as ratio to size.
[0020]
Here, the drawing pattern will be described. In die bonding, the amount of paste applied required for bonding varies depending on the type and size of the chip. Since the bonding area increases as the chip size increases, the required paste application amount also increases. Furthermore, depending on the type of chip, it is required to set the coating density (paste coating amount per area) appropriately.
[0021]
When the paste discharge amount from the nozzle is constant, the paste application amount is proportional to the application length, and therefore the paste application amount may be considered to be approximately proportional to the application line length constituting the drawing pattern. Since the coating line length per area differs depending on the degree of complexity of the drawing pattern, it is necessary to set an appropriate drawing pattern according to the coating density given a desired paste application density. . In the present embodiment, the drawing pattern is set by combining the basic shape pattern of the drawing pattern and the chip size. In other words, the chip type is specified, the size is given, and the basic shape pattern is specified, so that the specific drawing shape and drawing length are determined, and the drawing pattern that gives the required coating amount with an appropriate coating density Is required.
[0022]
Here, examples of basic shape patterns are shown below. FIG. 4 (a) shows an example of a basic shape pattern for a rectangular chip in order from the simplest pattern, and a pattern (center point) for simply applying the paste 7 to the center point O of the application area. Pattern), a drawing pattern (cross-shaped pattern with a center dot) obtained by combining the cross-shaped application lines L1 and L2 in the diagonal direction, and a drawing pattern (cross-shaped pattern with a center point) combined with the vertical and horizontal application lines L3 and L4 An asterisk pattern with a center dot), and a drawing pattern (snow star pattern) in which a key-shaped coating line L5 is further added to the tip of the cross-shaped coating lines L3 and L4.
[0023]
FIG. 4B shows shape data of a cross-shaped pattern with a center dot among the patterns. These shape data are given in the form of relative ratios to the chip sizes X and Y, that is, as non-dimensionalized numerical data. For example, dimensionless numbers A, B, and D are given as data indicating the distances AX and BY between the end points of the cross-shaped coating line and the diameter DX of the coating point applied to the center. Then, by combining these numerical data and data X, Y indicating the size of the chip, the actual position and size of the coating line are specified.
[0024]
That is, by combining these basic shape patterns and the chip size, the specific dimension of each coating line length is specified, and the drawing pattern is determined. The dimensionless number indicating the relative ratio of the line elements constituting each drawing pattern can be changed on the screen by inputting a numerical value, and more various drawing patterns can be set according to the target. It can be done. By preparing such a basic shape pattern in advance, not only the total coating amount but also the coating density can be arbitrarily selected, and there is an advantage that an optimum drawing pattern according to the target chip can be selected. is there.
[0025]
The drawing pattern calculation unit 44 calculates a drawing pattern based on the chip size stored in the chip size storage unit 42 and the chip size and basic shape pattern data stored in the basic shape pattern storage unit 43. That is, the actual drawing shape is calculated by designating the size of the target chip and the type of drawing pattern. Therefore, the drawing pattern calculation unit 44 is a drawing pattern generation unit that generates a drawing pattern based on the basic shape pattern of the drawing pattern and the size of the chip.
[0026]
In the generation of the drawing pattern, a trajectory process (for example, setting of an R-shaped trajectory at the turn-back portion) is also performed for detailed portions such as a turn-back portion and a corner portion in the drawing trajectory. By processing the data of the drawing pattern by the display processing unit 41, the drawing shape can be confirmed on the monitor of the display unit 39.
[0027]
The speed pattern calculation unit 45 calculates a speed pattern for moving the application nozzle 15a based on the calculated drawing pattern for each XY axis component constituting the movement trajectory. The speed pattern storage unit 46 stores the speed pattern calculated by the speed pattern calculation unit 45. The speed pattern calculation unit 45 and the speed pattern storage unit 46 serve as a speed pattern setting unit that sets a speed pattern.
[0028]
By reading the stored speed pattern data and calculating the trajectory by the motion trajectory calculation unit 47, trajectory data indicating the trajectory during the actual motion can be obtained. By processing the locus data by the display processing unit 41, a locus similar to the locus of the actual application nozzle can be displayed on the display unit 39.
[0029]
The drawing processing unit 48 drives the X-axis motor driving unit 34, the Y-axis motor driving unit 33, the Z-axis motor driving unit 32, and the discharge control valve driving unit 31 in synchronization with each other to move the coating nozzle 15a, and also applies the coating nozzle. A process for performing drawing application is performed by discharging the paste 7 from 15a.
[0030]
The X-axis motor drive unit 34, the Y-axis motor drive unit 33, and the Z-axis motor drive unit 32 are an X-axis component speed pattern, a Y-axis component speed pattern, and a Z-axis direction speed stored in the speed pattern storage unit 46. Based on the pattern, the X-axis motor 12a, the Y-axis motor 11a, and the Z-axis motor 14a are driven. In the present embodiment, the X-axis motor driving unit 34, the Y-axis motor driving unit 33, and the Z-axis motor driving unit 32 constitute a driving unit that drives the moving unit based on the set speed pattern.
[0031]
The input processing unit 40 processes an operation input signal input from the operation / input unit 38, outputs a control command to each unit, and writes data to the storage unit 37. The display processing unit 41 processes the data stored in the storage unit 37 and causes the display unit 39 to display various guidance screens.
[0032]
Next, the drawing pattern determination process will be described with reference to FIG. When determining the drawing pattern, the type of the target chip and the type of the basic shape pattern to be selected are input from the operation / input unit 38 (ST1). Thereby, the size of the chip is read from the chip size storage unit 42, and the shape data of the basic shape pattern, that is, the numerical data indicating the relative position of the coating line constituting the drawing pattern is read from the basic shape pattern storage unit 43. (ST2). Here, as shown in FIG. 4, an example is shown in which side sizes X and Y of a rectangular chip that is a target chip are given, and the above-mentioned center-shaped cross-shaped pattern is selected as a basic shape pattern.
[0033]
Next, the drawing pattern calculation unit 44 generates a drawing pattern by calculation based on the shape data of the basic shape pattern and the chip size (ST3). Here, a specific dimension for specifying the position of each coating line is obtained, and thereby the outline of the drawing pattern is specified. The drawing pattern created by calculation can also be displayed on the monitor of the display unit 39 at this time. When it is necessary to partially correct the created drawing pattern, the relative position and length ratio between the coating lines can be corrected by inputting data on the display screen.
[0034]
Next, a speed pattern is created and stored by the speed pattern calculation unit 45 based on the selected drawing pattern (ST4). As a result, a specific speed pattern is created for each axis of the drive axis that moves the application nozzle 15a, taking into account the acceleration / deceleration conditions during actual axis driving. FIG. 6 shows the speed pattern set in the drawing pattern determination process. In the drawing pattern described above, the center point O is set as the application start point and the application end point, and the drawing point is applied with a single stroke after passing through the passing points A, B, C, and D on the application line in the middle of the drawing.
[0035]
At the time of this drawing application, the application nozzle 15a moves in the order of O-A-C-O-B-D-O. At this time, the X and Y movement axes (X-axis motor 12a and Y-axis motor 11a) have a speed pattern as shown in FIG. 6, that is, between each passing point from the coating start point O to the coating end point O. Thus, it is driven based on a speed pattern in which the trapezoidal acceleration / deceleration is repeated.
[0036]
Further, the Z-axis that moves the coating nozzle 15a up and down performs a lowering operation only at the start of coating and a lifting operation only at the end of coating. Immediately before this rise, as shown in FIG. 7B, dot application is performed in which the paste 7 is discharged while the application nozzle 15a is stopped at the center point O. By adjusting the coating amount at the center point O, the entire coating amount is adjusted.
[0037]
It is also possible to confirm the locus by displaying the motion locus calculated based on the created speed pattern on the monitor of the display unit 39. If there is no defect in the displayed trajectory, a speed pattern created based on the drawing pattern is stored as actual work data for application work. Thus, the drawing pattern determination process is completed.
[0038]
As described above, in the present invention, an appropriate drawing pattern corresponding to this chip can be generated simply by specifying the chip size of the chip to be bonded and the type of the desired drawing shape (basic shape pattern). The selected speed pattern is automatically set. Thereby, it is not necessary to set drawing data each time the chip type or size changes, and it is possible to ensure good bonding quality by always performing appropriate paste application with good operability.
[0039]
【The invention's effect】
According to the present invention, a drawing pattern used for controlling the moving means for moving the coating nozzle is generated according to the basic shape pattern of the drawing pattern and the size of the chip, and the speed of the moving means is generated based on the generated drawing pattern. Since the pattern is set, an appropriate drawing pattern can be set with good operability according to the type and size of the chip, and appropriate paste application can be performed efficiently.
[Brief description of the drawings]
FIG. 1 is a perspective view of a die bonding apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram showing a configuration of a control system of the die bonding apparatus according to an embodiment of the present invention. FIG. 4 is a functional block diagram showing the processing function of paste application processing of the die bonding apparatus of the embodiment. FIG. 4 is an explanatory view showing the basic shape pattern of the drawing pattern of the die bonding apparatus of the embodiment of the invention. FIG. 6 is a flow chart of a drawing pattern setting process of the die bonding apparatus according to the embodiment of the invention. FIG. 6 is a graph showing a speed pattern of the drawing pattern of the die bonding apparatus according to the embodiment of the invention. Plan view of coating area of die bonding apparatus according to one embodiment of the present invention (b) Cross section of coating area of die bonding apparatus according to one embodiment of the present invention
3 Chip 6 Lead frame 6a Application area 7 Paste 10 Moving table 15a Application nozzle 42 Chip size storage unit 43 Basic shape pattern storage unit 44 Drawing pattern calculation unit 45 Speed pattern calculation unit 46 Speed pattern storage unit

Claims (2)

A bonding paste application device that draws and applies a bonding paste by moving the application nozzle while discharging the bonding paste from the application nozzle at a chip mounting position on the substrate, and applies the paste to the substrate by discharging the paste from the application port. A nozzle, a moving means for moving the coating nozzle relative to the substrate, a chip size storage unit that stores a chip size, a basic shape pattern storage unit that stores basic shape pattern data of a drawing pattern, and an operation An input device for inputting commands and numerical data, and a basic shape pattern of a drawing pattern from the chip size storage unit and the basic shape pattern storage unit based on the type of chip and the type of basic shape pattern input from the input device Read data and chip size A drawing pattern generation means for generating a drawing pattern based on the data and the chip size, and speed pattern setting means for setting a speed pattern of said moving means based on the generated drawing pattern, based on the speed pattern set A bonding paste coating apparatus comprising driving means for driving the moving means. A bonding paste application method in which a bonding paste is drawn and applied by moving the application nozzle while discharging the bonding paste from the application nozzle at the chip mounting position on the substrate. The type of chip and the basic shape pattern input from the input device Control of moving means for reading the basic shape pattern data of the drawing pattern and the chip size from the chip size storage unit and the basic shape pattern storage unit from the type, and moving the application nozzle based on the read data and the chip size the drawing pattern form raw used in to set the speed pattern of the moving means based on the generated drawing pattern, and characterized in that for discharging the bonding paste while moving the coating nozzle on the basis of the speed pattern Bonding Paste method of applying.

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