JP3984824B2 - Liquid material discharge device and resin sealing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid material discharge device that discharges a predetermined amount of a liquid material for compression molding onto a workpiece, and a resin sealing device that supplies a liquid resin to a molded product using the liquid material discharge device and performs compression molding.
[0002]
[Prior art]
Various types of resin sealing devices for resin-sealing semiconductor packages have been developed and put into practical use. For example, when resin-sealing a single-sided mold type semiconductor package such as QFN (Quad, Flat, Non-leaded) or SON (Small, Outline, Non-leaded), etc., A prescribed amount of liquid resin is applied to a semiconductor wafer in which semiconductor chips are mounted in a matrix on a silicon wafer. Specifically, resin sealing has been performed by applying a liquid resin by potting or by spin-coating by flowing the liquid resin down. In the case of a small and thin semiconductor package, in order to achieve uniform molding quality, it is easy to cure by heating, and it is encapsulated by accurately measuring the amount of resin without moving the sealing resin as much as possible. Is desired.
[0003]
Therefore, there is a method in which a solid resin (resin tablet), a powder resin, a liquid resin, or the like is supplied onto a molded product such as a substrate or a wafer and clamped between an upper mold and a lower mold to perform compression molding. According to this compression molding, the amount of resin required for the molded product can be measured and sealed, so there is no waste in the sealing resin and the range in which the resin flows is limited. In this case, uniform molding is possible.
[0004]
[Problems to be solved by the invention]
However, since the solid resin (resin tablet) is solid, there is a problem that it is easy to cause a wire flow (wire sweep) of a wire provided on a substrate or a wafer, and it is difficult to add a resin amount.
In an actual manufacturing process, a predetermined number of semiconductor chips may not be mounted on a substrate or a silicon wafer that is a molded product. In this state, if a prescribed amount of liquid resin is applied to the product to be molded, the sealing resin for the insufficient volume of the semiconductor chip may be insufficient, and the thickness of the entire package may become thin, resulting in molding defects. there were. Further, when the number of chipped portions of the semiconductor chip increases, there is a possibility that a semiconductor chip portion that is not completely resin-sealed may occur.
In addition, the compression molding does not have a portion (unnecessary resin portion) that causes play of the resin amount as in the case of transfer molding, so that a high liquid resin application accuracy (resin amount accuracy) is required. In particular, it is liquid due to factors such as the wear of the nozzle or seal of a dispenser (discharge device) that discharges liquid resin, the ambient temperature at which the resin is sealed, the air mixed in the liquid resin, and the viscosity of the liquid material itself. Resin discharge amount tends to vary.
[0005]
The object of the present invention is to solve the above-mentioned problems of the prior art, and to improve the molding quality by using a liquid material discharge device capable of applying an optimum amount of compression molding liquid material for each work with high accuracy. An object of the present invention is to provide an improved resin sealing device.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention has the following configuration.
That is, in a liquid material discharge device that discharges a predetermined amount of a liquid material for compression molding to a workpiece, A chuck that transports the workpiece sent from the workpiece supply unit to the discharge position on the support rail, and the workpiece that has been transferred to the discharge position. work What Discharge liquid material while scanning in XYZ direction Do Discharge means; Liquid material was discharged Work weight The With weighing means to weigh And a control unit for controlling the discharge amount of the liquid material from the discharge means based on the measurement result of the measurement means With The measuring means has a measuring device body provided with a measurement mounting plate supported so as to be able to move up and down below the discharge position of the support rail, and the measurement mounting plate arranged in the gap between the support rails moves up and down. When the workpiece is received from the support rail and measured, the control unit adjusts the corrected discharge amount so that the difference between the discharge weight of the liquid material actually discharged from the measured workpiece weight and the target discharge weight falls within the allowable range. Calculate and instruct the discharge command of the corrected discharge amount to the next workpiece by the discharge means It is characterized by that.
In addition, the number of semiconductor chip defects in the workpiece Measured by weight measurement of workpiece, image processing performed by imaging workpiece, chip height measurement, or change in reflectance of light obtained by irradiating the workpiece with light Enhance the amount of liquid material corresponding to the semiconductor chip defect Liquid material is discharged from the discharge means. It is characterized by that.
Further, the weighing means measures the weight of the workpiece before and after the discharge of the liquid material, so that the variation in the discharge amount of the liquid material per work by the discharge means can be finely adjusted within an allowable tolerance range. Features.
In addition, mold clamping movement information of the mold and Pre-measured Based on the plate thickness information of the workpiece, the variation in the discharge amount of the liquid material per workpiece by the discharge means can be finely adjusted within an allowable tolerance range.
Further, the plate thickness of the workpiece is measured before resin sealing, and the amount of liquid material considering the variation in the plate thickness of the workpiece is discharged.
Further, the discharging means is characterized in that the central part of the work is applied so that the application height of the liquid material is higher than the peripheral part or the application amount is larger.
In addition, when applying the liquid material to the workpiece by the discharge means, Through the chuck It is characterized by applying while vibrating the workpiece.
Further, when the liquid material is applied to the workpiece by the discharge means, the liquid material is applied while being heated.
Further, the discharge means is a dispenser having a single nozzle or a multi-nozzle.
Further, the discharge means is a dispenser provided with a flat nozzle having a wide liquid material discharge port.
[0007]
The resin sealing device is characterized in that a liquid resin is supplied to a product to be molded using any one of the liquid material discharge devices described above and compression molding is performed.
In addition, a servo motor is provided as a drive source for opening and closing the mold, and the clamping movement information obtained by measuring the rotation amount of the servo motor when clamping the mold and Pre-measured The compression molding is performed by finely adjusting the liquid material discharge amount of the liquid material discharge device based on the plate thickness information of the workpiece.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a liquid material discharge device and a resin sealing device according to the present invention will be described in detail with reference to the accompanying drawings. In the present embodiment, a liquid material discharge device that discharges a liquid resin used in a compression molding method onto a workpiece and a resin sealing device including the liquid material discharge device will be described.
1 is a plan view of the liquid material discharge device, FIG. 2 is a front view of the liquid material discharge device of FIG. 1, FIGS. 3 to 5 are explanatory views of the liquid material discharge operation of the liquid material discharge device, and FIG. FIG. 7 is an explanatory diagram illustrating the application pattern of the liquid material on the workpiece, and FIGS. 8A, 8B, and 8C are explanatory diagrams illustrating the nozzle shape of the dispenser and the liquid material application method. 9 is a block explanatory view showing a liquid material discharge amount adjusting mechanism according to another example, FIG. 10 is a plan view of the resin sealing device, FIG. 11 is a front view of the resin sealing device in FIG. 10, and FIG. (B) is explanatory drawing of a workpiece | work, FIG. 13 (a) (b) is explanatory drawing which shows the application pattern of the liquid material which concerns on another example.
[0009]
First, a schematic configuration of the resin sealing device will be described with reference to FIGS.
10 and 11, reference numeral 1 denotes a workpiece supply unit that houses a plurality of workpieces that are molded on one side. In this embodiment, a substrate (film substrate, lead frame, resin substrate, etc.) 2 (see FIG. 12B) on which semiconductor chips are mounted in a matrix is accommodated in the magazine 3 as an example of a workpiece. A slit is formed on the cut-out side surface of the magazine 3 and is fed one by one from the lowermost substrate 2 by a cut-out plate (pusher) 5 operated by the actuator 4. As shown in FIG. 11, the magazine 3 is supported by the elevator mechanism 6 and accommodated in a stack, and is lowered by one pitch every time one substrate 2 is cut out so as to prepare for the next cutting out of the substrate 2. It has become. In addition to the substrate 2, the work to be molded on one side may be a silicon wafer 7 in which semiconductor chips shown in FIG. 12A and 12B, the grid-like lines formed on the substrate 2 and the silicon wafer 7 indicate one section of the package.
[0010]
Reference numeral 8 denotes a liquid material discharge device as an example of a resin supply unit, which quantitatively discharges and supplies the liquid material (liquid resin) to the work (substrate 2 and silicon wafer 7) supplied from the work supply unit 1. The front end side of the substrate 2 sent out from the magazine 3 by the cutting plate 5 is transferred to the support rail 9. The substrate 2 is transported to the discharge position P on the support rail 9 by moving the chuck 10 while being guided by the guide rail 11 provided in parallel to the support rail 9 while the tip of the substrate 2 is chucked by the chuck 10. Is done. Reference numeral 12 denotes a camera for picking up a workpiece, which is provided so that the substrate 2 can be picked up before the resin is supplied to check a defective portion of the semiconductor chip.
[0011]
Reference numeral 13 denotes a dispenser as an example of an ejection unit, and the dispenser 13 is provided so as to eject a liquid resin while scanning the substrate 2 in the XYZ directions. The liquid resin is fed from a storage tank (not shown) to the dispenser 13 via a tube or the like. The dispenser 13 scans the substrate 2 in the X, Y, and Z directions, and applies a predetermined amount of the liquid resin from the nozzle 13a to an arbitrary pattern. To discharge.
[0012]
Reference numeral 14 denotes a weight measuring device as an example of a weighing unit, which is provided so as to be able to measure the weight of the workpiece (substrate 2 and silicon wafer 7) and / or the amount of liquid resin discharged to the workpiece. The weight measuring device 14 is provided with a measurement mounting plate 14b on the measuring device main body 14a, and the measuring device main body 14a measures the weight by placing the substrate 2 on the measurement mounting plate 14b. It is supposed to be. The weight measuring device 14 is provided below the discharge position P of the support rail 9. The measurement mounting plate 14 b is formed by an elongated plate along the support rail 9 and is disposed in the gap between the support rails 9. The measuring apparatus main body 14a is placed on a measuring apparatus support base 15, and the measuring apparatus support base 15 is connected to an elevating cylinder 16 so as to be movable up and down.
[0013]
Reference numeral 17 denotes a compression molding apparatus as a resin sealing portion, which clamps the substrate 2 supplied with the liquid resin with a lower mold 18 and an upper mold 19 to perform compression molding. The substrate 2 on which the liquid resin is discharged by the liquid material discharge device 8 is transferred to the lower mold 18 that is held by the loader 20 and stands by at the take-out position Q. The lower mold 18 is movable between a clamp position R facing the upper mold 19 and an extraction position Q where the substrate 2 is delivered from the loader 20. A cavity (not shown) is formed in the upper mold 19, and a release film 21 is stretched on the parting surface.
[0014]
The release film 21 is a long film. The release film 21 is fed from a supply reel 22a by a film transport mechanism 22 and wound onto a take-up reel 22b through an upper die 19. The release film 21 has heat resistance that can withstand the heating temperature of the mold, and is easily peeled off from the upper mold surface. The release film 21 is a film material having flexibility and extensibility, such as PTFE, ETFE, PET, FEP, fluorine-impregnated glass cloth, polypropylene, polyvinylidin chloride and the like are preferably used. The release film 21 is stretched in close contact with the upper mold surface by sucking air from a suction hole (not shown) formed on the parting surface of the upper mold 19.
[0015]
Of the mold dies, the upper mold 19 is supported by the upper movable platen 23 a and can move up and down together with the film transport mechanism 22. The lower mold 18 is supported by the fixed platen 24. The lower movable platen 23 b is connected to the screw shaft 25 via a nut 26, and a pulley 27 is attached to the screw shaft 25. The upper and lower movable platens 23 a and 23 b are integrally connected by a movable tie bar 50. . A servo motor 28 is a drive source, and a pulley 29 is provided on the motor shaft. An endless timing belt 30 is stretched between the pulley 27 and the pulley 29. When the servo motor 28 is driven, the screw shaft 25 is rotated via the timing belt 30 spanned between the pulleys 27 and 29, and the vertically movable platens 23a and 23b are moved up or down.
[0016]
When the mold is opened after compression molding, the release film 21 is easily separated from the resin, so that the release film 21 is separated from the substrate 2 while being adsorbed by the upper mold 19, and the substrate 2 is moved to the lower mold 18 side. Remains. The substrate 2 is taken out by moving the lower die 18 from the clamp position R to the take-out position Q while being placed on the lower die 18. And it is hold | gripped by the unloader 31 standing by in the taking-out position Q, and is transferred to a molded article storage part.
[0017]
Reference numeral 32 denotes a molded product storage device as an example of a molded product storage unit. The molded product storage device 32 includes a moving table 33 that delivers the substrate 2 after compression molding, a pickup device 34 that sucks and holds the substrate 2 from the moving table 33 and rotates to align the orientation, and sucks and holds the pick-up device 34. A storage magazine 35 for storing the substrate 2 is provided.
[0018]
The substrate 2 placed on the lower mold 18 is transferred to the moving table 33 held by the unloader 31 and waiting at the receiving position U. The moving table 33 moves from the receiving position U to the storage position V while the substrate 2 is placed, and is sucked and held by the pickup device 34. The transfer table 33 moves from the storage position V to the receiving position U again when the substrate 2 is delivered. The pick-up device 34 stores the substrate 2 in the storage magazine 35 with the substrate 2 being sucked and held, for example, rotated 90 degrees and aligned.
[0019]
Next, a specific configuration of the liquid material discharge device 8 will be described with reference to FIGS. 1 and 2. The dispenser 13 is provided so that the liquid resin can be discharged while scanning the substrate 2 in the XYZ directions. In FIG. 1, the dispenser 13 is attached so as to be movable along the Z-axis moving arm 36 in the Z-axis direction. The Z-axis moving arm 36 is attached so as to be movable in the X-axis direction along the X-axis moving arm 37. The X-axis moving arm 37 is attached so as to be movable in the Y-axis direction along the Y-axis moving arm 38.
[0020]
The substrate 2 sent out from the workpiece supply unit 1 is sent out to the support rail 9 and the front end side of the substrate is chucked by the chuck 10. The chuck 10 is provided with an L-shaped claw portion 10b at the distal end portion of the arm portion 10a so as to be opened and closed. The claw portion 10b is opened and closed by an electromagnetic solenoid or the like. Further, the claw portion 10b may be provided with a vibrator for vibrating the substrate 2 when discharging the liquid resin as will be described later. The arm portion 10 a is supported by a guide rail 11 provided in parallel with the support rail 9, and a part thereof is fixed to an endless timing belt 39. The timing belt 39 is stretched between pulleys 40 and 41 provided on both ends of the guide rail 11, and is driven to rotate forward and backward by a servo motor 42. When the servo motor 42 is activated, the arm portion 10a linked to the timing belt 39 moves along the guide rail 11, and the substrate 2 chucked by the claw portion 10b is transported on the support rail 9 to the discharge position P.
[0021]
The weight measuring device 14 is disposed immediately below the discharge position P of the support rail 9. The weight measuring device 14 is placed on the measuring device support 15. The measuring device support 15 is connected to a cylinder rod of an elevating cylinder (air cylinder) 16 supported by a cylinder base 43. When the raising / lowering cylinder 16 is operated, the cylinder rod extends to move the measuring device support base 15 upward along the guide post 44, and the measurement mounting plate 14 b provided on the measuring device main body 14 a is attached to the support rail 9. By placing the substrate 2 when moving upward, the measuring device main body 14a measures the substrate weight.
[0022]
The weight measuring device 14 may measure the weight of the substrate 2 before and after discharging the liquid resin, or may measure the weight during discharge of the liquid resin to the substrate 2. Based on this measured value, the dispersion of the liquid material discharge amount per work by the dispenser 13 is suppressed within an allowable tolerance range. Incidentally, since the thickness of the package is as thin as about 0.8 mm, for example, the measurement of the liquid resin requires accuracy. Although it varies depending on the product, it is required to suppress the variation in the thickness of the package to a tolerance of ± 5% or less. In particular, in the work (substrate 2, silicon wafer 7) in which semiconductor chips are arranged in a matrix, there are cases where the chipped portions 2 a and 7 a (see FIGS. 12A and 12B) of the semiconductor chips exist. It is necessary to correct the discharge amount of the liquid resin discharged onto the work by measuring the number of semiconductor chips mounted on the work and comparing it with the number of semiconductor chips assumed to have no defective chip. That is, it is necessary to fill the space of the chip defect portion by increasing the discharge amount of the liquid resin.
[0023]
As an example, an example of detecting the number of semiconductor chip defects by measuring the weight of the substrate 2 will be described. When the substrate 2 is conveyed on the support rail 9 by the chuck 10 to the discharge position P, the claw portion 10b opens the substrate 2 and operates the lifting cylinder 16 to raise the measuring device support base 15, and the weight measuring device. When the 14 measurement mounting plates 14 b rise from the gaps between the support rails 9, the substrate 2 is received and the weight of the substrate 2 is measured. At this time, the resin discharge amount is corrected based on the difference between the weight when there are all the semiconductor chips and the weight when there are defects. As a result, the amount of liquid resin corresponding to the volume of the missing semiconductor chip can be increased and corrected according to the number of missing semiconductor chips depending on the substrate 2, so that the optimum amount of liquid resin can be supplied for each substrate 2. Further, uniform molding can be performed by preventing the thickness of the entire package after compression molding from becoming thin or causing unevenness in the sealing resin to cause molding defects.
[0024]
Next, the weight measuring device 14 is moved down by the lifting / lowering cylinder 16 to place the substrate 2 on the support rail 9 again, and then the liquid resin is discharged by the dispenser 13. When the liquid resin is discharged onto the substrate 2 by the dispenser 13 and the chuck 10 releases the substrate 2, the elevating cylinder 16 is activated to raise the measuring device support 15, and the measurement mounting plate 14 b is between the support rails 9. The substrate 2 is received when rising from the gap, and the weight of the substrate 2 is measured. Then, the resin amount of the liquid resin is calculated from the substrate weight before and after the application of the liquid resin, and the resin amount can be finely adjusted in comparison with the target discharge amount and an allowable value based on the target discharge amount.
[0025]
Hereinafter, a method for detecting a defective portion of a semiconductor chip based on workpiece weight measurement will be described in detail. The number of regular chips that can be mounted on the substrate 2 is A, the number of chips actually mounted on the substrate 2 is A ′, the amount of resin M applied to the substrate with the regular number of chips, and 1 chip are replenished. The amount of resin is m, the weight per chip is w, and the weight of a single substrate is T.
The normal workpiece weight W when there is no chip omission is given by W = (T + Aw). Therefore, assuming that the workpiece weight taking into account the chip omission measured by the weight measuring device 14 is W ′, W ′ = (T + A 'W).
When the number of chips A ′ mounted on the workpiece is obtained from this equation,
A ′ = (W′−T) ÷ w
Next, the number C of chips missing on the substrate 2 is obtained. C = A-A '
Finally, when the corrected resin amount M ′ is obtained, M ′ = M + Cm. The liquid resin having the corrected resin amount M ′ is measured and discharged onto the substrate 2 by the dispenser 13.
[0026]
As the means for detecting the number of defects of the semiconductor chip mounted on the work described above, various means can be adopted in addition to the work weight measurement. For example, the measurement result using any one of image processing performed by imaging the substrate 2 with the camera 12, measurement of the height of the semiconductor chip, change in reflectance of light obtained by irradiating the substrate 2 with light, etc. You may correct | amend based.
[0027]
Alternatively, the plate thickness of the workpiece may be measured before resin sealing, and the amount of liquid material taking into account the variation in the plate thickness of the workpiece may be discharged. For example, the plate thickness of the substrate 2 may be measured before resin sealing, and a liquid resin amount that takes into account variations in the plate thickness of the substrate 2 measured by the dispenser 13 may be discharged. As a result, the tolerance of the thickness of the workpiece after resin sealing (total workpiece thickness) can be narrowed, and if the amount of workpiece thickness variation is less than or equal to the maximum variation amount, the tolerance of the liquid material discharge amount is increased. It becomes possible.
[0028]
The dispenser 13 is preferably applied such that the central portion of the substrate 2 has a higher liquid material application height or a larger liquid material amount than the peripheral portion. That is, when the substrate 2 is clamped by the mold, the liquid resin applied to the central portion of the substrate 2 spreads to the peripheral portion, so that the air is expelled to the outside and effectively prevents air entrainment and void generation. This is because it can be done (see FIG. 7).
[0029]
Further, when the semiconductor chip is connected to the substrate 2 by wire bonding, it is difficult to fill the liquid resin between the narrow gap wires, and voids are easily generated. For this reason, it is preferable to apply the liquid resin by the dispenser 13 while vibrating the substrate 2 by the vibrator provided on the chuck 10 that holds the substrate 2.
Further, when the liquid resin is discharged onto the substrate 2 by the dispenser 13, the liquid resin may be applied while being heated to a temperature at which the liquid resin does not cure. Thereby, the flowability of the resin at the time of application can be improved, and the resin can enter the narrow gap between the wires of the semiconductor chip.
[0030]
Further, the nozzle 13a of the dispenser 13 may be a single nozzle or a multi-nozzle. However, since the liquid resin 45 uses a resin having a relatively high viscosity, the liquid resin is drawn in a single stroke on the substrate 2 in consideration of the fact that the liquid drainage shape tends to become unstable and the measurement tends to vary. 45 is preferably discharged. Specifically, an application pattern using a single nozzle is illustrated in FIGS. 7A to 7E, and an application pattern using a multi-nozzle is illustrated in FIGS. 7F to 7J. In this way, by applying the liquid resin 45 in an arbitrary pattern, the amount of resin movement during compression molding is reduced, and the wire flow or disconnection of the wire-bonded semiconductor chip is caused by the semiconductor chip defect portions 2a and 7a. It is possible to prevent the resin movement from being hindered and causing molding defects. In addition, the liquid resin application time can be shortened, and air can easily escape from between the resins.
Further, the liquid resin 45 applied to the substrate 2 from the dispenser 13 is applied so that the central portion of the substrate is higher in the resin coating height or the coating amount than the peripheral portion without involving air. It is desirable for rolling the resin. For example, as shown in FIGS. 7 (k) and 7 (l) and FIGS. 7 (h) to (j), it is applied in an arbitrary shape so that the coating height of the resin at the center is high or the coating amount is large. Is possible.
In addition, when a multi-nozzle is used, it is desirable to adjust the inter-nozzle pitch and the nozzle diameter so that air is not caught at the interface between the liquid resins 45 discharged from the nozzle.
[0031]
Further, as shown in FIG. 8A, the dispenser 13 may include a flat nozzle 13b having a wide liquid material discharge port 13c. As an example, the liquid material discharge port 13c may include a wide flat nozzle 13b having a cross section substantially equivalent to the cross section of the package resin portion. When the wide flat nozzle 13b is used, there is an advantage that there is little air entrainment and the application time can be shortened (application can be performed by one scan).
Further, as shown in FIGS. 8B and 8C, the dispenser 13 may discharge a liquid resin 45 having a range equivalent to the area of the package part 2b and a height 2c equivalent to the package part 2b.
In this case, since the height of the liquid resin 45 at the time of compression molding is low, the flow amount is reduced. Further, since the height of the liquid resin 45 is low, the mold clamping speed can be reduced without increasing the time required to compress the liquid resin (without exceeding the resin curing time). That is, since the flow rate of the liquid resin can be reduced, the wire flow (wire sweep) of the semiconductor chip hardly occurs. Further, since the amount of heat received by the liquid resin 45 after the substrate 2 is placed on the lower mold 18 is uniform, the viscosity change of the liquid resin 45 becomes uniform, and it is possible to make it difficult to cause a wire sweep.
[0032]
Next, an example of the liquid material discharge operation of the liquid material discharge device 8 will be described with reference to FIGS.
In FIG. 3, the front end of the substrate 2 sent out from the magazine 3 is chucked by the claw portion 10 b of the chuck 10 that is waiting at the end of the support rail 9, and is conveyed to the discharge position on the support rail 9. At this time, the substrate 12 is imaged by the camera 12 to detect the defective portion 2a of the semiconductor chip. The result of imaging the substrate surface is subjected to image processing to detect the number of chip defects, and the discharge amount of the liquid resin in the dispenser 13 is corrected. When the substrate 12 is not imaged by the camera 12, the number of chip defects 2 a may be detected by measuring the weight of the substrate 2 before applying the liquid resin by the weight measuring device 14.
[0033]
In FIG. 4, while the chuck 10 holds the substrate 2 at the discharge position, the dispenser 13 is scanned in the XYZ directions, and the amount of liquid resin 45 corrected according to the defective portion of the semiconductor chip is applied. The substrate 2 is discharged in an arbitrary pattern. At this time, the liquid resin 45 may be applied while vibrating the substrate 2 by vibrating the vibrator provided in the claw portion 10b.
[0034]
Next, in FIG. 5, the chuck of the substrate 2 by the chuck 10 is released, and the lifting cylinder 16 is operated. The measuring device support 15 is raised, the measurement mounting plate 14b is raised from between the support rails 9 to receive the substrate 2, and the substrate weight is measured by the measuring device main body 14a. As a result, it is determined whether or not the variation in the discharge amount of the liquid resin 45 is within the allowable range, and if it is within the allowable range, the process proceeds to the compression molding process. When the measurement of the substrate weight is completed, the measurement mounting plate 14 b is lowered and the substrate 2 is mounted on the support rail 9. Next, the loader 20 of the compression molding device 17 moves to the discharge position and receives the substrate 2 placed on the support rail 9 and conveys it to the lower mold 18.
[0035]
Here, the liquid resin discharge operation and discharge amount adjustment operation by the dispenser 13 will be described with reference to the flowchart shown in FIG. In addition, the chip | tip defect | deletion part 2a of a workpiece | work (board | substrate 2) shall be previously imaged by the camera 12, and the target discharge amount of the liquid resin 45 shall be set for every workpiece | work.
First, the weight of the substrate 2 is measured before discharging the liquid resin. When the substrate 2 is transported to the discharge position P of the support rail 9, the lifting cylinder 16 is operated to raise the measurement mounting plate 14b to receive the substrate 2, and the substrate weight is measured by the measuring device main body 14a. (Step S1). When the substrate weight is measured, the lifting cylinder 16 is actuated to lower the measurement mounting plate 14b and transfer the substrate 2 to the support rail 9 again.
[0036]
Next, the target discharge amount of the liquid resin 45 is calculated by the control unit of the liquid material discharge device 8 in consideration of the defective portion 2a of the semiconductor chip (step S2). Further, a discharge command aiming at the target discharge weight of the liquid resin 45 is sent to the dispenser 13, and the dispenser 13 scans the liquid resin 45 in the X, Y, and Z directions, and applies the liquid resin 45 to an arbitrary application pattern (FIG. 7). (A) to (l), see FIG. 8 (b)), the ink is discharged onto the substrate 2 (steps S3 and S4).
Next, the weight of the substrate 2 after discharging the liquid resin 45 is measured. That is, the lifting cylinder 16 is actuated to raise the measurement mounting plate 14b to receive the substrate 2 from the support rail 9, and the substrate weight is measured by the measuring device main body 14a (step S5). Here, the current discharge resin weight is calculated from the substrate weight before and after the discharge of the liquid resin 45 (step S6).
Here, the discharge coefficient of the dispenser 13 is updated so that the discharge weight of the liquid resin actually discharged from the dispenser 13 becomes the target discharge weight (step S7). The discharge coefficient is expressed as a ratio between the target discharge weight and the discharge command amount aiming at the target discharge weight.
[0037]
Next, the discharge weight actually discharged onto the substrate 2 is compared with the target discharge weight to determine whether or not it is within the allowable value range. As an example of the allowable value range, it is determined whether or not the variation of the discharge weight actually discharged with respect to the target discharge weight is a tolerance of ± 5% or less (step S8). If the discharge weight is out of the allowable value range, the process proceeds to step S9 to calculate a corrected discharge amount (= target discharge weight−discharge weight) and instruct the dispenser 13 to discharge the resin with the corrected discharge amount. The operations from S3 to S8 are repeated.
If the weight of the discharged resin is within the allowable range in step S8, the substrate 2 on which the liquid resin 45 has been discharged is transferred to the compression molding device 17 by the loader 20, and the next substrate 2 is transferred to the discharge position P of the support rail 9. Then, the same liquid resin discharge operation and discharge amount adjustment operation are performed.
[0038]
By the above operation of adjusting the resin discharge amount, it is possible to maintain high liquid resin application accuracy (resin amount accuracy). In particular, the amount of discharge due to the wear of the nozzle or seal of a dispenser (discharge device) that discharges liquid resin, the ambient temperature for resin sealing, the air mixed in the liquid resin, the viscosity of the liquid material itself, etc. Even if there is a factor such as a change, it is possible to maintain the molding quality by suppressing the variation in the discharge amount of the liquid resin within the allowable tolerance range.
[0039]
Next, another means for finely adjusting the variation in the discharge amount of the liquid resin by the dispenser 13 will be described with reference to FIG.
In this embodiment, based on the mold clamping movement information of the mold and the plate thickness information of the substrate 2, the dispersion of the resin discharge amount per work by the dispenser 13 can be adjusted within the allowable tolerance. It is assumed that the thickness of the substrate 2 is measured in advance and input to the control unit 49. The compression molding device 17 includes a servo motor 28 that opens and closes the mold. The rotation amount when the servo motor 28 is clamped is measured by the motor pulse measuring unit 46. Recognition of the completion of clamping of the mold is performed by detecting the clamping pressure by the clamping pressure detector 47. Specifically, the clamping pressure is detected by a pressure sensor (load cell) incorporated in the movable tie bar 50. When the value detected by the mold clamping pressure detector 47 exceeds a specified value, the motor driver 48 stops driving the servo motor 28. As a result, the discharge resin amount is converted by calculation from the rotation amount of the servo motor 28 and input to the control unit 49 of the liquid material discharge device 8. The controller 49 outputs a command to increase / decrease the resin discharge amount of the dispenser 13 to finely adjust the discharge amount of the liquid resin.
[0040]
For example, when the thickness of the substrate 2 (substrate thickness + resin thickness) is thin, the amount of rotation of the servo motor 28 increases, so fine adjustment is made to increase the amount of liquid resin compared to the amount of rotation calculated in advance. Further, when the thickness of the substrate 2 (substrate thickness + resin thickness) is large, the amount of rotation of the servo motor 28 is reduced. Therefore, the liquid resin is finely adjusted to reduce the amount compared with the amount of rotation calculated in advance.
Further, the liquid material discharge device 8 can appropriately maintain the resin amount after adjusting the resin discharge amount by measuring the weight of the adjusted liquid resin from the weight measuring device 14 and inputting it to the control unit 49. .
In addition, since the compression molding operation and the resin supply operation to the next substrate 2 are performed in parallel, based on the mold clamping movement information and the plate thickness information of the substrate 2, the liquid is supplied to the next substrate 2 with the adjusted discharge amount. Resin can be applied.
[0041]
Thus, by measuring the mold clamping position of the mold, adjustment based on the final thickness of the package portion can be performed, so that the coating accuracy is improved so that the variation in the discharge amount is within the allowable tolerance range. be able to.
[0042]
As described above, various preferred embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments. For example, means for correcting the amount of resin discharged by the dispenser 13 is not limited to weight measurement and image processing. Various other means can be adopted, and the coating pattern of the liquid resin on the workpiece is arbitrary. Furthermore, in addition to the liquid resin, powder resin, granule resin, etc. can be used as the liquid material. The type (material, viscosity, curing temperature, etc.) can be changed as appropriate.
Further, when a lead frame is used as a workpiece, even if a tape is attached to the bottom of the lead frame in order to prevent the liquid resin 45 having a reduced viscosity from flowing down from the hole formed in the lead frame. good.
Further, the rectangular workpiece (substrate 2) is illustrated in the case where the package part 2b is formed at one place as shown in FIG. 13A (when the cavity is formed at one place in the mold). However, as shown in FIG. 13B, in order to reduce the warp of the workpiece (substrate 2), the package portion 2b may be provided in a plurality of locations in the longitudinal direction (a plurality of cavities in the mold). Of course, many modifications can be made without departing from the spirit of the invention.
[0043]
【The invention's effect】
According to the liquid material discharge device according to the present invention, the liquid material amount individually defined for each work based on the work weight and / or the compression molding liquid material amount measured by the weighing means, and the work by the discharge means. The liquid material can be discharged on the top, and an amount of the liquid material for compression molding that is individually defined for each work can be accurately applied in an arbitrary pattern.
In particular, by measuring the number of semiconductor chips mounted on the workpiece and comparing it with the number of semiconductor chips assumed not to be missing, the missing semiconductor chip depends on the missing portion of the semiconductor chip that varies from workpiece to workpiece. Since the amount of the liquid material corresponding to the volume of the workpiece can be increased, the optimum amount of the liquid material can be individually supplied to the workpiece.
In addition, the weighing means can finely adjust the variation in the discharge amount of the liquid material per work by the discharge means within the allowable tolerance range by measuring the weight of the work before and after the discharge of the liquid material. Fine adjustment of the discharge amount of the liquid material can be finely performed every time, the application accuracy of the liquid material can be maintained with high accuracy, and the tolerance of the package can be reduced by reducing the variation in the thickness of the package. In particular, factors such as wear on the nozzle or seal of the discharge means that discharges the liquid material, ambient temperature for sealing, air mixed in the liquid material, changes in the discharge amount due to variations in the viscosity of the liquid material, etc. Even if there is, variation in the liquid material discharge amount can be suppressed within an allowable tolerance range.
In addition, when adjusting the variation in the discharge amount of the liquid material per workpiece by the discharge means within the allowable tolerance range based on the mold clamping position information of the mold and the workpiece thickness information, the final molded product Since the discharge amount can be adjusted based on the thickness of the liquid, the discharge accuracy of the liquid material can be improved so that the variation in the discharge amount is within the allowable tolerance range.
In addition, when the workpiece thickness is measured before resin sealing and the amount of liquid material is taken into account, the tolerance of the total workpiece thickness can be reduced. If the thickness variation amount is equal to or less than the maximum variation amount, it is possible to widen the tolerance of the liquid material discharge amount.
The liquid material discharge device of the present invention can obtain the same effect even if it is replaced with a powder resin or granule resin discharge device in addition to the liquid resin discharge device.
In addition, in a resin sealing device using a liquid material discharge device, the thickness of the entire package after compression molding is reduced or unevenness is generated in the sealing resin to prevent molding defects. It becomes possible to perform quality molding.
[Brief description of the drawings]
FIG. 1 is a plan view of a liquid material discharge device.
FIG. 2 is a front view of the liquid material discharge device of FIG.
FIG. 3 is an explanatory diagram of a liquid material discharge operation of the liquid material discharge apparatus.
FIG. 4 is an explanatory diagram of a liquid material discharge operation of the liquid material discharge apparatus.
FIG. 5 is an explanatory diagram of a liquid material discharge operation of the liquid material discharge apparatus.
FIG. 6 is a flowchart showing an operation of adjusting the liquid material discharge amount.
FIG. 7 is an explanatory diagram illustrating a coating pattern of a liquid material on a workpiece.
FIG. 8 is an explanatory diagram illustrating a nozzle shape of a dispenser and a liquid material application method.
FIG. 9 is an explanatory block diagram illustrating a liquid material discharge amount adjusting mechanism according to another example.
FIG. 10 is a plan view of the resin sealing device.
11 is a front view of the resin sealing device of FIG. 10;
FIG. 12 is an explanatory diagram of a workpiece.
FIG. 13 is an explanatory view showing an application pattern of a liquid material according to another example.
[Explanation of symbols]
1 Work supply section
2 Substrate
3 Magazine
4 Actuator
5 Cutting plate
6 Elevator mechanism
7 Silicon wafer
8 Liquid material discharge device
9 Support rail
10 Chuck
11 Guide rail
12 Camera
13 Dispenser
13a nozzle
14 Weight measuring device
14a Measuring device body
14b Mounting plate for measurement
15 Measuring device support
16 Lifting cylinder
17 Compression molding equipment
18 Lower mold
19 Upper mold
20 Loader
21 release film
22 Film transport mechanism
22a Supply reel
22b Take-up reel
23a Upper movable platen
23b Lower movable platen
24 Fixed platen
25 Screw shaft
26 nuts
27, 29, 40, 41 Pulley
42 Servo motor
30, 39 Timing belt
31 Unloader
32 Molded product storage device
33 Moving table
34 Pickup device
35 storage magazine
36 Z-axis moving arm
37 X-axis moving arm
38 Y-axis moving arm
43 Cylinder base
44 Guide post
45 Liquid resin
46 Motor pulse measurement unit
47 Mold clamping pressure detector
48 Motor driver
49 Control unit
50 Movable tie bar

Claims (12)

In a liquid material discharge device that discharges a predetermined amount of liquid material for compression molding to a workpiece,
A chuck that transports the workpiece fed from the workpiece supply unit to the discharge position on the support rail;
A discharging means for discharging the liquid material while scanning the transported to the discharge position the workpiece in the X-Y-Z directions,
A measuring means for measuring the weight of the workpiece discharged with the liquid material ;
A control unit for controlling the liquid material discharge operation of the discharge means by the amount of liquid material individually defined for each workpiece ;
The measuring means has a measuring device body provided with a measurement mounting plate supported so as to be able to move up and down below the discharge position of the support rail, and the measurement mounting plate arranged in the gap between the support rails moves up and down. When the workpiece is received from the support rail and measured, the control unit adjusts the corrected discharge amount so that the difference between the discharge weight of the liquid material actually discharged from the measured workpiece weight and the target discharge weight falls within the allowable range. A liquid material discharge device that calculates and instructs a discharge command of a corrected discharge amount to the next workpiece by the discharge means . The number of semiconductor chip defects in the workpiece is measured by any one of the following: measuring the weight of the workpiece, image processing performed by imaging the workpiece, measuring the chip height, and changing the reflectance of light obtained by irradiating the workpiece with light. The liquid material discharge apparatus according to claim 1, wherein the liquid material is discharged from the discharge means after increasing the amount of liquid material corresponding to the defective portion.   The measuring means is capable of finely adjusting the variation in the discharge amount of the liquid material per work by the discharge means within an allowable tolerance range by measuring the weight of the work before and after the discharge of the liquid material. The liquid material discharge device according to claim 1. Based on the mold clamping movement information of the mold and the workpiece thickness information measured in advance , it is possible to finely adjust the variation in the discharge amount of the liquid material per workpiece by the discharge means within an allowable tolerance range. The liquid material discharge device according to claim 1.  2. The liquid material discharge device according to claim 1, wherein the thickness of the workpiece is measured before resin sealing, and the amount of the liquid material is discharged in consideration of variations in the thickness of the workpiece.  2. The liquid material discharge device according to claim 1, wherein the discharge means applies the liquid material so that a central portion of the workpiece has a higher application height or a larger application amount than a peripheral portion. 2. The liquid material discharging apparatus according to claim 1, wherein when applying the liquid material to the workpiece by the discharging means, the liquid material is applied while vibrating the workpiece through the chuck .  2. The liquid material discharging apparatus according to claim 1, wherein when the liquid material is applied to the workpiece by the discharge means, the liquid material is applied while being heated.  2. The liquid material discharge apparatus according to claim 1, wherein the discharge means is a dispenser having a single nozzle or a multi-nozzle.  2. The liquid material discharge apparatus according to claim 1, wherein the discharge means is a dispenser provided with a flat nozzle having a wide liquid material discharge port. 11. A resin sealing device, wherein a liquid resin is supplied to a product to be molded by using the liquid material discharge device according to any one of claims 1 to 10 , and compression molding is performed. A servo motor is provided as a drive source for opening and closing the mold, and based on the clamping movement information obtained by measuring the rotation amount of the servo motor when clamping the mold and the plate thickness information of the workpiece measured in advance , The resin sealing device according to claim 11, wherein compression molding is performed by finely adjusting a liquid material discharge amount of the liquid material discharge device.

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