JPH05206186A - Resin sealing device and manufacturing of semiconductor device - Google Patents

Abstract

PURPOSE:To acquire a resin sealing device which can inject resin at a uniform and proper pressure by realizing a configuration which can detect in upper limit or a lower limit of a detection part at once by a detection means during vertical motion of a plurality of plungers. CONSTITUTION:A hole 29 is provided to a plunger rod 13 and a hole 30 is provided to a bottom force stand 10. A light emitting part 31b is fixed one side of the bottom force stand 10 and a photosensitive part 31b is fixed to the other side thereof. During normal injection of resin, light from the light emitting element 31a passes through the holes 30, 29 and attains the photosensitive element 31b. If a resin tumbler 7 is large, the plunger rod 13 is depressed; therefore, light from the light emitting part 31a is cut off at an upper side of the hole 29 and does not attain the photosensitive part 31b. In the process, a cutoff signal is provided to a motor 22 from the photosensitive part 31b and the motor 22 stops in response to the cutoff signal, thereby stopping a rise of the plunger rod 13. Therefore, excessive resin is not injected to the cavity 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin sealing device for injecting resin into a cavity of a mold in which a semiconductor element is housed by vertically moving a plunger to seal the semiconductor element and a plurality of plungers. The present invention relates to a method for manufacturing a semiconductor device in which a resin is injected into each cavity of a mold in which a plurality of semiconductor elements are housed by vertical movement, and the plurality of semiconductor elements are collectively sealed with resin.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view of a conventional resin sealing device. In the figure, 1 is a lead frame, 2 is a semiconductor element mounted on the lead frame 1, 3 is an upper mold, 4 is a lower mold, and 5 is a gate which is a route of a molten resin provided in the upper mold 3, 6 is a cavity provided in the upper mold 3 and the lower mold 4 for sealing and molding the semiconductor element 2 on the lead frame 1, 28 is a cavity for supplying molten resin to the cavity 6 through the gate 5, 7 Is a resin tablet which is a resin material.

Reference numeral 8 denotes a pot provided in the lower mold 4 for accommodating the resin tablet 7, 9 denotes an upper platen for mounting and fixing the upper mold 3, 10 denotes a lower mold base to which the lower mold 4 is mounted, 11
Is a movable platen to which the lower mold base 10 is fixed and which can slide up and down, and 100 is a plunger, which is composed of a plunger head 12 for injecting molten resin into the mold, and a plunger rod 13 connected to the plunger head 12. Reference numeral 14 is a compression spring that applies tension to the plunger rod 13, and 15 is a spring case that also serves as a retainer for the plunger rod 13 and that houses the compression spring 14.

Reference numeral 16 is a ball screw shaft, 17 is a nut holder for connecting the ball screw shaft 16 and the spring case 15, and 18
Is a bearing that supports the ball screw shaft 16 and receives a reaction force, 19
Is a bearing retainer for fixing the bearing 18 to the moving platen 11, and 2
0 is a driven pulley attached to the ball screw shaft 16, 21
Is a nut that fixes the driven pulley 20 and the ball screw shaft 16 and applies a preload to the bearing 18. 22 is a motor, 23
Is a speed reducer that reduces the rotational speed of the motor 22, and 24 is a motor part (the motor 22 and the speed reducer 23) that moves the platen 1.
1 is a motor mounting plate fixed to 1, 25 is a driving pulley fixed to the output shaft of the speed reducer 23, and 26 is a belt for transmitting the rotational torque of the driving pulley 25 to the driven pulley 20.

Next, the operation will be described. 180 ° C each
The lead frame 1 on which the semiconductor element 2 is mounted is set on the lower mold 4 by a loader (not shown) with the upper mold 3 and the lower mold 4, which are heated and kept warm, are opened and The tablet 7 is loaded into a pot 8 by a loader (not shown).
Throw in. After that, the movable platen 11 rises, and the upper die 3 and the lower die 4 are clamped and pressed. Then, when the resin tablet 7 is melted, the motor 22 attached to the moving platen 11 is driven to drive the reduction gear 23, the driving pulley 25, the belt 26, the driven pulley 20, the ball screw shaft 1
6, the plunger head 12 rises via the nut holder 17, the compression spring 14, and the plunger rod 13. As the plunger head 12 rises, the molten resin is injected into the cavity 6 via the cull 28 and the gate 5. here,
When injecting the molten resin into the cavities 6, the compression springs 14 corresponding to the respective plunger rods 13 absorb the variations in the amount of the resin tablets 7 and the heights of the respective plunger heads 12 to control the pressure to be injected into the respective cavities 6. The following settings are made in advance in order to make them uniform.

F1 = P × A, F2 = k × x, F1> F2 where F1 is the injection force (kgf) of the molten resin, F2 is the initial load (kgf), and P is the injection pressure of the molten resin (kgf / kgf /
cm ² ), k is the spring constant (kgf / mm), A is the pot area (cm ² ), x is the initial deflection (m) of the compression spring 14.
m). For example, injection pressure F1 of 70 kgf / cm ²
In contrast, an initial load F2 of 60 kgf / cm ² is set.

When the injection of the resin into the cavity 6 is completed, the plunger 100 is returned to the lower position. And upper mold 3
The lower die 4 is opened, and the semiconductor element 2 which is resin-sealed integrally with the lead frame 1 is taken out. After that, the lead frame 1 on which the semiconductor element 2 is mounted is set again on the lower mold 4, the resin tablet 7 is put into the pot 8, and the resin is poured into the cavity 6 again. This operation is repeated to manufacture a plurality of resin-sealed semiconductor devices.

[0008]

Since the conventional resin sealing device is constructed as described above, when the amount of resin to be injected into the cavity 6 (the amount of the resin tablet 7) is large, the compression in the spring case 15 is performed. Since the spring 14 exceeds the allowable deflection size, resin is injected into the cavity 6 at an abnormally high pressure, or the compression spring 1 increases in return stress.
4 has a problem that plastic deformation (the length of the compression spring 14 in the initial state becomes short) occurs and a uniform injection pressure cannot be obtained. Further, when the gate 5 communicating with the cavity 6 is clogged, residual resin exists on the cull 28 or on the plunger head 12 when the plunger 100 makes one reciprocation. If the resin tablet 7 is put into the pot 8 again from this state and the plunger 100 is raised to inject the resin into the cavity 6, the same problem as described above occurs.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a resin encapsulating device and a method for manufacturing a semiconductor device in which resin can be injected uniformly and at an appropriate pressure. ..

[0010]

A resin sealing device according to the present invention seals a semiconductor element by injecting resin into each cavity of a mold in which the semiconductor element is housed by the vertical movement of a plunger. In the resin sealing device, the detection part having a predetermined width provided on the plunger, and a detection means for detecting an upper limit of the detection part or a lower limit of the detection part when the plunger moves up and down, When a plurality of the plungers are provided and the resin is injected into the corresponding cavities by the plurality of plungers, the detection unit collectively sets the upper limit or the lower limit of the detected parts when the plurality of plungers move up and down. The feature is that the shape can be converted.

A method of manufacturing a semiconductor device according to the present invention is
Resin is injected into each cavity of a mold containing a plurality of semiconductor elements by vertical movement of a plurality of plungers,
In a method for manufacturing a semiconductor device in which a plurality of semiconductor elements are collectively sealed with resin, the plurality of semiconductor elements are collectively detected while collectively detecting an upper limit or a lower limit of vertical movement of the plurality of plungers during vertical movement of the plurality of plungers. And resin sealing is performed.

[0012]

In the resin sealing device according to the present invention, the detected part provided on the plunger has a predetermined width and the detection means for detecting the upper limit or the lower limit of the detected part when the plunger moves up and down. When a plurality of plungers are provided and the resin is injected into the corresponding cavities by the plurality of plungers, the portion has a shape such that the upper limit or the lower limit of the detected portions can be collectively detected by the detecting means during the vertical movement of the plurality of plungers. Therefore, when a resin is injected into the cavity by a so-called multi-plunger method and a plurality of semiconductor elements are collectively resin-sealed, a plurality of plungers can be collectively packaged without providing detection means for each of the plurality of plungers. It is possible to detect the upper limit or the lower limit of the detected portion provided in the.

In the method of manufacturing a semiconductor device according to the present invention, when a plurality of plungers are moved up and down, the upper and lower limits of the up and down movements of the plurality of plungers are collectively detected, and the plurality of semiconductor elements are collectively sealed with resin. Therefore, when a plurality of semiconductor elements are collectively resin-sealed by the so-called multi-plunger method, it is not necessary to detect the upper limit or the lower limit for each plunger.

[0014]

1 is a sectional view showing an embodiment of a resin sealing device according to the present invention, and FIG. 2 is a plan view of the device shown in FIG. In the figure, the difference from the conventional device shown in FIG. 3 is that a hole 29, a hole 30, a transmission sensor including a light emitting portion 31a and a light receiving portion 31b, and a sensor holder 32 are newly provided. The hole 29 is provided so as to penetrate the plunger rod 13, and the hole 30 is provided so as to penetrate the lower mold base 10. The light emitting portion 31a and the light receiving portion 31b are supported and fixed on both side surfaces facing the lower mold base 10 by the sensor holder 32, respectively.
The supporting and fixing positions are such that the light from the light emitting portion 31a passes through the holes 29 and 30 in the ordinary resin injection operation and the light receiving portion 3
This is the place to reach 1b. In FIG. 1, for convenience of drawing, the hole 29, the hole 30, the light emitting portion 31a, the light receiving portion 31b, and the sensor holder 32 are in the same cross section (XX cross section and Y- cross section in FIG. 2).
Although it is shown above (composite cross section of Y cross section), each component is actually arranged at the position shown in FIG. Other configurations are the same as those of the conventional device shown in FIG.

Next, the operation will be described. Cavity 6
The method of injecting the resin into the inside is the same as the conventional method. That is, the resin tablet 7 dissolved by raising the plunger head 12 is injected into the cavity 6 through the cull 28 and the gate 5. In a normal resin injection operation, the width of the hole 29 is set so that the vertical movement of the plunger rod 13 does not block the light from the light emitting portion 31a from reaching the light receiving portion 31b. Specifically, the width of the hole 29 is set to a width that blocks light from the light emitting portion 31a when the deflection amount of the compression spring 14 exceeds the allowable deflection amount.

The abnormality detection when an abnormality occurs during the resin injection into the cavity 6 will be described below. First, a case will be described in which the length of the resin tablet 7 stored in the pot 8 is longer than the normal length (length at which the amount of resin injected into the cavity 6 is appropriate). In this case, the plunger rod 13 is pushed downward more than usual, and the deflection amount of the compression spring 14 becomes equal to or larger than the allowable deflection amount. Then, the light from the light emitting portion 31a is blocked by the upper surface of the hole 29 provided in the plunger rod 13. The light receiving unit 31b detects this light blocking state, and the light receiving unit 31b sends a light blocking signal to the motor 22. The motor 22 stops in response to the light shielding signal, and in response thereto, the vertical movement of the plunger 100 stops. Therefore, more resin than is necessary
Is not injected into the compression spring 14, and the pressure that makes the deflection amount of the compression spring 14 larger than the allowable deflection amount is not applied, so that the plastic deformation of the compression spring 14 is less likely to occur.

Next, the case where the gate 5 is clogged will be described. When the gate 5 is clogged, the resin is not completely injected into the cavity 6 by one reciprocating motion of the plunger 100, and the residual resin remains on the cull 28 or the plunger head 12. When the resin tablet 7 to be injected next is placed in the pot 8 in this state, the plunger 5 is more likely than when the resin tablet 7 is accommodated in the pot 8 in a normal resin injection state where the gate 5 is not clogged due to the presence of residual resin. The rod 13 is pushed down, and the light emitting unit 3
The light from 1a is blocked by the upper surface of the hole 29. Therefore, as described above, the vertical movement of the plunger 100 is stopped, and it is possible to prevent the resin from being injected into the cavity 6 more than necessary, and a pressure such that the deflection amount of the compression spring 14 becomes larger than the allowable deflection amount. It is not applied, and the plastic deformation of the compression spring 14 is less likely to occur.

Next, a case where the compression spring 14 is plastically deformed will be described. In this case, when the resin tablet 7 is housed in the pot 8, the plunger rod 13 is positioned lower than the normal operation, and the light from the light emitting portion 31a is blocked by the upper surface of the hole 29. Therefore, when the compression spring 14 is plastically deformed, the resin injection into the cavity 6 is stopped, and the plastic deformation of the compression spring 14 can be detected.

Next, when the resin tablet 7 is not stored in the pot 8 or when the resin tablet 7 is stored in the pot 8 but its length is shorter than the normal length (cavity 6).
The case where the amount of resin injected into the resin decreases) will be described.
In such a state, when the plunger 100 is raised and resin is injected into the cavity 6, the plunger rod 1
3 moves more than usual. As a result, hole 29
Light from the light emitting portion 31a is blocked by the lower surface of the. for that reason,
It is possible to detect the situation where the resin injection amount becomes small.

The above-mentioned light-shielding signal is generated when even one of the plurality of plunger rods 13 provided blocks light from the light emitting portion 31a. Therefore, multiple plungers 100
Thus, in the multi-plunger type resin encapsulation device which encapsulates the semiconductor elements in a lump, it is possible to detect the abnormality at the time of resin injection in a lump by the pair of transmission sensors of the light emitting portion 31 and the light receiving portion 31b.

As described above, since an abnormality at the time of resin injection can be detected, appropriate resin injection can be performed by taking measures against the abnormality.

In the above embodiment, the plunger rod 1
3 and the lower mold base 10 are provided with holes 29 and 30 respectively, the plunger head 12 and the lower mold 4 are provided with holes respectively so that light from the light emitting portion 31a can pass therethrough. However, the same effect as that of the above embodiment is obtained.

Further, in the above-mentioned embodiment, the configuration is such that the abnormality at the time of injecting the resin into all the pots corresponding to the lead frame is collectively detected, but the light emitting portion 31a and the light receiving portion 31b are provided for each pot and the resin is provided for each pot. Even if an abnormality at the time of injection is detected or an abnormality at the time of resin injection of the corresponding pot in the plurality of lead frames is detected by providing the light emitting portion 31a and the light receiving portion 31b on the line X-X in FIG. It has the same effect as the embodiment. In addition, in FIG.
1b is provided with a return reflection means, and one of the two light emitting portions 31a is used as a light receiving portion, and the light from the light emitting portion 31a is reflected by the reflection means and returned to the side of the adjacent pot row to form two leads. By allowing light to pass through the holes of the plunger rods corresponding to all the pots of the frame, it is possible to collectively detect the abnormality at the time of injecting the resin into all the pots of the plurality of lead frames.

Further, in the above-described embodiment, the case where the hole 29 is provided in the plunger rod 13 has been described, but a recess is provided in the side surface of the plunger 13 instead of the hole, and the light from the light emitting portion 31a passes through this recess and is received. You may make it reach | attain the part 31b. Furthermore, the plunger rod 13
When the resin is injected into the corresponding cavities by a plurality of plungers, the measured part with a predetermined width is set to the upper limit or the lower limit of the measured part provided on the plunger when the plungers move up and down. Part 31a
It is not limited to a hole or a concave as long as it has a shape that can be collectively detected by the light receiving section 31b).

Further, in the above-mentioned embodiment, the plunger rod 1 is constituted by the transmission sensor including the light emitting portion 31a and the light receiving portion 31b.
Although the upper limit or the lower limit of the hole 29 provided in No. 3 is detected, the contact sensor is used for each plunger rod 13
Even if the upper limit or the lower limit of the hole 29 provided in each plunger rod 13 is individually detected, the abnormality at the time of resin injection can be detected. Further, even if a reflection sensor is provided and the upper limit or the lower limit of the holes 29 provided in each plunger rod 13 is collectively detected, the same effect as in the above embodiment can be obtained.

Further, in the above embodiment, the width of the hole 29 is set so that the light-shielding signal is output when the deflection amount of the compression spring 14 at the time of resin injection exceeds the allowable deflection amount. (For example, 100 kgf / cm ² ) The width of the hole 29 may be set so as to generate a light-shielding signal when the deflection amount of the compression spring 14 that exerts a considerable force is exceeded.

[0027]

As described above, according to the resin sealing device of the first aspect, the upper limit or the lower limit of the detected portion of the predetermined width provided on the plunger and the upper or lower limit of the detected portion during the vertical movement of the plunger are detected. When a plurality of plungers are provided and the resin is injected into the corresponding cavities by the plurality of plungers, the upper and lower limits of the detected portions are detected when the plurality of plungers move up and down. Since it has a shape that allows collective detection by using a so-called multi-plunger method, when a resin is injected into the cavity and a plurality of semiconductor elements are collectively sealed with resin, a detection unit corresponding to each plunger is provided. It is possible to collectively detect the upper limit or the lower limit of the detected portions provided on the plurality of plungers without providing them. As a result, it is possible to detect abnormalities when resin is injected into the cavities by the multi-plunger method, and it is possible to always keep the resin injection amount and injection pressure of each cavity constant by taking appropriate measures against the abnormalities. effective.

According to the method of manufacturing a semiconductor device of the second aspect, the upper and lower limits of the vertical movements of the plurality of plungers are collectively detected during the vertical movements of the plurality of plungers, and the plurality of semiconductor elements are collectively sealed with resin. Since it is configured to stop, it is not necessary to detect the upper limit or the lower limit for each plunger when a plurality of semiconductor elements are collectively resin-sealed by the so-called multi-plunger method. As a result, it is not necessary to provide a means for detecting the upper limit or the lower limit for each plunger, and it is possible to detect an abnormality when the resin is injected into the cavity by the multi-plunger method, and take appropriate measures against the abnormality. This has the effect that the resin injection amount and injection pressure in each cavity can be kept constant at all times.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a resin sealing device according to the present invention.

2 is a plan view of the device shown in FIG. 1. FIG.

FIG. 3 is a diagram showing a configuration of a conventional resin sealing device.

[Explanation of symbols]

 2 semiconductor element 3 upper mold 4 lower mold 6 cavity 7 resin tablet 29, 30 hole 31a light emitting part 31b light receiving part 100 plunger

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[Procedure amendment]

[Submission date] May 21, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

Reference numeral 8 denotes a pot provided in the lower mold 4 for accommodating the resin tablet 7, 9 denotes an upper platen for mounting and fixing the upper mold 3, 10 denotes a lower mold base to which the lower mold 4 is mounted, 11
Is a movable platen to which the lower mold base 10 is fixed and which can slide up and down, and 100 is a plunger, which includes a plunger head 12 for injecting molten resin into the mold and a plunger rod 13 connected to the plunger head 12. Reference numeral 14 is a compression spring that applies tension to the plunger rod 13, and 15 is a spring case that also serves as a retainer for the plunger rod 13 and that houses the compression spring 14.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

[0008]

Since the conventional resin sealing device is constructed as described above, when the amount of resin to be injected into the cavity 6 (the amount of the resin tablet 7) is large, the compression in the spring case 15 is performed. Since the spring 14 exceeds its allowable deflection size, the resin is injected into the cavity 6 at an abnormally high pressure, or the torsion spring of the compression spring 14 increases and the compression spring 1
4 has a problem that plastic deformation (the length of the compression spring 14 in the initial state becomes short) occurs and a uniform injection pressure cannot be obtained. Further, when the gate 5 communicating with the cavity 6 is clogged, residual resin exists on the cull 28 or on the plunger head 12 when the plunger 100 makes one reciprocation. If the resin tablet 7 is put into the pot 8 again from this state and the plunger 100 is raised to inject the resin into the cavity 6, the same problem as described above occurs.

Claims (2)

[Claims] 1. A resin sealing device for injecting a resin into a cavity of a mold in which a semiconductor element is housed by vertically moving a plunger to seal the semiconductor element with a resin having a predetermined width provided in the plunger. The detection unit includes a detection unit that detects an upper limit or a lower limit of the detection unit when the plunger moves up and down, and the detection unit includes a plurality of the plungers, and the plurality of plungers respectively correspond to the inside of the cavity. In the case of injecting the resin into the resin, the resin sealing is characterized in that the upper limit or the lower limit of the detected portions provided on the plungers can be collectively detected by the detecting means when the plurality of plungers are vertically moved. apparatus. 2. A semiconductor device including a step of injecting a resin into each cavity of a mold accommodating a plurality of semiconductor elements by vertically moving a plurality of plungers and encapsulating the plurality of semiconductor elements with a resin. In the manufacturing method of the semiconductor device, the plurality of semiconductor elements are collectively resin-sealed while collectively detecting the upper limit or the lower limit of the vertical movement of the plurality of plungers during the vertical movement of the plurality of plungers. Production method.