JPH06218754A - Resin molding device and control thereof - Google Patents

Abstract

PURPOSE:To easily mold a resin molded product having an extremely thin package and to facilitate gate break. CONSTITUTION:A pot 10 and a cavity 12 are allowed to communicate with each other by a resin passage 24 and a molten resin is sent to the cavity 12 under pressure from the pot 1 through the resin passage 24 to be subjected to resin molding. Gate runner pins 14a, 14b having flat end surfaces are arranged at the gate end positions of the cavity 12 and retracted at the time of the filling of the cavity 12 with the resin to open the resin passage and, after the cavity 12 is filled with the resin, the gate runner pins 14a, 14b are allowed to protrude and the end surfaces thereof are brought into contact with a product to be molded to close the resin passage 24 to perform resin molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin mold device used for manufacturing a resin mold type semiconductor device and a control method thereof.

[0002]

2. Description of the Related Art In the manufacture of a resin mold type semiconductor device, a transfer molding method is generally used in which a resin is pressure-fed from a pot into a cavity to fill the cavity with the resin for molding. By the way, recently, a product having an extremely thin resin package has been manufactured as a resin mold type product, and a product in which a TAB tape is directly resin-molded appears as a product using a TAB tape as a molded product. As a result, various problems have occurred in the resin molding operation.

For example, since the package is large and thin, the strength of the package is insufficient and the package is likely to warp after resin molding, and the thin package makes it difficult to fill the resin into the cavity. There are problems such as resin unfilling and generation of voids.
The thinner resin package means that the gate becomes narrower, which makes it difficult to fill the resin, and the resin flowability in the cavity is low, which makes it difficult for the resin to flow inside the cavity. Occurs. In the case where the TAB tape is resin-molded, the cavity is divided into upper and lower parts by the tape, so that there is a problem that the fluidity of the resin in the vertical direction is further lowered and the resin molding cannot be accurately performed.

Further, in the case of the conventional resin molding apparatus, the resin cured in the flow path for filling the cavity with the resin is always adhered to the product to be molded. Therefore, after the resin molding, it is necessary to perform a gate break operation for peeling and removing the unnecessary resin adhering to the molded product. Conventionally, the connecting portion between the cavity and the gate is formed into a squeezed shape so that the gate break can be easily performed so that the package body side is not damaged at the time of the gate break.
However, in the case of a very thin product with a resin package thickness of 0.5 mm or less, it is easy to damage the main body at the time of gate break, and in the case of TAB tape, the gate remaining on the tape remains. There is a problem that the product is deformed when peeling and removing.

The present invention has been made to solve these problems, and an object thereof is to enable resin filling even in the case of recent extremely thin products, and to mold resin-molded products. In order to provide a resin molding device and a control method therefor, which can improve the property and obtain a good product, facilitate the gate break operation, and can perform the gate break without adversely affecting the package body side. is there.

[0006]

The present invention has the following constitution in order to achieve the above object. That is, in a resin molding apparatus that connects a pot and a cavity by a resin path and sends molten resin from the pot to the cavity via the resin path to perform resin molding, the resin path at the gate end position of the cavity is molded. A gate runner pin whose end face that contacts the product is formed to be flat so that the resin path can be opened and closed so that it can be pushed in the mold opening and closing direction, and when the cavity is filled with resin, the gate runner pin is It is characterized in that a drive mechanism is provided for drawing the gate runner pin to a position where the end face of the gate runner pin comes into contact with the molded product after the path is opened and the cavity is filled with the resin. Further, the gate runner pin is arranged so as to face the upper mold and the lower mold with the molded product interposed therebetween. In addition, the end surface shape of the gate runner pin that contacts the molded product is pressed against the entire range from the gate end position of the cavity to the side edge of the molded product according to the resin path arrangement on the molded product. The feature is that it is provided. Also, in the control method for the resin molding device, the resin is melted by closing the pot and the inside of the resin passage by closing the resin passage by projecting the gate runner pin in a state where the resin is put in the pot. At the same time, the plunger compresses the resin to discharge the mixed gas in the resin out of the mold, then return the gate runner pin to the retracted position, open the resin passage and fill the cavity with the resin, and then the gate. The runner pin is extruded until the end surface of the runner pin contacts the molded product while removing the resin in the resin path, separating the cavity side and the pot side, and after the resin is cured, the mold is opened and the molded product is taken out. And

[0007]

When the resin is filled from the pot into the cavity, the gate runner pin opens the resin path leading to the cavity to inject the resin. This facilitates resin injection into the cavity. After the cavity is filled with the resin, the gate runner pin is inserted into the resin passage while removing the resin in the resin passage to close the resin passage. The cavity side and the pot side are separated by the gate runner pin, and in this state, the resin is cured and molded. By eliminating the resin in the resin path with the gate runner pin, the resin does not remain at the gate end position connected to the resin package, and the gate break in the subsequent process is unnecessary. Before the resin is injected into the cavity, the resin path is closed by the gate runner pin and the molten resin is compressed to expel gas such as water vapor and molten gas mixed into the resin to improve the quality of the molten resin. It is possible to improve the resin moldability and enhance the reliability of the package by injecting the resin from the cavity into the cavity.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is an explanatory diagram showing a configuration of an embodiment of a resin molding apparatus according to the present invention. The resin molding apparatus of the embodiment is characterized by arranging the gate runner pins 14a and 14b so as to divide the resin path at a midway position of the resin path connecting the pot 10 and the cavity 12 with each other. , 14b are provided so as to be movable in the mold opening / closing direction to enable a projecting / inserting operation according to the resin filling operation.

In the figure, the molded product 16 is clamped by the upper mold chase 18a and the lower mold chase 18b, and is filled with resin by the plunger 20. The structures of the chase block and the mold base that support the upper chase 18a and the lower chase 18b, the eject pin for releasing the molded product, and the like are similar to those of the known resin molding apparatus. The gate runner pins 14a and 14b are mounted on a chase so that the molded product 16 is sandwiched by the end faces of the molded product 16 from above and below on the resin path connecting the pot 10 and the cavity 12, and are provided on the upper mold and the lower mold at the respective base positions. Air cylinder 22
a, 22b. The air cylinders 22a and 22b drive the gate runner pins 14a and 14b back and forth in the axial direction.

FIG. 2 shows a plan view of the resin mold of the embodiment. The pot 10 is located on the side of the article 16 to be molded, and the pot 10 and the cavity 12 are connected by a resin path 24. The gate end for injecting the resin into the cavity 12 is provided at the corner portion of the cavity 12, and the molten resin is pumped into the cavity 12 from this corner portion. The gate runner pins 14a and 14b are formed in the cavity 12 as shown.
Align the outer surface with the corner of the
It arranges so that it may block.

3 (a), 3 (b), 4 (a) and 4 (b) show the operation of the resin molding apparatus of the above embodiment. First, the molded product 16 is first set on the lower mold chase 18b and lightly clamped between it and the upper mold chase 18a. Pot 10
The timing at which the resin is charged varies depending on the mechanical characteristics of the device. Further, in the embodiment, the resin tablet 26 is added as the resin agent, but the resin agent is not limited to the tablet shape, and a granular shape or a powder shape may be used.

Next, the gate runner pins 14a and 14b
Is pressed by an air cylinder to press the molded product 16 from both sides, thereby closing the resin path 24 in the middle, and the space formed by the pot 10 and the runner becomes a closed space. In this state, as shown in Fig. 3 (b), the plunger 2
0 is operated at medium pressure to compress the softening resin in this closed space. This compression operation completely melts the resin in this closed space, and the steam generated at the time of melting,
It is aimed to discharge the gas from the upper and lower mold parting surfaces and the air vent part together with the existing air, and to fill the resin with a uniformly molten resin that does not contain gas.

In the above melting operation, since the upper chase 18a and the lower chase 18b are not clamped at high pressure, unnecessary gas can be easily discharged from the parting surface. By setting the pushing pressure on the plunger 20 in advance, the plunger 20 automatically stops when the pressure of the plunger and the compression pressure in the closed space are balanced. A pressure sensor may be installed in the cull portion to stop the plunger 20 when the pressure of the molten resin reaches a certain pressure.

Examples of the gas mixed in the molten resin include water vapor absorbed by the resin, vaporized water vapor, gas generated in the process of melting the resin, and residual air in the pot 10 and the resin passage 24. In the conventional resin molding device, these gases are directly drawn into the resin and filled into the cavity, which may cause voids,
This causes the resin density to decrease and an air layer to be formed on the lower surface of the wafer.

In the case of the present apparatus, the gate runner pin 14a, before the resin is injected into the cavity as described above,
Since the operation of discharging the gas from the molten resin by closing the resin passage 24 by 14b, it becomes possible to inject the resin in a state of good resin quality. In this apparatus, a granular or powdery resin agent can be used because it is possible to perform the operation of removing the gas from the molten resin in this way. With conventional resin molding equipment, powder or granular resin agents cannot eliminate the gas that mixes with the resin, so they could hardly be used in the manufacture of semiconductor devices that require high-quality resin molding. Is.

Next, in the state where the resin melting shown in FIG. 3B is completed, the gate runner pins 14a and 14b are pulled back to the retracted position while the position of the plunger 20 is fixed.
The retracted position of the gate runner pins 14a and 14b is the same position as the cavity depth or a position slightly retracted from the cavity depth. Then, with the gate runner pins 14a, 14b retracted, the plunger 20 is operated at a low pressure to inject the resin into the cavity 12. By pulling the gate runner pins 14a and 14b into the pull-in position, the resin passage 24 is opened and the cavity 12 is filled with the resin from the upper and lower surfaces of the molded product 16.

FIG. 4A shows a state where the plunger 20 is pushed to fill the cavity 12 with resin. Resin road 2
No. 4 has a wider resin opening than the conventional gate section having a V-shaped cross section, and therefore has good resin flowability and can be easily filled with resin even when the injection pressure of the plunger 20 is low. . In the conventional resin molding, when the resin was ejected from the gate into the cavity, the air in the cavity was entrained by the resin to form a void and the like. Since it is deeper than the cavity depth, air is not entrained in the direction of gravity, and in addition, the resin speed when passing through the gate can be lower than in the past when entraining air in the horizontal direction. And so on, and resin moldability is improved. In particular, since air is discharged from the molten resin in the previous stage, the resin quality is good and good resin molding is possible.

Further, in the conventional resin molding apparatus, when the semiconductor chip cannot be properly resin-molded because the semiconductor chip is displaced from its normal position, tilted, or vibrates due to the resin pressure when the resin is ejected into the cavity. However, in the case of the present embodiment, since the resin speed is low, it is possible to suppress the effect of misaligning the semiconductor chip, and it is possible to mold the resin with high reliability. Further, since the resin speed is low, it becomes possible to effectively suppress the abrasion of the mold due to the collision and the rubbing with the resin agent at the gate portion. Further, when it is considered that the filler mixed in the resin is spherical silica or the like, the allowable dimension with respect to the diameter dimension thereof is larger than that of the conventional one, so that there is an effect of preventing the gate clogging.

After filling the cavity 12 with resin at a low pressure,
Plunger 20 with high clamping force for upper and lower molds
Switch to holding pressure control that presses at high pressure. In the pressure-holding step, the resin is cured by applying pressure to the cavity 12, but when the viscosity of the resin rises to a certain extent at this time, FIG. 4 (b)
The gate runner pins 14a and 14b are attached to the air cylinders 22a and 2 until the end surface comes into contact with the molded product 16 as shown in FIG.
Push with 2b to make it protrude. In this operation, the gate runner pins 14a and 14b project while removing the resin in the resin passage 24, so that the resin runs in the gate runner pin 14
It is necessary to start before reaching the limit viscosity that can be excluded by a and 14b.

By projecting the gate runner pins 14a, 14b, the pressing force of the gate runner pins 14a, 14b acts on the cavity 12 and the plunger 20 as well. End area 1.33 cm ² of the plunger 20 in the embodiment, gate runner pin 14a, the end area of the 14b is 0.3 cm ^2. Therefore, the gate runner pins 14a and 14b act to push back the plunger 20 with a force of 4.4 times. Further, when the gate runner pins 14a and 14b are projected, they may be projected with a pressing force that can resist the resin pressure at the time of holding pressure. For example, assuming that the resin pressure at the time of holding pressure is 70 Kgf / cm ² in the above example, a force equal to or larger than the sliding force added to the operating force of 70 × 0.3 = 21 Kgf is sufficient. In the embodiment, the gate runner pins are connected to the air cylinders 22a, 22
Although it is driven by b, the drive source of the gate runner pin is not limited to this, and an actuator such as a hydraulic cylinder or an electric motor can be used as appropriate.

After the resin passage 24 is closed by the gate runner pins 14a and 14b, the plunger 20 side and the cavity 12 side are separated from each other, and the cavity 12 is subjected to the plunger pressure as in the conventional case. The resin cures in the absence. When the resin curing is completed, the mold is opened and the molded product is taken out. Then, the operation of the gate runner pin is confirmed by pulling back the gate runner pins 14a and 14b from the projecting position to the retracted position, and the resin that has entered the outer periphery of the pin is cleaned. Then, the mold surface is cleaned to complete one cycle.

FIGS. 5 (a) and 5 (b) are a plan view and a side view of the resin molded product obtained as described above. By arranging the gate runner pins 14a and 14b on both sides of the molded product 16 and performing resin molding, a product in a state where the resin that cures at the gate portion that communicates with the package unit 30 does not remain on the molded product 16 is obtained. Obtainable. 32
Is the cull cured at the top of the pot 10. In this way, since the package portion 30 and the gate are not in communication with each other, it is possible to perform the operation of removing the gate and a part of the resin path without affecting the resin package 30.

When resin molding is actually performed using the gate runner pins, various patterns are possible as the arrangement positions of the gates and runners and the installation method of the gate runner pins depending on the product. 6, 7 and 8 show other examples of installation of gate runner pins. FIG. 6 shows an example in which a resin path 24 is provided on one surface (lower surface) of the molded product 16 and a gate runner pin is provided on one surface to perform resin molding. In this case, the resin is filled in the cavity only from the lower surface side of the molding target 16. FIG. 7 shows an example in which resin paths 24 are provided on the upper and lower surfaces of the molded product 16 and resin is filled in the same manner as in the above-described embodiment. It excludes resin.
By removing the gate and the resin passage on the upper surface, the removal operation of the resin passage on the lower surface is facilitated.

In FIG. 8, resin passages are provided on the upper and lower surfaces of the molded product 16 to inject resin, and the gate runner pins are extended from the gate end of the resin package 30 to the outside of the side edge of the molded product 16 to form the molded product. This is an example of resin molding so that no resin remains on the molded product 16. In this way, if the cured resin is removed from the molded article 16 and the resin is molded, the operation of removing the resin passage after the resin molding becomes completely unnecessary. In the case of products such as TAB tapes, the resin molding method that does not require the gate breaking operation is extremely suitable.

Although each of the above-described embodiments is a quad type product having leads in four directions, it can be similarly applied to a product having bidirectional leads. FIG. 9 shows an example thereof. Also in the case of this product, it is the same that the resin path is provided on the molded product 16 from the side edge thereof. The gate runner pins 14a and 14b are arranged such that the side edges of the cavity 12 can be closed in the upper mold and the lower mold, respectively. The gate runner pin 14a is provided so as to close the entire side edge of the cavity 12 as shown in FIG. 9 (a), and the molten resin is filled from the entire width of the cavity 12. In the embodiment, the gate runner pin 14a is set to the width 14 of the cavity 12.
It is preferable to design the gate runner pin 14a to be wider than the width a in the width direction when the molten resin is filled from the entire width of the cavity 12 because it is easier to damage the gate runner pin 14a because of the mold structure. That's why. In addition, it is easier to obtain a clearance and to improve machining accuracy when the side end surface is rounded rather than when the gate runner pin 14a is square.

The resin molding is carried out in the same manner as in the above embodiment, by closing and opening the resin passage 24 by operating the gate runner pins 14a and 14b to project. The resin can be injected from the entire side edge of the cavity 12 in this manner because the resin of the gate portion can be removed by the gate runner pins 14a and 14b to perform resin molding. Further, according to such a method, there is a great advantage that the resin can be easily and surely molded even if the product is extremely thin such that the thickness of the package portion is about 0.5 mm or less. In this way, the method of filling the resin with the entire width of the cavity 12 has a problem that when the resin is filled with a gate whose width is narrower than the side edge width, air is likely to be trapped in a portion outside the gate width in the cavity. Can be eliminated and is effective.

In the conventional resin molding method, the gate is broken at the connecting portion between the package and the gate at the time of breaking the gate. Therefore, at that time, the depth of the gate is set to the cavity depth so that the main body of the package is not damaged. It is set to 1/2 or less. Therefore, in the case of a product having an extremely thin package, the gate becomes very narrow, which makes resin injection very difficult and imposes a large restriction on the characteristics of the resin used. When the resin is filled from the entire width of the cavity 12 as described above, the restriction of the resin injection at the gate portion can be effectively alleviated, and the resin can be easily filled into the cavity. Especially effective for products. In the embodiment, the resin path 24 is the molded product 1
6, the gate runner pin 14a provided on the upper and lower surfaces of the mold 6 acts to remove the resin from the side edge of the package to the side edge of the molded product 16, and the gate runner pin 14b provided on the lower mold side is The resin is eliminated only in the connecting portion with the package, and the cull is attached to the lower surface side of the molded product 16 and released.

In each of the above embodiments, the outer surface of the gate runner pin on the cavity side is aligned with the end surface of the cavity and forms the outer surface of the resin package. Therefore, the gate end surface of the gate runner pin is formed in a tapered shape in accordance with the package shape. In this case, resin flash may occur at the connection between the gate runner pin and the cavity. Therefore, as shown in FIG. 10, make the thickness of the tapered surface of the gate runner pin 14a, 14b slightly smaller than the package thickness. It is preferable that the corners of the tapered surface are rounded. The amount of thinning the tapered surface may be about 5 to 10% of the package thickness. By designing the gate runner pin in this way, it is possible to suppress the occurrence of resin burrs in resin molding using the gate runner pin and perform suitable resin molding.

As described above, the resin molding apparatus according to the present invention is characterized in that the resin molding is performed by using the gate runner pins. However, due to this constitution, the conventional resin molding apparatus cannot perform accurate resin molding. It can be suitably used for extremely thin products, and can also be suitably used for products that are affected by the gate break even on the product side. For example, in the case of a product in which a TAB tape is directly resin-molded, the product may be damaged when the gate is peeled off from the tape, but this device can eliminate the need for a gate break and damage the product. Can be eliminated. Thus, the resin mold device according to the present invention can be used in various ways according to the product.

[0030]

As described above, according to the resin molding apparatus and the method of controlling the same according to the present invention, since the gate runner pin is provided for resin molding,
Even a product having a thin package, which is almost impossible to mold with the conventional resin molding apparatus, can be surely resin-molded. Also,
The gate break is unnecessary by molding the resin without leaving the resin at the end of the gate connected to the resin package. Especially for the type that pushes the gate runner pin to the side edge of the molded product, it remains as it is in the mold open state. As a resin molded product, it is possible to eliminate the problem of damaging the molded product during a gate break. In addition, since it is possible to fill the molten resin with good quality, it is possible to obtain a highly reliable product.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of an embodiment of a resin molding device.

FIG. 2 is an explanatory diagram showing a planar arrangement of cavities, pots and the like in a mold of a resin molding device.

FIG. 3 is an explanatory view showing an operation of resin molding by a resin molding device.

FIG. 4 is an explanatory view showing an operation of resin molding by a resin molding device.

FIG. 5 is an explanatory view showing a product molded by resin using a resin molding device.

FIG. 6 is an explanatory diagram showing an example of a product molded by resin using a resin molding device.

FIG. 7 is an explanatory view showing an example of a product molded by resin using a resin molding device.

FIG. 8 is an explanatory view showing an example of a product molded by resin using a resin molding device.

FIG. 9 is an explanatory view showing another embodiment of the resin molding device.

FIG. 10 is an explanatory diagram showing another configuration example of the gate runner pin.

[Explanation of symbols]

 10 Pot 12 Cavities 14a, 14b Gate Runner Pin 16 Molded Product 18a Upper Chase 18b Lower Chase 20 Plunger 22a, 22b Air Cylinder 24 Resin Path 26 Resin Tablet 30 Resin Package 32 Cal

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[Procedure amendment]

[Submission date] January 24, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction content]

After filling the cavity 12 with resin at a low pressure,
Plunger 20 with high clamping force for upper and lower molds
Switch to holding pressure control that presses at high pressure. In the pressure-holding step, the resin is cured by applying pressure to the cavity 12, but when the viscosity of the resin rises to a certain extent at this time, FIG. 4 (b)
The gate runner pins 14a and 14b are attached to the air cylinders 22a and 2 until the end surface comes into contact with the molded product 16 as shown in FIG.
Push with 2b to make it protrude. In this operation, the gate runner pins 14a and 14b project while removing the resin in the resin passage 24, so that the resin runs in the gate runner pin 14
It is necessary to start before reaching the limit viscosity that can be excluded by a and 14b. In addition, this gate runner pin
The cavity 1 is used during the protrusion operation by 14a and 14b.
It is conceivable that resin shrink will start within 2.
Push-out operation with gate runner pins 14a, 14b
Acts to replenish the resin to the resin shrink.
To prevent warpage of molded products after resin curing.
Also has a use.

Claims (4)

[Claims] 1. A resin molding apparatus for connecting a pot and a cavity by a resin path and forcing a molten resin from the pot to the cavity through the resin path to perform resin molding, wherein a resin path at a gate end position of the cavity is provided. A gate runner pin whose end face that contacts the molded product is formed to be flat so that the resin path can be opened and closed so that it can be pushed in the mold opening and closing direction. To a position where the resin passage is opened, and after the cavity is filled with resin, a drive mechanism is provided to cause the gate runner pin to project to a position where the end face of the gate runner pin contacts the molded product. apparatus. 2. The resin molding apparatus according to claim 1, wherein the gate runner pin is arranged so as to face the upper mold and the lower mold with the article to be molded interposed therebetween. 3. The shape of the end face of the gate runner pin that abuts the molded product is pushed over the entire range from the gate end position of the cavity to the side edge portion of the molded product in accordance with the resin path arrangement on the molded product. The resin molding apparatus according to claim 1, wherein the resin molding apparatus is provided so as to be in contact with each other. 4. The control method for the resin molding device according to claim 1, 2 or 3, wherein the gate and the resin are closed by projecting the gate runner pin in a state where the resin is put into the pot to close the pot and the resin. The inside of the passage is closed and the resin is melted, and the resin is compressed by the plunger to discharge the mixed gas in the resin out of the mold, and then the gate runner pin is returned to the retracted position.
The resin passage is opened to fill the cavity with resin, and then the gate runner pin is extruded until the end surface of the gate runner pin contacts the molded product while separating the resin in the resin passage to separate the cavity side from the pot side. Then, the method of controlling the resin molding apparatus is characterized in that the mold is opened after the resin is cured and the molded product is taken out.