JP2001191338A - Sheet for cleaning mold and method for manufacturing semiconductor device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance productivity by enhancing the cleaning effect of a mold and shortening a cleaning time. SOLUTION: A cleaning sheet 29 has through-holes 29a formed therein at the place corresponding to the cavity of a mold and also has slits 29b or cut-in parts 29c for a flow cavity formed thereto at the corner parts of the outer peripheral parts of the through-holes 29a. This cleaning sheet is arranged between the first and second molds of the mold to be used at a time of the cleaning of the interior of the mold to enhance the cleaning effect of the mold.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing technique, and more particularly, to a technique effective when applied to a cleaning effect of a cleaning in a molding die for a semiconductor device and improvement of manufacturability.

[0002]

2. Description of the Related Art The technology described below studies the present invention,
Upon completion, they were examined by the inventor, and the outline is as follows.

In the resin sealing step of a resin-sealed semiconductor device, resin molding is repeated many times, so that the inside of a molding die filled with a sealing resin, that is, a pair of molding dies is formed. Dirt such as resin burrs, oil or dust accumulates around the cavities, runners, air vents and cul-blocks of the mold and lower mold.

[0004] Such dirt has an adverse effect on the molding quality and also reduces the releasability when the product is taken out of the molding die. Therefore, the operator removes the molding die every predetermined number of shots. Needs cleaning.

[0005] However, since cleaning of a molding die by an operator requires a considerable amount of time since it is a manual operation, a technique capable of cleaning the molding die in a short time is required.

In order to meet such a demand, a lead frame on which no semiconductor chip is mounted (hereinafter referred to as a dummy lead frame) is clamped on a molding die, and a cleaning resin is filled in the molding die. The method of cleaning a molding die is performed.

However, according to this technique, an expensive dummy lead frame is used for cleaning, which is not only uneconomical, but also requires a dummy lead frame of a specific shape suitable for the molding die. Therefore, precision is required for positioning the molding die and the dummy lead frame. In addition, the resin formed on the cull and runner portions of the molded cleaning resin separates from the lead frame and separates, and it takes a considerable amount of time to remove the separated resin from the molding die. Is bad.
Also, the separated culls and runners may get caught in the sliding portion of the molding apparatus, and as a result, may cause a failure.

Therefore, as a technique for solving such a problem, the following technique has been devised.

First, as a first technique, Japanese Patent Laid-Open Publication No.
As described in Japanese Patent No. 4866, a sheet-shaped member made of a cotton cloth (non-woven fabric) that can be impregnated and permeable with a cleaning resin is clamped between the opened molds, and the mold cavity is closed. And a step of filling the inside with a cleaning resin in a molten state.

Further, as a second technique, Japanese Patent Application Laid-Open No.
As described in Japanese Patent No. 5010, a substrate made of flame-retardant paper nonwoven fabric or resin having a hole at a position corresponding to a cavity is arranged between molding dies, and in this state, cleaning is performed in the mold. This is a method of filling and solidifying a cleaning resin to release the substrate and the cleaning resin.

[0011]

However, in the first technique, when the cleaning resin is filled in the cavity, the sheet-like member moves up and down (lifts) in the cavity, whereby the cleaning resin is removed. A phenomenon occurs in which the sheet-like member becomes resistant to the flow and the cleaning resin does not spread to every corner in the cavity.

As a result, there is a problem that dirt remains in the corners of the cavity and cleaning inside the cavity becomes insufficient.

In the second technique, a single substrate made of paper nonwoven fabric or resin covers not a whole mating surface of a molding die but a part of the mating surface (for example, half of one side). In addition, it is difficult to remove dirt attached to air vents and culls, and a plurality of substrates are used for one cleaning shot. As a result, post-processing such as removal of the substrate after cleaning is troublesome. .

Thus, there is a problem that the working time after cleaning is inefficient.

Here, the mating surface of the molding die has a flow cavity communicating with the corner of the outer periphery of the cavity. Recesses for improving the filling balance of the inner sealing resin) and air vents.

However, in the cleaning of the molding die using the molding die cleaning sheet, the cleaning resin does not easily flow around the corners of the cavity, and as a result, the cleaning resin enters the flow cavity and the air vent during cleaning. Therefore, the flow cavity and the air vent are not cleaned, so that there is a problem that the cavity is not sufficiently filled with the sealing resin when the cleaned product is molded.

Further, if the sealing resin does not easily flow around the corner of the cavity, the cleaning resin does not become entangled with the portion corresponding to the vicinity of the corner of the cavity of the molding die cleaning sheet. Even when the cleaning resin is removed from the mating surface of the molding die together with the cleaning resin for the molding die, the cleaning resin remains and it takes time to remove the molding die cleaning sheet and the cleaning resin from the mating surface. Is a problem.

Also, an SOP (Smal) having an elongated sealing portion
l Outline Package) and QF using matrix frame
When the distance between the outside edge of the cavity and the edge of the mating surface is relatively short (for example, 10 mm or less) on the mating surface of the mold for molding such as N (Quad Flat Non-leaded Package) When the molding die is cleaned, the cleaning resin leaked from the cavity protrudes from the molding die cleaning sheet and adheres to the side surface connected from the mating surface of the molding die.

In such a case, it takes time to remove the cleaning resin adhering to the side surface of the molding die.
As a result, there is a problem that the efficiency of the cleaning operation of the molding die is reduced.

An object of the present invention is to provide a molding die cleaning sheet for improving the productivity by improving the cleaning effect of the molding die and shortening the cleaning operation time, and a method of manufacturing a semiconductor device using the same. To provide.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0022]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, the sheet for cleaning a molding die according to the present invention is disposed between the first die and the second die of a pair of a first die and a second die. A molding die cleaning sheet for cleaning the inside of the molding die, and covers the entire mating surface of the molding die when disposed between the first die and the second die. And a through-hole corresponding to the cavity of the molding die.

With this, when supplying and filling the cavity with the cleaning resin, the cleaning resin can pass through the through hole of the molding die cleaning sheet without resistance, so that the filler or the resin contained in the cleaning resin is injected. Irrespective of the pressure, the cleaning resin can spread to every corner of the cavity without obstructing the flow of the cleaning resin in the cavity.

As a result, dirt at the corners of the cavity can be removed by the cleaning resin that has spread to the corners of the cavity. Therefore, the cavity of the molding die can be sufficiently cleaned, whereby the cleaning effect can be improved. The through-hole is particularly effective for manufacturing a product having a high injection pressure, a product having a small molded package, and a thin package.

Further, a method of manufacturing a semiconductor device according to the present invention
A step of preparing the molding die cleaning sheet that covers the entire mating surface of the molding die composed of a pair of the first die and the second die and has a through-hole corresponding to the cavity of the molding die. Disposing the molding die cleaning sheet on the entire mating surface of the molding die with the through-holes corresponding to the cavities, and disposing the molding die cleaning sheet on the first die and the second die. A step of clamping with a mold and a step of supplying a cleaning resin to the cavity, and passing the cleaning resin through the through-hole of the molding die cleaning sheet to fill the cavity with the cleaning resin. After the cleaning resin is solidified, the cleaning resin and the molding die cleaning sheet are separated from the molding die. And a step of.

Further, in the method of manufacturing a semiconductor device according to the present invention, a through hole corresponding to a cavity of the molding die covers an entire mating surface of the molding die composed of a pair of first and second dies. And a step of preparing the molding die cleaning sheet in which a notch portion corresponding to a concave portion provided in an outer peripheral portion thereof is formed in communication with the cavity, and the through hole corresponds to the cavity. The molding die cleaning sheet is disposed on the entire mating surface of the molding die with the notch portions corresponding to the recesses, and the molding die cleaning sheet is placed on the first die and the second die. Clamping with a mold, supplying a cleaning resin to the cavity, and applying the cleaning resin to the through-hole of the molding die cleaning sheet and the cleaning resin. A step of filling the cavity and the concave portion with the cleaning resin through an insertion portion, and after curing the cleaning resin, the cleaning resin and the molding die cleaning sheet are removed from the molding die. And releasing the mold.

Thus, when cleaning resin is injected into the cavity during cleaning of the molding die,
The cleaning resin can be passed through the cut portion of the molding die cleaning sheet.

Therefore, the cleaning resin can be filled in the concave portion such as the flow cavity or the air vent, and the cleaning resin can be entangled and adhered to the molding die cleaning sheet through the cutout portion.

As a result, after the cleaning resin is cured,
By peeling off the molding die cleaning sheet from the molding die, the cleaning resin filled in the concave portion is removed, so that the cleaning effect of the concave portion can be improved and the molding die cleaning sheet can be surely cleaned. The resin can be removed, whereby the cleaning resin can be easily removed from the concave portion.

Further, a method of manufacturing a semiconductor device according to the present invention
The molding die cleaning sheet, which covers the entire mating surface of the molding die composed of a pair of first and second dies and has a through-hole corresponding to the cavity of the molding die; A step of preparing a reinforcing sheet that can be arranged along the periphery of the mating surface outside the plurality of cavities of the mating surface of the mold; and forming the through-hole of the molding die cleaning sheet in the cavity. Correspondingly, the molding die cleaning sheet is arranged on the entire mating surface, and the reinforcing sheet is arranged on the mating surface outside the plurality of cavities along the peripheral edge of the mating surface. Clamping the mold cleaning sheet and the reinforcing sheet by the first mold and the second mold; and supplying a cleaning resin to the cavity. A step of passing the cleaning resin through the through-hole of the molding die cleaning sheet to fill the cavity with the cleaning resin; and after curing the cleaning resin, the cleaning resin and the Releasing the molding die cleaning sheet from the molding die.

Thus, the clamping force of the molding die can be improved, and as a result, leakage of the cleaning resin from the mating surface of the molding die during cleaning can be prevented. Therefore, it is possible to prevent the cleaning resin from adhering to the side surface of the molding die, so that there is no need to remove the cleaning resin. As a result, the efficiency of the cleaning operation of the molding die can be improved.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following embodiments, the description of the same or similar parts will not be repeated in principle unless particularly necessary.

Further, in the following embodiments, when necessary for the sake of convenience, the description will be made by dividing into a plurality of sections or embodiments, but they are not unrelated to each other unless otherwise specified. One has a relationship of some or all of the other, such as modified examples, details, and supplementary explanations.

In the following embodiments, when referring to the number of elements and the like (including the number, numerical value, amount, range, etc.), the number is particularly limited to a specific number and clearly limited to a specific number in principle. Except for cases, the number is not limited to the specific number, and may be greater than or less than the specific number.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all the drawings for describing the embodiments, members having the same functions are denoted by the same reference numerals, and the repeated description thereof will be omitted.

(Embodiment 1) FIG. 1 is a perspective view showing an example of the structure of a transfer molding apparatus for performing molding using a molding die cleaning sheet according to Embodiment 1 of the present invention, and FIG. FIG. 3 is a partial cross-sectional view showing a structure of a resin molding unit in the transfer mold apparatus shown in FIG. 3; FIG. 3 is a view showing an example of a structure of a molding die cleaning sheet according to Embodiment 1 of the present invention; 4B is a cross-sectional view taken along the line AA in FIG. 4A. FIG. 4 shows a cleaning sheet for a molding die on a mating surface of a second die of a molding die provided in the resin molding section shown in FIG. FIG. 5 is a plan view showing an example of an arrangement state, FIG. 5 is a partial cross-sectional view showing an example of a state at the time of cleaning in a molding die using the molding die cleaning sheet shown in FIG. 3, and FIG. 6 is a semiconductor of the present invention. Manufactured by the manufacturing method of the device And is a perspective view showing the one example in partial cross section of a structure of a semiconductor device.

The transfer molding apparatus shown in FIG. 1 is of a multi-pot type. For example, the semiconductor chip 24 shown in FIG. 6 and the inner leads 20 electrically connected to the semiconductor chip 24 are sealed with resin. Is what is used for

This transfer molding apparatus includes a first mold 3 as an upper mold, a second mold 4 as a pair of a lower mold, a first mold 3 and a second mold 4. A loader 1 for carrying a resin molding unit 5 provided, a work (here, for example, a lead frame that has been subjected to die bonding and wire bonding) into the resin molding unit 5, and an unloader 2 for removing the work from the resin molding unit 5 In the transfer molding apparatus, the lead frame to which the semiconductor chip 24 (see FIG. 6) is bonded is carried into the resin molding section 5 from the loader 1 shown in FIG. The semiconductor chip 24 and the like are sealed with resin. Note that a QFP (Quad Flat Package) 19, which is a resin-encapsulated semiconductor device whose resin molding has been completed, is carried out to the unloader 2 and housed therein.

Further, the resin molded portion 5 shown in FIG. 2 includes a cavity 6, a cull 7, a runner 8, a pot 9, a plunger 10 and a cavity 6 having a shape corresponding to the sealing portion 22 of the QFP 19 shown in FIG. , Ejector plates 11, 15, ejector pins 12, 16, gate 13, air vent 1
4 are provided.

Further, as shown in FIG.
In the mating surface 26 of the second mold 4 (see FIG. 2), cavities 6 of a predetermined shape in which the semiconductor chips 24 are arranged are formed at a plurality of locations (the cavities 6 are formed of the first mold 3). The mating surface 26 is also formed in the same manner as the second mold 4).

At a predetermined position of the second mold 4, a plurality of cylindrical pots 9 for setting a sealing resin such as a tablet are formed so as to penetrate therethrough, and the first mold corresponding to the pot 9 is formed. A cull 7 is provided in each of the portions 3 as shown in FIG.

Further, a plurality of runners 8 communicating with the plurality of cavities 6 are formed to branch from the cull 7 so that the first mold 3 and the second mold 4 are in close contact with each other. In this state, the upper side of the pot 9 is closed by the cull 7, and the pot 9 is connected to the plurality of cavities 6 via the cull 7 and the runner 8. An air vent 14 is formed outside the cavity 6 to allow the air in the cavity 6 to escape to the outside to completely fill the resin.

Next, the molding die cleaning sheet (hereinafter simply referred to as cleaning sheet) 17 of the first embodiment shown in FIG. 3 will be described.

The cleaning sheet 17 is disposed between the first die 3 and the second die 4 of the molding die 28 when the semiconductor chip 24 is not molded.
And cleans the entire mating surface (parting surface other than the cavity) 26 of the molding die 28 when disposed between the first die 3 and the second die 4. A through hole 17a corresponding to the cavity 6 of the molding die 28 is formed.

The through hole 17a formed in the cleaning sheet 17 according to the first embodiment has substantially the same shape as the opening 6a of the cavity 6 (see FIG. 2).

That is, the through-hole 17a is formed in a quadrangular shape that is substantially the same as or slightly smaller than the shape and size of the opening 6a of the cavity 6 of the first mold 3 and the second mold 4. .

Thus, at the time of cleaning, only the cleaning sheet 17 is clamped by the first mold 3 and the second mold 4 and the cleaning resin 25 shown in FIG. By
In the cavity 6, the cleaning resin 25 passes through the through hole 17a of the cleaning sheet 17, and as a result,
The cleaning resin 25 becomes a resistance in the cavity 6 and the cleaning sheet 17 is filled in every corner of the cavity 6 without lifting.

Therefore, the inside of the cavity 6 can be sufficiently cleaned.

As shown in FIG. 4, the cleaning sheet 17 of the first embodiment has a size that covers the entire mating surface 26 of the second mold 4 (the same applies to the first mold 3).
Of shape.

That is, it is formed in such a size that it can be guided by the positioning wefts 18 for positioning the upper and lower dies provided on each side of the outer periphery of the mating surface 26 of the second die 4. When the cleaning sheet 17 is placed on the mating surface 26 of the second mold 4, the cleaning sheet 17 may be placed in accordance with the positioning wedges 18 on each side. There is no need to perform high-precision positioning.

The cleaning sheet 17 according to the first embodiment has a heat resistance and flexibility of, for example, 100%.
% Of paper, cloth or non-woven fabric, and among them, it is preferable to be formed of non-woven fabric.

Further, the thickness of the cleaning sheet 17 is, for example, about 0.6 mm when the first mold 3 and the second mold 4 are clamped.

The QFP 19 shown in FIG. 6 is an example of a semiconductor device assembled by performing molding by the transfer molding device shown in FIG. 1. The QFP 19 includes electrodes of the semiconductor chip 24 and inner leads 20 corresponding to the electrodes. A bonding wire 21 to be electrically connected, a sealing portion 22 formed by resin-sealing the semiconductor chip 24, the inner lead 20 and the bonding wire 21, and a connection to the inner lead 20, and an external connection from the sealing portion 22. And a plurality of outer leads 23 which are external terminals protruding from each other, and each outer lead 23 is formed in a gull wing shape.

Next, a method of manufacturing the semiconductor device of the first embodiment will be described.

The method for manufacturing the semiconductor device is described in FIG.
And a step of cleaning the inside of a molding die 28 of the transfer molding apparatus using the cleaning sheet 17 shown in FIG. 3 and a step of molding (resin sealing) the semiconductor chip 24 using the transfer molding apparatus shown in FIG. It is.

First, in the wire bonding step,
The semiconductor chip 24 and the inner lead 20 of the lead frame, which is a work, are electrically connected by a bonding wire 21.

Thereafter, in a molding step, the semiconductor chip 2 is transferred using the transfer molding apparatus shown in FIG.
4 and the inner leads 20 electrically connected to the semiconductor chip 24 and the bonding wires 21 are resin-sealed with a sealing resin.

Here, the resin sealing (molding) step in the molding step of the first embodiment will be described.

First, on the plunger 10 shown in FIG.
A solid sealing resin (tablet) heated by a preheater is set, and then the lead frame in which the semiconductor chip 24 and the inner lead 20 are wire-bonded is transferred from the loader 1 shown in FIG. Transport.

In this state, the second mold 4 is moved toward the first mold 3 to move the cavity between the first mold 3 and the second mold 4 forming the molding mold 28. 6 is formed. Then, when the sealing resin in a molten state is pushed out to the cull 7 by the plunger 10,
The sealing resin flows into the cavity 6 through the runner 8 and the gate 13.

Further, the sealing resin filled in the cavity 6 is thermoset by heat and cure, and thereafter, when the second mold 4 is moved downward, the mold is opened.

Subsequently, the ejector plate 15 is moved down while the ejector plate 11 is moved up. As a result, the ejector pins 12 and 16 project to complete the mold opening, and the resin-sealed QF of the resin-sealed type is completed.
P (semiconductor device) 19 is taken out. In this resin sealing, since hundreds of shots are repeated a day, the inside of the molding die 28 filled with the sealing resin, that is, the molding die 2
Resin burrs and dirt (adhesion) such as oil and dust accumulate on the mating surface 26 (including the air vent 14 and the cavity 6 and the vicinity of the runner 8 and the cull 7) 26 of the first mold 3 and the second mold 4 of FIG. Will do.

Therefore, it is necessary to perform a cleaning step of the molding die 28 in the molding step in order to remove the dirt.

The lead frame is then cut in the cutting step for the QFP 19, thereby completing the assembly of the QFP 19 as shown in FIG.

Next, the cleaning step (a method of cleaning a molding die) of the first embodiment will be described.

First, the cleaning sheet 17 shown in FIG. 3 formed of a nonwoven fabric and covering the entire mating surface 26 of the molding die 28 and having the through holes 17a corresponding to the cavities 6 of the molding die 28 is prepared. prepare.

Subsequently, the mold temperature of the molding mold 28 is set to, for example, 170 ° C. to 180 ° C.

Thereafter, as shown in FIG.
Cleaning sheet 17 corresponding to cavity 6
Are arranged on the entire mating surface 26, and in this state, the second mold 4
Is moved toward the first mold 3.

By this approaching movement, the cleaning sheet 17 is clamped between the first mold 3 and the second mold 4, and then the cleaning resin 25 is supplied to the cavity 6.

At this time, as shown in FIG.
The cleaning resin 25 is passed through the through-holes 17a of the cleaning sheet 17 to fill the inside of the cavity 6 with the cleaning resin 25.

Subsequently, the cleaning resin 25 is cured, and then the second mold 4 is moved downward, whereby
The mold is opened by separating the first mold 3 and the second mold 4 from each other.

Further, the ejector plate 15 is moved downward while the ejector plate 11 is moved upward. As a result, the ejector pins 12, 16 project to complete the mold opening.

Thereafter, the cleaning resin 25 and the cleaning sheet 17 are released from the molding die 28.

That is, the cleaning sheet 17 and the cleaning resin 25 molded on the sheet are taken out.

Thus, the inside of the molding die 28 is cleaned.

The cleaning sheet 1 shown in FIG.
After the inside of the molding die 28 is cleaned using the mold 7, when starting (molding) again, the semiconductor chip 24 is arranged in the cavity 6 of the molding die 28, and thereafter, by the same method as the above-described molding method. Then, a sealing resin is supplied to the cavity 6 to seal the semiconductor chip 24 with the resin.

According to the molding die cleaning sheet and the method of manufacturing a semiconductor device using the same according to the first embodiment, the following operational effects can be obtained.

That is, the cleaning sheet 17
Since the through-holes 17a corresponding to the cavities 6 are formed, the cleaning resin 25 can pass through the through-holes 17a of the cleaning sheet 17 when the cavity 6 is supplied with and filled with the cleaning resin 25. Irrespective of the filler or resin injection pressure contained in the cleaning resin 25, the cleaning resin 25 can be spread to every corner of the cavity 6 without obstructing the flow of the cleaning resin 25 in the cavity 6.

As a result, dirt at the corners of the cavity 6 can be removed by the cleaning resin 25 that has spread to all corners of the cavity 6.

Thus, the cavity 6 of the molding die 28
Cleaning can be performed satisfactorily,
The cleaning effect can be improved.

The cleaning sheet 17 covers the entire mating surface 26 of the molding die 28 during cleaning, so that the cleaning sheet 17 formed by the cavity 6, the mating surface 26 (parting surface), the cull 7 and the gate 13 is formed. Since the resin 25 is connected by the cleaning sheet 17, when the cleaning sheet 17 is taken out after the cleaning resin 25 is hardened, the resin 25 is taken out in an integrated state without being separated on the cleaning sheet 17. Can be.

Therefore, the cleaning sheet 17 can be easily attached to and detached from the molding die 28, whereby the cleaning sheet 17 after the cleaning can be easily processed.

As a result, the time for the cleaning operation using the cleaning sheet 17 can be reduced.

Further, since the cleaning sheet 17 covers the entire mating surface 26 of the molding die 28, the cleaning resin 25 is also cleaned at the inlet 9 of the molding die 28, around the cull 7, and also at the air vent 14. The dirt can be removed by entanglement with the sheet 17, and as a result, resin burrs can be removed, and the working time can be greatly reduced.

Further, since the cleaning sheet 17 covers the entire mating surface 26 of the molding die 28, it is possible to clean a portion of the molding die 28 where the cleaning resin 25 does not contact.

The cleaning sheet 1 is not limited to the number of lead frames and the like set in the molding die 28.
Since the whole of the mating surface 26 of the molding die 28 is covered by the sheet, it is not necessary to position the cleaning sheet 17 with respect to the molding die 28 with high accuracy.

At this time, by using the cleaning sheet 17 made of a non-woven fabric as in the first embodiment, the molding die 28 as in the case of using a conventional dummy lead frame is used. The processing of the positioning pin and the processing of the positioning pin hole are not required.

Therefore, the cost of the molding die 28 can be reduced.

Further, since the dummy lead frame is not used, no misalignment due to the misalignment of the dummy lead frame occurs.

Further, since the entire mating surface 26 of the molding die 28 is covered by one cleaning sheet, the cleaning sheet 17 is not limited to the number of lead frames set in the molding die 28 at the time of molding. What is necessary is just to set, and as a result, cost reduction of a cleaning operation can be achieved.

By using the cleaning sheet 17 of the first embodiment, it is not necessary to use an expensive dummy lead frame for cleaning, so that the cost of the cleaning operation of the molding die 28 can be reduced. Can be.

The cleaning sheet 17 has a through hole 17a corresponding to the opening 6a of the cavity 6,
In addition, by covering the entire mating surface 26 of the molding die 28 during cleaning, the cleaning effect can be improved without lowering the cleaning workability.

In the process of manufacturing the semiconductor device such as the QFP 19 of the first embodiment, the time required for the cleaning operation of the molding die 28 can be greatly reduced, and the effect of cleaning the molding die 28 can be improved. With this, the manufacturability of the semiconductor device can be improved.

(Embodiment 2) FIG. 7 is a plan view showing an example of the structure of a molding die cleaning sheet according to Embodiment 2 of the present invention, and FIG. 8 is a plan view of the molding die cleaning sheet shown in FIG. FIG. 9 is an enlarged partial plan view showing an example of a state of being disposed on a mating surface of a mold, and FIG. 9 is a plan view showing a structure of a molding die cleaning sheet of a modified example of the molding die cleaning sheet shown in FIG.

In the second embodiment, a modified example of the molding die cleaning sheet used in the cleaning step of the molding die 28 shown in FIG. 2 in the semiconductor device manufacturing process described in the first embodiment will be described.

That is, the cleaning sheet (molding sheet cleaning sheet) 29 shown in FIG. 7 is located at a position corresponding to the cavity 6 of the molding die 28 similarly to the cleaning sheet 17 described in the first embodiment. Through hole 2
9a is formed, and in addition to this,
A cut portion such as a slit 29b and a cut portion 29c for a flow cabinet is formed at a corner of the outer peripheral portion of 9a.

The through-hole 29a is substantially the same size as the cavity 6 of the molding die 28, or slightly smaller than that.

Further, as shown in FIG. 8, the slit 29b and the cut portion 29c for the flow cabinet
Are formed at locations corresponding to the flow cavities 27 (concave portions) communicating with the cavities 6. Of these, the cut portions 29 c for the flow cavities are cut portions formed to have substantially the same shape as the flow cavity 27. is there.

Here, the flow cavity 27 allows the air and the sealing resin in the cavity 6 at the time of the injection of the resin to escape therethrough, thereby taking in air from the gate 13 and filling the sealing resin in the cavity 6. Is to improve.

Therefore, the slit 29b and the cutout portion 29c for the flow cabinet are used to clean the molding resin 28 with respect to the flow cavity 27 and the air vent 14 which are concave portions communicating with the cavity 6, and the cleaning resin 25 shown in FIG. For sufficient filling.

That is, when the cleaning resin 25 is injected into the cavity 6, the cleaning resin 25 is filled into the cavity 6 through the through holes 29a of the cleaning sheet 29. Further, the cleaning resin 25 is formed at the corners of the cavity 6. 25 is the cleaning sheet 2
9 for flow cabinet cut-out 29c and slit 29b
And flows into the flow cavity 27 and the air vent 14.

Thereby, the cut portion 2 for the flow cabinet is formed.
9c and the cleaning resin 25 through the slit 29b.
Can be entangled with the cleaning sheet 29, and the cleaning resin 25 can be filled in the flow cavity 27 and the air vent 14 in this state.

As a result, the removal of the cleaning resin 25 from the second mold 4 after the curing of the cleaning resin 25 can be performed together with the removal of the cleaning sheet 29 from the molding die 28.

The slits 29b may be formed as the cuts or the flow cabinet cuts 29c may be formed.
Is formed, since the cleaning resin 25 is relatively hard to flow into the flow cavity 27 located far from the gate 13 of the second mold 4, not the slit 29b but the flow cavity cutout 29c is formed. Is preferred.

The flow cavity 2 on the gate 13 side
Since the cleaning resin 25 relatively easily flows into 7, a slit 29b is formed here.

Therefore, in the modified example shown in FIGS. 7 and 8 (the cleaning sheet 29 for the QFP 19 shown in FIG. 6), only the flow cavity 27 disposed farthest from the gate 13 is cut by the cut portion 29c for the flow cabinet. The other three corners are slits 29b.

On the other hand, a modification (BGA) shown in FIG.
(Cleaning sheet 29 for (Ball Grid Array))
Shows a case where slits 29b are formed at four corners, and it is not particularly limited to which corner of the cavity 6 the notch 29c for the flow cabinet (see FIG. 7) and the slit 29b are formed. Also, the slit 29
b width or length or notch 29c for flow cabinet
Is not particularly limited.

The material and thickness of the cleaning sheet 29 of the second embodiment are the same as those of the cleaning sheet 17 of the first embodiment.

Further, the other structure of the cleaning sheet 29 according to the second embodiment and a method of manufacturing a semiconductor device using the cleaning sheet 29 will be described with reference to the semiconductor using the cleaning sheet 17 described in the first embodiment. Since the method is the same as the method of manufacturing the device, the description thereof will not be repeated.

The cleaning sheet 2 of the second embodiment
9 and a method for manufacturing a semiconductor device using the same,
When the cleaning resin 25 is injected into the cavity 6 at the time of cleaning the molding die 28 shown in FIG. 2, the cleaning resin 25 is passed through slits 29b of the cleaning sheet 29 and cut portions such as cut portions 29c for flow cabinets. be able to.

Thus, at the time of cleaning, concave portions such as the flow cavity 27 and the air vent 14 can be filled with the cleaning resin 25, and the cleaning resin 25 can be entangled and adhered to the cleaning sheet 29 through the cutout portion. it can.

Therefore, after the cleaning resin 25 is hardened, the cleaning sheet 29 is peeled off from the second mold 4 so that the recesses (flow cavities 27 and air vents 14) of the mating surface 26 of the second mold 4 are formed. Since the filled cleaning resin 25 is removed, the cleaning effect of the concave portion can be improved, and the cleaning resin 25 can be reliably removed together with the cleaning sheet 29. Therefore, the cleaning resin 25 can be removed from the concave portion. Can be easily performed.

As a result, the cleaning time of the molding die 28 using the cleaning sheet 29 can be reduced.

The notch 29c for the flow cabinet and the slit 2 corresponding to the recess at the portion of the second mold 4 facing the gate 13 (the portion relatively far from the gate 13).
By forming the cut portion such as 9b into a shape corresponding to the concave portion, the cleaning effect of the concave portion can be further improved.

(Embodiment 3) FIGS. 10A and 10B are views showing an example of the structure of a molding die cleaning sheet according to Embodiment 3 of the present invention, wherein FIG. 10A is a plan view and FIG. B-
FIG. 11 is a cross-sectional view taken along the line B, FIG. 11 is a plan view showing an example of a state in which the molding die cleaning sheet shown in FIG. 10 is arranged on the mating surface of the molding die, and FIG. It is an expanded partial sectional view.

In the third embodiment, similarly to the second embodiment, the molding die cleaning sheet used in the cleaning step of the molding die 28 shown in FIG. 2 in the manufacturing process of the semiconductor device described in the first embodiment. A modified example will be described.

That is, the framed cleaning sheet (molding die cleaning sheet) 30 shown in FIG.
The cleaning sheet 17 described in the first embodiment.
Similarly to the above, the cleaning sheet 30a which covers the entire mating surface 26 of the molding die 28 and has a through hole 30b formed at a location corresponding to the cavity 6, and the plurality of cavities 6 of the mating surface 26 of the molding die 28 Outer mating surface 2
6 and a frame-shaped reinforcing sheet 30c that can be arranged along the peripheral edge portion 26a.

The through-hole 30b formed in the cleaning sheet 30a is substantially the same size as the cavity 6 of the molding die 28 or slightly smaller than the cavity.

Here, as shown in FIG. 12, the cleaning sheet 30 with a frame according to the third embodiment is formed with a molding die 28.
When the cleaning resin 25 (see FIG. 5) is injected at the time of cleaning, the molding die 28 is clamped by the second die 4 as the lower die and the first die 3 as the upper die. The clamping force outside the cavity 6 is increased to prevent the cleaning resin 25 from leaking from the mating surface 26 of the molding die 28.

That is, as shown in FIG. 10, the framed cleaning sheet 30 is provided in the cavity 6 shown in FIG.
And a frame-like reinforcement that can be arranged along the peripheral edge 26a of the mating surface 26 outside the plurality of cavities 6 of the mating surface 26 of the second mold 4 in accordance with the above. The sheet 30c is attached.

As a result, when cleaning the molding die 28, as shown in FIG. 11, the cleaning sheet 30a is formed over the entire mating surface 26 with the through holes 30b of the cleaning sheet 30a corresponding to the cavities 6. The frame-shaped reinforcing sheet 30c is arranged on the mating surface 26 along the peripheral edge 26a of the mating surface 26 outside the plurality of cavities 6.

The cleaning sheet 30 with a frame according to the third embodiment has a cleaning sheet 30a and a reinforcing sheet 30c as shown in FIG. , The framed cleaning sheet 30 is arranged on the mating surface 26 of the second mold 4.

Thereafter, as shown in FIG. 12, the cleaning sheet 30a and the reinforcing sheet
5 and the second mold 4, and further, the cleaning resin 25 is injected into the cavity 6 in the clamped state as shown in FIG. 5 to fill the cavity 6 with the cleaning resin 25. After curing the mold 25, the mold resin 28 is cleaned by removing the cleaning resin 25 together with the cleaning sheet 30a from the mating surface 26 of the mold 28.

The cleaning sheet 30 with a frame shown in FIG. 10 is, for example, a comparatively elongated sealing portion 22 (see FIG. 6, except for the QFP1 shown in FIG. 6) in a semiconductor device.
9 is an SOP having a sealing portion 22 that is substantially square).
When molding a semiconductor device such as a QFN or a matrix frame using a matrix frame, the outer end of the cavity 6 and the mating surface 2
In the case where the distance (L shown in FIGS. 11 and 12) from the peripheral portion 26a of the molding die 6 is relatively short (for example, when L is 10 mm or less), the cleaning mold leaked from the cavity 6 when the molding die 28 is cleaned. Since the resin 25 may protrude from the molding die cleaning sheet and adhere to the side surface connected to the mating surface 26 of the molding die 28, the SOP or QFN having the L of 10 mm or less may be used.
It is more effective for cleaning the molding die 28 for use.

Here, the frame-shaped reinforcing sheet 30c has a thickness of, for example, about 0.1 to 0.2 mm, and is preferably formed of nonwoven fabric, paper, copper, fluororesin, or the like.

Further, like the cleaning sheet 30 with a frame according to the third embodiment, the cleaning sheet 30
a and the reinforcing sheet 30c may be attached in advance, or both may be prepared without being attached, and the cleaning may be performed by sequentially disposing them on the mating surface 26 of the molding die 28 during cleaning. .

The cleaning sheet 30 with a frame according to the third embodiment is also effective for a semiconductor device using a matrix frame other than SOP and QFN, or a BGA using a tape substrate.

The material and thickness of the cleaning sheet 30a in the framed cleaning sheet 30 of the third embodiment are the same as those of the cleaning sheet 17 of the first embodiment.

Further, a method of manufacturing a semiconductor device using the framed cleaning sheet 30 of the third embodiment will be described with reference to the cleaning sheet 1 described in the first embodiment.
7 is the same as the method of manufacturing the semiconductor device using No. 7, and the overlapping description is omitted.

According to the framed cleaning sheet 30 and the method of manufacturing a semiconductor device using the same according to the third embodiment, when the molding die 28 is cleaned, the cleaning sheet 30a of the framed cleaning sheet 30 penetrates. The holes 30b are arranged on the entire mating surface 26 so as to correspond to the cavities 6, and the reinforcing sheet 30c is arranged on the mating surface 26 along the peripheral edge 26a of the mating surface 26 outside the plurality of cavities 6, so that cleaning with a frame is performed. The clamping force of the molding die 28 can be improved by clamping the cleaning sheet 30 with the first die 3 and the second die 4 of the molding die 28, and as a result, the cleaning Leakage of the resin 25 from the mating surface 26 of the molding die 28 can be prevented.

Therefore, since the cleaning resin 25 can be prevented from adhering to the side surface of the molding die 28, there is no need to remove it, and as a result, the efficiency of the cleaning operation of the molding die 28 can be improved.

By using the framed cleaning sheet 30 to which the reinforcing sheet 30c is attached,
Mold 2 for cleaning resin 25 during cleaning
8 can be prevented from leaking out from the mating surface 26, so that the cleaning resin 25 can be sufficiently filled in the cavity 6 and the concave portion such as the cutout portion 29c for the flow cabinet (see FIG. 8). The cleaning effect of the concave portion such as the cut portion 29c for the flow cabinet can be improved.

In particular, when the distance between the outer end of the cavity 6 in the molding die 28 and the peripheral edge 26a of the mating surface 26 is relatively short (for example, when the distance L shown in FIG.
In the case of 0 mm or less), the framed cleaning sheet 30 having the reinforcing sheet 30c is particularly effective.

Further, by using the framed cleaning sheet 30 having the reinforcing sheet 30c, the leakage of the cleaning resin 25 from the mating surface 26 of the molding die 28 during cleaning can be prevented. Cleaning sheet 3 with frame for mating surface 26
0 can be easily attached and detached.

Further, when the cleaning sheet 30a is a non-woven fabric, the use of the reinforcing sheet 30c can prevent the expansion and contraction of the cleaning sheet 30a. As a result, the efficiency of the cleaning operation of the molding die 28 can be reduced. It can be further improved.

The invention made by the inventor has been specifically described based on the embodiments of the present invention. However, the present invention is not limited to the embodiments of the invention, and does not depart from the gist of the invention. It is needless to say that various changes can be made.

For example, in the first, second, and third embodiments, the case where the cleaning sheets 17, 29, and 30a are formed of a nonwoven fabric has been described. However, the material of the cleaning sheets 17, 29, and 30a is as follows. The material is not limited to the nonwoven fabric, but may be other materials such as paper and other cloth.

The cleaning sheets 17, 29,
The thickness of 30a is not limited to those described in the first, second, and third embodiments, and various thicknesses can be used.

Further, the cleaning sheets 17 and 2
Regarding the size of 9, 30a, it may be slightly smaller than the mating surface 26 as long as it covers almost the entire mating surface 26 of the molding die 28.

The cleaning sheets 17, 29,
Regarding the through holes 17a, 29a, and 30b formed in 30a, the shapes and the number of the through holes 17a, 29a, and 30b are determined according to the first, second, and third embodiments.
The shape is not limited to three, but may be various shapes and numbers. Further, the size is almost the same as that of the opening 6a of the cavity 6, or is large enough to allow the cleaning resin 25 to pass therethrough. If so, it may be larger or smaller than the opening 6a of the cavity 6.

In the molding dies 28 of the first, second and third embodiments, the lead frame may be a multiple-row single-row type, or may be a matrix frame.
In any case, the cost of the cleaning operation can be reduced.

In the first and second embodiments,
Although the case where the semiconductor device molded by the transfer molding apparatus shown in FIG. 1 is the QFP 19 shown in FIG. 6 is described, the semiconductor device is not limited to the QFP 19, and the semiconductor molded by the transfer molding apparatus and assembled. If it is a device, SO
Other semiconductor devices such as P may be used.

Further, in the molding dies 28 of the first, second and third embodiments, the first and second dies 3 and 4 have been described as the upper and lower dies. The first mold 3 may be a lower mold and the second mold 4 may be an upper mold.

[0145]

Advantageous effects obtained by typical ones of the inventions disclosed in the present application will be briefly described.
It is as follows.

(1). Since the through holes corresponding to the cavities are formed in the molding die cleaning sheet, the cleaning resin can pass through the through holes when supplying and filling the cavity with the cleaning resin. The cleaning resin can be spread to every corner of the cavity without obstructing the flow of the cleaning resin. As a result, dirt at the corners of the cavity can be removed. As a result, the cavity of the molding die can be sufficiently cleaned, and thus the cleaning effect can be improved.

(2). Since the molding die cleaning sheet covers the entire mating surface of the molding die, the cleaning resin formed by the cavity, the mating surface, the cull and the gate is in a state of being connected by the molding die cleaning sheet. It can be taken out in an integrated state without falling apart on the mold cleaning sheet. Therefore, the processing of the mold cleaning sheet after cleaning can be easily performed. As a result, the time required for the cleaning operation can be significantly reduced.

(3). Not only the number of lead frames set in the molding die, but also the entirety of the mating surface of the molding die with one molding die cleaning sheet, the height of the molding die cleaning sheet relative to the molding die is high. Accurate positioning is not required. As a result, there is no need to process the positioning pins or the positioning pin holes on the molding die, and thus the cost of the molding die can be reduced. In addition, since the dummy lead frame is not used, misalignment due to the misalignment of the dummy lead frame does not occur.

(4). By using the molding die cleaning sheet, it is not necessary to use an expensive dummy lead frame for cleaning, so that the cost of the molding die cleaning operation can be reduced.

(5). In the manufacturing process of the semiconductor device, the time for cleaning the molding die can be greatly reduced, and the effect of cleaning the molding die can be improved, so that the productivity of the semiconductor device can be improved.

(6). By cleaning the molding die using a molding die cleaning sheet provided with cutouts corresponding to the concave portion communicating with the cavity of the molding die, the cleaning cavity is used for cleaning the concave portion such as the flow cavity or air vent. Can be filled with resin,
Further, the cleaning resin can be entangled and adhered to the molding die cleaning sheet via the cutout portion. Therefore, after the resin is cured, the cleaning resin filled in the concave portions is removed by peeling the cleaning sheet from the molding die, thereby improving the effect of cleaning the concave portions.

(7). By using the reinforcing sheet together with the molding die cleaning sheet, it is possible to prevent the cleaning resin from leaking from the mating surface of the molding die at the time of cleaning, and therefore, it is possible to sufficiently fill the cavity and the concave portion with the cleaning resin. As a result, the effect of cleaning the cavity and the concave portion can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of the structure of a transfer molding apparatus for performing molding using a molding die cleaning sheet according to Embodiment 1 of the present invention.

FIG. 2 is a partial cross-sectional view showing a structure of a resin molding unit in the transfer molding device shown in FIG.

FIGS. 3A and 3B are diagrams showing an example of the structure of a molding die cleaning sheet according to the first embodiment of the present invention;
(A) is a plan view, and (b) is a cross-sectional view along the line AA of (a).

FIG. 4 is a plan view showing an example of a state in which a molding die cleaning sheet is arranged on a mating surface of a second die of a molding die provided in the resin molding section shown in FIG.

5 is a partial cross-sectional view showing an example of a state at the time of cleaning in a molding die using the molding die cleaning sheet shown in FIG. 3;

FIG. 6 is a perspective view showing, in partial cross section, an example of the structure of a semiconductor device manufactured by the method for manufacturing a semiconductor device of the present invention.

FIG. 7 is a plan view showing an example of the structure of a molding die cleaning sheet according to Embodiment 2 of the present invention.

8 is an enlarged partial plan view showing an example of a state where the molding die cleaning sheet shown in FIG. 7 is arranged on a mating surface of the molding die.

FIG. 9 is a plan view showing a structure of a molding die cleaning sheet according to a modification of the molding die cleaning sheet shown in FIG. 7;

FIGS. 10A and 10B are diagrams showing an example of the structure of a molding die cleaning sheet according to the third embodiment of the present invention, wherein FIG. 10A is a plan view and FIG. It is sectional drawing which follows the BB line of FIG.

11 is a plan view showing an example of a state in which the molding die cleaning sheet shown in FIG. 10 is arranged on a mating surface of the molding die.

FIG. 12 is an enlarged partial sectional view taken along the line CC shown in FIG. 11;

DESCRIPTION OF SYMBOLS 1 Loader 2 Unloader 3 First mold 4 Second mold 5 Resin molding section 6 Cavity 6a Opening 7 Cal 8 Runner 9 Pot 10 Plunger 11,15 Ejector plate 12,16 Ejector pin 13 Gate 14 Air vent (Concave part) 17 Cleaning sheet (molding sheet cleaning sheet) 17a Through hole 18 Positioning wet 19 QFP (semiconductor device) 20 Inner lead 21 Bonding wire 22 Sealing part 23 Outer lead 24 Semiconductor chip 25 Cleaning resin 26 Fitting surface 26a Peripheral edge 27 Flow cavity (recess) 28 Mold 29 Cleaning sheet (mold cleaning sheet) 29a Through hole 29b Slit (cut) 29c Cut for flow cabinet (cut) ) 30 framed cleaning sheet (molding die cleaning sheet) 30a cleaning sheet 30b through holes 30c reinforcing sheet

Claims (5)

[Claims] 1. A molding die comprising a pair of a first die and a second die, which is disposed between the first die and the second die to clean the inside of the die. A molding die cleaning sheet that covers an entire mating surface of the molding die when disposed between the first die and the second die, and corresponds to a cavity of the molding die. A sheet for cleaning a molding die, wherein a through hole is formed. 2. A method of manufacturing a semiconductor device using a molding die cleaning sheet, wherein the molding die covers an entire mating surface of a pair of a first die and a second die. Preparing the molding die cleaning sheet in which a through hole corresponding to a cavity of a mold is formed; and aligning the molding die cleaning sheet with the molding die by making the through hole correspond to the cavity. Clamping the molding die cleaning sheet by the first die and the second die by disposing the cleaning die sheet on the entire surface; supplying a cleaning resin to the cavity; Filling the cavity with the cleaning resin through the through hole of the mold cleaning sheet; and after curing the cleaning resin. The method of manufacturing a semiconductor device characterized by a step of releasing the cleaning resin and the molding die cleaning sheet from the molding die. 3. A method for manufacturing a semiconductor device using a molding die cleaning sheet, wherein the molding die covers an entire mating surface of a pair of a first die and a second die. Preparing the molding die cleaning sheet having a through-hole corresponding to the cavity of the die; and disposing the molding die cleaning sheet over the entire mating surface with the through-hole corresponding to the cavity. Clamping the molding die cleaning sheet with the first die and the second die, supplying a cleaning resin to the cavity, and applying the cleaning resin to the molding die cleaning sheet. Filling the cavity with the cleaning resin through the through-hole; and curing the cleaning resin, Removing the molding resin and the molding die cleaning sheet from the molding die; and cleaning the interior of the molding die using the molding die cleaning sheet, and then removing the cavity of the molding die. A semiconductor chip is disposed in the cavity, and thereafter, a sealing resin is supplied to the cavity to seal the semiconductor chip with the resin. 4. A method of manufacturing a semiconductor device using a molding die cleaning sheet, wherein the molding die covers an entire mating surface of a pair of a first die and a second die. A step of preparing the molding die cleaning sheet in which a through-hole corresponding to a cavity of a mold and a cutout corresponding to a concave portion provided in an outer peripheral portion of the cavity are formed in communication with the cavity; A hole is made to correspond to the cavity, and the notch is made to correspond to the concave portion, and the molding die cleaning sheet is arranged over the entire mating surface of the molding die, and the molding die cleaning sheet is 1
A step of clamping with a mold and the second mold, supplying a cleaning resin to the cavity, and passing the cleaning resin through the through-hole and the cutout portion of the molding die cleaning sheet; And a step of filling the concave portion with the cleaning resin, and a step of releasing the cleaning resin and the molding die cleaning sheet from the molding die after curing the cleaning resin. A method for manufacturing a semiconductor device, comprising: 5. A method of manufacturing a semiconductor device using a molding die cleaning sheet, wherein the molding die covers an entire mating surface of a pair of a first die and a second die. A mold cleaning sheet having a through-hole corresponding to a cavity of the mold, and a reinforcement that can be arranged along a peripheral edge of the mating surface outside the plurality of cavities of the mating surface of the mold. Preparing a sheet, and disposing the molding die cleaning sheet over the entire mating surface with the through-holes of the molding die cleaning sheet corresponding to the cavities; The molding die cleaning sheet and the reinforcing sheet are disposed on the mating surface along the periphery of the mating surface outside the cavity, and the first mold is provided with the reinforcing sheet. A step of clamping with the second mold, supplying a cleaning resin to the cavity, filling the cavity with the cleaning resin by passing the cleaning resin through the through hole of the molding die cleaning sheet. And a step of releasing the cleaning resin and the molding die cleaning sheet from the molding die after curing the cleaning resin.