JPH08306719A - Method and apparatus for resin sealing semiconductor device - Google Patents

Abstract

PURPOSE: To provide die for resin sealing a semiconductor device and a production method in which the resin can be left surely at upper and lower resin sumps while eliminating the gate break step. CONSTITUTION: Upper and lower dies comprises a cavity 17, an air vent 18, gate drawing parts 15, 16a having a drawing angle for molding a resin sump, a runner part 11, and a transfer pot 8. The lower die 2a is provided with a shutter 22a for removing the resin in the runner by moving up and down. The shutter 22a is disposed within a range covering the end part of a lead frame 7a and the starting point of gate drawing angle. More specifically, the shutter 22a is disposed such that the resin sump 12 of lower die 2a is left surely. Since the lead frame mounting a semiconductor chip is held between the dies and clamped, a semiconductor package can be molded without requiring any gate break.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin encapsulation method and a resin encapsulation apparatus for a semiconductor device, and more particularly to a resin encapsulation apparatus and a resin encapsulation method in which a shutter is provided in a runner portion to improve a gate break. .

[0002]

2. Description of the Related Art In recent years, semiconductor devices have been improved in the degree of integration with the progress of fine processing technology, and have been used in a wide range of fields including industrial equipment and consumer equipment. It was Therefore, a semiconductor device including a package having a shape that is easy to use for each device such as miniaturization, thinning, and multi-pinning has been commercialized.

Among the package forms used for these semiconductor devices, resin-sealed DIP (dual in
-Line package) type, QFP (quad)
flat package) type and QUIIP (qu
ad in-line) type.

When constructing these packages,
A lead frame using a conductive metal material is used,
A semiconductor chip is mounted on the island of this lead frame, and the electrode and the inner lead arranged around the island are wire-bonded by using a fine metal wire (wire) to make electrical connection, and these are sealed with resin. The structure to stop is adopted.

At the time of resin sealing as described above, a lead frame having a semiconductor device mounted therein is sandwiched in a cavity between an upper mold and a lower mold formed in conformity with a predetermined package shape, and the mold is clamped. Then, the resin is sealed from one side of the hanging pin of the island on which the semiconductor device is mounted. In that case, a hole portion called a resin inflow hole is formed in a region including the hanging pin portion and the corner portion in one of the methods developed to uniformly fill the resin on the upper and lower surfaces of the lead frame,
It is devised that the resin injected from a resin flow path called a runner portion on the lower surface side of the hanging pin also flows into the upper surface side through the resin inflow hole, and the resin is evenly injected into the upper and lower surfaces.

At this time, in order to equalize the resin flow through the runner portion on the lower surface side and the resin inflow hole, a predetermined narrowing angle is provided at the boundary between the runner portion and the cavity portion of the upper and lower molds and the upper gate and A protrusion called a lower gate and a space for resin flow adjustment called an upper resin reservoir are provided in front of the upper gate. Furthermore, a second-stage gate is provided between the lower gate and the lower runner portion, and the space between these gates is called the lower resin reservoir portion.

[0007] As an example thereof, it is a cross-sectional view of the die and the lead frame cut diagonally on the hanging pins in the step of resin-sealing the lead frame on which the semiconductor chip is mounted. FIG. 4 (a) showing a cross-sectional view of the frame, FIG. 4 (b) showing a cross-sectional view of a state where the upper mold and the lower mold are clamped before the start of encapsulation.
FIG. 4C is a cross-sectional view showing the resin-filled state, FIG. 4D is a cross-sectional view showing the resin-filled state, and FIG. 4D shows the packaged state after the package is separated from the mold by ejector pins. Referring also to FIG. 4 (e) shown in the cross-sectional view, the semiconductor chip 5 is mounted on the island 4 by using at least the silver paste 3 on the upper mold 1b and the lower mold 2b which are heated to a desired temperature in advance. The lead frame 7a is fixed and the electrode (not shown) formed on the semiconductor chip 5 and the inner lead are bonded via the bonding wire 6 (FIG. 4A).

Next, the resin tablet 9 is put into the transfer pot 8, the lower die 2b is pushed up, and the die is clamped while the lead frame 7a is held (FIG. 4).
(B)).

Next, after the resin tablet 9 is softened by the heat of the lower mold 2b and the plunger 10 for pressing the tablet rises, the resin flows through the runner portion 11 and passes through the lower second stage gate 20. First, it flows into the lower resin reservoir 12 and then into the upper resin reservoir 14 through the resin inflow holes 13 provided in the lead frame 7a.

The resin that has flowed into the resin reservoirs 12 and 14 flows toward the upper gate 15 and the lower gate 16a. The resin that has passed through the upper gate 15 and the lower gate 16a fills the inside of the cavity 17 while evacuating the air inside the cavity 17 from the air vent 18 before sealing.
The sealing is completed (FIG. 4 (c)).

Thereafter, the mold is held in a clamped state until the resin is completely cured (FIG. 4 (d)), and the lower mold 2b on the working side is opened after the resin is cured, and the ejector pin 19 is projected and sealed. The finished package is released from the mold (Fig. 4
(E)).

Remove the sealed package from the mold,
Make a gate break at the second lower gate 20,
The cull 21 and the package are separated, and the resin sealing is completed.

The steps after sealing include tie bar cutting step, plating step, cutting and separating step, sorting step, molding and
Although the hanging pin cutting process is performed in order, the upper and lower resin pool portions 14 and 12 remaining on the lead frame 7a are removed by a tie bar cutting process, a hanging pin cutting process, and the like.

On the other hand, an example in which a shutter is provided at the gate portion and the gate break is omitted is described in Japanese Patent Laid-Open No. 3-284921. Referring to FIG. 5, which is a cross-sectional view of the manufacturing process of the semiconductor device described in the publication rewritten in accordance with the manufacturing process diagram of the present invention for facilitating the description, the same components as those in FIG. It is attached.

4 is different from that shown in FIG. 4 in that the lead frame 7b has no resin inflow hole, and therefore the die is flattened without forming a drawing angle, and the lower die 2c is provided with a shutter 22c. That is what is being done. Other components and process cross-sectional views (a) to (e) are the same as those in FIG.

In this conventional example, the resin in the runner portion 11 from the central portion of the lead frame 7b to the side surface of the package is removed by the shutter 22c.

Further, referring to FIG. 6 which shows an example of a process sectional view in which the shape of the shutter is inclined, in this figure, the same components as those in FIG. 5 are denoted by the same reference numerals.

The difference from FIG. 5 is that a shutter 22d which has a narrower width than the shutter 22c is used according to the shape of the diaphragm angle of the diaphragm portion. Other components and process cross-sectional views (a) to (e) are the same as those in FIG.

In this conventional example, the resin in the gate portion 16a is obliquely removed to the side surface of the package by the shutter 22d.

[0020]

As described above, in the conventional resin encapsulation device for a semiconductor device, in order to ensure that the upper resin puddle and the lower resin puddle remain in the lead frame, the gate break is eliminated. When performing, break from the second lower gate. That is, referring to FIG. 7A showing a cross-sectional view of a package after a conventional gate break and FIG. 7B showing a cross-sectional view of a package showing an example of a defective gate break, from the second lower gate, When a break occurs, the upper and lower resin yield parts are left and the lower 2
The resin from the step gate to the end of the lead frame is dropped off.

Referring to FIG. 7B, which is a sectional view of a package showing an example of a gate break defect, a gate break defect may occur in which the upper and lower resin yield portions are missing depending on the method of the gate break. There is.

That is, in the finishing step, particularly in the tie bar cutting step, the structure of the die is like a comb tooth having a tooth thickness of about 0.2 mm for cutting the tie bar. This comb tooth has a drawback that if the resin having a bad shape left in the steps after the sealing step comes off due to the bad shape as described above and the resin scrap is caught, the comb tooth is broken and the mold is damaged. .

Further, since the encapsulating resin passes through the two gates of the lower second stage gate and the lower first stage gate in the route inside the runner until it reaches the cavity, the amount of heat received by the encapsulating resin increases. Then, the curing of the resin proceeds. Therefore, there is a drawback that the resistance between the contacting wire and the resin flow increases and the resistance of the wire flow or the resin flow with the contacting island increases and the island shift increases.

On the other hand, in the case of the conventional example in which the gate break is omitted by providing a shutter in the gate portion, a shutter having a surface parallel to the lead frame is used so that unnecessary resin is not left on the back surface of the lead frame. There is a need.

That is, referring to FIG. 8 showing the shape of the gate throttle portion in a sectional view, it is necessary to provide the throttle portion in order to introduce the resin into the cavity portion. The runner part is flattened. Therefore, when the resin is filled, the resin flow on the lower surface of the package becomes easy to flow due to a decrease in the flow resistance in the middle, so that the voids frequently occur due to the difference in the resin filling between the upper and lower surfaces of the lead frame or the island shift becomes large. There is.

Although the resin remaining in the gate is not generated, the resin in the runner portion remains, so the step of separating the package from the cull cannot be omitted.

To remove all the runners from the gate to the end of the lead frame where the runners are arranged by using a shutter in order to omit the gate break process, the gate aperture angle must be flattened. The depth of the gate and the runner is the same, and the resin flow under the cavity precedes. In other words, the upper surface of the shutter must be parallel to the lower surface of the lead frame in order to remove all the resin in the runner section. If the runner section has an aperture angle, the shutter upper surface will also have an aperture angle. When is driven upward, the tip of the aperture angle of the shutter naturally reaches the bottom surface of the lead frame first, and it becomes impossible to close the shutter any more.

If the shutter upper surface is entirely flattened ignoring the diaphragm angle, when the shutter is driven downward to open, the hypotenuse side of the diaphragm angle of the lower mold has the horizontal plane of the shutter upper surface and the lower mold. The gap opens by the difference in the angle of the slope,
Since the resin leaks from there, it is not possible to completely remove the resin in the runner portion having the drawing angle.

Further, in the case of the conventional example in which the shutter is slanted, since the upper surface of the shutter is slanted in conformity with the gate shape, it is possible to cut the resin of the gate by closing the shutter, but the runner portion Since the resin cannot be removed, there is a drawback that the gate break step cannot be omitted in order to remove the runner portion and the lead frame frame.

The object of the present invention was made in view of the above-mentioned drawbacks. The resin in the upper and lower resin reservoirs is surely left, and both the package and cull separation step and the gate break step are omitted. It is an object of the present invention to provide a resin-sealing mold for a semiconductor device and a manufacturing method thereof.

[0031]

The features of the resin encapsulation device for a semiconductor device of the present invention are: a cavity portion which is preliminarily matched to a predetermined semiconductor package shape; an air vent portion for depressurizing the pressure in the cavity; and a resin reservoir portion. There is an upper die and a lower die in which a gate throttle portion having a throttle angle for molding and a runner portion serving as a resin flow path into the cavity through the gate throttle portion are formed, respectively. After clamping the lead frame mounting the semiconductor chip between the molds, the resin of the gate throttle part sealed through the runner part provided on the back surface of the hanging pin side corner area of the lead frame is sealed. In a resin sealing device for a semiconductor device, in which a shutter provided in the gate diaphragm portion of the lower mold is vertically driven to remove the shutter, the shutter includes the lower metal mold. Certain of the runner portion of the resin is provided on the runner portion have a first shutter length to be removed from the end of the lead frame to stop angle start point of the gate aperture portion.

Further, the shutter may have a second shutter length for removing the resin of the runner portion from the end portion of the lead frame by a predetermined length.

Further, the gate narrowing portion may be formed only on the lower die, and the lower die may be combined with the upper die having the flattened gate narrowing portion.

The resin sealing method for a semiconductor device according to the present invention is characterized in that a cavity portion previously matched to a predetermined semiconductor package shape, an air vent portion for venting the pressure in the cavity, and a squeezing angle for molding a resin reservoir portion are provided. Using the upper die and the lower die in which a gate narrowing portion having a groove and a runner portion serving as a resin flow path into the cavity through the gate narrowing portion are formed respectively, a semiconductor is provided between these molds. After the die is clamped with the lead frame on which the chip is mounted, the resin of the gate throttle portion sealed through the runner portion arranged on the back surface of the hanging pin side corner area of the lead frame is sealed with the resin of the lower die. In a resin sealing method for a semiconductor device, in which a shutter provided in the gate diaphragm is driven up and down to remove the shutter, the shutter of the lower mold is replaced with the shutter of the lower mold. Provided toner portion from the end portion of the lead frame to stop angle start point of the gate aperture portion first
Using a first shutter having a shutter length of, and driving the first shutter in an upward direction before the resin filled in the cavity is cured, the gate throttle unit is moved from an end of the lead frame. The purpose is to remove the resin up to the starting point of the drawing angle.

In place of the shutter, a second shutter having a second predetermined length from the end portion of the lead frame provided on the runner portion of the lower mold is used. It is possible to remove the resin for the predetermined second shutter length from the end portion.

Further, the gate throttle portion is formed only on the lower die, and in the runner portion formed by the combination of the lower die and the upper die with the gate throttle portion flattened, the first die is formed. Is used to remove the resin in the runner portion with the first shutter length from the end portion of the lead frame to the aperture angle starting point of the gate aperture portion, or the lead frame is used with the second shutter. It is also possible to remove the resin of the runner portion by the second shutter length which is predetermined from the end portion of the.

[0037]

First, a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1A is a cross-sectional view of the die and the lead frame cut diagonally on the hanging pins in the step of resin-sealing the lead frame on which the semiconductor chip is mounted in the first embodiment. 1 is a cross-sectional view of the mold and the lead frame before encapsulation. FIG. 1 (b) is a cross-sectional view of a mold clamped state by an upper mold and a lower mold before the start of encapsulation.
1C is a cross-sectional view of the resin-filled state, FIG. 1D is a cross-sectional view of the state in which the shutter is closed after the resin-filling, and FIG. 1E.
FIG. 6 is a cross-sectional view showing a state in which a shutter closed after encapsulation is opened and a package is separated from a mold by ejector pins.

Referring to FIGS. 1 (a) to 1 (e) together, a cavity 17 matched to the shape of the semiconductor package, an air vent 18 for venting the pressure in the cavity, and a resin reservoir molding part. An upper die 1a and a lower die 2a, which are formed with gate throttle portions 15 and 16a having a throttle angle, a runner portion 11 serving as a resin flow path of the gate portion, and a transfer pot 8 for adjusting a resin flow rate.
The lower mold 2a has a shutter 2 that moves vertically and opens and closes the inside of the runner to remove the resin inside the runner.
2a is provided. The position where the shutter 22a is provided corresponds to the position where the shutter 22a has a length that covers from the end of the lead frame 7a to the start point of the gate aperture angle. That is, the arrangement of the shutter 22a is determined so that the resin reservoir 12 of the lower mold 2a remains without fail, which is a feature of the structure of the lower mold in this embodiment.

A lead frame on which a semiconductor chip is mounted is sandwiched between these molds as in the conventional case, and the mold is clamped to mold a semiconductor package.

The resin molding method for a semiconductor device using the lower mold of the present invention described above, referring again to FIGS. 1 (a) to 1 (e), shows that the upper mold is heated in advance to a desired temperature. The semiconductor chip 5 is fixed to the island 4 by using at least the silver paste 3 on the lower mold 2a of the mold 1a and the lower mold 2a, and the electrodes (not formed) formed on the semiconductor chip 5 through the bonding wires 6. The lead frame 7a is bonded to the inner lead (shown in the figure) (FIG. 1A).

Next, the resin tablet 9 is put into the transfer pot 8, the lower mold 2a is pushed up, and the lead frame 7a is clamped to perform mold clamping (FIG. 1).
(B)).

Next, after the resin tablet 9 is softened by the heat of the lower mold 2a and the plunger 10 for pressing the tablet rises, the resin flows through the runner portion 11 and first flows into the lower resin reservoir portion 12. , Then lead frame 7
They flow into the upper resin reservoirs 14 through the resin inflow holes 13 provided in a.

The resin that has flowed into the resin reservoirs 12 and 14 flows toward the upper gate 15 and the lower gate 16a. The resin that has passed through the upper gate 15 and the lower gate 16a fills the inside of the cavity 17 while degassing the air that had been inside the cavity 17 from the air vent 18 before sealing (FIG. 1 (c)). The sealing is completed when the inside is sufficiently spread.

Thereafter, before the resin is cured, the shutter 2
2a is lifted to remove the resin from the start point of the gate throttle portion to the end of the lead frame, and is held in the mold clamped state until the curing of the resin is completed (FIG. 1).
(D)).

The shutter 22a seen from above at this time
Similarly, the lateral width of the runner must be the same as the groove width of the runner when viewed from the top, but if the groove width of the runner 11 is narrow, the amount of heat received by the resin flowing in the runner will increase, so The width needs to be 2 mm or more. Therefore, it is desirable that the lateral width of the shutter portion is 2 mm or more.

After the resin is cured, the lower mold 2a on the movable side is opened, the ejector pins 19 are projected, and the sealed package is released from the mold (FIG. 1 (e)).

When the sealed package is taken out of the mold, the resin of the cull 21 and the package is removed by the shutter, so that the semiconductor device can be resin-sealed without performing a gate break.

The upper and lower resin reservoirs 14 and 12 remaining on the lead frame 7a are removed in a step after the sealing step such as a tie bar cutting step and a hanging pin cutting step.

FIG. 2 is a sectional view of the die and the lead frame before encapsulation in the step of resin-sealing the lead frame on which the semiconductor chip is mounted in the second embodiment.
(A), FIG. 2 (b) showing a cross-sectional view of a mold clamped by an upper mold and a lower mold before the start of encapsulation, FIG. 2 (c) showing a cross-sectional view of a resin encapsulation start condition, resin FIG. 2D is a cross-sectional view showing a state in which the shutter is closed after encapsulation, and FIG. 2D is a cross-sectional view in which the shutter is closed after encapsulation and the package is separated from the mold by ejector pins.
Referring to (e), the difference from the first embodiment is that the lead frame 7b is not provided with a resin inflow hole, and therefore the upper die 1b is provided with an upper resin reservoir portion and a throttle portion for the gate portion. That is not done.

The other components of the mold are the same as those of the first embodiment, and the same components are designated by the same reference numerals.

That is, referring to FIGS. 2A to 2E, this embodiment relates to a resin sealing mold having a gate portion only in the lower mold 2a, and the shutter 22a described in the first embodiment. It is an example to which the structure of is applied.

In the resin encapsulation method for a semiconductor device using the mold having the above-described structure, at least the silver paste 3 is placed on the lower mold 2a of the upper mold 1b and the lower mold 2a which are heated to a desired temperature in advance. The semiconductor chip 5 is fixed to the island 4 by using it, and the lead frame 7b in which the electrodes provided on the semiconductor chip 5 and the inner leads are bonded and connected is set via the bonding wires 6 (FIG. 2A).

Next, the resin tablet 9 is put into the transfer pot 8, the lower mold 2a is pushed up, and the lead frame 7b is clamped to perform mold clamping (FIG. 2).
(B)).

Next, after the resin tablet 9 is softened by the heat of the lower mold 2a and the plunger 10 for pressing the tablet rises, the resin flows through the runner portion 11 and flows into the lower resin reservoir portion 12.

The resin flowing into the resin reservoir 12 flows toward the lower gate 16a. The resin that has passed through the lower gate 16a fills the inside of the cavity 17 while evacuating the air existing in the cavity 17 from the air vent 18 before sealing (FIG. 2 (c)), and the resin is sufficiently filled in the cavity. The sealing is completed when it is spread.

After that, before the resin is cured, the shutter 2
2a is raised to remove the resin from the starting point of the gate throttle portion to the end of the lead frame 7b, and is held in a mold clamped state until the curing of the resin is completed (FIG. 2 (d)).

The width of the shutter 22a at this time is the first
Similar to the embodiment described above, the groove width of the runner portion needs to be 2 mm or more, and the lateral width of the shutter portion is preferably 2 mm or more.

After the resin is cured, the lower mold 2a on the movable side is opened, the ejector pin 19 is projected, and the sealed package is released from the mold (FIG. 2 (e)).

When the sealed package is taken out from the mold, the resin of the cull 21 and the package is removed by the shutter, so that the semiconductor device can be resin-sealed without performing a gate break.

In this case as well, the lower resin reservoirs 14 and 12 remaining on the lead frame 7b are removed in a step after the sealing step such as a tie bar cutting step and a hanging pin cutting step.

FIG. 3 is a cross-sectional view of the mold and the lead frame before encapsulation, which is a step of resin-sealing the lead frame on which the semiconductor chip is mounted in the third embodiment.
(A), FIG. 3 (b) showing a cross-sectional view of a mold clamped by an upper mold and a lower mold before the start of encapsulation, FIG. 3 (c) showing a cross-sectional view of a resin encapsulation start condition, resin FIG. 3D is a sectional view showing a state where the shutter is closed after encapsulation, and FIG. 3D is a sectional view showing a state where the shutter closed after encapsulation is opened and the package is separated from the mold by ejector pins.
Referring to (e), the difference from the second embodiment is that the length along the groove of the runner portion of the shutter 22b is about 1/5 shorter than that of the second embodiment, That is, the shutter 22a is provided in the lower mold 2a so as to correspond to the position where the resin near the end of the lead frame 7b can be removed.

The other components of the mold are the same as those of the second embodiment, and the same components are designated by the same reference numerals.

Referring to FIGS. 3 (a) to 3 (e), a method of encapsulating a resin in a semiconductor device using the mold having the above-described structure will be described. In this embodiment, the lower mold 2a is sealed with a resin having a gate portion. Regarding the mold for use, the semiconductor chip 5 is fixed to the island 4 by using at least the silver paste 3 on the lower mold 2a of the upper mold 1b and the lower mold 2a which have been heated to a desired temperature, and the bonding wire 6 The lead frame 7b, in which the electrodes provided on the semiconductor chip 5 and the inner leads are bonded and connected, is set via (FIG. 3A).

Next, the transfer pot 9 is charged, the lower mold 2a is pushed up, and the lead frame 7b is clamped, and the mold is clamped (FIG. 3 (b)).

Next, after the resin tablet 9 is softened by the heat of the lower mold 2a and the plunger 10 for pressing the tablet rises, the resin flows through the runner portion 11 and flows into the lower resin reservoir portion 12.

The resin that has flowed into the resin reservoir 12 flows toward the lower gate 16a. The resin that has passed through the lower gate 16a fills the inside of the cavity 17 (FIG. 3 (c)) while evacuating the air inside the cavity 17 from the air vent 18 before the sealing (FIG. 3 (c)). The sealing is completed when it is spread.

Then, before the resin is cured, the shutter 2
2b is raised to remove only the resin of a predetermined short distance along the groove of the runner portion from the end of the lead frame 7b, and is held in the mold clamped state until the curing of the resin is completed (FIG. 3). (D)).

At this time, the shutter length is such that only a portion near the end of the lead frame 7b is removed, and the cross-sectional area of the shutter becomes small, so the shutter 22
It is possible to reduce the driving force required when raising b.

However, if the resin is removed at the end of the lead frame, the resin of the runner portion 11 remaining on the lead frame may be caught by the device when the lead frame is conveyed in the encapsulation process and subsequent steps. ,
At least the resin of 3 mm or more needs to be removed from the end portion of the lead frame along the groove of the runner portion. Therefore, it is preferable that the shutter length of the shutter 22b is 3 mm or more.

Next, the lower mold 2a on the movable side after the resin is cured
Opens, the ejector pin 19 projects, and the sealed package is released from the mold (FIG. 3E).

When the sealed package is taken out of the mold, the resin in the cull 21 and the package is shuttered 22b.
Therefore, the semiconductor device can be resin-sealed without performing a gate break.

In this case as well, the upper and lower resin reservoirs 14 and 12 remaining on the lead frame 7b are removed in a step after the sealing step such as a tie bar cutting step and a hanging pin cutting step.

According to the above-described first to third embodiments, by providing the runner portion with the shutter which is conventionally provided in the gate portion, the shutter can be closed even if the gate shape has the aperture angle. The gate break process can be omitted.

Normally, the shutter is provided in the gate portion so as not to generate the remaining gate, but in the present invention, only the portion that can be surely removed in the sealing step is removed by the shutter, and the gate throttle portion is removed in the finishing step. The breakage at the gate break is eliminated.

In the conventional example, when the resin is filled, the shutter is first closed, the runner portion is filled with the resin, then the shutter is opened to fill the resin in the cavity, and then the shutter is closed again. When the shutter is closed, pressure is applied to the resin inside the runner,
At the moment the shutter is opened, the resin jumps out of the gate vigorously, which accelerates the resin flow rate and causes wire deformation and island shift. However, according to this embodiment, since the shutter is closed only after the cavity is filled with the resin, the above-mentioned resin flow velocity does not increase, and conventionally, the sealing resin is used as the lower second stage gate. And the lower gate was also passed through the gate twice, but by providing a shutter from the start point of the gate aperture angle to the tip of the lead frame, the resin sealing only needs to pass through the gate once. Since it is possible to prevent the hardening of the resin from proceeding, it is possible to reduce wire flow and island shift.

Elimination of the occurrence of breakage in the above-mentioned gate break, and a significant reduction in wire flow and island shift due to the encapsulating resin are shown in Table 1 which compares the occurrence rate of breakage from the lower gate with the conventional example. Referring to Table 2 which compares the shift with the conventional example, the fracture occurrence rate due to the gate break of the gate portion is 1.3% to 0%, the wire flow is 210 μ to 130 μ, and the island shift is 85 μ to 5 μ.
It is reduced to 3μ.

[0078]

[Table 1]

[0079]

[Table 2]

[0080]

As described above, the resin encapsulating method and the resin encapsulating apparatus for a semiconductor device according to the present invention have conventionally been provided with a drawing angle for molding the resin reservoir portion in order to prevent the gate portion from falling off during the gate break. A shutter provided between the starting point of the gate throttle angle and the end of the lead frame with the encapsulating resin being semi-cured. The gate break process can be omitted by removing the runners other than the upper and lower resin reservoirs that should be left securely on the lead frame. It has become possible to prevent the occurrence of breakage at the gate part of the.

Conventionally, the sealing resin has been passed through the gate twice, the lower second-stage gate and the lower first-stage gate, but from the starting point of the gate squeezing angle of the lower mold to the end of the lead frame. By opening and closing the shutter on the runner section up to, the resin encapsulation only needs to pass through the gate once, so it is possible to prevent the curing of the resin from proceeding, wire flow and island shift. It has an effect that can be reduced.

[Brief description of drawings]

FIG. 1A is a sectional view of a die and a lead frame before encapsulation, which is a step of resin-sealing a lead frame on which a semiconductor chip according to the first embodiment is mounted. (B) is a cross-sectional view of a state where the upper die and the lower die are clamped before the encapsulation is started. (C) is a cross-sectional view of a state in which resin encapsulation is started. (D) is a cross-sectional view of the state in which the shutter is closed after the resin is sealed. (E) is a cross-sectional view showing a state in which the shutter closed after encapsulation is opened and the package is separated from the mold by ejector pins.

FIG. 2A is a cross-sectional view of a mold and a lead frame before encapsulation. (B) is a cross-sectional view of a state where the upper die and the lower die are clamped before the encapsulation is started. (C) is a cross-sectional view of a state in which resin encapsulation is started. (D) is a cross-sectional view of the state in which the shutter is closed after the resin is sealed. (E) is a cross-sectional view showing a state in which the shutter closed after encapsulation is opened and the package is separated from the mold by ejector pins.

FIG. 3A is a cross-sectional view of a mold and a lead frame before encapsulation. (B) is a cross-sectional view of a state where the upper die and the lower die are clamped before the encapsulation is started. (C) is a cross-sectional view of a state in which resin encapsulation is started. (D) is a cross-sectional view of the state in which the shutter is closed after the resin is sealed. (E) is a cross-sectional view showing a state in which the shutter closed after encapsulation is opened and the package is separated from the mold by ejector pins.

FIG. 4A is a cross-sectional view of a mold and a lead frame before encapsulation, which is a step of resin-sealing a lead frame on which a semiconductor chip according to a conventional example is mounted. (B)
FIG. 4 is a cross-sectional view of a state where the upper die and the lower die are clamped before the start of sealing. (C) is a cross-sectional view showing a state in which resin encapsulation has started. (D) is a cross-sectional view of the state after resin encapsulation. (E) is a cross-sectional view showing a state in which the package after encapsulation is separated from the mold by ejector pins.

FIG. 5A is a step of resin-sealing a lead frame on which a semiconductor chip according to another conventional example is mounted,
It is a sectional view of a metallic mold and a lead frame before enclosing.
(B) is a cross-sectional view of a state where the upper die and the lower die are clamped before the encapsulation is started. (C) is a cross-sectional view of a state in which resin encapsulation is started. (D) is a cross-sectional view of the state in which the shutter is closed after the resin is sealed. (E) is a cross-sectional view showing a state in which the shutter closed after encapsulation is opened and the package is separated from the mold by ejector pins.

FIG. 6A is a sectional view of a mold and a lead frame before encapsulation, which is a step of resin-sealing a lead frame on which a semiconductor chip according to still another conventional example is mounted. (B) is a cross-sectional view of a state where the upper die and the lower die are clamped before the encapsulation is started. (C) is a cross-sectional view of a state in which resin encapsulation is started. (D) is a cross-sectional view of the state in which the shutter is closed after the resin is sealed. (E) is a cross-sectional view showing a state in which the shutter closed after encapsulation is opened and the package is separated from the mold by ejector pins.

FIG. 7A is a cross-sectional view of a conventional package after a gate break. (B) is a sectional view of a package showing an example of a gate break defect.

FIG. 8A is a cross-sectional view for explaining the shape of a conventional gate throttle portion.

[Explanation of symbols]

 1a, 1b, 1c Upper mold 2a, 2b, 2c Lower mold 3 Silver paste 4 Island 5 Semiconductor chip 6 Bonding wire 7a, 7b Lead frame 8 Transfer pot 9 Resin tablet 10 Plunger 11 Liner 12 Lower resin reservoir 13 Resin Inflow hole 14 Upper resin reservoir 15 Upper gate 16 Lower gate (lower first stage gate) 17 Cavity 18 Air vent 19 Ejector pin 20 Lower second stage gate 21 Culls 22a, 22b, 22c, 22d Shutter

Claims (6)

[Claims] 1. A cavity portion which is preliminarily fitted to a predetermined semiconductor package shape, an air vent portion for venting the pressure in the cavity, a gate throttle portion having a throttle angle for molding a resin reservoir portion, and the gate throttle portion. The upper mold and the lower mold, each of which has a runner part that serves as a resin flow path into the cavity, and a lead frame on which a semiconductor chip is mounted is sandwiched between these molds and the mold is clamped. , The resin of the gate throttle part sealed through the runner part provided on the back surface of the hanging pin side corner area of the lead frame, and the shutter provided in the gate throttle part of the lower mold are moved up and down. In a resin sealing device for a semiconductor device, which is driven in a direction to remove the resin, the shutter is provided in the runner portion of the lower mold, and the resin of the runner portion is removed from the runner portion. A resin sealing device for a semiconductor device, which has a first shutter length for removing from an end portion of a window frame to a start point of a diaphragm angle of the gate diaphragm portion. 2. The resin sealing device for a semiconductor device according to claim 1, wherein the shutter has a second shutter length for removing the resin of the runner portion from the end portion of the lead frame by a predetermined length. 3. The semiconductor device according to claim 1, wherein the gate throttle portion is formed only on the lower die, and the lower die and the gate throttle portion are combined with each other in a flattened upper die. Resin sealing device. 4. A cavity portion which is preliminarily fitted to a predetermined semiconductor package shape, an air vent portion for venting the pressure in the cavity, a gate throttle portion having a throttle angle for molding a resin reservoir portion, and the gate throttle portion. After the mold is clamped, using the upper mold and the lower mold that have the runner part that becomes the resin flow path into the cavity respectively, sandwich the lead frame mounting the semiconductor chip between these molds. , The resin of the gate throttling portion enclosed through the runner portion disposed on the back surface of the hanging pin side corner area of this lead frame, and the shutter disposed on the gate throttling portion of the lower mold are moved up and down. In a resin sealing method for a semiconductor device, which is driven in a direction to be removed, an end portion of the lead frame provided in the runner portion of the lower mold in place of the shutter. To the start point of the aperture angle of the gate throttle portion, and uses the first shutter having a first shutter length, and drives the first shutter upward before the resin filled in the cavity is cured. Then, the resin from the end portion of the lead frame to the drawing angle starting point of the gate drawing portion is removed, and the resin sealing method for a semiconductor device. 5. The lead frame of the lead frame is replaced by a second shutter having a second predetermined length from the end of the lead frame provided in the runner portion of the lower mold in place of the shutter. 5. The resin encapsulation method for a semiconductor device according to claim 4, wherein the resin having a predetermined second shutter length is removed from an end portion. 6. The first die is formed in a runner portion formed by combining the lower die with the gate die formed only in the lower die and the flat die having the flattened gate die. Is used to remove the resin in the runner portion with the first shutter length from the end portion of the lead frame to the aperture angle starting point of the gate aperture portion, or the lead frame is used with the second shutter. 6. The resin encapsulation method for a semiconductor device according to claim 4, wherein the resin of the runner portion is removed by the second shutter length which is predetermined from the end portion of the.