JP3195844B2 - Transfer mold equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer molding apparatus, and more particularly, to a transfer molding apparatus and a transfer mold for sealing electronic components with resin, and a transfer molding method using the transfer molding apparatus.

[0002]

2. Description of the Related Art A transfer molding apparatus has been used for sealing electronic parts and semiconductor devices with resin (for example, see Japanese Patent Application Laid-Open No. 4-199645). In a conventional transfer molding apparatus, a molten resin that has been subjected to plunger pressure is pressure-fed and filled into a cavity in a mold via a resin path. The filled resin is solidified to complete the resin sealing.

[0003]

However, the above-mentioned conventional transfer molding apparatus has the following problems. Bubbles contained in the molten resin introduced into the cavity float on the resin liquid surface. As the filling of the resin progresses, the resin level with a high bubble density rises, and the resin level with a high bubble density comes into contact with the lead frame or wafer (particularly remarkable on the lower cavity side). It will be in a sandwiched state. Even if the filling of the resin is completed in this state, since the plunger pressure is effectively acting at the beginning of the completion, the bubbles are in a compressed state. However, when the curing of the resin proceeds and the gate is closed, the plunger pressure does not act on the resin in the cavity. As the curing of the resin progresses, the resin shrinks. Since the curing of the resin proceeds from the outside and the curing of the inside is delayed, the resin pressure inside the inside decreases. The compressed air bubbles expand as the resin pressure decreases, and a peeled portion and a sparse band are generated between the cured resin and the lead frame or wafer. When mounting an electronic component or a semiconductor device that has been subjected to resin sealing containing expanded bubbles, when the electronic component or the semiconductor device is exposed to high temperatures, the air in the bubbles expands, and a so-called popcorn phenomenon occurs to cause the resin layer to be removed. There are problems such as breakage and cracks.

Further, after the filling of the molten resin into the cavity is completed, as the curing of the resin progresses, the volume of the resin shrinks, so that a tensile stress is generated in the resin layer, and the resin sealing portion is warped. There is a problem that. In particular, in the case of an electronic component or a semiconductor device in which the thickness of the resin sealing portion is small, the warpage is remarkable. Therefore, the present invention uses a transfer molding apparatus and a transfer molding die capable of preventing the destruction of the resin-sealed portion at a high temperature and preventing the occurrence of warpage of the resin-sealed portion, and the transfer mold device. An object is to provide a transfer molding method.

[0005]

To solve the above-mentioned problems, the present invention has the following arrangement. That is, an upper mold and a lower mold in which a cavity is formed and one end of which is provided with a slide hole opened in the cavity, and slidably disposed in the slide hole, respectively . A slide member movable toward and away from the cavity; and a driving means for moving the slide member toward and away from the cavity.
Then, the driving means is driven to move each slide member into the cavity.
To the first position away from the
After filling the melted resin, the slide
Move the member to a second position close to the cavity
The molten resin is cured .

[0006] As another configuration, the cavity is formed, and the mold body portion slide hole that opens into the cavity is drilled, while being slidably arranged to slide bore, cavity And a slide member that can move toward and away from the cavity, always biases the slide member in the cavity direction, and when the molten resin is filled in the cavity, the slide member is separated from the cavity by the filling pressure of the molten resin. to allow movement of the first position, after the completion of filling the cavity of the molten resin, in curing the molten resin, it was and a biasing means for moving the slide member to the second position close to the cavity It is characterized by.

[0007]

[Operation] The operation will be described. In the above transfer molding apparatus, when filling the cavity with the molten resin, the slide member is moved to the first position separated from the cavity via the driving means, and after the completion of the filling of the cavity with the molten resin, the molten resin is discharged. At the time of curing, if the slide member is moved to the second position close to the cavity via the driving means, even if the plunger pressure does not act on the cavity when the molten resin is cured, the slide member is pushed. The pressure can prevent the expansion of the air in the bubble. Further, when the molten resin is cured, the resin that has entered the slide hole due to the movement of the slide member can be supplied to the resin sealing portion.

Further , when filling the molten resin into the cavity, the upper and lower slide members move to the first position away from the cavity, and after the filling of the molten resin into the cavity is completed, when the molten resin is cured. Since the slide member moves to the second position close to the cavity by the urging force of the urging means by an amount corresponding to the volume reduced by the curing, the plunger pressure acts inside the cavity when the molten resin is cured. Even without this, the pressing force of the slide member can prevent the expansion of the air in the bubble. To the second position
The resin that has entered the sliding hole of the moved slide member can be supplied to the resin sealing portion.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. First, a first embodiment will be described with reference to FIGS. In FIG. 1, reference numeral 10 denotes an upper mold base to which an upper chase 12 as a mold is attached. On the parting surface (lower surface) of the upper die chase 12, a cavity 14a is formed in a concave shape. Reference numeral 16 denotes a lower mold base, which is a lower mold chase 18 which is a mold.
Is attached. On the parting surface (upper surface) of the lower die chase 18, a cavity 14b is recessed.
Reference numeral 20 denotes a pot, in which a plunger 22 moves up and down to melt a resin 24 (a thermosetting resin such as an epoxy resin or a biphenyl resin) into the cavity 14.
a, 14b. Molten resin 24
Is a cavity 14a in a state where the mold is closed from the pot 20 via the runner 26 and the gate 28 (the state of FIG. 1),
14b.

Next, the structure of a mold (upper chase 12 and lower chase 18) will be described with reference to FIG. 30a is a slide hole, and the upper chase 12
It is provided in the vertical direction. The lower end of the slide hole 30a opens on the inner upper surface of the cavity 14a. Reference numeral 30b denotes a slide hole which is vertically penetrated into the lower die chase 18. The upper end of the slide hole 30b is the cavity 14
b. Reference numeral 32a denotes a slide member, which is disposed in the slide hole 30a so as to be vertically movable. The outer peripheral surface of the slide member 32a is slidable with the inner peripheral surface of the slide hole 30a, and is movable toward and away from the cavity 14a.

Reference numeral 32b denotes a slide member, which is disposed movably in the vertical direction in the slide hole 30b. The outer peripheral surface of the slide member 32b has a slide hole 30b.
Is slidable with the inner peripheral surface of the cavity 14.
It can be moved toward and away from b. Reference numeral 34a denotes an eject pin, which is inserted into the upper die chase 12. The upper end of the eject pin 34a is fixed to the eject pin plate 36a. Eject pin plate part 3
6a is vertically movable within the upper mold base 10 integrally with the eject pin 34a. The eject pin 34a and the eject pin plate portion 36a are constantly urged upward by a spring 38a. When the eject pin 34a is at the uppermost position (the position shown in FIG. 2) with respect to the upper die chase 12, the eject pin 34a
Is flush with the inner upper surface of the cavity 14a.

An eject pin 34b is inserted through the lower die chase 18. The lower end of the eject pin 34b is fixed to the eject pin plate 36b. The eject pin plate portion 36b is vertically movable within the lower mold base 16 integrally with the eject pin 34b. The eject pin 34b and the eject pin plate portion 36b are constantly urged downward by a spring 38b. When the eject pin 34b is at the lowest position (the position shown in FIG. 2) with respect to the lower die chase 18, the upper end surface of the eject pin 34b is
4b is flush with the inner bottom surface.

Reference numeral 40 denotes a semiconductor device which is an example of a member to be molded. The semiconductor device 40 has a cavity 1 when the upper die chase 12 and the lower die chase 18 are closed (the state shown in FIG. 2).
A portion (inner lead portion, IC chip portion, and the like) to be sealed with resin is arranged in a cavity space formed by 4a and 14b. 42a is a first link piece,
It is erected on the upper end of the slide member 32a. The first link piece 42a is connected to the second link piece 4 as shown in FIG.
4a and the slide member 32a in cooperation with the air cylinder 46a fixed to the transfer molding apparatus main body.
Is configured to drive up and down. That is, when the cylinder rod 48a extends upward, the second link piece 4
The slide member 32a moves down by the 4a and the first link piece 42a. On the other hand, when the cylinder rod 48a is shortened downward, the slide member 32a is moved upward by the second link piece 44a and the first link piece 42a.

When the slide member 32a moves up and down, the upper end flange portion 50a of the slide member 32 comes into contact with the upper surface inside the concave portion 52a of the upper mold base 10 and the step portion 54a of the eject pin plate portion 36a. Be regulated. The flange portion 50a is formed of the upper mold base 10.
Of the slide member 32 in contact with the upper surface of the concave portion 52a
The position a is the first position where the slide member 32a is farthest from the cavity 14a. On the other hand, the flange 5
0a is the step portion 54a of the eject pin plate portion 36a.
The position of the slide member 32a in contact with the second position is the second position where the slide member 32a is closest to the cavity 14a. When the slide member 32a is at the second position, the lower end surface of the slide member 32a is
It is flush with the inner upper surface of a.

Reference numeral 42b denotes a first link piece, which is suspended from the lower end of the slide member 32b. First link piece 42b
1 constitutes driving means for moving the slide member 32b up and down in cooperation with the second link piece 44b and the air cylinder 46b fixed to the transfer molding apparatus main body, as clearly shown in FIG. That is, when the cylinder rod 48b extends downward, the second link piece 44b and the first
The slide member 32b is moved upward by the link piece 42b.
On the other hand, when the cylinder rod 48b is shortened upward, the slide member 32b is moved downward by the second link piece 44b and the first link piece 42b.

When the slide member 32b moves up and down, the lower end flange portion 50b of the slide member 32 comes into contact with the inner upper surface of the concave portion 52b of the lower mold base 16 and the step portion 54b of the eject pin plate portion 36b. Be regulated. The flange portion 50b is attached to the lower mold base 16.
Of the slide member 32 in contact with the inner bottom surface of the concave portion 52b
The position b is the first position where the slide member 32b is farthest from the cavity 14b. On the other hand, the flange 5
0b is the step 54b of the eject pin plate 36b.
The position of the slide member 32b in contact with the second position is the second position where the slide member 32b is closest to the cavity 14b. When the slide member 32b is at the second position, the upper end surface of the slide member 32b is
It is flush with the inner bottom surface of b.

A molding method using the transfer molding apparatus having the above configuration will be described with reference to FIGS. As shown in FIG. 2, the mold is closed while the semiconductor device 40 to be resin-sealed is set in the lower mold chase 18. At this time, the slide members 32a, 32b
Is in the first position (the state of FIG. 2). When the mold is closed, the molten resin 24 is pressure-fed from the pot 20 under the pressure of the plunger 22, and is filled into the cavity formed by the cavities 14a and 14b via the runner 26 and the gate 28. At this time, the slide members 32a, 32
Since b is in the first position, the molten resin 24 slightly enters the slide holes 30a and 30b (the state of FIG. 3).

After the filling of the molten resin 24 is completed, the molten resin 24 is heated by a heater (not shown) to start curing.
When the gate 28 is closed, the pressure of the plunger 22 does not act on the molten resin 24. Then, compressed air is supplied from a compressor (not shown) to the air cylinders 46a and 46b, and the slide members 32a and 32b move to the second position (the state of FIG. 4). The movement of the slide members 32a and 32b is further restricted from the second position in the direction of the cavities 14a and 14b by the resin 24 in the cavity space. By the movement of the slide members 32a and 32b,
The slide member 32 is applied to the inner molten resin which has not been cured yet.
Since the pressures of a and 32b act, the bubbles existing in the molten resin 24 and at the interface between the resin 24 and the lead frame of the semiconductor device 40 continue and are maintained in a compressed state.
No bubble expansion occurs. Therefore, a peeled portion and a sparse band do not occur between the lead frame and the lead frame. Also,
Even if the volume shrinks due to the hardening of the molten resin 24, the molten resin 24 that has entered the slide holes 30a and 30b moves toward the cavities 14a and 14b as the slide members 32a and 32b move to the second position. It is pushed out to. By this extrusion, the amount of resin corresponding to the shrinkage can be supplied.

When the curing of the molten resin 24 is completed, the upper mold base 10 and the upper chase 12 move upward to open the mold. When the mold is opened, further movement of the slide members 32a, 32b from the second position in the direction of the cavities 14a, 14b becomes possible, so that the slide members 32a, 32b project into the cavities 14a, 14b. At this time, the flange portions 50a, 50b of the slide members 32a, 32b are connected to the step portions 54 of the eject pin plate portions 36a, 36b.
The eject pin plate portions 36a, 36b also move integrally with the slide members 32a, 32b because they are engaged with the slide members 32a, 32b. Accordingly, the eject pins 34a and 34b also project into the cavities 14a and 14b, and the resin-sealed semiconductor device 40 can be ejected from the cavities 14b (the state of FIG. 5).

Next, a second embodiment will be described with reference to FIG. The second embodiment relates to a transfer mold. Note that the same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and description thereof will be omitted. Cavities 14a and 14b are formed on the parting surfaces of the upper die chase 12 and the lower die chase 18, which are the die body. The sliding holes 30a and 30b are provided through the upper die chase 12 and the lower die chase 18, and one ends are opened in the cavities 14a and 14b. The slide members 32a and 32b are formed in a cylindrical shape with one end face on the side of the cavities 14a and 14b closed. The other ends of the slide members 32a and 32b are located in the recesses 52a and 52b of the upper mold base 10 and the lower mold base 16, and are slidably disposed in the slide holes 30a and 30b. By this slide, the slide member 32
The a and 32b can move toward and away from the cavities 14a and 14b.

The inside of the recesses 52a and 52b and the slide member 3
Coil springs 70a and 70b, which are examples of the urging means, are elastically mounted between the inside of 2a and 32b. The coil springs 70a and 70b are connected to the slide members 32a and 3a.
2b is constantly urged toward the cavities 14a, 14b, and when the molten resin 24 is charged into the cavities 14a, 14b, the slide members 32a, 32b are moved by the filling pressure (plunger pressure) of the molten resin 24. , 14b to the first position (the position shown in FIG. 6) separated from the first position. On the other hand, after filling the cavities 14a and 14b with the molten resin 24, the molten resin 24
When is hardened, the slide members 32a, 32
b is moved to a second position close to the cavities 14a, 14b. When the slide members 32a, 32b reach the second position, the projecting portions 74a, 74b projecting from the outer peripheral surfaces of the slide members 32a, 32b are moved to the upper chase 12,
The cavities 14a, 14b are engaged with the lower die chase 18
Movement in the direction is regulated.

The ejection pins 34a, 34b and the ejection pin plate portions 36a, 36b are protruded by air cylinders 72a, 72b. Rod 7
When the extension members 6a and 76b extend, the pushing members 78a and 78b are pushed toward the cavities 14a and 14b, and the pushing members 78 are pushed.
a, 78b are eject pin plate portions 36a, 36b
Is pushed in the direction of the cavities 14a and 14b, so that the tips of the eject pins 34a and 34b
14b.

A molding method using the transfer mold having the above configuration will be described. The mold is closed with the semiconductor device 40 to be resin-sealed set in the lower mold chase 18. At this time, the slide member 32a,
32b is located at the second position by the elastic force of the coil springs 70a and 70b. When the mold closing is completed, the mold is filled into the cavity space formed by the cavities 14a and 14b via the molten resin 24 gate 28. At this time, the sliding members 32a and 32b receive the filling pressure of the molten resin 24 and move to the first position separated from the cavities 14a and 14b.
a, 30b (state in FIG. 6)

After the filling of the molten resin 24 is completed, the molten resin 24 is heated by a heater (not shown) to start curing.
When the gate 28 is in the closed state, the charging pressure is reduced to the molten resin 24.
And it does not act on the slide members 32a and 32b.
Therefore, the slide members 32a, 32b that have received the urging force of the coil springs 70a, 70b move to the second position. Due to the movement of the slide members 32a, 32b, the slide members 32a, 32b
Since the pressure of 2b acts, the bubbles existing in the molten resin 24 and on the boundary surface between the resin 24 and the lead frame of the semiconductor device 40 continue and are maintained in a compressed state, and the bubbles do not expand. Therefore, a peeled portion and a sparse band do not occur between the lead frame and the lead frame. Even when the volume of the resin shrinks due to the curing of the molten resin 24, the molten resin 24 that has entered the slide holes 30a and 30b moves along with the movement of the slide members 32a and 32b to the second position. It is extruded in the 14b direction. By this extrusion, the amount of resin corresponding to the shrinkage can be supplied.

When the curing of the molten resin 24 is completed, the upper mold base 10 and the upper chase 12 move upward to open the mold. When the mold is opened, the air cylinders 72a, 72b are driven to eject the eject pins 34a, 34b to the cavities 14.
a, Semiconductor Device 40 Protruding into 14b and Sealed with Resin
Can be ejected from the cavity 14b.

Next, a third embodiment will be described with reference to FIG. The third embodiment relates to a transfer molding apparatus. Note that the same components as those of the preceding embodiment are denoted by the same reference numerals as those of the preceding embodiment, and description thereof is omitted. The transfer molding apparatus according to the third embodiment is used for resin sealing of a semiconductor device in which a chip 82 is disposed on a base (lead frame, substrate, film) 80 and a package portion is formed only on the base 80. Can be

In the transfer molding apparatus of the third embodiment, the structures in the lower mold base 16 and the lower chase 18 are simplified. Further, the air in the cavity 14a can be discharged from the gap between the slide member 32a and the slide hole 30a and the gap between the eject pins 34a. Further, even if the volume of the molten resin 24 is reduced due to the curing of the molten resin 24, the molten resin 24 that has entered the slide hole 30a is pushed out toward the cavity 14a as the slide member 32a moves to the second position. By this extrusion, the amount of resin corresponding to the shrinkage can be replenished, and the warpage of the package portion, which usually warps greatly, can be extremely suppressed.

Next, a fourth embodiment will be described with reference to FIG. The fourth embodiment is also an embodiment relating to a transfer molding apparatus. Note that the same components as those of the preceding embodiment are denoted by the same reference numerals as those of the preceding embodiment, and description thereof is omitted. The transfer molding apparatus according to the fourth embodiment includes a base 8
The chip 82 is provided below the base 80 and is used for resin sealing of a semiconductor device in which a package portion is formed only below the base 80.

In the transfer molding apparatus of the fourth embodiment, the structures in the upper mold base 10 and the upper chase 12 are simplified. Also, the slide member 32b
The pressure of the slide member 32b acts on the internal molten resin that has not yet been cured due to the movement of the molten resin.
The air bubbles existing inside and at the boundary surface between the substrate 80 and the resin 24 continue and are maintained in a compressed state, and no expansion of the air bubbles occurs. There is no occurrence of a stripped portion of the resin 24 or a sparse band. Further, the air in the cavity 14b can be discharged from the gap between the slide member 32b and the slide hole 30b and the gap between the eject pins 34b. Further, even if the volume of the resin shrinks due to the hardening of the molten resin 24, the molten resin 24 that has entered the slide hole 30 b is removed by the slide member 3.
With the movement of 2b to the second position, it is pushed out toward the cavity 14b. By this extrusion, the amount of resin corresponding to the shrinkage can be replenished, and the warpage of the package portion, which usually warps greatly, can be extremely suppressed.

In each of the above embodiments, the slide member 3
The front end surfaces of 2a and 32b do not correspond to the entire inner upper and lower surfaces of the cavities 14a and 14b. This is because, when the thickness of the package portion to be sealed with the resin is reduced, the resin 24 does not easily enter the upper and lower portions of the base 80, and the air is easily entangled. Not in. Also, the slide member 32
eject pin 3 to ensure the releasability of a, 32b
In order to make the 4a and 34b protrude into the cavities 14a and 14b, the tip surfaces of the slide members 32a and 32b do not correspond to the entire inner and lower surfaces of the cavities 14a and 14b. Even if the eject pins 34a and 34b are ejected at the ends of the package portion of the semiconductor device 40 or the like, the center portion is also pushed by the slide members 32a and 32b, so that the warpage of the package portion can be suppressed. As described above, various preferred embodiments of the present invention have been described.
The present invention is not limited to the above-described embodiment, but may be modified in many ways without departing from the spirit of the invention.

[0031]

The transfer molding apparatus according to the present invention.
Being use of, in filling the molten resin into the cavity,
The slide members provided in the slide holes of the upper mold and the lower mold are moved to the first position away from the cavity, and after the filling of the molten resin into the cavity, when the molten resin is cured, Since the slide member is moved to the second position close to the cavity via the driving means, even when the plunger pressure does not act in the cavity when the molten resin is hardened, the pressing force of the slide member is reduced within the molten resin. Passing
The expansion of bubbles existing at the interface between the lead frame and the molten resin can be prevented. Further, even if the volume of the molten resin shrinks due to curing, the molten resin moves to the second position.
The resin that has entered the sliding hole of the sliding member can be supplied to the resin sealing portion.

According to another configuration, when filling the molten resin into the cavity, the slide member moves to the first position separated from the cavity, and after the filling of the molten resin into the cavity, the molten resin is filled. When hardening, the slide member moves to the second position close to the cavity by the urging force of the urging means by an amount corresponding to the volume reduced by the hardening. Even if it does not act inside, the pressing force of the slide
In the molten resin, at the interface between the lead frame and the molten resin, etc.
It is possible to prevent the expansion of the air bubbles present in the. Also,
When curing the molten resin, the slide moved to the second position
It is possible to replenish the resin that has entered the slide hole of the sliding member to the resin sealing portion.

Therefore, it is possible to prevent the occurrence of a peeled portion or a density band between the cured resin and the lead frame to be sealed with the resin. In addition, since the inside of the resin-sealed portion does not contain expanded bubbles, the electronic components and the semiconductor device are exposed to high temperature, and the air in the bubbles expands, which may damage the resin-sealed portion or cause cracks. There is no. Furthermore, after the filling of the molten resin into the cavity is completed, even if the volume of the resin shrinks, the resin in the slide hole is replenished into the cavity.
This has a remarkable effect such as the possibility of preventing the resin sealing portion from being warped.

[Brief description of the drawings]

FIG. 1 is a partially broken front view showing a main part of a transfer molding apparatus according to a first embodiment of the present invention.

FIG. 2 is a partial sectional view showing the vicinity of a chase of the transfer molding apparatus of FIG.

FIG. 3 is a partial cross-sectional view showing the vicinity of a chase in a resin-filled state.

FIG. 4 is a partial cross-sectional view showing the vicinity of a chase in a resin cured state.

FIG. 5 is a partial cross-sectional view showing the vicinity of a chase in a release state of the semiconductor device.

FIG. 6 is a partially cutaway front view showing a main part of a transfer molding apparatus including a transfer mold according to a second embodiment of the present invention.

FIG. 7 is a partial sectional view showing the vicinity of a chase in a resin-filled state of a transfer molding apparatus according to a third embodiment of the present invention.

FIG. 8 is a partial sectional view showing the vicinity of a chase in a resin-filled state of a transfer molding apparatus according to a fourth embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 upper mold base 12 upper mold chase 14a, 14b cavity 16 lower mold base 18 lower mold chase 24 resin 30a, 30b slide hole 32a, 32b slide member 40 semiconductor device 42a, 42b first link piece 44a, 44b second Link piece 46a, 46b Air cylinder 70a, 70b Coil spring 80 Base

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 45/00-45/84 H01L 21/56

Claims (3)

(57) [Claims] 1. A cavity is formed, and a slide hole having one end opened in the cavity is formed.
An upper mold and a lower mold , a slide member which is respectively slidably provided in the slide hole, and which is movable toward and away from the cavity; and a slide member which moves the slide member toward and away from the cavity. comprising a drive means, by driving the driving means, calibration of the respective slide member
Move the molten resin to the first position away from the
Fill the cavity, and after filling the molten resin,
Moving the guide member to a second position close to the cavity,
A transfer molding apparatus, wherein the molten resin is cured by heating . 2. A cavity is formed in the cavity.
A mold body portion having a slide hole opened therein , and slidably disposed in the slide hole,
A slide member capable of moving toward and away from the cavity;
When fat is filled in the cavity, the filling pressure of the molten resin
The first member that has separated the slide member from the cavity by force
To the position and finish filling the molten resin cavity.
After that, when the molten resin is cured,
Biasing means for moving to a second position close to the cavity;
Transfer mold equipment characterized by having
Place. 3. The mold body is provided with upper and lower dies.
The slide member and the attachment
The biasing means is provided in each of the slide holes.
3. The transfer molding apparatus according to claim 2, wherein
Place.