JPS61292329A - Forming device for resin-sealing semiconductor - Google Patents

Abstract

PURPOSE:To improve the operating efficiency by providing lower mold movable, providing a plurality of transfer cylinders and a pot, and always engaging plungers with the pot, thereby eliminating the centering of the pot and the plungers at mold mounting time. CONSTITUTION:A lead frame 29 is supplied to a lower mold of transfer molds heated at the prescribed temperature, and sealing resin tablets 30... are supplied to a pot 24. Then, the piston 13 of a clamping transfer cylinder 12 is lifted to clamp upper and lower molds, the piston 28 of a press transfer manifold 14 is then lifted, and the tablets 30 are charged and pressure molded by plungers 27. At this time, uniform pressures are individually applied to the plungers 27 by uniform pressing mechanism 13. Then, the ejector rod 28 of a returning transfer manifold 16 is moved down, and the piston 13 of the cylinder 12 is further moved down to eject the mold products.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to resin sealing, which is a part of the post-process of assembling elements cut into pellets, corresponding to the pre-process of building circuits and elements on semiconductor wafers. This invention relates to a molding device for semiconductor resin encapsulation used in a encapsulation process.

[Technical background of the invention]

Traditionally, in semiconductor product manufacturing, the automation of front-end processes has been slower than that of back-end processes due to the complexity of the process and the extremely dust-averse work environment, but with the recent trend of increasing production scale, it has become possible to establish highly productive manufacturing lines. is required. As a link to this, larger diameter semiconductor wafers are being developed, and at the same time automation of front-end processes is being promoted, and on the other hand, further automation and high operating rates of back-end processes are desired. From this point of view, various improvements have been made in the die bonding and wire bonding of devices cut into semiconductor pellets, and in the process, even in the subsequent resin encapsulation process, more stringent efficiency improvements have been made. pointing. Incidentally, although a transfer molding machine is used in this resin sealing process, the so-called multi-pot type is currently being used. This molding machine is shown in Figures 6 to 1.
This will be explained using Figure 1.

Plate plates (51) (51) placed opposite each other are fixed by columns (50) placed in the vertical direction, and a mold (not numbered) and a slide table (51) are divided into pieces.
2), the upper mold is fixed and the lower mold is movable. Upper plate (51
) is equipped with a transformer cylinder (53), and the tip of its piston (54) is equipped with a plunger (54) for resin injection and pressurization.
55) will be installed.

In the above-mentioned upper mold, a spacer block (57) and a mold base (58) are arranged on an upper mold base plate (56) fixed to a plate-shaped plate (51) to form a hollow part (59), and an ejector plate is attached to the second part. (6o) and the ejector hold (61) are stacked and installed, and furthermore, a cavity plate (62) is also installed on the mold base (58). On the other hand, multiple ejector pins (63)...
is fixed to the ejector hold (61), and is installed so as to be movable in the axial direction of the support column (50) through the mold base (58) and the cavity plate (62). Additionally, a pot (64) is placed in the center of the upper mold to serve as a supply source for the sealing resin.

On the other hand, the lower mold is placed on the slide table (52), including the base plate, spacer block, mold base, hollow part, ejector plate, ejector hold,
Since the cavity plate and the plurality of ejector pins are formed in exactly the same way as the upper mold, they are given the same numbers and their explanation will be omitted. In addition, the ejector pin (63) provided on the upper and lower molds
... are installed in positions where most of them are directly facing each other. An ejector rod (65) that passes through the slide table (52) and the base plate (56) and supports the ejector plate (60) is formed on the lower plate-like plate (51), and the slide table (52) is attached to this lower plate. (
A transfer cylinder (66) that penetrates through the lower plate-shaped plate (
51).

Although the meaning of the mold was not clear in the above description, the parts between the upper mold base plate (51) and the lower mold base plate (51) in FIG. 6 are collectively referred to as a mold.

By the way, in such a transfer mold, after being heated to a certain temperature, a lead frame (68) is installed on the cavity plate (62) of the lower mold, and then, as shown in FIG. 7, a transfer cylinder ( 66) piston (67
) rises and clamps the upper and lower molds.

In step 2, the resin (69) is fed into the pot (64), and usually a tablet-shaped resin is used.

Furthermore, as shown in FIG. 8, a transfer cylinder (53)
The piston (54) descends to release the plunger (55) at the tip.
), the piston (54) of the transfer cylinder (53) rises, and the piston (67) of the transfer cylinder (66) for mold clamping rises as shown in FIG. ) is lowered and the molded product is ejected. A top view of the molded product obtained by this process is shown in FIG. 10, and a cross-sectional view thereof is shown in FIG. 11.

[Problems with background technology]

In the above-mentioned molding machine, the transfer cylinder and the mold are independent of each other, and when installing the mold, it takes time and skill to center the plunger set at the tip of the transfer cylinder piston, the pot installed in the mold, and the plunger. This causes wear on the pot and plunger due to misalignment. Since the mold and plunger are independent, each must be heated to a constant temperature, which results in large variations and many molding defects.

Second, space is required between the pot and plunger to supply the resin, and the plunger must be constantly removed from the pot, resulting in a long plunger stroke.
Pot and plunger wear increases.

Since there is only one plunger, there is a distance from the cull to the resin sealing part as shown in Figure 1O, which requires a long runner, a large amount of resin, and a long injection time. The distance from to each resin sealing part becomes uneven, leading to many molding defects.

The supply of the lead frame requires many operations because the resin supply is a separate operation, and furthermore, the molding time becomes longer because the next operation cannot be started until the resin is melted after the resin is supplied.

[Purpose of the invention]

The present invention provides a novel molding apparatus for semi-filled resin sealing which eliminates the above-mentioned drawbacks, and is particularly aimed at improving the operating rate.

[Summary of the invention]

In the present invention, only the lower mold is movable, and a plurality of transfer cylinders and pots are provided in this N.

A method was adopted in which the plunger is always engaged with the pot. Therefore, the lower mold placed on the slide table has two hollow parts, one of which is provided with a plate that supports the ejector pin group that can be moved up to the top surface of the mold, and the other part is A uniform pressure mechanism is formed in the hollow portion to drive a plunger that transmits pressure to a plurality of pots formed on the top surface of the mold.

A transfer cylinder formed by passing through a slide table was directly connected to the plate, and a transfer cylinder for moving the lower die was also attached to this slide table.

[Embodiments of the invention]

The present invention will be explained in detail with reference to FIGS. 1 and 5.

A plate-shaped plate (2) placed opposite to each other is fixed to the column (2) installed vertically, and each mold is divided into a lower mold between these plates.The upper mold is fixed and the lower mold is fixed. The method was such that only the mold was movable. Furthermore, the upper mold is not provided with a transfer cylinder as in the past, but is fixed on the ejector pin group.

Therefore, the upper mold base plate ■ is fixed to the plate-shaped plate ■, a spacer block (2) and a mold base 0 are installed on the plate to form a hollow part 0, and the ejector plate ■ and the ejector hold ■ are installed here. are arranged in a stacked manner, and a cavity plate ■ is also installed adjacent to the mold base ■. On the other hand, the ejector pin (10)... is locked in the ejector hold (8), and the mold base ■
, and is formed to be movable in the axial direction of the support column (2) by penetrating the cavity plate (0).

On the other hand, a slide table (11) is formed in the vicinity of the other plate-shaped plate (1) between the supports (7) so as to be movable in the axial direction thereof, and the means for achieving this is a transfer cylinder. This transfer cylinder (12) is formed on the slide table (11) and performs its function by a piston (13) that moves through the plate-like plate (2).

The lower mold is provided with a two-stage hollow part, and the lower hollow part is provided with an equal pressure transmission mechanism (13), and the upper mold is provided with an ejector pin mechanism similar to the upper mold.

That is, the pressure transfer manifold (14) is first fixed to the slide table (11), and the spacer block (15) and pullback transfer manifold (16) are stacked thereon to form the lower hollow part (17). An equal pressure transmission mechanism (13) is provided on the second side. This transfer manifold (14) also has a spacer block (1
8) Arrange the mold base (19) and cavity plate (20) to obtain the upper hollow part (21).

The ejector plate (22) is attached to the saw as well as the upper mold.
and an ejector hold (23), and a plurality of ejector pins (24)... are connected to this ejector hold (23).
3), and is formed to be movable in the direction along the axial direction of the support column ω passing through the mold base (18) and the cavity plate (19). The ejector pins (24) are arranged to directly face the ejector pins (10) formed on the upper mold.

A plurality of pots (25) are formed in the lower mold at a position directly opposite to a part of the ejector pin (10) of the upper mold.
The cavity plate (20), mold base (19), ejector hold (23), and ejector plate (2) can be moved in the axial direction of the column (7).
2) and pullback transfer manifold (14)
A through hole is formed in the hole.

The plunger rod (26) is connected to the equal pressure transmitter W (13) placed in the lower hollow part (17), and the dotted line part shown in the figure shows the piping for the hydraulic cylinder, which is the mechanism, and the piston (2g ) (2g) to press and move the plunger rod (26).

A pullback transfer manifold (16), a pressure transfer manifold (14) and a slide table (
11) is provided with a through hole to enable movement of the ejector rod (28), and the ejector plate (21) and ejector hold (22) are suppressed and moved by a transfer cylinder attached to the plate-shaped plate (2).

The equal pressure transmission mechanism (13) is configured so that the same pressure is transmitted to the pot (24) even if there are variations in the amount of resin supplied into the pot. Use springs.

In a molding apparatus having the above configuration, a lead frame (29
) and put the sealing resin tablet (3) into the pot (24).
Next, as shown in Fig. 2, the piston (13) of the mold clamping transfer cylinder (12)
After rising and clamping the upper and lower molds.

Piston (2) of pressurized transfer manifold (14)
8) rises to inject and pressure mold the resin tablet (30) with the plunger (27). This special plunger (
27) can be individually applied with an equal pressure force by the equal pressure mechanism (13).

Next, as shown in FIG. 3, the ejector rod (28) of the pullback transfer manifold (16) is lowered,
Furthermore, the piston (13) of the transfer cylinder (12)
is also lowered and the molded product is ejected. FIG. 5 is a sectional view of the molded product obtained in FIG. 4.

〔Effect of the invention〕

In the molding machine according to the present invention, centering of the pot and plunger is sometimes unnecessary when installing the mold, and wear of the pot and plunger due to this centering can be prevented. Since this mold and plunger are always fitted, they are heated at the same time, and the temperature variation has been reduced from 170±10°C in the conventional machine to 170±3°C, eliminating molding defects due to temperature.

Next, the plunger stroke in the pot is 15
Since the diameter has been significantly narrowed from 0++m to 30mm, wear on the pot and plunger has been reduced to 115mm compared to the conventional one.

As shown in Figure 4, from the cull (30) to the resin sealing part (33
) is short and uniform at 12 m, the amount of resin is reduced by about 10% compared to the conventional type, and molding defects are prevented.

Incidentally, it should be noted that the conventional distance was as long as 220 to 400 I and was non-uniform.

Furthermore, the resin injection time is shortened to 30 seconds to 10 seconds, and since the lead frame and resin are supplied at the same time, machine operations are reduced, and the resin melts during mold clamping, making the next operation possible6. Molding time The time is improved to 180 seconds to 60 seconds, resulting in an improvement in the operating rate, which in turn greatly contributes to the rationalization of the post-process of semiconductor devices, and has a significant practical effect.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a molding machine according to the present invention, Figs. 2 to 4 are sectional views of each operation of the molding machine shown in Fig. 1, and Fig. 4 is a plan view of a molded product obtained from the molding machine shown in Fig. 1. , Fig. 5 is a sectional view of Fig. 4, Fig. 6 is a sectional view of a conventional molding machine, and Figs. 7 to 9 are sectional views of Fig. 6.
10 is a plan view of a molded product obtained by the molding machine shown in FIG. 6, and FIG. 11 is a sectional view of FIG. 1O. Agent Patent Attorney Mr. Inoue Figure 1 Figure 2 Figure 3 Figure 4: Office = 1 ■ Figure 5

Claims (1)

[Claims] Both pillars arranged in the vertical direction, first and second plate-shaped plates provided opposite to each other via the pillars, a first support body having a hollow part fixed to the first plate, and the first support body having a hollow part fixed to the first plate.
a first flat surface formed on a portion of the support body facing the other plate-like plate; a first plate disposed in the hollow portion of the first support body; and a first flat surface formed between the first flat surface and the hollow portion. A support body is provided so as to be movable in the axial direction of the pillar.
A first ejector pin group supported by a plate, a slide table that is locked to the other plate-like plate and movable in the axial direction of the column, and first and second hollow parts placed on the slide table and stacked. a second support formed on a portion of the second support opposite to the first flat surface;
A flat surface, a second plate disposed in a first hollow portion located on the second flat surface side, and a second support between the second flat surface and the first hollow portion are movable in the direction of the column axis. a second ejector pin group supported by the second plate and directly facing the first ejector pin group; an equal pressure mechanism provided in the second hollow portion; a piston in contact therewith; and the first ejector pin group. a plurality of pots formed on the flat surface directly facing one part of the group; a plunger and a plunger rod that provide the equal pressure mechanism and a second support between the plurality of pots so as to be movable in the direction of the column axis; and the other one. It is characterized by comprising a transfer manifold supported by a plate-like plate and capable of moving a slide table between the second plates and a second support in the axial direction of the support, and another piston attached to the slide table. Molding equipment for semiconductor resin encapsulation.