JPS62274629A - Method and apparatus for manufacturing semiconductor device - Google Patents

Abstract

PURPOSE:To prevent intrusion of outer air in a range and to improve the quality and the reliability of a semiconductor device, by performing the molding press of epoxy rein in a lead frame, on which a semiconductor pellet is mounted, and thereafter slowly cooling the device. CONSTITUTION:A semiconductor device assembly is washed and dried. Thereafter, a lead 1b is held between a top force 5a and a bottom force 5b of a molding press machine, which is heated to about 180 deg.C. Fused epoxy resin 6 is compressed and made to flow into a gap between the top and bottom forces 5a and 5b. The peripheral part of a semiconductor pellet 2 is filled with the resin. Then molding press is performed. At this time, the epoxy resin 6 is heated to about 180 deg.C and hardened. Then, the device is immediately sent to the mold curing furnace. The device is slowly cooled in the mold curing furnace at the temperature gradient of DELTATDELTAt<=20 deg.C/sec. After the device is cooled to room temperature 25 deg.C, the device is taken out. Thus the amount of change in epoxy resin 6 during the process of thermal contraction becomes small, and the yield of exfoliation at the contacting interface of a lead frame 1 and the epoxy resin 6 is minimized.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for manufacturing a semiconductor device, in which resin is molded onto a lead frame on which semiconductor pellets are mounted, and an apparatus for manufacturing the same.

[Conventional technology]

Semiconductor devices are made of semiconductor pellets that operate electrically, and are packaged in a small package to prevent external damage and facilitate handling.The package has leads connected to each electrode of the semiconductor pellet. stands out.

A specific example is a dual-in type resin molded "P conductor device." In manufacturing it, first, a plurality of leads arranged in a radial shape, a flat plate arranged at the tips of these leads, and A lead frame consisting of a flat plate placed at the tip of the lead and a frame that binds these is prepared, and after die-bonding a semiconductor pellet onto the flat plate, each electrode of the semiconductor pellet and the corresponding other leads are bonded. The tips are connected by wire bonding. Then, the semiconductor pellet and its riverside portion are covered by molding resin from the front and back surfaces of the lead frame, and only the frame portion of the lead frame is removed using a press or the like. It is completed by bending the lead part in a certain direction.

Note that the structure of such a semiconductor device is, for example,
It is described in detail in Japanese Patent Publication No. 4-5264 and Japanese Patent Publication No. 56-43854.

[Problem that the invention seeks to solve]

However, in a semiconductor device configured in this way, although the resin and each lead are sufficiently bonded and tightly attached at each lead outlet of the resin, in reality, there is a width in the molded part between the resin and each lead. has a small gap of several micrometers.

For this reason, outside air enters through this minute gap, corroding the leads inside the resin, and further expands the gap due to stress on the leads from the outside, resulting in the intrusion of outside air and accelerated corrosion. There is a problem in that the chips themselves connected by bonding are corroded, impairing the quality and reliability of the semiconductor device for long-term use.

A first object of the present invention is to provide a method for manufacturing a semiconductor device that can prevent outside air from entering the resin and improve the quality and reliability of the semiconductor device.

A second object of the present invention is to provide a semiconductor device manufacturing apparatus that can produce such semiconductor devices with high productivity.

[Means for solving problems]

According to an embodiment of the present invention, a method for manufacturing a semiconductor device in which the lead frame and the resin are reliably bonded to each other by molding and pressing an epoxy resin onto a lead frame loaded with semiconductor pellets and then slowly cooling the resin. is provided.

1fcsAccording to one embodiment f11 of the present invention, a mold press machine that mold presses a lead frame and a resin;
By comprising a mold curing furnace for slow cooling after completion of molding), a highly productive semiconductor device manufacturing apparatus is provided.

[Effect]

In the manufacturing method of the present invention, by slow cooling after mold pressing, the adhesive interface between the lead frame and the resin is brought into close contact (the amount of change in thermal contraction of the resin is small during the cooling process).

The manufacturing apparatus according to the present invention is configured with a mold press machine and a mold-near furnace, thereby increasing the number of semiconductor devices manufactured within a unit time.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view of a main part of a semiconductor device for explaining an embodiment of a method for manufacturing a semiconductor device according to the present invention. In the figure, a semiconductor pellet 2 is fixed and mounted on a pellet mounting portion 1a of a lead frame 1 by an Au-8i eutectic 3, and this semiconductor pellet 2 is nailed to a lead 1b of the lead frame 1 with an Au wire 4. Connected by head bonding method. After the semiconductor device assembly thus configured is cleaned and dried, the leads 1b are sandwiched between an upper mold 5a and a lower mold 5b of a mold press machine (not shown) heated to about 180°C. The molten epoxy resin 6 is poured into the gap between the molds 5a and Sb under pressure to fill the periphery of the semiconductor pellet 2, and a mold press is performed. In this case, the epoxy resin 6 is heated to about 180° C. and cured. Next, the semiconductor device heated to about 180°C is taken out to the outside and immediately transferred to a mold curing furnace (not shown) without cooling. It is slowly cooled with a temperature gradient of ≦20°C/see, cooled to room temperature of 25°C, and then taken out to the outside. Thereafter, the lead frame 1 is washed and dried again, and the frame body of the lead frame 1 is cut, and the tips of the leads 1b are attached to the ends of the leads 1b to complete the process.

According to such a method, after curing the epoxy resin 6 on the lead frame 1 on which the semiconductor pellet 2 is mounted, Δ
By performing slow cooling with a temperature gradient of T/Δt≦20°C/see, the cooling temperature difference per unit time υ becomes smaller, so the amount of change in the process of thermal contraction of the epoxy resin 6 is reduced. . Therefore, the occurrence of peeling at the contact interface between the lead frame 1 and the epoxy resin 6 is minimized. In other words, epoxy resin 6 is applied to lead frame 1
1,・' After being cured, it was taken out to the outside, so there was a sudden temperature difference (△
Tmax → 180°C - 25°C = 155°C/5ee), and this rapid cooling action causes cracks in the epoxy resin 6 at the contact interface with the lead frame 1 due to the difference in thermal expansion coefficient between the lead frame 1 and the epoxy resin 6. However, after curing the epoxy resin 6 on the lead frame 1 as in this embodiment, ΔT/Δt≦20
Since the epoxy resin 6 is slowly cooled with a temperature gradient of .degree. C./sec, the total change in thermal contraction of the epoxy resin 6 during the cooling process is small, and therefore no cracks occur.

FIG. 3 is a perspective view showing an embodiment of the semiconductor device manufacturing apparatus according to the present invention, and the same parts as in the previous figures are given the same reference numerals. In the figure, 10 is a turntable that rotates at a predetermined pitch in the direction of the arrow, 11 is a mold press machine 12 that mold-presses the molten epoxy resin into the semiconductor device assembly described above, and the mold-pressed semiconductor device is connected at ΔT/ This is a semiconductor device manufacturing apparatus consisting of a mold curing furnace 13 that performs slow cooling with a temperature gradient of Δt≦20°C/sec.As shown in FIG. A pair of upper and lower molds 5a and 5b, a heating section (not shown) that heats these molds 5a and 5b to a predetermined temperature, and a frame that holds the lead frame 1 (see FIG. 1) on which semiconductor pellets are mounted. A jig 14 is provided, and the mold curing furnace 1
3 and are integrally fixed on the base 15, and as shown in FIG.

In such a configuration, first, the upper mold 5a of the seven-metal press machine 12 is opened upward, the semiconductor device assembly is mounted on the frame jig 14, and the upper mold 5a and the upper mold 5a are opened from the direction of arrow B. After being inserted between the upper mold 5a and the lower mold 5b, the upper mold 5a is closed downward. Next, this upper mold 5a
A heated and melted epoxy resin 6 is poured under pressure into the gap between the epoxy resin 6 and the lower mold 5b, filling the same side of the semiconductor pellet 2, and heated to about 180° C. to harden.

After curing, the frame jig 14 is transferred into the mold cure 13 by an automatic transport means such as a robot (not shown), and the cured epoxy resin 6 is heated at ΔT/Δt≦20°C/se
Cool slowly with a temperature gradient of c. In this way, the second and third
A mold 5a of a frame jig 14, in which a semiconductor device assembly is mounted on the semiconductor device assembly @11 of the second stand, in a manner corresponding to the rotation pitch of the turntable 10 in the direction of the arrow;
By sequentially performing the insertion between the epoxy resin 5b, the epoxy resin 6 mold press, the transfer into the mold curing furnace 13, and the slow cooling, when the first pewter semiconductor device manufacturing apparatus 11 returns to its initial position, the upper The mold 5a is opened upward, and the semiconductor device cooled to approximately room temperature is taken out from inside the mold curing furnace 13 in the direction of arrow C.

According to this configuration, by performing slow cooling after mold-pressing the semiconductor device assembly with the epoxy resin 6, the unit time until the semiconductor device is completed is reduced to only the time required for slow cooling. Although it is longer, the number of semiconductor devices produced per unit time can be increased by adopting a so-called multi-head type configuration including a plurality of manufacturing apparatuses 11.

FIG. 5 is a block diagram showing another embodiment of the dipping device for semiconductor devices according to the present invention, and the same parts as in the previous figures are given the same reference numerals. In the figure, mold press machine 1
A loading section 16 for supplying semiconductor device assemblies is provided in front of the mold curing furnace 2, and an unloader section 17 for taking slowly cooled semiconductor devices is provided at the rear of the mold curing furnace 13. Part 16. Mold press machine 12, mold cure furnace 13 and unloader section 17
A conveyor 18 moving in the direction of arrow E is connected to constitute a semiconductor device manufacturing apparatus 19.

In such a configuration, the semiconductor device assembly is supplied onto the conveyor 18 in the loading section 16, and the upper mold I1.5a and the lower mold 5b in the mold press machine 12 are
After the epoxy resin 6 is mold-pressed in the same manner as described above, it is transported into the mold curing furnace 13, slowly cooled, and discharged into the unrotor section 18.

The semiconductor device manufacturing apparatus 19 configured in this manner has a third
A plurality of units may be used by disposing them on the turntable 10 as shown in the figure, or the same effect as described above can be obtained even if they are used alone.

〔Effect of the invention〕

As explained above, according to the method for manufacturing a semiconductor device according to the present invention, resin is mold-pressed onto a lead frame containing semiconductor pellets, and then slowly cooled, so that the lead frame and the resin are completely adhered to each other, and infiltration of
Since corrosion can be reliably prevented, a semiconductor device with high quality and reliability can be obtained.

1) According to the semiconductor device according to the present invention, the lead frame is made up of a mold press machine that mold-presses the resin and the lead frame, and a mold cure furnace that slowly cools the mold after completion of molding. This has an extremely excellent effect in that a semiconductor device in which the and resin are completely adhered to each other can be obtained with high productivity.

[Brief explanation of the drawing]

抛1 is a sectional view of a main part showing a mold press state for explaining one embodiment of the method for manufacturing a semiconductor device according to the present invention, and FIG. 2 is a characteristic diagram showing a temperature gradient of a mold curing furnace.
FIG. 3 is a perspective view of essential parts showing one embodiment of a semiconductor device manufacturing apparatus according to the present invention, FIG. 4 is a detailed side view of the manufacturing apparatus shown in FIG. 3, and FIG. 5 is another embodiment of the present invention. 1 is a side view of an example semiconductor device manufacturing apparatus; FIG. 1Φ...Lead frame, 1a...Pellet mounting part, 1b...Lead, 2...Semiconductor pellet, 3...Au-8i eutectic, 4...Au wire,
5a... Upper mold, 5b... Lower mold, 6
...Epoxy resin, 10@...Turntable,
11@--Manufacturing ID, 12--Mold press i
, 13... φ mold cure furnace, 14... Self-frame treatment Fig. 1 Fig. 2
5ec) Figure 3 Figure 4 Figure 15:1 Figure 5

Claims (1)

[Claims] 1. A method for manufacturing a semiconductor device, which comprises mold-pressing a resin onto a lead frame on which semiconductor pellets are mounted, and then slowly cooling the resin. 2. A semiconductor device manufacturing apparatus comprising a mold press machine for mold pressing a lead frame loaded with semiconductor pellets and resin, and a mold curing furnace for slowly cooling the mold press after completion of the mold press.