JPH0445563A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To make it hard to conduct heat by positioning a heat-conductive plate, and next positioning a lead frame apart above this heat-conductive plate, and then fastening upper and lower molds, and injecting sealing resin into the cavities. CONSTITUTION:The plate part 16a of a heat-conductive body 16 is set in the cavity 12a of a lower mold 12, and the positioning hole 16c of the positioning part 16b is set on the positioning pin 14 of the lower mold 12. Hereby, the plate part 16a is positioned in the cavity of the lower mold 12. Next, the lead frame, on which semiconductor element 1 is loaded, is placed on this heat conductor 16, and is positioned in the specified position. And the upper mold 13 is set on the lower mold 12, and those are fastened to unit the heat conductor 16 with the frame 2. After completion of fastening, the sealing member 4 in heated and fused conditions is injected into the cavities 12a and 13a, and those are sealed. Hereby, heat radiation properties can be elevated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a semiconductor device, which involves molding a sealing resin onto a lead frame on which a semiconductor element is mounted.

[Conventional technology]

Conventionally, some semiconductor devices are molded with a sealing resin. This type of semiconductor device will be explained with reference to FIG.

FIG. 5 is a sectional view showing a conventional semiconductor device.

In the figure, 1 is a semiconductor element, and 2 is this semiconductor element 1.
This is a lead frame for mounting.

This lead frame 2 includes an island 2a to which the semiconductor element 1 is bonded, and a surface electrode (not shown) of the semiconductor element 1.
It is composed of an inner lead 2b connected to the inner lead 2b via a thin metal wire 3, and an outer lead 20 formed integrally with the inner lead 2b. 4 is the semiconductor element 1. Fine metal wire 3. This is a sealing member that protects the island 2a, the inner leads 2b, etc. from the external environment and constitutes a pan cage. The sealing member 4 is made of synthetic resin such as epoxy resin, and is molded into a predetermined shape using a mold (not shown).

Next, a method for manufacturing the conventional semiconductor device configured as described above will be described. To assemble this semiconductor device, first, the semiconductor element 1 is joined to the island 2a of the lead frame 2, and the surface electrode of the semiconductor element 1 and the inner lead 2b of the lead frame 2 are connected by the thin metal wire 3.

After the semiconductor element 1 is mounted on the lead frame 2 in this manner, the lead frame 2 is clamped into a mold to mold a sealing member.

This molding die usually consists of a lower die and an upper die. Then, molding is carried out by sandwiching the lead frame 2 between upper and lower molds, and injecting the heated and melted sealing member 4 into the upper and lower molds. After the sealing member 4 is cured, the sealing member 4 is released from the mold together with the lead frame 2, and the resin sealing process is completed. After resin sealing, the semiconductor device is separated from the lead frame 2 by cutting the tips of the outer leads 2C, and the outer leads 2c are bent into a predetermined shape to complete the semiconductor device.

[Problem to be solved by the invention] However, in the conventional semiconductor device configured in this way, the heat of the semiconductor element l is not sufficiently dissipated, and the structure is not suitable for a semiconductor element that generates a lot of heat. . This is because the sealing member 4 made of a resin material conducts heat more easily than metal or the like.

[Spy a-+ means to solve]

In the method for manufacturing a semiconductor device according to the present invention, a heat transfer plate made of a material with high thermal conductivity is positioned in a cavity of a lower mold, and then a lead frame is placed above the heat transfer plate at a distance. After that, the lower mold is clamped and a sealing resin is injected into the cavity.

[For production]

Since the heat transfer plate is buried within the sealing resin and near the semiconductor element, the heat of the semiconductor element is easily transmitted through the sealing resin.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2.

FIG. 1 is an exploded perspective view of a mold used in carrying out the method of manufacturing a semiconductor device of the present invention, and FIG. 2 is a sectional view of a semiconductor device manufactured by the method of manufacturing a semiconductor device of the present invention. In these figures, the same or equivalent members as those explained in FIG. 5 are given the same reference numerals and detailed explanations will be omitted.

In these figures, 11 is a mold for molding the sealing member 4, and this mold 11 includes a lower molding mold 12 and a molding mold clamped onto the lower mold 12. The upper and lower molds 12 and 13 are connected to a drive device (not shown) and are configured to move toward and away from each other.

Cavies 12a and 13a for molding the sealing member 4 are respectively formed in the lower mold 12 and the upper mold 13 so as to fit together. Note that this cavity 12a,
13a is connected to a resin supply device via a runner, a gate (not shown), etc., and is configured to inject heated and melted resin. The lower mold 12 has three positioning bins 14 erected on the sides of the cavity 12a for positioning a thermal conductor, which will be described later, and the upper mold 13 has holes 15 into which the positioning bins 14 are inserted. It is being

Reference numeral 16 denotes a thermal conductor, and this thermal conductor 16 is formed of a plate material with high thermal conductivity (for example, steel material, etc.), and is connected to the lower mold 1.
A flat plate part 16a having a rectangular shape in plan view which is inserted into the cavity 12a of No. 2, and a positioning part 16b which is clamped to the mold die 11 and positions the flat plate part 16a inside the cavity 12a are integrally formed. ing. Note that the thickness of the thermal conductor 16 is set to be approximately equal to the thickness of the lead frame 2. The positioning portion 16b projects laterally from a corner portion of the flat plate portion 16a,
In this embodiment, three are provided. Each positioning portion 16b is unevenly distributed upward with respect to the flat plate portion 16a by bending the base portion. Furthermore, a positioning hole 16c into which the positioning pin 14 of the lower mold 12 is fitted is bored at the protruding end of the positioning portion 16b.

Next, a method for manufacturing a semiconductor device according to the present invention will be explained. First, as shown in FIG. 1, the flat plate part 16a of the heat conductor 16 is inserted into the cavity 12a of the lower mold 12, and the positioning hole 16c of the positioning part 16b is fitted into the positioning pin 14 of the lower mold 12. let As a result, the flat plate portion 16a is positioned within the cavity 12a of the lower mold 12. Note that the position of the flat plate portion 16a within the cavity 12a is set so as to be spaced apart from the bottom surface of the cavity 12a by a predetermined distance. Next, the lead frame 2 on which the semiconductor element 1 is mounted is placed on top of the thermal conductor 16 and positioned at a predetermined position (at a position W where the semiconductor element 1 is positioned within the cavity 12a). In this state, the thermal conductor 1
Since the flat plate portion 16a of No. 6 is unevenly distributed below the positioning portion 16b, the flat plate portion 16a is spaced apart from the lead frame 2. Then, the upper mold 13 is fitted to the lower mold 12, and the thermal conductor 16 is placed inside the mold 11.
and lead frame 2 are clamped together.

At this time, the semiconductor element 1 is inserted into the cavity 13a of the upper mold 13.
It will come within. After the mold clamping is completed, the heated and melted sealing member 4 is placed in the cavity 12a.

13a, the semiconductor device 1. The island 2a, inner lead 2b, thin metal wire 3, thermal conductor 16, etc. are sealed. After the sealing member 4 is cured, the sealing member 4 is released from the mold together with the lead frame 2, and the resin sealing process is completed. After sealing, the positioning portion 16b of the heat conductor 16 protrudes from the sealing member 4, but this protruding portion is cut at the same time as the process of separating the semiconductor device from the lead frame 2.

After this dividing step, the outer lead 2c is bent into a predetermined shape to complete a second semiconductor device as shown in FIG.

Therefore, in the semiconductor device manufactured in this way, the heat conductor 16 is embedded in the sealing member 4 and near the semiconductor element 1, so that the heat of the semiconductor element 1 flows inside the sealing member 4. It becomes easier to convey.

In this embodiment, the thickness of the thermal conductor 16 is approximately equal to that of the lead frame 2, but as shown in FIGS. 3 and 4, the thickness of the thermal conductor 16 is thicker than the lead frame 2.
You can also use

Figures 3 and 4 are views showing other embodiments, where Figure 3 is an exploded perspective view of a mold when a thermal conductor thicker than the lead frame is used, and Figure 4 is a thermal conductor thicker than the lead frame. 1 is a cross-sectional view of a semiconductor device using a conductor. In these figures, the same or equivalent members as those explained in FIGS. 1 and 2 are given the same reference numerals, and detailed explanations will be omitted. 21 is a heat conductor, and the heat conductor 21 used in this embodiment is set to be thicker than that of the embodiment shown in FIGS. 1 and 12, and is formed thicker than the lead frame 2. ing.

Then, the flat plate portion 21a is formed in the same manner as in the previous embodiment.

A positioning portion 21b and a positioning hole 21c are formed. Reference numeral 22 denotes a groove into which the positioning portion 21b of the heat conductor 21 is inserted. The depth dimension of this groove 22 is determined by the depth of the thermal conductor 2.
This is the difference in plate thickness between lead frame 1 and lead frame 2. That is, by fitting the positioning portion 21a into the groove 22, there will be no gap between the lower mold 12 and the upper mold 13 at the time of mold clamping. A semiconductor device manufactured using this thick thermal conductor 21 is shown in FIG. 4. As shown in this embodiment, if the thermal conductor 21 is formed thicker than the lead frame 2, Heat dissipation can be further improved than that of the semiconductor device shown in FIG. Note that the thickness of the thermal conductor 22 can be easily changed by providing the bottom portion of the groove 22 so that it can be raised and lowered, or by interposing a spacer between the bottom surface of the groove 22 and the positioning portion 21b. become. In other words, if you do this,
There is no need to form a plurality of types of lower molds 12 to match the thickness of the heat conductor to be used.

〔Effect of the invention〕

As explained above, IJ application method C! of a semiconductor device according to the present invention! , position a heat transfer plate made of a material with high thermal conductivity in the cavity of the lower mold for molding, then position a lead frame at a distance above this heat transfer plate, and then Since the mold is clamped and the sealing resin is injected into the cavity, the heat transfer plate is embedded within the sealing resin and near the semiconductor element. Therefore, since the heat of the semiconductor element is less likely to be transmitted through the sealing resin and heat dissipation can be improved, a highly reliable semiconductor device can be obtained even if a highly heat-generating semiconductor element is used.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of a mold used in carrying out the method of manufacturing a semiconductor device of the present invention, and FIG. 2 is a sectional view of a semiconductor device manufactured by the method of manufacturing a semiconductor device of the present invention. Figures 3 and 4 are views showing other embodiments, where Figure 3 is an exploded perspective view of a mold when a thermal conductor thicker than the lead frame is used, and Figure 4 is a thermal conductor thicker than the lead frame. 1 is a cross-sectional view of a semiconductor device using a conductor. FIG. 5 is a sectional view showing a conventional semiconductor device. 1... Semiconductor element, 2... Lead frame, 4
...Sealing member, 11...Mold die, 12.
...Lower mold, 13...Upper mold, 12a, 13a.
...Cavity, 16.21...Heat conductor.

Claims (1)

[Claims] In a semiconductor device manufacturing method in which a sealing resin is molded onto a lead frame on which a semiconductor element is mounted, a heat transfer plate made of a material with high thermal conductivity is positioned in a cavity of a lower molding die, and then this A method for manufacturing a semiconductor device, comprising positioning the lead frame above a heat exchanger plate at intervals, and then clamping the lower mold and injecting a sealing resin into the cavity.