JPH09129659A - Sheetlike resin for sealing semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the defective molding due to internal void to be avoided by protruding the central part of sheetlike resin for making it thicker than periphery thereby venting air also in the compression molding step of resin pellet. SOLUTION: The sheetlike resin contral part 1 corresponding to the central part of a semiconductor element 6 is made thicker than the sheetlike resin periphery 2 by protruding the central part 1 of at least one side of the sheetlike resin 3 for sealing semiconductor. For example, a semiconductor sealing sheetlike resin 3 mainly comprising epoxy resin in the size of 20mm×20mm×1.0 mm (central part 1.5mm) having a protrusion in diameter of 15mm, central level of 0.5mm is manufactured on one surface of central part using the metallic mold for a tablet machine. Finally, a lead frame 5 with a semiconductor element 6 is held by two each of semiconductor sealing sheetlike resins 3 making the protrusion turn to the opposite side of the semiconductor element 6 so that a resin sealed semiconductor device 8 in size of 20mm×20mm×2.2mm may be manufactured by integrally heat pressurizing for compression molding step.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet-shaped resin for semiconductor encapsulation with less molding defects.

[0002]

2. Description of the Related Art With the recent increase in the types of semiconductor devices,
There are various manufacturing methods. In particular, in addition to the transfer molding method, the number of types of manufacturing methods such as the potting method as well as the resin sealing method using a thermosetting resin such as an epoxy resin are increasing. Recently, one of them is a molding method using a resin sheet or thin resin pellets as disclosed in JP-A-2-257662, and as shown in FIGS. 5 (a) and 5 (b), the lead frame 12 is used. Sheet or resin pellet 10 for encapsulating the semiconductor element 13 face-down connected to the
(Hereinafter referred to as resin pellet) is used for compression molding encapsulation and is used as a substitute for the potting encapsulation resin. Resin pellets 10 used in these manufacturing methods
As shown in FIGS. 4A to 4D, is a shape generally corresponding to the shape of the intended package such as a quadrangle, and a central portion facing the semiconductor chip 13 in FIG. The peripheral portion has the same thickness, and as shown in the front view of FIG. 4B and the side view of FIG. 4C, the resin pellet has a uniform thickness.

[0003]

However, when compression molding is performed using these resin pellets 10 as shown in FIG. 5A, the mold 11, the lead frame 12, the semiconductor element 13 and the resin are It is very difficult to remove the air taken in between and the air contained in the resin pellet 10. As shown in FIG. 5B, the resin-encapsulated semiconductor device 14 manufactured from such a resin pellet 10 has a defect that defective molding is likely to occur due to an increase in internal voids.

The present invention has been made to solve the above-mentioned drawbacks, and provides a sheet-like resin for semiconductor encapsulation in which air is removed even in compression molding of resin pellets to prevent molding defects due to internal voids. It is what

[0005]

Means for Solving the Problems As a result of intensive studies to achieve the above-mentioned object, the present inventor has found that the above-mentioned object can be achieved by making the central portion of the sheet-like resin project and thicken it. They have found and completed the present invention.

That is, according to the present invention, in a sheet-shaped resin for semiconductor encapsulation, by projecting the central portion of at least one surface of the sheet-shaped resin, the central portion of the sheet-shaped resin corresponding to the center of the semiconductor element is the periphery of the semiconductor element. The sheet-shaped resin for semiconductor encapsulation is characterized by being thicker than the peripheral portion of the sheet-shaped resin corresponding to.

Hereinafter, the present invention will be described in detail.

As the resin used in the present invention, a resin generally used in a resin-encapsulated semiconductor device is used and is not particularly limited. As a specific resin, a thermosetting resin such as an epoxy resin or a polyimide resin, a thermoplastic resin such as polyphenylene sulfide, a modified resin thereof, a resin composition or the like is used.

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a view showing a sheet-shaped resin for semiconductor encapsulation of a first embodiment, wherein FIG. 1 (a) is a plan view, FIG. 1 (b) is a front view, and FIG. 1 (c) is a right side view. (D) is a perspective view. As shown in FIGS. 1B and 1C, a peripheral portion 2 to a central portion 1 of a semiconductor-sealing sheet-shaped resin (hereinafter also simply referred to as a sheet) 3 is gently thickened. FIG.
(A)-(d) is a figure which shows the sheet-shaped resin for semiconductor sealing which is a 2nd Example of this invention. In the case of FIG. 2 as well, the central portion 1 of the sheet 3 is thicker than the peripheral portion 2, but in this case, the peripheral portion 2 of the outer periphery of the sheet 3 has a portion 4 having a substantially uniform thickness. The periphery of the element chip in the peripheral portion 2 is suddenly thickened from the uniform thickness portion 4. The central portion 1 corresponding to the center of the element chip is thicker than the thicker peripheral portion 2. This state is shown in FIG.
2B is a front view and FIG. 2C is a right side view.

1 and 2, the central portion 1 is thicker than the peripheral portion 2 only on one side of the sheet 3, but in the present invention, the central portion 1 is thicker than the peripheral portion 2 on both sides. Those that are included in the scope of the present invention. That is, it is sufficient that the central portion 1 is thicker than the peripheral portion 2 on at least one side.

The method for producing these sheets is not particularly limited. For example, a depression is provided in the center of the tableting surface of the punch of a tableting die composed of a die and a punch, and resin powder is It can be manufactured by compression molding using a mold. Or, the softened resin plate on a flat table,
Press the plate with the depression and then cut to cut the central part 1
It is possible to manufacture a sheet in which is thicker than the peripheral portion 2.

Using the sheet manufactured in this way, FIG.
As shown in (a), compression molding for semiconductor element encapsulation can be performed. The semiconductor element 6 adhered to the lead frame 5 is sandwiched from both sides by a sheet 3 having a central portion 1 thicker than a peripheral portion 2, and the whole thereof is compression-molded by using a die 7 and The resin-encapsulated semiconductor device 8 as shown in (b) can be manufactured.

[0014]

By using the sheet-shaped resin for semiconductor encapsulation of the present invention, it is possible to manufacture a highly reliable resin-encapsulated semiconductor device without the generation of internal voids. That is, by using the semiconductor-sealing sheet-shaped resin whose central portion is thicker than the peripheral portion, when the mold is fastened, the semiconductor-sealing sheet-shaped resin melts from the central portion, which is the thickest portion. Then, the resin flows from the central part to the peripheral part, and the air caught in the resin is extruded to the peripheral part and compression-molded. As a result, a resin-sealed semiconductor device without internal voids can be manufactured.

[0015]

Next, the present invention will be described by way of examples.

Example Using a tableting die, 20 mm × 1.0 mm having a convex part with a diameter of 15 mm and a central height of 0.5 mm in the central part of one side (the central part is
A sheet-shaped resin for semiconductor encapsulation containing 1.5 mm of epoxy resin as a main component was manufactured.

Comparative Example A tableting die was used to flatten both sides without any protrusions.
A 20 mm × 20 mm × 1.0 mm epoxy resin-based sheet material for semiconductor encapsulation was manufactured.

Using the sheet resin for semiconductor encapsulation manufactured in the examples and comparative examples, the lead frame with a semiconductor element is made of two sheet resin for semiconductor encapsulation so that the convex portion faces the opposite side of the semiconductor element. A resin-encapsulated semiconductor device having a size of 20 mm × 20 mm × 2.2 mm was manufactured by sandwiching and compression-molding integrally with heating and pressing. The voids on the surface of these resin-sealed semiconductor devices and the internal voids were investigated by polishing the surface to a depth of 0.5 mm. The results are shown in Table 1, and the characteristics of the present invention were excellent, and the effects of the present invention could be confirmed.

[0019]

[Table 1] * 1: The number of voids per resin-sealed semiconductor device with a size of 0.5 mm or more generated on the surface was investigated. * 2: The number of voids per resin-sealed semiconductor device with a size of 0.5 mm or more generated inside was investigated.

[0020]

As is clear from the above description and Table 1, the sheet-shaped resin for semiconductor encapsulation of the present invention is one in which air is removed during compression molding and molding defects due to internal voids are prevented. By using this sheet-shaped resin, a highly reliable resin-sealed semiconductor device can be manufactured.

[Brief description of the drawings]

1A and 1B are views showing an embodiment of a sheet-shaped resin for semiconductor encapsulation of the present invention, in which FIG. 1A is a plan view, FIG. 1B is a front view,
The same (c) is a right side view and the same (d) is a perspective view.

2A and 2B are views showing another embodiment of the sheet-shaped resin for semiconductor encapsulation of the present invention, in which FIG. 2A is a plan view and FIG. 2B is a front view.
The same (c) is a right side view and the same (d) is a perspective view.

3 (a) is a cross-sectional view of compression molding using the sheet-shaped resin for semiconductor encapsulation of FIG. 2, and FIG. 3 (b) is a front view of the obtained resin-encapsulated semiconductor device. is there.

4A and 4B are views showing a conventional resin pellet, in which FIG. 4A is a plan view, FIG. 4B is a front view, FIG. 4C is a right side view, and FIG. 4D is a perspective view.

5 (a) is a sectional view of compression molding using the resin pellet of FIG. 4, and FIG. 5 (b) is a front view of the obtained resin-encapsulated semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Central part 2 Peripheral part 3 Sheet resin for semiconductor encapsulation 4 Uniform thickness part of peripheral part 5,12 Lead frame 6,13 Semiconductor element 7,11 Mold 8,14 Resin encapsulation type semiconductor device 10 Resin pellet

Claims (1)

[Claims] 1. A sheet-shaped resin for encapsulating a semiconductor,
By enlarging at least a central portion of one surface of the sheet-shaped resin, a central portion of the sheet-shaped resin corresponding to the center of the semiconductor element is thicker than a peripheral portion of the sheet-shaped resin corresponding to the periphery of the semiconductor element. Sheet resin.