JPH08335596A - Manufacture of semiconductor package - Google Patents

Abstract

PURPOSE: To provide the manufacturing method of a semiconductor package by which the high productivity can be realized while mingling of foreign substances and generation of voids in a resin-sealed part are suppressed. CONSTITUTION: A base substrate 1 is divided into a plurality of regions. Outer connection terminals 4 are provided on the surface of the base substrate 1 opposite to the surface on which chips are mounted so as to correspond to the respective divided regions. Semiconductor chips 2 are mounted on the respective divided regions of the base substrate 1. A simple mold 5 for resin sealing is attached to the surface of the base substrate 1 on which the chips are mounted. Then liquid resin 12 which is filtered by a foreign substance eliminating filter beforehand is cast into the simple mold 5 in a vacuum atmosphere in a vacuum chamber 7 and the cast resin 12 is cured to seal the individual semiconductor chips 2 with the resin altogether. Finally, after the simple mold 5 is removed from the base substrate 1, the resin-sealed base substrate 1 is cut along the predetermined section lines to obtain single-chip semiconductor packages.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a resin-sealed semiconductor package.

[0002]

2. Description of the Related Art Conventionally, in a semiconductor package related to an optical device such as a photodiode or a phototransistor, or a CCD or an LED, a packaging form using a transparent resin has been adopted. Among them, as a resin encapsulation method for encapsulating a semiconductor chip mounted on a substrate, a potting method using a low-viscosity liquid resin and a transfer molding method using a die are widely known. ing.

[0003]

However, in the past, no matter which resin encapsulation method is adopted, foreign matter in the resin encapsulation portion for encapsulating a semiconductor chip is used in the manufacture of a semiconductor package related to an optical device. The inclusion of voids and the formation of voids have been one of the causes of lowering the yield of semiconductor packages. Particularly, in the case of transfer molding, since the mold is coated with a mold release agent and resin-sealed, the mold release agent may get into the surface layer of the package and adversely affect the device characteristics. Therefore, it is necessary to polish the surface of the package after molding to remove the release agent, and there is a drawback in terms of productivity as in the potting method in which resin is sealed one by one.

The present invention has been made to solve the above problems, and an object thereof is to manufacture a semiconductor package which suppresses the mixing of foreign matters and the formation of voids in the resin sealing portion and is excellent in productivity. To provide a method.

[0005]

The present invention has been made in order to achieve the above object, and is divided into a plurality of regions and is provided on the surface opposite to the chip mounting surface corresponding to each divided region. A method of manufacturing a semiconductor package using a base substrate having connection terminals, comprising: a first step of mounting a semiconductor chip in each of the divided regions of the base substrate; and resin sealing on the chip mounting surface side of the base substrate. In the second step of attaching the simple mold, the liquid resin previously filtered by the foreign matter removing filter is injected into the simple mold in a vacuum atmosphere, and the injected resin is hardened and mounted on the base substrate. It has a third step of collectively sealing the semiconductor chips with resin, and a fourth step of removing the simple mold from the base substrate and then cutting the resin-sealed base substrate along a predetermined division line. You It is intended.

[0006]

In the method for manufacturing a semiconductor package of the present invention, the semiconductor chip is mounted on each of the divided regions of the base substrate, and then the simple mold for resin sealing is attached to the chip mounting surface side of the base substrate to obtain the chip. A resin injection space is secured on the mounting surface side. Further, in the subsequent resin sealing, by using a liquid resin which has been filtered by a foreign matter removing filter in advance, it is possible to prevent foreign matter from entering the resin sealing portion.
Furthermore, by injecting the resin in a vacuum atmosphere, the gas contained in the resin escapes due to the vacuum defoaming effect, and the generation of voids in the resin sealing portion is suppressed. After the resin sealing, a plurality of semiconductor packages can be obtained at the same time by cutting the base substrate along a predetermined dividing line with the simple mold removed from the base substrate.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method of manufacturing a semiconductor package according to the present invention is a method in which, for example, a glass epoxy substrate or a ceramic substrate is divided into a plurality of regions, and each of the divided regions has an external surface on the side opposite to the chip mounting surface. A semiconductor package is manufactured using a base substrate having connection terminals,
The procedure will be described in detail below.

First, in the first step, as shown in FIG. 1, the base substrate 1 having a rectangular shape in plan view is divided into nine areas in a grid pattern, and the divided areas on the chip mounting surface 1a side are divided into respective areas. Then, the semiconductor chip 2 divided into individual pieces from a wafer (not shown) is bonded by a die bonding material. Next, the chip-bonded base substrate 1 is supplied to a wire bonding apparatus, and the semiconductor chip 2 bonded to each of the divided regions and the conductor pattern on the substrate side are electrically connected by a wire 3 such as a gold wire. To do. As a result, the individual semiconductor chips 2
Is a pin-shaped external connection terminal 4 provided on the side opposite to the chip mounting surface 1a via the wire 3, the conductor pattern on the substrate side, and the through hole provided on the base substrate 1.
It becomes a state of continuity with.

As a mounting form of the semiconductor chip 2 on the base substrate 1, in addition to the above-mentioned wire bonding method, for example, bumps are formed on the electrode portions of the semiconductor chip 2 and face down to the substrate side. A flip chip method of connecting to a conductor can also be adopted. Further, as the form of the external connection terminal 4 provided on the base substrate 1, a spherical terminal such as a solder ball applied to a BGA (ball grid array) can also be adopted.

Next, in the second step, as shown in FIG. 2, a simple mold 5 for resin sealing is attached to the chip mounting surface 1a side of the base substrate 1. This simplified type 5 is a base substrate 1
A frame body that follows the outer shape of the above, and at the time of its molding, one that has a high release effect for the chip sealing material described later, for example, if the chip sealing material is an epoxy resin or an acrylic resin, a silicon resin or the like is molded. Used as a material. Further, in the second step, after the simple mold 5 is attached to the base substrate 1, the transparent plastic plate 6 is covered on the simple mold 5 to bring them into close contact with each other. As a result, the chip mounting surface 1 of the base substrate 1
A resin injection space is secured by the simple mold 5 and the plastic plate 6 on the a side.

Subsequently, in the third step, as shown in FIG. 3, the base substrate 1 with the simplified mold 5 is set in a vertically standing state in a vacuum chamber 7 and a valve provided in an exhaust system. 8
And the inside of the vacuum chamber 7 is kept in a vacuum atmosphere by the evacuation action of the vacuum pump 9. In this state, the resin supply system valve 10 is opened and the liquid resin 12 is sent out from the resin supply section 11. As a result, the resin 12 delivered from the resin injection section 11 is injected into the simplified mold 5 through the resin injection hole 5a provided in the side wall of the simplified mold 5. At this time,
With the injection of the resin 12, the internal gas of the simplified mold 5 is discharged from the vent hole 5b provided on the opposite side of the resin injection port 5a.

In this embodiment, a liquid resin having a low viscosity is adopted as the resin 12 used for the resin encapsulation, and a foreign matter removing filter is used by using, for example, the filtering device 20 shown in FIG. The foreign matter is removed by a (membrane filter or the like) 21, and the recovered material is supplied from the resin supply section 11 to the resin case 23 through the receiving member 22. In addition, the resin 1 collected in the resin case 22
Since 2 may contain a large amount of gas, the resin case 22 was once left in a vacuum atmosphere and degassed by the vacuum defoaming effect.

When injecting such a resin, the vacuum chamber 7
Since the inside of the resin is kept in a vacuum state by the evacuation action of the vacuum pump 9, the resin 1 discharged from the resin injection port 5a
2 is naturally sucked up by the vacuum force. for that reason,
It is possible to smoothly fill an appropriate amount of the resin 12 into the inside of the simple mold 5 serving as the resin injection space. In addition, since the resin 12 is injected in a vacuum atmosphere, the gas contained in the resin 12 is boiled out of the resin surface due to the vacuum defoaming effect, so that the generation of voids in the resin sealing portion is effectively suppressed. You can Furthermore, since the liquid resin 12 that has been filtered by the foreign matter removing filter 21 is used in advance, it is possible to reliably prevent foreign matter from entering the sealing resin portion.

Further, in the third step, the resin 12 injected into the simple mold 5 is thermally cured by the heating action of the heater 13 installed in the vacuum chamber 7. The heat treatment by the heater 13 may be performed simultaneously with the resin injection, or may be performed separately after the resin injection. By the way, when an ultraviolet curable resin is used for the chip sealing material, the injected resin is cured by irradiating the plastic plate 6 with ultraviolet rays. As a result, the individual semiconductor chips 2 mounted on the base substrate 1 are collectively resin-sealed.

Thereafter, in the fourth step, as shown in FIG. 5, the simple mold 5 used for resin sealing is removed from the base substrate 1 together with the plastic plate 6, and then the division line (broken line) shown in FIG. Along the way, the base substrate 1 after resin sealing is cut. As a result, as shown in FIG. 6, the resin-encapsulated semiconductor package in which the semiconductor chip 2 mounted on the substrate 1 is encapsulated with the resin 12 is solidified, so that the single base substrate 1 Thus, a plurality (9 in the illustrated example) of semiconductor packages can be obtained at the same time.

When the resin is sealed in the third step, the base substrate 1 is set horizontally in the vacuum chamber 7,
It is not always necessary to use the plastic plate 6 by supplying the resin from above the simplified mold 5, but the plastic plate 6 allows the resin to be naturally sucked up in a vacuum atmosphere so that the filling can be smoothly performed. It is more preferable because the package surface is finished accurately and smoothly. Although a glass substrate can be used instead of the plastic plate 6, it is preferable to use the plastic plate 6 in consideration of the followability to heat shrinkage.

Further, in the fourth step, the plastic plate 6 is removed together with the simplified mold 5. However, if there is no possibility of adversely affecting the device characteristics, the plastic plate 6 is attached to form the final product form. It is also possible.

[0018]

As described above, according to the present invention,
By injecting liquid resin that has been filtered by a foreign matter removal filter in advance into a simple mold mounted on a chip-mounted base substrate in a vacuum atmosphere, it is possible to ensure that foreign matter is mixed in and voids are created in the resin encapsulation part. Can be suppressed. Further, after the simple mold is removed from the base substrate after resin sealing, the base substrate is cut along a predetermined division line, so that a plurality of semiconductor packages can be simultaneously obtained from a single base substrate. As a result, particularly when manufacturing a semiconductor package related to an optical device, it is possible to provide a manufacturing method excellent in productivity while avoiding adverse effects on the device characteristics due to inclusion of foreign matter and generation of voids. Furthermore, in carrying out the present invention, since a simple mold can be obtained at low cost by molding, the equipment cost is low and high productivity can be obtained, and further, contamination of foreign matters and generation of voids in the resin sealing portion are suppressed. As a result, the process yield is also improved, and the manufacturing cost of the semiconductor package can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a first step of a package manufacturing method according to the present invention.

FIG. 2 is a diagram illustrating a second step of the package manufacturing method according to the present invention.

FIG. 3 is a diagram illustrating a third step of the package manufacturing method according to the present invention.

FIG. 4 is a configuration diagram of a filtering device used for removing foreign matter.

FIG. 5 is a view (No. 1) for explaining the fourth step of the package manufacturing method according to the present invention.

FIG. 6 is a view (No. 2) explaining the fourth step of the package manufacturing method according to the present invention.

[Explanation of symbols]

 1 base substrate 2 semiconductor chip 4 external connection terminal 5 simple type 12 resin

Claims (1)

[Claims] 1. A method of manufacturing a semiconductor package, comprising: a base substrate which is divided into a plurality of regions and has external connection terminals on a surface opposite to a chip mounting surface corresponding to each of the divided areas, A first step of mounting a semiconductor chip on each of the divided regions of the base substrate, a second step of mounting a simple mold for resin sealing on the chip mounting surface side of the base substrate, and a filter for removing foreign matter in advance A third step of injecting a liquid resin into the inside of the simple mold in a vacuum atmosphere, and curing the injected resin to collectively seal the individual semiconductor chips mounted on the base substrate with a resin; A fourth step of removing the simple mold from the base substrate and then cutting the resin-sealed base substrate along a predetermined dividing line. Manufacturing method.