JPH08340076A - Semiconductor device - Google Patents

Abstract

PURPOSE: To suppress the formation of cavities and development of warps, cracks, etc., by burying a thermosetting synthetic resin which does not remelt until the surface of the resin becomes flush with the front ends of inner leads in the surface of a semiconductor chip between the front ends of adjacent inner leads. CONSTITUTION: A rectangular semiconductor chip 12 is formed of a silicon semiconductor substrate. A plurality of inner leads 13 arranged along the long side of the chip 12 is fixed to the upper surface of the chip 12. The leads 13 are made of Cu or an Ni-Fe alloy and arranged at 0.1-3.0mm intervals. For fixing the front end sections 13a of the leads 13 to the upper surface of the chip 12, a polyimide adhesive tape 14 is used. The front end sections 13a are respectively connected to pads 15 through bonding wires 16. A burying agent 17 composed of a thermosetting resin is buried and a package 18 is formed by injection-molding a synthetic resin for setting and sealing. Therefore, the development of cavities and cracks can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and is particularly suitable for a resin-sealed semiconductor device having inner leads fixed to the surface of a semiconductor chip.

[0002]

2. Description of the Related Art Conventionally, in a LOC (Lead On Chip) type semiconductor device in which an inner lead is fixed on the surface of a semiconductor chip and sealed in a synthetic resin package, the inner lead is formed in a substantially central portion of the semiconductor chip. Since the pad is connected to the pad by the bonding wire, the width dimension of the pad can be made larger than that of the pad provided in the peripheral portion of the semiconductor chip.
It is configured as shown in a plan view of a semiconductor chip having inner leads fixed thereto.

In FIGS. 3 and 4, 1 is a resin-sealed semiconductor device, and 2 is a rectangular semiconductor chip. Reference numeral 3 denotes a plurality of inner leads adhered to the upper surface of the semiconductor chip 2 via an adhesive tape 4, and the inner leads 3 are arranged along a long side of the semiconductor chip 2 with a predetermined interval therebetween, and their tips are provided. Extend to the vicinity of the central portion of the semiconductor chip 2.
The inner lead 3 has a corresponding pad 5 arranged in the long side direction at the tip portion and the substantially central portion of the semiconductor chip 2.
And are connected by a bonding wire 6.

A package 7 is formed by injection molding the semiconductor chip 2 to which the inner leads 3 are bonded by injection molding with a synthetic resin material for sealing. The package 7 has a thickness of about 1 mm, while the semiconductor chip 2 has a thickness of about 0.3 mm and the inner leads 3 have a thickness of about 0.1 mm.

In the semiconductor device 1 thus constructed,
The semiconductor chip 2 to which the inner leads 3 are adhered is held in the molding die of the package 7, and the synthetic resin material for sealing in a molten state, which is heated and pressure-injected from the gate portion of the molding die to the inside of the die, is the semiconductor chip. The package 7 is molded by flowing and solidifying both surfaces of No. 2.

[0006] However, the package 7 has internal cavities in a state of being sealed inside the package 7 or external cavities that are partially open to the outside, or a synthetic resin material for sealing injected into a molding die at the time of molding. Flow of the semiconductor chip 2 may cause problems such as ups and downs of the semiconductor chip 2 such that good molding cannot be performed, and further, warpage or cracks of the package 7 may adversely affect the reliability of the semiconductor device 1. It was.

The cause of these internal cavities and external cavities was investigated, and it was found that the synthetic resin material for sealing in the molten state flows unevenly on both upper and lower surfaces of the semiconductor chip 2 when the package 7 is molded. It has become clear that this is caused by. That is, the synthetic resin material for sealing in a molten state flows relatively smoothly on the lower surface side of the semiconductor chip 2 to which the inner leads 3 of the semiconductor chip 2 are not bonded, but on the upper surface side from the long side portion to the vicinity of the central portion. The flow of the inner leads 3 extending to the upper end prevents the flow from being smooth, and it becomes difficult for the inner leads 3 provided at a predetermined interval to flow on the surface of the semiconductor chip 2. The inner nest and the outer nest are formed due to the part that becomes

Then, the conductive portion and the outer surface are communicated with each other through the inner cavity or the outer cavity, or the stored moisture expands in the inner cavity or the like to generate cracks. Further, the flow of the synthetic resin material for sealing in a molten state is relatively smooth on the lower surface side of the semiconductor chip 2 and not smooth on the upper surface side, so that the semiconductor chip 2 rises and falls due to the difference in flow velocity between the upper and lower surfaces. Will end up. Further, if the unfilled state of the synthetic resin material for encapsulation occurs on the upper surface side, the amount of thermal expansion of the package 7 on the upper and lower surface sides of the semiconductor chip 2 does not become a predetermined amount, and the whole warps.

[0009]

When molding a package as described above, the molten synthetic resin material for sealing does not flow smoothly on the upper surface side of the semiconductor chip to which the inner leads are fixed, and the sealing is performed. The unfilled portion of the synthetic resin material for molding may form internal cavities or external cavities in the package, and there is a possibility that the package may be warped or cracked, resulting in low reliability, and the lower surface side that flows relatively smoothly. Due to the difference in flow rate between the semiconductor chip and the semiconductor chip, the semiconductor chip was up and down, and good molding could not be performed. The present invention has been made in view of such a situation, and an object thereof is to provide a highly reliable semiconductor device in which formation of cavities in a package is suppressed and further warpage, cracks, and the like are suppressed. Especially.

[0010]

According to the present invention, there is provided a semiconductor device comprising:
In a semiconductor device in which the tips of inner leads provided at a plurality of predetermined intervals are fixed on the surface of a semiconductor chip and sealed in a synthetic resin package, at least the semiconductor chips between the tips of adjacent inner leads are On the surface,
It is characterized by being sealed with a package after being embedded with a synthetic resin material,
Further, it is characterized in that the filling with the synthetic resin material is performed until it becomes substantially flush with the tip portion of the inner lead, and further, when the synthetic resin material to be embedded forms the package. It is characterized in that it is not re-melted under the molding conditions of No. 1, and the synthetic resin material to be embedded is a thermosetting synthetic resin material.

[0011]

In the semiconductor device configured as described above, a synthetic resin material is embedded between a plurality of inner leads fixed to the surface of a semiconductor chip, and then sealed by a synthetic resin package. Since it is configured, when molding the package to seal the semiconductor chip, the unevenness on the surface side where the inner leads of the semiconductor chip are fixed is eliminated by embedding with a synthetic resin material, and the entire surface is flat. When molding a synthetic resin package, the flow of the material in the mold becomes smooth and the unfilled state of the material disappears, the formation of cavities in the molded package is suppressed, and warpage and cracks occur. The occurrence of such a phenomenon is suppressed and the reliability is improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a sectional view, and FIG. 2 is a plan view of a semiconductor chip to which inner leads are fixed.

In FIGS. 1 and 2, 11 is a resin-sealed semiconductor device, 12 is a rectangular semiconductor chip, and this semiconductor chip 12 has a side of several mm formed by a silicon semiconductor substrate. And the thickness is about 0.3mm
It is of a degree. Further, 13 is a plurality of inner leads fixed to the upper surface of the semiconductor chip 12,
2 are arranged along both long sides and extend until their tips are located near the center of the semiconductor chip 12.

The inner lead 13 is made of a conductive material such as 42 alloy of copper (Cu) or nickel (Ni) -iron (Fe) alloy and has a width of about 0.1 mm to 0.2 mm. An interval of about 0.1 mm to 0.2 mm is provided between the 13 members.
Further, the inner lead 13 is fixed to the upper surface of the semiconductor chip 12 by an adhesive tape 14 of a polyimide insulating film having a thickness of about 0.1 mm on the upper surface of the semiconductor chip 12 and adhesives provided on both sides. It is performed by adhering the tip portion 13a of the.

The tip portion 13a of the inner lead 13 fixed to the upper surface of the semiconductor chip 12 is connected by a bonding wire 16 to a corresponding pad 15 arranged in the long side direction at a substantially central portion of the semiconductor chip 12. There is.

On the upper surface of the semiconductor chip 12 between the tip portions 13a of the adjacent inner leads 13, an embedding material made of a polyimide-based synthetic resin material, a two-component epoxy resin, a silicon resin, a thermosetting resin, or the like. 17
However, it is embedded so that the upper surface of the tip portion 13a of the adjacent inner lead 13 and the embedded surface 17a are substantially aligned with each other. Alternatively, the embedding material 17 is the inner lead 13
Embedding is performed so as to cover the tip portion 13a of the and to make the entire surface after the embedding flat.

The tip portion 13 of the inner lead 13
The semiconductor chip 1 in which the space between a and is filled with the filling material 17.
2 is set in a molding die, and a package 18 having a thickness of about 1 mm is formed by injection molding with a synthetic resin material for sealing such as silicon-containing epoxy resin, and sealing is performed. After the package 18 is formed, the hanging pins for connecting to the frame (not shown) until the package 18 is formed are cut, and the outer leads extending from the package 18 are formed into a predetermined J-shape or the like. ,
The semiconductor device 11 is a single unit.

Since the semiconductor device 11 is configured as described above, when the package 18 is formed and the semiconductor chip 12 is sealed in the forming process, the semiconductor chip 12 is held in the mold of the package 18. Then, the molten synthetic resin material for sealing is pressurized and injected from the gate portion of the mold into the mold. The injected molten synthetic resin material for sealing flows along both the surface of the semiconductor chip 12 to which the inner leads 13 are fixed and the back surface thereof.

As it flows down, the temperature lowers and the synthetic resin material for sealing, which was in a molten state, begins to solidify. At this time, the synthetic resin material for sealing, which flows on the surface side of the semiconductor chip 12 to which the inner leads 13 are fixed, is in a concave-convex state with the tip portions 13a of the inner leads 13 fixed, so that the embedding material 17 is embedded. It will flow along the flattened embedded surface 17a.

For this reason, the synthetic resin material for sealing, which flows on the surface side to which the inner lead 13 is fixed, like the material flowing on the back surface side, has a substantially constant speed so that a speed difference does not occur smoothly on both surface sides. Flowing. As a result, the semiconductor chip 12 does not rise or fall during molding. Further, since the flow of the synthetic resin material for sealing is not disturbed by the unevenness due to the tip end portion 13a of the inner lead 13, there is no possibility of the unfilled state, and it becomes difficult for internal cavities and external cavities to occur. As a result, the package 18 can be molded well. Then, since the unfilled state of the synthetic resin material for sealing disappears, the package 18 is provided on both sides of the semiconductor chip 12.
The thermal expansion amounts of are substantially the same, and the occurrence of warpage is suppressed.

Furthermore, since it becomes difficult for internal cavities and external cavities to occur, the conductive parts of the semiconductor chip 12 and the like excluding the outer leads extending through these cavities do not communicate with the outer surface, In addition, there is no possibility that the moisture occluded in the package 18 will expand due to internal voids or the like and cracks will occur, and the reliability of the semiconductor device 11 will be improved and will be high.

[0022]

As is apparent from the above description, according to the present invention, a synthetic resin material is embedded between a plurality of inner leads fixed to the surface of a semiconductor chip and then sealed by a synthetic resin package. By being configured so as to be stopped, formation of cavities in the package is suppressed, occurrence of warpage and cracks is also suppressed, and reliability is improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a plan view of a semiconductor chip having an inner lead fixed according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a conventional example.

FIG. 4 is a plan view of a semiconductor chip having inner leads fixed according to a conventional example.

[Explanation of symbols]

 12 ... Semiconductor chip 13 ... Inner lead 13a ... Tip part 17 ... Embedding material 18 ... Package

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H01L 23/29 H01L 23/30 B 23/31

Claims (4)

[Claims] 1. A semiconductor device having a plurality of predetermined inner lead tips fixed to the surface of a semiconductor chip and sealed in a synthetic resin package, wherein at least the tips of adjacent inner leads are provided. A semiconductor device characterized in that the surface of the semiconductor chip between the parts is filled with a synthetic resin material and then sealed with the package. 2. The semiconductor device according to claim 1, wherein the burying with the synthetic resin material is performed until it becomes substantially flush with the tip portion of the inner lead. 3. The semiconductor device according to claim 1, wherein the synthetic resin material to be embedded does not remelt under the molding conditions for forming the package. 4. The semiconductor device according to claim 1, wherein the synthetic resin material to be embedded is a thermosetting synthetic resin material.