KR0167440B1 - Semiconductor device - Google Patents

Abstract

The present invention relates to a semiconductor device, which provides a technique for improving the reliability of a semiconductor device, and a technique for improving signal transmission speed and reducing electric noise due to stray capacitance between a semiconductor chip and a lead in a semiconductor device. To provide, a semiconductor chip having a main surface and a back surface opposite to the main surface, a semiconductor chip having an integrated circuit and a plurality of external terminals formed on the main surface, each of the plurality of leads having an inner lead and an outer lead formed integrally with the inner lead A plurality of leads having a portion of each inner lead on the main surface of the semiconductor chip, a plurality of bonding wires electrically connecting the plurality of outer terminals and the inner lead of the plurality of leads, and at least the main surface of the semiconductor chip, the plurality of leads Has a resin body encapsulating the inner lead of the wire and several bonding wires, It was assumed that cotton was exposed in the resin body.

By doing in this way, the reliability of a semiconductor device can be improved, and the effect that the signal transmission speed and the electrical noise can be improved by the stray capacitance between a semiconductor chip and a lead in a semiconductor device can be aimed at.

Description

Semiconductor device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to semiconductor devices, and more particularly, to a technique effective for adapting to a package of a large integrated circuit of high density.

Conventionally, in order to protect a semiconductor chip, the semiconductor chip was molded and sealed with resin. Several methods are used to position and attach the leads on the semiconductor chip prior to performing this encapsulation.

For example, a lead frame having a tab in the center is used. The lead frame is attached and used before being sealed. In this prior art, a method is known in which an electrode pad in the vicinity of a semiconductor chip is connected with a bonding wire to an inner lead corresponding thereto.

A common problem in the semiconductor package according to the prior art is that a crack occurs along the separation line of the mold which is the outlet of the lead wire of the metal lead frame.

Another problem is that the path of intrusion of pollutants in water or environment along the metal lead wire from the outside to the semiconductor chip is relatively short.

Moreover, in the surface mount package, the water contained in the package expands with the heat of solder reflow, so that the so-called reflow cracking problem in which the crack occurs in the package has been serious.

Another problem was that the bonding wires could not be crossed because the bonding wires needed to connect the inner leads to the electrode pads of the semiconductor chip were relatively long and alternately assigned input and output terminals.

Thus, in order to solve the above problem, a plurality of inner leads are adhered with an adhesive through the semiconductor chip and the insulating film on the circuit forming surface of the semiconductor chip, and the inner leads and the semiconductor chip are electrically connected by bonding wires, In a semiconductor device encapsulated with a molding resin, a semiconductor device in which a common inner lead (bus bar inner lead) is provided near the center line in the longitudinal direction of the circuit forming surface of the semiconductor chip is disclosed in Japanese Patent Laid-Open No. 61-241959 (corresponding to European Application No. 0198194).

In addition, as disclosed in Japanese Patent Application Laid-Open No. 60-167454 or Japanese Patent Application Laid-Open No. 61-218139 (corresponding to US application No. 845332), the tab (die pad) on which the chip is mounted is removed and the lead phase is removed. A package structure of a so-called tapless lead frame method is proposed in which a chip is mounted on an insulating film bonded to the chip and a wire is connected to the chip's bonding pad and the lead by wire.

In addition, Japanese Patent Laid-Open Publication No. 59-92556 and Japanese Patent Laid-Open Publication No. 61-236130 furthermore, lead is bonded to the upper surface of the chip with an adhesive (Lead On Chip), and the bonding pad of the chip and the tip of the lead are Package structures for connecting with wires have also been proposed.

According to the above-described package structure in which the lead is arranged on the upper or lower surface of the chip, the lead length in the package can be lengthened, thereby improving the heat resistance and moisture resistance of the package. In addition, since the adhesion between the resin and the lead is improved by removing the tab, the reflow crack resistance is improved. As a result, even an enlarged chip can be accommodated in a package of conventional dimensions. This package structure also has the advantage of reducing the wiring delay since the bonding wire length can be shortened.

However, the present inventors found the following problem as a result of examining the above-mentioned conventional semiconductor device.

That is, the conventional semiconductor device has the following problems.

[1] Although a plurality of internal leads are adhered with an adhesive on the circuit forming surface of the semiconductor chip with the semiconductor chip and the insulating film interposed therebetween, the floating capacity between the internal lead and the semiconductor chip is increased, so that the signal transmission speed is high. There was a problem that the electrical noise was also increased at the same time as the delay was increased.

[2] Since the insulating film has a large area, the moisture absorption amount increases, and when the reflow occurs, the moisture absorbed vaporizes and expands in the package, causing package cracking.

[3] Since polyimide-based resin is used as the insulating material, there is a problem that the moisture absorption amount increases, and the moisture absorbed during reflow evaporates and expands in the package, causing package cracking.

[4] Since the acrylic resin is used as the adhesive material, there is a problem that the adhesive deteriorates due to a pressure cooker test (PCT) or the like, resulting in a decrease in reliability due to problems such as electrical leakage between the leads and corrosion of aluminum electrodes.

[5] Since the polyimide resin coating film for alpha (α) ray countermeasures is not covered on the entire circuit forming surface of the semiconductor chip, there is a problem that an error due to α ray occurs.

[6] Although a common inner lead (bus bar inner lead) is used as a heat sink, since the inner lead is not coated on the entire surface of the element portion having a large heat generating portion, heat dissipation is insufficient in an element of 1 W or more.

[7] Since the area of the insulating film made of the polyimide resin is large, there is a problem that the temperature cycle is weak.

[8] There is a problem in that the productivity is poor because the wire bonding exceeds the common inner lead (bus bar inner lead).

[9] Since the adhesive layer is flexible, it is difficult to set wire bonding conditions, and thus there is a problem that productivity is poor.

[10] Since the workability for attaching the insulating film to the semiconductor chip is poor, there is a problem that the productivity is poor.

The semiconductor chip is only fixed by a part of the inner lead, so that the semiconductor chip is insufficiently fixed. For this reason, there existed a problem that productivity was bad because a semiconductor chip moved at the time of resin encapsulation (molding).

An object of the present invention is to provide a technique capable of improving the reliability of a semiconductor device.

Another object of the present invention is to provide a technique capable of improving the signal transmission speed and reducing the electric noise by the stray capacitance between the semiconductor chip and the lead in the semiconductor device.

Another object of the present invention is to provide a technique capable of improving the heat radiation efficiency of heat generated in a semiconductor device.

Still another object of the present invention is to provide a technique capable of reducing the influence of heat of reflow in a semiconductor device.

It is still another object of the present invention to provide a technique capable of reducing the influence of heat in a temperature cycle in a semiconductor device.

Another object of the present invention is to provide a technique capable of preventing the occurrence of molding defects in a semiconductor device.

Another object of the present invention is to provide a technique capable of reducing parasitic capacitance formed between a chip and a lead in a semiconductor device provided with a package structure in which leads are arranged on the upper or lower surface of the chip.

Another object of the present invention is to provide a technique capable of improving the productivity in a semiconductor device.

Another object of the present invention is to provide a technique capable of improving the moisture resistance in a semiconductor device.

The above and other objects and novel features of the present invention will become apparent from the description and the accompanying drawings.

1 is a partial cross-sectional perspective view of a resin-encapsulated semiconductor device encapsulating a DRAM according to Embodiment 1 of the present invention.

2 is a plane of FIG.

3 is a cross-sectional view taken along the line I-I of FIG.

4 is a layout diagram showing a schematic configuration of a DRAM shown in FIG.

5 is a plan view of the lead frame shown in FIG.

6 and 7 are main cross-sectional views showing the relationship between the inner lead and the semiconductor chip shown in FIG.

FIG. 8 is a sectional view showing a schematic configuration of a resin molded part which is another embodiment of the insulator shown in FIG.

9 is a cross-sectional view taken along the line II-II of FIG.

FIG. 10 is a view showing the bonding portion between the resin molded body of FIG. 8 and the semiconductor chip. FIG.

FIG. 11 is an assembly development diagram showing the relationship between the semiconductor chip, insulator and lead frame shown in FIG.

12, 13 and 14 are views for explaining the properties of the molding resin material.

15 to 19 are diagrams for explaining an optimal package for injecting molding resin of the resin-encapsulated semiconductor device shown in FIG.

20, 21A, 21B, 22A, and 22B are views for explaining the schematic structure of the resin-encapsulated semiconductor device and the manufacturing method thereof according to the second embodiment of the present invention.

23 to 28 are diagrams for explaining the schematic structure of the resin-encapsulated semiconductor device according to the third embodiment of the present invention and a manufacturing method thereof.

FIG. 29 is a partial sectional perspective view showing a schematic configuration of a resin-encapsulated semiconductor device according to a fourth embodiment of the present invention. FIG.

30 is a cross-sectional view showing a state of resin molding before cutting by the V-V line in FIG.

FIG. 31 is a sectional view showing a state before resin molding of the resin-encapsulated semiconductor device of another embodiment in the case of using the flexible, flowable material of FIG.

32 and 33 are cross-sectional views showing a state before resin molding of the resin-encapsulated semiconductor device of another embodiment in the case of using a flexible and flowable material.

34 is a cross-sectional view showing a state before resin molding of the resin-encapsulated semiconductor device of another embodiment in the case of using a flexible, flowable material.

Fig. 35 is a sectional view showing the schematic arrangement of a resin-encapsulated semiconductor device according to a fifth embodiment of the present invention.

36A, 37A, 38A, 39A, 40A, and 41A are plan views of the semiconductor chip of FIG.

36b, 37b, 38b, 39b, 40b, and 41b are the horizontal center lines of FIGS. 36a, 37a, 38a, 39a, 40a, and 41a, respectively. Cut section.

42 is a diagram showing another embodiment of the present invention according to the fifth embodiment.

43 is a partial sectional perspective view showing a schematic configuration of a resin-encapsulated semiconductor device according to a sixth embodiment of the present invention.

44 is a cross-sectional view taken along the line VI-VI of FIG. 43;

45 is a partial sectional perspective view showing a schematic configuration of a resin encapsulated semiconductor device of a modification of Embodiment 6 of the present invention.

46 is a cross-sectional view taken along the line VII-VII of FIG. 45,

FIG. 47 is a partial sectional perspective view showing a schematic configuration of a resin encapsulated semiconductor device of a modification of Embodiment 6 of the present invention;

48 is a cross-sectional view taken along the line VII-VII of FIG. 47;

FIG. 49 is a partial sectional perspective view showing a schematic configuration of a resin encapsulated semiconductor device of a modification of Embodiment 7 of the present invention.

50 is a cross-sectional view taken along the line VII-VII of FIG. 49;

FIG. 51 is a plan view of device arrangement and bonding pad BP of the semiconductor chip of Example 7 of FIG.

FIG. 52 is an overall plan view of a leadframe of Embodiment 7 of FIG. 49;

Fig. 53 is a plan view showing a schematic configuration of a lead frame of a resin-encapsulated semiconductor device of Example 8 of the present invention.

54A, 54B, and 54C are cross-sectional views of the fixing portion of the semiconductor chip of the resin-encapsulated semiconductor device according to the eighth embodiment of the present invention, respectively.

55, 56, and 57 are cross-sectional views showing a state before resin molding of a modification of the resin-encapsulated semiconductor device of Example 8 of the present invention.

58 and 59 are layout views on a semiconductor chip of the resin-encapsulated semiconductor device of Example 9 of the present invention.

60 is a cross-sectional view illustrating a package of a resin-encapsulated semiconductor device according to a ninth embodiment of the present invention.

61 is a perspective view seen from the side of the resin substrate of Example 10, which faces the wiring board.

62 is a cross-sectional view taken along the line VI-XI of FIG. 61;

FIG. 63 is a cross-sectional view of a modification of the resin-sealed semiconductor device of Example 10 of FIG.

64 to 67 are cross sectional views of another modification of the semiconductor device of Example 10 of FIG.

68 and 69 are sectional views showing a state in which the resin-encapsulated semiconductor device of Example 10 of FIG. 61 is mounted on a wiring board.

70 is an overall external perspective view showing a schematic configuration of a resin encapsulated semiconductor device for encapsulating a DRAM according to Embodiment 11 of the present invention.

FIG. 71 is a partial cross-sectional perspective view of FIG. 70. FIG.

72 is a cross-sectional view taken along the line II-XII of FIG. 74 showing a semiconductor device of one embodiment of the present invention.

FIG. 73 is a fragmentary sectional view cut along the line III-III of FIG.

74 is a schematic plan view of the semiconductor device of FIG. 73;

FIG. 75 is a schematic plan view of a semiconductor chip showing a circuit block of the semiconductor device of FIG.

FIG. 76 is a cross-sectional view taken along line XIV-XIV of FIG. 77 showing a semiconductor device according to another embodiment of the present invention.

77 is a schematic plan view of the semiconductor device of FIG.

FIG. 78 is a schematic plan view of a semiconductor chip showing a circuit block of the semiconductor device of FIG.

FIG. 79 is a sectional view showing a major failure of a semiconductor device according to another embodiment of the present invention. FIG.

An outline of typical ones of the inventions disclosed in the present application will be briefly described as follows.

[1] A common internal lead is bonded to the center line in the X or Y direction of the main surface of the semiconductor chip through an insulator electrically insulated from the semiconductor chip, and a plurality of signal internal leads are formed on the main surface of the semiconductor chip. A semiconductor device bonded through an insulator electrically insulated from the semiconductor chip, wherein the inner lead, the common inner lead, and the semiconductor chip are electrically connected by bonding wires, respectively, and sealed with a molding resin, wherein the inner lead is the insulator. The semiconductor device has a gap between the semiconductor chip and the inner lead on the outer lead side at a portion to be joined to the side of the inner lead.

[2] In the above [1], the area occupied by the insulator is at least 1/2 of the semiconductor chip area.

[3] In the above [1], the area in which the insulator and the main surface of the semiconductor chip are joined is the minimum value possible in manufacturing.

[4] In each of the above [1] to [3], the insulator is made of a resin molded body including a part of the inner lead.

[5] In each of the above [1] to [4], the insulator material satisfies at least two of the following various conditions.

(a) Saturated moisture absorption is about the same or less than encapsulation resin.

(b) Dielectric constant is 4. 0 or less in 10 <^3> Pa and normal temperature-200 degreeC.

(c) Barcol hardness (GYZJ934-1) at temperature 200 degreeC is 20 or more.

(d) Uranium and thorium content is 1ppb or less, and soluble halogen element content is extracted in 10ppm or less when it extracts at 120 degreeC for 100 hours.

(e) Good adhesion between semiconductor chip and inner lead.

(f) The coefficient of thermal expansion is 20 × 10 ^-6 / ℃ or less.

(g) In the case of thermoplastic resin, its glass transition temperature is 220 ℃ or higher.

[6] A plurality of inner leads are arranged on the main surface of the semiconductor chip in a state in which they are floated on the main surface of the semiconductor chip, and the semiconductor chip is adhesively fixed at the inner lead portions of the plurality of inner leads that are not energized. A semiconductor device in which an inner lead other than a lead and a semiconductor chip are electrically connected by bonding wires and sealed with a molding resin.

[7] A plurality of inner leads are arranged on the main surface of the semiconductor chip in a state where the main surface of the semiconductor chip floats, and a surface opposite to the main surface of the semiconductor chip is bonded and fixed through an insulator at a portion of the inner lead, And a semiconductor chip are electrically connected by bonding wires and are sealed with a molding resin.

[8] A semiconductor in which a plurality of internal leads are adhered on a main surface of the semiconductor chip through an insulator electrically insulated from the semiconductor chip, and the internal leads and the semiconductor chip are electrically connected by bonding wires and encapsulated with a molding resin. In the apparatus, one end of the heat dissipation lead electrically insulated from the semiconductor chip is provided on the main surface of the semiconductor chip in the central side of the long side of the package, and the other end of the heat dissipation lead is a package of the main surface of the semiconductor chip. It is a semiconductor device extending to the upper part of the exterior.

[9] In the above [8], the other end of the heat dissipation lead extends to the lower part of the outside of the package on the side opposite to the main surface of the semiconductor chip.

[10] In the above [8] or [9], one end of the heat dissipation lead extends to the upper portion of the heat generating portion of the main surface of the semiconductor chip.

[11] A semiconductor in which a plurality of internal leads are adhered on a main surface of the semiconductor chip through an insulator electrically insulated from the semiconductor chip, and the internal leads and the semiconductor chip are electrically connected by bonding wires and encapsulated with a molding resin. In the apparatus, one end of a heat dissipation lead electrically insulated from the semiconductor chip is provided on a surface opposite to the semiconductor chip main surface of the central portion in the longitudinal direction of the package, and the other end of the heat dissipation lead is formed on the semiconductor chip main surface. The semiconductor device extends from the top of the outside of the package to the bottom of the outside of the package on the side opposite to the main surface of the semiconductor chip.

[12] In each of the above [8] to [11], a heat dissipation plate is provided at an external position of the heat dissipation lead.

[13] In each of the above [6] to [12], the common internal lead is arranged near the center line in the X direction or the Y direction of the main surface of the semiconductor chip.

[14] In each of the above [1] to [12], an insulator is coated on the bonding wire.

[15] In each of the above [1] to [6] or [13], a bonding pad in which a bonding wire wired on the main surface thereof and a common internal lead do not cross each other.

[16] In each of the above [1] to [15], the molding resin material has a particle size distribution of 0.01 to 100 µm, an average particle diameter of 5 to 20 µm, and a maximum filling density. It is a resin composition which mix | blended more than 70 weight% (wt%) of substantially spherical inorganic filler which is 0.8 or more.

[17] The resin composition according to the above [16], wherein the molding resin material is a thermosetting resin, and a resin composition using at least one of phenol-curable epoxy resins, resol-type phenol resins and bismaleimide resins as main components.

[18] The molding resin material according to the above [16] or [17], wherein the molding resin material is any one of a resol type phenol resin or a bismaleimide resin, and its molded product has a bending strength of 215 ° C. 3 kgf / mm 2 or more.

[19] The molding resin material as described in [16] to [18], wherein the molding resin material is an inorganic filler having a particle size distribution of 0.01 to 100 µm, an average particle diameter of 5 to 20 µm, and a maximum filling density of 0.8 or more. Substantially spherical molten silica.

[20] The molding resin materials as described in [16] to [19], wherein the molding resin material is an inorganic filler having a particle size distribution of 0.01 to 100 µm, an average particle diameter of 5 to 20 µm, and a maximum filling density of 0.8 or more. Substantially spherical molten silica is blended in an amount of at least 67. 5% by volume (vol%) with respect to the whole composition, and the molded article has a linear expansion coefficient of 1. 4 × 10 ^-5 / ° C. or less.

[21] In each of [16] to [20], the molding resin material is mixed with 10-fold amount of ion-exchanged water and extracted at 120 DEG C for 100 hours, so that the pH of the extract is 3-7 and the electrical conductivity is 200 kPa. / Cm or less, the amount of extraction of halogen ions, ammonia ions and metal ions is 10 ppm or less.

[22] A plurality of inner leads are adhered with an adhesive on a main surface of the semiconductor chip through an insulator electrically insulated from the semiconductor chip, and the inner leads and the semiconductor chip are electrically connected by bonding wires and encapsulated with a molding resin. In the semiconductor device of the present invention, spherical fine particles having a constant particle diameter selected from among thermoplastic resins or thermosetting resins having a softening point higher than the inorganic or the bonding temperature are used as the filler.

[23] In each of [1] to [22], a plurality of internal leads are adhered to each other by an adhesive through an insulator electrically insulated from the semiconductor chip, or floating on the main surface of the semiconductor chip. In a semiconductor device in which the inner lead and the semiconductor chip are electrically connected by bonding wires and encapsulated with a molding resin, wherein the polyimide for? -Ray shielding is applied to the entire circuit forming area other than the bonding pad of the semiconductor chip. An insulating film is formed at a place where the film is covered and at least the tip of the inner lead or the support lead is adhered on the semiconductor chip.

[24] The method of [23], wherein the insulator is a thermosetting resin containing a printable inorganic filler.

[25] The area of the above-mentioned [23] or [24], wherein the insulator occupies at least 1/2 of the chip area.

[26] In each of [23] to [25], a polyimide film is formed on the side opposite to the main surface of the semiconductor chip.

[27] In each of the above [23] to [26], at least a semiconductor wafer is adhered to a solvent-peelable dry film, subjected to a normal exposure and development process, and then coated with a paste-shaped insulator and embedded in a squeegee. And the process of forming the said insulator with high precision by the wafer process including the process of heating and hardening | curing and peeling a film | membrane.

[28] The method of [26], wherein the insulator is formed by exposure and development of a dry film for soldering resist.

[29] A plurality of internal leads are adhered with an adhesive on the main surface of the semiconductor chip through an insulator electrically insulated from the semiconductor chip, and the internal leads and the semiconductor chip are electrically connected by bonding wires and encapsulated with a molding resin. In the semiconductor device, an insulating film is provided on the entire surface or part of the chip closest surface of the semiconductor chip opposing surface of the inner lead.

[30] A plurality of inner leads are adhered with an adhesive on the main surface of the semiconductor chip through an insulator electrically insulated from the semiconductor chip, and the inner leads and the semiconductor chip are electrically connected with bonding wires and encapsulated with a molding resin. In a semiconductor device, a part or the whole of the main surface of the semiconductor chip is covered with a material that is more flexible or fluid than the molding resin so that the material covers a part or the whole of the bonding wire, and the outside thereof is sealed with a resin.

[31] A plurality of inner leads are adhered with an adhesive on the main surface of the semiconductor chip through an insulator electrically insulated from the semiconductor chip, and the inner leads and the semiconductor chip are electrically connected by bonding wires and encapsulated with a molding resin. In the conventional semiconductor device, a part or the whole of the main surface of the semiconductor chip is covered with a bonding resin, and the resin covers a part or the whole of the bonding wire, and the outside thereof is sealed with a molding resin.

[32] The above-mentioned [31], wherein a recess is formed in a part of the outer surface of the molding resin covering the non-circumferential surface side of the semiconductor chip, thereby substantially exposing a part of the semiconductor chip.

[33] In each of [30] to [32], a common internal lead is provided near the center line of the main surface of the semiconductor chip in the X direction or the Y direction.

[34] A plurality of internal leads are adhered with an adhesive on the main surface of the semiconductor chip through an insulator electrically insulated from the semiconductor chip, and the internal leads and the semiconductor chip are electrically connected by bonding wires and encapsulated with a molding resin. In the conventional semiconductor device, a recess or a convex portion is provided on the non-major surface of the semiconductor chip.

[35] A plurality of internal leads are adhered with an adhesive on the main surface of the semiconductor chip through an insulator electrically insulated from the semiconductor chip, and the internal leads and the semiconductor chip are electrically connected by bonding wires and encapsulated with a molding resin. In the semiconductor device, a plurality of grooves are provided on the non-major surface of the semiconductor chip.

[36] A plurality of internal leads are adhered with an adhesive on the main surface of the semiconductor chip through an insulator electrically insulated from the semiconductor chip, and the internal leads and the semiconductor chip are electrically connected by bonding wires and encapsulated with a molding resin. In the semiconductor device, a recess, a convex portion or a plurality of grooves are provided in a state in which a silicon oxide film is left on a surface opposite to the main surface of the semiconductor chip.

[37] A plurality of inner leads are adhered with an adhesive on the main surface of the semiconductor chip through an insulator electrically insulated from the semiconductor chip, and the inner leads and the semiconductor chip are electrically connected by bonding wires and encapsulated with a molding resin. In such a semiconductor device, the distance from the portion of the inner lead bonded to the semiconductor chip to the outer wall of the package is larger than the distance from the side opposite to the main surface of the semiconductor chip to the outer wall of the package.

[38] In each of the above [1] to [37], the bonding pads with the inner leads are mirror-symmetrically provided with two semiconductor chips interposed therebetween with inner leads at the main surface side of the two semiconductor chips. The lead and the bonding pad of the semiconductor chip are electrically connected to each other and sealed with a molding resin.

[39] In each of the above [34] to [38], the common internal lead is arranged near the center line in the X direction or the Y direction of the main surface of the semiconductor chip.

[40] In each of the above [1] to [39], in the resin encapsulated semiconductor device, at least one heat dissipation groove is provided on a surface of the resin encapsulated semiconductor device that faces the mounting substrate. Both ends of A are open toward the outside in the side surface of the semiconductor device.

[41] The method of [40], wherein the second heat dissipation groove is provided on the side opposite to the surface of the semiconductor device in which the heat dissipation groove is provided in the same direction as the heat dissipation groove, and both ends of the second heat dissipation groove are formed in the semiconductor device. It is open toward the outside in the side surface.

[42] The thickness of the molded resin according to the above [41] or [42] on the bottom surface of the heat dissipation groove provided on the surface of the semiconductor device facing the mounting substrate.

[43] In each of the above [40] to [42], the common internal lead is arranged near the center line in the X direction or the Y direction of the main surface of the semiconductor chip.

[44] In each of [40] to [43], the semiconductor device is mounted on a mounting substrate so that mutual heat dissipation grooves are connected to each other.

A semiconductor device is formed by bending a portion of a lead disposed on an upper surface or a lower surface of a chip accommodated in a package outward with respect to an upper surface or a lower surface of the chip.

According to the semiconductor device described in [1], the inner lead has a stepped structure in which the distance between the semiconductor chip on the outer lead side and the inner lead is wider than the distance between the portion bonded to the insulating film at the portion to be bonded to the insulating film. Since the stray capacitance between the chip and the lead is smaller than that of the conventional one, it is possible to improve the signal transmission speed and reduce the electric noise.

According to the semiconductor device according to the above [2], since the area occupied by the insulating film on the main surface of the semiconductor chip is at least 1/2 or less of the chip area, the amount of moisture absorption by the insulating film is reduced, and thus the influence of heat and temperature during reflow. The influence of heat due to the cycle can be reduced. In addition, since the stray capacitance between the semiconductor chip and the lead is smaller than that of the conventional one, it is possible to improve the signal transmission speed and reduce the electric noise.

According to the semiconductor device according to the above [3], since the moisture absorption amount of the insulating film is minimized by setting the area where the insulating film and the main surface of the semiconductor chip are bonded to the minimum value possible for manufacturing, the effect of heat upon reflow. And the influence of heat due to the temperature cycle can be reduced. In addition, since the stray capacitance between the semiconductor chip and the lead is smaller than that of the conventional one, it is possible to improve the signal transmission speed and reduce the electric noise.

According to the semiconductor device according to the above [4], in the resin molded body including a part of the inner lead, the insulator on the main surface of the semiconductor chip is sufficiently floated between the semiconductor chip and the lead by taking the distance between the semiconductor chip and the inner lead sufficiently. Since the capacity is smaller than the conventional one, the signal transmission speed can be improved and the electrical noise can be reduced.

In addition, since the sealing resin (for example, resin) and a material having good matching are selected as the molding resin, peeling between the molding resin and the sealing resin (mold resin) can be reduced. As a result, leakage between internal leads can be prevented.

According to the semiconductor device according to the above [5], an optimum insulator can be selected by the semiconductor element.

According to the semiconductor device described in the above [6], the semiconductor chip is adhered and fixed at the inner lead portion of the plurality of inner leads that are not energized, and the other inner leads are disposed away from (electrically insulated) on the main surface of the semiconductor chip. Thereby, since an insulating film is not used, moisture resistance can be improved. Moreover, the process of adhering an insulating film becomes unnecessary.

According to the semiconductor device described in the above [7], a plurality of internal leads are disposed on the main surface of the semiconductor chip away from (electrically insulated) from the main surface of the semiconductor chip, and the side opposite to the main surface of the semiconductor chip is Since the inner lead is not adhered to the main surface of the semiconductor chip by being fixed to a part of the inner lead via the insulating film, breakage or damage of the main surface of the semiconductor chip can be prevented. In addition, since no insulating film is used on the main surface of the semiconductor chip, the moisture resistance can be improved.

According to the semiconductor device described in [8], one end of the heat dissipation lead electrically insulated from the semiconductor chip is provided at the central portion of the side of the package in the longitudinal direction, and the other end of the heat dissipation lead is the package on the main surface of the semiconductor chip. Since it extends to the upper part of the exterior, the heat radiating efficiency of the heat | fever of the heat generating part of a semiconductor chip can be improved.

According to the semiconductor device according to the above [9], since the other end of the heat dissipation lead according to the above [8] extends to the lower portion of the package outer side on the side opposite to the main surface of the semiconductor chip, the heat dissipation efficiency of heat of the heat generating portion of the semiconductor chip. Can improve.

According to the semiconductor device according to the above [10], since one end of the heat dissipation lead according to the above [9] extends to an upper portion of the heat generating portion of the main surface of the semiconductor chip, the heat dissipation efficiency of heat of the heat generating portion of the semiconductor chip can be improved. .

According to the semiconductor device according to the above [11], one end of the heat dissipation lead according to the above [10] is provided on the side opposite to the semiconductor chip main surface of the central portion in the longitudinal direction of the package, and the other end of the heat dissipation lead. The heat dissipation efficiency of heat of the heat generating portion of the semiconductor chip can be improved because it extends to the upper portion of the package outer side of the semiconductor chip main surface or to the lower portion of the package outer side of the semiconductor chip main surface.

According to the semiconductor device described in [12], since the heat dissipation plate is provided at an external position of the heat dissipation lead as described in each of [8] to [11], the heat dissipation efficiency of heat of the heat generating portion of the semiconductor chip can be further improved. .

According to the semiconductor device according to the above [13], an internal lead (bus bar internal lead) for a common signal line is placed near the center line in the X direction or the Y direction of the main surface of the semiconductor chip according to each of [1] to [12]. Since it is arrange | positioned, it can connect easily in a small area, for example, without shorting bonding wires, such as the reference voltage Vss in a semiconductor chip, the power supply voltage Vcc in a semiconductor chip, and the like. Moreover, the workability of wire bonding can be improved.

According to the semiconductor device described in [14], the insulating wire is coated on the bonding wire according to [13], and thus, a short circuit between the bonding wire for connecting a plurality of signal lines and the semiconductor chip and the inner lead for common signal lines is prevented. can do.

According to the semiconductor device described in [15], the bonding pads (external terminals) do not intersect the bonding wires wired on the main surface of the semiconductor chip according to [14] and the common internal leads (bus bars internal leads). As a result, a short circuit between the bonding wiring wire and the common inner lead for connecting the plurality of signal inner leads and the semiconductor chip can be prevented.

According to the semiconductor devices described in [16] to [21], (a) substantially spherical melting of the particle size distribution of 0.1-100 micrometers, the average particle diameter of 5-20 micrometers, and the maximum filling density of 0.8 or more The encapsulation material made of silica has a lower melt viscosity and better fluidity than the commonly used square melt silica. Therefore, it does not deform the gold (Au) wire or lead during the molding, or let the semiconductor chip flow out. Do not. Moreover, the narrow gap of a package can be filled satisfactorily.

(b) Since the encapsulation material using the spherical molten silica has little influence on the melt viscosity and fluidity of the material, the compounding amount is increased to lower the thermal expansion of the material. Therefore, the package has good crack resistance.

(c) When high purity resol type phenol resin or polyimide resin is used, good reliability can be obtained.

(d) Encapsulation materials using high-purity resol type phenol resins or polyimide resins have high heat resistance of molded articles, especially high temperature mechanical strength. Moisture resistance and thermal shock resistance can be obtained.

According to the semiconductor device according to the above [22], since the spherical particulate filler having a constant particle diameter is blended as the filler in the adhesive according to the above [1] to [21], the gap between the semiconductor chip and the lead is fixed. The diameter can be controlled to be the same as the diameter so that the dispersion of the capacitance between the semiconductor chip and the lead can be reduced.

According to the semiconductor device described in [23], the? -Ray shielding polyimide film is coated over the entire circuit forming region other than the bonding pads of the semiconductor chips described in the above [1] to [21], and at least internal leads are formed on the semiconductor chip. Since the insulating film is formed at the tip or the place where the supporting lead is bonded, the α-ray shielding polyimide film can shield the α line to the whole area of the circuit forming region, and the semiconductor chip is fixed to the semiconductor chip by the insulating film. You can.

In addition, since the insulating film is formed only at the point where the tip of the inner lead or the supporting lead is adhered on the semiconductor chip, the stray capacitance between the semiconductor chip and the inner lead can be reduced.

Further, even if an insulator having a thick film is formed in the wafer process, the wafer is not bent because it is partially formed.

According to the semiconductor device according to the above [24], since the insulating film according to the above [23] is a thermosetting resin containing a printable inorganic filler, a highly precise insulating film layer can be formed in the wafer process.

According to the semiconductor device described in [25], the area occupied by the insulating film described in [23] or [24] is 1/2 or less with respect to the chip area. The influence of heat and the influence of heat due to the temperature cycle can be reduced.

In addition, since the stray capacitance between the semiconductor chip and the lead is smaller than that of the conventional one, it is possible to improve the signal transmission speed and reduce the electric noise.

According to the semiconductor device described in [26], since the polyimide film is formed on the side opposite to the main surface of the semiconductor chip according to each of [22] to [24], cracks caused by heat of reflow are prevented. can do.

According to the semiconductor device according to the above [27], the insulating film described in each of [23] to [26] adheres at least a solvent release type dry film to a semiconductor wafer, and after passing through a normal exposure and development process, a paste-like insulator The insulating film is formed in a high-precision batch process by a wafer process which includes applying, embedding with a squeegee, heating and curing, and peeling off the solvent-peeled dry film, thereby improving productivity.

According to the semiconductor device described in [28], the insulating film described in [26] is formed by the exposure and development of the dry film for soldering resist, so that the productivity can be improved.

According to the semiconductor device described in [29], the insulating film is formed in the lead frame state on the entire surface or a part of the chip closest surface of the semiconductor chip opposite surface to the inner lead on the circuit formation surface of the semiconductor chip, [2] or [ The insulating film between the semiconductor chip and the inner lead described in [3] can be easily provided.

Moreover, the productivity can be improved.

According to the semiconductor device described in [30], a part or the entire surface of the circuit forming surface of the semiconductor chip is covered with a material that is more flexible or fluid than the encapsulation resin (molding resin), and the material covers part or all of the bonding wiring wire. Since the molding resin does not directly contact the bonding wiring wire by covering the outer side with a resin, the bonding wiring wire is repeatedly deformed due to relative thermal deformation between the semiconductor chip and the resin during the temperature cycle. Disconnection can be prevented.

According to the semiconductor device described in [31], a part or the entirety of the main surface of the semiconductor chip is coated with a coating resin, and the resin covers a part or the whole of the wire for bonding wiring, and the outside thereof is sealed with a molding resin, Since the molding resin does not directly contact the bonding wiring wire, it is possible to prevent the bonding wiring wire from being subjected to repeated deformation due to relative thermal deformation between the semiconductor chip and the resin during the temperature cycle, thereby preventing the wire from being disconnected due to fatigue.

According to the semiconductor device described in the above [32], a recess is provided in a part of the outer surface of the molded resin covering the non-circuit forming surface side of the semiconductor chip according to the above [31], thereby substantially exposing a portion of the semiconductor chip to the bonding pad. It is possible to prevent resin cracks during reflow soldering without causing negative moisture resistance and wire breaks during temperature cycles.

Here, the term "substantially" means a case where a thin resin layer which is inevitably broken when a vapor pressure occurs in a thin film of a resin or a package generated on a semiconductor chip surface inevitably in a manufacturing process.

According to the semiconductor device described in [33], a common internal lead (bus bar internal lead) is provided near the center line in the X direction or the Y direction of the main surface of the semiconductor chip according to each of [30] to [32]. This makes it possible to easily wire the wire for bonding wiring such as the reference voltage Vss in the semiconductor chip or the power supply voltage Vcc in the semiconductor chip in a small area. Moreover, the workability of wire bonding can be improved.

According to the semiconductor device described in [34], the corners of the non-circuit forming surface of the semiconductor chip in which the molding resin is constrained to the semiconductor chip and reflow cracks are formed by providing the recess or convex portion in the non-circuit forming surface of the semiconductor chip. Since the stress generated in the negative molded resin portion can be reduced, reflow cracking can be prevented.

According to the semiconductor device described in the above [35], by forming a plurality of grooves in the non-circuit forming surface of the semiconductor chip, the corner of the non-circuit forming surface of the semiconductor chip in which the molding resin is constrained to the semiconductor chip and reflow cracking occurs. Since the stress generated in the negative molded resin portion can be reduced, reflow cracking can be prevented.

According to the semiconductor device described in [36], the silicon oxide (Silicon Oxide) is formed by providing recesses, convex portions, or a plurality of grooves in a state in which a silicon oxide (SiO ₂ ) film is left on the side opposite to the circuit forming surface of the semiconductor chip. Since the adhesion between the SiO ₂ film and the molding resin is strong, peeling of the molding resin on the side opposite to the circuit forming surface of the semiconductor chip can be prevented, and the molding resin is formed by recesses, convexities or a plurality of grooves. Since the stress generated in the molding resin portion of the corner portion of the non-circuit forming surface of the semiconductor chip can be reduced, reflow cracking can be prevented.

According to the semiconductor device described in [37], the distance from the portion bonded to the semiconductor chip of the inner lead to the outer wall of the package is larger than the distance from the side opposite to the circuit forming surface of the semiconductor chip to the outer wall of the package. As a result, the resin average flow velocity of each flow path can be made almost the same, so that generation of voids, bending of the bonding wiring wire, and lack of charge can be prevented. In addition, since the resin flow resistance of each flow path is substantially the same, changes in semiconductor chips and leads can be prevented and high reliability package molding can be realized.

According to the semiconductor device described in [38], two semiconductor chips in which bonding pads with internal leads are mirror-symmetrically formed, and electrode terminals of the internal leads and semiconductor chips with lead frames interposed between the main surfaces of the two semiconductor chips. Since the semiconductor device is electrically connected to the pad and encapsulated with a molding resin, a device having a double capacity can be mounted without changing the external appearance of the package.

According to the semiconductor device described in [39], a common internal lead (bus bar internal lead) is provided near the center line in the X direction or the Y direction of the main surface of the semiconductor chip as described in the above [34] to [38]. This makes it possible to easily wire the wire for bonding wiring such as the reference voltage Vss in the semiconductor chip or the power supply voltage Vcc in the semiconductor chip in a small area. Moreover, the workability of wire bonding can be improved.

According to the semiconductor device according to the above [40] to [42], the heat transfer surface area of the resin-encapsulated semiconductor device can be increased, so that the heat resistance of the resin-enclosed semiconductor device can be reduced.

According to the semiconductor device according to the above [44], the semiconductor device according to each of [40] to [43] is mounted on a mounting substrate so that mutual heat dissipation grooves are connected to each other, thereby providing a heat dissipation groove or a second heat dissipation groove. Since the blowing can be performed in the direction of, each semiconductor device can be cooled efficiently.

According to the semiconductor device described in [45], by forming a portion of the lead outward with respect to the upper surface (lower surface) of the chip, the distance between the chip and the lead can be increased, so that the parasitic capacitance can be reduced.

EMBODIMENT OF THE INVENTION Hereinafter, one Example of this invention is described concretely using drawing.

In addition, in all the figures for demonstrating an Example, the same code | symbol is attached | subjected to the thing which has the same function, and the repeated description is abbreviate | omitted.

Example 1

A resin encapsulated semiconductor device for encapsulating a DRAM according to Embodiment 1 of the present invention is shown in FIGS. do.

As shown in FIG. 1, FIG. 2, and FIG. 3, the DRAM (semiconductor chip) 1 is encapsulated with a resin encapsulated package 2 of SOJ (Small Out-line J-bend) type. The DRAM 1 has a large capacity of 16 [Mbit] x 1 [bit] and has a size of 16.48 [mm] x 8. It consists of a flat rectangular shape of 54 [mm]. The DRAM 1 is sealed in a 400 [mil] resin encapsulated package 2.

A memory cell array and a peripheral circuit are mainly disposed on the main surface of the DRAM 1. The memory cell array will be described in detail later, but a plurality of memory cells (memory elements) for storing 1 [bit] of information are arranged in a matrix form. The peripheral circuit is composed of a direct peripheral circuit and an indirect peripheral circuit. The direct peripheral circuit is a circuit for directly controlling the information write operation or the information read operation of the memory cell. The direct peripheral circuit includes a low address decoder circuit, a column address decoder circuit, a sense amplifier circuit, and the like. The indirect peripheral circuit is a circuit for indirectly controlling the operation of the direct peripheral circuit. The indirect peripheral circuit includes a clock signal generation circuit, a buffer circuit, and the like.

A plurality of internal leads 3A are arranged on the main surface of the DRAM 1, that is, on the surface on which the memory cell array and the peripheral circuit are arranged. An insulating film 4 is interposed between the DRAM 1 and the inner lead 3A to electrically insulate them. The insulating film 4 is formed of polyimide resin, for example. An adhesive layer (not shown) is provided on each of the surfaces of the DRAM 1 side and the inner lead 3A side of the insulating film 4. As the adhesive layer, for example, polyether amide imide resin or epoxy resin is used. This type of resin encapsulated package 2 adopts a lead on chip (LOC) structure in which an inner lead 3A is disposed on the DRAM 1. The resin-encapsulated package 2 employing the LOC structure freely surrounds the inner lead 3A without being restricted by the shape of the DRAM 1, so that the DRAM 1 that is large in size can be encapsulated as much as the surrounding one. have. That is, the resin encapsulated package 2 employing the LOC structure can increase the packing density because the encapsulation size (package size) is reduced even if the size of the DRAM 1 increases due to the increase in capacity.

The inner lead 3A integrally forms one end side with the outer lead 3B, and constitutes a lead with the inner lead portion and the outer lead portion. As for the external lead 3B, a signal applied to each of the external leads 3B is specified and a sign is added thereto. In front of FIG. 1, the front end of the left end is terminal 1, and the front end of the right end is terminal 14. The rear end of the right end (terminal number is indicated by the inner lead (3A)) is terminal 15, and the rear end is terminal 28.

That is, this resin-encapsulated package 2 is comprised of 24 terminals, a total of 1-6 terminals, 9-14 terminals, 15-20 terminals, and 23-28 terminals.

The first terminal is a power supply voltage Vcc terminal. The power supply voltage Vcc is, for example, an operating voltage of the circuit 5 [V]. Terminal 2 is data input signal terminal (D), terminal 3 is empty terminal (NC), terminal 4 is a write enable signal ( ), Terminal 5 is the low address strobe signal terminal ( And terminal 6 is an address signal terminal (A ₁₁ ).

Terminal 9 is the address signal terminal (A ₁₀ ), Terminal 10 is the address signal terminal (A ₀ ), terminal 11 is the address signal terminal (A ₁ ), terminal 12 is the address signal terminal (A ₂ ), and terminal number 13 The terminal is an address signal terminal A ₃ . Terminal 14 is a constant voltage Vcc terminal.

Terminal 15 is the reference voltage Vss terminal. The reference voltage Vss is, for example, a reference voltage 0 [V] of the circuit. The 16th terminal is the address signal terminal (A ₄ ), the 17th terminal is the address signal terminal (A ₅ ), the 18th terminal is the address signal terminal (A ₆ ), the 19th terminal is the address signal terminal (A ₇ ), the 20th terminal The terminal is an address signal terminal A ₈ .

Terminal 23 is address signal terminal (A ₉ ), terminal 24 is empty terminal (NC), terminal 25 is column address strobe signal terminal ( ), Terminal 26 is empty terminal (NC), and terminal 27 is data output signal terminal (Q). Terminal 28 is the reference voltage Vss terminal.

The other end side of the inner lead 3A extends to the center side of the DRAM 1 across the respective long sides of the rectangular shape of the DRAM 1. The tip (tip of the first region) on the other end side of the inner lead 3A is the central portion of the DRAM 1 via the bonding wire (metal thin wire) 5 and in a direction parallel to the long side of the semiconductor. It is electrically connected to several bonding pads (external terminals) BP arranged. The bonding wire 5 uses aluminum (Al) wire. As the bonding wires 5, gold (Au) wires, copper (Cu) wires, and coating wires coated with insulating resin on the surface of the metal wires may be used. The bonding wire 5 is bonded by the bonding method which combined ultrasonic vibration with thermocompression bonding.

The inner lead (Vcc) 3A of each of terminals 1 and 14 of the inner lead 3A is integrally formed, and the central portion of the DRAM 1 is parallel to the long side thereof and according to the outer terminal. Direction (this internal lead (Vcc) 3A is called a common internal lead or busbar internal lead)). Similarly, each of the internal leads Vss 3A of terminals 15 and 28 is integrally formed, and the central portion of the DRAM 1 extends in parallel with its long side (this internal lead Vss ( 3A) is called common internal lead or busbar internal lead). Each of the inner lead Vcc 3A and the inner lead Vss 3A extends in parallel in the region defined by the distal end of the other inner lead 3A.

Each of the internal leads Vcc 3A and the internal leads Vss 3A is configured to supply the power supply voltage Vcc and the reference voltage Vss at any position on the main surface of the DRAM 1. That is, this resin-encapsulated semiconductor device is configured to easily absorb power supply noise and to increase the operating speed of the DRAM 1.

A chip support lead 3C is provided on the rectangular short side of the DRAM 1.

Each of the inner lead 3A, outer lead 3B and chip support lead 3C is cut and molded in the lead frame. The lead frame is made of, for example, a Fe-Ni (for example, Ni content 42 or 50 [%]) alloy, Cu, or the like.

The DRAM (semiconductor chip) 1, the bonding wire 5, the inner lead 3A and the chip support lead 3C are encapsulated with a molding resin 2A which is an encapsulation body. The molding resin 2A uses an epoxy resin to which a phenol-based curing agent, silicone rubber and filler are added in order to reduce stress. Silicone rubber has the effect of reducing the coefficient of thermal expansion at the same time as the elastic modulus of the epoxy resin.

The filler is formed of spherical silicon oxide particles, and similarly has a function of lowering the coefficient of thermal expansion. In addition, an index ID (a cutting part provided at the left ends of FIGS. 1 and 2) is provided at a predetermined position of the package 2.

Next, a schematic configuration of the DRAM 1 encapsulated in the resin encapsulated package 2 is shown in FIG. 4 (chip arrangement diagram).

As shown in FIG. 4, a memory cell array MA area 11 is arranged in almost the entire area of the surface of the DRAM 1 and on both sides of the external terminal. The DRAM 1 of the first embodiment is not limited to this, but the memory cell array is largely divided into four memory cell arrays 11A to 11D.

In FIG. 4, two memory cell arrays 11A and 11B are arranged above the DRAM 1, and two memory cell arrays 11C and 11D are arranged below. Each of these four divided memory cell arrays 11A to 11D is further divided into sixteen memory cell arrays MA11. That is, 64 memory cell arrays 11 are disposed in the DRAM 1. One memory cell array 11 subdivided into 64 has a capacity of 256 [Kbit].

A sense amplifier circuit SA 13 is disposed between two memory cell arrays 11 of the 64 subdivided DRAMs 1. The sense amplifier circuit 13 is composed of a complementary MOSFET (CMOS). The column address decoder circuit YDEC 12 is disposed at one end of each of the memory cell arrays 11A and 11B in the four divided parts of the DRAM 1. Similarly, a column address decoder circuit YDEC 12 is disposed at one end of each of the upper side of the memory cell arrays 11C and 11D.

The word driver circuit WD 14, the low address decoder circuit XDEC 15, and the unit mat control circuit are provided at one end of each of the memory cell arrays 11A and 11C of the DRAM 1 divided into four. Each of 16) is arranged in order from left to right. Similarly, at one end of each of the left side of each of the memory cell arrays 11B and 11D, each of the word driver circuit 14, the low address decoder circuit 15, and the unit mat control circuit 16 are sequentially turned from right to left. It is arranged.

Each of the sense amplifier circuit 13, the column address decoder circuit 12, the word driver circuit 14, and the low address decoder circuit 15 constitutes a direct peripheral circuit among the peripheral circuits of the DRAM 1. This direct peripheral circuit is a circuit for directly controlling the memory cells arranged in the subdivided memory cell array 11 of the memory cell array 11.

The peripheral circuit 17 and the external terminal (between each of the memory cell arrays 11A and 11B and each of the memory cell arrays 11C and 11D of the four divided DRAMs 1) Bonding pad) BP is disposed. As the peripheral circuit 17, a main amplifier circuit 1701, an output buffer circuit 1702, a substrate potential (V _BB ) generation circuit 1703 and a power supply circuit 1704 are disposed, respectively. A total of 16 main amplifier circuits 1701 are arranged in four units. In total, four output buffer circuits 1702 are disposed.

The external terminal BP comprises the resin-encapsulated semiconductor device 2 in a LOC structure, and extends the inner lead 3A to the center of the DRAM 1, and thus is disposed at the center of the DRAM 1. The external terminal BP is arranged from the upper end side to the lower end side of the DRAM 1 in the region defined by the memory cell arrays 11A and 11C, 11B and 11D. Since the signal applied to the bonding pad (external terminal) BP has been described in the resin encapsulated semiconductor device 2 shown in FIG. 4, the description thereof is omitted. Basically, since the internal lead 3A to which each of the reference voltage Vss and the power supply voltage Vcc is applied extends from the upper side to the lower side on the surface of the DRAM 1, the DRAM 1 has an extension along its extension direction. Multiple external terminals BP for the reference voltage Vss and the power supply voltage Vcc are arranged. In other words, the DRAM 1 is configured to sufficiently execute the respective power supply of the reference voltage Vss and the power supply voltage Vcc. Each of the data input signal D, the data output signal Q, the address signals A _{0 to} A ₁₁ , the clock signal and the control signal are concentrated in the central portion of the DRAM 1.

Peripheral circuits 18 are disposed between the memory cell arrays 11A and 11C among the four divided ones of the DRAM 1 and between each of the 11B and 11D. On the left side of the peripheral circuit 18, a low address strobe (RE) circuit 1801, a write enable (W) circuit 1802, a data input buffer circuit 1803, and a limiter circuit 1804 for a power supply voltage (Vcc) ), The X address driver circuit (logic stage) 1805, the X series redundant circuit 1806, and the X address buffer circuit 1807 are disposed. On the right side of the peripheral circuit 18, the column address strobe (CE) circuit 1808, the test circuit 1809, the VDL limiter circuit 1810, the Y address driver circuit (logic stage) 1811, the Y system redundant circuit 1812, each of the Y address buffer circuits 1813 is disposed. In the center of the peripheral circuit 18, a Y address driver circuit (drive end) 1814, an X address driver circuit (drive end) 1815, and a mat selection signal circuit (drive end) 1816 are disposed, respectively.

The peripheral circuits 17 and 18 (also including 16) are used as indirect peripheral circuits of the DRAM 1.

Next, the lead frame will be described in detail.

As shown in FIGS. 1 and 5 (lead frame overall plan view), the lead frame of the first embodiment is provided with twenty signal inner leads 3A ₁ and two common inner leads 3A ₂ . This inner lead 3A (signal inner lead) 3A ₁ and the common inner lead 3A ₂ are formed as shown in FIGS. 3 and 6 (main part cross-sectional view) of the inner lead 3A. The distance (distance) between the portion of the external lead 3B side (the second region of the inner lead portion) and the semiconductor chip 1 in the portion (first region of the inner lead portion) that adheres to the insulating film (insulator) 4 is insulated. It has a stepped structure that is larger than the distance between the portion (first region) and the semiconductor chip 1 bonded to the film formation 4. As described above, the stepped structure of the inner lead 3A including the first region and the second region, which are disposed on the main surface of the semiconductor chip 1, provides a floating capacity between the semiconductor chip and the lead. Since it is smaller than that, it is possible to improve the signal transmission speed and reduce the electric noise.

In addition, adhesion of the main surface of the semiconductor chip 1 to the insulating film 4 and adhesion of the insulating film 4 to the inner lead 3A are carried out by the adhesive 7 as shown in FIG. In addition, the adhesive 7 is not used for bonding the main surface of the semiconductor chip 1 and the insulating film 4, as shown in FIG. 7, but only for the bonding of the insulating film 4 and the inner lead 3A. Also good.

The above-described effects can be obtained even when the inner lead 3A is applied to a package in which the common inner lead 3A ₂ is not provided.

Also, as shown in Figs. 1 and 5 at a predetermined position of the lead frame, an unenergized chip support lead (supporting lead) 3C for adhesively fixing the main surface of the semiconductor chip 1 is provided. Is provided.

Thus, by fixing and fixing the main surface of the semiconductor chip 1 by the support lead 3C which is not energized, the semiconductor chip 1 is firmly fixed, so that the reliability and moisture resistance of the semiconductor device can be improved. have.

Next, the insulating film 4 will be described in detail.

The area occupied by the insulating film 4 on the main surface of the semiconductor chip 1 is at least 1/2 or less of the area of the main surface of the semiconductor chip 1. In this way, the amount of moisture absorbed by the insulating film 4 is reduced by reducing the area occupied by the insulating film 4 to at least one half of the area of the semiconductor chip 1, and thus, during reflow. The influence of heat and the influence of steam generated by heat by the temperature cycle can be prevented. That is, since generation | occurrence | production of a crack of a package, etc. can be prevented, the reliability of a semiconductor device can be improved.

In addition, since the stray capacitance between the semiconductor chip 1 and the lead is smaller than that of the conventional one, it is possible to improve the signal transmission speed and reduce the electric noise.

In addition, the above-mentioned result can be made more remarkable by making the area which joins the said insulating film 4 and the main surface of the semiconductor chip 1 into the minimum value which can be manufactured. In addition, since an insulating film (insulating film) is used only in a portion of the inner lead that adheres to the semiconductor chip, leakage between the leads can be reduced.

In addition, instead of the insulating film 4 on the main surface of the semiconductor chip 1, as shown in FIG. 8, a resin molded body 6 including a part of the inner lead 3A is used. The distance between the inner lead 3A and the inner lead 3A may be sufficiently large to reduce the stray capacitance between the semiconductor chip 1 and the inner lead 3A.

By doing in this way, since the resin molding 6 and the molding resin (for example, resin) 2A are formed of a material with good compatibility, peeling between peeling interface leads can be reduced.

The resin molded body 6 and the semiconductor chip 1 may be bonded by the adhesive 7 as shown in FIG.

Examples of the base materal and the resin molded body 6 of the insulating film 4 include epoxy resins, BT (bismaleimide triazine) resins, phenol resins (such as resol type), polyimide resins (ether bonds and carbonyls). One or more resins selected from an aromatic polyimide containing a bond, a cycloaliphatic polyimide, and the like) are used as the main component, and an inorganic filler, a fiber hardening agent, various additives, and the like are added thereto as necessary.

In addition, examples of the base material of the insulating film 4 and the material of the resin molded body 6 include alicyclic polyimide, polyester, polysulfone, aromatic polyetheramide, aromatic polyesterimide, polyphenylene sulfide, and polyamide. Thermoplastic resins such as imides and modified substances thereof, polyether ether ketones, polyether sulfones, and polyetheramide imides are formed as main components, and inorganic fillers, fibers, and additives are added thereto as needed.

As the adhesive for bonding the insulating film 4 or the resin molded article 6 to the inner lead 3A and the semiconductor chip 1, an epoxy resin, a BT resin, a phenol resin (such as a resol resin), and a polyimide resin Thermoplastic resins such as thermoset resins or aromatic polyetheramides, polyether ether ketones, polysulfones, aromatic polyester imides, polyesters, and alicyclic polyimides modified using a plurality of isomerane resins, silicone resins and resins thereof You can choose from.

In the case of surface-mount integrated circuits such as SOJ, when soldering to a printed circuit board (PCB), vapor-phase reflow solder method or infrared reflow soldering method is used. In this case, moisture absorption in the package is used. At this reflow temperature (215-260 degreeC), it may expand and peel, and the adhesion | attachment of a chip | tip interface may peel off, the internal pressure of a peeling surface rises, and sealing resin may crack.

In the LOC structure, since the inner lead 3A and the semiconductor chip 1 are joined by the insulating film 4 or the resin molded body 6, the LOC structure is described in detail by the moisture absorption of the insulating film 4 or the resin molded body 6 itself. Accelerate one phenomenon. Therefore, in order to reduce this, it is effective to make the volume of the insulating film 4 small and to reduce the moisture absorption amount.

The lower limit of the bonding area is an area that can withstand the external force received in the processes of wire bonding and resin (resin) molding (sealing).

Here, the material properties of the insulator of the insulating film 4 or the resin molded body 6 will be examined.

A junction insulating material between the internal lead 3A and the semiconductor chip 1 in a LOC-structured semiconductor device or a semiconductor device having a chip on lead (COL) structure, which satisfies at least two of the following seven items. Use materials to make

[1] The saturated moisture absorption is about the same or less than the encapsulating resin.

This is effective for preventing resin cracking in VPS (Vapor Phase Solder).

[2] The dielectric constant is 4. 0 (at 10 ³ Pa, at room temperature to 20 ° C) or less.

This reduces the stray capacitance between the inner lead and the semiconductor chip.

[3] Bacol hardness at 200 ℃ is 20 or more.

This improves wire bondability.

[4] Soluble halogen element content of 10 ppm or less when content of U and Th is 1 ppb or less and extracted at 120 degreeC for 100 hours.

This is effective for preventing software errors and improving moisture resistance.

[5] Good adhesion between semiconductor chip and inner lead.

This secures wire bond resistance, improves moisture resistance, and leaks current between inner leads.

[6] The coefficient of linear thermal expansion is less than 20 × 10 ^-6 / ℃.

This reduces the warp when the insulating material is bonded to the inner lead 3A, and improves the workability of joining the semiconductor chip in the next step.

[7] In the case of thermoplastic resin, glass transition temperature Tg is 220 ℃ or higher.

This is because the glass transition temperature Tg is thermally deformed at a material of 220 ° C. or lower at a high temperature (215 ° C.) at the time of reflow soldering, so that package cracking is likely to occur.

Embodiments of materials satisfying at least two of the above seven items will be described.

For example, both sides of Kafton (Polyimide Film from DuPont) 500H or Eupyrex S (Polyimide Film from Ubekosan) are roughened, and both sides have a glass transition temperature Tg of 220 or more. The membrane coated with ether amide at 25 μm is a material that satisfies the conditions except for [1].

Epoxy resins, resol resins, isomelamine resins, phenol-modified epoxy resins and epoxy-modified polyimides on both surfaces of a bismaleimide film or epoxy film made of high purity quartz fiber or aramid fiber as a reinforcing material or an epoxy-modified polyimide film 125 μm. The adhesive selected from the mid resin is coated with 10 to 25 µm, and the dried film is a material satisfying the above items [1] to [6].

In addition, Teflon PFA (tetrafluorinated ethylene-perfluoro alkoxy copolymer made by Dupont) or Teflon EFP (tetrafluorinated ethylene-per6 fluorinated propylene copolymer made by Dupont) or capton F type (Toray Co., Ltd.) DuPont Co., Ltd., a material coated with Teflon FEP on both sides of the capton film) to improve adhesion to the both sides of the film by a plasma treatment method, and epoxy resin, resol resin, aromatic polyetheramide resin, and polyimide on both sides. In the film coated with the adhesive selected from the precursor and the like, all of the above items are satisfied, and the moisture absorption and the dielectric constant are particularly small.

Next, a method of bonding and fixing the semiconductor chip 1 using an adhesive with the insulating film 4 interposed in the lead frame 3 will be described.

As shown in FIG. 11 (exploded view showing the relationship between the lead frame 3, the insulating film 4, and the semiconductor chip 1), the signal inner lead 3A _{1 on the main} surface of the semiconductor chip ₁ is shared. The insulating film 4 is divided on the position opposite to each of the inner lead 3A ₂ and the supporting lead 3C, and bonded by an adhesive 7 (FIGS. 1 and 6). Next, as shown in FIG. 6, the signal inner lead 3A ₁ , the common inner lead 3A ₂ , and the support lead 3C of the lead frame 3 are fixed by the adhesive agent 7. .

An embodiment of the molding resin material (resin) will be described next.

[1] A thermosetting resin comprising a substantially spherical inorganic filler having a particle size distribution of 0.01 to 100 µm, an average particle diameter of 5 to 20 µm, and a maximum filling density of 0.8 or more, by 70% by weight or more [wt%] Resin compositions are used.

The resin component in this case may be any of epoxy, resol and polyimide.

Thus, the molding resin material using the spherical inorganic filler (e.g., molten silica) is formed as shown in FIG. 12 (showing the relationship between the filling density of the filler (filler) and fluidity). Since there is little influence on melt viscosity and fluidity, the compounding amount can be increased to achieve low thermal expansion of the material. In addition, as shown in FIG. 13 (a diagram showing the relationship between the amount of filler blended and the physical properties of the molded article) and FIG. Can be reduced. Therefore, a package becomes favorable crack resistance.

In particular, it is possible to prevent deformation or damage to the device in the case of molding a semiconductor device having a delicate structure such as a LOC structure.

[2] A resin composition containing at least one of a high-purity phenol-curable epoxy resin, a resol type phenol resin, and a bismaleimide resin is used.

The cured product characteristics when using a crude resol resin are shown in Table 1 (attached at the end of the detailed description of the invention), and the major difference from the genuine product is that the volume resistivity differs more than three digits, especially at 140 ° C. to be. In addition, since there are many ionic impurities, a large difference is also seen in the electrical conductivity of the extract.

In the method for producing the purified resol resin, for example, 500 g of phenol, 550 g of 30% formalin and 5 g of zinc acetate as a curing agent are added to the flask, and gradually heated with stirring, followed by heating at 90 ° C. for 60 minutes while refluxing. Thereafter, the flask was decompressed to 20 mm Hg to remove condensed water and unreacted components.

Next, 300 g of acetone is added to the reaction product to dissolve the reaction product, and pure water is further added, followed by vigorous stirring at 50 ° C. for 30 minutes.

After cooling, the upper moisture layer was removed, and the reaction product was again melted in 300 g of acetone, and again pure water was added and then stirred by cooling at 50 ° C. for 30 minutes, and then the upper moisture layer was removed. This washing operation is repeated five times. For each washing, a part of the reaction product is extracted, dried at 40 ° C. for 48 hours under reduced pressure, and six kinds of resol type phenol resins having different degrees of purification are obtained.

Purification number of the resol-type phenolic resin thus obtained, melting point of resin, curing characteristics, 50 g of pure water was added to 5 g of these resol-type phenolic resin, and the hydrogen ion concentration (pH) of the extracted water after heating at 120 ° C for 120 hours The analysis results of the conductivity and the extracted ionic impurity concentration are summarized in Table 2 (attached at the end of the detailed description).

As is apparent from Table 2, it can be seen that the resol-type resin phenol resin which repeated the above-mentioned washing operation five times has very little ion impurity.

As described above, the effects of the purification can improve the moisture resistance reliability of the molded product, the high temperature life of the Au / Al junction, and the improvement of device characteristics.

[3] A high purity resol type phenolic resin or bismaleimide resin as its main component, and its molded product has a bending strength of 215 ° C of 3 kgf / mm 2 or more, for example, Examples 2 and 3 in Table 1. Use of

Thus, the encapsulation material using high-purity resol type phenolic resin or polyimide resin has high heat resistance of the molded article, and the bending strength at 215 ° C is 3 kgf / mm2 or more, so that the package is moisture-absorbed (package crack). Alternatively, the moisture resistance and the thermal shock resistance after reflow are very good.

[4] A substantially spherical particle having a particle size distribution of 0.01 to 100 µm, an average particle diameter of 5 to 20 µm and a maximum filling density of 0.8 or more, as an inorganic filler blended with the base resin of the above [2] or [3]. As melted silica of, for example, any one of Examples 1, 2 and 3 in Table 1 is used.

As described above, the encapsulation material using the spherical molten silica has little influence on the melt viscosity and fluidity of the material, so that the amount of the compound can be increased to achieve low thermal expansion of the material.

Therefore, in addition to the effect of said [2] or [3], a package becomes favorable crack resistance.

[5] The substantially spherical molten silica of which the resin encapsulating material is an inorganic filler with a particle size distribution of 0.01 to 100 µm, an average particle diameter of 5 to 20 µm, and a maximum filling density of 0.8 or more is applied to the entire composition. It is mix | blended with 5 volume percentage [vol%] or more, and a molded article has a linear expansion coefficient of 1. 4 * 10 <^-5> / degreeC or less, For example, any one of Examples 1, 2, and 3 of Table 1 is used.

By doing in this way, the effect of the said spherical molten silica can be made more effective.

[6] When the resin encapsulation material is mixed with 10 times the amount of ion-exchanged water and extracted at 120 ° C. for 100 hours, the pH of the extract is 3-7, the electrical conductivity is 200 μS / cm or less, and the halogen, ammonia and metal ions The extraction amount is 10 ppm or less, for example, any one of Examples 1, 2 and 3 in Table 1 is used.

Next, one experimental example in Examples 1 to 6 of the above resin encapsulating material will be described.

As shown in Table 1, as the thermosetting resin, epoxy resin (conventional example), resol type phenol resin (Example 1) and bismaleimide resin (Example 2) were used as the base resin, and the particle size distribution was used as a filler. 0.1 to 100 µm, a substantially spherical molten silica having an average particle diameter of 5 to 20 µm, a maximum filling density of 0.09, and various additives, and the mixture was heated by a biaxial roll heated to about 80 캜. Three kinds of resin encapsulation materials were prepared by melting and heating for a minute, cooling and pulverizing.

Next, using each resin encapsulation material, a semiconductor device having a LOC structure shown in FIG. 1, that is, 16MDRAM, was formed by a transfer molding machine. Molding was performed at a mold temperature of 180 ° C., transfer pressure of 70 kgf / mm 2, and molding time of 90 seconds.

According to the experimental example, the following effects were obtained.

[1] As a filler, encapsulating materials using substantially spherical molten silica having a particle size distribution of 0.01 to 100 µm, an average particle diameter of 5 to 20 µm, and a maximum filling density of 0.8 or more are generally used square molten silica. Since the melt viscosity is low and the flowability of the material is good, the bonding wire 5 or the lead frame 3 such as Au is not deformed or the semiconductor chip 1 is flowed down during the molding. Narrow gaps were also satisfactorily filled.

[2] Since the spherical molten silica has little influence on the melt viscosity and the fluidity of the material, it is possible to increase the blending amount and to lower the thermal expansion of the material. Therefore, the package had good crack resistance.

[3] As a conventional semiconductor encapsulating material, epoxy resins are used, and phenolic resins and polyimide resins have many ionic impurities, and therefore, they are deteriorated in electrical properties and moisture resistance and have not been put to practical use.

However, when high purity resol type phenol resins and polyimide resins are used, good reliability can be obtained.

[4] Encapsulation materials using high-purity resol type phenolic resins or polyimide resins have high heat resistance and particularly high mechanical strength at high temperatures. Moisture resistance and thermal shock resistance were very good.

Next, the means for preventing generation of voids, bending of bonding wires, shortage of filling, and the like when the resin encapsulating material is injected into a mold will be described.

As shown in FIG. 1, the adhesive 7 is formed on the main surface of the semiconductor chip 1 via an insulating film 4 in which several internal leads 3A electrically insulate the semiconductor chip 1 from each other. In the 16MDRAM bonded to each other by the inner lead 3A and the semiconductor chip 1 electrically connected by the bonding wires 5 and encapsulated with a resin, as shown in FIG. 15 (main cross-sectional view of FIG. 1). As described above, the distance H ₁ from the main surface of the chip bonded to the semiconductor chip 1 of the inner lead 3A to the first outer wall of the package (encapsulation) 2 located on the main surface side of the chip is the circuit of the semiconductor chip. forming surface and is to be an opposite side surface (back surface), the distance larger than the package structure in which H ₂ to the second outer wall of the package (plug) which is located on the back surface of the chip in.

By such a package structure, FIG. 16 (sectional drawing modeling FIG. 15), FIG. 17 (sectional drawing cut by III-III line | wire of FIG. 16), FIG. 18 (IV-IV line | wire of FIG. 16) As shown in the cross-sectional view taken along the line), the depth h ₃₁ and h ₃₂ of the upper flow path of the inner lead 3A, the depth h ₂ of the middle portion of the inner lead 3A and the semiconductor chip 1, and the semiconductor chip ( The relationship of the depth h ₁ of the flow path in the lower part of 1) is represented by following Formula, respectively.

Where h _C is the cavity depth, t _C is the thickness of the chip, t _f is the thickness of the lead frame, W _C is the cavity width, and W _f is the length of the lead frame that emerges from the chip.

The relationship of each of the above equations is graphically shown in FIG. 19.

Thus, the resin flow path of the package 2 is the upper flow path between the first region of the inner lead 3A and the first outer wall, the middle flow path between the second region of the inner lead 3A and the semiconductor chip and the semiconductor chip ( Each flow path ① shown in FIG. 17 by dividing it into three of the lower flow path between 1) and the said 2nd outer wall, and setting the depth and resin flow path structure of each flow path so that the resin average flow velocity of each flow path may become the same. Since the average resin flow rates of, ②, and ③ are the same, it is possible to prevent voids, bending of the bonding wire (gold wire) 5, and insufficient filling.

In addition, since the resin average flow rates of the respective flow paths 1, 2, and 3 are the same, deformation of the semiconductor chip 1 and the internal lead 3A can be prevented, and a highly reliable package can be obtained.

Example 2

The semiconductor integrated circuit value of the second embodiment of the present invention is shown on the main surface of the semiconductor chip 1 of the first embodiment as shown in FIGS. 20, 21a, 21b, 22a, and 22b. The insulating film 4A is provided on the entire surface or a part of the chip closest contact surface on the opposite surface of the attached insulating film 4 to the semiconductor chip ₁ of the signal inner lead 3A ₁ and the common inner lead 3A ₂ . The insulating film 4A includes a protrusion provided on the signal inner lead 3A ₁ and a rectangular film part provided on the common inner lead 3A ₂ . The rectangular film portion is formed toward the direction parallel to the long side of the semiconductor chip, and the protrusion is formed from the rectangular film portion toward the long side of the chip.

That is, the insulating film 4A is, for example, as shown in FIG. 20, in the state of the lead frame 3, the semiconductor chip 1 of the signal inner lead 3A ₁ and the common inner lead 3A ₂ . An insulating film 4A is provided in advance on the entire surface of the surface closest to the semiconductor chip on the side opposite to the main surface of the film, and the insulating film 4A and the semiconductor chip 1 are adhesively fixed by an adhesive during assembly.

The lead frame 3 having the insulating film 4A is formed on, for example, the front surface of the surface closest to the semiconductor chip 1 on the surface opposite to the main surface of the semiconductor chip 1 of the thin plate for one inner lead. The insulating film 4 is bonded and molded and cut by a press or the like to produce the signal inner lead 3A ₁ , the common inner lead 3A ₂ , and the insulating film 4A at once.

In this way, the insulating film 4A is separated into a rectangular film portion and a plurality of protrusions, whereby the area of the insulating film 4A can be reduced. In addition, alignment between the signal inner lead 3A ₁ and the common inner lead 3A ₂ and the insulating film 4A can be performed well. In addition, since the insulating film 4 does not exist between the signal inner lead 3A ₁ and the common inner lead 3A ₂ , leakage between them can be prevented.

In addition, the insulating film 4 can be divided into a plurality of pieces, for example, divided into four pieces, and the effect of stress due to heat can be reduced as compared with the case of the single insulating film 4.

In addition, as shown in FIG. 21A, the signal inner lead 3A ₁ and the common inner lead of the entire surface of the surface (rear surface) closest to the semiconductor chip 1 on the surface opposite to the main surface of the semiconductor chip 1 ( The insulating film 4B can be provided only at the portion corresponding to the bonding portion of 3A ₂ ) and the area occupied by the insulating film 4B with respect to the semiconductor chip 1 can be minimized.

The lead frame 3 having the insulating film 4B having the smallest area occupied by the insulating film 4B with respect to the semiconductor chip 1 is, for example, a signal inner lead 3A as shown in Fig. 21B. ₁ ) and four insulating films 4 provided with holes at predetermined positions are adhered to the entire surface of the common inner lead 3A ₂ closest to the semiconductor chip 1 on the surface opposite to the main surface of the semiconductor chip 1. Then, the mold is cut and cut by a press or the like, and the insulating film 4B is attached only to the positions corresponding to the bonding portions of the signal inner lead 3A ₁ and the common inner lead 3A ₂ .

By doing in this way, since the amount of insulating films can be further reduced further compared with the Example shown in FIG. 20, the moisture absorption amount can be further reduced. In this manner, when the supporting leads are joined together, the semiconductor chip 1 can be easily fixed.

In addition, although the insulating film 4A was provided only in the part corresponding to a bonding part in the Example shown in FIG. 21A, you may partially provide the insulating film 4A in other parts as needed.

In addition, as shown in FIG. 22A, the insulating film also extends so that the common inner lead 3A ₂ and the signal inner lead 3A ₁ extend to intersect the portion of the insulating film 4A shown in FIG. (4C) is provided.

In other words, the rectangular film portion and the plurality of projection portions of the insulating film 4A are connected.

For example, as shown in FIG. 22B, the inner lead 3A having the insulating film 4C has one insulating film 4 provided with a hole b in which only a portion corresponding to the signal inner lead 3A ₁ remains. ) Is cut along the center line in the long side direction of the insulating film 4 and divided into two. The two-divided insulating film 4C is produced by attaching to the common internal lead 3A ₂ and the signal internal lead 3A ₁ .

In this manner, the insulating film 4 is cut in a predetermined pattern in advance to form the insulating film 4C, and only the adhesive film 4C is bonded to the common inner lead 3A ₂ and the signal inner lead 3A ₁ . As a result, the production method of the insulating film 4C is easy. In this manner, the insulating film 4C is attached to the common internal lead 3A ₂ and the signal inner lead 3A ₁ , so that the tip of the signal inner lead 3A ₁ can be flattened, and subsequent steps. Work becomes easy.

Bonding of the insulating film 4C, the common inner lead 3A ₂ and the signal inner lead 3A ₁ is performed by thermocompression in the case of a thermoplastic adhesive, and temporarily fixed in the case of using a thermosetting adhesive. It is joined by executing.

Incidentally, the insulating films 4A, 4B, and 4C shown in Figs. 20, 21A, and 22A may be slightly wider than the width of the inner lead or conversely narrow.

As can be seen from the above description, according to the second embodiment, the amount of the insulating film 4 provided between the semiconductor chip 1, the signal inner lead 3A ₁ and the common inner lead 3A ₂ is lower than that of the conventional one. Since it is very small, even if it maintains for a long time in an environment with high humidity, the amount of moisture absorbed in a semiconductor device can be reduced.

As a result, the underwater pressure in the semiconductor device during the solder reflow process can be reduced, so that a semiconductor device that does not cause resin cracks can be provided.

Example 3

In the semiconductor integrated circuit device according to the third embodiment of the present invention, as shown in FIG. 23, the main surface area of the semiconductor chip 1 other than the bonding pads BP provided on the main surface of the semiconductor chip 1 of the first embodiment. An α-ray shielding polyimide film 8 is coated over the entire surface, and at least the signal inner lead 3A ₁ and the common inner lead 3A ₂ on the main surface of the semiconductor chip 1 (not shown in FIG. 23). The insulating film 4D is formed in the place where the front-end | tip of the is adhere | attached.

The thickness of the α-ray shielding polyimide film 8 is from 2.0 μm to 10. 0 μm.

The film thickness of the insulating film 4D is 75 µm or more. As this insulating film 4D, a thermosetting resin containing a printable inorganic filler is suitable.

The area occupied by the insulating film 4D is at least 1/2 or less of the area of the semiconductor chip 1.

Moreover, the polyimide film 9 is formed in the surface on the opposite side to the main surface of the semiconductor chip 1.

Next, the α-ray shielding polyimide film 8 is coated over the entire main surface area of the semiconductor chip 1 other than the bonding pads BP provided on the main surface of the semiconductor chip 1, and the semiconductor chip 1 One embodiment of the method of forming the insulating film 4D at a point where the ends of the signal inner lead 3A ₁ and the common inner lead 3A ₂ are adhered on the main surface thereof will be described with reference to FIGS. Manufacturing flow chart and cross-sectional view of each process) are demonstrated.

First, the α-ray shielding polyimide film 8 is applied to the entire area of the silicon wafer 10 shown in FIG. 25 (main surface plan view of the silicon wafer), semi-cured, and then photoetched to bond pads (external terminals). ) BP is exposed (step 101 in Fig. 24A). Next, the solvent peeling type dry film A is stuck (step 102). A predetermined pattern is exposed to this solvent peeling type dry film A (step 103), and it develops and a hole B is drilled (step 104).

Next, a paste-shaped insulator (print paste) C is applied to bury squeegee (embedded by squeegee) and harden (steps 105, 106 and 107). Next, the solvent release type dry film A is peeled off to form an insulating film 4D. Thereafter, the semiconductor chip having the insulating film 4D is completed by dicing along the solid line 10A on the silicon wafer 10 shown in FIG.

Another embodiment of the method for forming the α-ray shielding polyimide film 8 and the insulating film 4D is shown in Fig. 24B (manufacture flow diagram and cross-sectional view of the chip in each process). The α-ray shielding polyimide film 8 is applied over the entire area of 10 to photoetch to expose the bonding pads (external terminals) BP (step 201 in FIG. 24B).

Next, the dry film D for soldering resist is stuck (step 202). A predetermined pattern is exposed to this dry solder film D for soldering (step 203), and developed to form an insulating film 4D (step 204). Thereafter, the semiconductor chip having the insulating film 4D is completed by dicing along the solid line 10A on the silicon wafer 10 shown in FIG.

In addition, even if the insulating film 4D having a thick film thickness is formed by the silicon wafer process, the silicon wafer 10 is not bent because it is partially formed.

26 to 28 show an insulating film 4D at a position where at least the tip of the signal inner lead 3A ₁ and the common inner lead 3A ₂ and the chip support lead are bonded to the main surface of the semiconductor chip 1. ) Shows various pattern shapes.

As can be seen from the above description, according to the third embodiment, the α-ray shielding polyimide film 8 is coated over the entire main surface region other than the bonding pads (external terminals) BP of the semiconductor chip 1, and the semiconductor chip Since the insulating film 4D is formed at the place where the ends of the signal inner lead 3A ₁ and the common inner lead 3A ₂ are bonded to the main surface of (1), the polyimide film 8 for α-ray shielding 8 ? Can be shielded over the entire circuit formation area, and the semiconductor chip 1 can be adhesively fixed by the insulating film 4D.

In addition, since the insulating film 4D is formed on the main surface of the semiconductor chip 1 at least at the leading end of the internal lead 3A and the support lead 3C, the semiconductor chip 1 and the internal lead ( The floating capacity between 3A) can be reduced.

In addition, since the insulating film 4D is a thermosetting resin containing a printable inorganic filler, the insulating film 4D with high precision can be formed in the wafer process.

In addition, by forming the polyimide film 9 on the side opposite to the main surface of the semiconductor chip 1, adhesion between the semiconductor chip 1 and the resin (resin) becomes good, and thus package cracking can be prevented. .

After the insulating film 4D adheres at least the solvent-peelable dry film A to the silicon wafer 10, and has undergone the usual exposure and development processes, a paste-like insulator (print paste) is applied by squeegee. Since the insulating film 4D is formed by the batch process at high precision by the wafer process which embeds, heats and hardens | cures, and peels a solvent peeling type dry film, productivity can be improved.

In addition, since the insulating film 4D is formed only by exposure and development of the dry film D for soldering resist, the productivity can be further improved.

Example 4

In the resin-encapsulated semiconductor device according to the fourth embodiment of the present invention, as shown in FIG. 29 (part sectional perspective view), a plurality of signal inner leads 3A _{1 are} formed on the main surface of the semiconductor chip 1 of the first embodiment. And a common internal lead 3A ₂ is bonded by an adhesive via an insulating film 4 electrically insulated from the semiconductor chip 1, and these internal signal leads 3A ₁ and common internal leads 3A are provided. ₂ ) and the semiconductor chip 1 are electrically connected by the bonding wires 5, and the semiconductor device encapsulated with the molding resin 2A, Fig. 30 (Resin molding cut into the V-V line of Fig. 29) As shown in the sectional view showing the previous state, a part of the main surface of the semiconductor chip 1 is covered with a material 20 that is more flexible or fluid than the molding resin, and the material 20 is bonded wire ( 5) the whole is covered, and the outside of the substance 20 is sealed with resin 2A. .

That is, the dam 21 is provided so that the entirety of the bonding wire 5 passing through the common inner lead 3A ₂ may be covered with the flexible material 20, and the dam 21 may be, for example, in a flow state. The flexible, flowable material 20 made of silicone gel is dropped on the bonding wire 5 and cured, and then resin-sealed by transfer molding.

The dam 21 uses, for example, silicone rubber containing a silica filler having a high viscosity.

In addition, the flexible and flowable material 20 does not necessarily have to be a gel material as described above, and if the bonding wire 5 has flexibility or fluidity to the extent that the bonding wires 5 can be deformed, silicone grease or silicone Various materials such as rubber may be used.

By doing this, even when the main surface of the semiconductor chip 1 peels off and vapor expands during reflow soldering of the moisture absorbent package, the bonding wire 5 can follow the deformation freely. Disconnection can be prevented.

In addition, since the deformation of the bonding wire 5 is restrained during the transfer molding of the molding resin 2A, the bonding wire 5 at the time of molding even if the wire 5 is elongated so as to ride over the common inner lead 3A ₂ . ), Or the short circuit between the bonding wires 5 or the contact between the bonding wires 5 and the common inner lead 3A ₂ can be prevented.

Moreover, as long as it is only for preventing the deformation of the bonding wire 5, the material which coats the bonding wire 5 does not need to be a material which has flexibility and fluidity.

If there is a resin that can be bonded to a portion of the bonding wire 5 on the main surface of the semiconductor chip 1, an epoxy resin or the like having an elastic modulus similar to that of the transferred molded resin 2A on the outer side may be used.

In addition, when the flexible and flowable material 20 has fluidity, the degree needs to be higher than the melt viscosity at the time of transfer molding of the resin 2A.

In addition, since the resin 2A is not directly in contact with the bonding wire 5 by the flexible and flowable material 20, bonding is caused by relative thermal deformation between the semiconductor chip 1 and the molding resin 2A during the temperature cycle. The wire 5 is subjected to repeated deformation and does not fatigue and disconnect.

In the case of using the flexible and flowable material 20, no gap is generated on the surface of the bonding pad BP due to thermal stress, so that the aluminum of the bonding pad portion is not corroded by moisture.

FIG. 31 is a cross-sectional view showing a state before resin molding of the resin-encapsulated semiconductor device of another embodiment in the case of using the flexible, flowable material 20. FIG.

As shown in FIG. 31, the interface between the signal inner lead 3A ₁ and the resin 2A is less likely to have a gap than the main surface of the semiconductor chip 1, so that the signal inner lead of the bonding wire 5 ( 3A ₁₎ side of the bonding portion do not substantially cause a disconnection. Therefore, in this embodiment, the flexible and flowable material 20 is provided only in the vicinity of the bonding portion (first bonding) on the semiconductor chip 1 side where breakage is likely to occur. Thereby, if the bonding wire 5 can deform | transform freely, the some disconnection prevention effect is acquired.

In this embodiment, the common inner lead 3A ₂ is used instead of the dam 21 of FIG.

In this embodiment, however, the entirety of the bonding wire 5 is not covered with the flexible and flowable material 20. Therefore, when the temperature cycle acts on the package, the gap between the semiconductor chip 1 and the molding resin 2A is applied. Since the bonding wires 5 are repeatedly deformed due to relative thermal deformation, disconnection due to fatigue is more likely to occur than in the embodiment of FIG.

In addition, the deformation prevention of the bonding wire 5 during the transfer molding of the resin 2A also has some prevention effect.

In addition, since the amount of the flexible material and the flowable material 20 can be reduced and the height can be made low, it is effective in preventing disconnection at the time of reflow soldering and wire deformation at the time of transfer molding. It is possible to improve the mounting density.

32 is a cross-sectional view showing a state before resin molding of the resin-encapsulated semiconductor device of another embodiment in the case of using the flexible, flowable material 20. FIG.

In this embodiment, as shown in FIG. 32, the entirety of the main surface of the semiconductor chip 1 is covered with the flexible and fluidic material 20 so that the entire bonding wire 5 is covered.

The same effects as those of the embodiment of FIG. 30 can be obtained, and since the entire main surface of the semiconductor chip 1 is covered with the flexible and flowable material 20, moisture resistance can be further improved.

However, since the surface area of the flexible and flowable material 20 becomes large, a gap is generated at the interface with the molding resin 2A during reflow soldering, and if the vapor pressure is applied, cracks are easily generated in the upper molding resin 2A. do.

33 is a cross-sectional view showing a state before resin molding of the resin-encapsulated semiconductor device of another embodiment in the case of using the flexible, flowable material 20. FIG.

As shown in FIG. 33, the entirety of the bonding wire 5 provided on the main surface of the semiconductor chip 1 is covered with a material 20 that is more flexible or fluid than the molding resin 2A. It is.

The flexible and fluidic material 20 which covers the bonding wire 5 does not need to be convex on the main surface of the semiconductor chip 1, and may be attached only to the surface of the bonding wire 5.

In order to perform such coating, first, the flexible, fluidized material 20 having a low viscosity by dilution with a solvent is vertically dropped on the semiconductor chip 1, attached to the main sugar wire 5, and then formed by evaporating the solvent. do.

In this case, the greater the flexibility of the surface of the bonding wire 5 and the thicker the layer of the flowable material 20, the greater the prevention of disconnection and the deformation prevention effect of the bonding wire 5.

By configuring in this way, since the amount of the flexible and fluid material 20 for obtaining the same effect as the embodiment shown in FIG. 30 can be reduced, the flexible, fluid material 20 and the molding resin ( The cracking of the package can be prevented by the vapor pressure generated between 2A).

34 is a cross-sectional view showing a state after resin molding of the resin-encapsulated semiconductor device of another embodiment in the case of using the flexible, flowable material 20. FIG.

In this embodiment, as shown in FIG. 34, the bonding wire 5 is covered with the flexible and flowable material 20 and formed on the molding resin 2A opposite to the main surface of the semiconductor chip 1. The hole 22 is drilled to expose a portion of the semiconductor chip 1 substantially.

In this case, the term "substantial" is inevitably broken in the case where vapor pressure is generated inside the thin film of the molding resin 2A or the package 2 on the surface opposite to the main surface of the semiconductor chip 1 in the manufacturing process. It is assumed that a thin resin layer exists.

Thus, the moisture resistance of the bonding pad BP part can be ensured without causing the disconnection of the bonding wire 5 at the time of temperature cycling at the time of reflow soldering by the flexible and fluidic material 20, so that the molding resin 2A Even if the hole 22 is drilled in a part, the moisture resistance does not decrease.

In addition, since the vapor generated inside the package at the time of reflow solder is dissipated to the outside from the hole 22, the pressure does not rise and resin cracking does not occur.

The molding resin 2A may be present as long as it can be easily penetrated by vapor pressure even when the surface of the hole 22 opposite to the main surface of the semiconductor chip 1 is not completely exposed.

As can be seen from the above description, according to the fourth embodiment, even if the main surface of the semiconductor chip 1 peels off during reflow soldering and vapor expands, disconnection of the bonding wire 5 can be prevented.

In addition, it is possible to prevent short circuit between the wires due to deformation of the bonding wire 5 or contact between the bonding wire 5 and the common inner lead 3A ₂ during transfer molding.

In addition, it is possible to prevent cracking of the resin during reflow soldering without causing poor moisture resistance of the bonding pad BP portion and disconnection of the bonding wire 5 during the temperature cycle.

Example 5

In the resin-encapsulated semiconductor device of Example 5 of the present invention, as shown in FIG. 35 (cross-sectional view), the resin-encapsulated semiconductor device of Example 1 is concave on the opposite surface to the main surface of the semiconductor chip 1. The part or convex part 101, for example, a circular recessed part is provided.

The concave portion 101 constrains the molding resin 2A to the semiconductor chip 1 and generates stress in the molding resin portion of the corner portion on the side opposite to the main surface of the semiconductor chip 1 where reflow cracking occurs. It is possible to prevent the reflow crack by reducing the

Moreover, the process of the recessed part 101 may be etched, and you may use another method.

36A (the plan view seen from the opposite side to the main surface of FIG. 3) and 36B (the cross section cut by the horizontal center line of FIG. 36A) are the recessed parts 101 provided in the surface opposite to the main surface of the said semiconductor chip 1, FIG. As a diagram showing a modified example of the present invention, the annular recess 101a is provided on the surface opposite to the main surface of the semiconductor chip 1.

37A (plan view) and 37B (sectional view) show another modified example of the concave portion 101 provided on the surface opposite to the main surface of the semiconductor chip 1, and this example shows the semiconductor chip ( The rectangular recessed part 101b is provided in the surface opposite to the main surface of 1).

38A (plan view) and 38B (side view) show a modified example of the neck portion 101 provided on the surface opposite to the main surface of the semiconductor chip 1, and this example shows the semiconductor chip 1 Circular ball neck 101c is provided on the surface opposite to the main surface of the back side).

39A (plan view) and 39B (side view) show another modified example of the neck portion 101 provided on the surface opposite to the main surface of the semiconductor chip 1, and this example shows the semiconductor chip ( A square ball neck 101d is provided on the surface opposite to the main surface of 1).

40A (top view) and 40B (side view) show another modified example of the concave portion 101 provided on the surface opposite to the main surface of the semiconductor chip 1, and this example shows the semiconductor chip ( The elliptical recessed part 101e is provided in the surface opposite to the main surface of 1).

41A (plan view) and 41B (side view) show modifications of the concave portion or the convex portion 101 provided on the surface opposite to the main surface of the semiconductor chip 1, and this example shows the semiconductor. The concave portion and the convex portion 101f are provided by forming a plurality of grooves on the surface opposite to the main surface of the chip 1. This may be provided with a groove in a lattice shape.

As described above, the semiconductor chip 1 is formed into a molding resin by providing, for example, one of the concave portions or the convex portions 101a to 101f on the surface opposite to the main surface of the semiconductor chip 1. 2A) can be more firmly restrained.

Moreover, the stress which generate | occur | produces in 2 A of molding resin by the corner part of the surface opposite to the main surface of the semiconductor chip 1 can be reduced.

42 is a diagram showing another embodiment of the present invention according to the fifth embodiment, in which a silicon chip 102 is left on a surface opposite to the main surface of the semiconductor chip 1 of the fifth embodiment. For example, the concave portion or the convex portion 101 is provided on the surface opposite to the main surface of (1).

Thus, since the silicon oxide film 102 is left on the surface opposite to the main surface of the semiconductor chip 1, the adhesion between the silicon oxide film 102 and the molding resin 2A is strong, so that the semiconductor chip 1 Peeling of the molding resin 2A on the surface opposite to the main surface can be prevented.

In addition, the semiconductor chip 1 can be firmly constrained by the molding resin 2A by the concave portion or the convex portion 101.

Example 6

In the resin-encapsulated semiconductor device according to the sixth embodiment of the present invention, as shown in FIG. 43 (partial cross-sectional perspective view) and FIG. 44 (sectional view taken along line VI-VI of FIG. 43), the semiconductor of Example 1 On the main surface of the chip 1, a plurality of signal inner leads 3A ₁ and a common inner lead 3A ₂ are bonded with an adhesive via an insulating film 4 electrically insulated from the semiconductor chip 1, In the semiconductor device in which the signal inner lead 3A ₁ , the common inner lead 3A ₂ , and the semiconductor chip 1 are electrically connected by the bonding wires 5 and sealed with the molding resin 2A, the package ( A heat dissipation lead 301a electrically insulated from the semiconductor chip 1 is provided at a central portion of the side surface in the longitudinal direction of 2), and one end thereof extends to an upper portion of the heat generating portion of the main surface of the semiconductor chip 1. (Consisting of the first region and the second region formed integrally therewith), Wherein the other jjokkkeut a third region formed in the second region integral with the beads (301a) and the main surface of the semiconductor chip (1) of the package (2) is formed to extend to the opposite side of the plug lower face.

In this way, one end of the heat dissipation lead 301a electrically insulated from the semiconductor chip 1 at the central portion of the side surface in the longitudinal direction of the package extends to the upper portion of the heat generating portion of the main surface of the semiconductor chip 1. The other end of the heat dissipation lead 301a extends to the outer lower part of the surface opposite to the main surface of the semiconductor chip 1 of the package 2, thereby improving heat dissipation efficiency of heat of the heat generating portion of the semiconductor chip 1. Can be.

45 (partial cross-sectional perspective view) and 46 (sectional view cut along the Ⅶ-Ⅶ line | wire of FIG. 45) are the figures which showed the modification of the heat dissipation lead 301a shown in FIG. One end of the lead 301b extends to an upper portion of the heat generating portion of the main surface of the semiconductor chip 1, and the other end of the lead 301b of the heat dissipation lead 301b is formed of the main surface of the semiconductor chip 1 of the package 2. It extends to the top of the encapsulation.

And the extension part of the heat dissipation lead 301a becomes a heat sink.

One end of the heat dissipation lead 301b electrically insulated from the semiconductor chip 1 in the central portion of the side surface in the longitudinal direction of the package extends to the upper portion of the heat generating portion of the main surface of the semiconductor chip 1. Since the other end of the heat dissipation lead 301b extends to the outer upper portion of the main surface of the semiconductor chip 1 of the package 2, the heat dissipation efficiency of heat of the heat generating portion of the semiconductor chip 1 can be improved.

The other end portion of the heat dissipation lead 301b may be bent as shown in FIG. 46 by extending the portion of the package 2 extending to the outer upper portion of the main surface of the semiconductor chip 1 as shown in FIG.

The lead frames of the heat dissipation leads 301a and 301b are made of the same lead frame as the signal lead frames.

FIG. 47 (partial cross-sectional perspective view) and FIG. 48 (sectional view taken along the line VII-VII of FIG. 47) show a modification of the embodiment VI shown in FIG. 39, and the heat dissipation lead 301c. One end of the semiconductor chip 1 extends to the side opposite to the heat generating portion of the main surface, and the other end of the heat dissipation lead 301c is opposite to the main surface of the semiconductor chip 1 of the package 2. It extends to the outer bottom of the face. In this way, one end of the heat dissipation lead 301c electrically insulated from the semiconductor chip 1 at the central portion of the side surface in the longitudinal direction of the package extends to the side opposite to the heat generating portion of the main surface of the semiconductor chip 1. The other end of the heat dissipation lead 301c extends to the outer bottom of the surface on the opposite side to the main surface of the semiconductor chip 1 of the package 2, so that the heat dissipation efficiency of heat of the heat generating portion of the semiconductor chip 1 can be improved. Can be improved.

One end of the heat dissipation lead 301c is not necessarily electrically insulated from the semiconductor chip 1 by an insulating film.

In this case, the lead frame of the heat dissipation lead 301c is manufactured separately from the signal lead frame.

Example 7

The resin-encapsulated semiconductor device according to the seventh embodiment of the present invention is shown in FIG. 1 as shown in FIG. 49 (partial cross-sectional perspective view) and FIG. 50 (sectional view taken along the line VII-Ⅸ of FIG. 49). The insulating film 4 in which several internal signal leads 3A ₁ and common internal leads 3A ₂ are electrically insulated from the semiconductor chip 1 on the main surface of the rectangular semiconductor chip 1 of the first embodiment. A semiconductor device in which a resin-encapsulated semiconductor device is electrically connected to each other by an adhesive wire, and the signal inner lead 3A ₁ , the common inner lead 3A ₂ , and the semiconductor chip 1 are electrically connected by a bonding wire 5. In the main surface of the semiconductor chip 1, a bonding wire 5 wired on the main surface and a bonding pad BP not intersecting with the common internal lead 3A ₂ are disposed.

The device arrangement and bonding pads BP of the semiconductor chip 1 of the present embodiment 7 are as shown in FIG. 51 (arrangement plan view).

In other words, the memory cell array MA is disposed almost all over the surface of the DRAM 1. The DRAM 1 of the seventh embodiment is not limited to this, but the memory cell array is largely divided into eight memory cell arrays 11A to 11H. In FIG. 51, four memory cell arrays 11A to 11D are arranged above the DRAM 1, and four memory cell arrays 11E to 11H are arranged below. Each of these eight divided memory cell arrays 11A to 11H is further divided into sixteen memory cell arrays (MA) 11. That is, 128 memory cell arrays 11E are disposed in the DRAM 1. One memory cell array 11 subdivided into 128 pieces has a capacity of 128 (Kbit).

A sense amplifier circuit (SA) 13 is disposed between the two memory cell arrays 11 among the 128 subdivided into the DRAM 1. The sense amplifier circuit 13 is composed of a complementary MOSFET (CMOS). A column address decoder circuit (YDEC) 12 is disposed at one end of each of the memory cell arrays 11A, 11B, 11C, and 11D of the eight divided DRAMs 1. . Similarly, a column address decoder circuit (YDEC) 12 is disposed at one end of each of the upper side of the memory cell arrays 11E, 11F, 11G, and 11H.

Between the memory cell arrays 11A and 11B, the memory cell arrays 11C and 11D, the memory cell arrays 11E and 11F, and the memory cells among the eight divided ones of the DRAM 1; The peripheral circuit 17 and the external terminal BP are disposed between the arrays 11G and 11H, respectively. In addition, each area of the lower side of the memory cell arrays 11A, 11B, 11C, and 11D, and the upper side of each of the memory cell arrays 11E, 11F, 11G, and 11H, respectively. The peripheral circuit 17 and the peripheral circuit 18 are provided. As the peripheral circuit 17, each of the main amplifier circuit, the output buffer circuit, the substrate potential (V _BB ) generation circuit, and the power supply circuit is disposed.

As the peripheral circuit 18, a low address strobe (RAS) circuit, a write enable (WE) circuit, a data input buffer circuit, a Vcc limiter circuit, an X address driver circuit (logic stage), an X series redundant circuit, X Address buffer circuit, column address strobe (CAS) circuit, test circuit, VDL limiter circuit, Y address driver circuit (logic stage), Y system redundant circuit, Y address buffer circuit, Y address driver circuit (drive stage), X Each of an address driver circuit (drive stage) and a mat selection signal circuit (drive stage) is disposed (see FIG. 4 and its description).

The external terminal BP is disposed in a direction parallel to the long side of the semiconductor chip to form the resin-encapsulated semiconductor device 2 in a LOC structure, and the common inner lead 3A ₂ at the center of the long side of the semiconductor chip 1. Since the inner lead 3A is extended up to), the inner wire 3A is disposed along the bonding wire 5 and the outer terminal, which are arranged at the center of the DRAM 1 and are wired on the main surface of the semiconductor chip 1. The common internal leads 3A ₂ are arranged so as not to intersect.

The external terminal BP is disposed from the upper end side to the lower end side of the DRAM 1 in the regions defined by the memory cell arrays 11A to 11H, respectively. The signals applied to the external terminal BP are for the reference voltage GND, the power supply, and the signal, and the details thereof are described in the resin-encapsulated semiconductor device 2 shown in FIG. 1 above. Omit.

Basically, since the internal lead 3A to which the reference voltage Vss and the power supply voltage Vcc are applied extends from the upper side to the lower side on the surface of the DRMA 1, the DRAM 1 extends in the extending direction thereof. Therefore, several external terminals BP for the reference voltage Vss and the power supply voltage Vcc are arranged. In other words, the DRAM 1 is configured to sufficiently supply power for each of the reference voltage Vss and the power supply voltage Vcc.

As described above, according to the seventh embodiment, a bonding pad BP in which the bonding wire 5 and the common internal lead 3A ₂ which are wired on the main surface of the semiconductor chip 1 does not intersect is disposed. That is, since the external terminal is disposed between the inner lead 3A ₁ and the common inner lead 3A ₂ , the bonding wire 5 for connecting the plurality of signal inner leads 3A ₁ and the semiconductor chip 1 to each other. The short circuit of the internal common lead 3A ₂ can be prevented.

Next, the lead frame will be described in detail.

As shown in FIG. 52 (lead frame overall plan view), the lead frame 3 of the seventh embodiment is provided with twenty signal inner leads 3A ₁ and two common inner leads 3A ₂ . The inner leads (3A ₁₎ is the first 50 degrees (cross section) which, as shown in, the external lead on the film (insulator) 4 and the bonding portion (the first area) for isolation of His-signal inside lead (3A ₁₎ The gap between the portion (second region) on the side of the (3B) side and the semiconductor chip 1 is wider than the gap between the portion joined with the insulating film (insulator) 4 and the semiconductor chip 1. By using the inner lead 3A as a step structure as described above, the stray capacitance between the semiconductor chip 1 and the signal inner lead 3A ₁ is smaller than that of the conventional one, thereby improving signal transmission speed and reducing electric noise. We can plan.

In the seventh embodiment, the arrangement of the bonding pads BP on the main surface of the semiconductor chip 1 and other than the lead frame are the same as those of the first embodiment.

It goes without saying that the technique of the second to sixth embodiments can be applied to the seventh embodiment.

Example 8

The resin-encapsulated semiconductor device according to the eighth embodiment of the present invention is a modification of the lead frame of the first embodiment as shown in FIG. 53 (a plan view showing a schematic configuration of the lead frame of the eighth embodiment). In order to fix the surface opposite to the main surface of the semiconductor chip 1, the inner lead 3C ₁ (chip support lead) which is not energized is bent. That is, in the chip support lead including the first region and the second region, the first region is bonded to the main surface of the semiconductor chip, and the distance between the main surface of the chip and the second region is equal to the main surface of the chip. It is larger than the distance of the first area.

Then, as shown in Fig. 54A (semiconductor chip fixing section sectional view) and Fig. 56 (sectional view of the signal inner lead portion and the common inner lead portion in the state before resin molding), a plurality of signal inner leads 3A _{1 are shown.} ) And the common internal lead 3A ₂ are arranged in a state of being floating on the main surface of the semiconductor chip 1 so as to be coplanar with the second region of the chip support lead 3C ₁ (FIG. 56). The semiconductor chip 1 is adhesively fixed by the adhesive 7 in the chip support lead 3C ₁ .

The adhesive 7 may be any of the above-described adhesives such as epoxy resin and resol resin.

In addition, or it may be bonded by interposing the film (4) between the first insulating region and the semiconductor chip 1, the chip supporting leads ₍₁ 3C) for.

In this case, when each of the plurality of signal inner leads 3A ₁ and the common inner leads 3A ₂ and the bonding pad BP of the semiconductor chip 1 are connected with the bonding wire 5, the signal inner leads 3A ₁ and The common internal lead 3A ₂ is pressed onto the semiconductor chip 1 with a jig from above, and wire bonding is performed.

When the wire bonding ends and the pressing jig is removed, the signal inner lead 3A ₁ and the common inner lead 3A _{2 are} shown in FIG. 56 by the springback effect of the chip supporting inner lead 3C ₁ . It is in a state.

As shown in Fig. 54B, for example, an insulating film having a predetermined thickness between the support lead 3C of the lead frame 3 and the main surface of the semiconductor chip 1 applied to the first embodiment described above. By attaching and fixing with an adhesive 7 via 4), the signal inner lead 3A ₁ and the common inner lead 3A ₂ may be arranged in a state of being floating on the main surface of the semiconductor chip 1. (Figure 56). In this case, although the thickness of the said insulating film 4 is generally about 150 micrometers, it is also possible to set it as more thickness.

As shown in FIG. 55 (sectional view showing the state before the resin molding), for example, the signal inner lead 3A ₁ , the common inner lead 3A ₂ , and the main surfaces of the semiconductor chip 1 and the like. An insulating plate 40 is inserted in between, and the signal inner lead 3A ₁ , the common inner lead 3A ₂ , and the semiconductor chip 1 are electrically connected by the bonding wire 5, and sealed with a molding resin. It may be done.

In addition, as shown in FIG. 57 (cross-sectional view showing a state before resin molding), one side of the left and right sides of the signal inner lead 3A ₁ and the common inner lead 3A _{2 is} formed. for example, signals inside the lead on the left side (3A ₁₎ and the common inner leads (3A ₂₎ and is inserted only between the main surface of the semiconductor chip (1), the signal inside the lead in the right side (3A ₁₎ and the common inner leads (3A ₂ ) the signal inner lead 3A ₁ , the common inner lead 3A ₂ , and the semiconductor chip 1 are electrically connected by the bonding wires 5 while floating on the main surface of the semiconductor chip 1. It may be sealed with a molding resin.

Also, for example, in order to arrange the plurality of signal inner leads 3A ₁ and the common inner leads 3A ₂ in a floating state on the main surface of the semiconductor chip 1 (FIG. 56), FIG. As illustrated, the chip support leads 3C ₁ are deeply bent to form chip support leads 3C ₂ , and the chip support leads 3C ₂ are opposite to the main surface of the semiconductor chip 1. The surface may be adhesively fixed. By doing this, the semiconductor chip is formed by the chip support lead 3C ₂ such that the signal inner lead 3A ₁ and the common inner lead 3A ₂ are arranged in a floating state on the main surface of the semiconductor chip 1. Since the opposite side to the main surface of (1) is adhesively fixed, the process of adhering the insulating film 4 is unnecessary. In addition, the semiconductor chip 1 is firmly fixed. In addition, since the lead wire is not bonded onto the memory cell, damage to the memory cell can be reduced.

As described above, according to the eighth embodiment, moisture absorption can be reduced by not using or minimizing the insulating film 4, so that the solder reflow resistance can be made advantageous.

Further, in the eighth embodiment, it is preferable that the α-ray shielding polyimide film is applied to the entire main surface region other than the bonding pad of the semiconductor chip 1.

Example 9

In the resin-encapsulated semiconductor device according to the ninth embodiment of the present invention, as shown in FIGS. 58 and 59 (arrangement diagram on the semiconductor chip), the bonding pads BP (solder bump 5C) connected to the inner lead are mirror-symmetric. The two semiconductor chips 1A and 1B formed in this manner are prepared.

In Fig. 58, the CAS0 terminal (bonding pad BP) and the CAS1 terminal (bonding pad BP) are separated, and the other terminal (bonding pad BP) is common. In this arrangement, the capacity in the word direction is doubled.

In Fig. 59, the Do terminal and the Di terminal are separated, and the other terminals are common. By such arrangement, the capacity in the bit direction is doubled.

As shown in FIG. 60 (sectional view of the package), the inner lead 3A is disposed between the two main surfaces of the two semiconductor chips 1A and 1B with the inner lead 3A interposed therebetween. ) And the bonding pads BP of the semiconductor chip 1 are electrically connected by the solder bumps 5C and sealed with a molding resin.

In this way, in the two semiconductor chips 1A and 1B in which the bonding pads BP with the inner lead 3A are mirror-symmetrically, the inner lead 3A and the inner lead 3A are interposed between the respective main surfaces. Since the bonding pads BP of the semiconductor chip 1 are electrically connected with the solder bumps 5C and sealed with a molding resin, a device having a double capacity can be mounted without changing the external shape of the package 2.

Example 10

The resin-encapsulated semiconductor device of Example 10 of the present invention is shown in FIG. 61 (a perspective view seen from the side facing the wiring board of the resin-enclosed semiconductor device of Example 10) and in FIG. As shown in the cross-sectional view (cutting section), a heat dissipation groove 50 that is open toward the outside is provided on a surface of the semiconductor device package 2 of the first embodiment that faces the substrate. In this case, the distance between the bottom surface 50A of the heat dissipation groove 50 and the semiconductor chip 1, that is, the thickness dimension of the molding resin 2A at the bottom of the semiconductor chip 1 is set to 0.3 mm or less.

Thus, by providing the heat dissipation groove 50, as shown in Figs. 68 and 69 (sectional view showing the state where the resin-encapsulated semiconductor device of Example 10 is mounted on the wiring board), the substrate 51A is shown. Or 51B and the gap 51D between the bottom surface 50A of the heat dissipation groove 50 becomes large, and when air is blown in the vertical direction of the ground to carry out cooling, air also flows in the gap 51D. Heat dissipation is also performed at 50A to reduce the thermal resistance of the semiconductor device.

In addition, in the structure of the present embodiment, the molding resin 2A under the semiconductor chip 1 becomes thin and research is required during resin molding. However, when the molding resin 2A having a low melt viscosity during molding is used, As shown in the figure, the package 2 can be formed.

Next, a modification of the resin-encapsulated semiconductor device of Example 10 is shown in FIG. 63 (sectional view).

In the semiconductor device of this modification, as shown in FIG. 63, the heat dissipation grooves 53 are also provided on the upper surface of the package 2 shown in FIG. Each distance between the bottom surface 50A of the heat dissipation groove 50 and the bottom surface 53A of the heat dissipation groove 53 and the semiconductor chip 1, that is, each of the molding resins at the bottom and the top of the semiconductor chip 1, respectively. Thickness dimension is less than 0.3mm.

By thinning the molding resin 2A on the upper portion of the semiconductor chip 1 of the package 2 in this manner, the heat transfer surface increases and the thermal resistance of the semiconductor device is reduced, so that the overall thermal resistance can be reduced by that much. Also, as shown in FIG. 69, the spacing when the semiconductor devices are arranged on the substrates 51A and 51B can be shortened by twice the depth dimension of the grooves, thereby increasing the mounting density.

Another modification of the semiconductor device of the tenth embodiment is shown in FIG. 64 or FIG.

In the semiconductor device of this modification, as shown in FIG. 64 or FIG. 65, the lower molding resin 2A of the semiconductor chip 1 of the package 2 shown in FIG. 62 or FIG. 63 is removed. The surface opposite to the main surface of the semiconductor chip 1 is exposed.

Thus, by removing the lower molding resin 2A of the semiconductor chip 1 of the package 2 and exposing the side opposite to the main surface of the semiconductor chip 1, the thermal resistance of the semiconductor device can be further reduced. The whole heat resistance can be reduced by that much.

Thereby, generation | occurrence | production of the crack by the temperature cycle from the corner part of the semiconductor chip 1 can be prevented.

Another modification of the semiconductor device of the tenth embodiment is shown in FIG. 66 or FIG.

In the semiconductor device of this modification, as shown in FIG. 66 or FIG. 67, the lower molding resin 2A of the semiconductor chip 1 of the package 2 shown in FIGS. 62 and 64 is removed. In exposing the surface opposite to the main surface of the semiconductor chip 1, the relationship between the semiconductor chip 1 and the external lead 3B is reversed.

By doing in this way, cooling efficiency can be improved when the cooling of an upper surface is dominant with respect to the mounting board 51. FIG.

In addition, in the modification shown in FIG. 66 or FIG. 67, the heat dissipation groove may be provided in the board | substrate 51 side of the package 2, too.

Next, a description will be given of an embodiment of a substrate mounting method of the resin encapsulated semiconductor device shown in Figs. 61 to 67 of the present invention.

One embodiment of the substrate mounting method of the resin-encapsulated semiconductor device shown in Figs. 61 to 67 is shown in Fig. 68, for example, as shown in Fig. 61 (Fig. 61). 60A) -60H are surface-mounted by the solder 61 on both surfaces of the board | substrate 51A and 51B, respectively.

By mounting the resin-encapsulated semiconductor devices 60A to 60H on the substrates 51A and 51B in this manner, the mounting density of the semiconductor device can be improved and the substrate 51A of the package 2 can be improved. And heat dissipation is possible at the 51B side. That is, the heat dissipation of the resin-encapsulated semiconductor devices 60A to 60H is performed by the gaps 51D between the respective packages 2 and the substrates 51A or 51B on which they are mounted, thereby reducing the resistance of the blowing air. Thus, heat dissipation efficiency can be improved.

As shown in FIG. 69, for example, the heat dissipation groove 53 and the convex portion 54 of the upper portion of the package 2 of the resin-encapsulated semiconductor device of the embodiment shown in FIG. It is mounted between the board | substrate 51A and 51B.

By mounting the resin-encapsulated semiconductor device in this manner, the mounting density of the semiconductor device can be further improved. The heat dissipation is also possible on the substrate 51A or the substrate 51B side of the package 2. That is, since the distance at which the resin-encapsulated semiconductor device is placed on the substrate 51A or 51B can be shortened by twice the depth dimension of the groove, the mounting density can be increased (Example 1 of FIG. 64). 5 times).

In addition, since heat dissipation of the resin-encapsulated semiconductor device is performed by the gap 51D between the package 2 and the substrate 51A or the substrate 51B on which the resin is mounted, the heat resistance can be improved by reducing the resistance of the blowing air. have.

Example 11

The resin encapsulated semiconductor device for encapsulating the DRAM according to the eleventh embodiment of the present invention is shown in Figs.

70 and 71, the DRAM (semiconductor chip 1) is sealed with a resin encapsulated package 2 of ZIP (Zigzag In-Line Package) type. The DRAM 1 has a large capacity of 16 [Mbit] x 1 [bit] and has a size of 16.48 [mm] x 8. It consists of a flat rectangular shape of 54 [mm]. The DRAM 1 is sealed in a 450 mil resin encapsulated package 2.

As shown in FIG. 71, a memory cell array and a peripheral circuit are mainly disposed on the main surface of the DRAM 1. The memory cell array will be described in detail later, but a plurality of memory cells (memory elements) storing 1 [bit] of information are arranged in a matrix form. The peripheral circuit is arranged as a direct peripheral circuit and an indirect peripheral circuit. The direct peripheral circuit is a circuit for directly controlling the information write operation or the information read operation of the memory cell. The direct peripheral circuit includes a low address decoder circuit, a column address decoder circuit, a sense amplifier circuit, and the like. The indirect peripheral circuit is a circuit for indirectly controlling the operation of the direct peripheral circuit. The indirect peripheral circuit includes a clock signal generation circuit, a buffer circuit, and the like.

An inner lead 3A is disposed on the main surface of the DRAM 1, that is, on the main surface on which the memory cell array and the peripheral circuit are arranged. An insulating film 4 is interposed between the DRAM 1 and the internal lead 3A. The insulating film 4 is formed of a polyimide resin film, for example. An adhesive layer (not shown) is provided on each surface of the insulating film 4 on the DRAM 1 side and the inner lead 3A side. As the adhesive layer, for example, polyether amide imide resin or epoxy resin is used.

This type of package 2 uses a lead on chip (LOC) structure in which an internal lead 3A is disposed on the DRAM 1.

Since the package 2 employing the LOC structure can freely extend the inner lead 3A without being restricted by the shape of the DRAM 1, it is possible to encapsulate the DRAM 1 having a large size corresponding to this increase. . That is, the package 2 employing the LOC structure can reduce the package size (package size) even if the size of the DRAM 1 increases with the increase in capacity, thereby increasing the mounting density.

The inner lead 3A integrally forms one end thereof with the outer lead 3B. The external leads 3B are numbered with the signals applied to them according to the standard specifications. Terminals 1, 3, 5, ... from the left end of the top of FIGS. 70 and 71; , Terminal 21, Terminal 23, Radix terminal is prepared sequentially, Terminal 2, Terminal 4, Terminal 6,… from the bottom left. , Terminal 22 and Terminal 24 have excellent terminals. That is, this package 2 consists of a total of 24 terminals of 12 terminals at the top and 12 terminals at the bottom.

The first terminal is an address signal terminal (A ₉ ), the second terminal is an empty terminal, the third terminal is a column address strobe signal terminal ( ), Terminal 4 is an empty terminal, terminal 5 is a data output signal terminal, terminal 6 is a reference voltage Vss terminal. The reference voltage Vss is, for example, the operating voltage of the circuit 0 [V]. Terminal 7 is the power supply voltage Vcc terminal. The power supply voltage Vcc is, for example, an operating voltage of the circuit 5 [V].

Terminal 8 is the data input signal terminal (Din), terminal 9 is the empty terminal, terminal 10 is the write enable signal terminal ( ), Terminal 11 is the low address strobe signal terminal ( 12 is an address signal terminal A ₁₁ and 13 is an address signal terminal A ₁₀ . Terminal 14 is an address signal terminal (A ₀ ), Terminal 15 is an address signal terminal (A ₁ ), terminal 16 is an address signal terminal (A ₂ ), terminal 17 is an address signal terminal (A ₃ ), and terminal 18 The terminal is a power supply voltage Vcc terminal. The power supply voltage Vcc is, for example, an operating voltage of the circuit 5 [V].

Terminal 19 is a reference voltage Vss terminal, and this reference voltage Vss is, for example, the operating voltage of the circuit 0 [V].

Terminal 20 is an address signal terminal (A ₄ ), Terminal 21 is an address signal terminal (A ₅ ), terminal 22 is an address signal terminal (A ₆ ), terminal 23 is an address signal terminal (A ₇ ), and terminal 24 is The terminal is an address signal terminal A ₈ .

The other end side of the inner lead 3A crosses each of the long sides of the rectangular shape of the DRAM 1 and extends to the center side of the DRAM 1. The tip of the other end side of the inner lead 3A is connected to an external terminal (bonding pad) BP arranged in the center portion of the DRAM 1 via the bonding wire 5. The bonding wire 5 uses aluminum (Al) wire. As the bonding wire 5, a gold (Au) wire, a copper (Cu) wire, a coated wire coated with an insulating resin on the surface of the metal wire, or the like may be used. The bonding wire 5 is bonded by the bonding method which combined ultrasonic vibration with thermocompression bonding.

Each of the inner leads Vcc 3A of the seventh terminal and the eighteenth terminal of the inner lead 3A is integrally formed, and the central portion of the DRAM 1 extends in parallel with its long side (this inner portion). The lead (Vcc) 3A is called a common internal lead or busbar internal lead). Similarly, each of the internal leads Vss 3A of terminals 6 and 19 is integrally formed, and the central portion of the DRAM 1 extends in parallel with its long side (this internal lead Vss ( 3A) is called common internal lead or busbar internal lead). Each of the inner lead Vcc 3A and the inner lead Vss 3A extends in parallel in the region defined by the distal end of the other inner lead 3A. Each of the internal leads Vcc 3A and the internal leads Vss 3A is configured to supply the power supply voltage Vcc and the reference voltage Vss at any position on the main surface of the DRAM 1. That is, the package 2 is configured to easily absorb power noise, and is configured to speed up the operation speed of the DRAM 1.

On the rectangular short side of the DRAM 1, a chip support lead 3C is provided.

Each of the inner lead 3A, outer lead 3B, and chip support lead 3C is cut and molded in a lead frame. The lead frame is made of, for example, Fe-Ni (for example, Ni content 42 or 50 [%]) alloy, Cu, or the like.

The DRAM 1, the bonding wire 5, the inner lead 3A, and the chip support lead 3C are encapsulated with a resin encapsulating portion 6. The resin encapsulation portion 6 uses an epoxy resin to which a phenol-based curing agent, silicone rubber and filler are added in order to reduce stress. Silicone rubber has the effect of reducing the thermal expansion together with the elastic modulus of the epoxy resin. The filler is formed of spherical silicon oxide particles, and similarly has a function of lowering the coefficient of thermal expansion.

As can be seen from the above description, according to the eleventh embodiment, the package density of the ZIP package 16MDRAM 1 is mounted on the substrate in the vertical mounting method.

Example 12

FIG. 72 is a cross-sectional view taken along the line XII-XII of FIG. 74 showing a semiconductor device according to another embodiment of the present invention, FIG. 73 is a partial cutaway cross-sectional view cut along the line XIII-XIII of FIG. 74, and FIG. Fig. 75 is a schematic plan view of a semiconductor chip showing a circuit block of this semiconductor device.

The twelfth embodiment is a resin encapsulated semiconductor device, and its package structure is a dual in-line package (DIP) using a no-tap lead frame method.

The package body 401 is made of a resin in which, for example, a filler such as silica (SiO ₂ ) is filled in an epoxy resin and its thermal expansion coefficient is close to the thermal expansion coefficient of silicon, and has a structure that is strong against bending strength and reflow cracking. have.

On both sides of the package body 401 in the longitudinal direction, several leads 402 constituting the input / output pins and the power pins are bent downward while extending outward. In other words, a portion of the inner lead is bonded through the semiconductor chip and the insulator, and the distance between the second region of the inner lead portion and the back surface of the semiconductor chip is less than the distance between the first region of the inner lead portion and the back surface of the semiconductor chip. These leads 402 formed to be large are made of, for example, Cu, and the surface thereof is plated with, for example, a Sn-Ni alloy.

On the upper surface of the lead 402 embedded in the package body 401, a rectangular insulating film 403a made of, for example, a polyimide resin is joined via an adhesive 404. This adhesive agent 404 is a polyimide resin adhesive, for example.

As shown in FIG. 74, the lead 402 is bent at approximately right angles to the horizontal direction on the lower surface of the insulating film 403a. For example, the tip portion of the lead 402 to which the Ag plating is applied is formed of the insulating film 403a. Protrude outward from short side;

As shown in Figs. 72 and 73, the lead 402 is bent downward from the lower surface of the insulating film 403a, so that the lead 402 and the insulating film (generated by this) are formed. In order to prevent deformation of the lead 402 at the time of shaping | molding, the 2nd insulating film 403b of the film thickness substantially the same as this gap is adhere | attached to the clearance gap with 403a. The insulating film 403b is made of, for example, the same polyimide resin as the insulating film 403a.

On the upper surface of the insulating film 403a, a rectangular semiconductor chip 405 made of silicon single crystal is bonded via an adhesive 406. The adhesive 406 is, for example, a silicone resin adhesive. The area of the chip 405 is slightly smaller than that of the insulating film 403a. In addition, the upper surface side of the chip 405 is an integrated circuit forming surface, and a protective film 407 made of, for example, polyimide resin is deposited on the surface thereof for planarization or the like.

On the integrated circuit formation surface of this chip 405, for example, a 4 Mbit MOS DRAM is formed.

As shown in FIG. 75, the memory cell array M of this 4 Mbit MOS DRAM is disposed in the center portion of the chip 405, and the peripheral circuit P is disposed on both sides thereof. A plurality of bonding pads 408 are disposed between the short side circumferential edge of the chip 405 and the peripheral circuit P in a direction substantially parallel to the short sides, and each bonding pad 408 and the lead 402 are formed of Au, It is electrically connected via the wire 409 which consists of Cu or Al.

By the way, in the resin-sealed semiconductor device, parasitic capacitance is usually formed between the chip 405 and the lead 402. Since the parasitic capacitance is inversely proportional to the distance between the chip 405 and the lead 402 and increases in proportion to their opposing area, most of the lead 402 embedded in the package body 401 is disposed on the bottom surface of the chip 405. In the package structure located at, since the opposing area between the chip 405 and the lead 402 becomes large, a large parasitic capacitance is formed.

However, in the twelfth embodiment, since the middle portion of the lead 402 located on the lower surface of the chip 405 is bent downward, the distance between the chip 405 and the lead 402 is increased by that amount. Therefore, compared to the prior art in which the middle portion of the lead 402 is not bent downward, the parasitic capacitance formed between the chip 405 and the lead 402 can be reduced.

As a result, the capacity of the lead 402 constituting the input / output pin is also reduced, and the access to the 4 Mbit MOS DRAM formed in the chip 405 is increased.

In the twelfth embodiment, the second insulating film 403b made of the same material as the insulating film 403a was adhered to the gap between the lead 402 and the insulating film 403a. For example, the insulating films 403a and 403b are integrally formed. The insulating film 403a and the insulating film 403b may be formed of different materials.

Example 13

FIG. 76 is a cross sectional view taken along line XIII-XIII of FIG. 77 showing another semiconductor device of another embodiment of the present invention, FIG. 77 is a schematic plan view of the semiconductor device, and FIG. 78 is a schematic view of the semiconductor chip showing a circuit block of the present semiconductor device. It is a plan view.

The package structure of the thirteenth embodiment is a DIP of a no-tap lead frame type as in the twelveth embodiment, but the twelveth embodiment is a so-called chip on lead in which the lead 402 is disposed on the lower surface of the chip 405. In the present embodiment, the thirteenth embodiment uses a so-called lead on chip method in which the chip 405 on the lower surface of the lead 402 is arranged.

That is, the chip 405 encapsulated in the package body 401 made of the same resin as in the twelfth embodiment has an upper surface side thereof as an integrated circuit forming surface. For example, a 4 Mbit MOS DRAM is formed on the integrated circuit forming surface. Formed.

As shown in FIG. 78, the peripheral circuit P extending in the long side direction of the chip is disposed in the center portion of the chip 405, and the memory cell array M is disposed on both sides thereof. By arranging the peripheral circuit P in the center of the chip 405, the peripheral circuit P extends in the long side direction of the chip 405 as compared with the 4Mbit MOS DRAM of the twelfth embodiment in which the peripheral circuit P is arranged on the short side of the chip 405. Since the wiring length can be shortened, the wiring delay is further reduced.

The bonding pads 408 are concentrated between the peripheral circuit P and the memory cell array M in the central portion of the chip 405.

As shown in FIG. 76, the rectangular insulating film 403a which consists of polyimide resin, for example is bonded to the upper surface of the chip 405 via the adhesive agent 406. As shown in FIG. The insulating film 403a has a slightly larger area than the chip 405, and an open hole 410 is formed in the center portion.

A plurality of leads 402 are bonded to the upper surface of the insulating film 403a via an adhesive 404. As shown in FIG. 77, the lead 402 is bent in the horizontal direction on the upper surface of the insulating film 403a, and the tip thereof is disposed near the bonding pad 408. As shown in FIG. The lead 402 and the bonding pad 408 are electrically connected to each other via the wire 409.

As shown in FIG. 76, the lead 402 is bent upwards on the upper surface of the insulating film 403a, and the gap between the lead 402 and the insulating film 403a thus formed is approximately equal to this gap. The insulating film 403b of the same film thickness is bonded.

As described above, in the thirteenth embodiment, since an intermediate portion of the lead 402 located on the upper surface of the chip 405 is bent upward, the distance between the chip 405 and the lead 402 is increased by that amount. The parasitic capacitance formed between the chip 405 and the lead 402 can be reduced as compared with the prior art in which the middle portion of the lead 402 is not bent upward.

Therefore, the capacity of the lead 402 constituting the input / output pins is also reduced, thereby speeding up access to the 4Mbit MOS DRAM formed in the chip 405.

As mentioned above, although the invention made by this inventor was demonstrated concretely according to the said Example, this invention is not limited to the said Example 12, 13, Of course, it can be variously changed in the range which does not deviate from the summary.

For example, as shown in FIG. 79, the predetermined integrated circuit formed on the chip 405 and the lead 402 may be applied to a package structure in which the lead 411 is electrically connected to each other. That is, as shown in FIG. 79, when most of the leads 402 embedded in the package body 401 are arranged along the lower surface of the chip 405, the solder bumps 411 are connected to each other. By bending the intermediate portion of the lead 402 downward, the parasitic capacitance formed between the lead 402 and the chip 405 can be reduced.

In addition, although the package of Example 12, 13 was DIP, it is not limited to this, For example, a small outline J-lead Package (SOJ), a plastic leaded chip carrier (PLC), etc. may be sufficient.

Moreover, it is not limited to the semiconductor device using a no-tap lead frame system, For example, it is applicable also to the semiconductor device of the system which arrange | positions the lead to the upper surface of the chip mounted in the tab.

In the above description, the case where the invention made by the present inventors is mainly applied to the MOS RAM, which is the background of the use, has been described. However, the present invention is not limited thereto. For example, other semiconductor memories such as EPROMs, microcomputers, etc. The same applies to logic LSIs.

As mentioned above, although this invention was demonstrated concretely according to the said Example, this invention is not limited to the said Example, Of course, it can be variously changed in the range which does not deviate from the summary.

Among the inventions disclosed in the present application, the effects obtained by the representative ones will be briefly described as follows.

[1] The reliability of the semiconductor device can be improved.

[2] In the semiconductor device, it is possible to improve the signal transmission speed and reduce the electric noise due to the stray capacitance between the semiconductor chip and the lead.

[3] The heat dissipation efficiency of the heat generated in the semiconductor device can be improved.

[4] In the semiconductor device, the influence of heat during reflow can be reduced.

[5] In the semiconductor device, the influence of heat in the temperature cycle can be reduced.

[6] Forming defects can be prevented in the semiconductor device.

[7] In the semiconductor device, productivity can be improved.

[8] The moisture resistance of the semiconductor device can be improved.

The parasitic capacitance formed between the chip and the lead can be reduced by bending a portion of the lead disposed on the upper or lower surface of the chip accommodated in the package outward with respect to the upper or lower surface of the chip.

[10] Since the distance between the chip and the lead can be sufficiently increased by interposing the insulating film between the chip and the lead, the parasitic capacitance formed between the chip and the lead can be reduced.

[0011] By arranging the peripheral circuit at the center of the chip, the wiring length extending in the long side direction of the chip can be shortened, so that the wiring delay can be reduced.

Claims (8)

A semiconductor chip having a main surface and a back surface opposite to the main surface, comprising: a semiconductor chip having an integrated circuit and a plurality of external terminals formed on the main surface, and a plurality of leads each having an inner lead and an outer lead integrally formed with the inner lead, A plurality of leads each of which some of the inner leads are located on a main surface of the semiconductor chip, a plurality of bonding wires electrically connecting the plurality of external terminals and the inner leads of the plurality of leads and at least a main surface of the semiconductor chip And a resin body for sealing the inner leads of the plurality of leads and the plurality of bonding wires, and a back surface of the semiconductor chip is exposed from the resin body. The semiconductor device of claim 1, wherein the inner lead has a first portion adhered to a main surface of the semiconductor chip and a second portion disposed on a main surface of the semiconductor chip and positioned in a region different from the first portion. A plurality of bonding wires are connected to the first portion of the inner lead. The semiconductor device according to claim 2, wherein a distance between the second portion and a main surface of the semiconductor chip in a thickness direction of the semiconductor chip is larger than a distance between the first portion and a main surface of the semiconductor chip. The semiconductor device according to claim 3, further comprising a stepped portion between the first portion and the second portion. A semiconductor chip having a main surface and a back surface opposite to the main surface, comprising: a semiconductor chip having an integrated circuit and a plurality of external terminals formed on the main surface, and a plurality of leads each having an inner lead and an outer lead integrally formed with the inner lead, A plurality of leads each of which some of the inner leads are located on a main surface of the semiconductor chip, a plurality of bonding wires electrically connecting the plurality of external terminals and the inner leads of the plurality of leads and a main surface of the semiconductor chip, A resin body for sealing the inner leads of the plurality of leads and the plurality of bonding wires, and the thickness of the resin body on the back surface side of the semiconductor chip in the thickness direction of the semiconductor chip is the main surface side of the semiconductor chip. It is thinner than the thickness of the said resin body in the semiconductor device characterized by the above-mentioned. The semiconductor device of claim 5, wherein the inner lead has a first portion adhered to a main surface of the semiconductor chip and a second portion disposed on a main surface of the semiconductor chip and positioned in a region different from the first portion. A plurality of bonding wires are connected to the first portion of the inner lead. The semiconductor device according to claim 6, wherein a distance between the second portion and a main surface of the semiconductor chip in a thickness direction of the semiconductor chip is larger than a distance between the first portion and a main surface of the semiconductor chip. 7. The semiconductor device according to claim 6, wherein there is a stepped portion between the first portion and the second portion.