CN1143371C - Molded plastic type semiconductor device and its manufacturing process - Google Patents

Abstract

A method of manufacturing a resin-sealed semiconductor device in which a die pad has an area smaller than that of a semiconductor chip mounted on a main surface of the die pad, the semiconductor chip and the die pad being sealed in a molded resin body. The semiconductor chip and the die pad are arranged in the cavity of the mold so that the distance between the back of the die pad and the opposite inner surface of the cavity is narrower than the distance between the main surface of the semiconductor chip and the opposite inner surface of the cavity. thickness distance. The resin body is molded by simultaneously injecting resin into the cavity through the middle gate. Then the semiconductor chip does not move upward due to the resin injected into the space on the back side of the chip. Therefore, the yield of resin-sealed semiconductor devices can be improved since defects in which semiconductor chips, bonding wires, and the like are exposed outside the molding resin body are prevented.

Description

Molded plastic type semiconductor device and its manufacturing process

The present invention relates to a molded plastic type semiconductor device, in particular to a molded plastic type semiconductor device manufactured by transfer molding and a process technology which can be effectively applied to manufacture the device.

Molded plastic type semiconductor devices are manufactured by mounting a semiconductor chip on the chip mounting surface of a die pad (also called a pallet) supported on a lead frame body by supporting leads; External terminals on the main surface of the semiconductor chip and the inner section of the lead supported on the lead frame body; sealing the semiconductor chip, die pad, support lead, inner section of the lead, bonding wire, etc. with a plastic mold; from the lead frame Cutting the supporting lead and the outer section of the lead on the frame; then forming the outer section of the lead into a predetermined shape.

The above-mentioned plastic mold for molding a plastic type semiconductor device is manufactured according to transfer molding suitable for mass production. Specifically, the lead frame that has gone through the previous steps (die bonding step and wire bonding step) is placed between the upper and lower parts of the mold, while the semiconductor chip, die pad, supporting lead are placed in the cavity of the mold And the inner section of the lead wire and the bonding wire. The plastic mold is then created by pouring resin from the mold slots into the cavities under pressure through its runners and gates.

In the above-mentioned plastic mold manufacturing steps, in order to suppress the failure of filling the resin in the cavity, in other words, to suppress the generation of voids, it has been tried by disposing the semiconductor chip 2 and the die pad 3A in the cavity 11 as shown in FIG. 16 (schematically). sectional view) so that the distance L1 from the main surface of the semiconductor chip 2 to the inner wall surface of the cavity 11 opposite to the main surface is equal to the distance L1 from the back surface of the die pad 3A to the cavity 11 opposite to the back surface. The distance L2 of the inner wall surface is such that the fluidity of the resin flowing into the filling region 11A on the main surface side of the semiconductor chip 2 is equal to the fluidity of the resin flowing into the filling region 11B on the back side of the semiconductor chip 2 . In addition, it has also been attempted to simultaneously fill the resin into the semiconductor cavity 2 by using a center gate 12 (also called a vertical gate) extending above and below the lead frame 3 as a gate for controlling the amount of resin poured into the cavity 2 . In the filled region 11A on the main surface side and the filled region 11B on the back side of the chip 2,

In the above-mentioned molded plastic type semiconductor device, the die pad and the semiconductor chip are sealed with the plastic mold, so that water contained in the plastic mold tends to collect in the back surface of the die pad. Moisture accumulated on the back of the die pad evaporates and expands due to the heat generated by the temperature cycle test or the heat generated during packaging, and becomes the cause of plastic mold cracks (package cracks), where the temperature cycle test is a Environmental tests performed after completion of the product.

In order to overcome this technical problem, Japanese Patent Laid-Open No. Sho 63-204753 discloses a technology that makes the area of the die pad smaller than that of the semiconductor chip, and by using this technology, it is possible to suppress the accumulation of water in the resin of the plastic mold on the die. Phenomenon on the back of the pad. Therefore, plastic mold cracking (package cracking) due to moisture evaporation and expansion in the backside of the die pad can be prevented.

As shown in FIG. 17 (schematic cross-sectional view), when the area of the die pad 3A is made smaller than the area of the semiconductor chip 2, the filling region 11B on the back side of the semiconductor chip 2 thus becomes wider, which makes the area on the back side of the semiconductor chip 2 wider. The fluidity of the resin flowing in the filled region 11B on the side is higher than the fluidity of the resin flowing in the filled region 11A on the main surface side of the semiconductor chip 2 . In other words, the resin filling of the filling region 11B on the back surface side of the semiconductor chip 2 is completed earlier than the resin filling of the filling region 11A on the main surface side of the semiconductor chip 2 . As shown in FIG. 18 (schematic sectional view), the resin 1A filled in the filling region 11B on the back side of the semiconductor chip 2 pushes up the semiconductor chip 2, causing the semiconductor chip 2, bonding wires, etc. to emerge from the plastic mold, thereby causing The yield of molded plastic type semiconductor devices is significantly reduced.

On the other hand, in a resin molded type semiconductor device adopting a QFP (Quad Flat Package) structure, support leads are provided on the outer area of the corner of the semiconductor chip, and multiple leads are provided on the outer area of each side of the semiconductor chip. leads and multiple bond wires. In other words, the outer area of the corner of the semiconductor chip is larger than the outer area of each side of the semiconductor chip, so the fluidity of the resin is higher in the outer area of the corner of the semiconductor chip than that of each side of the semiconductor chip. Therefore, the bonding wires flow due to the resin flowing from the outer area of the corner to the outer area of each side of the semiconductor chip, and a short circuit occurs between two adjacent bonding wires, which causes damage to the molded plastic type semiconductor device. Yield drops significantly. The short circuit between these bonding wires is especially between the bonding wire connected to the first-level lead closest adjacent to the outer region of the corner of the semiconductor chip, and the bonding wire connected to the second lead adjacent to the first lead. significantly.

An object of the present invention is to provide a technique capable of improving the yield of molded plastic type semiconductor devices.

Another object of the present invention is to provide a technique capable of improving the yield in the manufacturing process of molded plastic type semiconductor devices.

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

Typical inventions disclosed in this application are briefly described below.

(1) A process for manufacturing a molded plastic type semiconductor device in which a die pad is formed to have an area smaller than that of a semiconductor chip mounted on a main surface of the die pad, and the semiconductor chip and The die pad is sealed with a plastic mold, and the process includes the following steps: mounting a semiconductor chip on the main surface of the die pad supported on the frame body of the lead frame by supporting leads; lead frame, and set the semiconductor chip and the die pad in the cavity of the mold so that the distance between the back side of the die pad and the inner wall surface of the cavity opposite to the back side of the die becomes larger than the distance between the main surface of the semiconductor chip and the The distance between the inner wall surfaces of the cavity opposite to the main surface of the semiconductor chip is as narrow as the thickness of the die pad; the resin is poured from the gate of the mold on the side of the semiconductor chip. The process also includes using the center gate extending above and below the lead frame as a gate of the mold and simultaneously pouring resin into the upper and lower portions of the cavity to form a plastic mold.

(2) A molded plastic type semiconductor device, wherein a plurality of external terminals are provided on at least one side on the main surface of a semiconductor chip and are arranged along the at least one side, and a plurality of leads are provided on one side of said semiconductor chip and arranged along the side, each of the plurality of external terminals is electrically connected to one end of each of the plurality of leads through a bonding wire, the semiconductor chip, the leads and the bonding wires are made of resin seal. In this molded plastic type semiconductor device, at least the distance between the end of the first-level lead closest to the corner of said semiconductor chip and the second-level lead adjacent to the first-level lead is formed wider than the other two lead ends. distance between.

According to clause (1), the filled region on the main surface side of the semiconductor chip has substantially the same volume as the filled region on the backside side, and each region is provided in a cavity so that the flow through the main surface of the semiconductor chip The fluidity of the resin in the filled region is almost equal to that of the resin flowing through the filled region on the back side. In addition, employing the middle gate can simultaneously supply resin to the filling region on the main surface side and the filling region on the back side of the semiconductor chip. Therefore, the resin filling of the filling region on the main surface side of the semiconductor chip and the resin filling of the filling region on the back side can be completed almost simultaneously, which can prevent the semiconductor chip from being pushed up by the resin filled into the filling region on the back side of the semiconductor chip. rise. As a result, semiconductor chips, bonding wires, etc. can be prevented from emerging from the plastic mold, and the yield of molded plastic type semiconductor devices can be improved,

According to the above-mentioned item (2) of the present invention, since the bonding wire connected to one end portion of the first-level lead in the outer region closest to the corner of the semiconductor chip is connected to the second-level lead connected to the adjacent first-level lead The distance between the other bonding wires at one end can be formed wider, and even if the bonding wires move due to resin flowing from the outer area of the corner of the semiconductor chip to the outer area of one side of the semiconductor chip, these bonds can be suppressed. Short circuit between wires. As a result, the yield of molded plastic type semiconductor devices can be improved.

Fig. 1 is a plan view of a molded plastic type semiconductor device of a first embodiment of the present invention, in which the upper part of the plastic mold has been removed.

Fig. 2 is a sectional view taken along line A-A of Fig. 1 .

Fig. 3 is a sectional view taken along line B-B of Fig. 1 .

Fig. 4 is a plan view of a lead frame used to manufacture the above molded plastic type semiconductor device.

Fig. 5 is a partial sectional view showing a process of manufacturing the above molded plastic type semiconductor device.

Fig. 6 is another partial sectional view showing the process of manufacturing the above molded plastic type semiconductor device.

Fig. 7 is a schematic sectional view showing resin flow.

Fig. 8 is another schematic sectional view showing resin flow.

Fig. 9 is a plan view of another lead frame used for manufacturing the above molded plastic type semiconductor device.

Fig. 10 is a plan view of still another lead frame used for manufacturing the above molded plastic type semiconductor device.

Fig. 11 is a plan view of a molded plastic type semiconductor device according to a second embodiment of the present invention, with the upper part of the plastic mold removed.

Fig. 12 is a partially enlarged cross-sectional view of Fig. 11 .

Fig. 13 is a plan view of a lead frame used to manufacture the above molded plastic type semiconductor device.

Fig. 14 is a partial plan view showing a modification of the above molded plastic type semiconductor device.

Fig. 15 is a plan view of a semiconductor chip showing a modification of the above molded plastic type semiconductor device.

Fig. 16 is a schematic sectional view showing a conventional problem.

Fig. 17 is another schematic sectional view showing a conventional problem.

Fig. 18 is still another schematic sectional view showing a conventional problem.

The composition of the present invention will be described below in conjunction with various embodiments.

In any of the drawings showing the embodiments, elements with the same function are denoted by the same reference numerals, and their repeated descriptions will be omitted.

(first embodiment)

In the molded plastic type semiconductor device of this embodiment, the semiconductor chip 2 is mounted on the chip mounting surface (main surface) of the die pad 3A, as shown in FIGS. 1 and 2 .

The semiconductor chip 2 has a planar shape, for example, a square plane with outer dimensions of 9 [mm]×9 [mm]. For example, it is mainly composed of a semiconductor substrate composed of single crystal silicon and an interconnection layer formed on the main surface of the substrate.

On the semiconductor chip 2, for example, logic circuitry or a hybrid circuitry combining logic circuitry and memory circuitry is mounted. Furthermore, on the main surface of the semiconductor chip 2, a plurality of external terminals (bonding pads) 2A are provided along each side of the main surface. Each external terminal 2A is formed on an upper interconnection layer among the interconnection layers of the semiconductor chip 2, and is composed of an aluminum (Al) film or an aluminum alloy film.

Outside each side of the semiconductor chip 2, a plurality of leads 3C are provided along each side. Each inner segment 3C1 of the plurality of leads 3C is electrically connected to each of the plurality of external terminals 2A provided on the main surface of the semiconductor chip 2 through a bonding wire 5 .

For the bonding wire 5, gold (Au) wire is used, for example. Alternatively, a wire having metal wires such as aluminum (Al) wires or copper (Cu) wires covered with an insulating resin may be used. The connection of the bonding wire 5 is performed by a bonding method using thermocompression bonding and ultrasonic vibration bonding.

Four support leads 3B are coupled to the die pad 3A. In the case of a lead frame, each of the four support leads 3B is used to support the die pad 3A on the frame body of the lead frame. The four support leads 3B support the die 3A at four points thereof so as to form a symbol X as a cross with the die pad 3A. The width of the support lead 3B is set to 0.4 [mm], for example.

The semiconductor chip 2, the die pad 3A, the support lead 3B, the inner section 3C1 of the lead 3C, the bonding wire 5, etc. are sealed by the plastic mold 1 formed by transfer molding. The plastic mold 1 is formed of, for example, biphenyl resin added with phenol hardener, silicone rubber, filler, etc. to reduce stress. The transfer molding method is a method that uses a mold equipped with grooves, runners, gates, cavities, etc., to pour resin from the grooves into the cavities through the runners and gates under pressure to form a plastic mold.

The planar shape of the plastic mold 1 is, for example, a square whose outer dimensions are 14 [mm]×14 [mm]. A plurality of outer sections 3C2 of leads 3C are arranged on the outside of each side of the plastic mold 1 . The outer sections 3C2 of the plurality of leads 3C are arranged along each side of the plastic mold 1, for example in the form of gull wings. In short, a molded plastic type semiconductor device according to the present invention is manufactured to have a QFP (Quad Flat Package) structure.

The planar shape of the die pad 3A is, for example, a circle whose outer dimension is 2-4 [mm] in diameter. In other words, the die pad 3A of the present embodiment is formed to have an area smaller than that of the semiconductor chip 2 . By forming the die pad 3A to have an area smaller than that of the semiconductor chip 2, it is possible to suppress the phenomenon that the moisture contained in the resin of the plastic mold 1 gathers on the back surface of the die pad 3A, thereby preventing the plastic mold from being damaged due to moisture evaporation and expansion. 1 cracked.

In the manufacturing steps of the plastic mold 1, even if the middle part of the bonding wire 5 hangs down, the die pad 3A can be prevented from being in contact with the bonding wire 5 because the die pad 3A does not exist outside the periphery of the semiconductor chip 2. . The longer the bonding wire 5 is, the more prominent the overhang of the middle part of the bonding wire 5 is.

On the other hand, when the area of the semiconductor chip 2 is reduced to the area of the die pad 3A, the die pad 3A also does not exist outside the periphery of the semiconductor chip 2 . Therefore, even if the middle portion of the bonding wire 5 hangs down, the die pad 3A is not brought into contact with the bonding wire 5, so semiconductor chips 2 having different external dimensions can be mounted.

The central area of the back surface opposite to the main surface of the semiconductor chip 2 is adhered and fixed to the chip mounting surface of the die pad 3A by the adhesive 4 . The adhesive 4 is made of, for example, an epoxy-based silver (Ag) paste material. In the bonding step of the semiconductor chip 2, the adhesive 4 is applied on the chip mounting surface of the die pad 3A using a multi-point coating method.

The supporting lead 3B is composed of a lead portion 3B1 and a lead portion 3B2, as shown in FIG. 3 . The lead portion 3B1 is provided at the same position in the mold thickness direction (vertical direction) as the inner section 3C1 of the lead 3C shown in FIG. . In the molded plastic type semiconductor device of this embodiment, the chip mounting surface of the die pad 3A descends from the upper surface (bonding surface) of the inner section 3C1 of the lead 3C in the thickness direction of the mold.

In the plastic mold 1, as shown in FIGS. 2 and 3, the thickness L1 of the resin on the main surface of the semiconductor chip 2 is thicker than the thickness of the resin on the back surface of the die pad 3A by as much as the thickness of the die pad 3A. In other words, the semiconductor chip 2 is disposed almost at the center of the plastic mold 1 in the thickness direction of the plastic mold 1 .

A molded plastic type semiconductor device having the above structure is manufactured by a process using the lead frame 3, as shown in FIG.

The lead frame 3 has a die pad 3A, four support leads 3B, a plurality of leads 3C, and the like, each provided in an area defined by the frame body 3E. The die pad 3A is coupled to the frame body 3E through four support leads 3B. A plurality of lead wires 3C are connected to the frame body 3E, and are also connected to each other through a link (barrier bar) 3D.

The lead wire 3C is composed of an inner section 3C1 to be sealed by the plastic mold 1 and an outer section 3C2 formed into a predetermined shape. The support lead 3B is composed of a lead portion 3B1 and a lead portion 3B2. The lead portion 3B1 is provided at the same position in the thickness direction (vertical direction) of the mold as the inner section 3C1 of the lead 3C, and the lead portion 3B2 is provided at the same position as the die pad 3A in the thickness direction (vertical direction) of the mold.

The lead frame 3 is made of, for example, an iron (Fe)-nickel (Ni)-based alloy, copper (Cu), or a copper-based alloy. Such a lead frame is formed by etching or punching a sheet material into a predetermined pattern, and then punching the supporting leads 3B.

In an area close to the frame body 3E where the support lead 3B is connected to the lead frame 3, a through hole 3F is formed for injection of resin. During the manufacture of the plastic mold 1 , such a through hole divides the flow of resin supplied from the groove of the mold through the runner into two streams, ie, two streams above and below the lead frame 3 .

The smaller the outer diameter of the die pad 3A, the longer the support leads 3B become, which easily moves the die pad in the vertical direction. In addition, as the number of pins increases, the support lead 3B becomes narrower, and the die pad 3A becomes easier to move in the vertical direction. In addition, the thinner the plastic mold 1 is, the thinner the support leads 3B are, which makes it easier to move the die pad 3A in the vertical direction.

Next, a method of manufacturing the above-mentioned molded plastic type semiconductor device will be described.

First, a lead frame 3 as shown in FIG. 4 is prepared.

Then, the adhesive 4 is applied on the chip mounting surface (main surface) of the die pad 3A supported on the frame body 3E of the lead frame 3 by the support lead 3B by a multi-point coating method.

The semiconductor chip 2 is mounted on the chip mounting surface of the die pad 3A by the adhesive 4 . The semiconductor chip 2 is attached so as to be fixed to the chip mounting surface of the die pad 3A by the adhesive 4 .

The external terminal 2A of the semiconductor chip 2 and the inner section 3C1 of the lead 3C supported to the frame body of the lead frame 3 are electrically connected by the bonding wire 5 .

As shown in FIGS. 5 and 6, the lead frame 3 is arranged between the upper part 10A and the lower part 10B of the mold 10, and the semiconductor chip 2 and the die pad 3 are arranged in the cavity 11 of the mold 10, so that the die pad The distance L2 between the back side of 3A and the inner wall surface of the cavity 11 opposite to the back side is narrower than the distance L1 between the main surface of the semiconductor chip 2 and the inner wall surface of the cavity 11 opposite to the main surface by as much as The length of the thickness of the die pad 3A. By making the distance L2 from the back side of the die pad 3A to the inner wall surface of the cavity 11 opposite to the back side be greater than the distance L2 from the main surface of the semiconductor chip 2 to the inner wall surface of the cavity 11 opposite to the main surface The semiconductor chip 2 and the die pad 3A are arranged such that the distance L1 between them is as narrow as the length equivalent to the thickness of the die pad 3A, and the filling region 11A on the main surface side of the semiconductor chip 2 has almost the same thickness as the filling region 11B on the back side thereof. volume, so that the fluidity of the resin flowing in the filled region 11A on the main surface side of the semiconductor chip 2 can be made almost equal to the fluidity of the resin flowing through the filled region 11B on the back side.

Incidentally, in the cavity 11, in addition to the semiconductor chip 2 and the die pad 3A, support leads 3B, inner segments 3C1 of the leads 3C, bonding wires 5, and the like are provided. In addition to the cavity 11, the mold 10 is also equipped with a groove, a runner, and a gate 12 in the middle. The middle gate 12 exists above and below the lead frame 3 so that the resin can be simultaneously supplied to the filling region 11A on the main surface side of the semiconductor chip 2 and the filling region 11B on the back side of the semiconductor core chip disposed in the cavity 11 . The middle gate 12 is provided near the area where the support lead 3B is connected to the frame body 3E of the lead frame 3 .

Then, resin is poured into the cavity 11 through the central gate 12 present above and below the lead frame 3 under pressure. Resin is supplied from the groove of the mold 10 to the center gate 12 through runners. Figures 7 and 8 show the flow of resin during this step. The resin 1A injected from the middle gate 12 is sent into the filling region 11A on the main surface of the semiconductor chip 2 and the filling region 11B on the back side thereof almost simultaneously. The filling of the filling region 11A with the resin 1A is completed almost simultaneously with the filling of the filling region 11B, as shown in FIG. 8 . In other words, the semiconductor chip 2 is not lifted up by the resin 1A filled to the filling region 11A on the back side of the semiconductor chip 2 .

The outer section 3C2 supporting the lead 3B and the lead 3C is cut from the frame body 3E of the lead frame 3, and then the outer section 3C2 of the lead 3C is formed into a gull-wing shape, thereby completing the molded plastic shown in FIGS. 1, 2 and 3 at the same time. type semiconductor devices.

In this embodiment, a process for manufacturing a molded plastic type semiconductor device in which the area of the die pad 3A is formed smaller than the area of the semiconductor chip 2 to be mounted on the main surface thereof, and the semiconductor chip 2 and The die pad 3A is sealed by a plastic mold. This process includes the steps of: mounting the semiconductor chip 2 on the main surface of the die pad 3A supported on the frame body 3E of the lead frame 3 by the supporting lead 3B; disposing said lead between the upper part 10A and the lower part 10B of the mold 10 Frame 3; semiconductor chip 2 and die pad 3A are set such that distance L2 from the back side of die pad 3A to the inner wall surface of cavity 11 opposite to the back side becomes larger than from the main surface of semiconductor chip 2 to The distance L1 between the inner wall surfaces of the cavity 11 opposite to the main surface is narrow by a length corresponding to the thickness of the die pad 3A; the resin is poured into the cavity 11 from the semiconductor chip side. In addition, the resin pouring step includes pouring resin into the cavity 11 from the center gate 12 existing above and below the lead frame 3 , thereby forming the plastic mold 1 .

According to the above process, the volume of the filling region 11A provided on the main surface side of the semiconductor chip 2 of the cavity 11 is almost equal to the volume of the filling region 11B on the back side, so that the resin flowing through the filling region 11A on the main surface side of the semiconductor chip 2 The fluidity of is almost equal to the fluidity of the resin flowing through the filling region 11B on the back side thereof. Using the middle gate 12 can simultaneously supply resin to the filling region 11A on the main surface side and the filling region 11B on the back side. Therefore, the resin filling of the filling region 11A on the main surface side of the semiconductor chip 2 and the resin filling of the filling region 11B on the back side of the semiconductor chip 2 can be completed almost simultaneously, so the semiconductor chip 2 is prevented from being filled up to the back side of the semiconductor chip 2. area of resin jacking up. Thus, the semiconductor chips 2, bonding wires 5, etc. can be prevented from emerging from the plastic mold 1, and the yield of molded plastic type semiconductor devices can be improved.

By disposing the die pad 3A lower than the inner section 3C1 of the lead 3C supported by the frame body 3E of the lead frame 3 in the plastic mold thickness direction, the flow of the resin flowing in the filling region on the main surface side of the semiconductor chip 2 can be made The fluidity is substantially equal to the fluidity of the resin flowing in the filling region 11B on the back side.

Incidentally, a molded plastic type semiconductor device can be produced by a manufacturing process using a lead frame 3 having a die pad 3A formed in a square shape, as shown in FIG. 9 . Similar advantages can be obtained by employing such a process of the lead frame 3 .

A molded plastic type semiconductor device can also be produced by a manufacturing process using a lead frame 3 having a die pad 3A formed in an X-shaped plane, as shown in FIG. 10 . Similar advantages can be obtained by employing such a process of the lead frame 3 .

(second embodiment)

The molded plastic type semiconductor device according to this embodiment has the semiconductor chip 2 mounted on the chip mounting surface (main surface) of the die pad 3A, as shown in FIGS. 11 and 12 .

The semiconductor chip 2 has a planar shape, for example, a square with outer dimensions of 9 [mm]×9 [mm]. On the main surface of the semiconductor chip 2, a plurality of external terminals (bonding pads) 2A are provided along each side of the main surface.

In the outer area of each side of the semiconductor chip 2, a plurality of leads 3C arranged along each side are provided. The plurality of external terminals 2A provided on the main surface of the semiconductor chip 2 are electrically connected to the inner segments 3C1 of the plurality of leads 3C through bonding wires.

Four support leads 3B are coupled to the die pad 3A. In the case of a lead frame, these four support leads 3B are used to support the die pad 3A on the frame body of the lead frame. These four support leads 3B are respectively provided on the outer areas of the four corners of the semiconductor chip 2 .

The semiconductor chip 2, the die pad 3A, the support lead 3B, the inner section 3C1 of the lead 3C, the bonding wire 5, etc. are sealed by the plastic mold 1 formed by transfer molding.

The planar shape of the plastic mold 1 is, for example, a square whose outer dimensions are 14 [mm]×14 [mm]. A plurality of outer sections 3C2 of leads 3C are arranged on the outside of each side of the plastic mold 1 . The outer sections 3C2 of the plurality of leads 3C are arranged along each side of the plastic mold 1 in a gull-wing shape, for example. The molded plastic type semiconductor device according to the present embodiment is thus manufactured to have a QFP (Quad Flat Package) structure.

The planar shape of the die pad 3A is, for example, a circle whose outer dimension is 2-4 [mm] in diameter. In other words, the die pad 3A is formed to have a smaller area than the semiconductor chip 2 .

Each supporting lead 3B is constituted by one lead portion ( 3B1 ) and the other lead portion ( 3B2 ) similarly to the first embodiment described above.

Regarding the plurality of leads 3C arranged in the outer area of each side of the semiconductor chip 2, from one end portion of the first-level lead 3CA adjacent to the outer area of the corner of the semiconductor chip 2 to the second-level lead 3CA adjacent to the first-level lead 3CA The distance P between the secondary leads 3CB is wider than the distance between any other two leads 3C. By making the distance P from one end portion of the first-level lead 3CA in the outer region closest to the corner of the semiconductor chip 2 to the second-level lead 3CB adjacent to the first-level lead 3CA wider than any other two as described above, The distance between the leads 3C can widen the bonding wire 5 connected to one end of the first-level lead 3CA in the outer region closest to the corner of the semiconductor chip 2, and the bonding wire 5 connected to the second-level lead 3CB adjacent to the first-level lead 3CA. The spacing between the other bonding wire 5 at one end of the

The molded plastic type semiconductor device constructed as above can be manufactured by a process using the lead frame 3 shown in FIG. 13 .

The lead frame 3 has a die pad 3A, four supporting leads 3B, and a plurality of leads 3C arranged in an area defined by the frame body 3E. The die pad 3A is coupled to the frame body 3E through four support leads 3B. A plurality of lead wires 3C are connected to the frame body 3E, and are also connected to each other through a link (barrier bar) 3D.

The frame body 3E is a square plane. Each of the leads 3C is arranged along each side of the frame body 3E, and the four supporting leads 3B are arranged along the diagonal of the frame body 3E.

Regarding the plurality of leads 3C arranged along each side of the frame body 3E. The distance between one end of the first-level lead 3CA closest to the support lead 3B to one end of the second-level lead 3CB adjacent to the first-level lead 3CA is formed wider than the distance between the ends of any other two leads 3C.

The manufacturing process of the above-mentioned molded plastic type semiconductor device will be described below.

First, a lead frame 3 as shown in FIG. 13 is prepared.

Then, the semiconductor chip 2 is mounted by the adhesive 4 on the chip mounting surface of the die pad 3A supported on the frame body 3E of the lead frame 3 by the support lead 3B.

The external terminal 2A of the semiconductor chip 2 and one end of the lead 3C (one end of the inner segment 3C1 ) supported to the frame body of the lead frame 3 are electrically connected by the bonding wire 5 .

As in the first embodiment, the lead frame 3 is placed between the upper part 10A and the lower part 10B of the mold 10, and the semiconductor chip 2, the die pad 3A, the supporting lead 3B, the inner segment 3C1 of the lead 3C, the bonding wire, etc. Set in the cavity of the mold.

Then, resin is injected from the groove of the mold 10 through runners and gates, thereby forming the plastic mold 1 . In this step, the support leads 3B are provided in the outer area of the corner of the semiconductor chip 2 , and the plurality of leads 3C and the plurality of bonding wires 5 are provided in the outer area of each side of the semiconductor chip 2 . In other words, the outer area of one corner of the semiconductor chip 2 is larger than the outer area of one side of the semiconductor chip 2 so that the fluidity of the resin in the outer area of one corner of the semiconductor chip 2 is higher than that of the outer area of one side of the semiconductor chip 2. area. Therefore, the bonding wire 5 tends to flow due to the resin flowing from the outer region of one corner to the outer region of one side of the semiconductor chip 2 . Since the bonding wire 5 connected to one end of the first-level lead 3CA of the outer region closest to the corner of the semiconductor chip 2 is connected to the other end of the second-level lead 3CB adjacent to the first-level lead 3CA, A wide pitch between the bonding wires 5 can suppress short circuits between the bonding wires even if the bonding wires flow due to resin flow from the outer region of the corner to the outer region of one side of the semiconductor chip 2 .

The molded plastic type semiconductor device shown in FIG. .

In this embodiment, a process for manufacturing a molded plastic type semiconductor device in which a plurality of external terminals 2A are provided on at least one side of a main surface of a semiconductor chip and arranged at least along the at least one side A plurality of leads 3C are arranged outside one side of the semiconductor chip 2 and arranged along the side; one end of each of the plurality of leads 3C is electrically connected to a plurality of external terminals 2A through a bonding wire 5; each lead of the semiconductor chip 2 and bonding wires etc. are sealed by plastic mold 1. In this molded plastic type semiconductor device, the distance P between one end portion of the first-level lead 3CA in the outer region closest to the corner of the semiconductor chip 2 and the second-level lead 3CB adjacent to the first-level lead 3CA is formed to be as wide as possible. to the distance between the ends of any other two leads 3C.

The above structure can widen the bonding wire 5 connected to one end portion of the first-level lead 3CA of the outer region closest to the corner of the semiconductor chip 2, and the bonding wire 5 connected to one end portion of the second-level lead 3CB adjacent to the first-level lead 3CA. Another spacing between bonding wires 5 . Therefore, even if the bonding wires flow due to the resin flowing from the outer region of the corner of the semiconductor chip 2 to the outer region of one side during the manufacturing step of the plastic mold, short circuit between the bonding wires 5 can be prevented. Therefore, the yield of molded plastic type semiconductor devices can be improved.

When reducing the outer dimensions of the semiconductor chip 2, this reduction is accompanied by an increase in the length of the bonding wire 5. Even if the distance P between one end portion of the first-level lead 3CA and one end portion of the second-level lead 3CB widens, and the bonding wire 5 becomes longer due to the reduction in the outer size of the semiconductor chip 2, it is possible to prevent contact with the first level lead 3CA. A short circuit between the bonding wire 5 connected to one end of the level lead 3CA and the other bonding wire 5 connected to one end of the second level lead 3CB.

Incidentally, among the plurality of external terminals 2A arranged on and along one side of the main surface of the semiconductor chip 2, as shown in FIG. In contrast, the distance P between the external terminal 2A1 closest to the corner of the semiconductor chip 2 and the external terminal 2A2 adjacent to the external terminal 2A1 is widened. In addition, in this case, the distance between the bonding wire 5 connected to one end of the first-level lead 3CA and the other bonding wire 5 connected to the second-level lead 3CB can be widened, so that it is possible to suppress the bonding of these bonding wires. 5 short circuits.

In addition, the fluidity of the resin flowing from the outer region at the corner of the semiconductor chip 2 to the outer region at one side of the semiconductor chip becomes gradually lower toward the center of the outer region at one side of the semiconductor chip 2 . As shown in FIG. 15, with respect to the external terminals 2A arranged on one side of the main surface of the semiconductor chip 2 and arranged along the side, it is therefore possible to widen the two sides clockwise from the center of one side of the semiconductor chip 2 toward its corner. Each distance between adjacent external terminals 2A. In this case, any short circuit between two adjacent bonding wires 5 can be suppressed without significantly increasing the outer size of the semiconductor chip because the distance between the two bonding wires 5 changes from the semiconductor The reason why the center of one side of the chip 2 can gradually become wider toward its corner.

The invention accomplished by the present inventor has been specifically introduced above in conjunction with the above-mentioned embodiments. However, it should be understood that the present invention is not limited to or by these embodiments, and modifications can be made without departing from its essence.

The present invention can improve the yield of molded plastic type semiconductor devices.

Claims (42)

1. A method of manufacturing a molded plastic type semiconductor device in which a die pad is formed to have an area smaller than that of a semiconductor chip mounted on a main surface of the die pad, the semiconductor chip and the die pad is sealed with a plastic mold, and the manufacturing method includes the following steps: (a) mounting a semiconductor chip on a major surface of a die pad supported on a frame body of a lead frame by support leads; (b) disposing the lead frame between the upper part and the lower part of the mold, and disposing the semiconductor chip and the die pad in the cavity of the mold so that the back side of the die pad is aligned with the back side of the die pad The distance between the inner wall surfaces of the opposite cavity becomes narrower than the distance between the main surface of the semiconductor chip and the inner wall surface of the cavity opposite to the main surface of the semiconductor chip by a length equivalent to the thickness of the die pad (3A); (c) Pouring resin from a gate of the mold on the side of the semiconductor chip, thereby sealing the semiconductor chip and the die pad with a resin film. 2. The manufacturing method according to claim 1, wherein said gate is defined by upper and lower parts of said lead frame. 3. The manufacturing method according to claim 1, wherein the die pad is positioned lower than an inner section of the lead supported on a frame body of the lead frame in a thickness direction of the plastic mold. 4. The manufacturing method according to claim 1, wherein the die pad is formed to have a circular plane, a square plane, or an X-shaped plane. 5. The manufacturing method according to claim 1, wherein said gate is provided near a region where a supporting lead is connected to said lead frame body. 6. A molded plastic type semiconductor device, wherein a plurality of external terminals are arranged on at least one side of the main surface of a semiconductor chip and arranged along the at least one side, and a plurality of leads are arranged on one side of the semiconductor chip outside, and arranged along the side, each of the plurality of external terminals is electrically connected to one end of each of the plurality of leads through a bonding wire, and the semiconductor chip, each lead and the bonding wire Sealing with resin, wherein at least the distance between one end of the lead closest to the corner of the semiconductor chip and one end of the lead adjacent to the lead is formed wider than the distance between the other two lead ends. 7. A molded plastic type semiconductor device, wherein a plurality of external terminals are arranged on at least one side of a main surface of a semiconductor chip and arranged along the at least one side, and a plurality of leads are arranged on one side of said semiconductor chip outside, and arranged along the side, each of the plurality of external terminals is electrically connected to one end of each of the plurality of leads through a bonding wire, and the semiconductor chip, each lead and the bonding wire Sealing with resin, wherein at least a distance between an external terminal closest to a corner of the semiconductor chip and another external terminal adjacent to the external terminal is formed wider than a distance between the other two external terminals. 8. A molded plastic type semiconductor device, wherein a plurality of external terminals are arranged on at least one side of a main surface of a semiconductor chip and are arranged along the at least one side, and a plurality of leads are arranged on one side of said semiconductor chip outside, and arranged along the side, each of the plurality of external terminals is electrically connected to one end of each of the plurality of leads through a bonding wire, the external terminals, each lead and the bonding wire Sealing with resin, wherein the distance between the plurality of external terminals gradually widens from the center of one side of the semiconductor chip toward the corner of the semiconductor chip. 9. The molded plastic type semiconductor device according to claim 6, wherein an outer portion of the corner portion of the semiconductor chip is provided with a die extending from the corner portion toward the outside thereof and connected to a die pad on which the semiconductor chip is to be mounted. Support leads. 10. The molded plastic type semiconductor device according to claim 6, wherein said die pad is formed to have a smaller area than said semiconductor chip. 11. A method of manufacturing a semiconductor device, comprising the steps of: (a) providing a lead frame having a first surface and a second surface opposite to the first surface, the lead frame having a die pad, support leads formed continuously with the die pad, and inner segment leads each and a plurality of leads of an outer segment lead formed continuously with the inner segment lead, each of the support leads having an offset portion such that the first surface of the die pad faces toward each of the plurality of leads a side of the second surface of the inner segment lead other than the first surface side of the inner segment lead of each of the plurality of leads; (b) mounting a semiconductor chip on the die pad, the semiconductor chip having a plurality of semiconductor elements and bonding pads formed on its main surface and the back surface opposite to the main surface, the size of the semiconductor chip being larger than the size of the die pad, the semiconductor chip being mounted such that the back side of the semiconductor chip faces the first surface of the die pad; (c) respectively electrically connecting the inner segment leads of the plurality of leads and the bonding pads of the semiconductor chip through a plurality of bonding wires; (d) setting the lead frame with the semiconductor chip in a mold so that the distance between the main surface of the semiconductor chip and the inner side of the cavity upper part of the mold is in the thickness direction of the semiconductor chip substantially equal to the distance between the back side of the semiconductor chip and the inner side of the cavity lower part of the mold; (e) injecting resin into the cavity of the mold by transfer molding, thereby sealing the semiconductor chip, the plurality of bonding wires, the inner sections of the plurality of leads with the resin film leads as well as the die pad. 12. The manufacturing method according to claim 11, wherein said step (e) is performed such that the thickness of said resin between said main surface of said semiconductor chip and said cavity upper inner side of said mold is within the thickness of said semiconductor chip. The thickness direction of the chip is substantially equal to the thickness of the resin between the back surface of the semiconductor chip and the inner side of the cavity lower portion of the mold. 13. A method of manufacturing a semiconductor device, comprising the steps of: (a) supply lead frames and semiconductor chips, The lead frame has a first surface and a second surface opposite to the first surface, the lead frame has a die pad, support leads formed continuously with the die pad, and each has an inner segment lead and is connected to the die pad. a plurality of leads of outer lead segments formed continuously of the inner lead leads, each of the support leads having an offset portion such that the first surface of the die pad faces the inner lead of each of the plurality of leads a side of the second surface of a segment lead other than a side of the first surface of the inner segment lead of each of the plurality of leads, The semiconductor chip has a plurality of semiconductor elements and bonding pads formed on its main surface and a back surface opposite to the main surface, the size of the semiconductor chip is larger than that of the die pad, the semiconductor chip is Mounted so that the back side of the semiconductor chip faces the first surface of the die pad, the offset portion of the support lead is formed such that the inner segment lead is substantially located on the semiconductor chip center position of the thickness; (b) respectively electrically connecting the inner segment leads of the plurality of leads and the bonding pads of the semiconductor chip through a plurality of bonding wires; (c) disposing said lead frame with said semiconductor chip in a mold; (d) injecting resin into the concave cavity of the mold by transfer molding, thereby sealing the semiconductor chip, the plurality of bonding wires, the inner sections of the plurality of leads with the resin film leads as well as the die pad. 14. A method of manufacturing a semiconductor device, comprising the steps of: (a) providing a lead frame having a first surface and a second surface opposite to the first surface, the lead frame having a die pad, support leads formed continuously with the die pad, and inner segment leads each and a plurality of leads of an outer segment lead formed continuously with the inner segment lead, each of the support leads having an offset portion such that the first surface of the die pad faces toward each of the plurality of leads a side of the second surface of the inner segment lead other than the first surface side of the inner segment lead of each of the plurality of leads; (b) mounting a semiconductor chip on the die pad, the semiconductor chip having a plurality of semiconductor elements and bonding pads formed on its main surface and the back surface opposite to the main surface, the size of the semiconductor chip being larger than the size of the die pad, the semiconductor chip being mounted such that the back side of the semiconductor chip faces the first surface of the die pad; (c) respectively electrically connecting the inner segment leads of the plurality of leads and the bonding pads of the semiconductor chip through a plurality of bonding wires; (d) disposing the lead frame with the semiconductor chip in a mold such that a first distance between the back surface of the semiconductor chip and the inner side of the cavity lower part of the mold is in the thickness direction of the semiconductor chip is smaller than a second distance between the main surface of the semiconductor chip and the inner side of the cavity upper part of the mold; (e) injecting resin into the cavity of the mold by transfer molding, thereby sealing the semiconductor chip, the plurality of bonding wires, the inner sections of the plurality of leads with the resin film leads as well as the die pad. 15. The manufacturing method according to claim 14, wherein the difference between the first distance and the second distance is the thickness of the die pad. 16. A method of manufacturing a semiconductor device, comprising the steps of: (a) providing a lead frame having a first surface and a second surface opposite to the first surface, the lead frame having a die pad, support leads formed continuously with the die pad, and inner segment leads each and a plurality of leads of an outer segment lead formed continuously with the inner segment lead, each of the support leads having an offset portion such that the first surface of the die pad faces toward each of the plurality of leads a side of the second surface of the inner segment lead other than the first surface side of the inner segment lead of each of the plurality of leads; (b) mounting a semiconductor chip on the die pad, the semiconductor chip having a plurality of semiconductor elements and bonding pads formed on its main surface and the back surface opposite to the main surface, the size of the semiconductor chip being larger than the size of the die pad, the semiconductor chip being mounted such that the back side of the semiconductor chip faces the first surface of the die pad; (c) respectively electrically connecting the inner segment leads of the plurality of leads and the bonding pads of the semiconductor chip through a plurality of bonding wires; (d) disposing the lead frame with the semiconductor chip in a mold such that a first distance between the back surface of the semiconductor chip and the inner side of the cavity lower part of the mold is in the thickness direction of the semiconductor chip smaller than the second distance between the main surface of the semiconductor chip and the upper inner side of the cavity of the mold, the mold has an upper mold, a lower mold and a gate portion for injecting molding material, the Both the upper mold and the lower mold are formed with the gate portion; (e) injecting resin into the cavity of the mold from the gate portion by transfer molding, thereby sealing the semiconductor chip, the plurality of bonding wires, the plurality of The inner segment lead of the lead and the die pad. 17. The manufacturing method according to claim 14, wherein said resin is formed in a quadrangular shape, and said outer segment leads protrude from four sides of said resin. 18. The manufacturing method according to claim 17, further comprising a step of forming said outer segment lead in a gull-wing shape for surface mounting on a printed circuit board after step (e). 19. A method of manufacturing a semiconductor device, comprising the steps of: (a) providing a semiconductor chip having a plurality of semiconductor elements and bonding pads formed on its main surface and a back surface opposite to the main surface, and a lead frame having a die pad, and The support leads formed continuously on the die pad and a plurality of leads each having an inner segment lead and an outer segment lead formed continuously with the inner segment lead, the ends of the inner segment leads of the plurality of leads are arranged to Surrounding the die pad in plan view, each of the support leads has an offset portion such that the upper surface of the die pad is lower than each of the plurality of leads in the thickness direction of the lead frame. an upper surface of the end portion of the inner segment lead, the size of the die pad is smaller than the size of the semiconductor chip; (b) mounting the semiconductor chip on the die pad such that the back surface of the semiconductor chip is bonded to the upper surface of the die pad and the inner segments of the plurality of leads are the ends of the leads surround the semiconductor chip near the sides of the semiconductor chip; (c) electrically connecting the ends of the inner segment leads of the plurality of leads and the bonding pads of the semiconductor chip through a plurality of bonding wires; (d) disposing the lead frame with the semiconductor chip in a mold such that the distance between the lower surface of the die pad and the inner side of the cavity lower part of the mold is in the thickness direction of the semiconductor chip is smaller than the distance between the main surface of the semiconductor chip and the inner side of the cavity upper part of the mold; and (e) injecting resin into the concave cavity of the mold from the gate of the mold located on one side of the semiconductor chip by transfer molding, thereby sealing the semiconductor chip, the The plurality of bonding wires, the inner section of the plurality of leads, and the die pad. 20. The manufacturing method according to claim 19, wherein each of said supporting leads has said offset portion so that said end portion of said inner section lead of said leads is positioned at said semiconductor chip in step (a). within the thickness range. 21. The manufacturing method according to claim 19, wherein said resin is formed in a quadrangular shape, and said outer segment leads of said leads protrude from four sides of said resin. 22. The manufacturing method according to claim 21, further comprising a step of forming each of said outer segment leads of said leads in a gull-wing shape for surface mounting on a printed circuit board after step (e). 23. The manufacturing method according to claim 19, wherein said step (e) is performed such that the thickness of said resin between said main surface of said semiconductor chip and said cavity upper inner side of said mold is within the thickness of said semiconductor chip. The thickness direction of the chip is substantially equal to the thickness of the resin between the back surface of the semiconductor chip and the inner side of the cavity lower portion of the mold. 24. A method of manufacturing a semiconductor device, comprising the steps of: (a) providing a semiconductor chip having a plurality of semiconductor elements and bonding pads formed on its main surface and a back surface opposite to the main surface, and a lead frame having a die pad, and The support leads formed continuously on the die pad and a plurality of leads each having an inner segment lead and an outer segment lead formed continuously with the inner segment lead, the ends of the inner segment leads of the plurality of leads are arranged to Surrounding the die pad in plan view, each of the support leads has an offset portion such that the upper surface of the die pad is lower than each of the plurality of leads in the thickness direction of the lead frame the upper surface of the end portion of the inner segment lead, the size of the die pad is smaller than the size of the semiconductor chip; (b) mounting the semiconductor chip on the die pad such that the back surface of the semiconductor chip is bonded to the upper surface of the die pad and the inner segments of the plurality of leads are the ends of the leads surround the semiconductor chip near the sides of the semiconductor chip; (c) electrically connecting the ends of the inner segment leads of the plurality of leads and the bonding pads of the semiconductor chip through a plurality of bonding wires; (d) setting the lead frame with the semiconductor chip in a mold so that the distance between the main surface of the semiconductor chip and the inner side of the cavity upper part of the mold is in the thickness direction of the semiconductor chip substantially equal to the distance between the backside of the semiconductor chip exposed from the die pad and the inner side of the cavity lower portion of the mold; and (e) injecting resin into the concave cavity of the mold from the gate of the mold located on one side of the semiconductor chip by transfer molding, thereby sealing the semiconductor chip, the The plurality of bonding wires, the inner section of the plurality of leads, and the die pad. 25. The manufacturing method according to claim 24, wherein each of said support leads has said offset portion so that said end portion of said inner section lead of said leads is positioned at said semiconductor chip in step (a). within the thickness range. 26. The manufacturing method according to claim 24, wherein said resin is formed in a quadrangular shape, and said outer segment leads of said leads protrude from four sides of said resin. 27. The manufacturing method according to claim 26, further comprising, after step (e), the step of forming each of said outer segment leads of said leads in a gull-wing shape for surface mounting on a printed circuit board. 28. A method of manufacturing a semiconductor device, comprising the steps of: (a) providing a semiconductor chip having a plurality of semiconductor elements and bonding pads formed on its main surface and a back surface opposite to the main surface, and a lead frame having a die pad, and The support leads formed continuously on the die pad and a plurality of leads each having an inner segment lead and an outer segment lead formed continuously with the inner segment lead, the ends of the inner segment leads of the plurality of leads are arranged to Surrounding the die pad in plan view, the size of the die pad is smaller than the size of the semiconductor chip; (b) mounting the semiconductor chip on the die pad such that the semiconductor chip is bonded to the die pad and the end of the inner segment lead of the plurality of leads surrounds the semiconductor chips; (c) electrically connecting the ends of the inner segment leads of the plurality of leads and the bonding pads of the semiconductor chip through a plurality of bonding wires; (d) disposing the lead frame with the semiconductor chip in a mold having an upper mold and a lower mold such that the semiconductor chip, the plurality of bonding wires and the die pad are positioned by the mold of the mold. in the cavity defined by the upper die and the lower die, and at the boundary between the inner segment lead and the outer segment lead of each of the plurality of leads with the upper die of the die a mold and a lower mold clamp the lead frame, the mold has a gate portion for injecting molding material into the cavity, and both the upper mold and the lower mold are formed with the gate portion; (e) injecting resin into the cavity of the mold from the gate portion of the mold toward one side of the semiconductor chip by transfer molding, thereby sealing the semiconductor with the resin film A chip, the plurality of bonding wires, the inner segment of the plurality of leads, and the die pad. 29. The manufacturing method according to claim 28, wherein each of said support leads has an inner section and an outer section formed continuously with said inner section, and said upper and lower molds of said mold are used in step (d) to The support leads are clamped at a boundary between the inner section and the outer section of each of the support leads, and the gate portion of the mold is located at one of the support leads. 30. The manufacturing method according to claim 29, wherein said resin is formed in a quadrangular shape, said outer sections of said supporting leads protrude outward from four corners of said resin, said outer sections of said plurality of leads Segment leads protrude outward from the four sides of the resin. 31. The manufacturing method according to claim 30, wherein said gate portion of said mold is located at one of four corners of said resin. 32. The manufacturing method according to claim 31, further comprising, after step (e), the step of forming each of said outer segment leads of said plurality of leads in a gull-wing shape for surface mounting on a printed circuit board. 33. The manufacturing method according to claim 32, further comprising the step of cutting said support lead to separate said outer section of said support lead at said boundary after step (e). 34. The manufacturing method according to claim 28, wherein said back surface of said semiconductor chip is bonded to a surface of said die pad with an adhesive in said step (b). 35. A method of manufacturing a semiconductor device, comprising the steps of: (a) provide semiconductor chips and lead frames, The semiconductor chip has a plurality of semiconductor elements and bonding pads formed on its main surface and a back surface opposite to the main surface, The lead frame has a die pad, a support lead formed continuously with the die pad, and a plurality of leads each having an inner segment lead and an outer segment lead formed continuously with the inner segment lead, the plurality of leads having One end of the inner segment lead is disposed to surround the die pad in plan view, and each of the support leads has an offset portion such that an upper surface of the die pad is lower than the die pad in a thickness direction of the lead frame. an upper surface of each of the one ends of the plurality of leads, the size of the die pad is smaller than the size of the semiconductor chip; (b) mounting the semiconductor chip on the die pad such that the back surface of the semiconductor chip is bonded to the upper surface of the die pad and the one ends of the plurality of leads are Surrounding the semiconductor chip near sides of the semiconductor chip; (c) electrically connecting the one end of the plurality of leads and the bonding pad of the semiconductor chip through a plurality of bonding wires; (d) setting the lead frame with the semiconductor chip in a mold having an upper mold and a lower mold such that the semiconductor chip, the plurality of bonding wires, the die pad, and the plurality of leads The one end of the lead wire is located in a cavity defined by the upper mold and the lower mold of the mold, and the upper mold and the lower mold of the mold are used at the part opposite to the one end of the plurality of leads. The lower mold clamps the lead frame so that a distance between the lower surface of the die pad and the inner side of the lower mold is smaller than the main surface of the semiconductor chip and the inner side of the lower mold in the thickness direction of the semiconductor chip. The distance between the inner sides of the upper mold, the mold has a gate on one side of the cavity of the mold for injecting molding material into the cavity; (e) injecting resin from the gate of the mold into the cavity of the mold by transfer molding, thereby sealing the semiconductor chip, the plurality of bonding wires, the A portion of the plurality of leads and the die pad. 36. The manufacturing method according to claim 35, wherein each of said support leads has an inner section and an outer section formed continuously with said inner section, and said upper mold and lower mold of said mold are used in step (d) The support leads are clamped at a boundary between the inner section and the outer section of each of the support leads, and the gate of the mold is located at one of the support leads. 37. The manufacturing method according to claim 36, wherein said resin is formed in a quadrangular shape, and said outer sections of said supporting leads protrude outward from four corners of said resin. 38. The manufacturing method according to claim 37, wherein said gate of said mold is located at one of four corners of said resin. 39. The manufacturing method according to claim 38, further comprising the step of cutting said support lead to separate said outer section of said support lead at said boundary after step (e). 40. The manufacturing method according to claim 35, wherein said back surface of said semiconductor chip is bonded to a surface of said die pad with an adhesive in said step (b). 41. The manufacturing method according to claim 40, wherein a part of said resin contacts said back surface of said semiconductor chip except a region bonded to said die pad. 42. The manufacturing method according to claim 40, wherein said die pad has a cross shape in plan view, and each of four strips defining said cross shape has a width wider than that of each of said supporting leads.

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