JP2006073570A - Semiconductor device and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-lead type semiconductor device having high connection reliability between a wire and a lead.
A non-lead type semiconductor device having a semiconductor chip located inside a sealing body, a lead exposing a lower surface of the bottom surface of the sealing body, and a wire connecting the electrode of the semiconductor chip and the lead in the sealing body. It is. The lead includes a narrow portion having a quadrangular cross section, a wide portion at a tip to which a wire having a width wider than the narrow portion is connected, and a tapered portion connecting the narrow portion and the wide portion. The wide portion has an inverted trapezoidal cross section having a processed surface that forms a predetermined angle with the upper surface on both sides of the upper surface, and the angle formed between the lower surface and the side surface of the inverted trapezoidal cross section is 110 °. Both side surfaces of the narrow portion have protrusions that are deformed and protruded laterally by partial crushing press processing of the upper surface of the narrow portion. At the tip of the lead, an overhang portion thinner than the lead formed by press molding is provided. The boundary portion between the narrow portion and the wide portion is thin over a predetermined length.
[Selection] Figure 1

Description

  The present invention relates to a resin-encapsulated semiconductor device using a lead frame formed by press molding or etching, and a manufacturing technology of an electronic device incorporating the semiconductor device, and more particularly, SON (Small Outline Non-Leaded Package), QFN. (Quad Flat Non-Leaded Package) and is effective when applied to the manufacture of semiconductor devices (non-lead type semiconductor devices) that are exposed on the mounting surface side without intentionally projecting external electrode terminals to the side of the package. Regarding technology.

A resin-encapsulated semiconductor device uses a lead frame in its manufacture. The lead frame is manufactured by forming a metal plate into a desired pattern by punching or etching with a precision press. The lead frame has a support portion called a tab, a die pad, or the like for fixing a semiconductor element (semiconductor chip), and a plurality of leads that make the tip (inner end) face the periphery of the support portion. The tab is supported by a tab suspension lead extending from the frame portion of the lead frame.
When manufacturing a resin-encapsulated semiconductor device using such a lead frame, the semiconductor chip is fixed to the tab of the lead frame, and the electrode of the semiconductor chip and the tip of the lead are connected by a conductive wire. Then, the inner end side of the lead including the wire and the semiconductor chip is sealed with an insulating resin (resin) to form a sealed body (package), and then the unnecessary lead frame portion is cut and removed and protrudes from the package. Cutting leads and tab suspension leads.

On the other hand, as one of the resin-encapsulated semiconductor devices manufactured using a lead frame, a single-sided mold is performed on one side of the lead frame to form a package, and the leads that are external electrode terminals are exposed on one side of the package A semiconductor device structure (non-lead type semiconductor device) in which leads are not intentionally protruded from the peripheral surface of a package is known. In this semiconductor device, SON that exposes leads on both side edges of one surface of the package and QFN that exposes leads on four sides of one surface of a rectangular package are known.
The non-lead type semiconductor device has a simple package structure in which the lower surface of the lead is exposed to the lower surface (mounting surface) of the package (sealing body) to serve as an external electrode terminal. More specifically, the lead having a quadrangular cross-sectional shape comes into contact with the sealing body on the upper surface and the side surface opposite to the mounting surface. Here, when the lead has a right-angled shape such as a rectangle or a square, the side surface is arranged perpendicularly from the mounting surface of the sealing body, and therefore, only the force sandwiched by the sealing body is applied to the lead. There is a high risk of falling out of the package. Therefore, in order to make it difficult for the lead to come out of the package, the cross section of the lead that enters the package, that is, the inner lead, is an inverted trapezoidal cross section. This inverted trapezoidal cross section is formed by etching or pressing (for example, Patent Document 1).

WO02-061835

  A metal lead frame used for manufacturing a non-lead type semiconductor device is formed by selectively punching a thin metal plate with a press or selectively removing it by etching to form a desired lead pattern. In the non-lead type semiconductor device, the lower surface of the lead is exposed on the lower surface of the sealing body, the outer end surface of the lead is exposed on the side surface of the sealing body, and the remaining surface is covered with the sealing body. Yes. For this reason, the lead has an inverted trapezoidal cross section so that the lead does not fall off from the sealing body so that the lead does not easily fall out of the sealing body.

  When the inverted trapezoidal cross section is formed by etching, the side surface of the lead becomes an etched surface, the side surface becomes uneven by etching, and the side surface becomes a rough surface instead of a mirror surface. Adhesiveness is better than leads formed by press molding.

  However, a lead frame manufactured by etching (hereinafter referred to as an etching lead frame) has a higher manufacturing cost than a lead frame formed by press molding (hereinafter referred to as a press lead frame).

  The present applicant has already proposed a manufacturing technique of a non-lead type semiconductor device manufactured by using a press lead frame in which a lead has an inverted trapezoidal cross section by press molding (WO 02-061835). In the proposed non-lead type semiconductor device, both sides of the upper surface of the lead portion having an inverted trapezoidal cross section are crushed and pressed to form a processed surface having a predetermined angle with the upper surface, and the lead width exposed from the lower surface of the sealing body As a result, the holding force of the lead by the resin forming the sealing body is increased. In the inverted trapezoidal cross section, both sides of the upper surface protrude in a triangular cross section, but as a result of forming this processed surface, the sharp part of the tip is crushed, resulting in a narrow lead width, and a width where resin between the leads exists. (Length) becomes longer, and the holding force of the lead by the resin increases. By using a lead having an inverted trapezoidal cross section having a processed surface, the lead can be made as thin as about 0.36 mm or 0.35 mm, compared with a case where the lead is not processed.

  In view of the demand for miniaturization of semiconductor devices, it is desired to reduce the lead pitch. By narrowing the lead pitch, the space between adjacent leads is narrowed, the amount of resin existing between the leads is reduced (resin width is shortened), the holding power of the leads by the resin is reduced, and the leads are removed from the sealed body. It becomes easy to come off. When the lead width is about 0.35 mm, it is difficult to set the lead pitch to 0.4 mm when considering the holding force of the lead by the resin.

  The non-lead type semiconductor device manufactured using the press lead frame already proposed by the present applicant is the reliability of the semiconductor device itself and the reliability in the substrate mounting temperature cycle test performed in a state where the semiconductor device is mounted on the mounting substrate. In this case, high reliability is ensured as compared with a non-lead type semiconductor device manufactured using a lead frame that is not pressed.

  On the other hand, since a semiconductor device is used in a more severe environment, it is also required to improve reliability in a state where it is incorporated in an electronic device. For example, in a mobile phone, after mounting an electronic component such as a semiconductor device on a mounting board, the mounting board is dropped and a drop test for inspecting reliability is performed. For example, a board is mounted on a semiconductor device mounted on the mounting board. An external force (stress) that is intentionally bent and bent is applied for a certain period of time, and then a mechanical strength test for inspecting the reliability of the semiconductor device is performed.

  Therefore, the present applicant repeated experiments and analyzes in order to increase the mounting strength and mounting reliability of the semiconductor device and further reduce the lead width. In experiments and analyses, there were some cases in which a wire breakage failure occurred in the sealed body even when the mechanical strength test was not recognized as defective in appearance. When examining the products that caused these disconnection defects, there was a problem in the connection part between the wire and the lead, and the stress was applied to the lead and the wire in the direction in which the lead was away from the wire. It was found that the wire was disconnected from the lead.

An object of the present invention is to provide a non-lead type semiconductor device having a high connection reliability between a wire and a lead, a manufacturing method thereof, and an electronic device incorporating the semiconductor device.
Another object of the present invention is to provide a non-lead type semiconductor device capable of reducing the lead pitch and a method for manufacturing the same.
Another object of the present invention is to provide a technique capable of improving the reliability of a semiconductor device.
The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  The following is a brief description of an outline of typical inventions disclosed in the present application.

(1) a sealing body made of an insulating resin, a tab sealed by the sealing body, a tab suspension lead exposed to the mounting surface of the sealing body and connected to the tab, and the sealing body A plurality of leads exposing one surface on the mounting surface; a semiconductor element located in the encapsulant and fixed to one surface of the tab via an adhesive; electrodes formed on the surface of the semiconductor element; and the leads And a conductive wire that electrically connects the
At least a part of the lead includes an upper surface covered with the sealing body, a lower surface facing the upper surface and exposed from the sealing body, and side surfaces respectively connecting the upper surface and both side edges of the lower surface. A semiconductor having an inverted trapezoidal cross section, and both side edges of the upper surface are provided with processing surfaces having one end connected to the upper surface, the other end connected to the side surface, and a different extending direction from the upper surface and the side surface. A device,
The wire connecting portion has the inverted trapezoidal cross section having the processed surface, the lead portion connected to the wire connecting portion has a quadrangular cross section, and both sides of the quadrilateral cross section are provided on the upper surface of the lead. It has the protrusion which deform | transformed and protruded to the side by partial crushing press work.

The angle formed between the lower surface and the side surface of the inverted trapezoidal cross section is 110 °. Further, the width of the lead portion having the quadrangular cross section is narrower than the width of the lead portion having the inverted trapezoidal cross section, and the boundary between the lead portion having the inverted trapezoidal cross section and the lead portion having the square cross section. The portion is a thin lead portion over a predetermined length compared to the other lead portions. In addition, the tip of the lead covered with the sealing body is provided with an overhang portion that is formed by crushing pressing and is thinner than the lead. Further, a groove or a recess is provided on the lower surface of the lead. The protrusions on both sides of the lead are deformed laterally when the lead upper surface layer portion is formed by, for example, crushing a groove (V groove) along the extending direction of the lead at the center of the upper surface of the lead. And formed as a result of overhanging.
Such a semiconductor device is manufactured by the following method.

(A) A lead frame made of metal having a plurality of leads, a tab having a semiconductor element fixing surface, a plurality of tab suspension leads connected to the tab, and a frame portion connecting the leads and the tab suspension leads is manufactured. And a process of
(B) mounting a semiconductor element on the semiconductor element fixing surface via an adhesive;
(C) electrically connecting the electrode of the semiconductor element and the lead via a wire; (d) sealing the semiconductor element, the wire, the lead and the tab suspension lead with an insulating resin; And forming the sealed body with the insulating resin such that the tab suspension lead and the back surface of the lead are exposed from the insulating resin;
(E) separating the lead and the tab suspension lead from the frame part,
In the production, the lead frame is formed by forming a pattern by a punching press process in which a metal plate is repeated a plurality of times, and then performing a crushing process on a predetermined part by a crushing press process. By means of a mold and an upper mold, at least a part of the lead of the lead frame includes an upper surface covered with the sealing body, a lower surface facing the upper surface and exposed from the sealing body, and both side edges of the upper surface and the lower surface. Formed in an inverted trapezoidal cross section composed of side surfaces that are connected to each other, and both side edges of the upper surface are connected to the upper surface at one end and connected to the side surface at the other end, and have different extending directions from the upper surface and the side surface. A method of manufacturing a semiconductor device formed on a surface,
In the manufacturing of the lead frame, a lead connecting portion is formed in the inverted trapezoidal cross section having the machining surface at the tip end of the lead having the tip facing the tab, and is connected to the wire connecting portion. Is formed into a quadrangular cross section, and the upper surface of the lead portion having the quadrangular cross section is partially crushed and pressed to form protrusions projecting on both side surfaces of the lead.

  In addition, an angle formed between the lower surface and the side surface of the inverted trapezoidal cross section is formed to be 110 °. Further, the width of the lead portion having the square cross section is narrower than the width of the lead portion having the reverse trapezoid cross section, and the lead portion having the reverse trapezoid cross section and the lead portion having the square cross section are formed. A thin lead portion is formed in the boundary portion over a predetermined length as compared with other portions. Further, the tip of the lead is crushed and pressed to form an overhang portion thinner than the lead. Further, a groove or a depression is formed on the lower surface of the lead. The protrusions on both side surfaces of the lead are formed, for example, when a groove (V groove) along the lead extending direction is crushed and formed in the center of the upper surface of the lead by pressing. In other words, the protrusion is formed by deforming the upper surface layer portion of the lead so as to project laterally by forming the V groove.

  The non-lead type semiconductor device manufactured in this way is incorporated into a desired electronic device by connecting the lead exposed on the lower surface of the sealing body to the land on the upper surface of the mounting substrate with a conductive adhesive.

The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.
According to the means of (1), (a) at least a part of the leads entering the sealed body has an inverted trapezoidal cross section having a processed surface, and therefore the distance between adjacent leads and leads due to the presence of the processed surface. Becomes wider and the strength (terminal strength) for holding the lead by the sealing resin increases. In addition, since the lead portion of the quadrangular cross section connected to the inverted trapezoidal cross section has protrusions protruding on both side surfaces of the quadrangular cross section, this protrusion bites into the resin forming the sealing body and prevents the lead from coming off. As a result, the holding force of the leads by the resin can be increased, and the mounting strength of the semiconductor device can be improved and the mounting reliability can be increased. Therefore, the reliability of the electronic device incorporating the semiconductor device according to the present invention is increased.

  (B) Since the angle formed between the lower surface and the side surface of the inverted trapezoidal cross section having the processed surface is 110, the lead width can be made narrower than in the case where the angle formed is 120 °. In other words, since the width of the intervening resin can be increased, the holding force of the lead by the resin can be increased.

  (C) Since the thin overhang at the tip of the lead covered by the sealing body is positioned such that the top and bottom surfaces, both side surfaces, and the tip surface bite into the resin forming the sealing body, the lead is sealed It is difficult for the lead to fall off, and the holding force of the lead by the resin increases.

  (D) Since a groove or a recess is provided on the lower surface of the lead, when the semiconductor device is mounted on the mounting substrate, a bonding material for bonding the land of the mounting substrate and the lead of the semiconductor device is in the groove or the recess. The mounting strength of the semiconductor device increases due to the increase in the bonding area.

  (E) Since the width of the lead portion having the quadrangular cross section is narrower than the width of the lead portion having the inverted trapezoidal cross section having the processed surface, between the lead portions having the quadrangular cross section in the adjacent leads. Spacing increases. Therefore, the strength of the resin between the leads having a quadrangular cross section increases, and as a result, the holding force of the lead by the resin increases.

  (F) The boundary portion between the lead portion having the inverted trapezoidal cross section having the machining surface that is the tip of the lead and the lead portion having the quadrangular cross section is a thin thin lead portion over a predetermined length compared to the other portions. Therefore, when stress acts on the lead tip portion, the thin lead portion acts as a buffer member (buffer member) that relaxes the stress and bends. For example, a wire is connected to a lead portion having an inverted trapezoidal cross section. Therefore, when a stress is applied in a direction in which the wire is separated from the lead, the thin lead portion is bent so as to relieve the stress, and disconnection of the wire from the lead can be suppressed. As a result, the connection reliability of the wires to the leads can be increased, and the mounting strength of the semiconductor device can be improved.

  (G) Holding a lead by a resin by forming the lead with a lead portion having a reverse trapezoidal cross section having a processed surface and a lead portion having a square cross section connected to the reverse trapezoidal cross section via a tapered portion. An increase in power can be achieved. In addition, by making the angle between the lower surface and the side surface of the inverted trapezoidal cross section steep as 110 °, the lead width can be narrowed, and an increase in the holding force of the resin by the resin can be achieved. Further, by providing a protrusion that bites into the resin on the side surface of the lead portion having a quadrangular cross section and an overhanging portion that bites into the resin at the tip of the lead, an increase in the holding force of the lead by the resin can be achieved. Further, since the resin enters the V-groove formed to form the protrusion, the adhesion between the resin and the lead is improved. Further, the groove formed by crushing press forming the thin lead portion can also increase the adhesion area with the resin. As a result, the mounting strength of the semiconductor device can be improved.

  (H) As described in (g) above, the retention of the lead by the resin can be increased, and by reducing the lead width by sharpening the side surface of the widest part of the lead (the lead part having the inverted trapezoidal cross section), A semiconductor device capable of further reducing the lead pitch can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all the drawings for explaining the embodiments of the invention, those having the same function are given the same reference numerals, and their repeated explanation is omitted.

  1 to 25 are diagrams relating to a semiconductor device according to a first embodiment of the present invention, particularly a non-lead type semiconductor device and a manufacturing method thereof. In the first embodiment, an example in which the present invention is applied to a QFN type semiconductor device in which leads and tab suspension leads are exposed on the mounting surface side of the back surface of a rectangular encapsulant (package) will be described.

  1 to 3 are views showing the external appearance and internal structure of a semiconductor device. 4 to 11 are views showing the appearance of the lead and the cross-sectional structure of each part. FIG. 12 is a diagram illustrating a mounted state of the semiconductor device, that is, a part of the electronic device. 13 to 25 are diagrams relating to a method for manufacturing a semiconductor device.

As shown in FIGS. 1 to 3, the QFN type semiconductor device 1 has a sealing body (package) 2 formed of an insulating resin made of a flat rectangular body (rectangular body). A semiconductor element (semiconductor chip: chip) 3 is embedded in the package 2. The semiconductor chip 3 is fixed to a tab surface (main surface) of a rectangular tab (support) 4 with an adhesive 5 (see FIG. 3).
As shown in FIG. 3, the back surface (lower surface 12) of the package 2 is a surface on the mounting side. As shown in FIG. 2, the mounting surface side of the package 2 has a structure in which one surface (mounting surface 14) of the tab suspension lead 6 and the lead 7 connected to the tab 4 is exposed.

As shown in FIG. 2, the four corners of the tab 4 are connected to a tab suspension lead 6 extending radially, and the tab suspension lead 6 is a member that supports the tab 4 in a lead frame state. The tab 4, the tab suspension lead 6 and the lead 7 are formed of the same metal material, that is, a lead frame formed by patterning a single metal plate (see FIGS. 14 and 15). For example, the lead frame is formed from a copper plate. Other metal plates such as 42 alloy may be used.
In the first embodiment, the tab suspension lead 6 is formed so as to be extruded in one step in the middle by extrusion molding in the direction opposite to the mounting surface (bending: bent portion 6a). This pushing direction is pushed out to the semiconductor element fixing surface side for fixing the semiconductor element of the tab 4. Therefore, the lower surface of the tab 4 is structured not to be exposed on the mounting surface of the package 2.
Further, around the tab 4, a plurality of leads 7 are disposed at predetermined intervals along each side of the rectangular package 2 so that the inner end (tip) thereof is close to the periphery of the tab 4. The outer ends of the tab suspension lead 6 and the lead 7 extend to the periphery of the package 2.

The package 2 is a flat quadrangular body, and the corner (corner) is chamfered to form a slope 10. One slope 10 is connected to a gate for injecting resin (resin) when the package 2 is formed, and the other three slopes 10 are connected to an air vent where air escapes when the package 2 is formed. It was a place that had been.
Further, the side surface of the package 2 is an inclined surface 11 so that the package 2 can be easily removed from the molding die. Therefore, as shown in FIG. 3, the upper surface 13 is smaller than the size of the lower surface 12 of the package 2. The outer end of the tab suspension lead 6 is exposed on the slope 10 of the package 2 (see FIG. 1).

As shown in FIGS. 1 and 3, the lead 7 and the tab suspension lead 6 slightly protrude outward from the rising edge 2 a of the package 2 on the surface of the lead 7 and the tab suspension lead 6 covered with the package 2. This is a result of cutting the lead 7 and the tab suspension lead 6 at the portion of the lead 7 and the tab suspension lead 6 that are removed from the package 2 when the lead 7 and the tab suspension lead 6 are cut. The projecting length from is 0.1 mm or less.
As shown in FIGS. 1 and 3, there are resin burrs 9 between the leads 7 and the leads 7 and between the leads 7 and the tab suspension leads 6. The resin burrs 9 are also cut by a die and a punch. Therefore, at the periphery of the package 2, the edge of the resin burr 9 and the outer ends of the leads 7 and the tab suspension leads 6 are linearly aligned without being uneven. The resin burr 9 is a resin portion outside the rising edge 2a, and has the same thickness as the lead 4 or a little thinner.

In the first embodiment, the resin burr 9 has a structure thinner than the thickness of the lead 7. This is because in a single-sided mold in transfer molding, a resin sheet is stretched between the upper and lower molds of the molding die, and molding is performed so that one surface of the lead frame is in contact with this sheet, so that the lead bites into the sheet. Therefore, the resin burr 9 between the leads is thin, and a slight step is generated between the back surface of the package and the leads and tabs (see FIG. 3). When a sheet is not used, the thickness of the resin burr 9 and the thickness of the lead 7 are the same or thicker depending on the degree of clearance.
Further, after one-side molding by transfer molding, a plating film 15 (see FIGS. 3 and 9) is formed on the surface of the lead 7 and the tab suspension lead 6, and therefore the lower surface 12 of the package 2 and the lead are further formed by the presence of the plating film 15. 7 and the step 4 become large. In FIG. 9, the dotted portions are regions where the plating film 15 is formed.

  As described above, in the structure in which the mounting surface 14 which is the lower surface of the lead 7 and the tab suspension lead 6 is offset, when the semiconductor device 1 is surface-mounted on a wiring board such as a mounting board, the solder wet region is specified. There is a feature that mounting is good.

On the other hand, as shown in FIG. 3, the semiconductor chip 3 is fixed to the surface (upper surface) of the tab 4 in the package 2 via an adhesive 5. For example, Ag paste is used as the adhesive 5.
As shown in FIGS. 2 and 3, the tab 4 has a quadrangular shape and is completely covered with the resin 16 forming the package 2. A groove 17 is provided on the lower surface of the tab 4. The groove 17 is formed by pressing. For example, as shown in FIG. 2, the grooves 17 are respectively provided along the sides of the rectangle on the lower surface of the tab 4.

The groove 17 is filled with resin (sealing resin) 16. The presence of the groove 17 increases the adhesion area (adhesion area) between the tab 4 and the biphenyl resin (resin 16) constituting the package 2. In addition, since the resin bites into the groove 17 of the tab 4, the tab 4 becomes difficult to peel off from the resin, and moisture hardly accumulates at the interface. As a result, the explosion damage caused by the thermal expansion of moisture between the tab 4 and the sealing resin 16 is less likely to occur due to the heat at the time of mounting the QFN.
On the upper surface of the semiconductor element 3, as shown in FIG. 1, electrodes 19 are provided along each side of the rectangle. The electrode 19 and the lead 7 whose tip is brought close to the periphery of the tab 4 are connected by a conductive wire 20.

  The semiconductor device 1 of the first embodiment is characterized by the structure of the lead 7 and the contact state (engagement state) between the lead 7 and the resin forming the sealing body 2. 4 to 11 are enlarged views showing each part of the lead 7 removed from the package 2. The engagement of the lead 7 with the resin 16 forming the sealing body 2 will be described with reference to these drawings and the method for manufacturing the semiconductor device of FIGS.

As shown in the flowchart of FIG. 13, the semiconductor device 1 according to the first embodiment includes lead frame formation (S01), chip bonding (S02), wire bonding (S03), sealing (mold: S04), and deflash (S05). ), Plating (S06), marking (S07), and cutting (S08).
First, a lead frame is manufactured. FIG. 14 is a schematic plan view showing the top surface of a lead frame 45 having a matrix configuration used when manufacturing the QFN type semiconductor device 1, and FIG. 15 is a bottom view showing the bottom surface. Here, the upper surface and the lower surface indicate a positional relationship in a state where the product (semiconductor device 1) is obtained. For example, the upper surface is the first surface and the lower surface is the second surface. Accordingly, FIG. 14 is a plan view showing the first surface, and FIG. 15 is a plan view showing the second surface.

As shown in FIG. 14, this lead frame 45 has unit lead patterns 46 arranged in 20 rows along the longitudinal (long side) direction and in four rows along the width (short side) direction. 80 semiconductor devices 1 can be manufactured. On both sides of the lead frame 45, guide holes 47a to 47c used for conveying and positioning the lead frame 45 are provided.
On the left side of each row, a runner is located at the time of transfer molding. Therefore, an ejector pin hole 48 through which the ejector pin can penetrate is provided in order to peel off the resin cured at the runner portion from the lead frame 45 by the ejection of the ejector pin. In addition, an ejector pin hole 49 through which the ejector pin can pass is provided in order to peel off the resin branched from the runner and cured at the gate portion flowing into the cavity from the lead frame 45 by the ejection of the ejector pin.

  16 is a diagram showing the lead pattern 46 on the first surface (upper surface) of the lead frame 45, and FIG. 17 is a diagram showing the lead pattern 46 on the second surface (lower surface) of the lead frame 45. Since the semiconductor device 1 shown in FIGS. 1 and 2 also includes a portion conceptually showing the semiconductor device according to the present invention, the number of leads is different from those shown in FIGS.

  As shown in FIGS. 16 and 17, the lead pattern 46 for manufacturing the single semiconductor device 1 has a frame portion 50 having a rectangular frame shape. The tab suspension lead 6 extends from the four corners of the frame portion 50 toward the center of the frame, and has a pattern for supporting the tab 4 at the center. The tab suspension lead 6 is extruded in one stage in the middle by extrusion molding in the direction opposite to the mounting surface (bending portion 6a). As a result, the semiconductor element fixing surface side of the tab 4 supported by the tab suspension lead 6 is a protruding surface in the upper surface direction of the lead frame 45. The groove 17 described above is formed on the second surface (lower surface) of the tab 4.

On the other hand, a plurality of leads 7 extend inward from the inside of each side of the frame portion 50, and the inner ends thereof are close to the outer peripheral edge of the rectangular tab 4. In FIG. 16 and FIG. 17, the reference numerals of the processed portions of the lead 7 are omitted. Each processed portion of the lead 7 will be described with reference to FIGS.
Such a lead frame 45 unwinds a thin metal plate, for example, a hoop material (copper plate) wound around a reel, intermittently moves the inside of the progressive press, and processes at each processing station of the progressive press. Manufactured by. In progressive press, the lead material part is sequentially press-molded to form a lead pattern, then Ag spot plating is applied to the place where the wire or semiconductor chip is connected (fixed), and then the tab suspension lead 6 is extruded and bent. The lead frame 45 shown in FIG. 14 and FIG. 15 is manufactured by processing and further cutting the hoop material into a predetermined length.

  FIG. 18 is a schematic view showing a part of a press die of a progressive press. The press die 51 of the progressive press is composed of a lower die 51a and an upper die 51b, and a hoop material (material) 52 is intermittently provided between the lower die 51a and the upper die 51b, for example, from left to right. Moved to. Each time the hoop material 52 stops, the lower mold 51a and the upper mold 51b are clamped, and predetermined pressing is performed. In the first embodiment, a copper plate having a thickness of 0.2 mm is used as the hoop material 52.

  Next, press working performed sequentially along the moving direction of the hoop material 52 will be described. FIG. 19 is a diagram showing a state of punching, which is one of press forming, and the shape of the lead 7 protruding from the frame portion 50 formed by punching. That is, punching is sequentially performed at a plurality of processing stations to form tabs and tab suspension leads as well as lead formation. In this punching process, as shown in FIG. 19A, a predetermined portion of the hoop material 52 is punched by pressing the hoop material 52 placed on the die 53a with the stripper 53b and lowering the punch 53c. By repeating this selective punching, a unit lead frame pattern is formed. FIG. 19B is a plan view showing a lead 7 portion formed by such punching. The lead 7 protruding like a cantilever from the inner edge of the frame portion 50 has a narrow narrow portion 25 whose root portion is provided over a certain length and a constant length at the tip (inner end). And a wide portion 26 having a wide width, and a tapered portion 27 in which the width connecting the narrow portion 25 and the wide portion 26 gradually changes.

  In the first embodiment, in order to increase the holding force of the lead 7 by the resin 16 that forms the sealing body 2 between the lead 7 and the lead 7, the width d of the narrow portion 25 is formed to be 0.20 mm and wide. The width r of the portion 26 is formed to 0.26 mm. The narrow portion 25 has a length of about 0.25 mm, the wide portion 26 has a length of about 0.27 mm, and the tapered portion 27 has a length of about 0.08 mm.

  As shown in FIG. 20, a crushing press process is performed on the tapered portion 27 of the straight lead 7 having a wide tip as shown in FIG. As shown in FIG. 20, grooves 7 are formed on the upper surface of the lead 7 by coining the lead 7 placed on the die 60a having a flat upper surface by lowering the punch 60c having the inverted trapezoidal protrusion 60b on the lower surface. 21 is formed. The groove 21 is formed in the tapered portion 27 so as to cross the lead 7 (see FIGS. 4 and 10). The groove 21 is connected to the upper surface of the wide portion 26 of the lead 7 (upper surface serving as a wire connecting portion), and a first surface serving as one side surface of the groove 21 and a second surface serving as the groove bottom surface connected to the first surface. And a third surface which is connected to the second surface and the upper surface of the narrow portion 25 of the lead 7 and which is the other side surface of the groove 21. The second surface is flat and substantially parallel to the lower surface of the lead 7. The lead portion on the second surface becomes a thin lead portion that is thinner than other lead portions, and when a stress is applied to the leading end side of the lead, it becomes a thin buffer portion that can be bent to relieve the stress. ing. Since the thickness of the lead 7 is 0.2 mm, the depth of the groove 21 is, for example, 0.1 mm, and the buffer member has a thickness of 0.1 mm. The angle formed by the first surface and the second surface is 90 ° or more. This is for avoiding improvement in workability and stress concentration during press working. The depth of the groove | channel 21 is not limited to the said depth, About 50 micrometers-about 0.1 mm are selected. The length of the thin lead portion is selected to be about 0.1 mm to 0.25 mm. Since the V-groove dislikes breakage of the lead 7 due to stress concentration, the above-described inverted trapezoidal cross-section groove is adopted as the groove 21.

  In the progressive press, V-groove processing is performed in which the cross-section becomes a V-groove. This V-groove processing is the formation of the groove 17 on the lower surface of the tab 4 described above (see FIG. 17). As shown in FIGS. 8 and 11, the taper portion 27 is formed from the middle portion of the wide portion 26 on the lower surface of the lead 7. This is the formation of the groove 70 in a portion extending over the narrowing portion 25. Further, as shown in FIGS. 4 and 11, V-groove processing is also performed in the longitudinal direction from the groove 21 provided in the taper portion 27 of the lead 7 to the middle of the narrow portion 25 to form a groove (protrusion forming groove). ) 71 is formed. The protuberance forming groove 71 is formed along the center of the upper surface of the lead 7 and is formed deeper and wider than the groove 70. While the width of the groove 70 is 0.05 mm, the width of the protrusion-forming groove 71 is 0.1 mm. In addition, the depth of the groove 70 is 0.03 mm, whereas the depth of the protrusion forming groove 71 is 0.08 mm.

  The formation of the groove 70 on the lower surface of the lead 7 and the formation of the groove 17 on the lower surface of the tab 4 are performed by crushing pressing shown in FIGS. 21 (a) and 21 (b). FIG. 21A shows a die for forming a V-groove on the lower surface of a tab or lead. For example, the lead 7 is placed on a die 62a having a protrusion 62b having an inverted V-shaped cross section, and the lower surface is a flat punch. A groove 70 is formed on the lower surface of the lead 7 by lowering 62c. By using the die 62a in which the protrusions 62b are discontinuously arranged in a rectangular frame shape, the grooves 17 that are discontinuously connected in the rectangular frame shape as shown in FIG. 17 can be formed. Since the groove 70 has a narrow groove width and is shallow, as shown in FIG. 7, the width d of the narrow portion 25 having a quadrangular cross section does not change and is 0.20 mm, which is the same as the width f of the upper surface. maintain.

  FIG. 21B shows a mold for forming a deep and wide groove (projection forming groove) 71 at the center of the upper surface of the lead 7. The lead 7 is placed on a die 63 a having a flat upper surface, and V is formed on the lower surface. A groove 63 having a V-shaped cross section is formed on the upper surface of the lead 7 by lowering a punch 63 c having a protrusion 63 b having a V-shaped cross section. When the groove 71 is formed, the surface layer portion on the upper surface of the narrow portion 25 is deformed so as to be pushed out to both sides by the pressing force, and the protrusion 72 whose upper surface side protrudes most is formed. The protrusion 72 is formed along a groove (protrusion forming groove) 71. The protrusion 72 is formed by a protrusion 63b having a V-shaped cross section on the upper surface of the narrow narrow portion 25 having a width of 0.20 mm, a large protrusion having a groove width of 0.8 mm and a groove depth of 0.15 mm. By forming the portion forming groove 71, the surface layer portion of the upper surface of the lead 7 is deformed. By pressing the center of the narrow portion 25 with the protrusion 63b, the protrusion 72 protrudes on both sides of the narrow portion 25 with the same protrusion length.

  Since this protrusion 72 is formed, as shown in FIG. 6, the width e of the upper surface of the narrow portion 25 having a quadrangular cross section increases from 0.20 to 0.24. If the protrusions 72 protrude evenly on both sides of the protrusion forming groove 71, the protrusion length of the protrusion 72 is 0.02 mm. This portion bites into (engages with) the resin 16 forming the sealing body 2, and the holding force of the lead by the resin 16 is increased.

  In the progressive press, a press molding process is performed in which the tip portion of the lead 7 is formed into an inverted trapezoidal cross section having a processed surface. The formation of the inverted trapezoidal cross section having the processed surface is formed by forming the inverted trapezoidal cross section shown in FIG. 22A and the processed surface forming shown in FIG. First, as shown in FIG. 22A, the wide portion 26 which is the tip portion of the lead 7 in the groove 65b of the die 65a having the groove 65b having an inverted trapezoidal cross section (may be a V-shaped cross section) on the upper surface. Position and insert. Thereafter, the punch 65c whose lower surface is a flat surface is lowered and the lead 7 is crushed and pressed. By this crushing press processing, the lead 7 having a rectangular cross section indicated by a one-dot chain line in FIG. 22A is deformed so as to correspond to the groove 65b in the process of being pushed down by the punch 65c to form the inclined side surface 74. As shown, it has an inverted trapezoidal cross section. At this time, the unpressurized portions on both sides of the upper surface of the lead 7 are swelled curved surfaces. The angle formed between the side surface 74 and the lower surface of the lead 7 is a steep surface of about 110 ° instead of the conventional 120 °. As a result, the width of the wide portion 26 of the lead 7 can be reduced. The angle formed between the side surface 74 and the lower surface of the lead 7 may be about 100 ° to 120 °. However, if the angle formed is too close to 90 °, the difference between the width of the lower surface of the lead 7 and the width of the upper surface becomes small, the length that the lead 7 bites into the resin 16 becomes small, and the lead 7 Is easy to come off.

  Next, as shown in FIG. 22B, the wide portion 26 of the lead 7 having an inverted trapezoidal cross section is placed on a die 66a that is a flat surface. Thereafter, the punch 66c having the trapezoidal cross-section groove 66b on the lower surface is lowered to press and flatten the curved surface portions on both sides of the upper surface of the wide portion 26 having the inverted trapezoidal cross section on both side surfaces of the trapezoidal cross section. 75 is formed. An angle formed by the processed surface 75 and the upper surface of the lead 7 is, for example, 120 °. The processing surfaces 75 on both sides of the upper surface of the inverted trapezoidal cross section are symmetric with respect to the center line of the inverted trapezoidal cross section. However, the present invention is not limited to this symmetrical structure, and one protruding length may be longer than the other protruding length.

  As shown in FIG. 5, the wide portion 26 of the lead 7 is formed in an inverted trapezoidal cross section having a processed surface 75 by crushing press processing twice. This lead portion has a lower surface width c of 0.18 mm, an upper surface width b of 0.26 mm, a side tip end width a formed by the side surface 74 and the processed surface 75 of 0.3 mm, and a thickness of 0.2 mm. . Since this type of conventional lead has a width of 0.36 mm or 0.35 mm, in the case of the semiconductor device 1 according to the first embodiment, the width of the lead 7 can be reduced by 0.06 mm to 0.05. The interval between adjacent leads is widened, and the holding force of the leads by the resin forming the sealing body can be increased.

  In the progressive press, a press forming process is performed in which a protruding portion thinner than the lead is formed at the tip portion of the lead 7. As shown in FIG. 23A, the lead 7 is placed on a die 67a having a flat upper surface, and the lead 7 is held between the die 67a by a clamper 67b lowered. Then, as shown in FIG. 23 (b), the punch 67c is raised from below, the tip of the lead 7 is pushed up to a midway height and crushed and pressed (coining). A protruding portion 76 is formed. As a result of the overhanging portion 76 being covered with the resin 16 that forms the sealing body 2 at the top and bottom surfaces, the left and right side surfaces, and the front end surface, the leads 7 are difficult to come off from the bottom surface of the sealing body 2. The presence of the overhanging portion 76 further increases the holding force of the lead by the resin. The crushing depth of the tip of the lead 7 for forming the overhang portion 76 is 50 μm to 0.1 mm, and the crushing length is 0.1 mm to 0.2 mm. Since the portion that has been crushed and deformed by this crushing pressing process further protrudes toward the tip of the lead, the protruding length of the overhanging portion 76 is slightly longer than the crushing length.

The lead pattern 46 as shown in FIGS. 16 and 17 is formed by the series of press forming processes described above.
Next, although not shown, Ag spot plating is performed to form the plating film 22. This spot plating is performed on the semiconductor element fixing surface of the tab 4 for fixing the semiconductor element and the wire bonding region of the lead 7 connecting the wire (see FIGS. 3 and 24).

  Next, although not shown, cutting (including bending) is performed. In this step, tabs are raised by bending (extrusion pressing). In this extrusion press processing, a portion including the tab 4 and continuing to the tab 4 is formed by pressing the punch downward while the upper surface (first surface) of the lead frame used during assembly is the lower surface. Thereafter, the hoop material (material) 52 is cut into predetermined lengths.

A lead frame 45 as shown in FIGS. 14 and 15 is manufactured by a series of press forming processes by the above-described progressive press (lead frame formation: S01).
When manufacturing the semiconductor device 1 using such a lead frame 45, as shown in FIG. 24, the semiconductor chip 3 is fixed to the upper surface of the tab 4 using an adhesive 5 such as Ag paste (chip bonding: S02). ). The adhesive 5 is baked at a predetermined temperature for a predetermined time and cured.

  Next, as shown in FIG. 24, the electrode 19 (see FIG. 1) not shown in FIG. 24 provided on the upper surface of the semiconductor chip 3, and the lead 7 portion (wide portion) at the tip of the lead 7 from the groove 21. 26) is electrically connected by a conductive wire 20 (wire bonding: S03). The wire 20 is connected on the plating film 22. Since the plating film 22 made of Ag plating is provided in the wire connection region, the connection strength of the wire is high.

  Next, single-sided molding is performed on a predetermined region of the lead frame 45 by ordinary transfer molding, and a sealing body (package) 2 made of an insulating resin is formed as shown in FIG. 25 (sealing: S04). The tab 4, the semiconductor chip 3, and the wire 20 are completely covered with the package 2. The lower surface of the lead 7 is exposed from the lower surface 12 of the package 2. Although not shown, the lower surface of a part of the tab suspension lead 6 is exposed from the lower surface 12 of the package 2. During this transfer molding, a sheet is placed on the lower surface side of the lead frame, and sealing is performed so that the package 2 is formed on the upper surface side of the lead frame. As a result, the lower surface 12 of the package 2 is retracted from the mounting surface 14 which is the lower surface of the lead 7.

Next, in the sealing, since the resin component of the sealing resin 16 constituting the package 2 may adhere to the exposed surface of the lead 7, this resin component is removed (deflash: S05). This deflashing is performed, for example, by spraying water on the surface of the lead 7 exposed from the lower surface 12 of the package 2 under high pressure.
Next, the plating film 15 is formed on the surface of the lead 7 in the state of the lead frame (S06). The plating film 15 is made of, for example, PbSn solder (see FIG. 9).
Next, although not shown, a predetermined mark is marked on the upper surface of the package 2 (S07).

  Next, the lead 7, the tab suspension lead 6 and the sealing resin 16 (resin burr 9) existing between the leads 7 or between the lead 7 and the tab suspension lead 6 are cut along the outer periphery of the package 2 to remove unnecessary leads. The frame portion is removed, and the semiconductor device 1 as shown in FIGS. 1 to 3 is manufactured (S08). In this case, the punch is operated from the lower surface side to the upper surface side of the lead frame 45 to perform cutting. Therefore, the outer edge of the lead 7 exposed on the lower surface 12 of the package 2 of the semiconductor device 1 is rounded on the lower surface, and there is no inconvenience due to the cutting edge during mounting.

By mounting such a semiconductor device 1 on a mounting substrate, the electronic device shown in FIG. 12 is manufactured. In the manufacture of the electronic device, first, a mounting substrate (wiring substrate) 40 having electrodes (lands) 41 is prepared at positions facing each of the leads 7 exposed on the mounting surface side of the sealing body 2 of the semiconductor device 1. Thereafter, the land 41 on the mounting substrate 40 and the plurality of leads 7 are opposed to each other, and heat treatment (reflow) is performed. The lower surface of the lead 7 is covered with a plating film 15, and since the plating film 15 is made of PbSn solder, the solder is melted by reflow, and the melted solder forms a bonding material 42 to form the bonding material 42 and the land 7. 41 will be connected.
The first embodiment has the following effects.

  (1) Since at least a part of the lead 7 entering the sealing body 2 has an inverted trapezoidal cross section having a processed surface 75, the presence of the processed surface 75 increases the distance between adjacent leads 7 and leads 7. The strength (terminal strength) for holding the lead 7 by the sealing resin 16 is increased. Further, since the lead portion of the quadrangular cross section that is connected to the inverted trapezoidal cross section has the protrusions 72 that protrude from both sides of the quadrangular cross section, the protrusion 72 bites into the resin 16 that forms the sealing body 2. The lead 7 can be prevented from coming off, the holding force of the lead 7 by the resin 16 can be increased, and the mounting strength and mounting reliability of the semiconductor device 1 can be improved. Therefore, the reliability of the electronic device incorporating the semiconductor device 1 according to the present invention is increased. As a result, by manufacturing the semiconductor device to be incorporated into the mobile phone by the manufacturing method of the first embodiment, a mobile phone with high mounting reliability can be manufactured.

  (2) Since the angle formed by the lower surface (mounting surface 14) of the inverted trapezoidal cross section having the processed surface 75 and the side surface 74 is 110 °, the lead width is made narrower than when the angle formed is 120 °. Since the resin amount between the adjacent leads 7 can be increased, in other words, the width of the intervening resin can be increased, the holding force of the leads 7 by the resin 16 can be increased.

  (3) Since the thin protruding portion 76 at the tip of the lead 7 covered with the sealing body 2 bites into the resin 16 forming the sealing body, the lead 7 seals the top and bottom surfaces, both side surfaces, and the tip surface. It becomes difficult to drop off from the body 2, and the holding force of the lead 7 by the resin 16 increases.

  (4) Since the groove 70 is provided on the lower surface of the lead 7, the bonding material 42 that bonds the land 41 of the mounting substrate 40 and the lead 7 of the semiconductor device 1 when the semiconductor device 1 is mounted on the mounting substrate 40. Enters into the groove 70, and the mounting strength of the semiconductor device 1 increases due to an increase in the bonding area. Note that even if a recess is provided in place of or in addition to the groove 70, the mounting strength of the semiconductor device 1 can be increased for the same purpose as described above.

  (5) Since the width of the lead portion (narrow portion 25) having a quadrangular cross section is narrower than the width of the lead portion (wide portion 26) having an inverted trapezoidal cross section having the processed surface 75, it is adjacent. In the lead 7, the interval between the lead portions (narrow portions 25) having a quadrangular cross section is widened. Accordingly, the strength of the resin 16 between the narrow portions 25 increases, and the holding force of the leads 7 by the resin 16 increases.

  (6) A boundary portion (tapered portion 27) between a lead portion (wide portion 26) having an inverted trapezoidal cross section having a processed surface 75 which is the tip of the lead 7 and a lead portion (narrow portion 25) having a square cross section is predetermined. Since the thin lead portion is thinner than the lead 7 over the entire length, when stress acts on the tip end portion of the lead, the thin lead portion acts as a buffer member (buffer member) that relaxes the stress and bends. For example, the wire 20 is connected to a lead portion (wide portion 26) having an inverted trapezoidal cross section. Therefore, when a stress is applied in a direction in which the wire 20 moves away from the lead 7, the thin lead portion is bent so as to relieve the stress, and disconnection of the wire 20 from the lead 7 can be suppressed. As a result, the connection reliability of the wire 20 to the lead 7 can be improved, and the mounting strength of the semiconductor device 1 can be improved.

  (7) A lead portion (wide portion 26) having an inverted trapezoidal cross section with the processed surface 75 of the lead 7, and a lead portion (narrow portion 25) having a quadrangular cross section connected to the wide portion 26 via a taper portion 27. By configuring the lead 7 in this manner, the holding force of the lead 7 by the resin 16 can be increased. Further, by making the angle formed by the lower surface of the inverted trapezoidal cross section and the side surface 74 as steep as 110 °, the lead width can be reduced, and the holding force of the lead 7 by the resin 16 can be increased. Further, the protrusion 72 that bites into the resin is provided on the side surface of the lead portion having the quadrangular cross section, and the overhanging portion 76 that bites into the resin is provided at the tip of the lead, thereby increasing the holding force of the lead 7 by the resin 16. Further, since the resin 16 enters the protrusion forming groove 71 formed to form the protrusion 72, the adhesiveness between the resin 16 and the lead 7 is improved. Further, the groove 21 formed by crushing press forming the thin lead portion can also increase the adhesion area with the resin 16. As a result, the mounting strength of the semiconductor device 1 can be improved.

  (8) As described in (7) above, the holding force of the lead 7 by the resin 16 can be increased, and the side surface 74 of the widest portion of the lead 7 (the lead portion having the inverted trapezoidal cross section: the wide portion 26) is sharpened. The semiconductor device 1 that can further reduce the lead pitch can be provided by reducing the lead width.

  For example, when the lead frame 45 is manufactured, at the stage where the lead pattern 46 is formed by punching a metal plate having a constant thickness (0.2 mm), the lead portion has a wide end portion 26 having a wide width and a narrow width portion. The narrow portion 25 and a tapered portion 27 in which the width connecting the narrow portion 25 and the wide portion 26 gradually changes. The wide portion 26 has a square cross section with a width of 0.26 mm and a height of 0.2 mm, and the narrow portion 25 has a square cross section with a width of 0.20 mm and a height of 0.2 mm. The wide portion 26 has an inverted trapezoidal cross section having a processed surface 75 by pressing. The width of the lower surface of the inverted trapezoidal cross section is 0.18 mm, the width of the upper surface is 0.26 mm, and an overhang formed by the processed surface 75 and the side surface 74. The width between the parts is 0.3 mm. In addition, although the narrow portion 25 is partially formed with a protrusion 72 on the upper surface side, the width of the lower surface of the narrow portion 25 that becomes the mounting surface 14 is maintained at 0.20 mm.

  By adopting such a lead cross-sectional structure, the mounting width of the lead 7 is set to 0.18 mm in a partly short range, but the lead pitch maintaining the 0.2 mm width as a whole is 0.4 mm. Thus, the non-lead type semiconductor device 1 can be manufactured. In this semiconductor device 1, even if the pitch of the leads 7 is 0.4 mm, the width of the mounting surface of the leads 7 is maintained at 0.2 mm, and the action of each part including the protrusion 72 as described above. Since the holding force of the leads 7 by the resin 16 can be increased, the non-lead type semiconductor device 1 having sufficient mounting strength is obtained.

  FIG. 26 is a front view in which a part of the non-leaded semiconductor device according to the second embodiment of the present invention is cut away. In the second embodiment, the semiconductor device 1 is manufactured using a flat lead frame in which the tab suspension lead 6 is not bent. As a result, the lower surface 80 of the tab 4 is exposed from the mounting surface 12 which is the lower surface of the package 2. This structure has a feature that the height of the package 2 can be reduced and heat generated in the semiconductor chip 3 can be quickly released to the mounting substrate via the tab 4.

27 to 31 are diagrams relating to a non-lead type semiconductor device which is Embodiment 3 of the present invention. 27 is a plan view showing the upper surface of the lead of the semiconductor device, FIG. 28 is a bottom view showing the lower surface of the lead of the semiconductor device, FIG. 29 is an enlarged sectional view taken along the line AA in FIG. FIG. 31 is an enlarged sectional view taken along the line CC of FIG. 27. FIG.
The lead 7 of the semiconductor device 1 according to the third embodiment has the same structure as the lead 7 of the semiconductor device 1 according to the first embodiment except that the formation structure of the protrusion 81 provided in the narrow portion 25 is different. In the case of Example 1, the protrusion 72 that protrudes on both sides of the upper surface of the narrow portion 25 is formed with a protrusion forming groove 71 in the longitudinal direction on the upper surface of the lead 7 by press molding at the center of the upper surface of the narrow portion 25. In the case of the third embodiment, as shown in FIG. 27 and FIG. 30, the narrow portion 25 is formed by crushing the side edge portion of the upper surface of the narrow portion 25 (lead 7) and crushing each by pressing to form the recess 82. A protrusion 81 is formed on the side surface on the upper surface side. Although not shown in the drawing, a portion including side edges on both sides of the upper surface of the narrow portion 25 is crushed by press molding to form a recess 82. When the recess 82 is formed, the side surface is in a free state, so that the protrusion 81 is formed by being pushed out and projecting to the side.

Since the protrusion 81 bites into (engages with) the resin 16 forming the sealing body 2, the lead 7 is prevented from falling off from the sealing body 2. Therefore, the semiconductor device 1 of the third embodiment is also a semiconductor device having high mounting strength and high mounting reliability.
The invention made by the present inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Nor.
In the above embodiment, the example in which the present invention is applied to the manufacture of a QFN type semiconductor device has been described. However, for example, the present invention can be similarly applied to the manufacture of a SON type semiconductor device and has the same effect. Can do.
In addition, the present invention can be applied not only to the crushing process in the press lead frame but also to the crushing process of the present invention for the one in which the lead pattern is formed by etching (etching lead frame). That is, after forming a lead pattern by etching the metal plate, the crushing forming process according to the present invention is performed on each lead portion to form the protrusion 72 by forming the groove 21 and the protrusion-forming groove 71. Any one or all of the formation of the groove 70, the formation of the overhang 76, the formation of the side surface 74, and the formation of the processed surface 75 are performed. This makes it possible to increase the holding force of the lead by the resin and to narrow the lead pitch.

1 is a plan view in which a part of a non-leaded semiconductor device that is Embodiment 1 of the present invention is cut away; FIG. It is the bottom view which notched a part of the non-lead type semiconductor device. It is the front view which notched a part of the non-lead type semiconductor device. It is a top view which shows the lead | read | reed in the said non-lead-type semiconductor device. It is an expanded sectional view which follows the AA line of FIG. It is an expanded sectional view which follows the BB line of FIG. It is an expanded sectional view which follows the CC line of FIG. It is a bottom view which shows the lower surface (bottom surface) of the lead | read | reed in the said non-lead-type semiconductor device. In the non-lead type semiconductor device, it is a bottom view showing a lead portion exposed on the lower surface of the sealing body. It is a side view showing a lead in the non-lead type semiconductor device. It is sectional drawing which follows the DD line | wire of FIG. FIG. 3 is a schematic cross-sectional view showing a part of an electronic device on which the non-leaded semiconductor device of Example 1 is mounted. 3 is a flowchart showing manufacturing steps of the non-leaded semiconductor device according to the first embodiment. 3 is a plan view showing the top surface of a lead frame used in the manufacture of the non-leaded semiconductor device of Example 1. FIG. 6 is a bottom view showing a lower surface of a lead frame used in manufacturing the non-leaded semiconductor device according to the first embodiment. FIG. It is a top view which shows the upper surface of the lead pattern of the said lead frame. It is a bottom view which shows the lower surface of the lead pattern of the said lead frame. It is a schematic diagram which shows the progressive press which manufactures the said lead frame. It is a top view which shows the lead part before the crushing press process formed by the lead stamping by the said progressive press. It is a schematic diagram which shows the metal mold | die and lead which form the thin lead part in the said progressive press. It is a schematic diagram which shows the metal mold | die and lead which form the V groove in the said progressive press. It is a schematic diagram which shows the metal mold | die and lead which form the inverted trapezoid cross section in the said progressive press. It is a schematic diagram which shows the metal mold | die and lead which form the overhang | projection part in the said progressive press. FIG. 4 is an enlarged cross-sectional view of a part of the lead frame showing a state in which a semiconductor chip is mounted on the main surface of the tab and wire bonding is performed in the manufacture of the non-leaded semiconductor device according to the first embodiment. FIG. 3 is an enlarged cross-sectional view of a part of the lead frame in a state where resin sealing is performed in the manufacture of the non-leaded semiconductor device according to the first embodiment. It is the front view which notched a part of non lead type semiconductor device which is Example 2 of the present invention. It is a top view which shows the upper surface of the lead | read | reed in the non-lead-type semiconductor device which is Example 3 of this invention. It is a bottom view showing the lower surface of the lead in the non-leaded semiconductor device of the third embodiment. It is an expanded sectional view which follows the AA line of FIG. It is an expanded sectional view which follows the BB line of FIG. It is an expanded sectional view which follows the CC line of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Semiconductor device, 2 ... Sealing body (package), 2a ... Rising edge, 3 ... Semiconductor chip, 4 ... Tab, 5 ... Adhesive, 6 ... Tab suspension lead, 6a ... Bending part, 7 ... Lead, 9 ... Resin burr, 10 ... slope, 11 ... slope, 12 ... bottom surface, 13 ... top surface, 14 ... mounting surface, 15 ... plating film, 16 ... resin, 17 ... groove, 19 ... electrode, 20 ... wire, 21 ... groove, 22 DESCRIPTION OF SYMBOLS ... Plating film, 25 ... Narrow part, 26 ... Wide part, 27 ... Tapered part, 40 ... Mounting board (wiring board), 41 ... Electrode (land), 42 ... Bonding material, 45 ... Lead frame, 46 ... Lead pattern, 47a to 47c ... guide hole, 48,49 ... ejector pin hole, 50 ... frame portion, 51 ... press die, 51a ... lower die, 51b ... upper die, 52 ... hoop material (material), 53a ... die, 53b ... Stripper, 53c ... Punch, 60a Die, 60b ... inverted trapezoidal protrusion, 60c ... punch, 62a ... die, 62b ... protrusion, 62c ... punch, 63a ... die, 63b ... protrusion, 63c ... punch, 65a ... die, 65b ... groove, 65c ... Punch, 66a ... Die, 66b ... Trapezoidal cross-section groove, 66c ... Punch, 67a ... Die, 67b ... Clamper, 67c ... Punch, 70 ... Groove, 71 ... Groove (projection forming groove), 72 ... Projection , 74 ... side surface, 75 ... processed surface, 76 ... overhang, 80 ... lower surface, 81 ... projection, 82 ... depression.

Claims (24)

A sealing body made of an insulating resin;
A tab sealed to the sealing body;
A tab suspension lead exposed on the mounting surface of the sealing body and connected to the tab;
A plurality of leads exposing one surface on the mounting surface of the sealing body;
A semiconductor element located in the sealing body and fixed to one surface of the tab via an adhesive;
An electrode formed on the surface of the semiconductor element and a conductive wire that electrically connects the lead;
At least a part of the lead includes an upper surface covered with the sealing body, a lower surface facing the upper surface and exposed from the sealing body, and side surfaces respectively connecting the upper surface and both side edges of the lower surface. Inverted trapezoidal cross section
And on both side edges of the upper surface, one end is connected to the upper surface, the other end is connected to the side surface, and the upper surface and the side surface are provided with processed surfaces having different extending directions,
The portion connecting the wires becomes the inverted trapezoidal cross section having the machining surface,
The lead portion connected to the wire connecting portion has a rectangular cross section,
In addition, the semiconductor device according to claim 1, wherein protrusions projecting laterally by a partial crushing press process of the upper surface of the lead are provided on both side surfaces of the rectangular cross section. The protrusions on both side surfaces of the lead are formed by deforming and projecting sideways when crushing in the longitudinal direction on the upper surface of the lead and forming a groove by press working. A semiconductor device according to 1. The protrusions on both side surfaces of the lead are formed by deforming and projecting sideways when a recess is formed by crushing a portion including a side edge of the upper surface of the lead. The semiconductor device according to claim 1. Compared to the width of the lead portion that is the inverted trapezoidal cross section, the width of the lead portion that is the square cross section is narrow,
A boundary portion between the lead portion having the inverted trapezoidal cross section and the lead portion having the quadrangular cross section is a thin lead portion that is thinner than other lead portions over a predetermined length. The semiconductor device according to claim 1. In the boundary portion, the first surface continuous to the upper surface of the lead of the portion connecting the wire, the second surface continuous to the first surface, the lead connected to the portion connecting to the second surface and the second surface. 5. A groove that crosses the lead is provided by a third surface that is continuous with the upper surface of the lead of the portion, and the lead portion on which the second surface exists forms the thin lead portion. A semiconductor device according to 1. The semiconductor device according to claim 1, wherein an angle formed between a lower surface and a side surface of the inverted trapezoidal cross section is 100 ° to 120 °. 2. The semiconductor device according to claim 1, wherein a tip of the lead covered with the sealing body is provided with an overhanging portion formed by crushing press processing and thinner than the lead. The semiconductor device according to claim 1, wherein a width dimension of a lower surface of the lead is equal to or less than a resin width dimension between adjacent leads. The semiconductor device according to claim 1, wherein a groove or a recess is provided on a lower surface of the lead. A sealing body made of an insulating resin;
A tab sealed to the sealing body;
A tab suspension lead exposed on the mounting surface of the sealing body and connected to the tab;
A plurality of leads exposing one surface on the mounting surface of the sealing body;
A semiconductor element located in the sealing body and fixed to one surface of the tab via an adhesive;
An electrode formed on the surface of the semiconductor element and a conductive wire that electrically connects the lead;
At least a part of the lead includes an upper surface covered with the sealing body, a lower surface facing the upper surface and exposed from the sealing body, and side surfaces respectively connecting the upper surface and both side edges of the lower surface. A semiconductor device having an inverted trapezoidal cross section,
A boundary portion between the lead connecting portion of the lead and the lead connecting portion connecting the wire is a thin lead portion that is thinner than other lead portions over a predetermined length. A semiconductor device. In the boundary portion, the first surface continuous to the upper surface of the lead of the portion connecting the wire, the second surface continuous to the first surface, the lead connected to the portion connecting to the second surface and the second surface. A groove that crosses the lead is provided by a third surface that is continuous with the upper surface of the lead of the portion, and the lead portion where the second surface exists forms the thin lead portion;
The angle formed by the second surface and the first surface is 90 ° or more, and the angle formed by the second surface and the third surface is 90 ° or more. The semiconductor device according to claim 10. (A) A lead frame made of metal having a plurality of leads, a tab having a semiconductor element fixing surface, a plurality of tab suspension leads connected to the tab, and a frame portion connecting the leads and the tab suspension leads is manufactured. And a process of
(B) mounting a semiconductor element on the semiconductor element fixing surface via an adhesive;
(C) electrically connecting the electrode of the semiconductor element and the lead via a wire;
(D) sealing the semiconductor element, the wire, the lead and the tab suspension lead with an insulating resin, and the insulating resin such that the tab suspension lead and the back surface of the lead are exposed from the insulating resin; Forming a sealed body by:
(E) separating the lead and the tab suspension lead from the frame part,
In the production, the lead frame is formed by forming a pattern by a punching press process in which a metal plate is repeated a plurality of times, and then performing a crushing process on a predetermined part by a crushing press process. By means of a mold and an upper mold, at least a part of the lead of the lead frame includes an upper surface covered with the sealing body, a lower surface facing the upper surface and exposed from the sealing body, and both side edges of the upper surface and the lower surface. Formed in an inverted trapezoidal cross section composed of side surfaces that are connected to each other, and both side edges of the upper surface are connected to the upper surface at one end and connected to the side surface at the other end, and have different extending directions from the upper surface and the side surface. A method of manufacturing a semiconductor device formed on a surface,
In manufacturing the lead frame,
A portion connecting the wire at the tip of the lead that faces the tip to the tab is formed in the inverted trapezoidal cross section having the processing surface,
Forming a lead portion connected to the wire connecting portion in a square cross section;
A method of manufacturing a semiconductor device, comprising: forming a protrusion projecting on both side surfaces of the lead by partially crushing and pressing the upper surface of the lead portion having the quadrangular cross section. 13. The method of manufacturing a semiconductor device according to claim 12, wherein the protrusion is formed by crushing an upper surface of the lead and forming a groove in a longitudinal direction of the upper surface by press working. 13. The method of manufacturing a semiconductor device according to claim 12, wherein the protrusion is formed by crushing a portion including a side edge of the upper surface of the lead and forming depressions on both sides of the lead by press working. Forming the width of the lead portion that is the rectangular cross section narrower than the width of the lead portion that is the inverted trapezoidal cross section,
A thin thin lead portion is formed at a boundary portion between the lead portion having the inverted trapezoidal cross section and the lead portion having the quadrangular cross section over a predetermined length as compared with other lead portions. Item 13. A method for manufacturing a semiconductor device according to Item 12. The boundary portion of the lead is crushed and pressed, and the first surface that continues to the top surface of the lead to which the wire is connected, the second surface that continues to the first surface, and the second surface. 16. The semiconductor device according to claim 15, wherein the thin lead portion is formed by providing a groove crossing the lead by a third surface continuous to the lead upper surface of the lead portion connected to the wire connecting portion. Production method. The method of manufacturing a semiconductor device according to claim 12, wherein an angle formed between a lower surface and a side surface of the inverted trapezoidal cross section is 100 ° to 120 °. 13. The method of manufacturing a semiconductor device according to claim 12, wherein the tip of the lead is crushed and pressed to form an overhang portion thinner than the lead. 13. The method of manufacturing a semiconductor device according to claim 12, wherein a width dimension of a lower surface of the lead is formed to be equal to or smaller than a dimension between adjacent leads. 13. The method of manufacturing a semiconductor device according to claim 12, wherein a groove or a recess is formed on the lower surface of the lead. (A) A lead frame made of metal having a plurality of leads, a tab having a semiconductor element fixing surface, a plurality of tab suspension leads connected to the tab, and a frame portion connecting the leads and the tab suspension leads is manufactured. And a process of
(B) mounting a semiconductor element on the semiconductor element fixing surface via an adhesive;
(C) electrically connecting the electrode of the semiconductor element and the lead via a wire;
(D) sealing the semiconductor element, the wire, the lead and the tab suspension lead with an insulating resin, and the insulating resin such that the tab suspension lead and the back surface of the lead are exposed from the insulating resin; Forming a sealed body by:
(E) separating the lead and the tab suspension lead from the frame part,
In the manufacture of the lead frame, a lead pattern is formed by punching or etching a metal plate a plurality of times, and at least a part of the lead of the lead frame is opposed to the upper surface covered with the sealing body and the upper surface. A manufacturing method of a semiconductor device formed in an inverted trapezoidal cross section composed of a lower surface exposed from the sealing body, and a side surface connecting the upper surface and both side edges of the lower surface,
In manufacturing the lead frame,
Forming the portion connecting the wire at the tip of the lead that faces the tip to the tab in the inverted trapezoidal cross section;
A thin lead portion is formed at a boundary portion between a portion connecting the wire and a lead portion connected to the wire connecting portion over a predetermined length as compared with other lead portions. Manufacturing method. The boundary portion of the lead is crushed and pressed, and the first surface that continues to the top surface of the lead that connects the wire, the second surface that continues to the first surface, and the second surface. And forming a thin lead portion by providing a groove across the lead by a third surface connected to the upper surface of the lead portion of the lead portion connected to the wire connecting portion,
Forming an angle formed by the second surface and the first surface to be 90 ° or more, and an angle formed by the second surface and the third surface to be an angle of 90 ° or more. The method of manufacturing a semiconductor device according to claim 21. A mounting substrate having a land on the upper surface; and a non-lead type semiconductor device that exposes a lower surface of the lead on a lower surface of the sealing body. The lead of the semiconductor device is formed on the land of the mounting substrate by a conductive adhesive. An electronic device connected to
An electronic device according to claim 1, wherein the semiconductor device is a semiconductor device according to claim 1. A mounting substrate having a land on the upper surface; and a non-lead type semiconductor device that exposes a lower surface of the lead on a lower surface of the sealing body. The lead of the semiconductor device is formed on the land of the mounting substrate by a conductive adhesive. An electronic device connected to
An electronic device according to claim 10, wherein the semiconductor device is a semiconductor device according to claim 10.

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