JP5817513B2 - Lead frame for manufacturing semiconductor device and method for manufacturing semiconductor device - Google Patents

Description

  The present invention relates to a lead frame used for manufacturing a semiconductor device and a method for manufacturing a semiconductor device using the lead frame.

  2. Description of the Related Art In recent years, with the increase in density of board mounting, there has been a demand for downsizing and thinning of semiconductor devices mounted on a board. In order to meet such demands, a conventional lead frame is used, and a semiconductor element mounted on the mounting surface of the lead frame is sealed with a sealing resin, and a part of the lead is exposed on the lower surface side, so-called QFN. Various (Quad Flat Non-lead) type semiconductor devices have been proposed.

  As an example of such a QFN type semiconductor device, as shown in FIG. 11, a semiconductor element 110 mounted on a die pad 200 in which four suspension leads 400 are continuous, a terminal on the upper surface of the semiconductor element 110, and an external terminal 300, a wire 120 that electrically connects to 300, and a sealing resin (not shown) that seals the semiconductor element 110 and the like so as to expose the lower surface of the external terminal 300. An external terminal 300 located in the vicinity of the suspension lead 400 has been proposed as a semiconductor device 100 having a notch 300a that is notched along the suspension lead 400 at the tip (see Patent Document 1).

Japanese Patent No. 4388586

  At present, in the QFN type semiconductor device as described above, the external terminal pitch of 0.65 mm or 0.50 mm is a standard specification. Fine pitches are being advanced, and development and mass production of semiconductor devices having external terminal pitches of 0.40 mm or 0.30 mm are urgently needed.

  In general, the semiconductor device 100 having the configuration shown in FIG. 11 is manufactured using a lead frame in which a die pad 200, a plurality of external terminals 300, and a suspension lead 400 are continuous in a frame-like frame. It is manufactured by performing an etching process or the like on a metal plate on the surface of which a resist film having the pattern shape is formed.

  However, when the fine pitch of the external terminals in the semiconductor device is advanced, the external terminal 300 located closest to the suspension lead 400 in the semiconductor device 100 further approaches the suspension lead 400. If the pitch between the suspension lead 400 and the external terminal 300 located in the vicinity thereof becomes too narrow (for example, the pitch is 80% or less of the thickness of the metal plate), it is difficult to perform etching processing when manufacturing the lead frame. End up. Therefore, in order to solve such a problem, in the semiconductor device 100, the external terminal 300 located closest to the suspension lead 400 has a notch 300a that is notched along the suspension lead 400 at the tip. It has a configuration.

  Thus, the external terminal 300 located in the nearest vicinity of the suspension lead 400 has the notch portion 300a that is notched along the suspension lead 400 at the tip portion thereof, so that the suspension lead 400 and the nearest vicinity thereof are provided. Although the pitch between the external terminal 300 and the external terminal 300 can be set to such an extent that etching can be performed, the distance between the terminal of the semiconductor element 110 mounted on the die pad 200 and the external terminal 300 having the notch portion 300a. There is a problem that wire bonding may be difficult.

  This is because wire bonding between the terminal of the semiconductor element 110 and the external terminal 300 is generally performed using a wire bonding apparatus. As such a wire bonding apparatus, a position obtained by extending a line segment extending in the direction of the external terminal 300 to be connected from the terminal of the semiconductor element 110 by a predetermined distance from a point intersecting the tip of the external terminal 300 is located on the external terminal 300. When a device having a position detection mechanism for detecting the position to be bonded is used, the wire routing angle (the external line segment connecting the terminal of the semiconductor element 110 and the position to be bonded on the external terminal 300 to be connected to the terminal) As the longitudinal direction of the terminal 300, that is, the angle formed with respect to the direction substantially perpendicular to one side of the die pad 200 facing the external terminal 300 increases, it may become difficult to detect the position to be bonded by the position detection mechanism. Particularly, as the fine pitch of the external terminal 300 is reduced and the semiconductor element 110 is miniaturized, the wire routing angle of each external terminal 300 is increased and the width of the external terminal 300 is reduced. It becomes more difficult to detect the position to be bonded, and as a result, there is a problem that wire bonding to the external terminal 300 is extremely difficult and causes poor connection of wires.

  In view of the above problems, the present invention provides high reliability when connecting a wire between a semiconductor element and a lead using a wire bonding apparatus having a predetermined position detection mechanism in manufacturing a semiconductor device, and It is an object of the present invention to provide a lead frame for manufacturing a semiconductor device in which the wire can be easily connected and a method for manufacturing a semiconductor device using the lead frame.

  In order to solve the above problems, the present invention provides a lead frame used for manufacturing a semiconductor device, wherein the semiconductor element mounting portion has a substantially rectangular semiconductor element mounting portion on which a semiconductor element is mounted, and the semiconductor element mounting portion. A plurality of suspension leads that support the semiconductor element mounting portion, and a plurality of leads that are arranged in parallel between the adjacent suspension leads so as to face the semiconductor element mounting portion and surround the semiconductor element mounting portion. The plurality of leads include a first lead provided at a position closest to the suspension lead, and a second to a second lead provided at a position farther from the suspension lead than the first lead. n leads (n is an integer greater than or equal to 2), and the first lead is a first side face located on the side of the suspension lead adjacent to the first lead and a second side face facing the first side face. A thick part having a thickness, a first side of the thick part, the first thin part having a smaller thickness than the thick part, and a second side of the thick part, and being thicker than the thick part. Of the side portion constituting the tip portion of the first lead that is substantially parallel to one side of the semiconductor element mounting portion facing the first lead in a plan view of the lead frame. The center is a line segment substantially perpendicular to one side of the semiconductor element mounting portion, and the plurality of leads is more than the line segment passing through the center of the thick part of the first lead in the parallel direction of the plurality of leads. Provided is a lead frame which is located on the center side in the parallel direction (Invention 1).

  In the present invention, the “line segment passing through the center of the thick part” means the center of the length of the thick part in the plan view of the lead frame (the direction substantially perpendicular to the parallel direction of the plurality of leads). It is a (middle point) and means a line segment passing through the center (middle point) in the width direction of the thick portion (a direction substantially parallel to the parallel direction of the plurality of leads).

  In the above invention (Invention 1), in the plan view of the lead frame, the first lead is opposed to the first lead among the side portions constituting the second thin portion of the first lead. It is preferable to have a protruding portion that protrudes from a side portion that is substantially perpendicular to one side of the mounting portion toward the side in the parallel direction of the plurality of leads (Invention 2).

  In the above inventions (Inventions 1 and 2), at least the first thin portion of the first lead has a cutout portion in which a corner portion of the tip portion of the first thin portion is cut out along the suspension lead. (Invention 3)

  In the above inventions (Inventions 1 to 3), the second to nth leads are substantially parallel to the thickness direction of the lead frame, and the semiconductor element mounting portion faces the second to nth leads. A thick portion having two side surfaces substantially perpendicular to one side, and a thin portion that is continuous with each of both side surfaces of the thick portion and is thinner than the thick portion; In view, the center of the side portion constituting the tip of the second to nth leads that is substantially parallel to one side of the semiconductor element mounting portion that faces the second to nth leads is one side of the semiconductor element mounting portion. A line segment that is substantially perpendicular to the plurality of leads, and is located closer to the center in the parallel direction of the plurality of leads than a line segment that passes through the center of the thick portion of the second to nth leads in the parallel direction of the plurality of leads. It is preferable (Invention 4).

  In the said invention (invention 4), the center of the side part which comprises each front-end | tip part of the said 2nd-nth lead, and the line segment which passes along the center of each thick part of the said 2nd-nth lead, Is preferably shorter than the distance between the center of the side part constituting the tip of the first lead and the line segment passing through the center of the thick part of the first lead (invention). 5).

  In the said invention (invention 5), the center of the side part which comprises each front-end | tip part of the said 2nd-nth lead, and the line segment which passes along the center of each thick part of the said 2nd-nth lead, It is preferable that the distance between each of the plurality of leads is gradually reduced toward the center in the parallel direction of the plurality of leads (Invention 6).

  In the above inventions (Inventions 4 to 6), the second lead is adjacent to the first lead, and at least the second lead has a thin corner portion located on the first lead side. The notch portion formed by notching and the center in the parallel direction of the plurality of leads from the side portion that is substantially perpendicular to one side of the semiconductor element mounting portion that faces the second lead among the side portions constituting the other thin portion It is preferable to have a protruding portion protruding toward the portion side (Invention 7).

  In the said invention (invention 1-7), it is preferable that the front-end | tip part of these some leads is provided with the thin part of the front end side thin part which faces the said semiconductor element mounting part, and is thin (invention 8). .

  Moreover, this invention is a wire which connects each of the several terminal of the semiconductor element mounted in the upper surface of the said semiconductor element mounting part of the lead frame which concerns on the said invention (invention 1-8), and each of these several lead | read | reed. A connection step of connecting one end of each of the plurality of leads to each of the upper surfaces of the plurality of leads using a wire bonding apparatus, wherein the wire bonding apparatus faces the lead to which the one end of the wire is to be connected. Bonded at a point where a line extending from the terminal of the lead wire extends a predetermined distance from a point intersecting a side portion constituting the tip end portion of the lead that is substantially parallel to one side of the semiconductor element mounting portion facing the lead Provided is a method for manufacturing a semiconductor device, characterized by having a position detection mechanism for detecting the position (Invention 9).

  According to the present invention, when connecting a wire between a semiconductor element and a lead using a wire bonding apparatus having a predetermined position detection mechanism in manufacturing a semiconductor device, the wire can be easily and reliably provided. Can be provided, and a semiconductor device manufacturing method using the lead frame can be provided.

FIG. 1 is a plan view showing a lead frame according to an embodiment of the present invention. 2 is a cross-sectional end view taken along line AA in FIG. 1, showing a lead frame according to an embodiment of the present invention. FIG. 3 is a partially enlarged plan view showing a schematic configuration of leads (first to third leads) in one embodiment of the present invention. FIG. 4 is a partially enlarged plan view showing a schematic configuration of a lead (fourth lead) in one embodiment of the present invention. FIG. 5 is a perspective view showing a schematic configuration of leads (first to third leads) according to an embodiment of the present invention. FIG. 6 is a partially enlarged plan view showing a partial configuration of the lead and the semiconductor element mounting portion in one embodiment of the present invention. FIG. 7 is a cut end view showing a manufacturing process of a lead frame according to an embodiment of the present invention. FIG. 8 is a cut end view showing the manufacturing process of the semiconductor device in one embodiment of the present invention. FIG. 9 is a partially enlarged plan view showing a schematic configuration of a tip portion (part 1) of a lead in another embodiment of the present invention. FIG. 10 is a partially enlarged plan view showing a schematic configuration of the leading end portion (No. 2) of the lead according to another embodiment of the present invention. FIG. 11 is a plan view showing a schematic configuration of a conventional QFN type semiconductor device.

Embodiments of the present invention will be described with reference to the drawings.
〔Lead frame〕
1 is a plan view showing a lead frame according to an embodiment of the present invention as viewed from the lower surface side, and FIG. 2 is a cross-sectional view taken along line AA in FIG. 1 showing the lead frame according to the embodiment. FIG. 3 is a partially enlarged plan view showing a schematic configuration of one of a plurality of leads (first to third leads) in the same embodiment, and FIG. 4 is a first plan view in the same embodiment. FIG. 5 is a partially enlarged plan view showing a schematic configuration of four leads, FIG. 5 is a perspective view showing a schematic configuration of leads (first to third leads) in the embodiment, and FIG. 6 is a lead in the embodiment. FIG. 6 is a partial enlarged plan view showing a configuration of a part of (first to fourth leads) and a semiconductor element mounting portion.

  As is apparent from FIGS. 1 to 5, the lead frame 1 according to this embodiment includes a substantially rectangular semiconductor element mounting portion 2 having an upper surface (mounting surface) on which a semiconductor element is mounted, and a semiconductor element mounting portion 2. A plurality of leads 3 that are provided in the periphery so as to face the semiconductor element mounting part 2 and the four corners of the semiconductor element mounting part 2 are continuous and support the semiconductor element mounting part 2. Lead 4 is provided. Note that the lead frame 1 according to the present embodiment has a large number of semiconductor element mounting portions 2 by multi-sided attachment, and each lead 3 is supported by a plurality of tie bars 5 arranged in a grid pattern. In FIG. 1 and FIG. 2, only one semiconductor element mounting portion 2 is shown.

  The semiconductor element mounting portion 2 has a thick portion 21 and a thin portion 22 located on the periphery of the thick portion 21, and is continuous with a frame portion (not shown) via four suspension leads 4. ing. The thickness of the thin portion 22 and the suspension lead 4 is smaller than the thickness of other portions (thick portion 21, thick portions 311 to 341 of the lead 3 to be described later) in the lead frame 1, preferably the thick portion 21. It is approximately half the thickness (see FIG. 2). The thickness of the thin portion 22 is usually about 50 to 120 μm, although it depends on the thickness of the base material used when manufacturing the multifaceted lead frame 1.

  The leads 3 are juxtaposed along each side of the semiconductor element mounting portion 2, and the first leads 31, 31 adjacent to the suspension leads 4 and the second leads adjacent to the first leads 31, 31. 32, 32, third leads 33, 33 adjacent to the second leads 32, 32, and a fourth lead 34 provided between the third leads 33, 33 (see FIG. 1). In the present embodiment, seven (3 in total) leads 3 are arranged in parallel along each side of the semiconductor element mounting portion 2, but the number of leads 3 is the upper surface of the semiconductor element mounting portion 2. It can be changed as appropriate according to the number of terminals of the semiconductor element mounted on the board.

  The first lead 31 is continuous with the first side surface 31a and a thick portion 311 having a first side surface 31a located on the side of the suspension lead 4 adjacent to the first lead 31 and a second side surface 31b facing the first side surface 31a. The first thin portion 312 and the second thin portion 313 continuous with the second side surface 31b (see FIG. 3).

  The second lead 32 and the third lead 33 are first side surfaces 32 a and 33 a located on the end side in the parallel direction of the lead 3 arranged in parallel to face one side of the semiconductor element mounting portion 2, and the lead 3. Consecutive to the thick portions 321 and 331 having the second side surfaces 32b and 33b located on the center side in the parallel direction, the first thin portions 322 and 332 continuing to the first side surfaces 32a and 33a, and the second side surfaces 32b and 33b. The second thin portions 323 and 333 are formed (see FIG. 3).

  The fourth lead portion 34 includes a thick portion 341 having side surfaces 34a, 34a located on the side of the adjacent third lead portions 33, 33, and thin portions 342, 342 continuing to the side surfaces 34a, 34a (see FIG. 4).

  A predetermined position (a region surrounded by a two-dot broken line circle in FIG. 6) of the upper surfaces 31c to 34c of the thick portions 311 to 341 of the first to fourth leads 31 to 34 is the upper surface of the semiconductor element mounting portion 2. This is a position (bonding position) BP to which a wire for electrical connection with a terminal of a semiconductor element mounted on the board is connected.

  The first thin portions 312 to 332 and the second thin portions 313 to 333 of the first to third leads 31 to 33 and the thin portions 342 of the fourth lead 34 are thicker than the thick portions 311 to 341. It is thin, preferably about half the thickness of the thick portions 311 to 341. The thickness of the first thin part 312 to 332, the second thin part 313 to 333, and the thin part 342 depends on the thickness of the base material used when manufacturing the lead frame 1, but is usually 50 to 120 μm. Degree.

In a plan view of the lead frame 1 according to the present embodiment, tip portions of the first to third leads 31 to 33 that are substantially parallel to one side of the semiconductor element mounting portion 2 facing the first to third leads 31 to 33 are shown. The midpoints P1 to P3 of the side portions 31A to 33A to be configured are line segments substantially perpendicular to one side of the semiconductor element mounting portion 2, and the thick portions 311 to 331 of the first to third leads 31 to 33 are included. The lead 3 is positioned closer to the center in the parallel direction of the lead 3 than the line segments L1 to L3 passing through the centers P _{C1 to} P _C3 in the longitudinal direction (direction substantially perpendicular to the parallel direction of the lead 3) and the width direction (parallel direction of the lead 3). Thus, the first to third leads 31 to 33 are configured (see FIG. 3).

  Specifically, the second thin portions 313 to 333 of the first to third leads 31 to 33 are opposed to the first to third leads 31 to 33 among the side portions constituting the second thin portions 313 to 333. Projecting portions 314 to 334 projecting in a substantially triangular shape from the side portions 313A to 333A substantially perpendicular to one side of the semiconductor element mounting portion 2 to the center side in the parallel direction of the lead 3 (see FIGS. 3 and 5) .

  In addition, each of the first to third leads 31 to 33 includes the suspension lead 4 and the protrusions of the corners on the tip side of the first thin portions 312 to 332 and the corners of the thick portions 311 to 331, respectively. It has the notch parts 315-335 cut out along each of the parts 314,324 (refer FIG.3 and FIG.5).

  Further, the corners of the thin portions 342 and 342 of the fourth lead 34 are along the protruding portions 334 and 334 of the second thin portions 333 and 333 of the two third leads 33 and 33 adjacent to the fourth lead 34. And have cutout portions 345 and 345 that are cut out (see FIG. 4).

  The first to third leads 31 to 33 are the midpoints P1 to P3 of the side portions 31A to 33A constituting the tip portions of the first to third leads 31 to 33 and the meat of the first to third leads 31 to 33. Among the distances D1 to D3 with the line segments L1 to L3 passing through the center of the thick portions 311 to 331 in the width direction (parallel direction of the leads 3), the distance D1 in the first lead 31 is the longest, and the center in the parallel direction of the leads 3 The distance D3 in the third lead 33 is configured to be the shortest by gradually decreasing toward the portion side.

The fourth lead 34 has a midpoint P4 of the side 34A constituting the tip of the fourth lead 34 and the longitudinal direction of the thick portion 341 of the fourth lead 34 (a direction substantially orthogonal to the parallel direction of the leads 3). ) And the line segment L4 passing through the center _PC4 in the width direction (parallel direction of the leads 3).

In the present embodiment, the distances D1 to D3 between the midpoints P1 to P3 and the line segments L1 to L3 in the first to third leads 31 to 33 are terminals in the semiconductor element mounted on the upper surface of the semiconductor element mounting portion 2. Depending on the position, terminal pitch, etc., the position to be bonded on each lead 3 can be set appropriately to a degree that can be detected with high accuracy by a wire bonding apparatus having a predetermined position detection mechanism. In particular, the lead angle of the wire in each lead 3 (semiconductor element mounting) due to the fine pitch of the external terminals in the semiconductor device, the miniaturization of the semiconductor element, and the mounting of a plurality of semiconductor elements on the semiconductor element mounting portion 2. The angle of the line connecting the terminal of the semiconductor element mounted on the portion 2 and the bonding position BP of the lead 3 to be connected to the terminal with respect to the longitudinal direction of the lead 3), or the width of each lead 3 It may become narrower. However, even in such a case, since the position to be bonded in each lead 3 can be detected with high accuracy by the wire bonding apparatus, the center P _DP of the semiconductor element mounting portion 2 and the first to fourth leads A line segment L5 connecting the longitudinal and width centers P _{C1 to} P _C4 in the thick portions 311 to 341 of the 31 to 34 is the side portions 31A to 31 that constitute the tip portions of the first to fourth leads 31 to 34. The distances D1 to D4 between the midpoints P1 to P4 and the line segments L1 to L4 in the first to fourth leads 31 to 34 may be set with a margin so as to surely cross 34A (see FIG. 6). .

  According to the lead frame 1 according to the present embodiment having the above-described configuration, the protruding portions 314 to 334 are provided on the second thin portions 313 to 333 of the first to third leads 31 to 33, and the first to first leads. The midpoints P1 to P3 of the side portions 31A to 33A constituting the tip portions of the three leads 31 to 33 are width directions of the thick portions 311 to 331 of the first to third leads 31 to 33 (parallel direction of the leads 3). The wire bonding apparatus used when manufacturing the semiconductor device using the lead frame 1 is located on the side in the parallel direction of the lead 3 with respect to the line segments L1 to L3 passing through the center, A position where a line segment extended from the terminal in the direction of the lead 3 to be connected is extended by a predetermined distance from a point intersecting the side portions 31A to 34A constituting the tip portion of the lead 3 is detected as a bonding position BP. In the case of having a position detection mechanism, the line segment extended in the direction of the lead 3 to be connected from the terminal of the semiconductor element surely intersects the side portions 31A to 34A constituting the tip portion of the lead 3, so that each lead 3 positions to be bonded BP can be detected with high accuracy. As a result, the wire can be reliably connected to the bonding position BP of each lead 3 using the wire bonding apparatus.

  In particular, as the fine pitch of the semiconductor device is reduced, the pitch of the leads 3 is reduced (for example, 0.40 mm, 0.30 mm, etc.), and the semiconductor element mounted on the semi-mounted element mounting portion 2 is reduced in size. The wire routing angle in each lead 3 increases, and the width of the lead 3 decreases. However, even in such a case, the position to be bonded BP of each lead 3 can be detected with high accuracy by the position detection mechanism of the wire bonding apparatus, and the wire 3 is securely connected to the position to be bonded BP of each lead 3. Can be connected.

  Further, the notch portion 315 is provided along the suspension lead 4 and the notch portions 325 to 345 are provided along the protruding portions 314 to 334 of the second thin portions 313 to 333, so that the suspension lead 4 is provided. And the pitch between the protruding portions 314 to 334 and the notched portions 325 to 345 can be set to such an extent that etching can be performed, and the lead frame 1 can be easily manufactured. .

  Further, in the process of manufacturing the semiconductor device using the lead frame 1 according to the present embodiment, a sealing resin is provided below the first thin portions 312 to 332, the second thin portions 313 to 333, and the thin portions 342 and 342. The lead 3 is filled and finally diced for each semiconductor element, and each lead 3 is separated from the tie bar 5. In this case, each lead 3 is divided into the first thin portion 312 to 332 and the second thin portion 313. By having the 333 and the thin portions 342 and 342, it is possible to prevent each lead 3 from falling down in the separated semiconductor device.

[Lead frame manufacturing method]
A method for manufacturing the lead frame 1 according to the above-described embodiment will be described.
7A to 7D are cut end views (end views cut at a position corresponding to the line AA in FIG. 1) showing the manufacturing process of the lead frame 1 according to the present embodiment.

  First, a metal substrate (thickness: 100 to 250 μm) such as copper, copper alloy, 42 alloy (Ni 41% Fe alloy) is prepared as the conductive substrate 40 (see FIG. 7A). In addition, it is preferable to use what the conductive substrate 40 gave the degreasing process, the washing process, etc. to the both surfaces (upper surface and lower surface).

  Next, a photosensitive resist is applied to the upper and lower surfaces of the conductive substrate 40, dried, exposed through a desired photomask, and then developed to form resist patterns 51 and 52 (see FIG. 7B). ). A conventionally well-known thing can be used as a photosensitive resist. 7B, the resist pattern 51a is at a position corresponding to the upper surface of the semiconductor element mounting portion 2 in the lead frame 1, and the resist pattern 51b is the upper surface of the lead 3 in the lead frame 1 (thick portions 311 to 341, In addition, the resist pattern 52 has a position corresponding to the lower surface of the thick portion 21 in the lead frame 1 and a position corresponding to the first thin portions 312 to 332, the second thin portions 313 to 333, and the thin portions 342 and 342. It is formed at a position corresponding to the lower surface of the thick portions 311 to 341. Although not shown, resist patterns are also formed at positions corresponding to the upper surfaces of the suspension leads 4 and the tie bars 5.

  Subsequently, using the resist patterns 51 and 52 as a mask, the conductive substrate 40 is etched using an etching solution (see FIG. 7C). The etching solution used for the etching process can be appropriately selected according to the material of the conductive substrate 40. For example, when a copper substrate is used as the conductive substrate 40, a ferric chloride aqueous solution is generally used as the etching solution, Etching is performed from both surfaces (upper surface and lower surface) of the conductive substrate 40.

  At this time, in the conductive substrate 40, the position corresponding to the lower surface of the thin portion 22 of the semiconductor element mounting portion 2 in the lead frame 1, the first thin portions 312 to 332, the second thin portions 313 to 333, and the thin portions 342 and 342. Since the resist pattern is not formed at the position corresponding to the lower surface of the wire, the position corresponding to the lower surface of the suspension lead 4, and the position corresponding to the lower surface of the tie bar 5, these portions are notched from the lower surface side. That is, half etching is performed. Thereby, the thin part 22 of the semiconductor element mounting part 2 and the first thin part of the lead 3 having a thickness approximately half the thickness of the thick part 21 of the semiconductor element mounting part 2 and the thick parts 311 to 341 of the lead 3. The portions 312 to 332, the second thin portions 313 to 333, the thin portions 342 and 342, the suspension lead 4, and the tie bar 5 can be formed.

  Finally, the resist patterns 51 and 52 remaining on both surfaces (upper surface and lower surface) of the conductive substrate 40 are peeled and removed (see FIG. 7D). Thereby, the lead frame 1 according to the present embodiment can be manufactured.

[Method of Manufacturing Semiconductor Device]
A method for manufacturing a semiconductor device according to an embodiment of the present invention will be described.
8A to 8E are cross-sectional views illustrating the manufacturing steps of the semiconductor device according to one embodiment of the present invention.

  First, a lead frame 1 manufactured by the steps shown in FIGS. 7A to 7D is prepared, and a semiconductor element is formed on the upper surface of the semiconductor element mounting portion 2 of the lead frame 1 by using a die bond material (not shown) or the like. 11 is fixed (see FIG. 8A).

  Next, the lead frame 1 on which the semiconductor element 11 is mounted on the semiconductor element mounting portion 2 is placed on the stage of the wire bonding apparatus, and the wire 12 is connected to the terminal 11a of the semiconductor element 11 using the wire bonding apparatus. One end is connected (FIG. 8B). The wire bonding apparatus has a predetermined distance from a point where a line segment extending in the direction of the lead 3 to be connected from the terminal 11 a of the semiconductor element 11 intersects the side portions 31 </ b> A to 34 </ b> A constituting the tip portion of the lead 3. It has a position detection mechanism for detecting the stretched position as a bonding position BP.

  Then, the position detection mechanism of the wire bonding apparatus detects the bonding positions BP on the upper surfaces of the thick portions 311 to 341 of the leads 3 and connects the other end of the wire 12 to the bonding positions BP ( FIG. 8 (c)).

  At this time, the protrusions 314 to 334 are provided on the second thin portions 313 to 333 of the first to third leads 31 to 33 of the lead frame 1, and the sides constituting the tip portions of the first to third leads 31 to 33 are provided. Leads 3 rather than line segments L1 to L3 in which the midpoints P1 to P3 of the portions 31A to 33A pass through the centers of the thick portions 311 to 331 of the first to third leads 31 to 33 in the width direction (parallel direction of leads 3) Since the line segment extended in the direction of the lead 3 to be connected from the terminal 11a of the semiconductor element 11 is surely placed on the side portions 31A to 34A constituting the tip portion of the lead 3. Since they intersect, the bonding position BP of each lead 3 can be detected with high accuracy. As a result, it is possible to reliably connect a wire to the bonding position BP of each lead 3 using the wire bonding apparatus, and it is possible to cause a poor connection of the wire due to a detection error of the bonding position BP in the wire bonding apparatus. Can be prevented.

  In this way, after all the terminals 11a to be connected in the semiconductor element 11 and the respective leads 3 are connected by the wires 12, the lead frame 1 is accommodated in the molding die, and the thick portions 311 of the respective leads 3 are accommodated. The lower surface of .about.341 is exposed to the outside, and the semiconductor element 11, the semiconductor element mounting portion 2, the lead 3, the suspension lead 4 and the wire 12 are sealed with the sealing resin 13 (see FIG. 8D).

  Subsequently, the lead frame 1 sealed with the sealing resin 13 is taken out from the molding die, and the thickness of the thick portions 311 to 341 facing the tip portion of the lead 3 is exposed to the outside. The parts 311 to 341 and the suspension leads 4 are cut and separated for each semiconductor device 10. Specifically, dicing along the tie bar 5 for each semiconductor element 11 cuts the thick portions 311 to 341 and the suspension leads 4 of each lead 3 and removes the tie bar 5. In this manner, the semiconductor element mounting portion 2, the semiconductor element 11 mounted on the upper surface of the semiconductor element mounting portion 2, and the periphery of the semiconductor element mounting portion 2 so as to be electrically independent of the semiconductor element mounting portion 2. A plurality of external terminals 30, the wires 12 that electrically connect the terminals 11 a and the external terminals 30 of the semiconductor element 11, and the side surfaces of the external terminals 30 that face the lower surface and the front end portion of the external terminals 30. The semiconductor device 10 including the semiconductor element mounting portion 2, each external terminal 30, the suspension lead 4, the semiconductor element 11, and the sealing resin 13 for sealing the wire 12 can be obtained so as to be exposed (FIG. 8 ( e)).

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  In the said embodiment, although the thin parts 312-332,313-333,342 are provided in the side surfaces 31a-33a, 31b-33b, 34a of each lead | read | reed 3, this invention is limited to such an aspect. For example, as shown in FIGS. 9A and 9B, tip-side thin portions 316 to 346 may be provided at the tip portion of each lead 3. By setting it as such an aspect, the area of the thick parts 311-331 notched by the notch parts 315-335 can be made small. In other words, in a semiconductor device manufactured using such a lead frame, the exposed area of external terminals exposed to the outside (corresponding to the thick portions 311 to 341 of the lead 3 in the lead frame) can be increased. As a result, the semiconductor device and a printed board or the like on which the semiconductor device is mounted can be connected better.

  In the said embodiment, although the front-end | tip part of the thick parts 311 to 341 of each lead 3 is comprised by side part 31A-34A substantially parallel to one side of the semiconductor element mounting part 2 which opposes, this invention is this. It is not limited to such an embodiment, and as shown in FIGS. 10A and 10B, the thick portions 311 to 341 protrude toward the tip portion (R shape, substantially U in plan view). (Character shape).

  In the above embodiment, the number of leads 3 facing each side of the semiconductor element mounting portion 2 is an odd number (seven). However, the present invention is not limited to such an embodiment, and the number of leads 3 is an even number. It may be individual. In this case, the lead 3 arranged in parallel between the adjacent suspension leads 4 is changed from the first lead located closest to the suspension lead 4 to the two nth leads ( n is an integer greater than or equal to 2). The thin part of the nth lead located on the n-1st lead side has a cutout part cut out along the protruding part of the n-1st lead, and the thinned parts facing each other in the nth lead. The portion does not have a protruding portion, and a side portion substantially perpendicular to one side of the semiconductor element mounting portion 2 among the side portions constituting the thin portion does not protrude toward the central portion side of the lead portion 3 in the parallel direction. It only needs to extend to the tip of the nth lead.

  In the above-described embodiment, the semiconductor element mounting portion 2 has the thick portion 21 and the thin portion 22 having a peripheral portion subjected to half etching from the lower surface side, but the present invention is limited to such a mode. Instead, the entire semiconductor element mounting portion 2 may be thinner than other portions (thin portions 311 to 341 of the lead 3 to be described later) in the lead frame 1 or the entire semiconductor element mounting portion 2. May have substantially the same thickness as the thick portions 311 to 341 of the lead 3.

  In the said embodiment, although the 2nd-4th leads 32-34 have the notch parts 325-345 cut | disconnected along the protrusion parts 314-334 of the adjacent lead 3, this invention is The pitch of each lead 3 (interval between the corners of the protrusions 314 to 334 and the corners of the adjacent leads 3) is not limited to such an embodiment, and the metal plate is subjected to etching processing or the like. When manufacturing the lead frame 1, the second to fourth leads 32 to 34 may not have the notches 325 to 345 when the etching process is possible. At least the second lead 32 may be provided with a notch 325.

  In the above embodiment, the protrusions 314 to 334 of the first to third leads 31 to 33 have a substantially triangular shape in plan view of the lead frame 1, but the present invention is limited to such an aspect. For example, the projecting portion may have a substantially rectangular shape in plan view of the lead frame. In this case, it is preferable that the shape of the notch in at least the leads (second to fourth leads 32 to 34) other than the first lead 31 is a hook shape corresponding to the shape of the protruding portion.

  The present invention is useful as a lead frame for manufacturing a resin-encapsulated semiconductor device such as a QFN type.

DESCRIPTION OF SYMBOLS 1 ... Lead frame 2 ... Semiconductor element mounting part 3 ... Lead 31-34 ... 1st-4th lead 311-341 ... Thick part 312-332 ... 1st thin part 313-333 ... 2nd thin part 342 ... Thin part 314 to 334... Projection portion 315 to 345... Notch portion 316 to 346... Thin end portion on the tip side 31 A to 34 A .. Side portion P 1 to P 4 ... Middle point L 1 to L 4 ... Line segment 4 ... Suspension lead 11 ... Semiconductor element 11a. ... Wire 13 ... Sealing resin 30 ... External terminal

Claims (9)

A lead frame used for manufacturing a semiconductor device,
A substantially rectangular semiconductor element mounting portion on which the semiconductor element is mounted on the upper surface;
A plurality of suspension leads for supporting the semiconductor element mounting portion;
A plurality of leads arranged in parallel between each of the adjacent suspension leads so as to face the semiconductor element mounting portion and to surround the semiconductor element mounting portion;
The plurality of leads include a first lead provided at a position closest to the suspension lead, and second to n-th leads (n) provided at positions farther from the suspension lead than the first lead. Is an integer greater than or equal to 2),
The first lead includes a thick side portion having a first side surface located on the side of the suspension lead adjacent to the first lead and a second side surface facing the first side surface, and a first side surface of the thick portion. A first thin portion that is continuous and thinner than the thick portion, and a second thin portion that is continuous with the second side surface and is thinner than the thick portion,
In the plan view of the lead frame, the center of the side portion constituting the tip portion of the first lead that is substantially parallel to one side of the semiconductor element mounting portion facing the first lead is on one side of the semiconductor element mounting portion. It is a substantially vertical line segment, and is positioned closer to the center side in the parallel direction of the plurality of leads than a line segment passing through the center of the thick portion of the first lead in the parallel direction of the plurality of leads. Lead frame characterized by.   In the plan view of the lead frame, the first lead is a side that is substantially perpendicular to one side of the semiconductor element mounting portion that faces the first lead among the side portions that constitute the second thin portion of the first lead. 2. The lead frame according to claim 1, further comprising a protruding portion that protrudes from a portion toward a parallel central portion of the plurality of leads.   At least the first thin portion of the first lead has a cutout portion formed by cutting a corner portion of a tip portion of the first thin portion along the suspension lead. The described lead frame. The second to nth leads have two side faces that are substantially parallel to the thickness direction of the lead frame and substantially perpendicular to one side of the semiconductor element mounting portion that faces the second to nth leads. A thick portion, and continuous with each of both side surfaces of the thick portion, and a thin portion having a thickness smaller than the thick portion,
In the plan view of the lead frame, the center of the side part constituting the tip part of the second to nth leads that is substantially parallel to one side of the semiconductor element mounting part that faces the second to nth leads is the semiconductor. A line segment that is substantially perpendicular to one side of the element mounting portion and that is parallel to the plurality of leads rather than a line segment that passes through the center of the thick portion of the second to nth leads in the parallel direction of the plurality of leads. The lead frame according to any one of claims 1 to 3, wherein the lead frame is located on the center side.   Each distance between the center of the side part constituting the tip of each of the second to nth leads and the line segment passing through the center of the thick part of each of the second to nth leads is 5. The lead frame according to claim 4, wherein the distance is shorter than a distance between a center of a side portion constituting a tip portion of one lead and a line segment passing through a center of a thick portion of the first lead.   Each distance between the center of the side part constituting the tip of each of the second to n-th leads and the line segment passing through the center of the thick part of each of the second to n-th leads is the plurality The lead frame according to claim 5, wherein the lead frame gradually decreases toward the center in the parallel direction of the lead. The second lead is adjacent to the first lead;
At least the second lead is opposed to the second lead among the notches formed by cutting out the corners of one thin portion located on the first lead side and the side portions constituting the other thin portions. 7. A projecting portion that projects from a side portion substantially perpendicular to one side of the semiconductor element mounting portion to the center side in the parallel direction of the plurality of leads. Lead frame.   The lead frame according to any one of claims 1 to 7, wherein a tip end side thin portion having a small thickness is provided at a tip portion of the plurality of leads so as to face the semiconductor element mounting portion. . One end portion of a wire connecting each of the plurality of terminals of the semiconductor element mounted on the upper surface of the semiconductor element mounting portion of the lead frame according to any one of claims 1 to 8 and each of the plurality of leads, Including a connection step of connecting to each of the upper surfaces of the plurality of leads using a wire bonding apparatus;
In the wire bonding apparatus, a lead extending from a terminal of the semiconductor element toward the lead to which one end of the wire is connected is substantially parallel to one side of the semiconductor element mounting portion facing the lead. A method for manufacturing a semiconductor device, comprising: a position detection mechanism that detects a point extended by a predetermined distance from a point that intersects a side part that constitutes the tip part of the tip part as a position to be bonded.

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