JP6573157B2 - Lead frame and manufacturing method thereof, and semiconductor device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a lead frame and a manufacturing method thereof, and a semiconductor device and a manufacturing method thereof.

  In recent years, it has been required to reduce the size and thickness of a semiconductor device mounted on a substrate. In order to meet such demands, conventionally, a lead frame is used, and a semiconductor element mounted on the mounting surface is sealed with a sealing resin, and a part of the lead is exposed on the back surface side, so-called QFN. Various (Quad Flat Non-lead) type semiconductor devices have been proposed.

  However, in the case of a QFN having a conventional general structure, since the package becomes larger as the number of terminals increases, there is a problem that it is difficult to ensure mounting reliability. On the other hand, as a technique for realizing a multi-pin QFN, development of a package in which external terminals are arranged in two rows is underway (for example, Patent Document 1). Such a package is also called a DR-QFN (Dual Row QFN) package.

JP 2006-19767 A

  In recent years, in producing a DR-QFN package, it has been required to increase the number of leads (number of pins) without changing the chip size. On the other hand, conventionally, in order to increase the number of pins, a method of increasing the package size has been taken. However, there is a limit in increasing the package size due to restrictions on mounting the package on the electronic device. In addition, as the package size increases, the length of the inner lead increases, which causes a problem that the inner lead is likely to be deformed.

  The present invention has been made in consideration of such points, and the lead frame capable of preventing the deformation of the inner lead and increasing the number of terminal portions (number of pins) connected to the outside, and the lead frame thereof It is an object to provide a manufacturing method, a semiconductor device, and a manufacturing method thereof.

  The present invention is a lead frame for a semiconductor device, and includes a plurality of lead portions each including a die pad on which a semiconductor element is mounted and an inner lead provided around the die pad and extending inward from the terminal portion. And a lead connection part provided on the tip side of the inner lead, and a plurality of recesses are formed on the surface of the lead connection part at intervals along the length direction of the lead connection part, The lead frame is characterized in that a thick portion is formed between the concave portions adjacent to each other in the lead connection portion.

  The lead frame according to the present invention is characterized in that the lead connection portion is a connection ring surrounding the die pad.

  The present invention is the lead frame characterized in that the plurality of concave portions are arranged at equal intervals along the length direction of the lead connecting portion.

  The present invention is the lead frame characterized in that a plurality of the thick portions are provided, and some of the thick portions are larger than the other thick portions.

  The present invention is the lead frame characterized in that the lead connecting portion is supported by at least one inner lead.

  The present invention is the lead frame characterized in that a connecting bar for connecting the lead connecting portion and the die pad is provided, and the die pad is supported by the connecting bar.

  According to the present invention, the terminal portions of the lead portions have external terminals, respectively, and the external terminals are alternately arranged in a staggered manner as viewed from the plane so as to be located inside and outside between the adjacent lead portions. It is the lead frame characterized by the above.

  The present invention is the lead frame characterized in that the inner lead is thinner than the terminal portion.

  The present invention is a semiconductor device, a semiconductor device mounted on a die pad, a plurality of lead portions provided around the die pad, each including a terminal portion and an inner lead extending inward from the terminal portion, and the die pad A sealing member for sealing the element, the connecting member for electrically connecting the semiconductor element and the inner lead of each lead portion, the die pad, the plurality of lead portions, the semiconductor element, and the connecting member; The semiconductor device is characterized in that a resin recess is formed between the lead portion and the die pad on the back surface of the sealing resin.

  In the present invention, a plurality of thick portions are disposed between the die pad and the lead portion, and the plurality of thick portions are separated from the die pad and the lead portion and are spaced apart from each other. It is a semiconductor device characterized by the above.

  The present invention is the semiconductor device, wherein the semiconductor element and the thick part are connected by a connecting member.

  In the present invention, a plurality of the thick portions are provided, and among the plurality of thick portions, some thick portions are larger than other thick portions, and a plurality of connection members are provided in the some thick portions. Are connected to each other.

  The present invention provides a die pad on which a semiconductor element is mounted, a plurality of lead portions provided around the die pad, each including a terminal portion and an inner lead extending inward from the terminal portion, and provided on a tip side of the inner lead. A lead frame manufacturing method comprising: a lead connection portion provided on a tip end side of the inner lead; and a step of preparing a metal substrate, and etching the metal substrate to form the metal substrate on the metal substrate. A step of forming a die pad, the lead portion, and the lead connection portion, and a plurality of recesses are formed on the surface of the lead connection portion at intervals along the length direction of the lead connection portion, A lead frame manufacturing method characterized in that a thick portion is formed between the recesses adjacent to each other in the lead connection portion. That.

  The present invention provides a method of manufacturing a semiconductor device, comprising: preparing the lead frame; mounting the semiconductor element on the die pad of the lead frame; and the semiconductor element and the inner lead of each lead portion. A step of electrically connecting with a connecting member, a step of sealing the die pad, the plurality of lead portions, the semiconductor element, and the connecting member with a sealing resin; and And a step of removing at least a part of the lead connecting portion.

  ADVANTAGE OF THE INVENTION According to this invention, while preventing a deformation | transformation of an inner lead, the number of terminal parts (pin number) connected with the exterior can be increased.

FIG. 1 is a plan view showing a lead frame according to a first embodiment of the present invention. 2A is a cross-sectional view showing the lead frame according to the first embodiment of the present invention (cross-sectional view taken along the line IIA-IIA in FIG. 1), and FIG. 2B is a cross-sectional view of the first embodiment of the present invention. Sectional drawing which shows the lead frame by a form (IIB-IIB sectional view taken on the line of FIG. 1). FIG. 3 is a plan view showing the semiconductor device according to the first embodiment of the present invention. 4 is a sectional view showing the semiconductor device according to the first embodiment of the present invention (a sectional view taken along line IV-IV in FIG. 3). 5A to 5F are cross-sectional views showing a method for manufacturing a lead frame according to the first embodiment of the present invention. 6A to 6G are cross-sectional views showing a method for manufacturing a semiconductor device according to the first embodiment of the present invention. FIG. 7 is a plan view showing a semiconductor device according to a second embodiment of the present invention. FIG. 8 is a plan view showing a semiconductor device according to a modification of the second embodiment of the present invention. FIG. 9 is a plan view showing a lead frame according to a third embodiment of the present invention. FIG. 10 is a plan view showing a semiconductor device according to the third embodiment of the present invention. FIG. 11 is a plan view showing a semiconductor device according to a modification of the third embodiment of the present invention.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. Note that, in the following drawings, the same portions are denoted by the same reference numerals, and some detailed description may be omitted.

Construction of the lead frame initially, to FIG. 1 and FIG. 2 (a) (b), will be outlined in the lead frame according to the present embodiment. 1 and 2 (a) and 2 (b) are views showing a lead frame according to the present embodiment.

  As shown in FIG. 1 and FIGS. 2A and 2B, the lead frame 10 is provided around a die pad 11 on which a semiconductor element 21 (described later) is mounted, the semiconductor element 21 and an external circuit (not shown). A plurality of elongated lead portions 12A and 12B for connecting the lead pad 12) and a connection ring (lead connecting portion) 14 provided between the die pad 11 and the lead portions 12A and 12B.

  The lead frame 10 includes a plurality of unit lead frames 10a, each of which corresponds to a semiconductor device 20 (described later). The unit lead frame 10a is an area located inside the imaginary line in FIG. The plurality of unit lead frames 10 a are connected to each other via support leads (support members) 13. The support leads 13 support the die pad 11 and the lead portions 12A and 12B, and extend along the X direction and the Y direction perpendicular to the X direction.

  The die pad 11 has a substantially rectangular plane shape, and its four sides extend along either the X direction or the Y direction. The die pad 11 is supported on the connection ring 14 by a plurality (eight) of connecting bars 19. On the other hand, since the suspension leads are not provided at the four corners of the die pad 11, the lead portions 12 </ b> A and 12 </ b> B can be arranged near the four corners of the die pad 11. For this reason, compared with the case where the die pad 11 is supported via a suspension lead, the number of lead parts 12A and 12B can be increased.

  Next, the configuration of the lead portions 12A and 12B will be further described.

  As shown in FIGS. 1 and 2A and 2B, each lead portion 12A, 12B has an inner lead 51, a connection lead 52, and a terminal portion (first terminal portion) 53, respectively. . Among these, the inner lead 51 extends inward (on the die pad 11 side) from the terminal portion 53 and is connected to the connection ring 14 at the tip thereof. In this case, the inner lead 51 extends perpendicularly or inclined with respect to the support lead 13 as viewed from above. An inner terminal 15 </ b> A is formed on the surface of the distal end portion of the inner lead 51. The internal terminal 15A is a region that is electrically connected to the semiconductor element 21 via a bonding wire 22 as will be described later. For this reason, the plating part 25 which improves adhesiveness with the bonding wire 22 is provided on the internal terminal 15A.

  The connection lead 52 of each lead part 12A, 12B is located on the outer side (support lead 13 side) than the terminal part 53, and the base end part thereof is connected to the support lead 13. The connection lead 52 extends perpendicular to the support lead 13 to which the connection lead 52 is coupled.

  Further, as shown in FIGS. 2A and 2B, the inner leads 51 and the connection leads 52 of the lead portions 12A and 12B are thinned by half etching from the back side (opposite side of the surface on which the semiconductor element 21 is mounted), respectively. Is formed. On the other hand, the terminal portion 53 has the same thickness as the die pad 11 and the support lead 13 without being half-etched. As described above, since the inner leads 51 and the connecting leads 52 are thinner than the terminal portions 53, the narrow lead portions 12A and 12B can be formed with high accuracy, and the semiconductor is small and has a large number of pins. A device 20 can be obtained. Half-etching means that the material to be etched is etched halfway in the thickness direction.

  External terminals 17A and 17B that are electrically connected to external mounting boards (not shown) are formed on the back surfaces of the terminal portions 53 of the lead portions 12A and 12B, respectively. The external terminals 17A and 17B are exposed outward from the semiconductor device 20 after the semiconductor device 20 (described later) is manufactured.

  In this case, the external terminals 17A and 17B of the plurality of lead portions 12A and 12B are alternately arranged in a zigzag shape as viewed from the plane so as to be located inside and outside between the adjacent lead portions 12A and 12B. That is, around the die pad 11, a lead portion 12A having an external terminal (inside external terminal) 17A positioned relatively inside (die pad 11 side) and an external terminal positioned relatively outside (support lead 13 side). Lead portions 12B having (outside external terminals) 17B are alternately arranged over the entire circumference. Thereby, even when the lead portions 12A and 12B are provided close to each other, a problem that the external terminals 17A and 17B come into contact with each other is prevented. In this case, the external terminal 17A and the external terminal 17B all have the same planar shape.

  As shown in FIG. 1, the plurality of external terminals 17 </ b> A are all arranged along a straight line parallel to one side of the die pad 11 when viewed from above. Further, the plurality of external terminals 17B are all arranged on a straight line parallel to one side of the die pad 11 when viewed from above. That is, the plurality of external terminals 17A and 17B are arranged in two rows along a straight line parallel to either the X direction or the Y direction.

  The adjacent lead portions 12A and 12B are in a shape that is electrically insulated from each other after the semiconductor device 20 (described later) is manufactured. Each lead portion 12A, 12B has a shape that is electrically insulated from the die pad 11 after the semiconductor device 20 is manufactured.

  In this case, it is preferable that the interval between the adjacent lead portions 12A and 12B be 90 μm to 150 μm (90 μm or more and 150 μm or less; the same applies hereinafter). In this way, by setting the interval between the lead portions 12A and 12B to 90 μm or more, a through portion between the adjacent lead portions 12A and 12B can be reliably formed by etching. Further, by setting the interval to 150 μm or less, the number of external terminals 17A and 17B (number of pins) of each semiconductor device 20 can be secured at a certain number or more. Specifically, the number of external terminals 17A and 17B (number of pins) can be set to 80 pins to 250 pins, for example.

  Next, the configuration of the connection ring 14 and the connecting bar 19 will be described.

  As shown in FIG. 1 and FIG. 2A, the connection ring 14 is provided on the tip side of the inner lead 51 of the lead portions 12 </ b> A and 12 </ b> B and is disposed so as to surround the die pad 11. The connection ring 14 has a substantially rectangular shape as a whole, and each side thereof extends along the X direction or the Y direction. Thus, by connecting the connection ring 14 to the tip side of each inner lead 51, the deformation of the inner lead 51 can be prevented only by the connection ring 14.

  Inner leads 51 of the lead portions 12 </ b> A and 12 </ b> B are coupled to the outer peripheral edge (the support lead 13 side peripheral edge) of the connection ring 14. In this case, the connection ring 14 is connected to and supported by all the inner leads 51, but is not limited thereto, and may be connected to and supported by only some of the inner leads 51.

  A plurality of recesses 14 c are formed on the surface of the connection ring 14 at intervals along the longitudinal direction of the connection ring 14. The recess 14c is formed by half etching and has a certain depth without penetrating in the thickness direction. Moreover, the recessed part 14c is formed in the width direction substantially center part of the connection ring 14, and the area | region which is not half-etched is formed in the width direction both sides of the recessed part 14c. Each recess 14 c is formed near the tip of each inner lead 51.

  In this case, the cross section of the recess 14c (the cross section perpendicular to the longitudinal direction of the connection ring 14) is substantially concave or U-shaped. Moreover, although the planar shape of the recessed part 14c is a rectangular shape, it is not restricted to this, It is good also as a circular shape, an ellipse shape, a polygonal shape, etc. In addition, in this Embodiment, although the recessed part 14c is provided over the perimeter including the four corners of the connection ring 14, for example, you may provide in the perimeter except the four corners of the connection ring 14. . Moreover, although the recessed part 14c is formed regularly (equal intervals) along the longitudinal direction of the connection ring 14, it is not restricted to this, You may form it at irregular intervals.

  In the connection ring 14, thick portions 28 are formed between the recesses 14 c adjacent to each other. Each thick portion 28 is formed between the tips of the inner leads 51 adjacent to each other. The thick portion 28 is not half-etched and has the same thickness as the die pad 11 and the support lead 13. That is, the concave portions 14 c and the thick portions 28 are alternately arranged along the length direction of the connection ring 14.

  In the present embodiment, the recesses 14 c are provided near the tips of all the inner leads 51. However, the present invention is not limited to this, and the recesses 14 c may be provided only near the tips of some inner leads 51.

  Since the recess 14c is provided in this manner, the volume of the connection ring 14 is reduced, so that the connection ring 14 can be easily removed by etching as will be described later.

  On the other hand, each connecting bar 19 connects the connection ring 14 and the die pad 11 to each other, and extends along a straight line parallel to either the X direction or the Y direction. In this case, eight connection bars 19 are provided, and two connection bars 19 are connected to all four sides of the connection ring 14. The connecting bar 19 has the same thickness as the die pad 11 and the support lead 13 without being half-etched. By providing the connecting bar 19 in this manner, the die pad 11 can be supported by the connection ring 14 without using a suspension lead. Further, the connecting bar 19 may be partially half-etched. Thereby, the adhesiveness with the sealing resin 23 can be improved. The half-etched portion may be formed in a line shape along the longitudinal direction of the connecting bar 19 or in a round dimple shape. At this time, the connecting bar 19 and the concave portion 14c of the connecting ring 14 are not connected to each other so as not to be deformed between the connecting bar 19 and the die pad 11 connected to the connecting bar 19 or the lead portions 12A and 12B. Preferably it is. The connecting bar 19 may be connected to the four corners of the die pad 11.

  The lead frame 10 described above is made of a metal such as copper, copper alloy, 42 alloy (Ni 42% Fe alloy) as a whole. The lead frame 10 can have a thickness of 80 μm to 250 μm, although it depends on the configuration of the semiconductor device 20 to be manufactured.

  In FIG. 1, the lead portions 12 </ b> A and 12 </ b> B are arranged along all four sides of the die pad 11, but the present invention is not limited to this. For example, the lead portions 12 </ b> A and 12 </ b> B are arranged along only two opposite sides of the die pad 11. May be. In this case, the connection ring 14 may be supported only by the lead portions 12A and 12B arranged along the two sides.

Configuration of Semiconductor Device Next, the semiconductor device according to the present embodiment will be described with reference to FIGS. 3 and 4 are diagrams showing a semiconductor device (DR-QFN (Dual Row QFN) type) according to the present embodiment.

  As shown in FIGS. 3 and 4, the semiconductor device (semiconductor package) 20 includes a die pad 11, a plurality of lead portions 12 </ b> A and 12 </ b> B disposed around the die pad 11, and a semiconductor element 21 mounted on the die pad 11. And a plurality of bonding wires (connection members) 22 for electrically connecting the lead portions 12A and 12B and the semiconductor element 21. The die pad 11, the lead portions 12 </ b> A and 12 </ b> B, the semiconductor element 21 and the bonding wire 22 are resin-sealed with a sealing resin 23.

  Among these, the die pad 11 and the lead portions 12A and 12B are manufactured from the lead frame 10 described above. The configurations of the die pad 11 and the lead portions 12A and 12B are substantially the same as those shown in FIGS. 1A, 1B, 2A, and 2B except for the region not included in the unit lead frame 10a. The detailed explanation is omitted.

  On the other hand, the connection ring 14 described above is resin-sealed with the sealing resin 23 and then removed from the back surface side by etching. Further, the connection bar 19 is separated from the lead portions 12A and 12B and is connected only to the die pad 11.

  As described above, with the removal of the connection ring 14, a resin recess 27 is formed in a region between the lead portions 12 </ b> A and 12 </ b> B and the die pad 11 on the back surface of the sealing resin 23. The resin recess 27 substantially corresponds to the shape of the connection ring 14 and has a planar rectangular shape (ring shape). In the resin recess 27, a plurality of protrusions 27a made of a part of the sealing resin 23 protrude to the back side (see FIG. 4). Each of the protrusions 27a has a shape corresponding to the recess 14c of the connection ring 14 described above. The protrusions 27 a are arranged at intervals from each other along the longitudinal direction of the resin recess 27. The resin recess 27 may be filled with the same or different type of insulating resin as the sealing resin 23.

  On the other hand, as the semiconductor element 21, various semiconductor elements generally used in the past can be used, and are not particularly limited. For example, an integrated circuit, a large scale integrated circuit, a transistor, a thyristor, a diode, or the like is used. it can. The semiconductor element 21 has a plurality of electrodes 21a to which bonding wires 22 are attached. The semiconductor element 21 is fixed to the surface of the die pad 11 with an adhesive 24 such as a die bonding paste.

  Each bonding wire 22 is made of a material having good conductivity such as gold or copper. Each bonding wire 22 has one end connected to the electrode 21a of the semiconductor element 21 and the other end connected to the internal terminal 15A of each lead portion 12A, 12B. The internal terminal 15 </ b> A is provided with a plating portion 25 that improves the adhesion with the bonding wire 22.

  As the sealing resin 23, a thermosetting resin such as a silicone resin or an epoxy resin, or a thermoplastic resin such as a PPS resin can be used. The total thickness of the sealing resin 23 can be about 500 μm to 1000 μm. In FIG. 3, the display of the sealing resin 23 located on the surface side of the die pad 11 and the lead portions 12A and 12B is omitted.

  Note that one side of the semiconductor device 20 may be, for example, 8 mm to 16 mm.

Manufacturing Method of Lead Frame Next, a manufacturing method of the lead frame 10 shown in FIGS. 1 and 2A and 2B will be described with reference to FIGS. 5A to 5F are cross-sectional views (corresponding to FIG. 2A) showing the manufacturing method of the lead frame 10. FIG.

  First, as shown in FIG. 5A, a flat metal substrate 31 is prepared. As the metal substrate 31, a substrate made of a metal such as copper, a copper alloy, or a 42 alloy (Ni 42% Fe alloy) can be used. In addition, it is preferable to use what the metal substrate 31 performed the degreasing | defatting etc. on both surfaces, and performed the washing process.

  Next, photosensitive resists 32a and 33a are applied to the entire front and back surfaces of the metal substrate 31, respectively, and dried (FIG. 5B). As the photosensitive resists 32a and 33a, conventionally known resists can be used.

  Subsequently, the metal substrate 31 is exposed through a photomask and developed to form etching resist layers 32 and 33 having desired openings 32b and 33b (FIG. 5C).

  Next, the etching resist layers 32 and 33 are used as an anticorrosion film, and the metal substrate 31 is etched with an etching solution (FIG. 5D). Thereby, the outer shape of the die pad 11, the plurality of lead portions 12A and 12B, the connection ring 14 and the connecting bar 19 is formed. The corrosive liquid can be appropriately selected according to the material of the metal substrate 31 to be used. For example, when a copper alloy is used as the metal substrate 31, a ferric chloride aqueous solution is usually used from both sides of the metal substrate 31. It can be performed by spray etching.

  Thereafter, the etching resist layers 32 and 33 are removed and removed (FIG. 5E).

  In the above description, the case where spray etching is performed from both sides of the metal substrate 31 has been described as an example. However, the present invention is not limited to this. For example, two stages of spray etching may be performed for each side of the metal substrate 31. Specifically, first, etching resist layers 32 and 33 having a predetermined pattern are formed (see FIG. 5C), and then an etching-resistant sealing layer (not shown) is formed on the back side of the metal substrate 31. In this state, only the surface side of the metal substrate 31 is etched. Next, the sealing layer on the back side is peeled off, and a sealing layer (not shown) is provided on the front side of the metal substrate 31. At this time, the sealing layer on the surface side also enters the recess on the surface side of the etched metal substrate 31. Subsequently, only the exposed back surface of the metal substrate 31 is etched, and then the sealing layer on the front surface side is peeled to form the outer shape of the die pad 11 and the plurality of lead portions 12A and 12B. By performing spray etching on each side of the metal substrate 31 in this way, the effect of easily avoiding deformation of the lead portions 12A and 12B can be obtained.

  Next, in order to improve the adhesion between the bonding wire 22 and each internal terminal 15A, each internal terminal 15A is subjected to a plating process to form a plated portion 25 (FIG. 5 (f)). In this case, the type of plating selected is not limited as long as the adhesion to the bonding wire 22 can be ensured. For example, single-layer plating such as Ag or Au may be used, or Ni / Pd or Ni / Pd / Au may be used. Multi-layer plating laminated in this order may be used. Further, the plating part 25 may be provided only on the connection part with the bonding wire 22 of the lead parts 12A and 12B, or may be provided on the entire surface of the lead frame 10.

  In this way, the lead frame 10 shown in FIGS. 1 and 2A and 2B is obtained.

Method for Manufacturing Semiconductor Device Next, a method for manufacturing the semiconductor device 20 shown in FIGS. 3 and 4 will be described with reference to FIGS. 6A to 6G are cross-sectional views (a diagram corresponding to FIG. 4) illustrating the method for manufacturing the semiconductor device 20.

  First, the lead frame 10 is obtained by, for example, the method shown in FIGS. 5A to 5F (described above) (FIG. 6A).

  Next, the semiconductor element 21 is mounted on the die pad 11 of the lead frame 10. In this case, for example, the semiconductor element 21 is mounted on the die pad 11 and fixed using an adhesive 24 such as a die bonding paste (die attachment step) (FIG. 6B).

  Next, the electrodes 21a of the semiconductor element 21 and the plating portions 25 (internal terminals 15A) of the lead portions 12A and 12B are electrically connected to each other by bonding wires (connection members) 22 (wire bonding step). (FIG. 6C).

  At this time, the lead frame 10 is placed on the heat block 36 of the wire bonding apparatus. Next, the inner lead 51 of each lead part 12A, 12B is heated from the back side by the heat block 36. At the same time, while applying ultrasonic waves through a capillary (not shown) of the wire bonding apparatus, each electrode 21a of the semiconductor element 21 and the plating part 25 of each of the lead parts 12A and 12B are bonded to the bonding wire 22 respectively. Use for electrical connection.

  Next, the sealing resin 23 is formed by injection molding or transfer molding of a thermosetting resin or a thermoplastic resin to the lead frame 10 (FIG. 6D). In this way, the die pad 11, the plurality of lead portions 12A and 12B, the semiconductor element 21, and the bonding wire 22 are sealed with resin.

  Subsequently, an etching resist layer 34 having a predetermined opening 34a is provided on the back surface of the lead frame 10 and the sealing resin 23 (FIG. 6E).

  During this time, a photosensitive resist is first applied to the entire back surface of the lead frame 10 and the sealing resin 23. Subsequently, the photosensitive resist is exposed through a photomask and developed to form an etching resist layer 34 having a desired opening 34a. As the etching resist layer 34, for example, a known dry film resist can be used.

  In this case, the etching resist layer 34 covers the entire back surface of the lead frame 10 and the sealing resin 23 except for the opening 34a. The opening 34a substantially corresponds to the position of the connection ring 14 and has a substantially rectangular band shape when viewed from above, and the back surface (metal part) of the connection ring 14 is exposed from the opening 34a. Yes.

  Next, the etching resist layer 34 is used as an anticorrosion film, and the lead frame 10 is etched with an etching solution (FIG. 6F). At this time, the corrosive liquid entering from the opening 34 a dissolves and removes the entire connection ring 14. At this time, a part of the lead parts 12 </ b> A and 12 </ b> B or a part of the connecting bar 19 may be removed together with the connection ring 14. In this case, the surface of the connection ring 14 is provided with a plurality of recesses 14c spaced apart from each other, so that the corrosion liquid entering from the opening 34a does not dissolve the lead portions 12A and 12B more than necessary. The connection ring 14 can be removed appropriately. By removing the connection ring 14, a resin recess 27 is formed at a position corresponding to the connection ring 14. In addition, protrusions 27a are formed in the resin recesses 27 at positions corresponding to the respective recesses 14c.

  In this way, the connection ring 14 is removed, the lead portions 12A and 12B are separated from each other, and the connection bars 19 and the lead portions 12A and 12B are separated. In addition, the corrosion liquid can use the ferric chloride aqueous solution, for example similarly to the above (refer FIG.5 (d)).

  Next, the etching resist layer 34 is peeled and removed. Thereafter, the lead frame 10 and the sealing resin 23 between the semiconductor elements 21 are diced to separate the lead frame 10 for each unit lead frame 10a (see FIG. 1). At this time, the lead frame 10 and the sealing resin 23 between the unit lead frames 10a may be cut while rotating a blade (not shown) made of, for example, a diamond grindstone. Note that after removing the etching resist layer 34, a step of filling the resin recess 27 with the same or different type of insulating resin as the sealing resin 23 may be provided.

  In this way, the semiconductor device 20 shown in FIGS. 3 and 4 is obtained (FIG. 6G).

  As described above, according to the present embodiment, the connection ring 14 is provided so as to surround the die pad 11 on the distal end side of the inner lead 51 of each lead portion 12A, 12B. Therefore, when the lead frame 10 is manufactured by etching (FIGS. 5A to 5F), the tip of each inner lead 51 can be fixed to the connection ring 14, so that the inner lead 51 is deformed. Can be prevented. Further, since the deformation of the inner leads 51 is prevented, the width can be reduced or the number of the inner leads 51 can be increased. As a result, the semiconductor device 20 can be increased in density.

  Further, according to the present embodiment, the concave portions 14c are provided in a dot shape along the connecting ring 14 at regular intervals, and the thick portions 28 are formed between the concave portions 14c, so that the connecting ring 14 is removed by etching. In doing so, it is possible to appropriately adjust the entry and dissolution of the corrosive liquid. Furthermore, when the connection ring 14 is removed by etching, the tip shape of the inner lead 51 located in the vicinity of each recess 14c can be formed substantially uniformly.

  In the present embodiment, the case where the entire connection ring 14 is removed by etching has been described as an example. However, the present invention is not limited to this. For example, only a part of the connection ring 14 may be removed by etching, and a part of the connection ring 14 that has not been removed may be left in the semiconductor device 20.

  Moreover, in the said embodiment, the case where the external terminals 17A and 17B are alternately arrange | positioned in 2 rows in zigzag form seeing from a plane so that it may be located inside and outside between adjacent lead part 12A and 12B is an example. Explained. However, the present invention is not limited to this, and all of the external terminals along each side of the die pad 11 may be aligned on a straight line (QFN type). Alternatively, the external terminals 17A and 17B of the lead portions 12A and 12B along each side of the die pad 11 may be arranged in three or more rows.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 7 is a plan view showing a semiconductor device according to the second embodiment of the present invention. The second embodiment shown in FIG. 7 is different in that the thick portion 28 is left inside the semiconductor device 20A, and other configurations are substantially the same as those in the first embodiment described above. In FIG. 7, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  A semiconductor device 20A shown in FIG. 7 is manufactured from the lead frame 10 shown in FIGS. 1 and 2A and 2B, and the thick portion 28 is left without being completely removed. Each constitutes a terminal portion (second terminal portion). The thick portions 28 are arranged at intervals from each other along all four sides (four sides parallel to the X direction or the Y direction in FIG. 7) around the die pad 11. The thick portions 28 are arranged at equal intervals between the die pad 11 and the lead portions 12A and 12B.

  In this case, a portion of the connecting ring 14 of the lead frame 10 positioned around each recess 14c is sealed with the sealing resin 23 and then removed from the back side by etching. On the other hand, each thick portion 28 is separated from the die pad 11, the lead portions 12A and 12B, and the other thick portions 28, and constitutes a terminal portion electrically independent of these members. The thick portion 28 is not half-etched and has the same thickness as the die pad 11. Furthermore, an external terminal 17C that is electrically connected to an external mounting substrate (not shown) is formed on the back surface of the thick portion 28. In addition, a plating portion 25 that improves adhesion to the bonding wire 22 is provided on the surface of the thick portion 28. Bonding wires 22 are connected to the surface of the thick portion 28 (plating portion 25).

  In addition, with the removal of the portion of the connection ring 14 excluding the thick portion 28, a resin recess 27 is formed in the region between the lead portions 12A and 12B and the die pad 11 on the back surface of the sealing resin 23. Is formed. Protrusions 27a corresponding to the recesses 14c are formed in the resin recess 27 between the adjacent thick portions 28.

  According to the present embodiment, when the semiconductor device 20A is manufactured, a part of the connection ring 14 is removed, and parts of the connection ring 14 that are not removed are individually separated, and the thick part 28 (terminal part) is formed. It is formed. Thus, by forming a large number of thick portions 28, the number of terminal portions (number of pins) connected to an external mounting substrate can be increased, and the density of the semiconductor device 20 can be further increased. Can be realized.

  In FIG. 7, the thick portion 28 left in the semiconductor device 20A is not necessarily used as an external terminal (terminal portion). For example, the thick portion 28 left in the semiconductor device 20A may serve to prevent deformation around the die pad 11 when an impact is applied to the semiconductor device 20A. Alternatively, the thick portion 28 may serve to improve the heat dissipation of the semiconductor device 20A by increasing the number of metal portions exposed on the back surface of the semiconductor device 20A.

  The method for manufacturing the lead frame 10 according to the present embodiment is substantially the same as the method for manufacturing the lead frame 10 according to the first embodiment (FIGS. 5A to 5F).

  Further, when the semiconductor device 20A according to the present embodiment is manufactured, when the part of the connection ring 14 is removed by etching from the back surface side of the lead frame 10 (see FIG. 6F), it corresponds to each recess 14c and its periphery. An opening 34a of the etching resist layer 34 is provided in the dot stripe in the region to be etched. And the surrounding area | region of each recessed part 14c among the connection rings 14 is selectively melt | dissolved and removed with the corrosive liquid which approached from the said opening part 34a.

  In this case, since the concave portion 14c is provided on the surface of the connection ring 14, the corrosive liquid entering from the opening 34a does not unnecessarily dissolve the thick portion 28 and the outer circumferential lead portions 12A and 12B, so that the connection ring 14, only the peripheral region of each recess 14 c can be appropriately removed. In this way, the thick portions 28 remain between the two recesses 14 c adjacent to each other in the connection ring 14. In addition, the method for manufacturing the semiconductor device 20A according to the present embodiment is substantially the same as the method for manufacturing the semiconductor device 20 according to the first embodiment (FIGS. 6A to 6G).

  FIG. 8 shows a semiconductor device 20B according to a modification of the present embodiment. In the semiconductor device 20B, among the plurality of thick portions (terminal portions) 28, 28A, some thick portions 28A are larger (the area is wider) than other thick portions 28. The thick wall portion 28 </ b> A has an elongated planar rectangular shape and extends along the side of the die pad 11. A plurality of bonding wires 22 are connected to the large thick portion 28A.

  In the present embodiment, a part of the thick portion 28A is formed larger than the other thick portions 28, and a plurality of bonding wires 22 are connected to the thick portion 28, whereby the large thick portion 28A is formed. For example, it can be used as a bus bar for adjusting an electric signal or a ground (GND) terminal. Thereby, the heat generation accompanying the increase in the number of terminals can be reduced, and a more reliable semiconductor device 20B can be obtained.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. 9 and 10 are diagrams showing a third embodiment of the present invention. The third embodiment shown in FIGS. 9 and 10 differs mainly in that a connection bar (lead connection portion) 64 is provided in place of the connection ring 14, and the other configuration is the first embodiment described above. This is substantially the same as the embodiment and the second embodiment. In FIG. 9 and FIG. 10, the same parts as those in the first embodiment and the second embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the lead frame 10C shown in FIG. 9, a connection bar 64 is provided between the die pad 11 and the plurality of lead portions 12A and 12B arranged in the Y direction (connected to the support leads 13 extending in the Y direction). Has been placed. On the other hand, the connection bar 64 is not disposed between the die pad 11 and the plurality of lead portions 12A and 12B arranged in the X direction (connected to the support leads 13 extending in the X direction).

  Each connection bar 64 is provided on the distal end side of the inner leads 51 of the lead portions 12A and 12B arranged along the Y direction. In FIG. 9, two connection bars 64 are provided per unit lead frame 10a, and each extend in parallel with the Y direction. However, the present invention is not limited to this, and one or more connection bars 64 may be provided per unit lead frame 10a. Further, the shape of the connection bar 64 is not limited to a linear shape, and may be a curved shape such as a substantially arc, a substantially V shape, a substantially L shape, or a substantially U shape.

  Inner leads 51 of the lead portions 12 </ b> A and 12 </ b> B are coupled to the outer peripheral edge portion (support lead 13 side peripheral portion) of each connection bar 64. Further, the connection bar 19 extends from each connection bar 64 toward the inside (on the die pad 11 side). In this case, each connection bar 64 is connected to all of the lead portions 12A and 12B arranged along the Y direction. However, the present invention is not limited to this, and the connection bars 64 are not limited to the lead portions 12A and 12B arranged along the Y direction. It may be connected to only a part.

  A plurality of recesses 64 c are formed on the surface of the connection bar 64 at intervals along the longitudinal direction of the connection bar 64. The recess 64c is formed by half etching and has a certain depth without penetrating in the thickness direction. Moreover, the recessed part 64c is formed in the width direction substantially center part of the connection bar 64, and the area | region which is not half-etched is formed in the width direction both sides of the recessed part 64c. Each recess 64 c is formed in the vicinity of the tip of each inner lead 51.

  A thick portion 66 is formed between the recesses 64c adjacent to each other. Each thick portion 66 is formed between the tips of the inner leads 51 adjacent to each other. The thick portion 66 is not half-etched and has the same thickness as the die pad 11 and the support lead 13. That is, the concave portions 64 c and the thick portions 66 are alternately arranged along the length direction of the connection bar 64.

  In addition, the configuration of the concave portion 64c and the thick portion 66 is substantially the same as the configuration of the concave portion 14c and the thick portion 28 shown in FIGS.

  The die pad 11 is supported by a connection bar 19 that is connected to each connection bar 64 by a plurality (two). The connecting bar 19 extends in the X direction and is thinned by half-etching from the back side.

  A semiconductor device 20C shown in FIG. 10 is manufactured using the lead frame 10C shown in FIG. In this semiconductor device 20C, the connection bar 64 is removed, and accordingly, the region between the die pad 11 and the lead portions 12A and 12B arranged along the Y direction on the back surface of the sealing resin 23. In addition, a resin recess 67 is formed. Two resin recesses 67 are provided for each semiconductor device 20 </ b> C, and extend in a straight line parallel to the sides of the die pad 11, generally corresponding to the shape of the connection bar 64. In the resin recess 67, a plurality of protrusions 67a made of a part of the sealing resin 23 protrude to the back side. Each of the protrusions 67a has a shape corresponding to the concave portion 64c of the connection bar 64 described above. The resin recess 67 may be filled with the same or different type of insulating resin as the sealing resin 23.

  According to the present embodiment, the connection bar 64 is not disposed between the die pad 11 and the lead portions 12A and 12B arranged along the X direction. For this reason, by extending the die pad 11 in the direction in which the connection bar 64 is not arranged (that is, the Y direction), the area can be increased. In this case, it becomes easy to mount a large semiconductor element 21 or a plurality of semiconductor elements 21 on the die pad 11.

  The lead frame 10C manufacturing method and the semiconductor device 20C manufacturing method according to the present embodiment are the same as the lead frame 10 manufacturing method (FIGS. 5A to 5F) according to the first embodiment and the semiconductor device 20 respectively. Is substantially the same as the manufacturing method (FIGS. 6A to 6G).

  A semiconductor device 20D shown in FIG. 11 shows a modification of the present embodiment. This semiconductor device 20D is manufactured from the lead frame 10C shown in FIG. 9, and the thick portion 66 is not completely removed but remains inside the semiconductor device 20D to form a terminal portion. Yes. The thick portions 66 are arranged at intervals from each other along all four sides (four sides parallel to the X direction or the Y direction in FIG. 11) around the die pad 11. The thick portions 66 are arranged at equal intervals between the die pad 11 and the lead portions 12A and 12B. Projection portions 67a corresponding to the recesses 64c are formed between the thick portions 66 adjacent to each other.

  In this case, in the connection bar 64 of the lead frame 10C, the peripheral region of each recess 64c is resin-sealed with the sealing resin 23 and then removed from the back side by etching. On the other hand, each thick part 66 is separated from the die pad 11, the lead parts 12A and 12B, and the other thick parts 66, and constitutes a terminal part electrically independently from these members. The thick portion 66 is not half-etched and has the same thickness as the die pad 11. Further, on the back surface of the thick portion 66, an external terminal 17C that is electrically connected to an external mounting substrate (not shown) is formed. Bonding wires 22 are connected to the surface of the thick portion 66, respectively.

  In addition, the configuration of the semiconductor device 20D illustrated in FIG. 11 is substantially the same as the configuration of the semiconductor device 20A illustrated in FIG.

10, 10A, 10C Lead frame 11 Die pad 12A, 12B Lead part 13 Support lead (support member)
14 Connection ring (lead connection)
14c Concave portion 15A Internal terminal 17A-17C External terminal 19 Connection bar 20, 20A-20D Semiconductor device 21 Semiconductor element 22 Bonding wire (connection member)
23 Sealing resin 24 Adhesive 25 Plating part 27 Resin recessed part 28 Thick part 51 Inner lead 52 Connection lead 53 Terminal part 64 Connection bar (lead connection part)

Claims (14)

A lead frame for a semiconductor device,
A die pad on which a semiconductor element is mounted;
A plurality of lead portions provided around the die pad, each including a terminal portion and an inner lead extending inward from the terminal portion;
A lead connection portion provided on the tip side of the inner lead,
A plurality of recesses are formed on the surface of the lead connection part at intervals along the length direction of the lead connection part,
A thick part is formed between the recesses adjacent to each other among the lead connection parts,
2. The lead frame according to claim 1, wherein the recess is formed in a central portion in the width direction of the lead connection portion, and regions that are not thinned are formed on both sides in the width direction of the recess.   The lead frame according to claim 1, wherein the lead connection portion is a connection ring surrounding the die pad.   3. The lead frame according to claim 1, wherein the plurality of recesses are arranged at equal intervals along a length direction of the lead connection portion.   The said thick part is provided with two or more, and one part thick part is larger than another thick part among the said some thick parts, The Claim 1 thru | or 3 characterized by the above-mentioned. Lead frame.   The lead frame according to any one of claims 1 to 4, wherein the lead connecting portion is supported by at least one of the inner leads.   6. The lead frame according to claim 1, wherein a connecting bar that connects the lead connecting portion and the die pad is provided, and the die pad is supported by the connecting bar. 7.   Each of the terminal portions of each lead portion has an external terminal, and the external terminals are alternately arranged in a staggered manner as viewed from the plane so as to be located inside and outside between the adjacent lead portions. The lead frame according to claim 1, wherein the lead frame is characterized in that:   The lead frame according to claim 1, wherein the inner lead is thinner than the terminal portion. A semiconductor device,
Die pad,
A plurality of lead portions provided around the die pad, each including a terminal portion and an inner lead extending inward from the terminal portion;
A semiconductor element mounted on the die pad;
A connecting member for electrically connecting the semiconductor element and the inner lead of each lead portion; a sealing resin for sealing the die pad; the plurality of lead portions; the semiconductor element; and the connecting member. With
Of the back surface of the sealing resin, a resin recess is formed between the lead portion and the die pad,
In the resin recess, a plurality of protrusions made of a part of the sealing resin protrude to the back surface side.   A plurality of thick portions are disposed between the die pad and the lead portion, and the plurality of thick portions are separated from the die pad and the lead portion and are spaced apart from each other. The semiconductor device according to claim 9.   The semiconductor device according to claim 10, wherein the semiconductor element and the thick portion are connected by a connection member.   A plurality of the thick portions are provided, and among the plurality of thick portions, some thick portions are larger than other thick portions, and a plurality of connection members are connected to the some thick portions. The semiconductor device according to claim 10, wherein the semiconductor device is a semiconductor device. A die pad on which a semiconductor element is mounted; a plurality of lead portions provided around the die pad; each including a terminal portion and an inner lead extending inwardly from the terminal portion; and a tip end side of the inner lead, In a method for manufacturing a lead frame, comprising a lead connecting portion provided on the leading end side of the lead,
Preparing a metal substrate;
Forming the die pad, the lead portion, and the lead connection portion on the metal substrate by etching the metal substrate,
A plurality of recesses are formed on the surface of the lead connection part at intervals along the length direction of the lead connection part,
A thick part is formed between the recesses adjacent to each other among the lead connection parts,
2. The lead frame manufacturing method according to claim 1, wherein the recess is formed in a central portion in the width direction of the lead connection portion, and regions that are not thinned are formed on both sides in the width direction of the recess. In a method for manufacturing a semiconductor device,
Preparing a lead frame according to any one of claims 1 to 8,
Mounting the semiconductor element on the die pad of the lead frame;
Electrically connecting the semiconductor element and the inner lead of each lead portion by a connecting member;
Sealing the die pad, the plurality of lead portions, the semiconductor element, and the connection member with a sealing resin;
And a step of removing at least a part of the lead connecting portion from the back side of the lead frame.

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