JP5512784B2 - Manufacturing method of semiconductor device - Google Patents

Description

  The present invention relates to a method of manufacturing a semiconductor device, and more particularly to a technique effective when applied to quality improvement of a non-lead type semiconductor device.

  In a conventional method for manufacturing a resin-encapsulated semiconductor device, an encapsulating sheet is brought into close contact with at least the bottom surface of a lead portion of a lead frame on which a semiconductor chip is mounted. This sealing sheet is a functional member that protects the sealing resin from entering the bottom surface of the lead portion and exposes the bottom surface of the lead portion as a standoff of a desired value. (For example, refer to Patent Document 1).

  Alternatively, the sealing sheet is a functional member that protects the sealing resin from entering the bottom surface of the lead portion and exposes the bottom surface of the lead portion and the bottom surface of the land electrode as a standoff of a desired value. (For example, refer to Patent Document 2).

JP 2001-127090 A (FIG. 6) Japanese Patent Laying-Open No. 2002-26223 (FIG. 6)

  In a non-lead type semiconductor device such as a QFN (Quad Flat Non-leaded Package), a part of each lead is arranged exposed at the peripheral edge of the back surface of the sealing body, and these are external terminals. Therefore, at the time of resin sealing, a sealing sheet is disposed on the mold surface of the resin molding die, and further, a lead frame that has been subjected to pellet bonding and wire bonding is disposed on the sealing sheet, and the back surface of each lead ( Resin molding is carried out by adhering a part) and the sealing sheet. Thereby, while preventing the sealing resin from adhering to the back surface of each lead, by injecting each lead into the sealing sheet at the time of injection of the sealing resin, after forming the sealing body, Each lead is slightly protruded from the back surface of the sealing body to secure a standoff.

  Note that the standoff is similarly formed on the suspension leads arranged at the corners of the sealing body. However, since the resin for molding resin remains on the surface (upper surface) side of the corner of the sealing body in a state of being connected to the corner, a cutting mold is formed on the surface of the corner when the suspension lead is cut. Therefore, it is very difficult to dispose the receiving part side of the sealing body. Therefore, when cutting the suspension leads, the back side of the corner of the sealing body is supported by the receiving part of the cutting die, and in this state, the sealing body A cutting punch is entered from the surface side to perform hanging lead cutting.

  At this time, since the standoff is also formed on the suspension lead, the cutting is performed by supporting the back side of the corner portion with a cutting die having a receiving portion (for example, a concave shape) avoiding the standoff portion. . However, due to the balance between the resin molding state around the stand-off and the receiving part of the cutting die, the sealing body around the stand-off of the hanging lead comes into contact with the receiving part of the cutting die when the hanging lead is cut. As a result, there is a problem that when the suspension lead is cut, the sealing body around the standoff of the suspension lead comes into contact with the receiving portion of the cutting mold and the resin chipping occurs.

  In addition, it is advantageous in reducing the manufacturing cost that the mark process for writing the company name, product code, etc. on the surface side of the sealing body is performed in a multiple lead frame state prior to the cutting of the suspension leads. For this reason, in the step of cutting the lead, multiple lead frames are arranged so that the back side of the sealing body faces upward, and in the marking step, the multiple lead frames are once turned upside down and sealed. The stop body 3 is disposed with the surface side facing upward. After the marking process, when the suspension leads are cut, a process of reversing the front and back of the multiple lead frames is required, which may reduce assembly throughput and increase manufacturing costs.

  In addition, when a semiconductor chip having the same thickness as that of another semiconductor device (for example, a thin QFP (Quad Flat Package), etc.) is mounted, a tab (chip mounting portion) or a suspension lead is imposed due to the restriction of the QFN package height. Is made thin by half-etching so as to be within the constraints of the package height, but the suspension leads are thin and long, making the suspension leads easier to move, and the resin during resin injection during resin sealing A phenomenon occurs in which the tab shifts (moves) in the direction of the back surface due to the fluid pressure.

  As a result, the tab is exposed on the back surface of the sealing body, or the sealing body is warped. As a result, a problem arises that the package height becomes out of specification or an appearance defect occurs.

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

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

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

  Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.

  That is, the present invention provides (a) a lead frame having a chip mounting portion, a plurality of suspension leads, and a plurality of leads on the mold surface of the lower mold of a resin mold having an upper mold and a lower mold. (B) a step of clamping the resin molding die by sandwiching the lead frame between the upper die and the lower die; and (c) sealing on the back side of the suspension lead. Forming the sealing body by resin-sealing a semiconductor chip so that a portion corresponding to a peripheral edge portion of the sealing body on the back surface of the suspension lead is covered with the sealing body. (D) cutting the plurality of leads by inserting a cutting punch from the back side of the sealing body; (e) marking the surface of the sealing body from the surface side; and (f) ) Enter the cutting punch from the surface side of the sealing body, and And cutting the number of suspension leads, and has a.

  In addition, the present invention includes (a) a chip mounting portion, leads arranged around the chip mounting portion, and suspension leads connected to the chip mounting portion, and the chip mounting portion and the suspension A lead is half-etched to prepare a lead frame provided with a protrusion, and (b) a semiconductor chip having a main surface on which a pad is disposed, and a back surface opposite to the main surface. A step of mounting on the chip mounting portion; (c) a step of bonding the lead and the pad with a conductive wire; and (d) an upper die, a lower die, and a gate portion for injecting a resin. And a step of preparing a resin molding die having a cavity formed between the upper die and the lower die, (e) after the step (c) and the step (d), the resin Placed on the lower mold of the mold And (f) after the step (e), the leads and the protrusions are brought into close contact with the sealing sheet, and the semiconductor chip is mounted. A step of clamping the upper die and the lower die while being positioned inside each of the cavities of the resin mold, and (g) after the step (f), the semiconductor chip and the lead A step of injecting an insulating resin into each of the cavities to form a sealing body for sealing a part of the chip mounting part, and (h) after the step (g), Cutting the lead and a part of the suspension lead in order to separate the sealing body, and after the step (h), the lead and a part of the protruding portion are formed on the semiconductor chip. The back surface of the sealing body, which is a surface facing the same direction as the back surface And al exposed, in which the back surface of the sealing body of the rear surface and the chip mounting portion and the suspension leads facing the same direction is covered with the insulating resin.

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

  The end of the suspension lead arranged on the outer periphery of the sealing body is covered with the sealing body on the back surface side, so that the suspension lead is not exposed at the corner of the back surface of the sealing body. The standoff by is not formed. Thereby, at the time of cutting the suspension lead, the corner portion on the back surface of the sealing body can be supported and cut by the flat portion having a large area of the cutting die, and the occurrence of resin chipping can be prevented. As a result, the quality of the semiconductor device can be improved.

It is a top view which shows an example of the structure of the semiconductor device of embodiment of this invention. FIG. 2 is a back view showing an example of the structure of the semiconductor device shown in FIG. 1. FIG. 2 is an enlarged partial perspective view showing a structure of a corner portion of the semiconductor device shown in FIG. 1. FIG. 2 is a plan view showing the structure of the semiconductor device shown in FIG. 1 through a sealing body. It is sectional drawing which shows the structure of the cross section cut | disconnected along the AA line shown in FIG. It is sectional drawing which shows the structure of the cross section cut | disconnected along the BB line shown in FIG. It is sectional drawing which shows the modification of the structure of the cross section cut | disconnected along the AA line shown in FIG. FIG. 8 is an enlarged partial plan view showing the structure shown in FIG. 7 through a sealing body. FIG. 2 is an enlarged partial back view showing an example of pin arrangement on the back surface of a corner portion of the semiconductor device shown in FIG. 1. It is a back view which shows the structure of the semiconductor device of the modification of embodiment of this invention. FIG. 2 is an assembly flow diagram illustrating an example of a manufacturing method of the semiconductor device illustrated in FIG. 1. FIG. 12 is a partial cross-sectional view showing an example of a resin injection method when using a plate thickness gate in the molding step of the method for manufacturing the semiconductor device shown in FIG. 11. FIG. 12 is a partial cross-sectional view illustrating an example of a resin injection method when a normal gate is used in a molding process of the semiconductor device manufacturing method illustrated in FIG. 11. FIG. 13 is an enlarged partial plan view showing an example of the positional relationship between the gate and the lead when the plate thickness gate shown in FIG. 12 is used. FIG. 14 is an enlarged partial plan view showing an example of the positional relationship between the gate and the lead when the normal gate shown in FIG. 13 is used. FIG. 16 is a partially enlarged plan view showing a structure of a corner portion of the frame shown in FIG. 15. FIG. 12 is a partially enlarged cross-sectional view and a partially enlarged side view showing an example of a processing state in each process from lead cutting to singulation in the method for manufacturing the semiconductor device shown in FIG. 11. FIG. 2 is an enlarged partial back view showing an example of pin arrangement on the back surface of a corner portion of the semiconductor device shown in FIG. 1. FIG. 14 is an enlarged partial perspective view showing a structure of a corner portion of the semiconductor device when the normal gate shown in FIG. 13 is used.

  In the following embodiments, the description of the same or similar parts will not be repeated in principle unless particularly necessary.

  Further, in the following embodiment, when it is necessary for the sake of convenience, the description will be divided into a plurality of sections or embodiments, but they are not irrelevant to each other unless otherwise specified. The other part or all of the modifications, details, supplementary explanations, and the like are related.

  Also, in the following embodiments, when referring to the number of elements (including the number, numerical value, quantity, range, etc.), particularly when clearly indicated and when clearly limited to a specific number in principle, etc. Except, it is not limited to the specific number, and it may be more or less than the specific number.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiments, and the repetitive description thereof will be omitted.

(Embodiment)
1 is a plan view showing an example of the structure of a semiconductor device according to an embodiment of the present invention, FIG. 2 is a back view showing an example of the structure of the semiconductor device shown in FIG. 1, and FIG. 3 is a corner of the semiconductor device shown in FIG. FIG. 4 is a plan view showing the structure of the semiconductor device shown in FIG. 1 through a sealing body, and FIG. 5 is a cross-sectional view taken along the line AA shown in FIG. FIG. 6 is a cross-sectional view showing the structure of a cross section taken along the line BB shown in FIG. 4, and FIG. 7 is a cross-sectional view taken along the line AA shown in FIG. FIG. 8 is an enlarged partial plan view showing the structure shown in FIG. 7 through the sealing body, and FIG. 9 is an example of pin arrangement on the back surface of the corner of the semiconductor device shown in FIG. FIG. 10 is a rear view showing the structure of a semiconductor device according to a modification of the embodiment of the present invention, and FIG. FIG. 12 is a partial cross-sectional view showing an example of a resin injection method when using a thickness gate in the molding process of the semiconductor device manufacturing method shown in FIG. 11, and FIG. 13 is shown in FIG. FIG. 14 is a partial cross-sectional view showing an example of a resin injection method when a normal gate is used in the molding process of the semiconductor device manufacturing method, and FIG. FIG. 15 is an enlarged partial plan view showing an example of the positional relationship between the gate and the lead when the normal gate shown in FIG. 13 is used, and FIG. 16 is a partial enlarged plan view showing the structure of the corner of the frame shown in FIG. 17 is a partially enlarged cross-sectional view and a partially enlarged side view showing an example of a processing state in each process from lead cutting to singulation of the semiconductor device manufacturing method shown in FIG. 11, and FIG. 18 is shown in FIG. Corners enlarged partial rear view showing an example of the pin arrangement of the back surface of the semiconductor device, FIG. 19 is an enlarged partial perspective view showing the structure of a corner portion of the semiconductor device during normal gate used as shown in FIG. 13.

  The semiconductor device of the present embodiment shown in FIGS. 1 to 6 is of a small non-lead type in which a part of each of the plurality of leads 1a is exposed and arranged at the peripheral edge of the back surface 3a of the sealing body 3. In the present embodiment, QFN 5 will be described as an example of the semiconductor device.

  The structure of the QFN 5 will be described. A semiconductor chip 2 having a semiconductor element and a plurality of pads (electrodes) 2a on its main surface 2b, a sealing body 3 for resin-sealing the semiconductor chip 2, and an inside of the sealing body 3 A tab 1b which is a chip mounting portion connected to the semiconductor chip 2 and a suspension lead 1e which supports the tab 1b by connecting the corners of the tab 1b, and each connected surface (part) 1g are sealed. A plurality of leads 1a exposed at the peripheral edge of the back surface 3a of the stationary body 3 and arranged side by side with the peripheral edge, a plurality of pads 2a of the semiconductor chip 2, and the plurality of leads 1a corresponding thereto The ends of the suspension leads 1e disposed on the outer periphery of the sealing body 3 are covered with the sealing body 3 on the back surface 3a side of the sealing body 3. It has been broken.

  That is, as shown in FIG. 2, the end portion of the suspension lead 1 e is not exposed at the corner of the back surface 3 a of the sealing body 3, but is embedded in the sealing body 3. However, at the corner portion of the sealing body 3, the cut surface 1 h of the suspension lead 1 e is exposed on the side surface of the corner portion of the sealing body 3 as shown in FIG. 3.

  In this way, the end portion of the suspension lead 1e disposed on the outer peripheral portion of the sealing body 3 is covered with the sealing body 3 on the back surface 1f side and is not exposed at the corner of the back surface 3a of the sealing body 3. For this reason, the standoff of the suspension lead 1e by resin molding (protrusion of the lead portion from the back surface 3a of the sealing body 3) is not formed. Thereby, at the time of cutting the suspension lead, as shown in FIG. 17, the corner portion of the back surface 3a of the sealing body 3 is formed by the flat portion 10c having an area wider than 1 m of the suspension lead 1e of the receiving portion 10a of the cutting die 10. It is possible to support and cut, and as a result, it is possible to prevent the occurrence of resin chipping.

  Further, in the QFN 5 of the present embodiment, the tab 1b and the suspension lead 1e that supports the tab 1b are thinly formed by half-etching or the like, and are embedded inside the sealing body 3 as shown in FIG. Yes. However, in each of the tab 1b and the suspension lead 1e, a protrusion 1j is provided on a part of each of the back surfaces 1d and 1f, and the protrusion 1j is formed on the back surface 3a of the sealing body 3 as shown in FIGS. Exposed.

  The processing method for thinning the tab 1b and the suspension lead 1e is not limited to the half etching processing, and a processing method other than half etching such as coining processing may be adopted. In the QFN 5 of the present embodiment, the tabs 1b and the suspension leads 1e are half-etched except for the regions corresponding to the protruding portions 1j at the manufacturing stage of the lead frame 1 (see FIG. 12). The region that is formed and not half-etched is the protruding portion 1j.

  As described above, the protrusions 1j are provided on the back surfaces 1d and 1f of the tab 1b and the suspension lead 1e, so that the tab 1b and the suspension lead 1e are pushed in the back direction by the resin flow pressure when the resin is injected during resin sealing. However, as shown in FIG. 12, the protruding portion 1j contacts the film sheet (sealing sheet) 8 on the mold surface 9d of the resin molding die 9, whereby the tab 1b and the suspension lead 1e. Is supported by the projecting portion 1j and does not move in the back surface direction, so that the shift (movement) of the tab 1b in the back surface direction due to the resin flow pressure can be prevented.

  The protrusion 1j supports the tab 1b at the time of resin injection and prevents the tab 1b from shifting to the back surface side. Therefore, as shown in FIGS. 5 and 6, it is provided at the center of the back surface 1d of the tab 1b. It is preferable that the plurality of projecting portions 1j may be provided by providing them around the periphery. However, it is preferable not to arrange the protruding portion 1j as much as possible in order to route the wiring below the back surface 1d of the tab 1b. At this time, for the tab 1b, a tab (large tab) 1b in which the area of the tab 1b is larger than the area of the semiconductor chip 2 or a tab (small tab) in which the area of the tab 1b is smaller than the area of the semiconductor chip 2 is used. It does not matter whether 1b is used. However, by making the area of the tab 1b smaller than the area of the semiconductor chip 2, peeling at the time of solder reflow is prevented and stress at the temperature cycle is reduced, so that the mounting reliability is improved.

  Further, in the suspension lead 1e, for example, as shown in the modified examples of FIGS. 7 and 8, it is preferable that the protrusion 1j is provided at a location corresponding to the corner of the semiconductor chip 2 on the back surface 1f. In addition to this, when the protrusion 1j is provided at the center of the back surface 1d of the tab 1b, the protrusion 1j is exposed at five locations on the back surface 3a of the sealing body 3, as shown in FIG. become.

  Thereby, the location of the tab 1b can be stabilized, and the tab 1b itself can be prevented from being inclined.

  Further, when the number of pins increases due to the increase in the number of pins, the pitch between the pins tends to decrease. Therefore, the suspension leads 1e are not exposed at the corners of the back surface 3a of the sealing body 3. Is also preferable. For example, in the case of a QFN5 of 64 pins with a package size of 9 mm × 9 mm, as shown in FIG. 9, the inter-pin pitch is A, the inter-pin distance is B, and the connected portion that is the exposed portion of the lead 1a If the length of the surface 1g is C, each dimension is preferably determined so that A> B> C. In this case as well, the book in which the suspension leads 1e are embedded in the inside of the sealing body 3 at the corners. It is effective to adopt the QFN structure of the embodiment. Further, as shown in FIG. 18, as the package is downsized and the pitch is reduced by increasing the number of pins, the inter-pin distance B at the corner also becomes shorter. Therefore, the corner lead 1a has a corner on the side of the suspension lead 1e. Is preferably provided with a taper (chamfering) 1n.

  Further, as shown in the modification of FIG. 10, in the QFN 5 of the present embodiment, the tab 1 b and the suspension lead 1 e do not necessarily have to be provided with the protruding portion 1 j, and the tab 1 b on the back surface 3 a side of the sealing body 3. Alternatively, the suspension lead 1e may not be exposed at all. That is, the tab 1b and the suspension lead 1e are formed by thinly etching back surfaces 1d and 1f of the tab 1b and the suspension lead 1e, and the projecting portion 1j is not provided. Since the suspension lead 1e is not exposed at the corner of 3a, the stand-off of the suspension lead 1e by resin molding is not formed, and as a result, the occurrence of resin chipping when the suspension lead is cut can be prevented.

  As described above, in the QFN 5 of the present embodiment, the end portion of the suspension lead 1e that is disposed on the outer peripheral portion of the sealing body 3 is covered with the sealing body 3 on the back surface 1f side. The suspension leads 1e are not exposed at the corners of the back surface 3a of the body 3, and therefore no standoff is formed by the suspension leads 1e. Thereby, at the time of cutting the suspension lead, as shown in FIG. 17, the corner portion of the back surface 3a of the sealing body 3 is formed by the flat portion 10c having an area wider than 1 m of the suspension lead 1e of the receiving portion 10a of the cutting die 10. Since it can be supported and cut, the occurrence of resin chipping can be prevented.

  As a result, the quality of QFN 5 can be improved.

  In addition, since the suspension leads 1e are not exposed at the corners of the back surface 3a of the sealing body 3, wiring is routed to a region corresponding to the corners of the back surface 3a of the sealing body 3 on the mounting substrate on which the QFN 5 is mounted. Thus, the mountability of the QFN 5 can be improved.

  In addition, since the protrusion 1j is provided on at least one or both of the back surface 1d of the tab 1b and the back surface 1f of the suspension lead 1e, the tab 1b and the suspension lead 1e are caused by resin flow pressure during resin injection during resin sealing. 12 is pushed in the reverse direction, as shown in FIG. 12, the projecting portion 1j contacts the film sheet 8 on the mold surface 9d of the resin mold 9 to support the tab 1b and the suspension lead 1e.

  As a result, the tab 1b and the suspension lead 1e are supported by the protruding portion 1j and do not move in the rear surface direction, so that the shift (movement) of the tab 1b in the rear surface direction due to the resin flow pressure can be prevented. Therefore, the exposure of the tab 1b to the back surface 1d and the warping of the sealing body 3 can be prevented, and the quality of the QFN 5 is improved by preventing the height of the QFN 5 from being out of specification or causing appearance defects. Can be achieved.

  As shown in FIG. 12, the semiconductor chip 2 is fixed on the chip support surface 1c of the tab 1b by a die bond material (for example, silver paste) 6, and the back surface 2c of the semiconductor chip 2 and the chip of the tab 1b. The support surface 1c is connected.

  Furthermore, as shown in FIG. 6, each lead 1a arranged alongside the peripheral edge of the back surface 3a of the sealing portion 3 of the QFN 5 has a thick portion 1i, and a part of them is a connected surface. 1 g is exposed on the back surface 3 a of the sealing body 3. On this connected surface 1g, solder plating or palladium plating is formed as exterior plating.

  The tab 1b, the suspension lead 1e, and each lead 1a are formed of a thin plate material such as a copper alloy, for example.

  Furthermore, the semiconductor chip 2 has a back grind (back surface polishing) corresponding to the thinning of the QFN 5, for example, and the chip thickness is, for example, 0.2 mm (200 μm).

  Moreover, the wire 4 which is a metal fine wire which connects the pad 2a of the semiconductor chip 2 and the corresponding lead 1a is, for example, a gold wire.

  Moreover, the sealing body 3 is formed by resin sealing by a molding method, and the sealing resin used at that time is, for example, a thermosetting epoxy resin.

  Next, a method for manufacturing QFN 5 (semiconductor device) of the present embodiment will be described using the assembly flow shown in FIG.

  First, when the QFN 5 is compatible with thinning, the semiconductor wafer is back-polished by back grinding shown in step S1 to form a thin semiconductor wafer. For example, the back surface is polished so that the thickness becomes 200 μm. However, the backside polishing of the semiconductor wafer for thinning is not necessarily performed.

  On the other hand, a tab 1b on which the semiconductor chip 2 can be mounted, a plurality of leads 1a arranged around the tab 1b, and a suspension lead 1e that supports the tab 1b, and the back surfaces 1d of the tab 1b and the suspension lead 1e, respectively. A lead frame 1 is prepared in which if is thinly formed by half-etching or the like, and protrusions 1j are provided on the back surfaces 1d and 1f of the tab 1b and the suspension lead 1e, respectively.

  Thereafter, die bonding shown in step S2 is performed. Here, the semiconductor chip 2 is fixed to the chip support surface 1c of the tab 1b, which is the chip mounting portion of the lead frame 1, via the die bonding material 6.

  Thereafter, wire bonding shown in step S3 is performed. Here, the pads 2a of the semiconductor chip 2 and the corresponding leads 1a are connected by wires (metal thin wires) 4 such as gold wires.

  Thereafter, resin sealing (molding) shown in step S4 is performed. In that case, first, as shown in FIG. 12, the film sheet 8 which is a sealing sheet is disposed on the mold surface 9d of the lower mold 9b of the resin mold 9. Further, after the lead frame 1 is disposed on the film sheet 8, the resin molding die 9 is clamped (clamped) so that the connected surfaces 1 g of the leads 1 a are in close contact with the film sheet 8.

  Subsequently, a sealing resin is wrapped around the back surfaces 1d and 1f of the tab 1b and the suspension lead 1e to correspond to the peripheral portion of the sealing body 3 of the back surface 1d of the tab 1b and the back surface 1f of the suspension lead 1e. The sealing body 3 is formed by resin-sealing the semiconductor chip 2 and the plurality of wires 4 so that the back surface 1f side of the end portion of the suspended lead 1e is covered with the sealing body 3 (sealing resin).

  In addition, when injecting the sealing resin into the cavity 9c of the upper mold 9a of the resin molding die 9, as shown in FIG. 14, the area where the half etching process is performed outside the end of the suspension lead 1e is performed. In a state where a portion of P (hatched portion region P shown in FIG. 14) where the half etching process is not performed further is pressed by the gate portion 9e of the resin molding die 9, the runner 9f and the gate portion 9e of FIG. The resin is sealed by injecting a sealing resin into the cavity 9c from the gap 1k corresponding to the thickness of the leads on both sides of the suspension lead 1e shown in FIG. 14 by the resin injection path 7 over the cavity 9c.

  At this time, since the suspension lead 1e is thinly formed by half-etching, the gate opening is widened, and the fluidity of the sealing resin flowing into the cavity 9c can be improved.

  Furthermore, as shown in FIG. 12, the protrusion 1j is provided on the back surface 1d of the tab 1b and the back surface 1f of the suspension lead 1e, so that the tab 1b and the suspension lead 1e are moved in the back direction by resin flow pressure during resin injection. Even if pressed, the projecting portion 1j contacts the film sheet 8 on the mold surface 9d of the lower mold 9b of the resin molding die 9, thereby supporting the tab 1b and the suspension lead 1e by the projecting portion 1j. Since it does not move in the direction, it is possible to prevent the tab 1b from being shifted in the reverse direction due to the resin flow pressure.

  As a result, the exposure of the tab 1b to the back surface 1d and the warping of the sealing body 3 can be prevented, and the quality of the QFN 5 can be prevented by preventing the height of the QFN 5 from being out of specification or causing appearance defects. Improvements can be made.

  13 and FIG. 15, the gate port may be arranged on the upper side of the suspension lead 1e to form the resin injection path 7 shown in FIG. The fluidity of the sealing resin flowing into 9c can be improved. In the case of the resin injection method using this normal gate, as shown in FIG. 19, the resin burr 3b is formed on the surface side of the suspension lead 1e after the resin molding is completed. Therefore, at the time of cutting the suspension lead 1e, the back surface side of the corner portion of the sealing body 3 is supported by the molding die 10, and the cutting punch 10d is entered from the front surface side (upper side) of the sealing body 3 in this state and suspended. The lead 1e is cut.

  Accordingly, the molding die 10 having the receiving portion 10a having a flat surface (flat portion 10c) is formed in the receiving portion 10a of the molding die 10 without forming a concave shape (groove) for escaping the resin burr 3b. The suspension lead 1e can be cut using this (see FIG. 17).

  FIG. 16 shows the positional relationship between the outer peripheral line of the sealing body 3 and the half etching region P of the suspension lead 1e (the hatched portion region P shown in FIGS. 15 and 16) when sealing is performed by this resin injection method. Since the half-etched region P of the suspension lead 1e extends over the inside and outside of the corner of the sealing body 3, the back surface 1f side of the end portion of the suspension lead 1e is the sealing body 3 (for sealing). A structure covered with resin can be realized.

  Thereby, since the suspension lead 1e is not exposed at the corner of the back surface 3a of the sealing body 3, a standoff by the suspension lead 1e is not formed.

  However, since the plurality of leads 1a other than the suspension leads 1e are molded with the surface 1g to be in close contact with the film sheet 8 and slightly indented into the film sheet 8, the resin leads are sealed. The connected surface 1g of each lead 1a can be projected from the back surface 3a of the sealing body 3, and a standoff can be formed on each lead 1a.

  After the resin sealing is completed, lead cutting shown in step S5 of FIG. 11 is performed.

  Here, as shown in step S5 of FIG. 17, the back surface 3a side of the sealing body 3 is directed upward, and the receiving portion 10a and the pressing portion 10b of the cutting die 10 are fixed with the cutting margin 1m sandwiched therebetween. In this state, the cutting punch 10d is entered from the back surface 3a side (upper side) of the sealing body 3 to cut the plurality of leads 1a.

  That is, each lead 1a is preferably formed with a standoff on the back surface 3a side of the sealing body 3, and lead burrs generated on the lead cutting surface are preferably formed on the surface side of each lead 1a. Sometimes the front surface side is received instead of the back surface side of each lead 1a, and in this state, the cutting punch 10d is entered from the back surface side (upper side) of the lead 1a to perform cutting.

  Thereby, the lead burrs formed on the lead cut surface can be formed toward the surface side of each lead 1a, and the solder connection area when the QFN 5 is mounted on a mounting substrate or the like can be increased.

  Thereafter, the process proceeds to a mark process shown in step S6 of FIG. Here, as shown in step S6 of FIG. 17, first, the front and back of the sealing body 3 are reversed, and the front surface side of the sealing body 3 is disposed upward. In this state, desired marking is performed on the surface of the sealing body 3 from the surface side of the sealing body 3 using a laser 11 or the like.

  Thereafter, the process proceeds to the individualizing step shown in step S7 of FIG. Here, as shown in step S7 of FIG. 17, the state in which the surface side of the sealing body 3 is directed upward is maintained, and in this state, the cutting punch 10d is entered from the surface side of the sealing body 3 to suspend the leads. 1e is cut and separated into pieces. That is, in the QFN 5 of the present embodiment, since the standoff is not formed on the suspension lead 1e, when the suspension lead is cut, the peripheral portion of the back surface 3a of the sealing body 3 corresponding to the end of the suspension lead 1e is The cutting die 10 can be supported by the flat portion 10c having an area sufficiently larger than the cutting margin 1m of the suspension lead 1e of the receiving portion 10a of the cutting die 10, and the suspension lead can be cut in this state.

  As a result, the reversing process performed when using the thickness gate can be omitted, and the occurrence of resin chipping when cutting the suspension leads when using the normal gate can be prevented, and the quality of the QFN 5 can be improved.

  Thus, in the assembly of the QFN 5 of the present embodiment, in the marking process and the singulation (hanging lead cutting) process, the process can be performed with the surface side of the sealing body 3 facing upward, Moreover, since the inversion process which arrange | positions the back surface side of the sealing body 3 toward the upper direction can be abbreviate | omitted, it is also possible to use the consistent processing apparatus which can perform the process of both marking and suspension lead cutting | disconnection. As a result, the manufacturing cost can be reduced.

  Note that the hanging lead cutting can be performed by causing the cutting punch 10d to enter from the surface side of the sealing body 3 irrespective of the presence or absence of the marking process. Even if the cutting punch 10d is inserted from the back surface 3a side and cutting is performed, the effect of reducing resin chipping can be obtained. Therefore, when the mark process is not performed or when the mark process is performed after the QFN 5 is separated, the lead cutting and suspended lead cutting processes are performed with the back surface 3a side of the sealing body 3 facing upward. You may continue.

  After completion of singulation by cutting the suspension leads, the storage shown in step S8 in FIG. 11 is performed to store the QFN 5 in a tray (or magazine) or the like. Furthermore, after performing the marking process first, the lead cutting and the suspended lead cutting processes may be performed, and after completion of singulation, the storage shown in step S8 of FIG. 11 may be performed. However, if the mark process is performed before lead cutting, there is a risk that the mark may be damaged or the mark may disappear due to cleaning after lead cutting.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiments of the invention. However, the present invention is not limited to the embodiments of the invention, and various modifications can be made without departing from the scope of the invention. It goes without saying that it is possible.

  For example, in the above embodiment, the QFN 5 has been described as an example of the semiconductor device. However, the semiconductor device is a non-lead having a structure in which the end of the suspension lead 1e is not exposed at least at the corner of the back surface 3a of the sealing body 3. As long as it is of a type, it may be a semiconductor device other than QFN.

  The present invention is suitable for an electronic device manufacturing technique.

1 Lead frame 1a Lead 1b Tab (chip mounting part)
1c Chip support surface 1d Back surface 1e Hanging lead 1f Back surface 1g Connected surface (part)
1h Cut surface 1i Thick part 1j Protruding part 1k Gap 1m Cutting margin 1n Taper (Chamfer)
2 Semiconductor chip 2a Pad (electrode)
2b Main surface 2c Back surface 3 Sealed body 3a Back surface 3b Resin burr 4 Wire (fine metal wire)
5 QFN (semiconductor device)
6 Die bond material 7 Resin injection route 8 Film sheet (sealing sheet)
9 resin molding die 9a upper die 9b lower die 9c cavity 9d die surface 9e gate portion 9f runner 10 cutting die 10a receiving portion 10b holding portion 10c flat portion 10d cutting punch 11 laser

Claims (16)

(A) A lead frame having a chip mounting portion on which a semiconductor chip is mounted, a suspension lead having a first portion connected to the chip mounting portion, and a plurality of leads arranged around the chip mounting portion is prepared. a process, the thickness of the first part before Symbol hanging lead, a step of preparing a second portion of the lead frame by Ri have thin thickness located outside than the first portion,
(B) The lead frame is disposed on the resin molding die so that the semiconductor chip is positioned in a cavity of the upper die of a resin molding die having an upper die and a lower die, and the first of the suspension leads is arranged . Pressing a part with the part of the upper mold of the resin molding die and pressing the second part of the suspension lead with the part of the upper mold and the lower mold of the resin molding mold ; ,
(C) after the step (b), Ri by the injecting resin into the cavity of the resin molding die, a step of forming a sealing body in which the semiconductor chip is resin-sealed, said suspension leads, the plurality of most adjacent leads to the suspension leads of the lead, the resin from between the injected, the back surface of the first portion of the suspension lead the sealing body covers and, Forming the sealing body such that the back surfaces of the leads are exposed from the sealing body. In the manufacturing method of the semiconductor device according to claim 1,
Wherein step (c), the resin molding die wherein the upper die of the lower die, injecting the suspension lead, and the resin from the gap surrounded by the lead most adjacent to the suspension lead. In the manufacturing method of the semiconductor device according to claim 2,
The gap is formed on both sides of the suspension lead. In the manufacturing method of the semiconductor device according to claim 2,
The height of the gap is the same as the thickness of the thickest portion of the leads closest to the suspension lead. In the manufacturing method of the semiconductor device according to claim 1,
Wherein step (c), the resin was flow around the back side of the first portion of the suspension lead is injected into the cavity of the resin molding die. In the manufacturing method of the semiconductor device according to claim 1,
In the step (b), the back surface of each of the plurality of leads is in close contact with the film sheet disposed on the lower mold surface of the resin mold. The plurality of leads are pressed by the upper mold and the lower mold. In the manufacturing method of the semiconductor device according to claim 6,
After the step (c), the back of each of the plurality of leads projects from the back surface of the sealing body. In the manufacturing method of the semiconductor device according to claim 1,
The chip mounting portion has a third portion and a fourth portion whose thickness is greater than the thickness of the third portion,
In the step (b), the fourth part of the chip mounting portion is formed on the resin molding die so as to come into contact with a film sheet disposed on the die surface of the lower die of the resin molding die. The plurality of leads are pressed by the upper mold and the lower mold. In the manufacturing method of the semiconductor device according to claim 8 ,
After the step (c), the fourth portion of the chip mounting portion is exposed from the back surface of the sealing body. In the manufacturing method of the semiconductor device according to claim 1,
(D) After the step (c), in a state where a part of the sealing body formed on the back surface of the first portion of each of the plurality of suspension leads is supported by a cutting die, the plurality of suspension The method further includes a step of cutting the lead. In the manufacturing method of the semiconductor device according to claim 10,
In step (d), the area of the portion for supporting a portion of the sealing body of the cutting die, said suspension cutting Shiroyo Li Guang physician lead. In the manufacturing method of the semiconductor device according to claim 10,
Between the step (c) and the step (d), a cutting punch is inserted from the back side of the sealing body to cut the plurality of leads. In the manufacturing method of the semiconductor device according to claim 12,
In the step of cutting the plurality of leads, a cutting punch is entered from the surface side of the sealing body to cut the plurality of suspension leads. In the manufacturing method of the semiconductor device according to claim 1,
The back surface of the first portion of the suspension lead is half-etched. In the manufacturing method of the semiconductor device according to claim 1,
Between the step (a) and the step (b), there is a step of electrically connecting a plurality of pads provided on the semiconductor chip and the plurality of leads respectively with a plurality of wires. In the manufacturing method of the semiconductor device according to claim 1,
In the step (b), the part of the upper mold of the resin molding die presses the surfaces of the first and second parts of the suspension lead.

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