JP2003017643A - Semiconductor device manufacturing method and cutting device - Google Patents

Abstract

(57) [Summary] [Problem] To prevent resin burrs from falling off. SOLUTION: A step of molding a part of a lead frame with an insulating resin to form a sealing body, and punching a dam bar connecting a plurality of leads projecting from a side surface of the sealing body over a predetermined length. And a step of cutting and removing resin burrs between the leads by the punch with the die, and a die for supporting a lead portion between the dam bar and the sealing body. The dam bar is cut by setting the side edge of the portion inside the side edge of the lead.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device manufacturing technique, and more particularly to a technique effectively applied to a dam bar cutting technique after transfer molding in the production of a resin-sealed semiconductor device.

[0002]

2. Description of the Related Art In a semiconductor device such as an IC (integrated circuit device), a structure is known in which a semiconductor chip, a wire and the like are sealed with a resin sealing body (package). A lead frame is used in the manufacture of the resin-sealed semiconductor device. After the semiconductor chip is fixed and the wire bonding is completed, the lead frame is molded by a transfer molding device. As a result, the semiconductor chip, wires, etc. are covered with a sealing body made of resin (resin).

After that, resin burrs and unnecessary resin portions protruding from the package are removed, dam bars (tie bars) for connecting the leads are cut and removed, and tab suspension leads for supporting the tabs to which the semiconductor chip is fixed are cut.
Lead cutting, lead molding, etc. are performed to manufacture a desired semiconductor device.

"VLSI packaging technology (below)" issued by Nikkei BP, issued May 15, 1993, P41 to P50 describes deburring, exterior, and T / F (trimming and forming). There is. According to this document, when molding resin is sealed, the space surrounded by the outer lead and the dam bar (dam) is filled with resin for the thickness of the lead frame, and this resin portion is referred to as a burr (resin burr). It is stated that it is called.

[0005]

In manufacturing a resin-encapsulated semiconductor device, solder molding is performed after transfer molding, and then dam bar cutting and cut molding are performed to manufacture a semiconductor device having a predetermined lead structure.

In this case, the dam bar is cut by cutting the dam bar 2 of the lead frame 1 on the die 3 with a punch 4 as shown in FIG. That is, to be more specific, the dam bar 2 is formed by the receiving blade 5 and the punch 4 which project from the die block 10 of the die 3 at a predetermined interval.
Disconnect. The receiving blade 5 extends along the lead 7, and both side edges of the receiving blade 5 are positioned outside the lead 7 to support the lead 7 over the entire width thereof. The punch 4 has a rectangular pattern intersecting with the dam bar 2 and is separated from the sealing body 6 so as not to contact the sealing body (package) 6. As a result, the resin burrs (resin burrs) 11 formed in the region surrounded by the adjacent leads 7 and the dam bar 2 connecting the adjacent leads 7 are cut in the shape of the punch 4, and as shown in FIG. The sealing body 6 and the leads 7 are left in a V shape (residual resin burr 12).

However, the residual resin burr 12 is liable to be cracked or chipped at various portions due to the impact during shearing. That is, since the residual resin burr 12 is integrated with the sealing body 6, a crack or the like due to peeling is unlikely to occur between the residual resin burr 12 and the sealing body 6. However, at the interface between the residual resin burr 12 and the lead 7, since the lead 7 is made of metal, the adhesiveness is low, and peeling or chipping is likely to occur between the residual resin burr 12 and the lead 7.

As a result, the resin burr remaining due to the vibration or shock applied thereafter easily comes off from the lead 7. The resin burr that has fallen off, that is, the resin lump, causes the following problems during the processing of subsequent products. That is, when the resin burr drops off and adheres to the lead frame (lead) or the package, when the lead frame such as a cutting die is clamped, a step is created due to the interposition of the adhered resin block, and a large force is exerted on the package portion at the base of the lead. It may act to cause cracks or chips in the package. Further, the stress may reach the inside of the package, and cracks or breaks may occur in the semiconductor chip. These phenomena cause defective products.

Further, when the resin block adheres to the lead portion of the lead frame, the surface of the lead is dented or bent when the die is clamped. The dents and bends in the lead lead to poor appearance. In addition, if resin blocks adhere to the transfer rails inside the mold or the transfer rails of the device, it may cause transfer failures, resulting in damage to the mold or lead frame (semiconductor device), which may lead to manufacturing defects such as unavailability or reduced yield. cause.

An object of the present invention is to provide a technique for manufacturing a semiconductor device in which resin burr is less likely to fall off. Another object of the present invention is to improve the quality of semiconductor devices and reduce manufacturing costs. The above and other objects and novel features of the present invention will be apparent from the description of the present specification and the accompanying drawings.

[0011]

The outline of the representative ones of the inventions disclosed in the present application will be briefly described as follows.

(1) A step of molding a part of the lead frame with an insulating resin to form a sealing body, and a dam bar connecting a plurality of leads protruding from the side surface of the sealing body for a predetermined length. A method of manufacturing a semiconductor device, the method including: cutting and removing with a punch and a die, and also cutting and removing resin burrs between the leads by the punch,
The dam bar is cut with the side edge of the die portion supporting the lead portion between the dam bar and the sealing body positioned inside the side edge of the lead.

In the method of manufacturing such a semiconductor device, the following cutting device is used. The cutting device is a semiconductor device for cutting a dam bar connecting a plurality of leads juxtaposed from a side surface of the sealing body of a lead frame partially having a sealing body by a cutting die die and a punch cutting operation. In the cutting device for manufacturing, the die portion supporting the lead portion between the dam bar and the sealing body has a structure in which the side edge is located inside the side edge of the lead.

According to the above-mentioned means (1), (a) in the cutting die for cutting the dam bar, the die portion supporting the lead portion between the dam bar and the sealing body has a side edge of the lead. The structure is located inside the side edge.
For this reason, when cutting the resin burr between the leads with a punch to cut it, the resin burr adhered to the side surface of the lead is not supported by the die part, so it peels off at the interface with the side surface of the lead and falls. It is possible to suppress the occurrence of residual resin burr that adheres to the leads. Therefore, it is possible to prevent cracking and chipping of the package and the semiconductor chip, lead bending, dents on the surface of the lead, unavailability of production, and reduction in yield due to the resin mass that falls off. As a result, a semiconductor device with excellent quality can be manufactured at low cost.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all the drawings for explaining the embodiments of the invention, components having the same function are designated by the same reference numeral, and the repeated description thereof will be omitted.

(First Embodiment) In the first embodiment, the SOP
An example in which the present invention is applied to cutting a dam bar after molding in manufacturing a (Small Outline Package) type resin-sealed semiconductor device will be described.

FIG. 3 is a perspective view showing a cutting die 20 of the cutting device for manufacturing a semiconductor device. The cutting die 20 has a lower die base 21 and an upper die base 22. Pillars 23 are provided on the upper surfaces of the four corners of the lower mold base 21,
Fitting portions 24 slidably fitted to the columns 23 are fixed to the lower surfaces of the four corners of the upper mold base 22.

An attachment portion 25 is provided at the center of the upper surface of the lower mold base 21, and a die (not shown) is attached. A mounting portion 26 is provided at the center of the lower surface of the upper die base 22, and a punch (not shown) is mounted. At the center of the upper surface of the upper mold base 22, a lifting ram 2 is provided.
The lower end of 7 is fixed.

A feed plate 30 for guiding the lead frame 1 is horizontally arranged between the lower mold base 21 and the upper mold base 22. The lead frame 1 is placed on the feed plate 30 and is intermittently transferred by a feed mechanism (not shown). Transport is
For example, from right to left. Therefore, the lowering of the lifting ram 27 causes cutting by the die and the punch.

The lead frame 1 is a strip body in which a plurality of unit lead frame patterns are arranged in series, and guide holes 35a to 35e each having a circular or elliptical shape or an elongated hole or the like used at the time of transfer or positioning are formed on both sides thereof. Are provided (see FIG. 10).

The unit lead frame pattern portion is shown in FIG.
As shown in 0, the frame body 36 is formed, and the sealing body 6 is formed in the center. A plurality of leads 7 extend in parallel from both sides of the sealing body 6. The tips of the leads 7 are connected to the frame 36, respectively. Further, dam bars 2 are provided on both sides of the sealing body 6 along the sealing body 6. The dam bar 2 connects adjacent leads 7. The outermost dam bar 2 connects the lead 7 and the frame body 36.
Further, from both ends (upper and lower ends in FIG. 10) of the sealing body 6,
Two tab suspension leads 37 are projected from each. The tab suspension lead 37 is connected to the frame body 36.

Although not shown, a tab is located at the center of the sealing body 6, and a semiconductor chip is fixed on the tab. Both ends of the tab are supported by two tab suspension leads 37, respectively. The electrodes of the semiconductor chip and the inner end portions of the leads 7 are electrically connected by a conductive wire. The sealing body 6 seals the tab, the semiconductor chip, the wire, and the inner end portion of the lead.

The sealing is performed by transfer molding. Therefore, by this transfer molding, a cured portion made of an insulating resin is formed at each position of the lead frame. That is, the gate hardening portion 38 is formed on one end side of the sealing body 6, and the flow cavity hardening portion 39 is formed on the opposite side.
The gate curing portion 38 is formed of an insulating resin cured in the gate portion of the transfer mold, and the flow cavity curing portion 39 is formed of an insulating resin cured in the flow cavity portion of the transfer mold. In addition, in FIG.
A portion colored in a light black between the outer periphery of and the dam bar 2 is a resin burr (resin burr) 11.

The cutting die 20 includes a lead frame 1
A plurality of dies and punches are incorporated along the transfer direction of. For example, in the first embodiment, three punched portions are provided. That is, as shown in FIG. 4 and FIG. 5, the punching portion is a flow cavity / gate punching portion 40, a resin dam bar punching portion 41, and an air vent punching portion 42 from left to right.

In the flow cavity / gate punching section 40, the gate hardening section 38 and the flow cavity hardening section 39 are cut and removed, and in the resin dam bar punching section 41, the dam bar 2 and the resin burr (resin burr) 11 are cut and removed, and the air vent punching section. At 42, the air vent cured portion is cut and removed.

As shown in FIGS. 5 and 4, a die, a punch and the like are incorporated in the mounting portions 25 and 26.
Here, the resin dam bar punching section 41 will be described with reference to FIGS. 4 to 9.

In the resin dam bar punching section 41, the die 3
As a punch 4, a dam bar punching punch 4b is provided as a punch 4. FIG. 7 is a perspective view showing the dam bar punching portion 3b (die 3) and the dam bar punching punch 4b (punch 4) on one side of the resin dam bar punching portion 41 and the lead frame 1. In FIG. 7, the lead frame 1 is schematically shown.

Further, as shown in FIG. 6, a sealing body 6 is received between the pair of dam bar punched portions 3b, and a receiver for maintaining the distance between the pair of dam bar punched portions 3b at a predetermined size. 3f is provided. In the figure, 46 and 47 are stays for size adjustment, 48 and 49 are passage holes 48 through which cut dam bars and resin burrs fall.
49.

In cutting the dam bar 2, as shown in FIG. 3, the dam ram 2 is cut and removed together with the resin burr (resin burr) 11 by lowering the elevating ram 27 and shearing between the punch 4 and the die 3. Will be done.

At this time, as shown in FIG. 2, since the receiving blade 5 of the die 3 which supports the lead 7 portion between the dam bar 2 and the sealing body 6 supports only the lead 7 portion, the side surface of the lead 7 is supported. The resin burrs (resin burrs) 11 adhered to the above will be cut off except for the portion continuous with the sealing body 6. That is, as shown in FIG. 1, the resin burr (resin burr) 11 separated from the tip of the receiving blade 5 remains in a continuous manner with the sealing body 6, and the residual resin burr 12 is the remaining resin burr 12.
On the extension side of the tip (closer to the sealing body) separated from the above, the residual resin burr 12 may remain at the root of the lead 7 from the sealing body 6, but the residual resin burr 12 is close to the sealing body 6 and Since the force of integration with 6 is large, peeling (cracks) at the interface between the residual resin burr 12 and the lead 7 is less likely to occur, and is less likely to fall off during subsequent transportation or the like.

In other words, at the tip of the punch 4 near the sealing body 6, the resin burr 11 is hit by the punch 4 and falls off. At this time, the resin burr 1 at the tip of the punch 4
1 also peels from the side surface of the lead 7 and falls off, but punch 4
The resin burr 11 removed from the tip of is connected to the sealing body 6,
Since it is integrated with the sealing body 6, it remains after the sealing body 6. Since the residual resin burr 12 shown in FIG. 1 is continuous with the sealing body 6 in the entire longitudinal direction, the residual resin burr 12 is hard to drop off.

In the manufacture of a semiconductor device, after fixing a semiconductor chip to a predetermined portion of the lead frame 1, the electrode of the semiconductor chip and the tip of the lead 7 are connected by a conductive wire, and then the semiconductor chip is transferred by transfer molding. , The wires and the inner end portions of the leads are covered with the sealing body 6 made of resin, and the flow cavity portion and the like are also covered to form the flow sealing portion and the like.

After that, for example, using the semiconductor device manufacturing cutting apparatus according to the first embodiment, the resin dam bar is punched,
Air vent punching is performed, and thereafter, lead cutting, lead molding, and lead size determination cutting are performed using a processing device (not shown) to manufacture a semiconductor device 50 in which the lead 7 is a gull wing type as shown in FIG.

The semiconductor device manufacturing technique according to the first embodiment has the following effects. (1) In the cutting die 20 for cutting the dam bar 2, the side edge of the die portion supporting the lead portion between the dam bar 2 and the sealing body 6 is located inside the side edge of the lead 7. It is structured. Therefore, when the resin burrs 11 such as between the leads are struck and cut by the punch 4, the resin burrs 11 adhered to the side surfaces of the leads 7 are not supported by the die part, and therefore peel off at the interface with the side surfaces of the leads. become. As a result, it is possible to prevent the residual resin burr 12 from adhering to the leads 7 that easily fall off.

(2) Since the residual resin burr 12 can be prevented from falling off by the above (1), the resin block due to the resin burr does not adhere to the lead frame (lead) or the package, and the lead frame is clamped by a cutting die or the like. However, it is possible to prevent the occurrence of package cracks, semiconductor chip cracks, and the like, because the resin lumps are not included and clamped, and it is possible to manufacture semiconductor devices of excellent quality with high yield.

(3) Since the residual resin burr 12 can be prevented from falling off by the above (1), the resin block due to the resin burr does not adhere to the lead portion of the lead frame, and the surface of the lead is struck when the mold is clamped. There are marks,
It will not bend or bend.

(4) According to the above (1), the residual resin burr 12 can be prevented from falling off, so that the resin block due to the resin burr does not adhere to the transfer rail in the mold or the transfer rail of the apparatus, which is caused by the resin block. Poor conveyance, damage to the mold and damage to the lead frame (semiconductor device) are less likely to occur, and productivity and yield can be improved.
It is possible to reduce the manufacturing cost of the semiconductor device.

(Embodiment 2) FIG. 12 is a schematic plan view showing a correlation between a punch and a die for cutting a dam bar in a semiconductor device manufacturing method according to another embodiment (Embodiment 2) of the present invention. In the second embodiment, a die portion (receiving blade 5) that supports the lead 7 between the dam bar 2 and the sealing body 6.
Since the side edge of the punch 4 is located inside the side edge of the lead 7, the width of the punch 4 for cutting the dam bar 2 is partially widened between the dam bar 2 and the sealing body 6.

In the second embodiment, the dam bar 2 and the sealing body 6 are used.
The widths b and c of the punch portion located between the
The dam bar 2 and the resin burr 11 are cut and removed by partially widening the punch width a of the portion to be cut.
As a result, the resin burrs are more reliably separated from the leads 7, and the residual resin burrs 12 that easily fall off are less likely to occur.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say. In the above-described embodiment, the manufacturing technique of the SOP type semiconductor device is applied. However, the manufacturing technique of the QFP (Quad Flatpack Package) type semiconductor device in which a plurality of leads are respectively projected from the four sides of the rectangular sealing body is applied. Can be applied in the same manner and has the same effect.

In this case, it is necessary to similarly cut the dam bar between the tab suspension lead supporting the tab and the adjacent lead by punching. In this case as well, the lead which is the tab suspension lead between the dam bar and the sealing body. The side edge of the die portion that supports the inner side of the lead is located inside the side edge of the lead so that the resin burr is reliably separated from the side surface of the lead (tab suspension lead).

[0042]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows. (1) It is possible to provide a manufacturing technique of a semiconductor device in which the resin burr is less likely to fall off. (2) Since the adverse effect caused by the adhesion of the resin block can be prevented, the quality of the semiconductor device can be improved and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view showing a part of a lead frame in a state where a dam bar is cut in a method for manufacturing a semiconductor device according to an embodiment (Embodiment 1) of the present invention.

FIG. 2 is a schematic plan view showing a correlation between a punch and a die for cutting the dam bar.

FIG. 3 is a perspective view showing a part of a cutting device used in manufacturing the semiconductor device of the first embodiment.

FIG. 4 is a schematic plan view showing a lower mold of the cutting device.

FIG. 5 is a schematic sectional view showing a lower mold of the cutting device.

FIG. 6 is a schematic cross-sectional view showing a dam bar cutting portion in the cutting device.

FIG. 7 is a schematic exploded perspective view showing a punch, a die and the like for cutting the dam bar.

FIG. 8 is a perspective view of a die for cutting the dam bar.

FIG. 9 is a plan view of a part of the dam bar cutting die.

FIG. 10 is a plan view showing a part of the lead frame that has been molded in the manufacturing of the semiconductor device of the first embodiment.

FIG. 11 is a perspective view of a semiconductor device manufactured by the method of manufacturing a semiconductor device according to the first embodiment.

FIG. 12 is a schematic plan view showing the correlation between a punch and a die for cutting a dam bar in a method for manufacturing a semiconductor device according to another embodiment (second embodiment) of the present invention.

FIG. 13 is a schematic plan view showing the correlation between a punch and a die for dambar cutting in the manufacture of a semiconductor device prior to the present invention.

FIG. 14 is a perspective view showing a part of the lead frame cut by the dam bar.

[Explanation of symbols]

1 ... Lead frame, 2 ... Dam bar, 3 ... Die, 4 ... Punch, 5 ... Receiving blade, 6 ... Sealing body, 7 ... Lead, 10 ... Die block, 11 ... Resin burr (resin burr), 12 ... Residual resin burr, 20 ... Cutting mold, 21 ... Lower mold base,
22 ... Upper mold base, 23 ... Struts, 24 ... Fitting portion, 25
... Attachment part, 27 ... Lifting ram, 30 ... Feed plate, 35a to 35e ... Guide hole, 36 ... Frame body, 37 ... Tab suspension lead, 38 ... Gate hardening part, 39 ... Flow cavity hardening part, 40 ... Flow cavity -Gate punching portion, 41 ... Resin dam bar punching portion, 42 ... Air vent punching portion, 46, 47 ... Stays, 48, 49 ... Passage hole, 50 ... Semiconductor device.

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Claims (5)

[Claims] 1. A step of molding a part of a lead frame with an insulating resin to form a sealing body, and a dam bar for connecting a plurality of leads protruding from a side surface of the sealing body over a predetermined length. A method of manufacturing a semiconductor device, comprising the steps of cutting and removing with a punch and a die and also cutting and removing resin burrs between the leads by the punch, wherein a lead portion between the dam bar and the sealing body is supported. A method of manufacturing a semiconductor device, wherein the side edge of a die portion is located inside the side edge of the lead, and the dam bar is cut. 2. A punch portion located between the dam bar and the sealing body is partially wider than a punch width of a portion for cutting the dam bar to cut and remove the dam bar and the resin burr. The method for manufacturing a semiconductor device according to claim 1, further comprising: 3. A semiconductor in which a dam bar connecting a plurality of leads juxtaposed from a side surface of the encapsulation body of a lead frame partially having the encapsulation body is cut by a cutting die die and a punch cutting operation. A cutting device for manufacturing a device,
The cutting device having a structure in which a side edge of a die portion supporting a lead portion between the dam bar and the sealing body is located inside a side edge of the lead. 4. The die and punch are arranged at a plurality of positions along the transfer direction of the lead frame in the cutting die, and different lead frame parts are cut at the respective positions. The cutting device according to claim 3, wherein: 5. The punch portion located between the dam bar and the sealing body has a width that is partially wider than a punch width of a portion that cuts the dam bar. The cutting device described in 1.