TWI718421B - Method for producing lead frame and lead frame - Google Patents

Abstract

Provided is a method for producing a lead frame, by which a vertical gap generated between separate die pads can be reduced. The method for producing a lead frame 1 according to the present disclosure includes, in the sequence set forth, the steps of (A) processing a processing material 80 into a shape of a lead frame including a die pad portion, (B) depressing the processing material 80, and (C) dividing the die pad portion to form separate die pads 21, 22.

Description

Manufacturing method of lead frame and lead frame

The present invention relates to a manufacturing method of a lead frame and a lead frame.

Lead frames are used in semiconductor packages to connect semiconductor components and external wiring. A known lead frame includes a plurality of separate wafer holders formed by dividing a wafer holder supporting and fixing a semiconductor element (for example, refer to Japanese Patent Laid-Open No. 2000-22036).

In the manufacturing process of the lead frame, press processing may be performed. In this pressing process, the wafer holder is displaced downward by a predetermined height so that the semiconductor element mounted on the wafer holder and the top end of the inner lead are on the same plane. In this way, the lead frame including the separated wafer holders may be stepped between the separated wafer holders due to the pressing process.

Therefore, in the present invention, a method of manufacturing a lead frame and a lead frame capable of suppressing the step between the separated wafer holders will be described.

A method of manufacturing a lead frame according to an embodiment of the present invention sequentially includes: (A) a process of processing a processed body into the shape of a lead frame including a wafer seat; (B) a process of pressing down the processed body; and (C) A step of dividing the wafer seat portion to form a separated wafer seat.

The lead frame of an embodiment of the present invention includes: a first inner lead and a second inner lead; a first die holder connected to the first inner lead; a second die holder separated from the first die holder and connected to The second inner lead connection; a first protrusion that is arranged on the first wafer holder and protrudes in a direction opposite to the second wafer holder; and a second protrusion that is arranged on the second wafer Seat, and protrudes toward a direction opposite to the first wafer seat.

According to the manufacturing method of the lead frame and the lead frame of the present invention, it is possible to suppress the generation of steps between the separated wafer holders.

In the following detailed description, for illustrative purposes, many specific details are proposed in order to provide a thorough understanding of the disclosed embodiments. However, it is obvious that one or more implementation manners can be implemented without these specific details. In other cases, in order to simplify the drawing, well-known structures and devices are schematically shown.

The embodiments of the present invention described below are examples for explaining the present invention. The present invention should not be limited to the following content.

<Outline of Implementation Mode>

[1] A method of manufacturing a lead frame according to an embodiment of the present invention sequentially includes: (A) a process of processing a processed body into the shape of a lead frame including a wafer seat; (B) pressing down the processed body A process of processing; and (C) a process of dividing the wafer seat portion to form a separated wafer seat.

In the manufacturing method of the lead frame described above, the body to be processed is processed into the shape of the lead frame including the wafer seat portion. Next, the to-be-processed body is pressed down. After that, the wafer seat portion is divided to form a separated wafer seat. Here, the wafer seat portion includes at least a wafer seat and internal leads connected to the wafer seat. In addition, the connection part mentioned later is also included in this wafer seat part. In the case where the lead frame including the divided wafer holders is pressed down, there is a possibility that a step (positional shift) between the separated wafer holders may occur. In this regard, as in the present embodiment, in the case of the manufacturing method of dividing the wafer seat portion after the press-down processing is performed, when the press-down processing is performed, the wafer seat portion is not yet divided. Therefore, it is possible to suppress the step (positional shift) between the separated wafer holders caused by the pressing down process.

[2] In the manufacturing method of [1] described above, it is preferable that the step (A) includes forming a connecting portion configured to connect a plurality of predetermined separation regions corresponding to the separation wafer seat to each other. In this case, the step (C) includes cutting the connecting portion. In this way, by cutting the connecting portion formed separately from the planned separation area to divide the wafer seat portion, it is possible to reliably form the separated wafer seat in the desired area of the wafer seat.

[3] In the manufacturing method of [2] above, it is preferable that the step (A) includes forming a plurality of the connection portions separated from each other. When the connection part is cut, the part corresponding to the connection part (for example, continuous to the connection part) in the planned separation area is suppressed by a stripper or the like, and the connection part is punched out. Here, before cutting the connection portion, surface treatment such as plating treatment is performed on the planned separation area. Therefore, it is preferable that the part suppressed by the above-mentioned stripper etc. is as small as possible. Regarding this point, by arranging a plurality of connecting portions apart from each other, there are portions that do not correspond to the connecting portions in the plurality of planned separation regions. Therefore, for example, compared with a case where a unique connection portion is provided along the boundary between a plurality of predetermined separation regions, it is possible to reduce a portion suppressed by a stripper or the like when the connection portion is cut.

[4] In the manufacturing method of [2] or [3] above, it is preferable that the step (A) includes both ends of the planned separation region in a direction intersecting the direction in which the plurality of planned separation regions are opposed to each other. Form a connection. To the both ends of the planned separation region (the both ends in the direction intersecting the direction in which the planned separation region faces each other), inner leads and the like are connected. Therefore, when pressing down, it is easy to apply a rotational force that shifts the planned separation area from its original position to the both end portions. As a result, there is a possibility of deformation that separates the predetermined area. In this regard, by providing the connecting portions at both ends of the planned separation region, it is possible to suppress the deformation of the planned separation region due to the force applied to the both ends.

[5] In the manufacturing method of [1] above, it is preferable that the step (A) includes: forming a predetermined separation region in such a manner that a plurality of predetermined separation regions corresponding to the separation wafer seat are respectively connected to different internal leads; And a connecting portion is formed between the inner leads that are different from each other. Also in this case, the wafer seat portion is divided by cutting the connection portion in the step (C). By providing the connecting portion between the inner leads, when the connecting portion is cut, it is possible to reduce the portion of the planned separation area suppressed by the stripper.

[6] The lead frame of an embodiment of the present invention includes: a first inner lead and a second inner lead; a first die holder connected to the first inner lead; a second die holder separated from the first die holder and connected to the first die holder. Two internal lead connections; a first protrusion arranged on the first wafer seat and protruding in a direction opposite to the second wafer seat; and a second protrusion arranged on the second wafer seat and facing the first wafer seat The opposite direction is prominent. According to the above-mentioned manufacturing method, the lead frame can be obtained by dividing the wafer holder after the press-down process. The lead frame is between the separated wafer holders (the first wafer holder and the second wafer holder), and includes portions (first protrusions and second protrusions) protruding toward the opposite wafer holders, and the protruding portions are The remaining part of the cut connection. In such a lead frame, deformation of the wafer seat can be suppressed in the manufacturing process (specifically, during press processing). Therefore, it is possible to suppress the generation of steps between the separated wafer holders. In addition, by providing the first protrusion and the second protrusion, it is possible to increase the surface area of the side surface (the surface facing the other wafer holder) of the separated wafer holder. Therefore, the resin adhesion at the time of resin sealing in the sealing process after the process (C) can be improved.

<Illustration of Implementation Mode>

Hereinafter, an example of an embodiment of the present invention will be described in more detail with reference to the drawings. In the following description, the same reference numerals are used for the same elements or elements having the same functions. Repetitive description of these elements will be omitted.

[Lead Frame]

First, referring to FIG. 1, the structure of the lead frame 1 will be described. The lead frame 1 is a component included in an integrated circuit such as IC (Integrated Circuit) or LSI (Large-Scale Integrated circuit), or a component included in a semiconductor package that includes discrete semiconductors, photocouplers, or LEDs (Light Emitting Diode) and other semiconductor components. The lead frame 1 fixes semiconductor elements in these integrated circuits and semiconductor packages, and connects the semiconductor elements with external wiring. For example, the lead frame 1 is formed by punching (pressing) or etching a thin plate (worked body) of a metal raw material, such as a copper alloy-based raw material or an iron alloy raw material. In the following description, an example in which the lead frame 1 is formed by punching processing will be described.

As shown in FIG. 1, the lead frame 1 has a substantially rectangular shape in plan view. The lead frame 1 includes a die base 12, inner leads 13, outer leads 14, slits 15 and protrusions 16. In the following description, the short-side direction of the lead frame 1 in a plan view may be described as the X direction and the long-side direction may be described as the Y direction.

The wafer holder 12 arranged at the center of the lead frame 1 supports and fixes a semiconductor element (IC chip). The semiconductor element is supported and fixed on the wafer base 12 by supporting and fixing the semiconductor element on the bonding material (patch material) coated on the wafer base 12. As the patch material, for example, silver paste obtained by mixing silver powder with epoxy resin is used. The wafer holder 12 is divided into two parts at the center position in the X direction, and has separate wafer holders 21 and 22. That is, the separated wafer holders 21 and 22 are separated and formed adjacent to each other at predetermined intervals along the X direction. The separated wafer holder 21 (first wafer holder) is connected to inner leads 31 and 33 (first inner leads) described later at both ends in the Y direction. The separated wafer holder 22 (second wafer holder) is connected to inner leads 32 and 34 (second inner leads) described later at both ends in the Y direction.

The inner leads 13 arranged on the periphery of the wafer holder 12 connect the semiconductor elements on the wafer holder 12 with external wiring. The inner lead 13 includes: an inner lead 31 (first inner lead) opposed to one end side of the separated wafer holder 21 in the Y direction; an inner lead 32 (second inner lead) opposed to one end side of the separated wafer holder 22 ); the inner lead 33 (first inner lead) opposed to the other end side of the separated wafer holder 21; and the inner lead 34 (second inner lead) opposed to the other end side of the separated wafer holder 22.

The inner leads 31, 32, 33, and 34 each include three leads that are arranged side by side in the X direction and extend along the Y direction. Among the three side-by-side leads included in the inner lead 31, only the middle lead is connected to the split wafer holder 21 (specifically, the center portion in the X direction on the Y direction end side of the split wafer holder 21). Similarly, among the three leads included in the inner lead 32, only the middle lead is connected to the split wafer holder 22 (specifically, the center portion in the X direction on the Y direction end side of the split wafer holder 22). Among the three side-by-side leads included in the inner lead 33, only the outer lead is connected to the separated wafer holder 21 (specifically, the outer portion in the X direction on the other end side of the separated wafer holder 21 in the Y direction). Similarly, among the three leads included in the inner lead 34, only the outer lead is connected to the separated wafer holder 22 (specifically, the outer portion in the X direction on the other end side of the separated wafer holder 22 in the Y direction). In the lead frame 1, the inner leads 31, 32, 33, 34, which are connected to the die pad 12, are oriented in a direction crossing the X direction and the Y direction (height direction, more specifically Downward direction) bend. As a result, the wafer holder 12 is displaced downward by a predetermined height. By performing this pressing process, the semiconductor element mounted on the wafer holder 12 and the top end of the inner lead 13 can be arranged on the same plane. The tip of the inner lead 13 is connected to the semiconductor element by wire bonding using gold wire or the like.

The outer lead 14 arranged outside the inner lead 13 in the Y direction connects the inner lead 13 to the external wiring. The outer leads 14 include: outer leads 41, including leads connected to the leads of the inner leads 31; outer leads 42, including leads connected to the leads of the inner leads 32; and outer leads 43, including leads connected to the inner leads 33. And outer leads 44, including leads connected to each lead of the inner leads 34.

The slits 15 are arranged at both ends of the lead frame 1 in the Y direction. The slit 15 is a punched portion formed in substantially the entire area of the lead frame 1 in the X direction. The slits 15 are formed on the inner side in the X direction than the guide holes 17 formed at the four corners of the lead frame 1. The slit 15 is formed to absorb stress. When performing the punching process, the positioning pin is inserted into the guide hole 17. The lead frame 1 may be deformed due to stress generated from the die pad 12 and the inner leads 13 toward both end sides in the Y direction. In this case, there is a case where the position of the guide hole 17 with respect to the wafer holder 12 and the like is shifted. In this case, it may affect the punching process. In this regard, by forming the slit 15, it is possible to release the stress generated from the wafer holder 12, the inner leads 13, and the like toward both end sides in the Y direction from the slit 15. Therefore, it is possible to suppress the deformation of the lead frame 1 due to the aforementioned stress, that is, it is possible to suppress the positional deviation of the guide hole 17 with respect to the wafer holder 12 and the like.

The protruding part 16 is arranged on the separated wafer holders 21 and 22. The protruding portion 16 protrudes in the direction of the opposing separation wafer holders 22 and 21. The protrusion 16 includes a protrusion 61 and a protrusion 62. The protruding portions 61 are arranged at both ends in the Y direction of the part facing the separated wafer holder 22 in the separated wafer holder 21. The protruding portions 62 are arranged at both ends in the Y direction of the portion of the separated wafer holder 22 that is opposed to the separated wafer holder 21. That is, the protrusion 61 (first protrusion) is arranged on the separated wafer holder 21 and protrudes in a direction facing the separated wafer holder 22. In addition, the protruding portion 62 (second protruding portion) is arranged on the separated wafer holder 22 and protrudes in a direction facing the separated wafer holder 21. In the manufacturing process of the lead frame 1, the part of the connection part 90 remaining after a part of the connection part 90 (refer FIG. 2 (a). Specifically mentioned later) is cut off is formed as the protrusion part 61, 62. The protrusion lengths of the protrusions 61 and 62 are extremely short compared to either the length of the lead frame 1 in the X direction and the length of the separated wafer holder 21 (or the separated wafer holder 22) in the X direction. For example, the protrusion length of the protrusions 61 and 62 is set to 50 μm to 100 μm. However, the protruding length of the protruding parts 61 and 62 is an example. The protruding length is not limited to this example.

[Manufacturing method of lead frame]

Next, a method of manufacturing the lead frame 1 having the wafer holder 12 (separated wafer holders 21, 22) divided into a plurality of parts will be described with reference to FIGS. 2 to 8. The lead frame 1 goes through the lead frame shape forming process (refer to the following (A) process, Fig. 2 (a)), the pressing process (refer to the following (B) process, Fig. 2 (b)), and connection Partial cutting process (refer to the following (C) process, Fig. 2 (c)) to manufacture. More specifically, the manufacturing method of the lead frame 1 shown in FIG. 2 includes the following steps in order. (A) A process of processing a thin plate of a metal material, that is, a strip-shaped processed body 80 into the shape of a lead frame (B) A process of pressing down the processed body 80 (C) By cutting the processed body 80 Process of processing the connecting portion 90 of the body 80 to divide the wafer holder into separate wafer holders 21 and 22

In addition, in FIGS. 2( a) to 2 (c) showing the manufacturing process of the lead frame 1, for convenience of description, only the shape of one lead frame 1 is shown. However, actually, in the step (A) described above, the strip-shaped workpiece 80 is processed into the shape of a plurality of lead frames 1. Then, the process (B) and the process (C) described above are performed on the to-be-processed body 80 having the shape of the plurality of lead frames 1. After that, the packaging process is carried out. After that, the plurality of lead frames 1 are divided into each other. In the packaging process, first, semiconductor elements are bonded to the separated wafer holders 21 and 22 of the lead frame 1. Next, the semiconductor element is connected to the tips of the inner leads 31, 32, 33, and 34 by wire bonding. Finally, for example, using a thermosetting resin, the separated wafer holders 21, 22 and the inner leads 31, 32, 33, 34 are molded together with semiconductor elements.

Initially, the step (A) described above is carried out. In the step (A), the workpiece 80 is punched with a punch of a die (punching device), thereby forming a lead frame shape. For example, the mold sequentially punches out a belt-shaped object 80 intermittently fed in one direction by a pair of rollers (see FIG. 3 ). (A) The process includes the following processes in order. (A-0) Step of forming guide holes 17 in the belt-shaped object 80 (a-1) Step of forming slits 15 in the object 80 (a-2) Forming the outside on the object 80 Step of lead 14 (a-3) Step of forming inner lead 13 on to-be-processed body 80 (a-4) Step of forming planned separation regions 210 and 220 and connecting portion 90

The step (A) will be described with reference to FIGS. 3 to 8. The step (a-0) is a step of forming guide holes 17 at both ends in the width direction (Y direction) of the belt-shaped workpiece 80 (see FIG. 3(a) and FIG. 4(a)). The guide hole 17 is a hole into which a positioning pin for positioning the workpiece 80 during punching processing is inserted. In the step (a-0), the punch of the die punches both ends of the Y-direction of the workpiece 80 at the same time, thereby simultaneously forming the two guide holes 17. Guide holes 17 are formed at both ends in the Y direction of the belt-shaped workpiece 80 intermittently fed out by the rollers. As a result, guide holes 17 are formed around (four corners) of the shape of one lead frame.

The step (a-1) is a step of forming slits 15 extending in the X direction at both ends in the Y direction of the workpiece 80 (see FIG. 3(b) and FIG. 4(b)). In more detail, the slits 15 are formed on the inner side along the X direction than the guide holes 17 formed at the four corners of the lead frame 1. In the step (a-1), the punch of the die simultaneously punches both ends of the workpiece 80 in the Y direction along the X direction. Thus, two slits 15 extending in the X direction are formed at the same time.

In the step (a-2), the outer lead 14 is formed on the inner side of the slit 15 along the Y direction (see Fig. 3(c), (d) and Fig. 5(a), (b)) . In the step (a-2), first, the punch of the die is along the Y direction, and punching regions 45 are formed at four positions on the inner side of the slits 15 formed at both ends in the Y direction. The four punching regions 45 extend the same length along the Y direction, and are arranged at equal intervals along the X direction (see FIG. 5(a)). Next, the punches of the die respectively form a punching area 46 between the punching areas 45 adjacent to each other. The punched area 46 extends along the Y direction by the same length as the punched area 45 (see FIG. 5(b)). That is, the punches of the die form the punching areas 46 at three locations on both end sides in the Y direction.

Thereby, as shown in FIG. 5( b ), the outer lead 14 extending in the Y direction is formed between the punched regions 45 and 46 adjacent to each other. In more detail, on one end side in the Y direction, an outer lead 41 including three leads connected to the inner lead 31 (refer to FIG. 6(b)), and an outer lead 41 including three leads connected to the inner lead 32 (refer to FIG. 6(b)) are formed. )) The external lead 42 of the 3 leads connected. Furthermore, on the other end side in the Y direction, an outer lead 43 including three leads connected to the inner lead 33 (see FIG. 6(b)) and an inner lead 34 (see FIG. 6(b)) are formed. Connect the external leads 44 of the 3 leads.

In the step (a-3), the inner lead 13 is formed on the inner side of the outer lead 14 along the Y direction (see Fig. 3(e), (f) and Fig. 6(a), (b)) . In the step (a-3), first, the punch of the die forms punching regions 35 extending in the Y direction at both ends in the X direction. At the same time, the punch of the die forms a punched area 36 extending in the Y direction in the center portion of the X direction (see FIG. 6(a)). The punched area 35 is formed by punching out substantially the entire area between the punching areas 45 at both ends in the Y direction. The punching regions 36 are formed along the Y direction at four positions on the inner side of the punching regions 45 respectively formed at both ends in the Y direction. The four blanking areas 36 extend the same length (shorter length than the blanking area 35) along the Y direction. Two of the four punching regions 36 are formed on one end side in the Y direction. The remaining two punching regions 36 are formed on the other end side in the Y direction. In addition, the two punching regions 36 on the one end side in the Y direction are the same as the two punching regions 36 on the other end side in the Y direction, and are arranged to face each other along the X direction. And, on both ends in the Y direction, the punching area 35 on the one end side in the X direction, the punching area 36 near the punching area 35 on the one end side in the X direction, and the punching area 35 near the other end side in the X direction The punching area 36 and the punching area 35 on the other end side in the X direction are arranged at equal intervals along the X direction. Next, the punch of the die forms a punching area 37 between the punching areas 35 and 36 adjacent to each other, between the punching areas 36 and 36 and between the punching areas 36 and 35 respectively. Here, the punched area 37 extends along the Y direction with the same length as the punched area 36. At the same time, the die punch forms a punched area 95 extending in the Y direction in the center portion of the lead frame 1 (refer to FIG. 6( b )).

Thus, as shown in FIG. 6(b), between the adjacent punching areas 35 and 37, between the punching areas 37 and 36, between the punching areas 36 and 37, the punching areas 37, Between 36, between the punching areas 36 and 37, and between the punching areas 37 and 35, inner leads 13 extending along the Y direction are formed. In more detail, on one end side in the Y direction, an inner lead 31 including three leads connected to the outer lead 41 and an inner lead 32 including three leads connected to the outer lead 42 are formed. Furthermore, on the other end side in the Y direction, an inner lead 33 including three leads connected to the outer lead 43 and an inner lead 34 including three leads connected to the outer lead 44 are formed.

In the step (a-4), the top end of the inner lead 13 (the side opposite to the side to which the outer lead 14 is connected) is further punched out to define the area for separating the planned areas 210, 220 and the connecting portion 90 . That is, in this step, the planned separation regions 210 and 220 and the connecting portion 90 are formed (see (g) to (i) of FIG. 3, (a), (b) of FIG. 7 and FIG. 8). By cutting the connecting portion 90 in the step (C) described later, the separation wafer holders 21 and 22 are formed from the planned separation regions 210 and 220, respectively. The connecting portion 90 is configured to connect a plurality of planned separation regions 210 and 220 to each other.

In the step (a-4), first, the punch of the die forms a punching area 51 on the tips of the inner leads 31 and 32. At the same time, the punch of the die forms a punching area 52 on the tips of the inner leads 33 and 34 (see FIG. 7(a)). The punched area 51 is punched out into a quadrangular shape, for example. The punching area 51 extends in the X direction between the two punching areas 36. Furthermore, the punching area 51 extends in the Y direction from the substantially central portion of the punching area 36 to the front of the tip of the punching area 36. The punched area 52 is punched out into a quadrangular shape, for example. The punching area 52 extends in the X direction between the punching areas 37 on both end sides in the X direction. Furthermore, the punched area 52 extends in the Y direction from the substantially central portion of the punched area 37 to the front of the tip of the punched area 37. Next, the punch of the die forms a punched area 53 at the tip of each of the inner leads 31 and 32 located on the outermost side in the X direction (see FIG. 7(b)). The punched area 53 is, for example, an area punched out into a quadrangular shape. The punching area 53 extends in the X direction from the punching area 35 between adjacent punching areas 37. Furthermore, the punched area 53 extends in the Y direction from the substantially central portion of the punched area 37 to the front of the tip of the punched area 37.

In this way, blanking areas 51, 52, and 53 are formed. As a result, as shown in FIG. 8, a region where the planned separation regions 210 and 220 and the connection portion 90 are separated is defined. The planned separation area 210 is connected only to the lead in the center of the inner lead 31 in the X direction and the lead of the inner lead 33 located at the outermost side in the X direction. The predetermined separation region 220 is connected only to the lead in the middle of the inner lead 32 in the X direction and the lead of the inner lead 34 located on the outermost side in the X direction.

In addition, as shown in FIG. 8, a connecting portion 90 is formed as a portion connecting the planned separation regions 210 and 220 to each other. The connecting portion 90 includes a plurality of connecting portions 91 and 92 separated from each other. The connecting portions 91 and 92 are configured to connect both ends of the planned separation regions 210 and 220 in the Y direction. That is, the connecting portion 91 connects the Y-direction end portions of the planned separation regions 210 and 220. The connecting portion 92 connects the other ends of the planned separation regions 210 and 220 in the Y direction. In this way, in the step (a-4), a plurality of connection portions 91 and 92 separated from each other are formed. At this time, the connecting portions 91 and 92 are arranged at both ends of the planned separation regions 210 and 220 in the Y direction.

The above-mentioned (a-0) to (a-4) steps are performed to complete the (A) step, thereby processing the strip-shaped workpiece 80 into the shape of the lead frame including the wafer seat. After the step (A) and before the pressing down in the step (B), the surfaces of the planned separation regions 210 and 220 may be plated. For example, a plating solution containing a precious metal such as silver, nickel, or palladium is sprayed from a plating nozzle of a conventional plating apparatus toward the surface of the planned separation regions 210 and 220 to perform a plating process.

Next, the step (B) described above is carried out (refer to (b) of FIG. 2 ). In the step (B), the processed body 80 (the processed body 80 processed into the shape of a lead frame) that has been plated after the (A) step is intermittently fed out in one direction by a roller while using a mold Perform press processing. For example, the press processing is performed using a die equipped with an upper die and a lower die, the upper die is equipped with a punch for bending, and the lower die has an opening corresponding to the amount of bending. That is, in the step (B), the upper mold equipped with the bending punch is lowered, and the separation planned regions 210 and 220 included in the wafer holder are pressed downward. As a result, the semiconductor elements arranged on the separate wafer holders 21 and 22 and the tips of the inner leads 13 can be arranged on the same plane.

Next, the step (C) described above is implemented (see (c) of FIG. 2 ). In the (C) step, the connection portion 90 of the to-be-processed body 80 after the (B) step is cut. Thus, the wafer holder is divided into separate wafer holders 21 and 22. Specifically, the connection parts 91 and 92 (refer to FIG. 2(b)) that connect both ends in the Y direction of the planned separation regions 210 and 220 are simultaneously punched out by the punch of the die to cut the connection parts 91 and 92. In this way, the separated wafer holders 21 and 22 shown in FIG. 2(c) are formed. After the step (C), a part of the cut connecting portions 91 and 92 remains in the separated wafer holders 21 and 22 as the protruding portion 16 (refer to FIG. 1 ). The protrusion 16 includes a protrusion 61 and a protrusion 62. The protruding portions 61 are arranged at both ends in the Y direction in the portion of the separated wafer holder 21 that faces the separated wafer holder 22. The protruding portions 62 are arranged at both ends in the Y direction in the portion of the separated wafer holder 22 that faces the separated wafer holder 21. Using the above steps, the manufactured lead frame 1 includes the wafer holder 12 divided into a plurality of separate wafer holders 21 and 22.

Next, the manufacturing method of the above-mentioned lead frame 1 and the effects of the lead frame 1 will be described.

For example, in the manufacturing method of the lead frame 600 of the comparative example shown in FIG. 9, as shown in (a) of FIG. The wafer holders 521 and 522 of the wafer holders 512. After that, as shown in FIG. 9( b ), the separated wafer holders 521 and 522 are displaced downward by a predetermined height by pressing down. In this way, the processed body is processed into the shape of the lead frame including the divided wafer holders. In the press processing of the processed body, there is a possibility that steps are generated between the separated wafer holders 521 and 522 due to the press processing. Happening. For example, when both ends of the separated wafer holders 521, 522 are connected to inner leads (suspension leads), it is easy to act on the separated wafer holders 521, 522 in the state suspended by the inner leads, which may be caused by pressing down. The resulting rotational force. For example, when the thicknesses of the inner leads connected to both ends are different from each other, or when the positions (hanging positions) of the inner leads connected to both ends in the X direction are different from each other, such rotational force will change significantly. Big. In addition, for example, since the rotational force is different between the separated wafer holders 521 and 522, there is a possibility that a step (positional shift) between the separated wafer holders 521 and 522 may occur.

In order to solve such a problem, the manufacturing method of the lead frame 1 including the wafer holder 12 divided into a plurality of separate wafer holders 21 and 22 of the present embodiment sequentially includes: (A) processing the processed body 80 to include the wafer holder portion The process of forming the shape of the lead frame; (B) the process of pressing down the processed body 80 processed into the shape of the lead frame; and (C) dividing the wafer seat portion of the processed body 80 to form the separated wafer seat 21 , 22 process.

In the manufacturing method of the lead frame 1 of this embodiment, the to-be-processed body 80 processed into the shape of a lead frame is press-processed. After that, the wafer seat portion including the wafer seat 12 is divided. In this way, since the wafer seat portion is divided after the pressing down process, when the pressing down process is performed, the force generated by the pressing down process (for example, the above-mentioned rotational force) is applied to the undivided wafer seat part. In such a manufacturing method, it is possible to suppress the problem that occurs in the manufacturing method of the lead frame 600 of the comparative example described above, that is, the generation of a step (position shift) between the separated wafer holders. From the foregoing, it is understood that according to the manufacturing method of the lead frame 1 of the present embodiment, it is possible to suppress the generation of steps between the separated wafer holders 521 and 522.

In the process of processing the body 80 to be processed into the shape of the lead frame, a connecting portion 90 is formed, and the connecting portion 90 is configured to connect a plurality of planned separation regions 210 and 220 corresponding to the separation wafer holders 21 and 22 to each other. Then, in a subsequent step, the wafer seat portion including the wafer seat 12 is divided by cutting the connecting portion 90. In this way, the connecting portion 90 formed separately from the planned regions 210 and 220 is cut and separated, thereby dividing the wafer seat portion. Thereby, it is possible to reliably form the separated wafer holders 21 and 22 from a desired area of the wafer holder 12.

In the process of processing the workpiece 80 into the shape of the lead frame, a plurality of connection portions 91 and 92 separated from each other are formed. When the connecting portions 91, 92 are cut, the portions corresponding to the connecting portions 91, 92 (for example, continuous with the connecting portions 91, 92) in the planned separation regions 210, 220 are suppressed by the stripper etc., and the connecting portions 91, 92 are performed. The blanking and so on. Here, before cutting the connection portions 91 and 92, the separation planned regions 210 and 220 are subjected to surface treatment such as plating treatment. Therefore, it is preferable that the part suppressed by the above-mentioned stripper etc. is as small as possible. In this regard, by separating the plurality of connection portions 91 and 92 from each other, there are portions that do not correspond to the connection portions 91 and 92 in the plurality of planned separation regions 210 and 220. Therefore, for example, compared with a case where a unique connection portion is provided along the boundary between the plurality of planned separation regions 210 and 220, it is possible to reduce the portion suppressed by the stripper when the connection portions 91 and 92 are cut.

In the process of processing the body 80 to be processed into the shape of the lead frame, both ends of the planned separation regions 210 and 220 along the direction (Y direction) intersecting the directions in which the plurality of planned separation regions 210 and 220 are opposed to each other Section, connecting sections 91 and 92 are arranged. Since the inner leads 31, 32, 33, and 34 are connected to both ends of the planned separation areas 210, 220 in the Y direction, when the pressing process is performed, a rotational force is easily applied to the both ends, which may cause Separate the deformation of the predetermined area. In this regard, by providing the connecting portions 91 and 92 at both ends of the planned separation regions 210 and 220, it is possible to suppress the deformation of the planned separation regions 210 and 220 due to the force applied to the both ends.

As shown in FIG. 1, the lead frame 1 of the present embodiment includes: inner leads 31, 32, 33, 34; a separate wafer holder 21 connected to the inner leads 31, 33; separated from the separated wafer holder 21 and connected to the inner leads 32 and 34 are connected to the separated wafer holder 22; the protrusion 61 arranged on the separated wafer holder 21 and protruding to face the separated wafer holder 22; and the protrusion 61 arranged on the separated wafer holder 22 and opposed to the separated wafer holder 21 The protruding portion 62 is placed in the manner of placement. The protruding portion 61 and the protruding portion 62 can increase the surface area of the side surfaces (surfaces facing each other) separating the wafer holders 21 and 22. Therefore, it is possible to improve the adhesiveness of the resin when the resin sealing is performed in the sealing step.

The embodiments of the present invention have been described above, but the embodiments of the present invention are not limited to the above-mentioned embodiments. For example, the present embodiment is not limited to the above-mentioned embodiment in which the connection portions 91 and 92 directly connect the separation planned regions 210 and 220 included in the wafer seat portion to each other. For example, the connecting portion may be arranged between the inner leads included in the wafer seat portion. In this case, as shown in FIG. 10(a), in the process of processing the processed body 80 into the shape of the lead frame, it is also possible to connect the inner leads 31 and 32 with a plurality of predetermined separation regions, respectively, and Punching is performed so that the connecting portion 190 is formed between the inner leads 31 and 32. In this state, as shown in FIG. 10(b), the predetermined region is depressed downward by pressing down. Finally, as shown in (c) of FIG. 10, the connecting portion 190 is cut to form the separated wafer holders 121 and 122. Thus, the lead frame 100 is manufactured. In the lead frame 100, similarly to the lead frame 1, the protrusion 116 is generated by cutting the connecting portion. That is, as shown in FIG. 10( c ), in the inner lead 31 connected to the separate wafer holder 121, a protrusion 161 that protrudes so as to face the inner lead 32 is formed. Similarly, in the inner lead 32 connected to the separate wafer holder 122, a protrusion 162 that protrudes so as to face the inner lead 31 is formed.

In addition, in the above-described embodiment, the protruding portions 61 and 62 are formed in the separated wafer holders 21 and 22, and the protruding portions 61 and 62 are the remaining parts of the connecting portion 90 cut in the manufacturing process of the lead frame 1. However, for example, in the manufacturing process of the lead frame, when the connecting portion 365 (hatched portion in FIG. 11) is cut, as shown in FIG. 11, the recesses 361 and 362 may be formed in the separate wafer holders 321 and 322, respectively. That is, the shape produced by cutting the connecting portion may be the convex shape shown in FIG. 1. Alternatively, the shape may be a concave shape like the concave portions 361 and 362 in FIG. 11. In addition, as shown in FIG. 11, the punch 369 forming the recesses 361 and 362 punches out the area including the periphery of the connecting portion 365. The depth of the recesses 361 and 362 is not particularly limited. The preferred depth is 50 μm to 100 μm. In this case, by increasing the surface area of the side surfaces (surfaces facing each other) separating the wafer holders 321 and 322, the resin adhesion at the time of resin sealing in the sealing process can also be improved.

The detailed description has been given for the purpose of example and description. Based on the above teachings, many modifications and changes are possible. The detailed description is not without omission or intended to limit the subject matter described here. Although the subject has been described with specific structural features and/or method processes through text, it should be understood that the subject matter defined in the scope of the patent application is not necessarily limited to the specific features or specific processes described. More precisely, the specific features and specific processes described are described as examples of implementing the scope of the patent application.

1,600‧‧‧Lead frame 12,512‧‧‧Chip base 13,31,32,33,34‧‧‧Internal lead 14,41,42,43,44‧‧‧External lead 15‧‧‧Slit 16, 61, 62, 116, 161, 162‧‧‧Protrusion 17‧‧‧Guide hole 21,22,121,122,321,322,521,522‧‧Separate wafer holder 35,36,37,45 , 46, 51, 52, 95‧‧‧Blanking area 80, 180, 580‧‧‧Working body 90, 91, 92, 190, 365‧‧‧Connecting part 210, 220‧‧‧Separation planned area 361, 362‧‧‧Concave 369‧‧‧Punch

Fig. 1 is a plan view showing an example of a lead frame. FIG. 2 is a plan view explaining the manufacturing process of the lead frame. FIG. 2(a) is a plan view explaining the lead frame shape forming step. Fig. 2(b) is a plan view explaining the press working step. FIG.2(c) is a top view explaining the connection part cutting process. 3 is a plan view showing the overall layout of the punching process in the lead frame shape forming step. (A) and (b) of FIG. 4 are enlarged plan views showing (a) and (b) of FIG. 3 in the layout shown in FIG. 3. (A) and (b) of FIG. 5 are enlarged plan views showing (c) and (d) of FIG. 3 in the layout shown in FIG. 3. (A) and (b) of FIG. 6 are enlarged plan views showing (e) and (f) of FIG. 3 in the layout shown in FIG. 3. (A) and (b) of FIG. 7 are enlarged plan views showing (g) and (h) of FIG. 3 in the layout shown in FIG. 3. Fig. 8 is an enlarged plan view showing (i) of Fig. 3 in the layout shown in Fig. 3. Fig. 9 is a diagram illustrating a manufacturing process of a lead frame of a comparative example. (A) of FIG. 9 is a plan view explaining the lead frame shape forming step. Fig. 9(b) is a plan view showing a pressing process. Fig. 10 is a plan view showing an example of a lead frame of a modification. FIG. 11 is a plan view showing an example of a lead frame of a modification.

1‧‧‧Lead frame

12‧‧‧Chip Block

21、22‧‧‧Separation chip holder

80‧‧‧Processed body

90, 91, 92‧‧‧Connecting part

Claims (6)

A method of manufacturing a lead frame, characterized by sequentially including: (A) a process of processing a processed body into the shape of a lead frame including a wafer seat; (B) a process of pressing down the processed body And (C) after the wafer seat portion is divided to form a plurality of separated wafer seats, a semiconductor element is bonded to the separated wafer seats, and then the plurality of separated wafer seats are molded in a package. The method of manufacturing a lead frame according to claim 1, wherein the step (A) includes forming a connecting portion configured to connect a plurality of predetermined separation regions corresponding to the separation wafer holder to each other, ( C) The process includes cutting the connecting portion. The method of manufacturing a lead frame according to claim 2, wherein the step (A) includes forming a plurality of the connecting portions separated from each other. The method of manufacturing a lead frame according to claim 2 or 3, wherein the step (A) includes two portions of the predetermined separation region in a direction intersecting a direction in which the plurality of predetermined separation regions are opposed to each other. The end portion forms the connecting portion. The method of manufacturing a lead frame according to claim 1, characterized in that: (A) The process includes: forming the predetermined separation region in such a manner that a plurality of predetermined separation regions corresponding to the separation wafer holder are respectively connected to internal leads different from each other; and forming a connection between the internal leads different from each other Part, the step (C) includes cutting the connecting part. A lead frame is characterized by comprising: a first inner lead and a second inner lead; a first wafer holder connected to the first inner lead; a second wafer holder separated from the first wafer holder and connected to The second inner lead connection; a first protrusion that is arranged on the first wafer holder and protrudes in a direction opposite to the second wafer holder; and a second protrusion that is arranged on the second wafer Seat, and protrudes toward the direction opposite to the first wafer seat; wherein the edge of the first wafer seat opposite to the second wafer seat is opposite to the side of the first protrusion The side of the second wafer holder is stepped; the side of the second wafer holder opposite to the first wafer holder and the side of the second protruding portion opposite to the first wafer holder It is stepped.

Images