JPH09116068A - Manufacture of lead frame - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a lead frame which can correspond to further multi-terminal and high density of a semiconductor device. SOLUTION: For manufacturing a lead frame wherein at least an inner lead tip part is made thinner than a lead frame raw material and partial plating for wire bonding is applied to the thin part, at first, a tip of an inner lead part of a lead frame is connected by a connection part and at least an inner lead tip part is made thinner than a lead frame raw material and outline processing is performed for an outer lead part and others to a thickness of a lead frame raw material (a). Then, plating solution is sprayed to at least an inner lead tip part of the outline-processed lead frame by using a masking jig for applying plating (b). Thereafter, a tape for fixing an inner lead part is sticked and a connection part for connecting a tip of an inner lead part is cut and removed (d).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a lead frame capable of accommodating multiple terminals and miniaturization of a semiconductor device. In particular, at least the inner lead tips are made thinner than the lead frame material. The present invention relates to a method for manufacturing a lead frame in which the thin portion is partially plated for wire bonding.

[0002]

2. Description of the Related Art In recent years, with the trend toward higher performance of electronic devices and lighter, thinner and smaller electronic devices, LSIs, as typified by ASICs, have been increasingly integrated and functionalized. Multi-terminal ICs, especially ASICs represented by gate arrays and standard cells, microcomputers, DS
P (Digital Signal Processo)
As a package for providing a user with high cost performance such as r), a plastic QFP (Quad Flat Package) using a lead frame has become mainstream, and has now been put to practical use up to 300 pins or more.

The QFP uses the single-layer lead frame 1020 shown in FIG. 10 (b). As shown in FIG. 10 (a), the semiconductor element 1010 is mounted on the die pad 1021 and the surface of silver plating or the like is used. The processed tip of the inner lead 1022 and the terminal 1011 of the semiconductor element 1010
Are connected with a wire 1030 and sealed with a sealing resin 1040, and then the dam bar portion 1024 is cut,
The outer lead 1023 is formed into a gull wing shape. As described above, the QFP has outer leads 1 for electrically connecting to external circuits in four directions of the package.
The structure provided with 023 has been developed as one that can cope with the increase in the number of terminals. The single-layer lead frame 1020 used here is usually made of a metal material such as 42 alloy (42% nickel-iron alloy) or copper alloy having high electrical conductivity and high mechanical strength, and is formed by a photoetching method. Alternatively, the stamping method was used to form the shape as shown in FIG.

However, speeding up of signal processing of semiconductor devices,
Higher functionality has required more terminals. In the QFP, by narrowing the pitch of the inner leads and the pitch of the outer leads, the number of terminals has been increased without increasing the package size. The lead frame has been processed by the etching process shown in FIG. 9 using a photolithography technique for relatively high-definition ones, and the stamping method for the other ones. For further narrowing of the inner lead pitch,
A method has been adopted in which the lead frame material is made thin and etching is performed to achieve miniaturization.
Here, the etching processing method shown in FIG. 9 will be briefly described. First, both surfaces of a thin lead frame material 910 made of a copper alloy, 42 alloy (42% nickel-iron alloy), etc. were washed (FIG. 9 (a)), and water-soluble with potassium dichromate as a photosensitizer. A photoresist 920 such as casein resist is applied to the front and back surfaces of the lead frame material 910. (FIG. 9B) Next, after exposing the photoresist 920 with a high-pressure mercury lamp through the exposure mask substrate on which a pattern of a predetermined shape is formed, the photoresist is developed with a predetermined developing solution to obtain a predetermined lead frame. A resist pattern 930 having the same shape is formed. (FIG. 9 (c)) After that, resist hardening treatment, cleaning treatment, etc. are performed as necessary, and then an etching solution containing a ferric chloride aqueous solution as a main component is sprayed on both sides of the lead frame material 910. Then, the resist pattern 930 is etched to have a shape according to the resist pattern 930. (FIG. 9 (d)) The lead frame thus manufactured is
Silver plating is applied to a predetermined area, and after washing, drying, etc., the inner lead parts are taped with a polyimide tape with adhesive for fixing, or the tab suspension bar is bent by a predetermined amount if necessary. It was processed and the die pad part was down set. However, in the case of the above-mentioned etching method, the outer lead itself becomes thin, the width becomes narrow, and the strength is reduced due to the thinning of the plate thickness of the outer lead portion and the narrowing of the pitch. It is difficult to keep the skew and maintain coplanarity (flatness), and at the time of mounting, it is difficult to maintain the mounting accuracy of the package.

In order to deal with this, there has been proposed a method of forming only the inner lead portion to be thin by pressing, or a method of forming the tip of the inner lead to be thinner than the lead frame material by half-etching after outer shape processing of the lead frame. There is. The pressing method has problems in smoothness and dimensional accuracy of the tips of the inner leads, and the half etching method has a problem in that the plate making process is difficult and high accuracy cannot be obtained.

At the time of plating for wire-bonding the tip of the inner lead, a masking jig made of silicon rubber or the like is used to cover the non-plating area of the lead frame, and a predetermined amount of plating liquid is applied to the lead frame. Although a sparger type plating apparatus that sprays only on the area and performs plating is used, it has a problem of plating leakage to unnecessary portions. For example, FIG.
As shown in (a), since the tips of the inner lead portions are not fixed, the pressing member 1140 may push the plating, and the plating may adhere to the back surface of the lead frame 1110 that does not require plating. Further, as shown in FIG. 11B, when only the tips of the inner leads 1111 are formed to be thin, when a normal mask jig 1120 is used, the plating is attached to the unplated portion 1111A of the thin portion. Etc., there is a problem of plating leakage to the plating unnecessary part.

[0007]

Therefore, in a resin-sealed semiconductor device using a lead frame, there is a demand for a lead frame that can cope with the increase in the number of terminals of the semiconductor device without increasing the package size. That is, there is a demand for a lead frame that can secure the strength of the outer leads and can achieve a narrower pitch of the inner leads. The present invention is intended to provide a method for manufacturing a lead frame capable of accommodating more multi-terminals of semiconductor devices and high-density wiring. To provide a manufacturing method up to.

[0008]

According to the method of manufacturing a lead frame of the present invention, at least the inner lead tips are made thinner than the thickness of the lead frame material, and the thin portion is partially plated for wire bonding. A method of manufacturing a lead frame, which comprises sequentially connecting the tips of inner lead portions of a lead frame with a connecting portion and making at least the inner lead tips thinner than the thickness of the lead frame material, such as an outer lead portion. Etching process for external processing to the thickness of the lead frame material,
Partial plating process in which the plating solution is sprayed using a masking jig on at least the inner lead tip of the lead frame that has been externally processed in the etching process to perform plating, and tape for fixing the inner lead part is taped. The method is characterized by including a step and a step of cutting and removing a connecting portion that connects the tips of the inner lead portions. The plating masking jig described above is a mask that closely covers the non-plated portion according to the shape of the lead frame and serves as a mask. The plating area of the inner lead portion is an opening, and the opening is a plating solution. Is formed so as to be gradually narrowed toward the plating region side of the lead frame so that the lead region is easily applied to the plating region. Further, in the above etching process, a predetermined resist pattern is provided on both sides of the lead frame material, and etching is performed using this as an etching resistant mask. The first etching is performed from one side or both sides of the lead frame material, After etching a predetermined amount without penetrating the lead frame material, stop the etching, fill the hole on one side of the manufactured lead frame material with an etching resistant filling material, and then further open the hole on the other side. Etching 2
It is characterized in that it is subjected to a second etching, is penetrated, and is subjected to outer shape processing. The filling material layer is also referred to as an etching resistance layer.

[0009]

The lead frame manufacturing method of the present invention is configured as described above, and is used for manufacturing a lead frame which can secure the strength of the outer leads and can achieve a narrow pitch of the inner leads. It is possible to provide a manufacturing method from the frame outer shape processing to the plating process. As a result, it is possible to cope with further increase in the number of terminals and high integration of the semiconductor device. For details, in order,
The tip of the inner lead portion of the lead frame is connected by a connecting portion, and at least the inner lead tip is made thinner than the thickness of the lead frame material, and the outer lead portion and others are externally processed to the thickness of the lead frame material. Etching process, specifically, a predetermined resist pattern is provided on both sides of the lead frame material, and etching is performed by using this as an etching-resistant mask. After etching a predetermined amount without penetrating the frame material, stop the etching, fill the holes on one side of the manufactured lead frame material with an etching resistant filler, and then further etch the holes on the other side. Etching process that performs the second etching, penetrates, and processes the outer shape By having, it is possible to correspond to a narrow pitch of the inner leads, it is assumed that can ensure the strength of the outer lead. Further, by having a partial plating step in which the plating solution is sprayed using a masking jig on at least the inner lead tips of the lead frame that has been externally processed by connecting the tips of the inner lead sections with the connecting section, The deformation of the inner lead tip due to the pressing member is prevented so that the plating leakage is less likely to occur. Further, specifically, as a masking jig for plating, the non-plated portion is closely adhered to form a mask as a mask for a plating, the plated region of the inner lead portion is an opening, and the opening is To prevent the plating solution from splashing onto the plating area, use a material that is gradually narrowed toward the plating area side of the lead frame to prevent leakage of plating to unnecessary parts and to obtain the required inner lead tip. It is possible to attach the plating only to the narrow area.
Further, by providing the taping step of attaching the tape for fixing the inner lead portion, the inner lead is displaced (deflected) even after the step of cutting and removing the connecting portion that is unnecessary when manufacturing the semiconductor device. There is no.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a lead frame manufacturing method of the present invention will be described with reference to the drawings. FIG. 1 shows main steps of a method for manufacturing a lead frame of an embodiment, FIGS. 2 and 3 are process diagrams for explaining an etching process, and FIGS. FIG. 7 is a plan view of a lead frame manufactured by the lead frame manufacturing method of the present embodiment. In order to make the relationship between the lead frame manufacturing process and the semiconductor device manufacturing process easier to understand, the dotted line portion in FIG. 1 shows the semiconductor device manufacturing process. The present embodiment is a method of manufacturing a lead frame in which at least the inner lead tips are made thinner than the thickness of the lead frame material, and the thin portion is partially plated for wire bonding, as shown in FIG. A method of manufacturing a lead frame in which the tips of the inner leads are formed thinner than the other parts of the outer leads. Then, as shown in FIG. 1, the tips of the inner lead portions of the lead frame are sequentially connected by a connecting portion,
Further, an etching process (FIG. 1A) in which at least the inner lead tips are made thinner than the thickness of the lead frame material, and the outer leads and others are externally machined while maintaining the thickness of the lead frame material, and an etching process. Partial plating step of performing plating by spraying a plating solution using a masking jig on at least the inner lead tip of the lead frame that has been externally processed in the step (see FIG. 1).
(B)), a taping step of attaching a tape for fixing the inner lead portion (FIG. 1 (c)), and a step of cutting and removing the connecting portion connecting the tips of the inner lead portions (FIG. 1).
(D)) is included.

The etching process of the method for manufacturing the lead frame of this embodiment shown in FIG. 1 will be specifically described below with reference to FIG. 2A to 2D are cross-sectional views of the respective steps including the tip of the inner lead, which is a plan view showing the lead frame manufactured here. FIG. 2B is a manufacturing process drawing in the cross-sectional part of the A1-A2 portion of FIG. 7A. In FIG. 2, 210 is a lead frame material, 220A and 220B are resist patterns, 230 is a first opening, 240 is a second opening,
Reference numeral 250 is a first concave portion, 260 is a second concave portion, 270 is a flat surface, 280 is an etching resistance layer (filler layer), 71
Reference numeral 0 indicates the inner lead tip portion, 711 indicates the inner lead tip thin portion, and 711Ab and 711Aa indicate the etching flat surface and the lead frame material surface in the inner lead tip thin portion, respectively. First, after cleaning and degreasing both surfaces of a lead frame material made of a copper alloy and having a thickness of 0.15 mm, a PVA (polyvinyl alcohol) aqueous solution using potassium dichromate as a photosensitizer. After coating the resist consisting of the mixed solution of the above on both sides and drying the resist, each of the predetermined areas of the resist on both sides of the lead frame material is exposed using a predetermined pattern plate, and development processing is performed to form a first shape of the predetermined shape. Resist patterns 220A and 220 having openings 230 and second openings 240
B was formed. (FIG. 2 (a)) The first opening 230 is for etching the lead frame material 210 from the opening to a thinner thickness than the lead frame material 210 in a later etching process. The second opening 240 is for forming the shape of the tip of the inner lead. The first opening 230 includes at least the inner lead tip portion forming region of the lead frame, but is corroded in a solid shape and partially thinned in a taping step or a clamp step of fixing the lead frame in a later step. Since there is a case where the step difference with the open portion interferes, it is necessary to make the etching area large rather than only the finely processed portion of the tip of the inner lead. Then, using a ferric chloride solution with a liquid temperature of 50 ° C and a specific gravity of 46 Baume, a spray pressure of 3.0 kg.
At / cm ^2, the both surfaces of the leadframe material 210 on which a resist pattern is formed by etching, about the depth h of the first recess 250 which is corrosion solidly (flat) of the lead frame member 2/3 The etching was stopped when the degree reached. (FIG. 2B) Lead frame material 21 in the first etching
The reason for etching from both sides of 0 at the same time is to shorten the second etching time described below by etching from both sides. Compared with the case of single-sided etching only from the resist pattern 220B side, the first etching is performed. The total time for the second etching is shortened.

Then, a hot melt type wax having an etching resistance as an etching resistance layer 280 (corresponding to an acid wax manufactured by The Inktech Co., Ltd., model number MR) is formed in the corroded first recess 250 on the side of the first opening 230. -WB6)
It was applied using a die coater and embedded in the first recess 250 which was corroded into a solid (flat) shape. The resist pattern 220B was also applied to the etching resistance layer 280. (FIG. 2C) The etching resistance layer 280 is formed on the resist pattern 220B.
Although it is not necessary to apply it to the entire upper surface, it is difficult to apply it only to a part including the first concave portion 250.
As shown in ((c)), together with the first recess 250,
An etching resistance layer 280 was applied over the entire surface of the first opening 230 side. Etching resistance layer 280 used in this example
Is an alkali-soluble wax, but it is preferable that it is basically resistant to an etching solution and has some flexibility during etching. The wax is not particularly limited to the above wax, and a UV-curable wax may be used. As described above, the etching resistance layer 280 is embedded in the corroded first recess 250 on the surface on which the pattern for forming the shape of the inner lead tip portion is formed, so that the first recess is formed at the time of etching in a later step. 250 is not corroded and becomes large, and mechanical strength is reinforced for high-definition etching processing, and spray pressure can be made high (3.0 kg / cm ² ). This facilitates the etching to proceed in the depth direction. After that, the second etching is performed, and the lead frame material 2 is formed from the surface where the first recess 250 is formed which is corroded in a solid (flat) shape.
10 was etched and penetrated to form the inner lead tip thin-walled portion 711. (FIG. 2 (d)) The surface formed by the first etching process and parallel to the lead frame surface is flat, but the two surfaces sandwiching this surface are recessed toward the inner lead side. . Then, cleaning, removal of the etching resistance layer 280, and removal of the resist films (resist patterns 220A and 220B) were performed to obtain a lead frame 700 shown in FIG. 7 in which the inner lead tip thin-walled portion 711 was finely processed. (Figure 2
(E)) The etching resistance layer 280 and the resist film (resist patterns 220A and 220B) were removed by dissolution with a sodium hydroxide aqueous solution.

The etching method shown in FIG. 2 may be replaced by the processing method shown in FIG. The etching processing method shown in FIG. 3 is the same as the method shown in FIG. 2 until the first etching step, but after the etching resistance layer 280 is embedded in the second recess 260 side, the first recess 250 is formed. The difference is that the second etching is performed from the side and the etching is performed. However, the etching from the second opening 240 is sufficiently performed in the first etching.

The above-described etching processing method in which etching is divided into two steps is generally called a two-step etching processing method, and is a processing method particularly advantageous for fine processing. In manufacturing the lead frame shown in FIGS. 2 and 3 used in this embodiment, there are a two-step etching method and a method in which the lead frame material is partially thinned by devising the pattern shape to perform the outer shape processing. Is taken along with.

The miniaturization of the inner lead tip thin-walled portion 711 by the above-described method is performed by the shape of the second recess 260,
It depends on the thickness t of the finally obtained inner lead tip. For example, when the plate thickness t is reduced to 50 μm, the flat width W1 shown in FIG. Fine processing is possible up to a pitch p of 0.15 mm. If the plate thickness t is reduced to about 30 μm and the flat width W1 is set to about 70 μm, fine processing can be performed to the inner lead tip end pitch p of about 0.12 mm. However, depending on how to set the plate thickness t and the flat width W1, the inner lead The tip pitch p can be made to a narrower pitch.

Incidentally, in the etching process, FIG.
As shown in FIG. 8A, a connecting portion 713 is provided from the inner lead tip portion to obtain a shape in which the inner lead tip portions are connected to each other. As shown in FIG. 8B, for fixing at a predetermined position. Attach the resin tape 760,
After the plating process and the like, the connecting portion 713 unnecessary for semiconductor fabrication is cut and removed by a press or the like to obtain the shape shown in FIG. 8C.

Next, the plating process of this embodiment will be further described below with reference to FIG. In FIG. 4, 400 is a plating device, 410 is a lead frame, 411 is a thin portion of the inner lead, 412 is a plating region, 413 is a connecting portion, and 420
Is a masking jig, 420A is an opening, 430 is a sparger, 440 is a holding member, 450 is a positioning hole, 451
Is a positioning pin. In the plating process of FIG. 1 (b),
Opening 421 only on the part of the inner lead tip where plating is required
Using the masking jig 420 provided with the above, a sparger type plating device 40 that closely adheres to and covers a portion not requiring plating and sprays a plating solution onto a portion requiring plating by spraying from a nozzle.
0 is used for plating.

Lead frame 410 and masking jig 4
The positioning of the positioning pins 451 and 20 is performed by fitting the positioning pins 451 into the positioning holes 450. Masking jig 4
As shown in the development view of FIG.
21, a pattern side substrate 422, an intermediate substrate 423, and a sparger side substrate 424, all of which have a predetermined hole (positioning hole) 450 to be fitted with a positioning pin 451.
A, 450B, 450C, and 450D are provided, and the respective positioning is performed by fitting the holes with the positioning pins 451 and stacking them. As shown in FIG. 4, the lead frame 410 is placed on the pattern plate 421 of the masking jig 420 in such a stacked state, and is pressed by the pressing member 440 to bring the lead frame 410 and the pattern plate 421 into close contact with each other. Since the plating area 412 that requires plating is a narrow area of the inner lead thin portion 411, the opening 421 of the masking jig 420 is provided with a lead frame from the nozzle side that ejects the plating in order to make it easier for the plating solution to hit this area. The substrate 424 on the sparger side, the intermediate substrate 423,
The pattern side substrate 422 and the pattern plate 421 are provided with openings 424A, 423A, 423 and 421A shown in FIG. 5, respectively. Incidentally, the masking jig may be integrally formed as shown in FIG. In this case, the tip portions of the die pad 411 and the inner leads 412 of the lead frame are plated.

Next, a lead frame manufactured by the lead frame manufacturing method of the present invention will be described with reference to FIG. The lead frame 700 shown in FIG. 7 is manufactured by the above method for manufacturing a lead frame, and FIG. 7A is a plan view of the lead frame.
7B is a sectional view taken along line B1-B2 of FIG. 7A, and FIG. 7C is a sectional view of the thin portion of the inner lead tip. In FIG. 7, 700 is a lead frame, 71
0 is the inner lead, 711 is the thin portion of the inner lead tip, 711Aa is the first surface, 711Ab is the second surface, 720
Is a die pad, 730 is an outer lead, 740 is a dam bar, 750 is a frame portion, and 760 is a fixing tape. The display of the plated portion is omitted. As shown in FIG.
The thickness t of the thin portion 711 of the inner lead tip is 40 μm,
The thickness t ₀ other than the thin portion 711 at the tip of the inner lead is 0.
With the plate thickness of the lead frame material being 15 mm, the inner lead tip thin-walled portion 711 is provided with a silver-plated portion (not shown) for wire bonding with a semiconductor element (not shown). A tape 760 for fixing the inner lead 710 is provided on the thin portion 711 of the inner lead tip.
Is provided. A second fixing tape may be further provided at the positions C1 and C2. Further, the inner lead pitch is as narrow as 0.12 mm, which is adapted to the multi-terminal of semiconductor devices. The etching flat surface 711Ab of the inner lead tip thin-walled portion 711 is flat, and the etching surfaces 711Ac and 711Ad are recessed toward the inner lead side, which is strong in strength even if the wire bonding surface is narrowed.

Immediately after the outer shape processing by etching, FIG.
As shown in (a), the connecting portion 71 is attached to the tip of the inner lead.
The inner lead is fixed in the state where 3 is integrally provided to prevent the wrinkle. 8A and 8A show the case of the lead frame having the die pad shown in FIG.
(A) and (b) are enlarged views of the tips of the inner leads without the die pad. And FIG.
As shown in FIG. 8B, after plating, tapes 760 for fixing inner leads are attached respectively, and then, as shown in FIG.
As shown in FIG. 5, the connecting portion 713 is removed.

Further, in order to manufacture a semiconductor device using the lead frame manufactured by the method for manufacturing the lead frame of this embodiment, as shown by a dotted line portion in FIG. It goes through a bonding process, a resin sealing process, a dam bar cutting process, and a forming process.

[0022]

As described above, the lead frame manufacturing method of the present invention can manufacture a lead frame capable of coping with further increase in the number of terminals and density of a semiconductor device, from the lead frame outer shape processing to the plating step. It is possible to provide a manufacturing method.

[Brief description of the drawings]

FIG. 1 is a process diagram of a method for manufacturing a lead frame according to an embodiment.

FIG. 2 is a diagram of an etching process in the method for manufacturing the lead frame of the embodiment.

FIG. 3 is a diagram of an etching process in the method of manufacturing the lead frame of the embodiment.

FIG. 4 is a view for explaining a plating process in the lead frame manufacturing method of the embodiment.

[Figure 5] Development view of masking jig

FIG. 6 is a diagram for explaining another masking jig.

FIG. 7 is a diagram of a lead frame manufactured by the method for manufacturing a lead frame of the example.

FIG. 8 is a view for explaining the inner lead tip shape in the etching process.

FIG. 9 shows a conventional method for manufacturing a lead frame.

FIG. 10 is a view for explaining a conventional resin-encapsulated semiconductor device and a single-layer lead frame.

FIG. 11 is a view for explaining sparger type plating.

[Explanation of symbols]

210 Lead frame material 220A, 220B Resist pattern 230 First opening 240 Second opening 250 First recess 260 Second recess 270 Flat surface 280 Etching resistance layer (filler layer) 400 Plating machine 410 Lead frame 411 Inner lead thin portion 412 Plating area 413 Connecting portion 420 Masking jig 420A Opening 421A, 4122A, 423A, 424A Opening 430 Sparger 440 Holding member 450 Positioning hole 450A, 450B, 450C, 450D Hole 451 Positioning pin 700 Lead frame 710 Inner Lead 711 Inner lead tip thin-walled portion 711Aa Lead frame material surface 711Ab Etched flat surface 711Ac, 311Ad Etched surface 712 Plated portion 713 Connection part 720 Outer lead 730 Dam bar 740 Frame part 760 Fixing tape (resin tape) 910 Lead frame material 920 Photo resist 930 Resist pattern 940 Inner lead 1015 Frame part (frame part) 1010 Semiconductor element 1011 Terminal (pad) 1020 Lead frame 1021 Die pad 1022 Inner lead 1023 Outer lead 1024 Dam bar 1030 Wire 1040 Sealing resin 1110 Lead frame 1111 Inner lead 1111A No plating required part 1120 Masking jig 1120A Opening 1130 Spudger 1140 Holding member 1150 Positioning hole 1151 Positioning pin 1160

Claims (3)

[Claims] 1. A method of manufacturing a lead frame in which at least the inner lead tips are made thinner than the thickness of the lead frame material, and the thin portions are partially plated for wire bonding. Etching process in which the tips of the inner lead parts are connected by a connecting part, and at least the inner lead tips are made thinner than the thickness of the lead frame material, and the outer leads and other parts are externally processed to the thickness of the lead frame material. When,
Partial plating process in which the plating solution is sprayed using a masking jig on at least the inner lead tip of the lead frame that has been externally processed in the etching process to perform plating, and tape for fixing the inner lead part is taped. A method of manufacturing a lead frame, comprising: a step; and a step of cutting and removing a connecting portion that connects the tips of the inner lead portions. 2. The plating masking jig according to claim 1, wherein the non-plated portion is brought into close contact with the lead frame shape to form a mask, and the plated region of the inner lead portion is an opening, and the opening is formed. Is a method of manufacturing a lead frame, wherein the plating solution is gradually narrowed toward the plating area side of the lead frame so that the plating solution is easily applied to the plating area. 3. The etching process according to claim 1, wherein a predetermined resist pattern is provided on both sides of the lead frame material and etching is performed using this as an etching resistant mask. The first step is performed from one side or both sides of the lead frame material. Etching is performed by etching a predetermined amount without penetrating the lead frame material, and then etching is stopped, and an etching resistant filler is embedded in the hole on one surface of the produced lead frame material, and then the other surface A method of manufacturing a lead frame, characterized in that a second etching is performed to further etch the hole portion, the hole is penetrated, and the outer shape is processed.