TW200414479A - Method of manufacturing lead frame - Google Patents

Abstract

A method in which a raw material for a lead frame is used to manufacture a lead frame having a plating area, which is formed by a photometric method, at its recessed part and planar part other than the recessed part, wherein a resist layer which was used as a mask for etching is then used as a mask for plating.

Description

200414479 V. Description of the invention (1) [Technical field to which Ming belongs]. The method of the present invention relates to a method for manufacturing a lead frame, and particularly to the recesses carved by money by the method of photometry (ph 〇t 〇in etric) A method for manufacturing a lead frame which is not plated with a portion of the engraved portion. [Prior art] ^ As one of the components for mounting semiconductor elements, the lead frame is mainly composed of a wafer mounting portion on which a semiconductor element is mounted, and is provided on the surface of the semiconductor element.

The electrode portion of L is composed of an inner lead portion which is electrically connected and an outer lead portion where the semiconductor element and the circuit substrate are bonded after being assembled. Φ The manufacturing method of high-density leadframes that have been affected by the miniaturization of electronic equipment to date has been a method of etching. For example, a photoresist layer composed of a photosensitive resist is provided on the surface of the material for the lead frame, and a mask having a desired pattern is adhered thereto, exposed and developed to obtain a mask for etching. An exposed portion of the lead frame material is etched, and then the remaining etching mask made of a photoresist layer is removed, and then a necessary portion is plated to obtain a lead frame. At the moment, the electric power ore is considered in order to obtain good wire bonding (w i r e b ο n d i n g) and other factors. For example, when the material is copper, the key recorder, the handle, and the bell gold are sequentially performed.

• A lead frame for BCC (Bump C 1 ip C arrier), which is one of the lead frames of this type, is a recess formed on the lead frame material by the aforementioned etching method to form an electrode portion and a chip mounting portion. A required portion of the recess is provided with a plating layer having a dissolution property different from that of the material for the lead frame. Use BCC

314355.pul Page 6 200414479 V. Description of the Invention (2) When a lead frame (first image (A)) is used, as shown in the first images (A) to (D), a semiconductor is mounted in a concave chip mounting portion. Device, the electrode portion of the semiconductor device surface and the inner surface of the concave electrode portion are wire-bonded (first image (B)), and then resin-sealed (first image (C)), followed by dissolving and removing the lead frame material (first (D)). Therefore, the package size using the BCC lead frame can be reduced compared to other packages. In this type of BCC lead frame, when the wafer mounting portion has both a concave portion and a flat portion, a flat portion other than the concave portion may be plated. In this case, the photoresist layer used as a mask for etching cannot be directly used as a mask for electroplating. Once peeled, a photoresist layer needs to be provided again, and exposure and development are performed with a desired mask to obtain plating. Then, the exposed portion of the lead frame material is plated, and then the plated mask is removed. Due to the numerous procedures, BCC lead frames are more expensive than other packages. Although they have advantages in package size, they are difficult to use widely. [Summary of the Invention] Technical Problem to be Solved by the Invention An object of the method of the present invention is to provide a method for solving the above-mentioned problems and producing a lead frame having a key region on a concave portion and a portion other than the concave portion at a low cost. Technical means for solving the problem One aspect of the method for manufacturing the lead frame of the present invention is to use a photometric method having the following steps to make the first region defined by the first mask into a concave portion by etching, and use The method including the first area is used to mine the second area defined by the second mask.

3] 4355.ptd Page 7 200414479-V. Description of the invention (3) (1) The step of providing a photoresist layer on the surface of the material for the lead frame; (2) Adhering the first mask to the surface and performing the first exposure method Step of exposing (3) removing the first mask, closely contacting the second mask, and performing exposure in the second exposure mode; (4) removing the second mask, developing in the first development mode, and forming For example, a step of etching a mask made of a photoresist layer in the first region; (5) a step of forming a concave portion by etching the material of the lead frame exposed from the mask for etching; (2) a step of performing development in a two-phenomenon manner to form a plating mask made of a photoresist layer as a second region; and (7) a step of plating the lead frame material exposed from the plating mask and borrowing The photoresist layer can be removed by the first exposure method, the second exposure method, and the first development method, and the photoresist layer can be left by the second exposure method and the first development method. The developing method and the second developing method can remove the photoresist layer. In another aspect of the method for manufacturing a lead frame of the present invention, the first region specified by the first mask is etched into a concave portion by a photometric method having the steps shown below, and the first region is included in the first region. The area mode performs electrical keying on a second area defined by the second mask. (1) the step of providing a first photoresist layer on the surface of the material for the lead frame, and providing a second photoresist layer having a lower sensitivity than the first photoresist layer on the first photoresist layer; (2) closely contacting the first mask on the surface Hood, the first exposure step

314355.ptd Page 8 200414479 V. Description of the invention (4) Steps; (3) Remove the first mask, close the second mask, and perform the exposure in the second exposure mode; (4) Remove the second mask A step of developing a mask in a first developing manner to form an etching mask made of a photoresist layer as in the first region; (5) performing a process for the lead frame material exposed from the etching mask; A step of etching to form a concave portion; (6) a step of developing in a second developing mode to form a plating mask made of a photoresist layer as a second region; and (7) a step for forming a mask from the plating The exposed lead frame material is subjected to a plating process, and the first photoresist layer and the second photoresist layer can be removed by the first exposure method, the second exposure method, and the first development method. In the exposure mode and the first phenomenon mode, the second photoresist layer is removed to leave the first photoresist layer. The first photoresist layer can be removed by the second exposure mode, the first development mode, and the second development mode. In another aspect of the method for manufacturing a lead frame of the present invention, a mask having a first transparent pattern, a semi-transparent second pattern, and a third pattern that blocks light is juxtaposed by the steps shown below. In the photometric method, the first region defined by the light transmitted through the first pattern is made into a concave portion by the etching method, and the second region defined by the light transmitted through the second pattern is plated. (1) a step of providing a photoresist layer composed of a positive photoresist on the surface of the material for the lead frame; (2) a step of closely contacting a mask on the surface, exposing, and removing the mask;

314355.ptd Page 9 200414479 V. Description of the invention (5) (3) The step of developing by the first developing method to form an etching mask formed by a photoresist layer as in the first region; (4- ) A step of forming a concave portion by etching the lead frame material exposed from the etching mask; (5) developing in a second development mode to form a photoresist layer as a second region A step for plating a mask; and (6) a step for plating a lead frame material exposed from the mask for gold plating, and removing the resist layer by exposing the first region and the first development method. The photoresist layer is left by the exposure to the second area and the first development method. The photoresist layer can be removed by the exposure to the second area, the first development method, and the second development method. The third area where the pattern blocks light is left. In another aspect of the method for manufacturing a lead frame of the present invention, a mask having a first transparent pattern, a semi-transparent second pattern, and a third pattern that blocks light is juxtaposed by the steps shown below. In the photometric method, a third region that shields light by a third pattern is made into a concave portion by an etching method, and is plated, and a second region defined by light transmitted through the second pattern is plated. 1) The cost of providing a photoresist layer composed of a negative photoresist on the surface of the material for the lead frame; (2) the steps of closely contacting the mask on the surface, exposing and removing the mask; (3) developing with the first image A method of performing development to form an etching mask made of a photoresist layer as in the third region; (4) etching the lead frame material exposed from the etching mask;

314355.ptd Page 10 200414479 V. Description of the invention (6) Steps of forming a concave portion; (5) Developing in a second development mode to form a photoresist layer composed of a photoresist layer in the second area A masking step; and (6) a step of plating the lead frame material exposed from the plating mask, and removing the photoresist layer by the first developing method, and An imaging method makes the photoresist layer remain. The photoresist layer can be removed by exposing the second area, the first developing mode, and the second developing mode, and by exposing the first area and the first development. Mode and the second development mode, leaving the photoresist layer. In another aspect of the method for manufacturing a lead frame of the present invention, the first area defined by the first part of the mask is made by the photometric method using the mask having the first part and the second part by the steps shown below. The recessed portion is formed by the etching method, and the second region defined in the second part is clocked by including the first region. (1) a step of providing a photoresist layer on the surface of the material for the lead frame; (2) a step of exposing the first portion of the mask to the surface in a first exposure manner; (3) a step of closely contacting the mask in the first region The second part is the step of performing exposure in the second exposure mode; (4) the step of developing in the first development mode to form a mask for etching, which is formed by a photoresist layer in the first area; (5) borrowing A step of forming a concave portion by etching the lead frame material exposed from the etching mask;

314355.ptd Page 11 200414479 V. Description of the invention (7) Γ6) The step of developing by the second developing method to form a plating mask composed of a photoresist layer 'in the second region; and (7- ) The step of plating the lead frame material exposed from the plating mask, and removing the photoresist layer by the first exposure method, the second exposure method, and the first development method, and using the second exposure method and The first development method makes the photoresist layer remain, and the photoresist layer can be removed by the second exposure method, the first development method, and the second development method. Another aspect of the manufacturing method of the lead frame of the present invention is to use the steps shown in i # F to use the photometric method of the mask with the first part and the second part juxtaposed to make the The first region becomes a concave portion by an etching method, and the second region defined in the second portion is plated so as to include the first region. (1) a step of providing a photoresist layer on the surface of the lead frame material; (2) a step of closely contacting the first part of the mask on the surface and a step of exposing; (3) a step of closely contacting the second part of the mask in the first area by moving The mask is a step of sequentially exposing the first part of the mask in close contact with the other surface part of the material for the lead frame, and sequentially exposing in this manner; (4) performing the development in the first development mode to form the first area. A step of etching a mask made of a photoresist; (5) a step of etching and forming a concave portion of the lead frame material exposed from the etching mask; (6) performing a second development method Image, a step of forming a plating mask made of a photoresist layer like the second region; and

314355.ptd Page 12 200414479 V. Description of the invention (8) (7) The step of plating the lead frame material exposed from the plating mask, and it can be removed by double exposure and first development method In the photoresist layer, the photoresist layer is left in one exposure and the first development mode, and the photoresist layer can be removed by one exposure, the first development mode, and the second development mode. It is also preferable to form a photoresist layer that is not sensitive to light during exposure to or near the etching area and the plating area. [Embodiment] In the first state of the method of the present invention, the positional relationship between the material for the lead frame, the mask, and the photoresist layer with different oblique lines indicating the change in the photosensitive state is as shown in the second figure (A) to ( C) is shown as a continuous cross-sectional view. That is, a photosensitive photoresist layer is provided on the surface of the material for the lead frame (second image (A)), and firstly exposed using a mask having a desired etching photoresist pattern (second image (B)), and then using A mask with a plating pattern is exposed (second image (C)). As a result, the photoresist layer corresponding to the etched portion may be easily opened even under mild developing conditions, and does not correspond to the etched portion. The photoresist layer corresponding to the plated portion is only developed after a stronger developing condition. May speak. The essence of the present invention is to use this result. Specific exposure conditions and development conditions are not particularly limited because they depend on the material used to form the photoresist layer. If necessary, it is ideal to obtain the prerequisites for implementation in advance. The usable photoresist can be a photosensitive photoresist or a thermal photoresist; its shape is also a film or a liquid. The second pictures (D) to (G) show the post-processes of development, etching, second development, and plating.

314355.ptd Page 13 200414479 V. Description of the invention (9) \ In the second aspect of the method of the present invention, the material for the lead frame, the shield, the cover, and the photoresist layer with different oblique lines indicating the change of the photosensitive state The positional relationship is shown in FIG. 3 (A) and (B) by continuous cross-sectional views. 1, that is, the exposure levels are separated in stages (Fig. 3 (B)), and in the first development process, the photoresist position corresponding to the portion to be etched is opened. However, after that, a second development process is performed after the etching. At this time, the light and resist layers of the portion corresponding to the portion to be plated are removed except for the portion corresponding to the portion to be etched. The photoresist layer in this part will remain in the first development process due to insufficient light transmission. The # must be completely removed in the second development process. Therefore, this part functions as an etching mask after the first development. In this case, specific exposure conditions and development conditions are not particularly limited because they depend on the material used to form the photoresist layer. If necessary, it is better to obtain conditions before implementation. The usable photoresist can be a photosensitive photoresist or a thermal photoresist; its shape is also the same, which can be a film or a liquid. Figures 3 (C) to (F) show post-processing steps of development, etching, second development, and plating. Moreover, in the third aspect of the method of the present invention, the position of the lead frame material, the mask, and the position of the photoresist layer in which the change in the photosensitive state is represented by different oblique lines. The relationship is as shown in Figs. 4 (A) to (D). ), Shown as a continuous cross-sectional view. • That is, as a photoresist layer provided on the surface of the lead frame material, a high-sensitivity photoresist is placed on the side of the lead frame material (Fig. 4 (A)), and a general photoresist is placed on the outside. A negative photoresist obtained by bonding a photoresist layer (Fig. 4 (B)). On the photoresist layer thus obtained, a first mask is attached and then exposed (Fig. 4 (C)), and then a second Mask re-exposure (Figure 4 (D)).

314355.ptd Page 14 200414479 V. Description of the Invention (10) By this, because the part to be etched is not sensitive, it is easy to open. However, since the photoresist layer of the plated portion other than the portion to be etched receives only one exposure, it will remain in the initial development and fully function as a mask for etching. However, the remaining photoresist layer of the portion to be plated is removed in the second development to form a mask for plating. In this case, specific exposure conditions and development conditions are not particularly limited because they depend on the material used to form the photoresist layer. The first development and the second development may be under the same conditions or different conditions. If necessary, it is better to obtain conditions before implementation. The available photoresist is ideal for laminating film-shaped photoresistors in operation, but liquid photoresists are not necessary. In another aspect of the method of the present invention, for example, a photoresist layer is provided on the surface of the lead frame material, and a first portion is masked with a first portion having a desired etching pattern and a second portion having a desired plating pattern. The surface of the photoresist layer is closely contacted and exposed, and then the lead frame material is sent out. In order to overlap the plating pattern at a predetermined position on the etching pattern, the second part is aligned with the position of the lead frame material and exposed again. Repeat this operation in order. The photoresist layer corresponding to the etched portion can be easily opened even under mild developing conditions, and does not correspond to the etched portion. The photoresist layer corresponding to the plated portion is opened after stronger developing conditions. The essence of the present invention is to use this method for exposure and development. In the foregoing aspect, regarding the positional relationship of the photoresist layer, changes in the material of the lead frame, the mask, and the photosensitive state are indicated by different oblique lines.

314355.ptd Page 15 200414479 V. Description of the Invention (11) ^ In the present invention, the specific exposure conditions and development conditions depend on the materials used, and therefore are not particularly limited. If necessary, it is better to obtain the conditions before implementation. Regarding the exposure method, the first part and the second part may be separately exposed, or the plural first parts and the plural second parts may be exposed at one time. ‘A usable photoresist can be a photosensitive photoresist or a thermal photoresist; its shape is the same, it can be a film or a liquid. -Also, in other aspects, the material for the lead frame, the mask, the photoresist layer with different oblique lines representing the change in the light-sensitive state, and the completely insensitive light in the exposed light | and the positional relationship between the layers is as shown in Figure 5 ( A) to (C) are shown in continuous cross-sectional views. That is, when the second part of the electro-mineral pattern with a promising pattern is exposed, the exposure is performed in order to maintain a good completed state in the two subsequent developments and to ensure the size of the plated area easily. The medium-insensitive photoresist layer field is formed at or adjacent to the pattern formed by the mask (Fig. 5 (D)), which can also be effectively used in the practice of the present invention. Examples The method of the present invention will be described below with examples. ^ Example 1 ® is explained with reference to the continuous sectional views shown in the second figures (A) to (G). A copper sheet material with a thickness of 0.125 mm, a width of 35 mm, and a length of 150 mm is used as the material for the lead frame, and a photoresist layer (made by Asahi Kasei Co., Ltd., trade name: AQ-2558) is provided on the surface. The openings for forming the concave bottom and the diameters equally arranged on both sides of the concave bottom

314355.pid Page 16 200414479 V. Description of the invention (12) 0 · 0 7 5 mm, a total of 2 5 5 First masking ceremony for forming a pattern of an opening portion of a concave electrode pad portion Connect to the surface of the photoresist layer and irradiate 30 m J of ultraviolet rays. Next, the first mask is removed, and four openings having a side of 2 2Π11111 for plating on the concave bottom and a diameter of 0 · 0 8 〇_ which are evenly arranged on both sides of the concave bottom are provided, totaling A second mask of 2 5 5 patterns for opening portions for plating the concave electrode pad portion was closely adhered to the surface of the photoresist layer and irradiated with ultraviolet rays of 1 OmJ.

Next, the second mask 'was removed and immersed in a sodium carbonate solution for 40 seconds to develop a light layer to prepare a mask for I insect engraving. Then, half of the surface portion of the exposed lead frame material is engraved to make a concave bottom portion and a concave electrode pad portion. Next, it was immersed in a sodium carbonate solution for 80 seconds to re-image the photoresist layer to obtain a mask for power mining. Then, the surface portion of the lead frame material exposed from the electroplating mask is subjected to gold strike plating, followed by a bond layer having a thickness of 1 " m, and a bond nickel layer having a thickness of 6 // πm and It is the plating layer with the average thickness of the outermost layer 1 // m. Thus, a BCC lead frame is formed. In this embodiment, it takes 5 hours to manufacture 1,000 lead frames. Next, semiconductor components were mounted using the lead frame for BCC thus obtained, and 500 BCCs were fabricated. The dissolved BCC was reflowed by soldering (refl test). As a result, no conduction occurred.

And remove the lead frame material. The obtained ωw) was mounted on a printed wiring board, and the conduction failure was performed. Description is made with reference to FIGS. 6 (A) to (jw-J).

Page 17 200414479 V. Description of the invention (13) ~ Use copper sheet with thickness of 0.125mm, width of 35mm, and length of 150mm as the material for the wire-frame, and a photoresist layer (made by Asahi Kasei Corporation, trade name: AQ- 2558), will be provided with four sides with a side of 20mm to form a concave bottom, and a diameter of 0.05 mm equally arranged on both sides of the concave bottom, a total of 255 to form a concave shape The first mask of the pattern of the opening portion of the electrode pad portion was in close contact with the surface of the photoresist layer and irradiated with ultraviolet rays of 80 mJ. Next, the first mask was removed and immersed in a sodium carbonate solution for 40 seconds to develop a photoresist layer to obtain a mask for etching. Then, the surface of the exposed lead frame material is half-etched to make a concave bottom and a concave electrode pad. Next, a mask for etching is removed, and a photoresist layer (manufactured by Asahi Kasei Co., Ltd., trade name: AQ- 2 5 5 8) is provided on the surface of the material for the lead frame, and four recesses with a side of 2 2 mm are provided for the concave shape. The bottom and the second mask alignment position of the pattern of the opening portion for plating the concave electrode pad portion with a diameter of 0.080 mm equally arranged on both sides of the concave bottom portion are in close contact. The surface of the photoresist layer was irradiated with 80 mJ of ultraviolet rays. Next, the second mask was removed and immersed in the sodium carbonate solution for 40 seconds to develop a photoresist layer to prepare a mask for electroplating. Then, gold plating is performed on the exposed surface of the lead frame material, and then a palladium plating layer with a thickness of 1 // m is set. Then, the plating layer with a thickness of 6 // m and the average thickness of the outermost layer 1 // m Of the mine I bar. Thus, a BCC lead frame is formed. In this conventional example, it took 8 hours to manufacture 1,000 lead frames. Evaluation of the same continuity test as in Example 1 was performed, and as a result, no poor conduction occurred.

3] 4355.ptd Page 18 200414479 1 V. Description of the Invention (14) Embodiment 2 Refer to the continuous sectional views shown in Figures 4 (A) to (Η). A copper sheet with a thickness of 0.125 mm, a width of 35 mm, and a length of 150 mm was used as the material for the lead frame. A high-sensitivity photoresist film (manufactured by Hitachi Chemical Co., Ltd., LF 1 4 1 0) was laminated on the surface, and then it was generally laminated thereon. A photoresist film (manufactured by Asahi Kasei Co., Ltd., trade name: AQ-2 5 5 8) is provided with a photoresist layer. Next, there are provided four recessed bottoms having a side of 20 mm, and a diameter of 0. 0 0 mm equally arranged on both sides of the recessed bottom, for a total of 2 5 5 to form a recessed shape. The second mask of the pattern of the opening portion of the electrode pad portion is in close contact with the surface of the photoresist layer and exposed. Next, removing the second mask, there will be provided four with a side of 2 Omm for the concave bottom, and a diameter of 0. 0 7 5mm equally arranged on both sides of the concave bottom, a total of 2 2 5 A first mask of a pattern of an opening portion for electroplating the concave electrode pad portion was closely adhered to the surface of the photoresist layer and irradiated with 30 mJ of ultraviolet rays. Next, the first mask was removed and immersed in a sodium carbonate solution for 40 seconds to develop a photoresist layer to prepare a mask for etching. Then, the surface portion of the exposed lead frame material is half-etched to make a concave bottom and a concave electrode pad portion. Then, immersed in a sodium carbonate solution for 40 seconds to make the photoresist layer develop again. A mask for electroplating was obtained. Then, the exposed surface portion of the lead frame material is subjected to gold plating, followed by a plated layer with a thickness of 1 // m, and a nickel plated layer with a thickness of 6 // m, and an average thickness of 1 / m as the outermost layer. Full of minerals. Thus, a lead frame for BCC is formed. In this embodiment, it takes 6 to manufacture 1,000 lead frames.

314355.ptd Page 19 200414479 V. Description of the invention (15) Small'-hour. \ The same continuity test evaluation as in Example 1 was performed, and as a result, no poor continuity occurred. Embodiment 3 is explained with reference to the continuous sectional views shown in FIGS. 3 (A) to (F). • Use a copper sheet with a thickness of 0.125mm, a width of 35mm, and a length of 150mm as the material for the wire @ frame. A photoresist layer (made by Asahi Kasei Corporation, trade name: AQ-2558) is formed on the surface of the material. It is provided with: four having a side of 20 Hi m to form a concave bottom, and 6 # ^ diameter 0. 0 7 5 mm equally arranged on both sides of the concave bottom, a total of 2 2 5 for forming a concave White pattern of ultraviolet light transmission at the opening of the electrode pad portion; gray pattern of 30% transparent of 1 mm width of ultraviolet rays at the concave bottom and outer peripheral portion of the concave electrode pad portion; and A mask of a black pattern capable of blocking ultraviolet rays is closely attached thereto, and irradiates ultraviolet rays of 80 mJ. Next, it was immersed in a sodium carbonate solution for 40 seconds to develop a photoresist layer and prepare a mask for etching. Then, the surface portion of the exposed lead frame material is half-etched to form a concave bottom portion and a concave electrode pad portion. Next, immersed in a sodium carbonate solution for 80 seconds, the photoresist layer was developed again, and a mask for electroplating was found. Then, the exposed surface portion of the lead frame material is subjected to gold plating, and then a palladium plated layer having a thickness of 1 // Ι ，, a plated layer having a thickness of 6 // m, and an average thickness of 1 / are used as the outermost layer. m plating period. Thus, a lead frame for BCC is formed. In this embodiment, it takes 6 hours to manufacture 1,000 lead frames. The same continuity test evaluation as in Example 1 was performed, but no scab occurred.

314355.ptd Page 20 200414479 V. Description of the invention (16) The communication is bad. Embodiment 4 is explained with reference to the continuous sectional views shown in the second figures (A) to (G). A copper sheet with a thickness of 0.125mm, a width of 35mni, and a length of 150mm is used as the material for the lead frame, and a photoresist layer (made by Asahi Kasei Corporation, trade name: AQ- 2 5 5 8) is provided on the surface. It is the first part of a pattern of 20 mm for forming a concave bottom, and a diameter of 0.3 mm equally arranged on both sides of the concave bottom, for a total of 2 2 5 for forming an opening of a concave electrode pad portion, And provided with four having a side of 20 mm for the concave bottom, and a diameter of 0.4 mm equally arranged on both sides of the concave bottom, a total of 2 2 5 for the concave electrode pad portion The mask alignment position of the second part of the pattern of the plated opening part is arranged in close contact with the surface of the photoresist layer. Firstly, the first part is exposed to ultraviolet light of 80 m J, and then the sheet alignment position is moved. Two parts were exposed to ultraviolet light of 10 m J. The alignment position and exposure are performed in order. Next, the mask was removed, and the photoresist layer was developed by being immersed in a sodium carbonate solution for 60 seconds to prepare a mask for etching from which the photoresist layer to be etched was removed. Then, the surface portion of the exposed lead frame material is half-etched to form a concave wafer mounting portion and a concave electrode pad portion. Next, the photoresist layer was re-developed by being immersed in a sodium carbonate solution for 120 seconds to obtain a mask for electroplating from which a photoresist layer to be plated was removed. Then, the exposed surface portion of the lead frame material is plated with gold, followed by a key layer with a thickness of 1 // m, and a plated layer with a thickness of 6 // m and an average thickness of 0.5. / m of ore button layer. Thus, a BCC lead frame is formed. In this

314355.ptd Page 21 200414479 V. Description of the invention (17) f In the example, it takes 8 hours to manufacture 1,000 lead frames. — The same continuity test evaluation as in Example 1 was performed, and as a result, no poor continuity occurred. Conventional Example 2 is explained with reference to the continuous sectional views shown in FIGS. 6 (A) to (J). 1 A copper sheet with a thickness of 0.125mm, a width of 35mm, and a length of I50mm is used as the material for the guide and wire frame. A photoresist layer (made by Asahi Kasei Corporation, trade name Hachi AQ-2558) will be provided on the surface. It is 20mm to form a concave bottom, and a diameter of 0.3mm equally arranged on both sides of the concave bottom, a total of # 2 2 5 are the first to form a pattern of the opening portion of the concave electrode pad portion. The mask was closely adhered to the surface of the sheet, and was irradiated with 80 mJ of ultraviolet rays. Next, the first mask was removed and immersed in a sodium carbonate solution for 60 seconds to develop a photoresist layer to prepare a mask for etching. Then, the surface portion of the exposed lead frame material is half-etched to form a concave wafer mounting portion and a concave electrode pad portion. Next, a mask for etching is removed, and a photoresist layer (made by Asahi Kasei Co., Ltd., trade name: AQ-2558) is provided on the surface of the lead frame material, and four recessed wafer mounting portions having a side of 2 2 mm are provided. And the second mask alignment position of the pattern of the opening portion for plating the concave Θ electrode pad portion with a diameter of 0.4 mm and a diameter of 0.4 mm evenly arranged on both sides of the concave chip mounting portion is tightly sealed. The surface of the photoresist layer was irradiated with 80 mJ of ultraviolet rays. Next, the second mask was removed and immersed in a sodium carbonate solution for 60 seconds to develop a photoresist layer to obtain a mask for electroplating. Then, the surface portion of the exposed lead frame material is underplated with gold, and then a plating layer with a thickness of 0.1 / 1 m is provided,

314355.ptd Page 22 200414479 V. Description of the invention (18) A plating layer with a thickness of 6 // m and a palladium plating layer with an average thickness of 0.5 // m as the outermost layer are further provided. Thus, a BCC lead frame is formed. In this comparative example, it took 12 hours to manufacture 1,000 lead frames. Evaluation of the same continuity test as in Example 1 was performed, and as a result, no poor conduction occurred. [Effects of the Invention] In the method of the present invention, the photoresist layer formed at one time can be used sequentially as a mask for etching and a mask for electroplating, thereby saving operating materials. In addition, because the steps can be shortened, it is possible to provide a lead frame that is cheaper than conventional methods.

314355.ptd Page 23 200414479 Simple description of type B _ simple description of type] \ The first figures (A) to (D) are cross-sectional views showing the manufacturing steps of electronic parts using conventional lead frames. The second figures (A) to (G) are sectional views showing one aspect of the manufacturing steps of the method for manufacturing the lead frame of the present invention. Figures 3 (A) to (F) are sectional views showing manufacturing steps of another aspect of the manufacturing method of the lead frame of the present invention. (4) (A) to (Η) are sectional views showing manufacturing steps of another aspect of the manufacturing method of the lead frame of the present invention. Figures 5 (A) to (G) are sectional views showing manufacturing steps of another aspect of the manufacturing method of the lead frame of the present invention. Figures 6 (A) to (J) are sectional views showing the manufacturing steps of a conventional lead frame.

314355.ptd Page 24

Claims (1)

200414479 VI. Scope of patent application 1. A method for manufacturing a lead frame, which uses a photometric method to make a first area defined by a first mask into a concave portion by a last name engraving method. The manufacturing method of the lead frame for electroplating the second area specified by the second mask so as to include the first area includes: (1) a step of providing a photoresist layer on the surface of the lead frame material; (2) in The step of closely contacting the first mask on the surface and performing exposure in the first exposure mode; (3) removing the first mask, closely contacting the second mask and performing exposure in the second exposure mode; (4) removing the second A mask, which is developed in a first development mode to form an etching mask made of a photoresist layer as in the first region; (5) using a material for the lead frame exposed from the etching mask A step of performing etching to form a concave portion; (6) a step of developing in a second phenomenon to form a plating mask made of a photoresist layer as a second region; and (7) a step of plating from It is performed on the material of the lead frame exposed with a mask In the step of electricity mining, the photoresist layer can be removed by the first exposure method, the second exposure method, and the first development method, and the photoresist layer can be left by the second exposure method and the first phenomenon method. The two exposure methods, the first development method, and the second development method can remove the photoresist layer. 2. A method for manufacturing a lead frame, which uses the photome tr i c method to make the first area specified by the first mask engraved by an insect. 314355.ptd Page 25 200414479 VI. Method for manufacturing a lead frame that becomes a concave part and covers the second area defined by the first area in a manner that includes the first area, including- : (1) the step of providing a first photoresist layer on the surface of the material for the lead frame, and then providing a second photoresist layer having a lower sensitivity than the first photoresist layer on the first photoresist layer; (2) closely contacting the surface with the first photoresist layer; A mask, performing the steps of exposure and light in the first exposure mode; (3) removing the first mask, closely contacting the second mask, and performing the exposure in the second exposure mode; (4) removing the first Two masks, developing in the first development mode to form an etching mask made of a photoresist layer as in the first region; (5) using the lead frame exposed from the etching mask A step of etching the material to form a concave portion; (6) a step of developing in a second developing mode to form a mask for electroplating composed of a photoresist layer as a second area; and (7) a step of The step of plating the lead frame material exposed by the plating mask, and borrowing The first exposure method, the second exposure method, and the first development method can remove the first photoresist layer and the second photoresist layer, and the second photoresist layer is removed by the second exposure method and the first phenomenon method. The first photoresist layer is left, and the first photoresist layer can be removed by the second exposure method, the first development method, and the second development method. 3. —A method for manufacturing a lead frame, which is provided with light transmission by using 314355.ptd Page 26 200414479 6. The photometric method of the first pattern, the second translucent pattern, and the third pattern that shields light in the scope of the patent application. A manufacturing method of a lead frame in which a first region becomes a concave portion by etching and is plated on a second region defined by light transmitted through a second pattern includes: (1) a positive type is provided on a surface of the lead frame material; Steps of a photoresist layer composed of a photoresist; (2) Steps of closely contacting a mask on a surface, exposing, and removing the mask; (3) developing in a first development mode to form a photoresist in the first region A step of forming a mask for etching; (4) a step of forming a concave portion by etching the material for the lead frame exposed from the mask for etching; (5) developing by a second developing method A step of forming a plating mask made of a photoresist layer as in the second region; and (6) a step of plating the lead frame material exposed from the plating mask, and by Exposure and first development mode, can The photoresist layer is removed, and the photoresist layer is left by the exposure to the second area and the first development method. The photoresist layer can be removed by the exposure to the second area, the first development method, and the second development method. And there are survivors in the third area where the light is blocked by the third pattern. 4. A method for manufacturing a lead frame, which uses a photometric method using a mask in which a light-transmitting first pattern, a light-transmitting second pattern, and a light-shielding third pattern are juxtaposed. 3 patterns that block light 314355.ptd Page 27 200414479-VI. Scope of patent application i The third area is made into a concave part by etching and electroplated, and the lead frame is electroplated on the second area defined by the light transmitted through the second pattern The method includes: (1) a step of providing a photoresist layer composed of a negative photoresist on the surface of the material for the lead frame; (2) a step of closely sealing, exposing, and removing the mask on the surface; (3) using The first development method performs development to form an etching mask made of a photoresist layer as in the third region; (4) etching the lead frame material _ exposed from the etching mask, A step of forming a concave portion; (5) a step of developing in a second development mode to form a plating mask made of a photoresist layer as a second region; and (6) a mask from the plating The exposed lead frame material is subjected to a plating step, and the photoresist layer can be removed by the first development method, and the photoresist layer is left by the exposure to the second region and the first development method, and the second region is removed by the first development method. Exposure, first development mode and second development mode The photoresist layer can be removed, and the photoresist layer can be left by exposing the first area, the first development mode, and the second development mode. The manufacturing method of both types of lead frames is to use a photometric method using a mask having a first part and a second part to make the first region defined by the first part of the mask into a concave part by etching. The manufacturing method of the lead frame for plating the second area specified in the second part in a manner including the first area includes: 314355.ptd Page 28 200414479 6. Scope of patent application. (1) the step of providing a photoresist layer on the surface of the material for the lead frame; (2) the step of exposing the first part of the mask to the surface in a first exposure manner ; (3) a step of exposing the second part of the mask in the first area in a second exposure mode; (4) developing in a first development mode to form a photoresist layer as in the first area A step of forming a mask for etching; (5) a step of forming a concave portion by etching the material for the lead frame exposed from the mask for etching; (6) developing in a second development method, A step of forming an electric mining mask composed of a photoresist layer as the second region, and (7) a step of plating the lead frame material exposed from the plating mask, and by the first exposure method, The second exposure method and the first development method can remove the photoresist layer, use the second exposure method and the first development method to leave the photoresist layer, and use the second exposure method, the first development method, and the second The development mode can remove the photoresist layer. 6. A method for manufacturing a lead frame, which uses a photometric method of a mask in which a first part and a second part are juxtaposed, so that a first area defined by the first part of the mask is made concave by an etching method. And a method for manufacturing a lead frame for electroplating the second area specified in the second part in a manner including the first area, including: (1) a step of providing a photoresist layer on the surface of the lead frame material; (2) The first part of the mask is adhered to the surface and the exposure step is performed; 314355.ptd Page 29 200414479-Sixth, the scope of patent application i (3) close the second part of the mask in the first area, and move to cover the pain. The cover makes the first part of the mask close to the other of the material of the lead frame. A surface-surface part is exposed, and the steps of exposure are sequentially performed in this manner; (4) a step of developing in a first developing mode to form a mask as a first name composed of a photoresist layer (5) a step of etching and forming a concave portion of the material for the lead frame exposed from the mask for etching; (6) developing in a second developing mode to form a second region; A step of plating a mask made of a photoresist layer; and (7) a step of plating a lead frame material exposed from the plating mask, and by two exposures and a first development method, The photoresist layer is removed, and the photoresist layer is left in one exposure and the first development mode, and the photoresist layer can be removed by one exposure, the first development mode, and the second development mode. 7. The method for manufacturing a lead frame according to item 6 of the patent application, wherein a photoresist layer that is insensitive to light during exposure is formed at or adjacent to the etching area and the plating area. 314355.ptd Page 30