JPS6013304B2 - Manufacturing method of lead frame with support - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a lead frame with a support.

Lead frames with supports are usually made by drilling necessary through holes such as device holes in an insulating synthetic resin film such as phenol resin, polyester resin, epoxy resin, or tetrafluoroethylene resin, and then attaching the synthetic resin film to a copper foil. Then, by etching unnecessary parts of the attached copper foil to obtain a lead frame pattern using the copper foil, or by attaching the copper foil to the insulating resin film via an adhesive layer. After making necessary through-holes such as device holes in the foil-covered resin film, etching unnecessary parts of the copper foil to obtain a lead frame pattern using steel foil, or forming necessary through-holes such as the device holes. It is made by forming a metal lead frame pattern on a synthetic resin film with holes formed therein using the dragon bonding method.

However, in the conventional method described above, it takes time and effort to punch out necessary through holes such as device holes in the synthetic resin film using a punching die, and the synthetic resin film and steel foil are bonded together with an adhesive. It had to be done, and manufacturing it was not easy.

The present inventor has conducted research on a method for eliminating manufacturing complexity by omitting the process of punching out a synthetic resin film and the process of bonding between a synthetic resin film and copper foil in the production of conventional lead frames with supports. , we have completed the present invention. That is, the gist of the present invention is to form a lead frame by depositing metal on a region of a conductive pattern of a substrate having a conductive pattern shape using a haze deposition method, and to form a lead frame. A step of forming an electrically insulating support in which holes for silicon chips, device holes, etc. are opened on the above-mentioned substrate by an image forming method such as a printing method or a resist plate making method; This is a method for manufacturing a lead frame with a support, comprising the step of peeling off an integral body of the lead frame from the substrate.

According to the manufacturing method of the present invention, a lead frame with a support can be easily obtained without requiring a step of punching out the support and a step of bonding the support and the copper foil.

The present invention will be explained in detail below with reference to the drawings.

First, a negative lead frame pattern made of an electrically insulating material film (resist film) is formed on a conductive substrate such as a mirror-finished stainless steel plate using conventionally known methods such as photoresist plate making, screen printing, and offset printing. Form an image (resist image) or deposit S on a glass substrate or ceramic substrate by vacuum evaporation method.
Positive images of lead frame patterns made of metal thin films such as N02 and LN203 can be formed on glass substrates, ceramic substrates, steatite substrates, alumina substrates, or epoxy resins, phenolic resins, acrylic resins, fluorinated resins, polyethylene resins, and chlorinated resins. VL on plastic substrates such as vinyl resin, polyvinyl alcohol resin, etc.
-type, VH-type, VA-type (all manufactured by Tamura Seisakusho), Paste Silver 67, Paste Silver S-61 (
Made of metal thick film using conductive ink such as conductive paste #5900 (manufactured by Electroscience Laboratories Inc.), and conductive steel paste (manufactured by Mitsui Toatsu Chemical Co., Ltd.). A positive image of the lead frame pattern is formed to produce a substrate having a conductive pattern in the shape of the lead frame pattern. FIG. 1 shows a conductive/turn-containing substrate 5 produced by the former method.

A resist image 2 showing a negative image of the lead frame pattern is formed on the conductive substrate 1, and a conductive pattern 4 in the shape of the lead frame pattern is formed by the area of the conductive substrate turtle exposed from the closed part 3 of the resist image 2. is formed.

Moreover, FIG. 6 shows a substrate 14 having a conductive pattern produced by the latter method.

A conductive metal film image 13 showing a positive image of a dark frame pattern is formed on an electrically insulating substrate 12 by a plating method, a printing method, or the like. A release film (not shown) is formed on the substrate 5 having the conductive pattern shown in FIG. 1 or the substrate 4 having the conductive pattern shown in FIG. As shown in the figure, a metal 6 is deposited on the region of the conductive pattern 4 by the crab deposition method, and then the resist 2 is removed to form a lead frame made of a dew conductor as shown in the third figure, or as shown in the seventh figure. The lead frame 7 is formed by depositing the metal 6 on the conductive metal film image 13 by the tortoise deposition method.

Next, the substrate 5 or 1 on which the lead frame 7 is formed
4, an electrically insulating support 10 with closed silicon chip holes 8, device holes 9, etc. is formed as shown in FIG. 4 or 8 by an image forming method such as a printing method or a photoresist plate making method. do.

Here, the silicon chip placement hole 8 is a hole in which a silicon chip is placed. Next, the device hole 9 is a hole that crosses the inner lead, and after bonding one IC chip and the tip of the inner lead, the device hole 9 is made so that a part of the lead that crosses the device hole 9 remains. This is necessary for cutting and removing the peripheral portion of the lead frame with a support along the lines 1 and 2 to form a chip with leads having a lead portion protruding from the support 1.

Thereafter, the electrically insulating support 10 formed as described above
The integrated lead frame 7 is peeled off from the substrate 5 or 14 to obtain a lead frame 11 or li' with a support as shown in FIGS. 5a, b or 9.

When forming the support io by a printing method, it is desirable to employ a conventionally known screen printing method, gravure printing method, etc. as the printing method.

In addition, the inks used for printing include epoxy resins, acrylic resins, phenolic resins, pinyl chloride resins,
Fluorine resin, imide resin, amide resin, gelatin,
Inks containing casein or the like as a main ingredient, as well as inks having a composite composition obtained by adding organic and inorganic reinforcing substances to these inks, etc. can be used. Furthermore, after printing, it is necessary to perform ultraviolet curing or heat treatment to form a film.

On the other hand, when forming the support 10 using a photoresist plate making method, all commercially available photoresists can be used, but examples include KMER (manufactured by KODAK), G-90, and OMR (manufactured by KODAK). manufactured by Ohka) FSR, FR
-14FR-15 (manufactured by Fuji Pharmaceutical Co., Ltd.) alone and a composite composition obtained by adding an organic or inorganic reinforcing substance to these can be used.

FIG. 10 shows a chip with a lead formed using a lead frame with a support according to the manufacturing method of the present invention.

The chip 20 is placed in the silicon chip placement hole 8, and the tip of the inner lead of the chip 201 is bonded.
The peripheral portion of the lead frame with support is cut and removed along the device hole 9. As described above, according to the manufacturing method of the present invention, a lead frame with a support can be easily obtained without requiring the step of punching out the support and the step of bonding between the support and the copper foil.

Next, the present invention will be specifically explained with reference to Examples.

Example 1 1. A stainless steel plate with a mirror-polished surface to a thickness of 100 mm is prepared, and one surface of this plate is degreased with a 10% aqueous solution of Nitsusan Metalex (manufactured by Nippon Oil & Fats Co., Ltd.), and after washing with water,
A photosensitive liquid R-14 (manufactured by Fuji Pharmaceutical Co., Ltd.) is uniformly applied to a thickness of 4 to 7 mm and dried.

After that, after being force-dried for 6 to 1 minutes, a mask of the positive image of the lead frame was attached, exposed to ultraviolet-rich light, and washed and developed to form a negative photoresist image of the lead frame. , heat treatment at 150° C. to 10° C. for 10 to 18 minutes to solidify. The back side of a stainless steel plate having this negative photoresist image on one side was insulated with vinyl tape or varnish, and 3% anhydrous. 30-3 in muric acid aqueous solution
5. After soaking in sand and performing peeling treatment, rinse with water and apply sulfuric acid-based sulfuric acid steel plating solution (2S04, 2.5T) CuS042.
50 m/s), with copper as a cathode in the positive part 20 to 35 m
A positive conductive image of the desired lead frame is formed by exposing the lead frame to a thickness of about 100 mL. After plating, the stainless steel substrate is dried, and in order to form a support, electrically insulating ink is printed using a silk screen plate made in the shape of the support.
A film is formed by heating for 50 to 190q0l0 minutes. The thickness of the L support after heat treatment was on the 0.25 side. (Composition of electrically insulating ink) Thereafter, the electrically insulating ink-formed conductive pattern in the form of a support and lead frame is simultaneously physically peeled off from the stainless steel substrate to obtain an IJ board frame with a support. Ta.

Moreover, the stainless steel substrate can be used repeatedly from the plating process. Example 2 Prepare a lined glass sheet with a thickness of 2 ribs, and first prepare a conductive substrate by vapor depositing a conductive transparent film (transparency, 75% or more in the visible light range) with few pinholes mainly composed of 1 to 03 on one side. do.

Print a positive wiring pattern on this side using silk printing method (
Ink, E-60 to 70, manufactured by Taiyo Ink Manufacturing Co., Ltd.), and after heat treatment, the so-called negative area other than the ink adhesion was removed using FeC1.
After etching with an etching solution mainly containing 3 (3o~35o83, 5o~7oC), the printing ink is dissolved and removed with xylene or toluene, and a lead frame pattern made of a positive conductive transparent material is formed on the glass plate. obtain.

This glass substrate with conductive transparent wiring pattern was thoroughly degreased with a 10% aqueous solution of Nitsusan Metarex (manufactured by Nippon Oil & Fats Corporation) and washed with water.
2.5 evening/evening, copper is deposited as a cathode in CuS04250#' to a thickness of 20 to 35 mm on the positive part to form a positive conductive image of the desired lead frame.

After plating, the glass substrate was dried, and in order to form a support, a dew insulating ink was printed using a silk screen plate made in the shape of the support (including through-holes, etc.).
A film is formed by heating for 0 to 190q01 minutes. After the heat treatment, the thickness of the support was 0.25 mm. The composition of the electrically insulating ink for the support is as follows. Thereafter, the electrically insulating ink-formed conductive pattern in the form of a lead frame with a support was simultaneously physically peeled off from the glass substrate to obtain a lead frame with a support.

In addition, the glass substrate could be used repeatedly from the plating process.

Example 3 1. Prepare a stainless steel plate with a mirror-polished surface to Mononu thickness, degrease one side of this plate with a 10% aqueous solution of Nissan Metalex (manufactured by NOF), and after washing with water,
A photosensitive liquid R-14 (manufactured by Fuji Pharmaceutical Co., Ltd.) is uniformly applied to a thickness of 4 to 7 cm and dried.

After that, after 60q0l0 minutes of forced drying,
The lead frame was exposed to ultraviolet-rich light using a mask with a positive image on it, washed with water, and developed to form a negative photoresist image for the lead frame. The back side of the stainless steel plate, which has this negative photoresist image on one side, is insulated with vinyl tape or varnish, and a sulfuric acid steel plating solution (Hiyo○42
．． Copper is exposed as a cathode to a thickness of 20 to 35 mm on the positive part in a 59/1~CuS04250 Tazo wafer) to form a desired positive conductive image of the lead frame. After plating,
The stainless steel substrate is dried and a photosensitive material as described below is coated on the 015-0.17 thickness side. (Composition of photosensitive material) KMER (manufactured by KODAK) 100 polycalcium carbonate 30 tagarasu fiber powder
After 8 nights of natural drying, apply xylene for 20 minutes, force dry for 10 minutes, apply a positive image mask of the outer circumferential shape, through holes, lining holes, etc. By the development process, a support in which device pores etc. made of a photosensitive material are closed is obtained.

Thereafter, it was heat-treated at 120 to 140° C. for IS minutes to solidify it, and was peeled off from the stainless steel substrate together with the conductor pattern to obtain a lead frame with a support.

[Brief explanation of the drawing]

Figs. 5 to 5 show a method for manufacturing a lead frame with a support according to the present invention, Fig. 1 is a sectional view of a substrate having a conductive pattern in the shape of a lead frame pattern, and Fig. 2 is a cross-sectional view of a substrate having a conductive pattern in the shape of a lead frame pattern. A cross-sectional view showing a state in which metal is deposited on the
FIG. 3 is a sectional view showing a state in which the resist has been removed after metal deposition, FIG. 4 is a sectional view showing a state in which a support has been formed after that, and FIGS. 5a is a sectional view, and FIG. 5b is a plan view. FIGS. 6 to 9 show a second embodiment of the method for manufacturing a lead frame with a support according to the present invention; A cross-sectional view of a substrate having a pattern-shaped conductive pattern; FIG. 7 is a cross-sectional view showing a state in which metal is deposited on the substrate; FIG. 8 is a cross-sectional view showing a state in which a support is formed after metal deposition. Figure g is a cross-sectional view of the completed lead frame with a support, and Figure 0 is a cross-sectional view of the chip with leads. ...Regist image "3...Sekiguchi part"4...
...Conductive pattern, 5, vine 4...Substrate with conductive pattern, 6...Metal? …···Lead frame~
8...Silicon chip hole ~ 9...Device hole 10...Electrical insulating support, frame 1, Turtle'...Lead frame with support, 12... Electrically insulating substrate, 13...Desk conductive metal film image. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 5 Figure 10 Figure 6 Figure 7 Figure 8 Figure 9

Claims (1)

[Scope of Claims] 1. A step of forming a lead frame by depositing metal by electrodeposition on a region of the conductive pattern of a substrate having a conductive pattern in the shape of a lead frame pattern, and forming a lead frame. A step of forming an electrically insulating support in which holes for silicon chips, device holes, etc. are opened on the above-mentioned substrate by an image forming method such as a printing method or a resist plate making method; and peeling off the integrated lead frame from the substrate. 2. Claim 1 in which the substrate having the conductive pattern is formed by forming an electrically insulating resist image showing a negative image of the lead frame on the conductive substrate.
A method for manufacturing a lead frame with a support as described in . 3. The lead frame with a support according to claim 1, wherein the substrate having the conductive pattern is formed by forming a conductive metal thin film image showing a positive image of the lead frame pattern on an electrically insulating substrate. manufacturing method. 4. A patent claim in which an electrically insulating photosensitive liquid is applied onto the conductive substrate, and then an original plate of the lead frame pattern is placed on the photosensitive liquid coating, and after exposure, development is performed to form a negative image of the lead frame pattern. A method for manufacturing a lead frame with a support according to item 2. 5. The method of manufacturing a lead frame with a support according to claim 2, wherein a negative image of the lead frame pattern is formed on the conductive substrate by a printing method.