CN112331566B - Lead frame surface roughness manufacturing equipment and manufacturing method - Google Patents

Abstract

The invention discloses a manufacturing equipment and a manufacturing method of lead frame surface roughness, wherein the manufacturing equipment of the lead frame surface roughness comprises: the device comprises a discharging device, a cleaning device, an electrolytic copper device and a receiving device; the electrolytic copper device can regulate and control the surface roughness of the lead frame material through a pulse reverse electrolysis technology, and the electrolytic copper device comprises: the pulse reverse power supply can output pulse forward and reverse currents and forward and reverse pulse time; the number of the electrolytic copper process tanks is a plurality, the lead frame material can pass through the electrolytic copper process tanks, and the lead frame material continuously moves forwards to form a moving path; electrolytic copper lotion, in which the lead frame material can be immersed. The uniformity of the thickness of the electrolytic copper film of the lead frame material produced by the equipment is improved, the bonding strength of the surface of the lead frame material and the photosensitive dry film is enhanced, and the equipment has the advantages of high production efficiency, high product quality and the like.

Description

Lead frame surface roughness manufacturing equipment and manufacturing method

Technical Field

The invention belongs to the technical field of continuous lead frame surface treatment manufacturing, and in particular relates to a lead frame surface roughness manufacturing device and a manufacturing method.

Background Art

Precision integrated circuits made of high-precision chips and lead frames are important core electronic products in the modern electronic information industry. Among them, the important role of the lead frame is to support the chip, protect the internal components, and connect the external circuit. It is a key material in the integrated circuit. With the rapid development of electronic information high-tech, products are developing towards miniaturization, multi-function and intelligence. Therefore, the lead frame material is driven to develop in the direction of fine lead pitch and high density. This not only puts higher requirements on the strength and conductivity of the lead frame material, but also puts higher requirements on the processing performance of the material. For example, the lead frame material is not allowed to have defects such as scratches, peeling, oxidation, water marks and uneven appearance color.

The lead frame material manufacturing method for semiconductor integrated circuits has become the mainstream of using a photosensitive dry film hot pressing process on the lead frame material surface. In recent years, with the high integration of semiconductors, the requirements for the surface quality of lead frame materials have become increasingly higher due to the miniaturization of semiconductor packaging substrates and printed wiring substrate circuits. In other words, the surface roughness of the lead frame material is an important factor affecting the dry film hot pressing process, and it is also a key factor in whether the packaging process can be closely integrated with the packaging material. Therefore, the research and development of cleaning production equipment for the surface of lead frame materials has become a very important topic, especially the research and development of manufacturing methods and manufacturing equipment for the surface roughness of lead frame materials has become a topic that needs to be solved urgently.

Patent document 1 (CN 101864586 B): describes a method for preparing a lead frame material by pre-treating the metal material by degreasing and pickling and drying it, applying a photosensitive film to the upper and lower surfaces of the metal material by hot pressing, exposing the lead frame with the photosensitive film by ultraviolet light through a mold with a special lead frame pattern, and etching and electroplating the lead frame after treating it with a developing solution. However, this method has the defect that the photosensitive film is not firmly bonded to the surface of the metal material, resulting in the electroplating solution infiltrating the gap between the photosensitive film and the metal to be electroplated, and causing a small part of the etching area to not be etched or not be etched away at all.

Patent document 2 (JP 6406711 B2): describes a method for manufacturing a chip lead frame, wherein the first plating step includes sequentially forming a Ni plating layer, a Pd plating layer, and an Au plating layer at predetermined positions on the front and back of a metal plate. The second plating layer is preferably a method for forming an Ag plating layer. However, the manufacturing method is a chip production process, which has the disadvantages of low production efficiency and uneven product quality; in addition, the document does not record the cleaning process of the metal material.

Patent document 3 (JP 4431860 B2): describes a method for roughening the surface of copper and copper alloy materials using a surface roughening agent hydrogen peroxide and sulfuric acid system to provide a lead frame material. However, in recent years, due to the miniaturization of etching patterns, the requirements for the hot pressing bonding strength between the metal material surface and the photosensitive dry film have become increasingly higher, and the bonding strength of the metal surface provided by the surface roughening agent method is insufficient. In addition, the copper surface roughened by this method has the defect of being very easy to oxidize.

Patent document 4 (JP 1997-298265 A): A technique for forming multiple layers of nickel plating with different densities on the surface of a lead frame to improve the bonding strength with a packaging material is proposed. The lower layer of the multi-layer nickel plating is formed by a nickel plating layer that forms a smooth and dense layer, and the upper layer is formed by a pulse nickel plating layer that prioritizes crystal growth in the vertical direction. However, in this multi-layer plating technology, it is impossible to obtain sufficient surface roughness of the upper nickel plating layer, resulting in weak bonding with the packaging material. Therefore, this technology has the defect of insufficient bonding strength with the packaging material.

Patent document 5 (JP 2004-339584 A): Provides a technology for forming a plurality of different metal coatings on the surface of a lead frame to improve the bonding strength with the packaging material. Two nickel coatings of different thicknesses are successively plated under two different nickel plating conditions to make the total thickness of 1.0 μm, and then a 0.03 μm palladium coating is performed thereon, and a 0.01 μm gold coating is further performed on the palladium coating; although, in the process of forming the second layer of nickel, a pulse reverse electrolysis technology is used to obtain a lead frame with a suitable surface roughness, and the bonding strength with the packaging material can meet various product specification requirements. However, the gold electrolytically precipitated on the surface is a precious metal with extremely high chemical stability, and will not produce oxidation to roughen the surface, so it will reduce the bonding performance with the packaging material; at the same time, the production process requirements of the lead frame with multiple different metal coatings are high, and the precious metals used are expensive, which increases the product cost, and it is difficult to achieve in actual production.

Patent documents 1 to 5 provide a variety of lead frame production and processing methods. However, document 1 has the defect that the photosensitive dry film is not firmly bonded to the surface of the lead frame material, resulting in the electroplating solution penetrating the gap between the photosensitive film and the metal and being electroplated, resulting in a small part of the etching area not being etched or not being etched away at all; document 2 has the defects of low production efficiency and uneven product quality; in addition, the cleaning process of the metal material is not recorded in the text; document 3 uses a chemical solution to roughen the surface. The bonding strength of the metal surface provided is insufficient, and the roughened lead frame material surface has the defect of being very easy to oxidize. Document 4 has a multi-layer plating technology that cannot obtain sufficient surface roughness, resulting in weak bonding with the packaging material; therefore, this technology has the defect of insufficient bonding strength with the packaging material. Document 5 has a plurality of different precious metal plating lead frames with reduced bonding performance with the packaging material and high production process requirements. The precious metals used are expensive and the product cost increases, which is difficult to achieve in actual production and manufacturing.

The above-mentioned problems are major issues that need to be solved urgently in the lead frame surface treatment production line manufacturing industry. The bandwidth of the lead frame material is generally above 100mm, or even 300-400mm, while the bandwidth of the terminal material is generally below 20mm. It is more difficult to ensure uniform film thickness for surface treatment of lead frame materials with higher width. First of all, the following requirements must be met in the continuous production of the lead frame material surface treatment production line: 1) The lead frame material surface must be firmly bonded to the photosensitive dry film; 2) The surface roughness of the lead frame material must meet the requirements of firm hot-pressing bonding with the packaging material to ensure the quality and production efficiency of integrated circuit products; 3) The defect of uneven quality of lead frame products must be solved; 4) The surface roughness of the lead frame material must meet the requirements of firm hot-pressing bonding with the packaging material, and the thickness of the electrolytic copper film on the surface of the lead frame material must also be uniform; 5) The problem of insufficient hot-pressing bonding strength between the lead frame surface and the photosensitive dry film in the chemical solution roughening process and the defect that the material surface is very easy to oxidize must be solved. 6) Lead frame products with excellent corrosion resistance must be provided.

Summary of the invention

The present invention aims to solve at least one of the technical problems existing in the prior art.

To this end, the present invention proposes a wire frame surface roughness manufacturing device, the lead frame material produced by the wire frame surface roughness manufacturing device has improved uniformity of electrolytic copper film thickness, enhanced bonding strength between the lead frame material surface and the photosensitive dry film, not only has excellent corrosion resistance, excellent adhesion with packaging materials, but also product quality is guaranteed. The lead frame surface roughness manufacturing device has the advantages of high production efficiency, high product quality, high yield rate, etc.

To this end, the present invention also proposes a method for manufacturing the surface roughness of a wire frame, which has the advantages of high product quality and high production efficiency.

According to the manufacturing equipment of the lead frame surface roughness of the embodiment of the first aspect of the present invention, the following are arranged in order from front to back in the production process sequence: a feeding device, a cleaning device, an electrolytic copper device and a material receiving device, wherein the feeding device can feed the lead frame material on the material tray; the cleaning device can clean the lead frame material and remove surface impurities; the material receiving device can reel up the processed lead frame material; the electrolytic copper device can regulate the surface roughness of the lead frame material by pulse reverse electrolysis technology, and the electrolytic copper device comprises: a pulse reverse power supply, which can output pulse positive and reverse currents and positive and reverse pulse times; an electrolytic copper process tank, wherein the number of the electrolytic copper process tanks is multiple, the lead frame material can pass through the multiple electrolytic copper process tanks, and the lead frame material continuously moves forward to form a moving path; an electrolytic copper solution, wherein the electrolytic copper solution is arranged in the electrolytic copper process tank, and the lead frame material can be immersed in the electrolytic copper solution.

The manufacturing equipment for the surface roughness of the lead frame according to the embodiment of the present invention is mainly composed of a discharge device, a cleaning device, an electrolytic copper device and a receiving device. The cleaning device can obtain clean lead frame materials. In the electrolytic copper device, pulse reverse electrolysis technology is used to adjust and control the surface roughness of the lead frame material, which can not only increase the grain size and surface roughness of the Cu plating layer, so that a strong bonding effect is generated between the lead frame material and the packaging material, but also there are few defects such as pinholes in the electrolytic deposition layer, and it has good corrosion resistance. The uniformity of the electrolytic copper film thickness of the lead frame material produced by the equipment is improved, and the bonding strength between the surface of the lead frame material and the photosensitive dry film is enhanced. It not only has excellent corrosion resistance and excellent adhesion with the packaging material, but also the product quality is guaranteed. The manufacturing equipment for the surface roughness of the lead frame has the advantages of high production efficiency, high product quality, and high yield rate.

According to one embodiment of the present invention, two electrode plates are provided in each of the electrolytic copper process tanks. The two electrode plates are arranged opposite to each other on both sides of the lead frame material, and the moving path is located between the two electrode plates.

According to one embodiment of the present invention, the ratio of the surface area of the electrode plate to the surface area of the lead frame material immersed in each electrolytic copper process tank is 5:1.

According to one embodiment of the present invention, the shape of the electrode plate is formed into a flat surface, a mesh or a special shape, and the two electrode plates in each of the electrolytic copper process tanks are the same shape or a combination of different shapes.

According to the second aspect of the present invention, the lead frame surface roughness manufacturing equipment is used to adjust the lead frame surface roughness by pulse reverse electrolysis technology, and is characterized in that it includes the following steps:

S1. Analyze and test the surface roughness of the lead frame, and calculate the arithmetic average of the surface roughness of the lead frame;

S2, the lead frame material is led out from the unloading machine, enters the electrolytic degreasing tank for cleaning, and then enters the acid activation tank for cleaning to obtain a clean lead frame material;

S3, electrolytic copper plating section: according to the surface roughness of electrolytic copper, determine the pulse positive and reverse currents and the positive and reverse pulse times output by the pulse reverse power supply;

S4, applying the pulsed positive and reverse currents to the surface of the lead frame material through the electrode plate, and making the direction of the current applied to the lead frame material toward the electrode plate surface;

S5. Turn on the pulse reverse power supply, and after preheating, control the application of positive and reverse pulse currents and the positive and reverse pulse times according to the moving path of the lead frame material, and then pass through multiple electrolytic copper process tanks in sequence to obtain the lead frame surface roughness required for the product.

According to one embodiment of the present invention, the surface roughness of electrolytic copper = the surface roughness of the lead frame material required for the product - the surface roughness of the lead frame material.

According to one embodiment of the present invention, the arithmetic mean value of the surface roughness of the electrolytic copper is in the range of 0.05 μm to 5.0 μm.

According to one embodiment of the present invention, the pulse forward current range of the pulse reverse power supply output is 5A-500A, and the reverse current range of the pulse reverse power supply output is 20A-1000A.

According to one embodiment of the present invention, the pulse forward pulse time of the pulse reverse power supply output may be in the range of 5ms to 100ms; the pulse reverse pulse time of the pulse reverse power supply output may be in the range of 1ms to 30ms.

According to one embodiment of the present invention, an electrolytic copper solution is provided in the electrolytic copper process tank, and the electrolytic copper solution needs to meet the use range of the pulse forward and reverse current density output by the pulse reverse power supply.

According to one embodiment of the present invention, the pulse forward current density ranges from 2A/dm ² to 70A/dm ² , and the pulse reverse current density ranges from 5A/dm ² to 170A/dm ² .

Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

FIG. 1 is a flowchart of a method for manufacturing surface roughness of a lead frame according to an embodiment of the present invention.

FIG2 is an overall process flow chart of lead frame surface treatment;

FIG. 3 is a pulse reverse power output waveform diagram of a method for manufacturing surface roughness of a lead frame according to an embodiment of the present invention.

FIG. 4 is a diagram of a lead frame material surface roughness manufacturing device according to a lead frame surface roughness manufacturing method according to an embodiment of the present invention.

FIG. 5 is a diagram of a continuous lead frame material according to an embodiment of a method for manufacturing a lead frame surface roughness according to an embodiment of the present invention.

FIG. 6 is a diagram of a lead frame material surface roughness manufacturing device according to a lead frame surface roughness manufacturing method according to an embodiment of the present invention.

FIG. 7 is a diagram of a continuous lead frame material according to an embodiment of a method for manufacturing a lead frame surface roughness according to an embodiment of the present invention.

8 is a structural diagram of a manufacturing device for the surface roughness of a sheet lead frame material according to a method for manufacturing the surface roughness of a lead frame according to an embodiment of the present invention.

FIG. 9 is a structural diagram of a sheet lead frame material according to Embodiment 3 of a method for manufacturing surface roughness of a lead frame according to an embodiment of the present invention.

Reference numerals:

Pulse reverse power supply 300; Pulse reverse power supply 310-370;

Continuous lead frame material 200;

Continuous lead frame material 500;

Continuous lead frame material 700;

Discharging device 10; discharging guide wheel 11; cathode conductive 13a at the inlet; cathode conductive 13b at the outlet;

Electrolytic copper process tank 30; Electrolytic copper process tanks 30a-30g;

Electrode plate 40; upper anode plate 40a; lower anode plate 40b;

Material collecting guide wheel 50; material collecting device 51.

DETAILED DESCRIPTION

Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

The following describes in detail an apparatus for manufacturing the surface roughness of a lead frame according to an embodiment of the present invention with reference to the accompanying drawings.

As shown in FIG. 4 , the lead frame surface roughness manufacturing equipment according to the embodiment of the present invention includes: a material discharging device 10 , a cleaning device, a copper electrolysis device and a material receiving device 51 .

Specifically, according to the lead frame surface roughness manufacturing equipment of the embodiment of the present invention, the discharge device 10 can discharge the lead frame material on the material tray; the cleaning device can clean the lead frame material to remove surface impurities; the electrolytic copper device can adjust the surface roughness of the lead frame material through pulse reverse electrolysis technology, including: a pulse reverse power supply 300, the pulse reverse power supply 300 can output pulse positive and reverse currents and positive and reverse pulse times; electrolytic copper process tanks 30, the number of electrolytic copper process tanks 30 is multiple, the lead frame material can pass through multiple electrolytic copper process tanks 30, and the lead frame material continuously moves forward to form a moving path; electrolytic copper solution, the electrolytic copper solution is set in the electrolytic copper process tank 30, and the lead frame material can be immersed in the electrolytic copper solution. The material collection device 51 can roll up the processed lead frame material.

According to one embodiment of the present invention, two electrode plates 40 are provided in each electrolytic copper process tank 30, and the two electrode plates 40 are arranged on both sides of the lead frame material in a relative manner, and the moving path is located between the two electrode plates 40. The electrode plate 40 is an anode plate, and the number of the electrolytic copper process tanks 30 can be multiple. The electrolytic copper process tanks 30 are provided with a channel extending along the running direction of the lead frame material, and the lead frame material can pass through the electrolytic copper process tanks 30. Under the action of the pulse reverse power supply 300, electrolysis occurs in the electrolytic copper process tank 30, the lead frame material is the cathode, and the two electrode plates 40 are arranged on both sides of the lead frame material in a relative manner, so that electrolysis can occur on both sides of the lead frame material. According to the different directions of the current, copper can be precipitated or stripped from the surface of the lead frame material.

Furthermore, the surface area ratio of the electrode plate 40 to the surface area of the lead frame material immersed in each electrolytic copper process tank 30 is 5:1, preferably 3:1, and more preferably 2:1. In the electrolytic copper process tank 30, the electrode plate 40 is the anode plate, and the lead frame material is the cathode, that is, the requirement of the ratio of the anode material area to the cathode material area of 5:1 must be met.

Preferably, the shape of the electrode plate 40 is formed into a sheet, a mesh or a special shape, and the two electrode plates 40 in each electrolytic copper process tank 30 are the same shape or a combination of different shapes. The electrode plate 40 can be a combination of soluble metals and insoluble metals, or a non-soluble electrode plate 40 can be used to electrolyze precious metals on the surface of the electrode plate 40. The electrode plate 40 can be a flat plate bent into an arc shape, or a mesh bent into an arc shape, as long as the surface area ratio of the electrode plate 40 to the surface area of the lead frame material immersed in each electrolytic copper process tank 30 is 5:1. In other words, the shape of the two electrode plates 40 can be a combination of different shapes, one can be a sheet and the other can be a special shape, or one can be a mesh and the other can be a sheet. The size, shape and combination can be set according to actual needs, and it has high applicability. By adjusting the size and shape of the anode, the requirement of a ratio of the anode material area to the cathode material area of 5:1 can be met, so that the uniformity of the electrolytic copper film thickness on the surface of the lead frame material is improved, the product quality is guaranteed, and the production efficiency of the lead frame surface treatment production line is improved.

It should be noted that the lead frame material is transported horizontally through the electrolytic copper process tank. Because the bandwidth of the lead frame material is much larger than that of the terminal material, vertical transportation cannot ensure the stability of the lead frame material during operation, which in turn affects the surface roughness treatment. The horizontal transportation method is more stable and convenient for surface roughness treatment.

Therefore, the lead frame surface roughness manufacturing equipment according to the embodiment of the present invention is mainly composed of a discharge device 10, a cleaning device, an electrolytic copper device and a receiving device 51. The cleaning device can obtain clean lead frame materials, and the pulse reverse electrolysis technology is used in the electrolytic copper device to adjust and control the surface roughness of the lead frame material. The uniformity of the electrolytic copper film thickness of the lead frame material produced by the equipment is improved, and the bonding strength between the surface of the lead frame material and the photosensitive dry film is enhanced. It not only has excellent corrosion resistance and excellent adhesion with the packaging material, but also the product quality is guaranteed. The lead frame surface roughness manufacturing equipment has the advantages of high production efficiency, high product quality, and high yield rate.

It should be noted that the electrode plate 40 is also an anode plate, and the anode plate includes an upper anode plate 40a and a lower anode plate 40b.

The method for manufacturing the surface roughness of a lead frame according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in FIG. 1 and FIG. 2 , the method for manufacturing the surface roughness of a lead frame according to an embodiment of the present invention regulates the surface roughness of the lead frame by pulse reverse electrolysis technology, and includes the following steps:

S1. Analyze and test the surface roughness of the lead frame, and calculate the arithmetic average of the surface roughness of the lead frame;

S2, the lead frame material is led out from the unloading machine, enters the electrolytic degreasing tank for cleaning, and then enters the acid activation tank for cleaning to obtain a clean lead frame material;

S3, electrolytic copper plating section: according to the surface roughness of electrolytic copper, the pulse positive and reverse currents and the positive and reverse pulse times output by the pulse reverse power supply 300 are determined;

S4, applying pulsed positive and reverse currents to the surface of the lead frame material through the electrode plate 40, and making the direction of the current applied to the lead frame material toward the surface of the electrode plate 40;

S5. Turn on the pulse reverse power supply 300. After preheating, control the application of positive and reverse pulse currents and the positive and reverse pulse times according to the moving path of the lead frame material. After being processed in multiple electrolytic copper process tanks 30 in sequence, the lead frame surface roughness required for the product is obtained.

In other words, according to the manufacturing method of the lead frame surface roughness of the embodiment of the present invention, the surface roughness of the lead frame is regulated by the pulse reverse electrolysis technology, and the surface roughness of the electrolytic copper can be obtained by analyzing and testing the surface roughness of the lead frame, that is, the surface roughness Ra1 of the electrolytic copper = the surface roughness Ra2 of the lead frame material required for the product - the surface roughness Ra of the lead frame material. According to the surface roughness of the electrolytic copper, the optimal combination of the pulsed positive and reverse currents and the positive and reverse pulse times output by the pulse reverse power supply 300 can be determined.

First, the lead frame material is led out from the discharge 10 and passes through the discharge guide wheel 11, and then enters the electrolytic degreasing tank to clean and remove the grease on the surface of the metal material, and then enters the acid activation tank to clean and remove the rust and oxide on the surface of the metal material to obtain a clean lead frame material. Then it enters the electrolytic copper plating section. In the electrolytic copper process tank 30, the electrode plate 40 is the anode, and the lead frame material in the electrolytic copper solution is the cathode. Electrolysis occurs under the action of the pulse reverse power supply 300, and the roughness of the surface of the lead frame material changes. Specifically, the applied positive and reverse pulse currents and the positive and reverse pulse times are different, and the electrolysis occurring on the surface of the lead frame material is also different.

That is to say, in the pulse reverse electrolytic copper process, the current applied to the lead frame output by the pulse reverse power supply 300 changes periodically. When the pulse reverse power supply 300 applies a forward pulse current, copper is electrolytically precipitated on the surface of the lead frame, presenting a pulse forward waveform; when the pulse reverse power supply 300 applies a reverse pulse current, copper is electrolytically stripped from the surface of the lead frame material, presenting a pulse reverse waveform. After the repeated periodic changes of the pulse reverse power supply 300, copper is continuously precipitated and stripped from the surface of the lead frame material. By setting different forward and reverse pulse times, the amount of copper precipitated and stripped from the surface of the lead frame material can be controlled, thereby changing the thickness of the copper film. Specifically, when the forward pulse time is longer, more copper is precipitated on the surface of the lead frame material, and the copper film thickness is relatively thick. When the reverse pulse time is longer, more copper is stripped from the surface of the lead frame material, and the copper film thickness will become thinner. Not only can the thickness of the Cu plating layer be uniform, but also the surface roughness of the lead frame material can be different according to different requirements. By electrolytically stripping copper with a reverse pulse current, hydrogen atoms absorbed in the Cu plating layer on the surface of the lead frame can be removed, eliminating the brittleness of the Cu plating layer caused by hydrogen atoms contained in the copper layer and improving workability such as bending.

In addition, in the pulse reverse electrolytic copper process, Cu crystal particles with large grain size are easily formed. When the reverse pulse current is applied, the smaller the grain size, the more it is electrolytically stripped; this is because the smaller the grain size, the higher the surface free energy and the more unstable it is. As shown in Figure 3, when the forward pulse current and the reverse pulse current are applied alternately and repeatedly by using this periodically reversed polarity current waveform, a rough copper surface with large grains is formed. Therefore, a strong bonding effect is generated between the lead frame and the packaging material, so that a strong packaging material bonding performance can be obtained.

That is to say, when the pulse reverse power supply 300 electrolytic copper process is carried out, the precipitation of metal copper in the epitaxial growth of the crystal is faster than that in the generation of the crystal nucleus, which increases the grain size and surface roughness of the Cu plating layer. Due to this irregular shape and rough surface morphology, a strong bonding effect is generated between the lead frame material and the packaging material, so that the obtained packaging material has a strong bonding performance. When the current waveform of periodically reversed polarity alternately and repeatedly applies the forward pulse current and the reverse pulse current, the strain and impurity mixing caused by hydrogen absorption in the electrolytic copper layer are smaller than the strain and impurity mixing in the layer of the conventional direct current electrolytic copper. Therefore, there are few defects such as pinholes in the electrolytic deposition layer, and excellent corrosion resistance can be obtained. By replacing the chemical solution roughening process with the manufacturing method and manufacturing equipment of the lead frame material surface roughness of the present invention, the production efficiency of the lead frame surface treatment can be greatly improved and the product quality is greatly improved; by adjusting and controlling the surface roughness of the lead frame material, the scope of subsequent practical applications of the lead frame is expanded, and the product quality qualification rate is improved.

Therefore, according to the manufacturing method of the lead frame surface roughness of the embodiment of the present invention, the electrolytic copper process is implemented by pulse reverse electrolysis technology, which can not only increase the grain size and surface roughness of the Cu plating layer, so that a strong bonding effect is generated between the lead frame material and the packaging material, but also there are few defects such as pinholes in the electrolytic deposition layer, and it has good corrosion resistance. This method can replace the chemical solution roughening process, can greatly improve the production efficiency of the lead frame surface treatment, and the uniformity of the electrolytic copper film is improved, and the product quality is guaranteed. By adjusting and controlling the surface roughness of the lead frame material, the scope of the lead frame in subsequent practical applications is expanded, and the product quality qualification rate is improved.

According to one embodiment of the present invention, the surface roughness Ra1 of the electrolytic copper = the surface roughness Ra2 of the lead frame material required for the product - the surface roughness Ra of the lead frame material. The setting and adjustment of the pulsed positive and reverse currents and the positive and reverse pulse times output by the pulsed reverse power supply 300 are closely related to the distribution of the surface roughness of the electrolytic copper and the arithmetic mean of the surface roughness of the electrolytic copper. Therefore, the determination of the surface roughness of the electrolytic copper plays a great role in regulating the surface roughness of the lead frame by the pulsed reverse electrolysis technology.

Furthermore, the surface roughness of the electrolytic copper, the surface roughness of the lead frame material required for the product, and the arithmetic average of the surface roughness of the lead frame material are all in the range of 0.05 μm to 5.0 μm.

Optionally, the pulse forward current range of the pulse reverse power supply 300 is 5A to 500A, and the reverse current range of the pulse reverse power supply 300 is 20A to 1000A.

Furthermore, the pulse forward pulse time output by the pulse reverse power supply 300 can be selected in the range of 5ms to 100ms; the pulse reverse pulse time output by the pulse reverse power supply 300 can be selected in the range of 1ms to 30ms.

In some specific embodiments of the present invention, electrolytic copper solution is provided in the electrolytic copper process tank 30 , and the electrolytic copper solution needs to meet the use range of the pulse forward and reverse current density output by the pulse reverse power supply 300 .

Optionally, the pulse forward current density ranges from 2A/dm ² to 70A/dm ² , and the pulse reverse current density ranges from 5A/dm ² to 170A/dm ² . The pulse reverse power supply 300 outputs a current A=electrolytic copper solution current density A/dm ² ×material surface area dm ² ; the pulse forward current density preferably ranges from 5A/dm ² to 60A/dm ² , and more preferably ranges from 10A/dm ² to 50A/dm ² ; the pulse reverse current density preferably ranges from 10A/dm ² to 160A/dm ² , and more preferably ranges from 20A/dm ² to 150A/dm ² .

According to one embodiment of the present invention, two electrode plates 40 are provided in each electrolytic copper process tank 30, and the two electrode plates 40 are arranged on both sides of the lead frame material in a relative manner, and the moving path is located between the two electrode plates 40. The electrode plate 40 is an anode plate, and the number of the electrolytic copper process tanks 30 can be multiple. The electrolytic copper process tanks 30 are provided with a channel extending along the running direction of the lead frame material, and the lead frame material can pass through the electrolytic copper process tanks 30. Under the action of the pulse reverse power supply 300, electrolysis occurs in the electrolytic copper process tank 30, the lead frame material is the cathode, and the two electrode plates 40 are arranged on both sides of the lead frame material in a relative manner, so that electrolysis can occur on both sides of the lead frame material. According to the different directions of the current, copper can be precipitated or stripped from the surface of the lead frame material.

Furthermore, the surface area ratio of the electrode plate 40 to the surface area of the lead frame material immersed in each electrolytic copper process tank 30 is 5:1, preferably 3:1, and more preferably 2:1. In the electrolytic copper process tank 30, the electrode plate 40 is the anode plate, and the lead frame material is the cathode, that is, the requirement of the ratio of the anode material area to the cathode material area of 5:1 must be met.

Optionally, the shape of the electrode plate 40 is formed into a single surface, a mesh or a special shape. The electrode plate 40 can be a combination of a soluble metal and an insoluble metal, or a noble metal can be electrolyzed on the surface of the electrode plate 40 by using an insoluble electrode plate 40. The electrode plate 40 can be a flat plate bent into an arc shape, or a mesh bent into an arc shape, as long as the surface area ratio of the electrode plate 40 to the surface area of the lead frame material immersed in each electrolytic copper process tank 30 is 5:1.

Preferably, the two electrode plates 40 in each electrolytic copper process tank 30 are of the same shape or a combination of different shapes. That is to say, the shape of the two electrode plates 40 can be a combination of different shapes, one can be sheet-shaped and the other can be of a different shape, or one can be mesh-shaped and the other can be sheet-shaped, and the size, shape and combination can be set according to actual needs, which has high applicability. By adjusting the size and shape of the anode, the requirement of a ratio of the anode material area to the cathode material area of 5:1 can be met, so that the uniformity of the electrolytic copper film thickness on the surface of the lead frame material is improved, the product quality is guaranteed, and the production efficiency of the lead frame surface treatment production line is improved.

Therefore, the production by the manufacturing method of the lead frame surface roughness can meet the following requirements: 1) The lead frame material surface must be firmly bonded to the photosensitive dry film; 2) The lead frame material surface roughness must meet the requirements of firmly bonding with the packaging material by hot pressing to ensure the quality and production efficiency of integrated circuit products; 3) The defect of uneven quality of lead frame products must be solved; 4) The lead frame material surface roughness must meet the requirements of firmly bonding with the packaging material by hot pressing, and the thickness of the electrolytic copper film on the lead frame material surface must also be uniform; 5) The defect of insufficient hot pressing bonding strength between the lead frame surface and the photosensitive dry film in the chemical roughening process and the defect that the material surface is very easy to oxidize must be solved. 6) A lead frame product with excellent corrosion resistance must be provided.

In summary, the three elements of pulse reverse electrolysis technology based on pulse reverse power supply 300, selective metal anode, adjustment of anode size and shape, and copper solution for pulse electrolysis are the important foundation for providing high-quality and high-performance lead frame materials for the integrated circuit industry and continuously challenging high-end lead frame production and manufacturing technology. Not only can the uniformity of electrolytic copper film thickness on the surface of lead frame materials be improved, with excellent corrosion resistance and excellent adhesion to packaging materials, but also the product quality is guaranteed, and the production efficiency of the lead frame surface treatment production line is improved.

It should be noted that the lead frame material of the present invention can be a metal material, and the metal material can be any single body selected from copper, nickel, cobalt, tungsten, molybdenum, chromium and zinc, or an alloy composed of any two or more selected from copper, nickel, cobalt, phosphorus, tungsten, arsenic, molybdenum, chromium and zinc; it can also be iron and its iron alloys, and can also be various stainless steel materials; all metal materials can be continuous strips or continuous lead frame materials. In addition, all materials with metal foil on the surface can be processed by the manufacturing method and manufacturing equipment of the present invention for surface roughness production; for example, various plastic films with metal films on one or both sides can be used to manufacture the required surface roughness materials;

The optional width range of metal materials is 10mm~1000mm; the optional thickness range of metal materials is 0.03mm~0.30mm; the arithmetic mean value of the surface roughness of metal materials can be selected from 0.06μm~2.0μm

The following specific examples and comparative examples will enable those skilled in the art to more fully understand the present invention, but the present invention is not limited to the scope of the embodiments.

【Metal materials】

The lead frame material of the present invention can be a metal material, which can be any single material selected from copper, nickel, cobalt, tungsten, molybdenum, chromium and zinc, or an alloy composed of any two or more selected from copper, nickel, cobalt, phosphorus, tungsten, arsenic, molybdenum, chromium and zinc; it can also be iron and its iron alloy, or various stainless steel materials; all metal materials can be continuous strips or continuous lead frame materials. In addition, all materials with metal foil on the surface can be processed by the manufacturing method and manufacturing equipment of the present invention; for example, various plastic films with metal films on one or both sides can be used to manufacture the required surface roughness materials;

The optional width range of metal materials is 10mm～1000mm; the optional thickness range of metal materials is 0.03mm～0.30mm;

The arithmetic mean value of the surface roughness of the metal material can be selected in the range of 0.1μm to 10.0μm.

【Photosensitive dry film】

The surface of the photosensitive dry film and the surface of the metal material are heat-pressed to obtain a film-bonded metal material with strong adhesion and uniform surface quality. The thickness of the raw material of the photosensitive dry film can be selected in the range of 20 to 60 μm; the surface roughness of the raw material of the photosensitive dry film can be selected in the range of 0.75 to 1.87 μm; the thickness of the material after the metal material and the photosensitive dry film are laminated can be selected in the range of 0.05 to 0.36 mm; the roughness of one side of the photosensitive dry film can be selected in the range of 0.85 to 2.35 μm;

【Electrolytic copper solution】

The electrolytic copper solution used must be able to meet the following requirements: the forward current density can be in the range of 2A/dm ² to 70A/dm ² ; the reverse current density can be in the range of 5A/dm ² to 170A/dm ² ; the electrolytic copper solution must be able to electrolytically separate copper from the surface of the lead frame material under forward current conditions and to electrolytically strip copper from the surface of the lead frame material under reverse current conditions.

Example 1

(1) Analysis and measurement of surface roughness

As shown in Figure 5, the raw material copper strip C19400 has a width of 350 mm and a thickness of 0.12 mm. The roughness Ra is 0.08 to 0.15 μm when analyzed and tested by the shape measuring instrument VK-X series. The average value calculated from multiple sets of data is 0.11 μm.

(2) According to the requirements of hot pressing of the selected photosensitive dry film, the surface roughness range of the metal material Ra is 1.3 to 1.5 μm.

(3) The surface roughness of the material manufactured by pulse reverse electrolysis technology is Ra = (1.2~1.5μm)-(0.08~0.15μm), that is, the production and processing roughness range Ra is 1.12~1.35μm.

(4) According to the product production and processing requirements, the metal material is subjected to double-sided roughness surface treatment.

(5) Manufacturing of surface roughness of lead frame materials

As shown in Figure 1, first, the metal raw material is discharged from the discharge 10 and passes through the discharge guide wheel 11, and then enters the electrolytic degreasing tank to clean and remove grease on the surface of the metal material, and then enters the acid activation tank to clean and remove rust and oxides on the surface of the metal material to obtain a clean metal material.

Then, in the first electrolytic copper process tank 30a, upper and lower anode plates 40a and lower anode plates 40b are provided on the upper and lower sides of the lead frame material and connected to the anode output of the pulse reverse power supply 310; the cathode conductive 13a at the inlet and the cathode conductive 13b at the outlet are connected to the cathode output of the pulse reverse power supply 310. The connection method from the second electrolytic copper area to the seventh copper plating area is the same as the connection method of the first electrolytic copper area, as shown in Figures 1 and 4.

As shown in Table 1, since the raw material copper strip width is 350 mm, the surface area is large, and the surface roughness Ra 1.30-1.50 μm of the lead frame material required by the product is quite different from the raw material roughness Ra 0.08-0.15 μm, it is preferred to use a 7-unit electrolytic copper process for surface roughness treatment; the total amount of surface roughness of the lead frame manufactured by seven pulse reverse power supplies 310 to 370 is set to 21 equal parts, and the surface roughness of each part is 0.06-0.07 μm; for example, the pulse reverse power supply 310 of experimental condition No. 1 accounts for 15 parts, and the surface roughness range Ra 0.92-1.07 μm is required after treatment, and the 6 pulse reverse power supplies 300 of pulse reverse power supplies 320 to 370 each account for 1 part, and after treatment with each pulse reverse power supply 300, the surface roughness of the material must meet Ra 0.06-0.07 μm.

The running speed of the lead frame material surface roughness manufacturing production line is preferably 1.5 m/min. When the 7 pulse reverse power supplies 300 adopt condition No. 7 in Table 1, the roughness of the 7 electrolytic copper layers is in the range of 0.18 to 0.21 μm, that is, the forward and reverse pulse currents and forward and reverse pulse time conditions set by the 7 pulse reverse power supplies 300 are the same, and the surface roughness and density obtained from the bottom layer to the surface layer are very small, and the surface characteristics of the lead frame material are uniform.

When condition No. 1 is adopted, the pulse reverse power supply 310 needs to set a larger forward pulse current and a longer forward pulse time, while the setting value of the reverse pulse current should be smaller and the reverse pulse time should be shorter; the electrolytic copper obtained has a larger roughness and a poorer density; the setting conditions of the subsequent six pulse reverse power supplies 320 to 370 are smaller forward pulse currents and longer forward pulse times compared with condition No. 7, while the setting value of the reverse pulse current is slightly larger than that of condition No. 7, and the reverse pulse time is much shorter than that of No. 7; therefore, the surface roughness obtained meets the product specifications and has a better surface density than condition No. 7.

When conditions No. 2 to No. 6 are adopted, the surface roughness of the lead frame material meets the requirements and the density range is between conditions No. 1 and No. 7.

When condition No.13 is adopted, the six pulse reverse power supplies 310 to 360 need to set a smaller forward pulse current and a longer forward pulse time, and set a large reverse pulse current and a very short reverse pulse time; the resulting copper plating layer has a smaller roughness and better density. The setting conditions of the last pulse reverse power supply 370 are a larger forward pulse current and a longer forward pulse time, and a larger reverse pulse current and a shorter reverse pulse time, so the surface roughness obtained meets the product specifications, but the surface density is poorer than that of condition No.7.

When conditions No. 8 to No. 12 are adopted, the surface roughness of the lead frame material meets the requirements and the density is between conditions No. 7 and No. 13.

The surface roughness of the lead frame is analyzed and tested using the VK-X series shape measurement tester. The lead frame raw copper material is used as the raw material for subsequent silver plating, and must be able to form a dense and solid bonding layer with the silver plating layer, which is the standard for judging the surface specifications of the lead frame.

Use photosensitive dry film to verify the effect of surface roughness and density on lead frame materials.

After selecting the brand and model of the photosensitive dry film, the roughness Ra of the VK-X series of shape measuring and testing instruments is 1.3-1.85μm, and the average value Ra of multiple sets of data is 1.58μm; the surface roughness specification range of the metal material manufactured above after hot pressing by the laminator is 1.57-1.93μm. Using this specification range as the inspection standard, the metal materials manufactured under the above conditions and the products pressed by the photosensitive dry film are tested by the shape measuring and testing instrument VK-X, which can determine the best manufacturing method for the surface roughness of the metal material and the best setting conditions of the pulse reverse power supply 300.

Therefore, the best condition in this embodiment is No.2.

Example 2

(1) Analysis and measurement of surface roughness

As shown in Figure 7, the rolled lead frame has a width of 115 mm and a thickness of 0.15 mm, and the metal raw material is C14410. The roughness Ra is 0.12 to 0.21 μm when analyzed and tested by the shape measuring instrument VK-X series, and the average value calculated by multiple sets of data is 0.17 μm.

(2) According to the requirements of the subsequent silver plating process, the lead frame surface roughness requirement range is 2.5 to 3.7 μm;

(3) The surface roughness Ra manufactured by pulse reverse electrolysis technology is (2.5-3.7 μm)-(0.12-0.21 μm), that is, the production and processing roughness range Ra is 2.38-3.49 μm.

(4) According to the production and processing requirements, the single side of the lead frame material is subjected to roughness surface treatment.

(5) Lead frame surface treatment

As shown in Figure 1, first, the metal raw material is discharged from the discharge 10 and passes through the discharge guide wheel 11, and then enters the electrolytic degreasing tank to clean and remove grease on the surface of the metal material, and then enters the acid activation tank to clean and remove rust and oxides on the surface of the metal material to obtain a clean metal material.

Then, in the first electrolytic copper process tank 30a, upper and lower anode plates 40a and lower anode plates 40b are provided on the upper and lower sides of the lead frame material and connected to the anode output of the pulse reverse power supply 310; the cathode conductive 13a at the inlet and the cathode conductive 13b at the outlet are connected to the cathode output of the pulse reverse power supply 310. The connection method from the second electrolytic copper area to the sixth electrolytic copper area is the same as the connection method of the first electrolytic copper area, as shown in FIG6 .

As shown in Table 2, the width of the rolled lead frame material is 115 mm, and the surface area is less than one-third of that in Example 1. A 6-unit electrolytic copper process is used for surface roughness treatment. The surface roughness of the material required by the product is Ra2.38-3.49 μm. The total amount of the surface roughness of the manufactured metal of the six pulse reverse power supplies 310 to 360 is set to 18 equal parts, and the surface roughness of each equal part is 0.132-0.193 μm. For example, the pulse reverse power supply 310 of the experimental condition No. 1 accounts for 11 parts, and the surface roughness range Ra 1.454-2.132 μm is required after treatment. The pulse reverse power supply 320 accounts for 3 parts, and the surface roughness range Ra 0.396-0.581 μm is required after treatment. The four pulse reverse power supplies 300 of the pulse reverse power supplies 320 to 360 each account for 1 part. After treatment with each pulse reverse power supply 300, the surface roughness of the material must meet Ra 0.132～0.193μm.

The running speed of the lead frame material surface roughness manufacturing production line is preferably 2.0 m/min; when the six pulse reverse power supplies 300 adopt condition No. 9 in Table 2, the roughness range of the six electrolytic copper layers is 0.396-0.581 μm, that is, the forward and reverse pulse currents and forward and reverse pulse time conditions set by the six pulse reverse power supplies 300 are the same, and the surface roughness and density obtained from the bottom layer to the surface layer are very small, and the surface characteristics of the lead frame material are uniform.

When condition No. 1 is adopted, the pulse reverse power supply 310 needs to be set with a larger forward pulse current and a longer forward pulse time, while the setting value of the reverse pulse current should be smaller and the reverse pulse time should be shorter; the electrolytic copper obtained has a larger roughness and a poorer density; the conditions required to be set for the pulse reverse power supply 320 are the same as the conditions adopted by the six pulse reverse power supplies 300 in No. 9, and the setting conditions of the subsequent four pulse reverse power supplies 330 to 360 are smaller forward pulse currents and longer forward pulse times compared with condition No. 9, while the setting value of the reverse pulse current is slightly larger than that of condition No. 9, and the reverse pulse time is much shorter than that of No. 9; therefore, the surface roughness of the electrolytic copper obtained meets the product specification requirements, and the surface density is better than that of condition No. 9.

When conditions No. 2, No. 3, No. 4, No. 5, No. 6, No. 7 and No. 8 are adopted, the surface roughness of the lead frame material meets the requirements and the density is between No. 1 and No. 9.

When condition No.17 is adopted, the four pulse reverse power supplies 310 to 340 need to set a smaller forward pulse current and a longer forward pulse time, and set a large reverse pulse current and a very short reverse pulse time; the resulting copper plating layer has a smaller roughness and better density. The conditions required to be set for the pulse reverse power supply 350 are the same as the conditions used by the six pulse reverse power supplies 300 in No.9. The setting conditions for the last pulse reverse power supply 360 are a larger forward pulse current and a longer forward pulse time, and a larger reverse pulse current and a shorter reverse pulse time are set. Therefore, the surface roughness obtained meets the product specifications, but the surface density is poorer than that of condition No.9.

When conditions No. 8 to No. 16 are adopted, the surface roughness of the lead frame material meets the requirements and the density is between conditions No. 9 and No. 17.

Therefore, the best condition in this embodiment is No.3.

Example 3

(1) Analysis and measurement of surface roughness

As shown in Figure 9, the chip lead frame has a width of 105mm and a thickness of 0.20mm, and the metal raw material is C14410. The roughness Ra of the shape measuring instrument VK-X series is 0.15 to 0.23μm, and the average value Ra of multiple sets of data is 0.19μm.

(2) According to the requirements of the subsequent silver plating process, the lead frame surface roughness requirement range is Ra 3.5 to 4.9 μm.

(3) The surface roughness Ra manufactured by pulse reverse electrolysis technology is (3.5-4.9 μm)-(0.15-0.23 μm), that is, the production and processing roughness range Ra is 3.35-4.67 μm;

(4) According to the production and processing requirements, the single side of the chip lead frame is subjected to roughness surface treatment;

(5) Surface treatment of chip lead frame

As shown in FIG1 , first, the lead frame material is discharged from the discharge 10 and passes through the discharge guide wheel 11, and then enters the electrolytic degreasing tank to clean and remove grease on the surface of the metal material, and then enters the acid activation tank to clean and remove rust and oxides on the surface of the metal material to obtain a clean metal material.

Then, in the first electrolytic copper process tank 30a, upper and lower anode plates 40a and lower anode plates 40b are provided on the upper and lower sides of the lead frame material and connected to the anode output of the pulse reverse power supply 310; the cathode conductive 13a at the inlet and the cathode conductive 13b at the outlet are connected to the cathode output of the pulse reverse power supply 310. The connection method from the second electrolytic copper area to the sixth electrolytic copper area is the same as the connection method of the first electrolytic copper area, as shown in Figures 3 and 8.

As shown in Table 3, the chip lead frame has a width of 105 mm and a surface area less than one-third of that in Example 1. The surface roughness of the electrolytic copper process of 5 units is preferably processed; the surface roughness of the material required by the product is Ra3.35-4.67 μm; the total amount of the surface roughness of the metal manufactured by the five pulse reverse power supplies 310 to 350 is set to 20 equal parts, and the surface roughness of each equal part is 0.167-0.233 μm; for example, the pulse reverse power supply 310 of the experimental condition No. 1 accounts for 15 parts, and the surface roughness range Ra 2.512-3.503 μm is required after treatment, the pulse reverse power supply 320 accounts for 2 parts, and the surface roughness range Ra 0.335-0.467 μm is required after treatment, and the three pulse reverse power supplies 300 of the pulse reverse power supplies 320 to 350 each account for 1 part, and after treatment with each pulse reverse power supply 300, the surface roughness of the material must meet Ra 0.167～0.233μm.

The operating speed of the surface roughness manufacturing production line of the chip lead frame material is preferably 1.5m/min; when the five pulse reverse power supplies 300 adopt condition No. 9 in Table 3, the roughness range of the five electrolytic copper layers is all between 0.670 and 0.934μm, that is, the forward and reverse pulse currents and forward and reverse pulse time conditions set by the six pulse reverse power supplies 300 are the same, and the surface roughness and density obtained from the bottom layer to the surface layer are very small, and the surface characteristics of the lead frame material are uniform.

When condition No. 1 is adopted, the pulse reverse power supply 310 needs to set a larger forward pulse current and a longer forward pulse time, while the setting value of the reverse pulse current should be smaller and the setting value of the reverse pulse time should be shorter; the electrolytic copper obtained has a larger roughness and a poorer density; the conditions required to be set for the pulse reverse power supply 320 are different from the conditions adopted by the five pulse reverse power supplies 300 of No. 9, which adopt a smaller forward pulse current and a longer forward pulse time, while the setting value of the reverse pulse current is slightly larger than that of condition No. 9, and the reverse pulse time is much shorter than that of No. 9; the setting conditions of the subsequent three pulse reverse power supplies 330 to 350 are smaller forward pulse currents and longer forward pulse times compared with condition No. 9, while the setting value of the reverse pulse current is slightly larger than that of condition No. 9, and the reverse pulse time is much shorter than that of No. 9. Therefore, the surface roughness of the electrolytic copper obtained meets the product specification requirements, and the surface density is better than that of condition No. 9.

When conditions No. 2, No. 3, No. 4, No. 5, No. 6, No. 7 and No. 8 are adopted, the surface roughness of the lead frame material meets the requirements and the density is between No. 1 and No. 9.

When condition No. 17 is adopted, the three pulse reverse power supplies 310 to 330 need to be set with a smaller forward pulse current and a longer forward pulse time, and a larger reverse pulse current and a very short reverse pulse time; the copper plating layer obtained

The roughness is small and the density is good. The conditions required to set the pulse reverse power supply 340 are different from the conditions used by the five pulse reverse power supplies 300 in No. 9. A smaller forward pulse current and a longer forward pulse time are used, and the setting value of the reverse pulse current is slightly larger than that of condition No. 9, and the reverse pulse time is much shorter than that of No. 9; the setting conditions of the last pulse reverse power supply 350 are a larger forward pulse current and a longer forward pulse time, and a larger reverse pulse current and a shorter reverse pulse time are set. Therefore, the surface roughness obtained meets the product specifications, but the surface density is worse than that of condition No. 9.

When conditions No. 8 to No. 16 are adopted, the surface roughness of the lead frame material meets the requirements and the density is between conditions No. 9 and No. 17.

Therefore, the best condition in this embodiment is No.4.

Table 1, Table 2, and Table 3 are respectively the allocation quotas of the lead frame surface roughness corresponding to 7 pulse reverse power supplies 300, the allocation quotas of the lead frame surface roughness corresponding to 6 pulse reverse power supplies 300, and the allocation quotas of the lead frame surface roughness corresponding to 5 pulse reverse power supplies 300. They include the number of allocations and the specific surface roughness range of each pulse reverse power supply 300.

Table 1: Distribution of lead frame surface roughness for 7 pulse reverse power supplies Unit: μm

Table 2: Distribution of lead frame surface roughness for 6 pulse reverse power supplies Unit: μm

Table 3: Distribution of lead frame surface roughness for 5 pulse reverse power supplies Unit: μm

Therefore, the output current of each unit of the optional pulse reverse power supply 300 is adjusted to be different, and the output pulse time of each unit of the optional pulse reverse power supply 300 is also adjusted to be different. By selecting various permutations and combinations of different setting condition units, a test plan with a required range of surface roughness is designed and the experimental results are optimized, and the best experimental method for material surface roughness is selected to obtain the required lead frame material surface roughness required for lead frame production.

The electrolytic copper process for adjusting and controlling the surface roughness of the lead frame material can be selected in the range of 3 units to 12 units, preferably in the range of 4 units to 11 units, and more preferably in the range of 5 units to 10 units.

As shown in Figures 1 to 9, according to the manufacturing method of the surface roughness of the lead frame material according to the embodiment of the present invention, the lead frame material can be electrolytically processed into the surface roughness required by the product. The continuous lead frame materials 200, 500 and 700 are surface treated by pulse reverse electrolysis technology and preferred electrolytic copper solution. The production and processing conditions of the surface roughness of the lead frame material can be determined by designing a test plan with a required range of surface roughness, and optimizing the experimental results to select the best manufacturing method of the material surface roughness, which has high continuous production and processing efficiency, increases the bonding strength between the surface of the lead frame material and the photosensitive dry film and the bonding strength with the packaging material, and improves the quality of the lead frame product.

The lead frame material of the present invention can be a metal material, and the metal material can be any single body selected from copper, nickel, cobalt, tungsten, molybdenum, chromium and zinc, or an alloy composed of any two or more selected from copper, nickel, cobalt, phosphorus, tungsten, arsenic, molybdenum, chromium and zinc; it can also be iron and its iron alloy, and can also be various stainless steel materials; all metal materials can be continuous strips or continuous lead frame materials. In addition, all materials with metal foil attached to the surface can be processed by the manufacturing method and manufacturing equipment of the present invention for surface roughness production. For example, various plastic films with metal films attached to one or both sides can be used to manufacture the required surface roughness materials.

The thickness of the lead frame material can be in the range of 0.03mm to 0.80mm, preferably in the range of 0.05mm to 0.55mm, and more preferably in the range of 0.07mm to 0.35mm; the width of the metal material can be in the range of 50mm to 1000mm, preferably in the range of 80mm to 700mm, and more preferably in the range of 100mm to 500mm.

The surface of the photosensitive dry film and the surface of the lead frame material must be subjected to heat pressing treatment to obtain a film lead frame material with a strong bond and uniform surface thickness. The thickness of the photosensitive dry film raw material can be in the range of 20 to 100 μm, preferably in the range of 20 to 80 μm, and more preferably in the range of 20 to 80 μm. In addition, the surface roughness of the photosensitive dry film raw material can be in the range of 0.65 to 2.17 μm, preferably in the range of 0.55 to 2.07 μm, and more preferably in the range of 0.50 to 1.97 μm. The roughness of one side of the photosensitive dry film after the photosensitive dry film is heat-pressed with the lead frame material can be in the range of 1.05 to 2.65 μm, preferably in the range of 0.95 to 2.50 μm, and more preferably in the range of 0.85 to 2.30 μm.

The pulse reverse electrolysis technology is composed of the current of the forward pulse waveform and the reverse pulse waveform output by the pulse reverse power supply 300 being transmitted to the surface of the lead frame material through the anode plate and the electrolytic copper solution, as well as the forward pulse time and the reverse pulse time. Preferably, the double pulse forward current output by the pulse reverse power supply 300 can be selected in the range of 5A to 500A, preferably in the range of 10A to 450A, and more preferably in the range of 20A to 430A; the reverse current output by the double pulse rectifier can be selected in the range of 20A to 1000A, preferably in the range of 30A to 900A, and more preferably in the range of 50A to 850A; the double pulse forward pulse time output by the pulse reverse power supply 300 can be selected in the range of 5ms to 100ms, preferably in the range of 7ms to 70ms, and more preferably in the range of 10ms to 50ms; the reverse pulse time output by the pulse reverse power supply 300 can be selected in the range of 1ms to 30ms, preferably in the range of 3ms to 20ms, and more preferably in the range of 5ms to 10ms.

The forward current density of the electrolytic copper solution may be in the range of 2A/dm ² to 70A/dm ² , preferably in the range of 5A/dm ² to 60A/dm ² , and more preferably in the range of 10A/dm ² to 50A/dm ² ; the reverse current density of the electrolytic copper solution may be in the range of 5A/dm ² to 170A/dm ² , preferably in the range of 10A/dm ² to 160A/dm ² , and more preferably in the range of 20A/dm ² to 150A/dm ² .

Furthermore, the ratio of the surface area of the anode plate to the surface area of the lead frame material immersed in each electrolytic copper solution tank can be selected as 5:1, preferably 3:1, and more preferably 2:1; the anode plate can be made of soluble metals and insoluble metals, or the method of electrolyzing precious metals on the surface of insoluble anode plates can be adopted; the shape of the anode can be sheet-shaped and mesh-shaped, or it can be a special shape, such as bending a flat plate into an arc shape, or bending a mesh into an arc shape, and for example, various combinations of different sizes and distributions of holes punched on a flat plate according to different positions. In order to meet the requirement of a ratio of anode area to cathode area of 5:1, two or more anodes of different shapes can also be combined. The optional range of the arithmetic mean of the surface roughness of the lead frame is 0.05μm to 5.0μm, preferably 0.07μm to 4.5μm, and more preferably 0.09μm to 3.9μm.

Other structures and operations of the lead frame surface roughness manufacturing equipment according to the embodiment of the present invention are understandable and easy to implement for those skilled in the art, and thus will not be described in detail.

In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims (8)

1. A lead frame surface roughness manufacturing device, characterized in that, in accordance with the production process sequence, it is provided with: a feeding device, a cleaning device, an electrolytic copper device and a material receiving device in sequence from front to back, wherein the feeding device can feed the lead frame material on the material tray; the cleaning device can clean the lead frame material to remove surface impurities; the material receiving device can reel up the processed lead frame material; the electrolytic copper device can regulate the surface roughness of the lead frame material by pulse reverse electrolysis technology, and the electrolytic copper device comprises: A pulse reverse power supply, which can output pulse positive and reverse currents and positive and reverse pulse times; Electrolytic copper process tanks, the number of which is multiple, the lead frame material can pass through the multiple electrolytic copper process tanks, and the lead frame material continuously moves forward to form a moving path; Electrolytic copper solution, the electrolytic copper solution is arranged in the electrolytic copper process tank, and the lead frame material can be immersed in the electrolytic copper solution; Two electrode plates are arranged in each of the electrolytic copper process tanks, the two electrode plates are arranged oppositely on two sides of the lead frame material, and the moving path is located between the two electrode plates; The ratio of the surface area of the electrode plate to the surface area of the lead frame material immersed in each electrolytic copper process tank is 5:1; The shape of the electrode plate is formed into a flat surface, a mesh or a special shape, and the two electrode plates in each electrolytic copper process tank are the same shape or a combination of different shapes; The lead frame material is conveyed horizontally through the electrolytic copper process tank. 2. A method for manufacturing the surface roughness of a lead frame, using the lead frame surface roughness manufacturing equipment according to claim 1, and regulating the surface roughness of the lead frame by pulse reverse electrolysis technology, characterized in that it comprises the following steps: S1. Analyze and test the surface roughness of the lead frame, and calculate the arithmetic average of the surface roughness of the lead frame; S2, the lead frame material is led out from the unloading machine, enters the electrolytic degreasing tank for cleaning, and then enters the acid activation tank for cleaning to obtain a clean lead frame material; S3, electrolytic copper plating section: according to the surface roughness of electrolytic copper, determine the pulse positive and reverse currents and the positive and reverse pulse times output by the pulse reverse power supply; S4, applying the pulsed positive and reverse currents to the surface of the lead frame material through the electrode plate, and making the direction of the current applied to the lead frame material toward the electrode plate surface; S5. Turn on the pulse reverse power supply, and after preheating, control the application of positive and reverse pulse currents and the positive and reverse pulse times according to the moving path of the lead frame material, and then pass through multiple electrolytic copper process tanks in sequence to obtain the lead frame surface roughness required for the product. 3. The method for manufacturing the surface roughness of a lead frame according to claim 2, characterized in that the surface roughness of the electrolytic copper = the surface roughness of the lead frame material required for the product - the surface roughness of the lead frame material. 4. The method for manufacturing the surface roughness of a lead frame according to claim 3, characterized in that the arithmetic mean value of the surface roughness of the electrolytic copper is in the range of 0.05 μm to 5.0 μm. 5. The method for manufacturing the surface roughness of a lead frame according to claim 2, characterized in that the pulse forward current output by the pulse reverse power supply ranges from 5A to 500A, and the reverse current output by the pulse reverse power supply ranges from 20A to 1000A. 6. The method for manufacturing the surface roughness of a lead frame according to claim 2 is characterized in that the pulse forward pulse time of the pulse reverse power supply output is in the range of 5ms to 100ms; the pulse reverse pulse time of the pulse reverse power supply output is in the range of 1ms to 30ms. 7. The method for manufacturing the surface roughness of a lead frame according to claim 2 is characterized in that an electrolytic copper solution is provided in the electrolytic copper process tank, and the electrolytic copper solution needs to meet the use range of the pulse forward and reverse current density output by the pulse reverse power supply. 8. The method for manufacturing the surface roughness of a lead frame according to claim 7, characterized in that the pulse forward current density ranges from 2A/dm2 to 70A/dm2, and the pulse reverse current density ranges from 5A/dm2 to 170A/dm2.