TWI699458B - Lead frame material and manufacturing method thereof - Google Patents

Abstract

Provided is a lead frame material suitable for manufacturing a lead frame capable of improving resin adhesion in a high temperature and high humidity environment that has been sought in recent years, and a manufacturing method thereof.

A lead frame material and a manufacturing method thereof. The lead frame material has a roughened layer on a conductive substrate (1), the roughened layer is composed of a plurality of roughened layers, and the roughened layer has a vertical direction of the conductive substrate A vertical roughening layer (2) composed of at least one layer, and further having at least one additional roughening layer (3) above the vertical roughening layer, and each of the vertical roughening layer and the additional roughening layer Among the unevennesses, the interval between the vertices of the adjacent convex portions of the vertical roughening layer is different from the interval between the vertices of the adjacent convex portions of the additional roughening layer.

Description

Lead frame material and manufacturing method thereof

The present invention relates to a lead frame material for electrically connecting a semiconductor element and a lead frame subjected to a plating process to each other and sealing the resin-sealed semiconductor device with a mold resin, and a manufacturing method thereof.

This type of resin-sealed semiconductor device is formed by sealing a semiconductor element and a lead frame electrically connected to each other by a metal wire or the like with a mold resin. In this type of resin-sealed semiconductor device, the mainstream is that the lead frame is subjected to exterior plating such as Sn-Pb, Sn-Bi.

Among them, in recent years, in order to simplify the assembly steps and reduce costs, lead frames (Pre Plated Frame, hereinafter referred to as PPF) that have been plated (such as Ni/Pd/Au) on the surface of the lead frame in advance have begun to be used. When mounting on a printed circuit board with solder or the like, plating is a specification that improves the wettability with solder (for example, refer to Patent Document 1).

On the other hand, a technique has been proposed to roughen the plating surface of the lead frame in order to improve the adhesion between the lead frame and the mold resin in the resin-sealed semiconductor device (for example, refer to Patent Document 2, Patent Literature 3).

These techniques for roughening the plating surface are by roughening the plating surface of the lead frame, and it is expected that (1) the bonding area between the lead frame and the mold resin becomes larger, and (2) the mold resin is easy to Enter the roughening effect of the coating (anchor effect), etc.

According to the above, the adhesion of the lead frame to the mold resin is improved, which can prevent The peeling between the lead frame and the mold resin is prevented, and the reliability of the resin-sealed semiconductor device is improved.

[Patent Document 1] Japanese Patent Application Publication No. 4-115558

[Patent Document 2] Japanese Patent Application Laid-Open No. 6-29439

[Patent Document 3] Japanese Patent Application Laid-Open No. 10-27873

Rough plating based on these shapes can indeed improve resin adhesion better than before. However, it can be known that under the high reliability level required in recent years, for example, after 168 hours in an environment with a temperature of 85°C and a humidity of 85%, gaps between the resin and the lead frame can be seen everywhere. It is believed that the reason is: QFN (Quad Flat Non-Leaded Package) type or SOP (Small Outline Package) type packages, which are not commonly used since the past, have become widely used, and the requirements for adhesion are higher. In this way, it can be seen that there is still room for improvement.

The subject of the present invention is to provide a lead frame material suitable for manufacturing a lead frame capable of improving resin adhesion in a high temperature and high humidity environment that has been sought in recent years, and a manufacturing method thereof.

The inventors of the present invention made efforts to research and develop the aforementioned problems. As a result, they focused on the shape of the roughened layer formed on the conductive substrate, and studied the shape that can maximize the anchoring effect of the lead frame material and the resin. As a result, it was found that not only a vertical roughening layer (at least one roughening layer is formed in the vertical direction of the substrate), but also at least one additional roughening layer (shape after roughening) on the upper layer. Among the concavities and convexities of the vertical roughening layer and the additional roughening layer, the space between the apexes of the adjacent convex portions (concave and convex peaks) of the vertical roughening layer The gap is different from the apex of the adjacent convex portion (concave-convex peak) of the additional roughening layer, thereby significantly improving the resin adhesion compared with the previous one, and can ensure the resin adhesion in the high temperature and high humidity test. The present invention was completed based on this knowledge.

That is, the present invention provides the following means:

(1) A lead frame material having a roughened layer on a conductive substrate, wherein the roughened layer is composed of a plurality of roughened layers, and the roughened layer has at least one layer in the vertical direction of the conductive substrate. Constitute a vertical roughened layer, and further have at least one or more additional roughened layers on the upper layer of the vertical roughened layer, and in the concavities and convexities of the vertical roughened layer and the additional roughened layer, the vertical roughened The interval between the apexes of adjacent convex portions of the layer is different from the interval between the apexes of adjacent convex portions of the additional roughening layer.

(2) The lead frame material as in (1), wherein the line segment length of the outermost layer section (the line segment length of the outermost layer section, the line segment length of the outermost layer section of the lead frame material including the additional roughening layer) (A) The value of the ratio (A/B) to the line segment length of the conductive substrate cross section (the conductive substrate cross section line segment length) (B) is 1.2 or more and 4 or less.

(3) The lead frame material according to (1) or (2), characterized in that: the conductive substrate is copper or copper alloy, iron or iron alloy, aluminum or aluminum alloy.

(4) The lead frame material according to any one of (1) to (3), characterized in that the plurality of roughened layers are composed of two layers, and have a first vertical roughened in the vertical direction of the conductive substrate. The roughened layer and the second additional roughened layer above the vertical roughened layer, and the vertical roughened layer and the additional roughened layer have different compositions.

(5) The lead frame material according to (4), wherein the interval between the apexes of the convex portions of the additional roughening layer is narrower than the interval between the apexes of the convex portions of the first vertical roughening layer.

(6) The lead frame material according to any one of (1) to (5), characterized in that the composition of the vertical roughening layer is made of copper or copper alloy.

(7) The lead frame material according to any one of (1) to (6), wherein the composition of the additional roughening layer is composed of any one of nickel, nickel alloy, cobalt, and cobalt alloy.

(8) The lead frame material according to any one of (1) to (7), wherein the conductive substrate has a vertical roughening layer that is roughened in a vertical direction, and has an additional roughening layer as the vertical The upper layer of the roughened layer, and the layer above the additional roughened layer, has a single layer or multiple layers on the entire surface or part of the lead frame material made of palladium, palladium alloy, rhodium, rhodium alloy, ruthenium, ruthenium alloy, platinum, platinum A surface layer composed of any one of alloy, iridium, iridium alloy, gold, gold alloy, silver, and silver alloy.

(9) A method of manufacturing a lead frame material, which is the method of manufacturing a lead frame material according to any one of (1) to (8), characterized in that: any one of the above-mentioned vertical roughening layer and additional roughening layer Either or both are formed by electroplating.

(10) A semiconductor package using the lead frame material of any one of (1) to (8) above.

The inventors of the present invention have found that in a lead frame material having a roughened layer formed on a conductive substrate, the formed roughened layer is composed of a plurality of roughened layers, and the roughened layer has a surface formed on the conductive substrate. A vertical roughening layer composed of at least one or more layers in the vertical direction, and further the upper layer of the vertical roughening layer also has at least one or more additional roughening layers that are roughened, in the vertical roughening layer and the additional roughening In the unevenness of each layer, the interval between the apexes of the adjacent protrusions of the vertical roughening layer is different from the interval between the apexes of the adjacent protrusions of the additional roughening layer, whereby the resin not only penetrates into the vertical direction of the substrate, but also Penetrate into the horizontal direction, not only by being as thick as before The chemical treatment increases the surface area, and through the wedging effect based on the additional roughening layer, the mechanical bonding strength with the resin is significantly increased. As a result, the high-temperature and high-humidity adhesion of the resin that could not be tolerated before is obtained. For example, even in a high-temperature and high-humidity environment of 168 hours at 85°C and 85%, the lead frame material and the resin can be greatly suppressed The generation of gaps provides excellent resin adhesion.

1‧‧‧Conductive substrate

2‧‧‧Vertical roughening layer

3‧‧‧Additional roughening layer

4‧‧‧Surface

4'‧‧‧First surface

5‧‧‧Second surface

6‧‧‧Interval between vertical roughening layers

7‧‧‧Additional roughening layer interval

8‧‧‧Substrate section length

9‧‧‧Extreme surface section length

9a‧‧‧Total length of the section length of the outermost layer

11‧‧‧Conductive substrate (copper, copper alloy, iron, iron alloy, etc.)

12‧‧‧Copper base plating layer

13‧‧‧Nickel roughening coating

14‧‧‧Surface layer (grows along the nickel roughening coating)

Figure 1 is a schematic cross-sectional view of one aspect of the present invention.

Figure 2 is a schematic cross-sectional view of another aspect of the present invention.

Fig. 3 is a schematic cross-sectional view of another aspect of the present invention.

Fig. 4 is an enlarged view of a schematic cross-sectional view of an aspect of the present invention.

Fig. 5 is an enlarged view of a schematic cross-sectional view of the above-mentioned form shown in Fig. 4 of the present invention.

Figure 6 is a schematic cross-sectional view of the previous form. In FIG. 6, 11 represents a conductive substrate, 12 represents a copper base plating layer, 13 represents a nickel roughened plating layer, and 14 represents a surface layer.

(Vertical roughening layer)

According to the present invention, first, there is a roughened layer in a direction perpendicular to the conductive substrate (hereinafter referred to as the substrate), that is, a vertical roughened layer. The roughened layer of the lead frame material is composed of a plurality of vertical roughened layers, and preferably has one vertical roughened layer. The vertical roughened layer refers to a roughened layer formed in a direction perpendicular to the main surface of the substrate, and means that is formed approximately in the direction perpendicular to the main surface of the substrate. Preferably, when viewed from a vertical cross section with respect to the longitudinal direction of the substrate, the growth direction of the convex portion of the roughened layer (the apex of the peak) is formed within 20° from the perpendicular to the main surface of the substrate. The vertical The roughened layer is a roughened layer that serves as a basis for imparting adhesiveness to the resin, and is preferably composed of copper, copper alloy, nickel, nickel alloy, cobalt, cobalt alloy, or the like, for example. In particular, from the viewpoint of improving the adhesion between the substrate and the upper film (additional roughening layer etc. below), the vertical roughening layer made of copper or copper alloy is more preferable. Examples of copper alloys, nickel alloys, and cobalt alloys include copper-tin alloys as copper alloys, nickel-zinc alloys as nickel alloys, and cobalt-tin alloys as cobalt alloys.

(The thickness of the vertical roughening layer)

Furthermore, the thickness of the vertical roughening layer is not particularly limited, but there is a tendency that the larger the film thickness, the larger the unevenness due to roughening. Therefore, in order to increase the roughened shape, the coating thickness of the vertical roughened layer is preferably 0.2 μm or more, more preferably 0.5 μm or more, and still more preferably 0.8 μm or more. On the other hand, if the thickness of the coating exceeds 3 μm, there is a concern that the roughened layer may fall off during transportation, and the so-called "dust falling" may increase. Therefore, the coating thickness of the vertical roughening layer is preferably 3 μm or less, more preferably 2 μm or less, and still more preferably 1.5 μm or less. In addition, considering the complexity of the manufacturing steps, etc., the number of vertical roughening layers is preferably within 2 layers. In addition, these coating thicknesses represent non-local judgments and can be obtained by measuring at least three arbitrary points with a collimator diameter of 0.2 mm or more by the fluorescent X-ray method (for example, a film thickness measuring device such as SFT9400 (trade name) manufactured by SII) The average film thickness.

(Additional roughening layer)

Furthermore, according to the present invention, the layer above the vertical roughening layer has an additional roughening layer composed of one or more layers, preferably one additional roughening layer. With the presence of the additional roughening layer, it is possible to impart resin adhesion to a level that cannot be achieved only by the previous roughening of the unevenness (for example, refer to FIG. 6). The additional roughening layer is a layer above the vertical roughening layer, and is preferably a part that is roughened in such a way that the peak-to-peak interval is narrower (smaller) than the vertical roughening layer. The additional roughening layer is formed to impart a wedging effect to the resin. The additional roughening layer is preferably formed as much as possible to deviate from the 90° perpendicular to the substrate ±20° The part formed by the above angle. That is, it is preferable that the additional roughening layer is more inclined with respect to the 90° perpendicular to the base. As a result, not only the anchoring effect of the first layer is increased, but the expansion and contraction of the resin caused by the high temperature environment or high humidity environment can also be followed not only in two dimensions but also in three dimensions. Therefore, the resin adhesion is improved compared with the past. The additional roughening layer is preferably made of a material with good adhesion to the vertical roughening layer, and examples thereof include copper, copper alloy, nickel, nickel alloy, cobalt, cobalt alloy, silver, and silver alloy. Among them, it is preferably any one of nickel, nickel alloy, cobalt, and cobalt alloy in terms of imparting a function as a barrier layer to prevent diffusion of the matrix component. Furthermore, the additional roughening layer is preferably composed of a different composition from the vertical roughening layer. Examples of copper alloys, nickel alloys, cobalt alloys, and silver alloys include copper-tin alloys as copper alloys, nickel-zinc alloys as nickel alloys, cobalt-tin alloys as cobalt alloys, and silver-tin alloys as silver alloys.

(Film thickness of additional roughening layer)

The thickness of the additional roughening layer is not particularly limited, but there is a tendency that the larger the film thickness, the larger the unevenness due to roughening. On the other hand, if it is too thick, the irregularities of the vertical roughened layer may be buried. Therefore, it is 1/10 or more of the coating thickness of the vertical roughening layer, preferably 1/5 or more. On the other hand, the upper limit of the coating thickness of the additional roughening layer is preferably at most the same thickness as the coating thickness of the vertical roughening layer, and more preferably 2/3 or less of the vertical roughening layer thickness.

(Shape (thickness) of the vertical roughening layer and the additional roughening layer)

In addition, since the shape of the roughened layer obtained in the present invention utilizes the wedging effect based on the additional roughened layer, its degree cannot be expressed by measurement of the roughness of the surface. Therefore, it is possible to measure the line segment length (total length of the line segment length of the cross section of the outermost layer) of the cross section of the outermost layer after all the film layers (the above-mentioned roughened layers) are formed during the cross-sectional observation, and compare it to the cross-section of the conductive substrate The value of the ratio of the length of the line segment is used as a length indicator. The length of the line section of the conductive substrate (B) When set to 1, the value of the ratio (A/B) of the line segment length of the outermost surface section (the line segment length of the outermost surface section) (A) is preferably 1.2 times or more, more preferably 2 times or more. As a result, the specific surface area increases, and the adhesion to the resin increases. On the other hand, when the line segment length (B) of the conductive substrate cross-section is set to 1, if the value of the ratio (A/B) of the line segment length (A) of the outermost cross-section exceeds about 4 times, the powder will fall off easily. Therefore, it is preferably 4 times or less, and more preferably 3.5 times or less.

In the present invention, the vertical roughening layer and the additional roughening layer can be used to improve the resin adhesion to the sealing material.

(Shape of each roughening layer)

Furthermore, in the present invention, the vertical roughened layer and the additional roughened layer are formed, so the respective concavities and convexities cannot be grasped only by the measurement of the outermost layer, but by observing from the cross section, the adjacent roughened layers can be observed The distance between the apexes of the convex part (concave and convex of each roughened layer). Regarding this matter, for example, after processing any roughened layer section by Focused Ion Beam: FIB, it can be confirmed by Scanning Ion Mycroscope: SIM image based on the contrast of the crystal grain size. The adjacent convex portions of each roughened layer The interval of the vertices can be judged according to the scale. In each roughening layer, the average interval between the vertices of the adjacent convex portions of the vertical roughening layer and the additional roughening layer is called "the interval between the vertical roughening layer (the interval between the convex portions)" and the "additional roughening layer". In the case of "interval between the raised layers", the interval between the vertical roughening layer and the interval between the additional roughening layer are different. Preferably, the interval between the vertical roughening layer is larger than the interval between the additional roughening layer. Thereby, since the resin easily enters between the vertical roughened layers, the resin adhesion can be further improved. As the ratio of the interval, the interval of the additional roughening layer is preferably 1/2 or less of the interval of the vertical roughening layer, more preferably 1/4 or less. On the other hand, if it exceeds 1/20, the additional roughening layer becomes too fine and the adhesive force continues to decrease, so it is preferably 1/20 or more, and more preferably 1/15 or more. Furthermore, when there are multiple vertical roughening layers, it will be the vertical roughness of the maximum interval. The roughened layer is the target, and when the additional roughened layer has a plurality of layers, the additional roughened layer formed on the outermost surface is the target. In addition, as the interval ratio of each roughened layer, it is obtained by calculating the average value of the interval between the protrusions and the protrusions at any five adjacent positions in the cross-sectional observation.

In the vertical roughening layer, by changing the current density or the coating thickness, the crystal grain size of the roughening layer can be changed to control the convex-convex spacing of the additional roughening layer. By performing roughening plating on the roughening layers of different compositions, the variation of the interval ratio of the protrusions can be controlled. Specifically, the thickness and average interval of each roughening layer can be set separately as follows: the higher the current density, the narrower the interval, and the lower the current density, the wider the interval.

(Conductive substrate)

In addition, the metal matrix (conductive matrix) component used is preferably copper or copper alloy, iron or iron alloy, aluminum or aluminum alloy, etc. Among them, copper or copper alloy having good electrical conductivity is preferable.

For example, as an example of a copper alloy, "C14410 (Cu-0.15Sn, manufactured by Furukawa Electric Co., Ltd., trade name: EFTEC (registered trademark)-3)", "C19400", which is an alloy disclosed by CDA (Copper Development Association), can be used. (Cu-Fe-based alloy material, Cu-2.3Fe-0.03P-0.15Zn)", "C18045 (Cu-0.3Cr-0.25Sn-0.5Zn, manufactured by Furukawa Electric Co., Ltd., trade name: EFTEC-64T) "Wait. Furthermore, the unit of the number before each element is mass%. Since the electrical conductivity or strength of the copper alloy substrates are different, they are selected and used according to the appropriate required characteristics, but it is preferable to set the copper alloy strips with electrical conductivity above 50% IACS.

Moreover, as iron or iron alloy, 42 alloy (Fe-42mass%Ni), stainless steel, etc. are used, for example. The conductivity of these ferroalloy substrates is not so high, but it can be applied to lead frames that do not have such high requirements for conductivity and are used for the transmission of electrical signals.

In addition, as aluminum or aluminum alloy, for example, A5052 or the like is used.

The thickness of the substrate is not particularly limited, and is usually 0.05 mm to 2 mm, preferably 0.1 mm to 1 mm.

(Roughened plating upper layer and surface layer)

In addition, according to the present invention, in order to impart the solder wettability, wire bonding, die bonding, and other characteristics of the lead frame to the upper layer (surface layer) of the additional roughening layer, The entire surface or part of the lead frame material is formed into a single layer or multiple layers made of palladium, palladium alloy, rhodium, rhodium alloy, ruthenium, ruthenium alloy, platinum, platinum alloy, iridium, iridium alloy, gold, gold alloy, silver, silver alloy A film composed of any one of them. Among them, as a representative layer structure, Pd/Au coating, Pd/Ag/Au coating, Pd/Rh/Au coating, Ru/Pd/Au coating, etc., in order from the roughened layer side to the surface can be cited. The thickness of the coating is not particularly limited, but if it is too thick, there is a possibility that the roughened layer may be buried in unevenness and cannot function, or the cost may increase due to precious metals. In this article, "predominantly precious metals" means that more than 50% by mass of the constituent components are precious metals. In terms of these, the total coating thickness is preferably 1 μm or less. Palladium alloys, rhodium alloys, ruthenium alloys, platinum alloys, iridium alloys, gold alloys, and silver alloys include palladium-silver alloys as palladium alloys, rhodium-palladium alloys as rhodium alloys, ruthenium-iridium alloys as ruthenium alloys, and platinum- Gold alloy is used as platinum alloy, iridium-ruthenium alloy is used as iridium alloy, gold-silver alloy is used as gold alloy, silver-tin alloy is used as silver alloy and so on.

(Coated part of roughened layer)

In addition, the formation site of the roughened layer in the present invention only needs to be formed with at least a part of the resin molded part. For example, it is preferable to form at least 1/5 or more of the part of the lead frame molded by resin, and it is more preferable to form it to an area of 1/2 or more, thereby exhibiting the effect of improving adhesion. It is best to implement it on the entire surface of the resin mold. As the shape of the partially arranged roughening layer, it is possible to adopt Various forms such as strips, dots, and rings. Furthermore, in a product in which resin molding is performed on only one side, for example, the roughened layer can be formed on only one side.

In addition, according to the present invention, the roughening plating can be controlled relatively easily by current density or stirring and is simple. Therefore, when either or both of the vertical roughening layer and the additional roughening layer are formed, it is preferable to use Formed by electroplating. Further, from the viewpoint of productivity, it is more preferable to form both by wet plating.

Hereinafter, the present invention will be explained in detail based on the drawings.

Figure 1 is a schematic cross-sectional view of one aspect of the present invention. A vertical roughening layer 2 is formed on the upper layer of the conductive substrate 1, and an additional roughening layer 3 is formed on the upper layer. The upper part of the additional roughening layer 3 is covered with a resin mold (not shown). As in this aspect, in a product (semiconductor package) in which resin molding is performed on only one side, for example, the roughened layer can be formed on only one side, and of course it can also be formed on both sides.

Figure 2 is a schematic cross-sectional view of another aspect of the present invention. A vertical roughening layer 2 is formed on the upper layer of the conductive substrate 1, and an additional roughening layer 3 is formed on the upper layer, and further, in order to impart solder wettability or wire bonding properties of the lead frame to the surface layer, and grain bonding The whole surface is formed in a single layer with palladium, palladium alloy, rhodium, rhodium alloy, ruthenium, ruthenium alloy, platinum, platinum alloy, iridium, iridium alloy, gold, gold alloy, silver, silver alloy Film layer (surface layer) 4 composed of any one of them. The upper part of the film layer 4 is covered with a resin mold (not shown). The coating layer 4 is a layer formed to impart characteristics such as solder wettability, wire bonding, and die bonding properties of the lead frame, and may be partially formed, for example, on a portion molded by resin. The shape can also be formed into strips, dots, rings, etc.

Fig. 3 is a schematic cross-sectional view of another aspect of the present invention. For conductivity A vertical roughening layer 2 is formed on the upper layer of the flexible substrate 1, and an additional roughening layer 3 is formed on the upper layer, and further, in order to impart solder wettability, wire bonding, and crystal grain adhesion to the surface layer of the lead frame. Features, formed in two layers, made of any one of palladium, palladium alloy, rhodium, rhodium alloy, ruthenium, ruthenium alloy, platinum, platinum alloy, iridium, iridium alloy, gold, gold alloy, silver, and silver alloy The film layer 4'(first surface layer) and the film layer 5 (second surface layer). The upper part of the film layer 5 is covered with a resin mold (not shown). At this time, the coating layers 4'and 5 are formed of different metal types. For example, the coating layer 4'is preferably Pd, Rh, Ru, Ir, etc., and the coating layer 5 is preferably Au, Ag, Pt, etc. In FIG. 3, the coating layers 4'and 5 are formed on the entire surface. However, in order to reduce the amount of precious metals used, the coating layers 4'and 5 can also be formed only on parts that require wire bonding or welding, etc., thereby saving precious metals It adopts an environment-friendly and low-cost form.

Fig. 4 is an enlarged view of a schematic cross-sectional view of one aspect of the present invention. A vertical roughening layer 2 is formed on the conductive substrate 1 and an additional roughening layer 3 is formed on the upper layer, and this Fig. 4 shows the A schematic diagram of the interval 6 between the vertical roughening layer and the interval 7 between the additional roughening layer. In this way, the intervals between the vertical roughening layer 2 and the additional roughening layer 3 (6 and 7 respectively) are different. Furthermore, it is preferable that the interval 7 between the additional roughening layer is smaller (narrow) than the interval 6 between the vertical roughening layer. The reason is that the resin being molded enters the gap of the relatively large vertical roughened layer 2, and the additional roughened layer 3 formed by the present invention takes the wedging effect on the resin, thereby more powerfully and Resin adhesion, as a result, the resin adhesion can be maintained even in tests with severe esters such as high temperature and humidity.

5 is an enlarged view of the schematic cross-sectional view of the above-mentioned form shown in FIG. 4 of the present invention. A vertical roughening layer 2 is formed on the conductive substrate 1 and an additional roughening layer 3 is formed on the upper layer, and FIG. 5 is a schematic diagram showing the cross-sectional line length 8 (B) of the conductive substrate and the cross-sectional line length 9 (A) of the outermost layer. Here, the so-called section line length of the most surface layer is 9 series Refers to the total length of the zigzag as shown in the figure (the length 9a after the zigzag is stretched as shown in Figure 5). In the present invention, in the value obtained by dividing the total length of the section line segment length of the outermost layer 9a(A) by the section length of the conductive substrate 8(B), the value of the ratio (A/B) (length of the section line section of the outermost layer) The ratio of the total length 9a (A) divided by the cross-sectional length of the conductive substrate 8 (B)) is preferably 1.2 or more, more preferably 2 or more, whereby the specific surface area increases and the adhesion to the resin increases. On the other hand, if the value of the ratio of line segment length (A/B) exceeds about 4, it may be easy to fall off. Therefore, the value of the ratio of line segment length (A/B) is preferably 4 or less, more preferably It is 3.5 times or less.

[Example]

Hereinafter, the present invention will be described in further detail based on examples, but the present invention is not limited to these.

The various conductive substrates shown in Table 1 with a test piece size of 40mm×40mm and a thickness of 0.2mm are prepared in advance. After pretreatment of the cathodic electrolytic degreasing and pickling steps shown below, they are formed in the invention example Vertical roughening layer and additional roughening layer. As a comparative example, after forming the vertical roughened layer, a normal Ni layer was formed as an additional roughened layer. Furthermore, as the previous example, it is prepared to form only a roughened Ni layer as a roughened layer. In addition, as the upper layer of each sample, after forming a 0.02 μm Pd plating on the upper layer of the additional roughening layer, a 0.01 μm Au plating was further formed on the upper layer as the outermost layer. Invention Examples 1 to 15 are the forms shown in FIG. 3. Comparative Example 1 is a form in which the Cu base plating layer 12 is not provided in the form shown in FIG. 6. The previous example 1 is the form shown in FIG. 6. The thickness and average interval of each roughening layer can be set separately as follows: the higher the current density, the narrower the interval, and the lower the current density, the wider the interval.

In the vertical roughening layer, the crystallization of the vertical roughening layer is achieved by changing the current density or coating thickness The particle size changes to control the convex-convex spacing of the additional roughened layer. By performing roughening plating on the layers of different compositions, the interval between the protrusions is changed, thereby controlling the interval (ratio). The roughening thickness can be set according to the processing time, and the average interval can be set according to the current density. In addition, measure the length of the outermost section line segment (the total length of the outermost section line segment) (A) and the conductive substrate section line segment length (B), and find the ratio (the total length of the outermost section line section length 9a (A) divided by the conductive The length of the cross section of the sex matrix is 8 (B) value) (A/B) value. Show it in the table as "Surface Section Line Segment Length Ratio".

(Pretreatment conditions)

[Cathode Electrolytic Degreasing]

Degreasing liquid: NaOH 60g/liter

Degreasing conditions: 2.5A/dm ² , temperature 60℃, degreasing time 60 seconds

[Pickling]

Pickling liquid: 10% sulfuric acid

Pickling conditions: 30 seconds, immersion, room temperature

(Roughening plating conditions)

[Roughened Cu plating (forms vertical roughening layer)]

Plating solution: copper sulfate: copper concentration is 5~10g/liter, sulfuric acid: 30~120g/liter, ammonium molybdate: Mo metal is 0.1~5.0g/liter

Plating conditions: bath temperature 20~60℃, current density 10~60A/dm ²

[Roughening Ni plating (form additional roughening layer)]

Plating solution: WDB-321 (trade name) manufactured by World Metal Co., Ltd.

Plating conditions: current density 8A/dm ² , temperature 70℃

(General intermediate plating conditions)

[Ni Plating] (Normal Ni Plating)

Plating solution: Ni(SO ₃ NH ₂ ) ₂ . 4H ₂ O 500g/liter, NiCl ₂ 30g/liter, H ₃ BO ₃ 30g/liter

Plating conditions: current density 10A/dm ² , temperature 50℃

[Co Plating (form additional roughening layer)]

Plating solution: Co(SO ₃ NH ₂ ) ₂ ‧4H ₂ O 500g/liter, CoCl ₂ 30g/liter, H ₃ BO ₃ 30g/liter

Plating conditions: current density 10A/dm ² , temperature 50℃

(Pd plating conditions)

[Pd plating (form the first surface layer)]

Plating solution: Pd(NH ₃ ) ₂ Cl ₂ 45g/liter, NH ₄ OH 90 ml/liter, (NH ₄ ) ₂ SO ₄ 50g

/L, Para Sigma gloss agent (trade name, manufactured by Matsuda Industrial Co., Ltd.) 10ml/L

Plating conditions: current density 5A/dm ² , temperature 60℃

(Au plating conditions)

[Au plating (form second surface layer)]

Plating solution: KAu(CN) ₂ 14.6g/liter, C ₆ H ₈ O ₇ 150g/liter, K ₂ C ₆ H ₄ O ₇ 180g/liter

Plating conditions: temperature 40℃

For the test pieces of the invention example, the comparative example, and the previous example produced separately, the resin mold was formed into a contact area of 4mm ^{2 by a} transfer mold test device (product name: Model FTS) manufactured by Uitaki Seiki Co., Ltd. The pudding-like test piece. This test piece was put into a high temperature and high humidity test (85° C., 85% RH, 168 hours), and the test piece was subjected to resin adhesion evaluation and the like. The results are shown in Table 1.

(Evaluation of resin adhesion)

Evaluation resin: G630L, manufactured by Sumitomo Bakelite Co., Ltd. (trade name)

Evaluation conditions:

Device: 4000Plus, manufactured by Nordson‧Advanced‧Technology (trade name),

Load yuan: 50kg

Measuring range: 10kg

Testing speed: 100μm/s

Test height: 10μm

"A" (excellent) means an average of 10kgf/mm ² or more, "B" (good) means an average of 5kgf/mm ² or more and less than 10kgf/mm ² , "D" (unqualified) means an average In the case of 0kgf/mm ² or more and less than 5kgf/mm ² .

(Evaluation of falling powder)

Sensory evaluation was performed by visual inspection. "A" (excellent) means that no powder fall is confirmed, "B" (good) means less powder fall, "C" (pass) indicates a little more powder fall, "D" (unqualified) ) Indicates a situation where a lot of powder falling occurs. A~C are practical grades.

(Evaluation of average interval)

As the ratio of the interval between each roughened layer, the convex part of each layer is determined in the image observed by the scanning electron microscope (SEM) from the vertical section, and the measurement is measured from here to the right Continuing 10 adjacent convex and convex intervals (vertex interval), calculate the ratio from the average value. In addition, the so-called spacing ratio (additional/vertical) refers to a value obtained by calculating the ratio of the spacing of the additional roughening layer to the spacing of the vertical roughening layer. Furthermore, the measurement of the interval between each convexity is shown in Figure 4, taking the interval between the apex of the convex part and the apex of the adjacent convex part confirmed by the above-mentioned vertical cross-sectional observation (the interval between the vertical roughening layer 6, the additional roughening layer For the average value of interval 7), the "average interval" is shown in Table 1. In addition, perform SEM observation on approximately 10 equal parts of the strip in the TD direction, and determine the line segment length of the outermost cross section (the total length of the line segment length of the outermost cross section) (A) and conductivity based on the obtained SEM image The line segment length (B) of the cross-section of the substrate, and the ratio (the total length of the line segment length of the outermost cross-section 9a(A) divided by the line segment length 8(B) of the conductive substrate cross-section is the value) (A/B) value. Show it in the table as "Surface Section Line Segment Length Ratio".

1‧‧‧Conductive substrate

2‧‧‧Vertical roughening layer

3‧‧‧Additional roughening layer

Claims (9)

A lead frame material having a roughened layer on a conductive substrate, characterized in that the roughened layer is composed of a plurality of roughened layers, and the roughened layer has at least one vertical layer in the vertical direction of the conductive substrate. A roughened layer, and further have at least one additional roughened layer on the upper layer of the vertical roughened layer. Among the concavities and convexities of the vertical roughened layer and the additional roughened layer, the vertical roughened layer The interval between the apexes of the adjacent protrusions is different from the interval between the apexes of the adjacent protrusions of the additional roughening layer; the line segment length (A) of the outermost layer section of the lead frame material and the line segment length (B) of the conductive substrate section The value of the ratio (A/B) is 1.2 or more and 4 or less. For example, the lead frame material of item 1 in the scope of patent application, wherein the conductive substrate is copper or copper alloy, iron or iron alloy, aluminum or aluminum alloy. For example, the lead frame material of item 1 or 2 of the scope of patent application, wherein the plurality of roughened layers are composed of two layers, and the first vertical roughened layer that is roughened in the vertical direction of the conductive substrate and the vertical roughened The second additional roughening layer above the layer, and the vertical roughening layer and the additional roughening layer have different compositions. Such as the lead frame material of item 3 of the scope of patent application, wherein the interval between the apexes of the convex portions of the second additional roughening layer is narrower than the interval between the apexes of the convex portions of the first vertical roughening layer. For example, the lead frame material of item 1 or 2 of the scope of patent application, wherein the composition of the vertical roughening layer is composed of copper or copper alloy. For example, the lead frame material of item 1 or 2 of the scope of patent application, wherein the composition of the additional roughening layer is composed of any one of nickel, nickel alloy, cobalt, and cobalt alloy. For example, the lead frame material of item 1 or 2 of the scope of patent application, wherein the conductive substrate has The vertical roughening layer that is roughened in the vertical direction, and has an additional roughening layer as the upper layer of the vertical roughening layer, and further the upper layer of the additional roughening layer has a single layer or a single layer on the entire surface or part of the lead frame material The plural layers are a surface layer composed of any one of palladium, palladium alloy, rhodium, rhodium alloy, ruthenium, ruthenium alloy, platinum, platinum alloy, iridium, iridium alloy, gold, gold alloy, silver, and silver alloy. A method for manufacturing a lead frame material, which is a method for manufacturing a lead frame material according to any one of items 1 to 7 of the scope of patent application, wherein either or both of the vertical roughening layer and the additional roughening layer It is formed by electroplating. A semiconductor package that uses a lead frame material of any one of items 1 to 7 in the scope of patent application.

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