KR20190096964A - Lead frame material, manufacturing method thereof and semiconductor package - Google Patents

Abstract

Harmonic including a conductive base 1 and at least one roughened layer 2 formed of a plurality of roughened particles projections 4 on at least one surface, directly or through an intermediate layer. The film 3 is provided, and the said projection 4 has the largest width when measured by the thickness direction cross section of the said roughening film 3 located in the said conductive base 1 side rather than the measurement position of the said largest width. The lead frame member 10 which has a shape which becomes 1 to 5 times compared with the minimum width when measured by the lower part.

Description

Lead frame material, manufacturing method thereof and semiconductor package

The present invention relates to a lead frame member suitable for use in a resin encapsulated semiconductor device formed by electrically connecting a semiconductor element and a lead frame having a surface treatment layer to each other and encapsulating them with a mold resin, and a manufacturing method thereof and a semiconductor package thereof. .

This type of resin-encapsulated semiconductor device has a structure in which a semiconductor device and a lead frame electrically connected to each other by a wire or the like are sealed with a mold resin. Such a resin-encapsulated semiconductor device is generally manufactured by surface treatment such as exterior plating on a lead frame, and forming a surface film with a Sn alloy such as a Sn-Pb alloy or a Sn-Bi alloy.

Therefore, in recent years, in order to simplify the assembly process and reduce the cost, plating of a specification that improves the wettability with the solder in mounting by soldering on the printed board or the like on the surface of the lead frame in advance (for example, Ni / Pd / Au) The lead frame (Pre-Plated Frame) which does the following has be employ | adopted (for example, refer patent document 1).

On the other hand, in order to improve the adhesiveness of the lead frame and mold resin in a resin-sealed semiconductor device, the technique of roughening the plating surface of a lead frame is proposed (for example, refer patent document 2).

The technique of roughening a plating surface is roughening plating to a lead frame and roughening the surface, so that (1) mold resin enters the unevenness of the roughened plating film and forms a strong mechanical joint (anchor effect), (2) mold It is expected to improve the chemical bonding as the contact area between the resin and the plating surface is improved.

By harmonizing the surface of the lead frame, the adhesion of the mold resin to the lead frame is improved, and peeling between the lead frame and the mold resin is suppressed, and as a result, the reliability of the resin-encapsulated semiconductor device can be improved.

Patent Document 1: Japanese Patent Application Laid-Open No. 4-115558 Patent Document 2: Japanese Patent Application Laid-Open No. 6-029439

By harmonizing the surface of a lead frame, the adhesiveness of the mold resin with respect to a lead frame can be improved reliably compared with the conventional resin encapsulated semiconductor device. However, in recent years, the level of demand for reliability has become more stringent than before, and the durability test of high temperature and high humidity, for example, when the high temperature and high humidity test is conducted under severe conditions of 168 hours in an environment of 85 ° C and 85% humidity In addition, it is necessary to pass the acceptance criteria of reliability. On the other hand, the conventional structure which just harmonized the surface of a lead frame like patent document 1 may have a clearance gap between resin and a lead frame, and may not pass the acceptance criterion of reliability. This is a resin-encapsulated semiconductor device, and as the package of QFN (Quad Flat Non-Leaded Package) type and Small Outline Package (SOP) type is used in recent years, the level of demand for adhesion of resin to lead frame has been increased. I can think of it. As described above, in the resin-encapsulated semiconductor device, the adhesiveness of the resin to the lead frame has been required to be further improved in that it is required to maintain good adhesiveness even under the severe conditions as described above.

An object of the present invention is to provide a lead frame member, a method for producing the same, and a semiconductor package having high reliability, which are suitable for forming a lead frame surface capable of maintaining good resin adhesion even when subjected to high temperature and high humidity test under particularly severe conditions described above. do.

MEANS TO SOLVE THE PROBLEM The present inventors examined in order to solve the said subject, and think that the cross-sectional shape of the protrusion of the roughening particle which comprises the roughening layer of the roughening film formed on a conductive base greatly affects resin adhesiveness, and forms it on the surface of a lead frame material. It was examined whether the good adhesiveness caused by the so-called anchor effect caused by the filling of resin on the uneven surface (especially the recessed portion) caused by a projection can be maintained even when the high temperature and high humidity test was performed under the above-mentioned harsh conditions. .

And the inventors of the present invention, the lower portion where the maximum width when the projection forming the roughening layer of the roughening film formed on the conductive base in the thickness direction cross section of the roughening film is located on the conductive base side than the measurement position of the maximum width Shearing of the resin which is likely to occur due to concentration of stress due to expansion or contraction of the resin, particularly at the location of the minimum width of the protrusion of the roughened particles, by controlling to have a shape that is 1 to 5 times the minimum width measured at The knowledge that the peeling phenomenon by can be suppressed effectively was acquired. As a result, good adhesion due to the anchor effect can be maximized by the roughening layer, and furthermore, by controlling the projections forming the roughening layer in the above-described shape, a durability test of high temperature and high humidity, for example, which has not been tolerated conventionally, for example, temperature It was found that even when the high temperature and high humidity test was carried out under the harsh conditions of standing at 168 hours in an environment of 85 ° C. and 85% humidity, good resin adhesion to the lead frame could be maintained.

That is, the summary structure of this invention is as follows.

(1) A roughening film including a conductive base and at least one roughened layer formed of projections of a plurality of roughened particles on at least one surface of the conductive base directly or via an intermediate layer,

The projections are shaped such that the maximum width when measured in the thickness direction cross section of the roughened film is 1 to 5 times larger than the minimum width when measured at the lower portion located on the conductive base side than the measurement position of the maximum width. Lead frame member having.

(2) The lead frame material according to the above (1), wherein the conductive base is copper, copper alloy, iron, iron alloy, aluminum, or aluminum alloy.

(3) The roughened layer may be copper, copper alloy, nickel, nickel alloy, palladium, palladium alloy, silver, silver alloy, tin, tin alloy, zinc, zinc alloy, rhodium, rhodium alloy, ruthenium, ruthenium alloy, iridium and The lead frame material as described in said (1) or (2) containing the metal or alloy selected from the group of an iridium alloy.

(4) A surface coating including at least one surface coating layer is further provided on at least a part of the surface of the roughening coating, wherein the surface coating layer is a palladium, palladium alloy, rhodium, rhodium alloy, ruthenium, ruthenium alloy, The lead frame material in any one of said (1)-(3) containing the metal or alloy selected from the group of a platinum, a platinum alloy, an iridium, an iridium alloy, gold, a gold alloy, silver, and a silver alloy.

(5) The lead frame material according to the above (4), wherein the intermediate layer is nickel, a nickel alloy, cobalt, a cobalt alloy, copper, or a copper alloy.

(6) forming a roughened film including at least one roughened layer formed of projections of a plurality of roughened particles by electroplating on at least one surface of the conductive base, directly or through an intermediate layer, The projections are shaped such that the maximum width when measured in the thickness direction cross section of the roughened film is 1 to 5 times larger than the minimum width when measured at the lower portion located on the conductive base side than the measurement position of the maximum width. Method for producing a lead frame member having a.

(7) The semiconductor package which has the lead frame material in any one of said (1)-(5).

The lead frame material of this invention is equipped with the roughening film which consists of a conductive base and at least 1st roughening layer formed from the protrusion of some roughening particle on the at least one surface of the said conductive base directly or via an intermediate | middle layer, The said The projection has a shape in which the maximum width when measured in the thickness direction cross section of the roughened film is 1 to 5 times larger than the minimum width when measured at the lower portion located on the conductive base side than the measurement position of the maximum width. By having a high temperature and high humidity durability test, for example, even if the high temperature and high humidity test is carried out under the harsh conditions of 168 hours in a temperature of 85 ° C. and an humidity of 85%, the good resin adhesion to the lead frame is maintained almost without deterioration. In this way, the semiconductor package constructed using this lead frame material can realize high reliability.

1 is a schematic cross-sectional view of a representative lead frame member according to the present invention.
2 is a diagram for explaining a method of calculating the specific surface area of a roughened layer.
FIG. 3 is a diagram for explaining the maximum width Wmax and the minimum width Wmin of the protrusions constituting the roughened layer of one layer.
4 is a schematic cross-sectional view of another lead frame member according to the present invention.
FIG. 5 is a diagram for explaining the maximum width Wmax and the minimum width Wmin of the protrusions constituting the two-layer roughening layer. FIG.

Next, the lead frame material which concerns on this invention is demonstrated below, referring drawings for example of specific embodiment. Fig. 1 shows a schematic cross section of a representative lead frame member according to the present invention, in which 1 is a conductive base, 2 is a roughening layer, 3 is a rough coating, 4 is a projection, and 10 is a lead frame member. The lead frame material 10 of this invention is equipped with the roughening film 3 containing the electroconductive base 1 and the at least 1 roughening layer 2.

(Conductive gas)

The conductive base 1 may be a material having conductivity, and examples thereof include copper, copper alloys, iron, iron alloys, aluminum or aluminum alloys, and copper alloys, iron alloys or aluminum alloys are preferable. . The lead frame member is required to have a strength that can withstand deformation, such as bending, at the time of joining with a semiconductor element, and the use of a copper alloy having a good balance of electrical conductivity and strength is particularly preferable. Above all, as the copper alloy, for example, "C14410 (Cu-0.15Sn, manufactured by Furukawa Denki Kogyo Co., Ltd., trade name: EFTEC (registered trademark) -3)", which is a CDA (Copper Development Association) publication alloy, and "C19400 (Cu-Fe). System alloy material, Cu-2.3Fe-0.03P-0.15Zn) "," C18045 (Cu-0.3Cr-0.25Sn-0.2Zn, the product made by Furukawa Denki Kogyo, a brand name: EFTEC (registered trademark) -64T) "," C50710 (Cu-2.0Sn-0.2Ni-0.05P), Furukawa Denki High School Co., Ltd., brand name: MF202, "C70250 (Cu-3Ni-0.65Si-0.15 Mg), Furukawa Denki High School Co., Ltd., brand name: EFTEC (registered trademark)- 7025 ”, etc. are mentioned. In addition, all the units of the number shown immediately before each element are "mass%." Like these copper alloys, a tensile strength of 350 to 800 N / mm ² , preferably 500 to 800 N / mm ² , and a material of copper alloy having a conductivity of 30 to 90% IACS, preferably 50 to 80% IACS is obtained. It is preferable to use. In addition, the said "% IACS" shows the conductivity when the resistivity of the International Annealed Copper Standard is 1.7241 x 10 ^-8 Ωm at 100% IACS. For example, the conductivity of "50% IACS" is universal. It means that it is 50% of the conductivity of the standard linkage. Moreover, in the case of an iron alloy, 42 alloys (Fe-42 mass% Ni), stainless steel, etc. are mentioned, for example. The electroconductive base 1 containing such an iron alloy is not so high in conductivity, but the conductivity is not so demanded, and can be applied to the lead frame member 10 for the purpose of transmitting electric signals. Furthermore, in the case of an aluminum alloy, Al-Mg type alloys, such as A5052, are mentioned, for example. Since the resin-sealed semiconductor device tends to be filled with heat by the mold resin, it is important to dissipate heat inside the conductive gas along the conductive base. In the present invention, by forming the roughened film on the surface of the conductive base, the heat dissipation effect can be improved as compared with the case where the roughened film is not formed, and the thickness of the conductive base can be reduced to 0.05 mm. When the thickness of the conductive base is thinner than 0.05 mm, sufficient heat dissipation cannot be achieved, and when the thickness of the conductive base is 2 mm or more, miniaturization of the semiconductor device cannot be achieved. For this reason, 0.05-2 mm is preferable and, as for the thickness of the electroconductive base 1, 0.1-1 mm is more preferable.

(Harmonic film)

The roughened film 3 is formed on at least one surface of the conductive base 1 by at least one roughened layer 2 formed of the projections 4 of the plurality of roughened particles, either directly or through an intermediate layer (not shown). It consists of. In addition, although the roughening film 3 should just be comprised from the at least one roughening layer 2, in consideration of the complexity of a manufacturing process, etc., it is preferable to comprise the roughening layer 2 of 1-3 layers. The formation method of the roughening film 3 is a roughening layer of the 2nd layer from which one or more factors, such as a composition and formation conditions, differ from the 1st roughening layer 2-1 after formation of the 1st layer of roughening layer 2-1. By forming (2-2) by so-called multiple roughening by laminating (1-2) on the first roughening layer 2-1, the specific surface area can be effectively increased with a relatively thin film thickness, which is more preferable (Fig. 4). Reference). In addition, in this invention, the film thickness of the roughening film 3 is not measured locally, but is at least 0.2 mm of collimator diameter by fluorescent X-ray method (for example, film thickness measuring apparatuses, such as SFT9400 (brand name) by SII)). It is assumed that it is expressed by the average film thickness when measured by arbitrary three points. In addition, when the roughening film 3 is comprised from the some roughening layer 2, it is assumed that the total thickness of all the layers is defined as the thickness of the roughening film 3. In addition, the film thickness of the roughening film 3 does not have a restriction | limiting in particular, The larger the film thickness, there exists a tendency for the unevenness | corrugation by roughening to become large. Therefore, in order to enlarge a roughening shape, the lower limit of the film thickness of the roughening film 3 becomes like this. Preferably it is 0.2 micrometer or more, More preferably, it is 0.5 micrometer or more, More preferably, it is 0.8 micrometer or more. On the other hand, when the film thickness of the roughening film 3 exceeds 3 micrometers, there exists a possibility that the fall of the roughening film 3 at the time of conveyance, so-called "powdering" may increase. For this reason, the upper limit of the film thickness of the roughening film 3 becomes like this. Preferably it is 3 micrometers or less, More preferably, it is 2 micrometers or less, More preferably, it is 1.5 micrometers or less.

[Harmonized layer]

The roughened layer 2 is formed of the projections 4 of the plurality of roughened particles. Examples of the method for forming the roughened layer 2 include various methods such as wet plating and dry plating, but it is particularly preferable to form by electroplating from the viewpoint of being easy and inexpensive to form. The roughening layer 2 is, for example, copper, copper alloy, nickel, nickel alloy, palladium, palladium alloy, silver, silver alloy, tin, tin alloy, zinc, zinc alloy, rhodium, rhodium alloy, ruthenium, ruthenium alloy, It is preferred to include a metal or alloy selected from the group of iridium and iridium alloys. The roughening layer 2 is a copper, copper alloy, nickel or nickel from the viewpoint of improving the adhesion to the surface coating, especially when further forming a surface coating (not shown) described later on the roughening coating 3. It is more preferable to include an alloy. Examples of the copper alloy include copper-tin alloys, copper-zinc alloys, and nickel alloys such as nickel-zinc alloys and nickel-tin alloys.

And the main characteristic in the structure of this invention is aiming at optimizing the cross-sectional shape of the projection 4 of the roughening particle which comprises the roughening layer 2, More specifically, as shown in FIG. The maximum width Wmax when water 4 is measured in the thickness direction cross section of the roughening film 3 is the minimum width Wmin when measured in the lower part located in the conductive base 1 side rather than the Wmax measurement position of the said largest width. It is to control so that it may have a shape 1 to 5 times compared with.

The inventors have studied diligently and, if the roughened layer is formed with the same surface roughness, the shear strength (bonding strength) of the resin in the shear test is high, and good resin adhesiveness can be obtained, but at a high temperature. After high temperature and humidity test, for example, under high temperature and high humidity test under conditions of 168 hours in a temperature of 85 ° C. and a humidity of 85%, the roughened layer having the same surface roughness is greatly reduced in shear strength, and good resin adhesion. It turns out that there can't be. As a result of further investigation on this point, it is found that the cross-sectional shape of the projections of the roughened particles forming the roughened layer is greatly influenced. In particular, the stress due to the thermal expansion or contraction of the resin is reduced at the minimum width of the projections. It was found that the adhesion was lowered due to concentration.

For this reason, the present inventors conducted further examination, and the ratio of the maximum width and minimum width of the protrusion of the roughening particle which forms the roughening layer of a roughening film is 1-5, ie, a projection is made in the thickness direction cross section of a roughening film. Harmonicity having the same degree of surface roughness by controlling the maximum width when measured to have a shape that is 1 to 5 times larger than the minimum width when measured at the lower portion located on the conductive base side than the measured position of the maximum width. Even in the layer, the shear strength (bond strength) of the resin hardly decreases even after performing the high temperature and high humidity durability test, for example, the high temperature and high humidity test under severe conditions left at 168 hours in an environment of 85 ° C. and 85% humidity. It discovered that resin adhesiveness can be maintained.

In the projections, the maximum width is one times the minimum width, indicating that the maximum width and the minimum width are the same, and examples of the shape of the projections include a case of a substantially cylindrical shape or a footnote shape. On the other hand, if the maximum width of the projections exceeds 5 times the minimum width, the concentration of stress due to expansion or contraction of the resin increases at the location of the minimum width of the projections forming the roughened layer, so that the anchor effect cannot be effectively exhibited. Breaking occurs easily at the location of the minimum width of the projection. For this reason, the protrusion has a maximum width of 1 to 5 times the minimum width. In addition, not only the mold resin exerts an anchor effect but also makes it difficult to cause breakage at the minimum portion of the protrusions in which the resin forms the roughening layer, thereby improving the shear strength with respect to the lead frame material, as well as in the vertical direction. When it is necessary to further improve the tensile strength, the ratio of the maximum width to the minimum width of the projections is preferably 1.1 to 4.9 times, more preferably 1.2 to 4.8 times, and even more preferably 1.5 to 4.0 times. It is preferable and it is most preferable to set it as 1.5-3.0 times. Moreover, although it is the shape of the surface in a projection, it may be sharp, pointed, round, and smooth, and the ratio of the maximum width and minimum width of a projection is important.

<About definition of maximum width and minimum width of projection>

The maximum width and the minimum width of the projections in the present invention are produced by processing a lead frame member on which a roughened layer is formed, for example, by a method such as Focused Ion Beam (FIB) or mechanical polishing. Cross-sectional observation is performed by an optical microscope, a scanning electron microscope, or the like on the roughened layer of the cross-sectional sample, and the line segments are moved in parallel from the surface of the conductive base toward the roughened layer surface, and the plurality of projections forming the roughened layer The width is measured for each projection to determine the maximum value (maximum width) Wmax and the minimum value (minimum width) Wmin. In more detail, as shown in FIG. 3, a line is drawn in the direction of a roughening layer from the conductive base 1, and a line parallel to a base (parallel line) is scanned in the direction toward the conductive base 1 from the apex. The maximum value of the projections 4 at the time of making it the maximum width was made into Wmax, and the minimum value of the projections 4 when the parallel line was again scanned from the position of the maximum width Wmax toward the conductive base 1 was further determined. The width shown is determined as Wmin as the minimum width. And in this invention, the value of the ratio Wmax / Wmin needs to be 1-5. In addition, the minimum width Wmin of the projection 4 is a lower portion located on the conductive base 1 side than the measurement position of the maximum width Wmax of the projection 4 when measured in the thickness direction cross section of the roughening film 3. The minimum width, Wmin, measured at. This is based on the knowledge that the shear strength depends on the width of the lower portion (proximal portion) of the projection 4 located on the conductive base 1 side in the shear test. Further, the projections 4 are observed at various positions of the roughened layer 2 in order to observe any cross section. Since the roughening layer 2 is generally formed three-dimensionally basically, as the roughening layer 2 which measures the maximum width Wmax and the minimum width Wmin of the projection 4, one roughened layer 2 ) Or as two or more roughened layers (for example, two roughened layers 2-1 and 2-2 in FIG. 5), the maximum width Wmax of the projection 4 is shown. And the case where the measurement of the minimum width Wmin is possible, besides being a roughening layer of two or more layers, for example, when the outermost surface contour of the roughening film 3 is not clear, or from the conductive base 1 In the case of the roughened layer 2 which can be seen, it is set as the roughened layer which cannot be called a measurement object in this invention. According to these techniques, for each of the ten protrusions 4 present in one roughened layer 2 in any cross section, the maximum width Wmax and the minimum width Wmin are measured, and the ratio Wmax / to the minimum width Wmin of the maximum width Wmax is measured. Wmin is computed and the lead frame material 10 which has the roughening layer 2 whose average value of these ratios is 1 to 5 times is defined as the lead frame material of this invention.

<About minimum width of protrusion and gap between protrusions>

In addition, although it does not specifically define about the magnitude | size of the minimum width Wmin of the protrusion 4 which forms the roughening layer 2 in this invention, If the minimum width Wmin is too small, resin will be the protrusion of the roughening layer 2, It tends to be difficult to flow in the gap between the water 4 and 4, and on the other hand, when the minimum width Wmin is too large, the effect of increasing the shear strength tends to be small. For this reason, it is preferable that the minimum width Wmin of the projection 4 is in the range of 0.2 μm to 3 μm, and more preferably in the range of 0.5 μm to 1 μm. Moreover, although it does not specifically limit about the space | interval of protrusions 4 and 4, The range of 0.2-20 micrometers is preferable as an average space | interval of the vertices of protrusions 4 and 4, and the range of 0.5 micrometer-10 micrometers is It is more preferable.

<About specific surface area of harmonic layer>

The lead frame member 10 of the present invention first has a roughened layer 2 with respect to a conductive substrate (hereinafter, also referred to simply as a "gas"). It is preferable that the roughening layer 2 has a specific surface area of 110% or more. This is because when the specific surface area is less than 110%, the anchoring effect cannot be sufficiently obtained. The upper limit of the specific surface area is not particularly limited. However, when the specific surface area is too large, the roughness of the roughened surface becomes too large and the roughened layer easily falls off. Therefore, the specific surface area is preferably 500% or less.

In addition, as a calculation method of a specific surface area, as shown in the cross section of the lead frame material 10 in FIG. 2, the line segment length of the outermost layer of the roughening film 3 is shown from the cross section of the lead frame material 10 (FIG. The percentage of ratio A / B obtained by dividing by dashed line A in FIG. 2 by the (straight line) length of the surface of the conductive base 1 (bold solid line B in FIG. 2) becomes the specific surface area (%). It can measure using a measuring apparatus (for example, Bruker axs company), such as a non-contact interference microscope. In addition, the formation location of the roughening layer in this invention should just be formed in at least one part of the part to be resin-molded, and the roughening layer 2 may be formed in part as well as the whole surface process. For example, it is preferable that the lead frame material 10 is at least 1/5 or more of the part by which resin mold is carried out, More preferably, it is formed in the area of 1/2 or more, and can exhibit an adhesive improvement effect. It is most preferable that the roughening layer 2 is formed in the whole surface to be resin-molded. As the shape of the roughening layer 2 provided in this part, it is possible to take various forms, such as stripe shape, a point shape, and ring shape. In addition, in the product whose resin mold has only one side, it is also possible to form the roughening layer 2 only on one side, for example.

(Middle floor)

In addition, the lead frame member 10 of the present invention is an intermediate layer between the conductive base 1 and the roughened film 3, for example, to suppress diffusion of compositional components constituting the conductive base 1 and to improve adhesion. May be formed. The intermediate layer may be nickel, nickel alloy, cobalt, cobalt alloy, copper or copper alloy, for example.

(Surface coating)

In addition, the lead frame member 10 of the present invention preferably further includes a surface coating including at least one surface coating layer on at least part of the surface of the roughening coating 3 directly or through an intermediate layer. The surface coating layer includes a metal or an alloy selected from the group of palladium, palladium alloy, rhodium, rhodium alloy, ruthenium, ruthenium alloy, platinum, platinum alloy, iridium, iridium alloy, gold, gold alloy, silver and silver alloy desirable.

[Surface coating layer]

As various alloys constituting the surface coating layer, for example, a palladium alloy is a palladium-silver alloy, a rhodium alloy is a rhodium-palladium alloy, a ruthenium alloy is a ruthenium-iridium alloy, a platinum alloy is a platinum-gold alloy, and an iridium alloy is platinum-iridium As an alloy and a gold alloy, a gold-silver alloy, a silver-silver alloy, etc. are mentioned. Although one type of surface coating may be sufficient, two or more layers are preferable. As typical layer constitutions in the case where the surface coating layers constituting the surface coating are two or more layers, Pd / Au, Rh / Au, Pd / Ag / Au, Pd / Rh / Au, Ru in the laminating order from the roughening coating 3 side. / Pd / Au etc. are mentioned. By forming the surface coating layer on the roughening film in this way, the heat resistance of the heat generation of the lead frame is improved, and the strength of the projections of the roughening particles forming the roughening layer of the roughening coating is improved, and the breakage of the projections is further prevented. It can exert more anchor effect. Moreover, from a viewpoint of improving adhesiveness with respect to a surface coating, it is more preferable that a roughening layer is two layers of Pd / Au or two layers of Rh / Au with respect to two layers of copper and nickel, As a laminated constitution of a roughening layer The lower roughening layer is copper, and the upper roughening layer is two layers of nickel. The lower surface coating layer is Pd, the upper surface coating layer is two layers of Au, or the lower surface coating layer is Rh, and the upper surface coating layer is Au. It is further more preferable that it is 2 layers of. If the film thickness of these surface coatings is too thick, the surface roughness of the roughening film 3 may be buried, and the effect of the present invention described above may not be sufficiently exhibited. In addition, the surface film is mainly composed of precious metal materials. There is a possibility to call a rise. For this reason, it is preferable that it is 1 micrometer or less as a total film thickness (film thickness of surface coating) of the laminated surface coating layer, and, as for the film thickness of each surface coating layer, it is more preferable that it is 0.03 or less.

(About a manufacturing method of the lead frame material)

Next, the manufacturing method of the lead frame material 10 of this invention is demonstrated below. The conductive base 1 is prepared, and a cathode electrolytic degreasing step and a pickling step are performed on the conductive base 1. Subsequently, after forming an intermediate | middle layer by electroplating as needed, the roughening film 3 containing the at least 1 roughening layer 2 is formed by electroplating, and then again by electroplating as needed. The lead frame material 10 can be manufactured by forming the surface film containing at least one surface coating layer. As representative examples of specific manufacturing conditions, cathodic electrolytic degreasing conditions in Table 1, pickling conditions in Table 2, formation conditions of various intermediate layers in Table 3, formation conditions of various roughening layers 2 in Table 4, and various in Table 5 Formation conditions of a surface coating layer are shown, respectively. In the manufacturing method of the lead frame material 10 mentioned above, the case where all the intermediate | middle layer, the roughening layer 2, and the surface coating layer were manufactured by electroplating was illustrated. The roughened layer 2 is preferably formed by an electroplating method in that the shape of the projection can be controlled relatively easily by current density, stirring, temperature, processing time and the like, and is also preferably formed by the electroplating method for the intermediate layer or the surface coating layer. Although it is preferable to form according to the wet plating method as described above from a viewpoint of productivity, you may manufacture by a dry plating method or another manufacturing method, and there is no limitation in particular.

Example

EMBODIMENT OF THE INVENTION Hereinafter, although this invention is demonstrated in more detail based on an Example, this invention is not limited to these. Various electroconductive bases shown in Table 6 of the plate thickness 0.2mm cut | disconnected to the test piece size 40mm * 40mm previously were prepared, and cathodic electrolytic degreasing was performed on the conditions shown in Table 1 mentioned above. Subsequently, after pickling of a conductive base under the conditions shown in Table 2, at least one roughened layer was formed on the surface of the conductive base in the layer configuration shown in Table 6 to obtain a test piece of the lead frame member. In addition, formation of a roughening layer controlled not only the specific surface area but the ratio with respect to the minimum width | variety of the largest width in the protrusion of the roughening layer in a cross section. In Examples 1-30, the roughening film forms an upper roughening layer further on the lower roughening layer about Examples 11-13, and is comprised by two roughening layers, and about Examples 22-24, roughening with a conductive base An intermediate layer is further formed between the coatings, and in Examples 29 and 30, the roughening coating is formed on the lower roughening layer in addition to the upper roughening layer, and is composed of two roughening layers. The surface coating including two layers of the coating layer is further formed. For reference, as Comparative Example 1, although the specific surface area of the roughened layer is very large (550%), the ratio of the minimum width of the maximum width of the protrusions forming the roughened layer is not controlled (5.2 times). The test piece of in lead frame material was produced.

In each of the above test pieces, the resin mold was injection-molded under a condition of a holding time of 90 seconds and an injection pressure of 6.865 MPa after a mold temperature of 130 ° C. in a transfer mold test apparatus (trade name: Model FTS) manufactured by Kotaki Seiki Co., Ltd. ^Two purine-like test pieces were formed. Each test piece was put into the high temperature, high humidity test (85 degreeC, 85% RH, hold | maintain for 168 hours), and the test piece was evaluated on the resin adhesiveness and the powder fallability on the conditions shown below. The evaluation results are shown in Table 7.

(Resin adhesion evaluation)

Evaluation resin: G630L, Sumitomo Bakelite company (brand name)

Evaluation condition: A device: 4000Plus, product made in Nordson Advanced Technology Co., Ltd. (brand name),

   Load cell: 50kg

   Measuring range: 10 kg

   Test speed: 100 μm / s

   Test height: 10μm

Table 7 shows the evaluation results of the resin adhesiveness. In addition, evaluation of resin adhesiveness shown in Table 7 is called "A" in the case that shear strength (peel strength) is 9.8 MPa or more on average, and is excellent in resin adhesiveness, and shear strength (peel strength) is 4.9 MPa or more 9.8 on average. The case where it was less than MPa was called "B" because resin adhesiveness was favorable, and the case where shear strength (peel strength) was less than 4.9 MPa on average was shown as "C" because resin adhesiveness was inferior. Resin adhesiveness was evaluated by measuring both "initial shear strength" and "shear strength after a high temperature, high humidity test." "The shear strength after a high temperature, high humidity test" is a value after leaving each test piece to mold for 168 hours in the environment of 85 degreeC and 85% of humidity after resin-molding. In addition, "initial shear strength" is a shear strength immediately after resin-molding each test piece (before a high temperature, high humidity test).

(Powder drop evaluation)

Powder degradability evaluated sensitivity visually. The evaluation results are shown in Table 7. In addition, the powder falling property shown in Table 7 is called "A (excellent)" when the powder fall-off from the surface cannot be recognized, "B (good)" when a little powder fall occurs, and powder fall is The case where it generate | occur | produces very much is shown as "C (impossible)", and "A" and "B" are the levels used practically.

From the evaluation result of Table 7, all of Examples 1-30 have initial shear strength and the shear strength after high-temperature, high-humidity test of "A" or "B", and maintain favorable resin adhesiveness, and also the powder fall-off property is "A" or It was the level used for practical use in "B". In contrast, although the specific surface area of the roughened layer is very large at 550%, Comparative Example 1, which is outside the scope of the present invention (5.2 times) without controlling the ratio to the minimum width of the maximum width of the protrusions forming the roughened layer, Regarding the initial shear strength, the resin adhesiveness was excellent in "A", but the shear strength after the high temperature and high humidity test became "C", the resin adhesiveness deteriorated largely, and the powder fall-off property also dropped to "C", and it was not a level used for practical use. .

The lead frame member of the present invention almost deteriorates good resin adhesion to the lead frame even when subjected to a high temperature and high humidity durability test, for example, in a high temperature and high humidity test under severe conditions of 168 hours in an environment of 85 ° C. and 85% humidity. It can hold | maintain without making it, and the semiconductor package comprised using this lead frame material can implement | achieve high reliability.

1: conductive substrate
2: roughened layer
2-1: 1st harmonic layer (harmonic layer of the 1st layer from a base material side)
2-2: 2nd harmonic layer (2nd harmonic layer from base material side)
3, 3-1: roughened film
4, 4-1: projection
10, 10A: lead frame material
A: cross-sectional line length of the outermost surface of the roughening film
B: cross-sectional line length of the surface of the conductive substrate

Claims (7)

With a conductive base,
A roughened film comprising at least one roughened layer formed on at least one side of the conductive substrate, either directly or through a middle layer, of a plurality of roughened particles projections; ,
The projections are shaped such that the maximum width when measured in the thickness direction cross section of the roughened film is 1 to 5 times larger than the minimum width when measured at the lower portion located on the conductive base side than the measurement position of the maximum width. Lead frame material having a.
The lead frame material according to claim 1, wherein the conductive base is copper, copper alloy, iron, iron alloy, aluminum or aluminum alloy.
The said roughening layer is copper, copper alloy, nickel, nickel alloy, palladium, palladium alloy, silver, silver alloy, tin, tin alloy, zinc, zinc alloy, rhodium, rhodium alloy, ruthenium, ruthenium. A lead frame material comprising a metal or an alloy selected from the group of alloys, iridium and iridium alloys.
The surface coating including at least one surface coating layer is further provided on at least one part of the surface of the said roughening film, The said surface coating layer is a palladium, a palladium alloy, rhodium, A lead frame material comprising a metal or an alloy selected from the group of rhodium alloys, ruthenium, ruthenium alloys, platinum, platinum alloys, iridium, iridium alloys, gold, gold alloys, silver and silver alloys.
The lead frame material according to claim 4, wherein the intermediate layer is nickel, nickel alloy, cobalt, cobalt alloy, copper or copper alloy.
Forming a roughened film including at least one roughened layer formed of projections of a plurality of roughened particles by electroplating on at least one side of the conductive base, directly or through an intermediate layer,
The projections are shaped such that the maximum width when measured in the thickness direction cross section of the roughened film is 1 to 5 times larger than the minimum width when measured at the lower portion located on the conductive base side than the measurement position of the maximum width. Method for producing a lead frame member having a.
The semiconductor package which has the lead frame material in any one of Claims 1-5.

Images