TW201803065A - Lead frame material and method for producing same - Google Patents

Abstract

To provide: a lead frame material which is suitable for producing a lead frame that is able to have improved adhesion to resins in a high-temperature high-humidity environment, said improved adhesion to resins having been required recently; and a method for producing this lead frame material. A lead frame material which has a roughened layer (2) on a conductive base (1), and wherein: the roughened layer is in a roughened state having a specific surface area of 110% or more; an oxide film (3) is provided on the outermost surface of the roughened layer; and the oxide film has a thickness of from 10 nm to 100 nm (inclusive). A method for producing this lead frame material; and a semiconductor package which uses this lead frame material.

Description

Lead frame material and manufacturing method thereof

The present invention relates to a lead frame material and a manufacturing method thereof. The lead frame material is used for electrically connecting a semiconductor element and a lead frame having a plating layer to each other and sealing the same with a mold resin. Resin-sealed semiconductor device.

Such a resin-sealed semiconductor device is formed by sealing a semiconductor element and a lead frame electrically connected to each other by a lead wire or the like with a mold resin. In such a resin-sealed semiconductor device, it is mainstream that lead frames are coated with exterior plating such as Sn-Pb or Sn-Bi.

Here, in recent years, in order to simplify the assembly steps and reduce costs, a lead frame (Pre-Plated Frame (for example, Ni / Pd / Au) plated with a method such as Ni / Pd / Au) which has been previously applied to the surface of the lead frame has been used. Pre-plated frame), hereinafter abbreviated as PPP): improves the wettability with solder when it is mounted on a printed circuit board using solder or the like (see, for example, Patent Document 1).

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

These techniques for roughening the plating surface are intended to roughen the plating surface of the lead frame, (1) the effect of increasing the bonding area between the lead frame and the mold resin, and (2) The effect (i.e., the alignment effect) of the stamping resin becomes easy to bite the unevenness of the roughened plating film.

By doing so, it is possible to improve the adhesion of the lead frame to the mold resin, prevent the peeling between the lead frame and the mold resin, and improve the reliability of the resin-sealed semiconductor device.

[Patent Document 1] Japanese Patent Laid-Open No. 4-115558

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

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

These roughened platings using shapes can indeed improve the resin adhesion compared to previous ones. However, it is known from time to time that a level of high reliability is required in recent years, for example, a gap between the resin and the lead frame is generated after 168 hours under an environment of a temperature of 85 ° C and a humidity of 85%. It is thought that the reason is that the packages such as QFN (Quad Flat Non-Leaded Package) and SOP (Small Outline Package) types, which were not commonly used before, have been widely used, so that The degree of requirements for tightness is even higher. Therefore, we can see that there is still room for improvement.

An object of the present invention is to provide a lead frame material suitable for producing a lead frame which can improve resin adhesion in high temperature and high humidity environments required in recent years, and a method for manufacturing the same.

The present inventors have made intensive research and development on the above-mentioned conventional problems, and as a result, they have focused on the oxidation state of the roughened plating formed on the conductive substrate. The alignment effect of the resin has also been studied intensively on the method of chemically forming a bonding state with the resin. As a result, it was found that by controlling the thickness of the oxide film on the surface of the roughened layer formed on the substrate to 10 nm to 100 nm, not only the alignment effect, but also the state of chemical bonding with the resin can be formed. When it is set to 110% or more, the resin adhesion can be significantly improved compared with the past, and the resin adhesion can be ensured in the high temperature and high humidity test. The present invention has been 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, the roughened layer being in a roughened state with a specific surface area of 110% or more, and having an oxide film provided on the outermost surface of the roughened layer, the oxide film The thickness is 10 nm or more and 100 nm or less.

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

(3) The lead frame material according to (1) or (2), wherein the roughened layer is made of copper, copper alloy, nickel, nickel alloy, palladium, palladium alloy, silver, silver alloy, tin, tin alloy, Any one of zinc, zinc alloy, rhodium, rhodium alloy, ruthenium, ruthenium alloy, iridium, or iridium alloy.

(4) The lead frame material according to any one of (1) to (3), wherein the roughened layer is a single layer or a plurality of layers.

(5) The lead frame material according to any one of (1) to (4), wherein the conductive substrate has a roughened layer, and a single layer or a plurality of layers made of palladium, A surface layer made of any of palladium alloy, rhodium, rhodium alloy, ruthenium, ruthenium alloy, platinum, platinum alloy, iridium, iridium alloy, gold, gold alloy, silver, or silver alloy is used as the upper layer of the roughened layer.

(6) The method for producing a lead frame material according to any one of (1) to (5), wherein the roughened layer is formed by electroplating.

(7) A semiconductor package using the lead frame material according to any one of (1) to (5).

The inventors have found that by setting the specific surface area of the roughened layer formed on the conductive substrate to be 110% or more, and controlling the thickness of the oxide film on the surface to 10 nm to 100 nm, not only the alignment effect, but also good Form a chemical bond with the resin. As a result, the high-temperature and high-humidity adhesiveness of conventional resins which cannot be tolerated can be obtained. For example, even in a high-temperature and high-humidity environment where the temperature is 85 ° C and 85% for 168 hours, the generation between the lead frame material and the resin can be greatly suppressed The gap can obtain excellent resin adhesion.

The above and other features and advantages of the present invention are appropriately referred to the accompanying drawings, which should be more apparent from the following description.

1‧‧‧ conductive substrate

2‧‧‧ Roughened layer

2-1‧‧‧The first roughened layer (the roughened layer of the first layer from the substrate side)

2-2‧‧‧ 2nd roughened layer (2nd roughened layer from the substrate side)

3‧‧‧ oxide film

A‧‧‧ the length of the most superficial segment

B‧‧‧ the length of the segment of the substrate (straight)

FIG. 1 is a schematic cross-sectional view of a lead frame according to the present invention. A schematic diagram showing that an oxide film (3) with a coating thickness of 10 to 100 nm is formed on the surface of the conductive substrate (1) where the roughened layer (2) is formed.

Fig. 2 is a schematic sectional view showing a specific surface area of the present invention. Although the cross-sectional view is two-dimensional, the value obtained by dividing the length of the topmost line segment (A) by the length of the topmost straight line (B) is the specific surface area, which can be measured using, for example, a non-contact interference microscope. The specific surface area was obtained with A / B shown in the figure.

FIG. 3 is an example of a different form of the example of the present invention, and is a schematic cross-sectional view: a first roughened layer (2-1) is formed on the conductive substrate (1), and a second roughened layer is formed on the upper layer; The roughened layer (2-2) has an oxide film (3) formed on the surface of the roughened layer of the second layer at 10 to 100 nm.

(About the specific surface area of the roughened layer)

According to the present invention, first, a conductive substrate (hereinafter simply referred to as a substrate) is provided with a roughened layer. This roughened layer is a roughened layer having a specific surface area of 110% or more when the specific surface area is defined by the following formula (refer to FIG. 2 and obtained by A / B in the figure).

Specific surface area (%) = {(surface area of the surface of the roughened layer) / (surface area in the case of a flat surface)} × 100

The reason is that if the specific surface area is less than 110%, the alignment effect cannot be obtained sufficiently. Although the upper limit is not particularly limited, if it is too large, the roughened unevenness becomes too large and the roughened layer tends to fall off, so it is preferably 250% or less. In addition, by controlling the oxide film described below, even if the specific surface area of the roughened layer that had to be formed in the past is reduced, the same resin adhesion as in the past can be obtained. Therefore, the specific surface area is more preferably 120 to 200%.

As a specific surface area measurement method, the surface area of the surface of the roughened layer is measured by a measurement device such as a non-contact interference microscope (for example, manufactured by Bruker AXS Co., Ltd.), and the specific surface area is calculated by dividing by the area of the measurement area.

(About the oxide film thickness of the roughened layer)

In the roughened layer of the present invention, an oxide film is formed on the surface layer to a thickness of 10 to 100 nm. The naturally formed oxide film usually does not reach 10 nm, but the present invention forms the oxide film slightly thicker than the naturally formed oxide film. In order to form a stable chemical bond between the oxide and the resin which is stamped on it, at least Need to be 10nm. On the other hand, if an oxide film exceeding 100 nm is formed, damage will occur in the oxide film and the resin adhesion will be reduced. Therefore, the oxide film is controlled to 10 to 100 nm. By controlling in this range, excellent adhesiveness, such as resin adhesiveness, can be imparted. If the step or stability of the oxide film formation is considered, it is preferably 15-50 nm, and more preferably 20-40 nm.

(Measurement method of oxide film thickness)

1μm左右之光束直徑測量，測量於粗糙化層之各個凸部的氧化膜厚，藉此可測量排除了凹凸影響之氧化膜厚。此外亦可使用穿透式電子顯微鏡法直接觀察氧化膜厚。又，關於測量點數，確認任意5處之氧化膜厚，算出其平均值，藉此定義為粗糙化層的氧化膜厚。 In addition, the method for measuring the thickness of the oxide film of the present invention can be measured by the following method: using an Auje electronic energy spectrum analysis device, the acceleration voltage is measured at a low acceleration voltage of about 1 kV in the depth direction. Also, by taking the measurement area as

Measurement of the beam diameter of about 1 μm measures the oxide film thickness of each convex portion of the roughened layer, thereby measuring the oxide film thickness excluding the influence of unevenness. It is also possible to directly observe the thickness of the oxide film using a transmission electron microscope. Regarding the number of measurement points, the oxide film thickness at any of five points was confirmed, and the average value was calculated to define the oxide film thickness of the roughened layer.

(About types of roughening layer)

Furthermore, the roughened layer is preferably made of, 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. , Iridium, or an iridium alloy. The reason is that the oxide film composed of these components is relatively easy to control to 10 to 100 nm. In particular, from the viewpoint of improving the adhesion between the substrate and the upper film, a roughened layer made of copper, a copper alloy, nickel, or a nickel alloy is more preferred. Examples of the copper alloy include copper-tin alloy and copper-zinc alloy. Examples of the nickel alloy include nickel-zinc alloy and nickel-tin alloy.

(About the film thickness of the roughened layer)

The thickness of the roughened layer is not particularly limited. However, as the film thickness increases, the unevenness formed by roughening tends to become larger. Therefore, in order to increase the roughened shape, The coating thickness 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 coating thickness exceeds 3 μm, there is a concern that the roughened layer may fall off during transportation, that is, the so-called “falling powder” may increase. Therefore, the coating thickness of the roughened layer is preferably 3 μm or less, more preferably 2 μm or less, and even more preferably 1.5 μm or less.

(About the number of roughened layers)

In addition, the number of layers of the roughened layer is a single layer or a plurality of layers. When considering the complexity of the manufacturing steps and the like, it is preferably within 3 layers. Regarding the step of forming the roughened layer, if the roughened layer is formed by the so-called multiple roughening of the second roughened layer after the first roughened layer is formed, the specific surface area can be made with a relatively thin film thickness. Larger, so better. In addition, an intermediate layer (not shown) may be formed between the conductive substrate and the roughened layer before forming the roughened layer. For example, in order to improve the diffusion and / or adhesion of the substrate, copper, a copper alloy, nickel, a nickel alloy, cobalt, a cobalt alloy, or the like may be formed as an intermediate layer. If an oxide film is formed on the surface of these layers formed as an intermediate layer, it will peel off from the roughened layer of the upper layer. Therefore, it is different from the roughened layer surface in that an oxide film is not formed. Furthermore, when the roughened layer is formed in multiple layers, since the oxide film or specific surface area of the roughened layer formed on the outermost surface of the conductive substrate is important, the roughened layer will be formed on the outermost surface. The oxide film and specific surface area of the chemical layer are defined.

In addition, these coating thicknesses are not determined locally, but are measured at least with a collimator diameter of 0.2 mm or more by a fluorescent X-ray method (such as a film thickness measuring device such as SFT9400 (trade name) manufactured by SII Corporation). The average film thickness obtained at 3 points. When a plurality of roughened layers are formed, the total thickness of all layers is defined as the thickness of the roughened layer.

(About conductive substrate)

Moreover, as a component of the metal substrate (conductive substrate) to be used, copper, copper alloy, Iron, iron alloys, aluminum or aluminum alloys, etc. Among them, copper or copper alloys having good electrical conductivity are preferred.

For example, as an example of a copper alloy, the alloy "C14410 (Cu-0.15Sn" manufactured by Furukawa Electric Industry Co., Ltd., trade name: EFTEC (registered trademark) -3) published by the CDA (Copper Development Association) can be used. ) "," C19400 (Cu-Fe-based alloy material, Cu-2.3Fe-0.03P-0.15Zn) "," C18045 (Cu-0.3Cr-0.25Sn-0.5Zn, manufactured by Furukawa Electric Industry Co., Ltd., trade name : EFTEC-64T) "," C50710 (Cu-2.0Sn-0.2Ni-0.05P), manufactured by Furukawa Electric Co., Ltd., trade name: MF202 "," C70250 (Cu-3Ni-0.65Si-0.15Mg), Manufactured by Furukawa Electric Industry Co., Ltd., trade name: EFTEC-7025 ", etc. The unit of the number before each element is mass%. Since these copper alloy substrates have different electrical conductivity or strength, they are appropriately selected and used according to required characteristics. Among them, a copper alloy strip having a conductivity of 50% IACS or more is preferred.

As the iron or iron alloy, for example, 42 alloy (Fe-42mass% Ni), stainless steel, or the like can be used. Although these ferroalloy substrates are not very conductive, they can be applied to lead frames that do not require much electrical conductivity for the purpose of transmitting electrical signals.

As the aluminum or aluminum alloy, for example, A5052 can be used.

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

(Upper layer of roughening layer)

In addition, according to the present invention, in order to provide solder wettability and / or wire bonding property and grain bonding property of the lead frame to the upper layer (surface layer) of the roughened layer at the position where the semiconductor device is to be mounted, Single or multiple layers are formed on the entire surface or part of the lead frame material from palladium, palladium alloy, rhodium, rhodium alloy, ruthenium, ruthenium alloy, platinum, platinum alloy, iridium, iridium alloy, gold, gold alloy, silver or silver Close A film made of any one of gold. Among them, as a typical layer structure, Pd / Au, Rh / Au, Pd / Ag / Au, Pd / Rh / Au, and Ru / Pd / Au are sequentially coated from the roughened layer to the lateral surface. Wait. Although these coating thicknesses are not particularly limited, if they are too thick, they may bury the unevenness of the roughened layer and become unable to function, or the cost may increase due to the use of noble metals. Therefore, the total coating thickness of these upper layers is preferably 1 μm or less. As palladium alloy, rhodium alloy, ruthenium alloy, platinum alloy, iridium alloy, gold alloy or silver alloy, palladium alloy can be palladium-silver alloy, rhodium alloy can be rhodium-palladium alloy, ruthenium alloy can be ruthenium-iridium alloy, platinum The alloy can be platinum-gold alloy, the iridium alloy can be iridium-ruthenium alloy, the gold alloy can be gold-silver alloy, the silver alloy can be silver-tin alloy, and the like.

In addition, when other coating layers are formed on the roughened layer, peeling may occur if an oxide film is formed. Therefore, it is preferable to go through "in the state where the oxide film is not formed on the surface layer of the roughened layer. Forming its upper layer, and then forming an oxide film "to thereby form the oxide film, for example, preferably by immersing the upper layer in a chemical liquid having an oxidizing power and / or performing a heat treatment in the atmosphere under appropriate conditions. form.

(Coated part of roughened layer)

In addition, in the formation part of the roughened layer of the present invention, it may be formed on at least a part of the part to be subjected to the resin stamping, and of course, it may be processed on the entire surface, or the roughened layer may be partially formed. In addition, for example, it is preferable that at least 1/5 or more of the portion of the lead frame to be resin-molded is formed, and further preferably formed in an area of 1/2 or more, so that the effect of improving the adhesion can be exerted. It is best implemented on the entire surface of the resin mold. As the shape of the locally roughened layer, various shapes such as a stripe shape, a dot shape, and a ring shape can be adopted. In addition, a product having only one surface on the resin stamper may be formed on only one surface, for example.

(About formation method of roughening layer)

In addition, according to the present invention, although the method for forming the roughened layer is not particularly specified, it is relatively easy to control the roughened plating by current density or stirring, and it is simple. Therefore, it is preferable to use a plating method when forming the roughened layer. form. From the viewpoint of productivity, it is more preferably formed by wet plating.

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

FIG. 1 is a schematic cross-sectional view of a lead frame according to the present invention. A schematic view showing an oxide film having a coating thickness controlled to 10 to 100 nm is formed on the surface where the roughened layer is formed. It is important for this oxide film to be formed relatively uniformly on the surface, and its coating thickness is controlled to be 10 to 100 nm. In addition, the roughened layer has a specific surface area of 110% or more, and exhibits an optimal surface property in which both the alignment effect and the resin adhesion of the oxide film are optimal.

Fig. 2 is a schematic sectional view showing a specific surface area of the present invention. Although this cross-sectional view is a two-dimensional description, the value obtained by dividing the length of the topmost line segment (A) by the length of the topmost straight line (B) is the specific surface area, which can be measured using a non-contact interference microscope, for example. The specific surface area was obtained with A / B shown in the figure.

FIG. 3 is a schematic cross-sectional view as follows: This is an example of a different form of an example (embodiment) of the present invention. A first roughened layer (2-1) is formed on a conductive substrate (1), and further formed on the upper layer. There is a second roughened layer (2-2), and an oxide film (3) is formed on the surface of the second roughened layer at 10 to 100 nm. As described above, the roughened layer may be formed of a plurality of layers. For example, the roughened layer (2-1) of the first layer may be made of copper, and the roughened layer (2-2) of the second layer may be made of nickel. In addition, regarding the oxide film (3), the thickness of the oxide film of the roughened layer formed on the outermost layer is prescribed, and an oxide film may not be formed on the first layer in consideration of the possibility of peeling of the upper layer. Also, this second floor is a round It is also possible for the part to be formed. In this case, the part exposed on the surface layer must be oxidized. In addition, the portion where the roughened layer (2, 2-1, 2-2) and the oxide film (3) are to be formed may be formed on at least a part of a portion to be subjected to resin molding, and of course, it may be processed on the entire surface. A roughened layer may be formed locally. In addition, for example, it is preferable that at least 1/5 or more of the portion of the lead frame to be resin-molded is formed, and further preferably formed in an area of 1/2 or more, so that the effect of improving the adhesion can be exerted. As the shape of the locally roughened layer, various shapes such as a stripe shape, a dot shape, and a ring shape can be adopted. In addition, a product having only one surface on the resin stamper may be formed on only one surface, for example.

[Example]

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

Various conductive substrates shown in Table 1 prepared in advance with a test piece size of 40 mm × 40 mm and a thickness of 0.2 mm were prepared. After undergoing the pretreatment of the cathodic electrolytic degreasing and pickling steps shown below, the invention examples were obtained as " A roughened layer is formed to control the specific surface area and the thickness of the oxide film. " As comparative examples, those whose oxide film thickness is not controlled and those whose oxide film thickness is too thick, and those whose oxide film thickness is controlled but whose specific surface area is small are produced. In addition, as a method for controlling the thickness of the oxide film, the thickness of the oxide film is controlled by keeping it in the air at a temperature range of 25 ° C to 100 ° C for 5 seconds to 60 seconds. As the samples of each embodiment or comparative example, Examples 1 to 10, 13 to 20, 21 to 23 (though not shown in Examples 21 to 23, but also provided with an intermediate layer) and 24 to 27, And Comparative Examples 1 to 3, those illustrated in FIG. 1 were prepared. Regarding Examples 11 and 12, those illustrated in FIG. 3 were prepared. In addition, regarding Examples 28 and 29, the surface as shown in FIG. 3 was prepared, and the surface layer was partially followed by the order of Pd / Au or the order of Rh / Au. Orderly covered person.

(Pretreatment conditions)

[Cathode electrolytic degreasing]

Degreasing solution: NaOH 60g / L

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

[Pickling]

Pickling solution: 10% sulfuric acid

Pickling conditions: immersion for 30 seconds at room temperature

(Roughened plating conditions)

[Roughened Cu plating]

Plating solution: Copper sulfate: 5 ~ 10g / L based on copper concentration, sulfuric acid: 30 ~ 120g / L, ammonium molybdate: 0.1 ~ 5.0g / L based on Mo metal

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

[Roughened Ni plating]

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

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

[Roughened Pd plating]

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

Plating conditions: current density 8A / dm ² , temperature 60 ℃

[Roughened Cu-Sn plating]

Plating solution: CuCN 40g / L, Na ₂ O ₃ Sn 20g / L, NaCN 65g / L, NaOH 7.5g / L

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

(Usually intermediate plating conditions)

[Ni plating] (usually Ni plating)

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

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

[Co Plating [(Usually Co Plating)

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

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

[Cu plating] (usually Cu plating)

Plating solution: CuSO ₄ -5H ₂ O 250g / L, H ₂ SO ₄ 50g / L, NaCl 0.1g / L

Plating conditions: current density 6A / dm ² , temperature 40 ℃

(Normal Pd plating conditions)

[Pd plating]

Plating solution: Pd (NH ₃ ) ₂ Cl ₂ 45g / L, NH ₄ OH 90ml / L, (NH ₄ ) ₂ SO ₄ 50g / L, Parashiguma glossing agent (trade name, manufactured by Matsuda Industry Co., Ltd.) 10ml / L

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

(Au plating conditions)

[Au plating]

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

Plating conditions: current density 1A / dm ² , temperature 40 ℃

(Rh plating conditions)

[Rh plating]

Plating solution: RHODEX (trade name, manufactured by Japan Electroplating Engineering Co., Ltd.)

Plating conditions: current density 1.3A / dm ² , temperature 50 ℃

On each of the test pieces of each of the examples or comparative examples prepared as described above, a transfer mold test device (product name: Model FTS) manufactured by Hori Seiki Co., Ltd. was resin-molded to form a pudding-like test piece having a contact area of 4 mm ² . . Each test piece was put into a high-temperature and high-humidity test (holding it at 85 ° C. and 85% RH for 168 hours), and the test piece was subjected to adhesion evaluation and the like. The results are shown in Table 2.

(Evaluation of resin adhesion)

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

Evaluation conditions: Device: 4000Plus, made by Nordson Advanced Technology (trade name), load cell: 50kg

Measuring range: 10kg

Test speed: 100μm / s

Test height: 10μm

"A" (excellent) indicates an average of 10 kgf / mm ² or more, "B" (good) indicates an average of 5 kgf / mm ² or more and less than 10 kgf / mm ² , and "D" (bad) indicates an average It is a case of 0 kgf / mm ² or more and less than 5 kgf / mm ² .

The above-mentioned "resin adhesion evaluation" results correspond to both "initial shear strength" and "shear strength after environmental test". "Shear strength after environmental test" is the value after "holding for 168 hours in a high-temperature and high-humidity environment of 85 ° C and 85% environment after resin compression molding". The "initial shear strength" refers to "the shear strength immediately after preparation".

(Evaluation of powder fall)

Sensory evaluation was performed visually. "A" (excellent) indicates the case where powder fall is not confirmed, "B" (good) indicates the case where a small amount of powder fall is generated, "C" (may) indicates a case where a few powder fall is generated, and "D" (poor) It indicates that there is a lot of powder falling. A ~ C are practical grades. This dusting property evaluation is shown in Table 2 as "presence or absence of dusting".

According to the present invention, it can be seen that Comparative Example 1 in which the thickness of the oxide film is naturally formed and Invention Example in which the thickness of the oxide film is intentionally adjusted, the shear strength difference after the environmental test is very large. By further controlling the thickness of the oxide film, High resin adhesion. In addition, in Comparative Example 2 in which the oxide film thickness was too thick, it was found that the initial bonding strength was low. This is because peeling occurs inside the oxide film, and it is important to appropriately control the thickness of the oxide film. On the other hand, in Comparative Example 3, although the specific surface area is slightly smaller than the examples, it can be seen that if the specific surface area is not more than 110%, the shear strength after the environmental test will be lowered.

Therefore, it can be seen that by controlling both the specific surface area and the thickness of the oxide film on the surface layer, it shows very excellent resin adhesion before and after the environmental test, and by having a roughened layer having an appropriate specific surface area, It can also provide a lead frame with excellent powder fall.

Although the present invention is described together with its implementation, as long as it is not specifically specified, it is not intended to limit the present invention in any detail of the description, and should not violate the spirit of the invention shown in the scope of the attached patent application Explained extensively with the scope.

This application claims priority based on Japanese Patent Application No. 2016-079867, filed in Japan on April 12, 2016, which is hereby incorporated by reference and its contents are incorporated as part of the description of this specification.

1‧‧‧ conductive substrate

2‧‧‧ Roughened layer

3‧‧‧ oxide film

Claims (7)

A lead frame material has a roughened layer on a conductive substrate, the roughened layer is in a roughened state with a specific surface area of 110% or more, and has an oxide film provided on the outermost surface of the roughened layer. The thickness of the oxide film is Above 10 nm and below 100 nm. For example, the lead frame material of the first scope of the application for a patent, wherein the conductive substrate is copper, copper alloy, iron, iron alloy, aluminum or aluminum alloy. For example, the lead frame material of the first or second scope of the patent application, wherein the roughened layer is made of copper, copper alloy, nickel, nickel alloy, palladium, palladium alloy, silver, silver alloy, tin, tin alloy, zinc, zinc Any of alloy, rhodium, rhodium alloy, ruthenium, ruthenium alloy, iridium, or iridium alloy. For example, the lead frame material according to any one of claims 1 to 3, wherein the roughened layer is a single layer or multiple layers. For example, the lead frame material according to any one of claims 1 to 4, wherein the conductive substrate has a roughened layer, and a single layer or a plurality of layers made of palladium, palladium alloy, A surface layer made of any of rhodium, a rhodium alloy, ruthenium, a ruthenium alloy, platinum, a platinum alloy, iridium, an iridium alloy, gold, a gold alloy, silver, or a silver alloy serves as an upper layer of the roughened layer. A method for manufacturing a lead frame material according to any one of claims 1 to 5, wherein the roughened layer is formed by electroplating. A semiconductor package using a lead frame material according to any one of claims 1 to 5 of the scope of patent application.