WO2021039086A1

WO2021039086A1 - Metallic plate, metal-resin composite, semiconductor device, and metallic plate production method

Info

Publication number: WO2021039086A1
Application number: PCT/JP2020/025055
Authority: WO
Inventors: 慎青柳; 俊紘笹田
Original assignee: Ｊｘ金属株式会社
Priority date: 2019-08-29
Filing date: 2020-06-25
Publication date: 2021-03-04
Also published as: JP2021034705A; TW202123410A

Abstract

This metallic plate 1 has a resin-covered surface covered with a resin member, wherein the metallic plate 1 has at least three recesses 2 that are formed side by side on the resin-covered surface so as to sink into the resin-covered surface, at least three of the recesses 2 lined up in a recess-array direction Da are arranged apart from each other on the resin-covered surface at multiple types of pitches P1, P2 of different distances.

Description

Manufacturing method of metal plate, metal resin composite, semiconductor device, and metal plate

This specification discloses a technique relating to a metal plate, a metal resin composite, a semiconductor device, and a method for manufacturing the metal plate.

Improving the adhesion between metal and resin is required in various fields and applications, and the development of related technologies is widely carried out.

As an example of this type of technology, Patent Document 1 proposes a method for improving the adhesion between a lead frame on which a semiconductor chip is mounted and a resin that seals the lead frame and the semiconductor chip in a semiconductor device. ing.
More specifically, Patent Document 1 describes "mounting and sealing a semiconductor chip" for the purpose of "providing a lead frame having higher adhesion to a sealing resin and further improving reliability" and the like. A lead frame used in a semiconductor device sealed with a resin, wherein an uneven portion is formed on the surface of a portion of the lead frame sealed with the sealing resin, and the uneven portion is in the depth direction of the concave portion. It discloses a "lead frame" in which a key portion extending in an intersecting direction is formed.

In Patent Document 1, as a specific method for forming a "key portion", "as shown in FIG. 6, the processing punch 20 used for the first two punching processes is defined on the surface. A plurality of protrusions 20a are formed with a pitch of. First, in the first stage A, a punching process is performed under a predetermined relative positional relationship of the processing punch 20 with respect to the lead frame 5, and the lead frame 5 is formed. A recess 5a corresponding to the protrusion 20a is formed on the surface of the lead frame 5. When the punching process in the stage A is completed, the lead frame 5 is conveyed to the next stage B. ”,“ In the stage B, FIG. As shown, the second punching process is performed on the lead frame 5 under the positional relationship in which the pitch P of the protrusions is shifted by half the pitch with respect to the relative positional relationship of the processing punch 20 with respect to the lead frame 5 in the stage A. The recess 5a is formed at a position different from the position of the recess 5a formed in the stage A. ”,“ When the punching process in the stage B is completed, the lead frame 5 is conveyed to the next stage C. In the stage C, the surface of the lead frame 5 is punched by a machined punch 21 having a flat surface, so that the convex portion 5b located between the plurality of concave portions 5a formed on the surface of the lead frame 5 is formed. The tip portion is crushed to form the key portion 5c. "

JP-A-2007-258587

In the technique described in Patent Document 1, only "recesses" of the number and density corresponding to the "protrusions" of the "machining punch" are formed in the "lead frame". Then, for a technique of finely processing the convex portion while ensuring the required strength of the convex portion of the "machining punch" for providing the "recess", or for other reasons, the "protrusion" that can be provided on the "machining punch" can be provided. There is a limit to the number and density of "". Therefore, in the technique of Patent Document 1, it is difficult to further shorten the distance between a plurality of "recesses" that can be formed in the "lead frame", that is, to form the "recesses" more densely. .. As a result, the adhesion between the "lead frame" and the "sealing resin" cannot be sufficiently improved.

Further, in Patent Document 1, the formation of the "key portion" makes it difficult for the resin to enter the "recess", and a relatively large amount of air is provided between the "lead frame" and the "sealing resin". May be enclosed. When a large amount of air is sealed, the air expands, especially in a high temperature environment, and the sealing resin and the lead frame are separated from each other, which may cause inconveniences such as deterioration of adhesion.

This specification discloses a metal plate, a metal resin composite, a semiconductor device, and a method for manufacturing the metal plate, which can effectively enhance the adhesion between the metal plate and the resin member.

One metal plate disclosed in this specification has a resin-coated surface covered with a resin member, and has three or more recesses formed side by side on the resin-coated surface and recessed from the resin-coated surface. The recesses arranged in the recess arrangement direction are arranged apart from each other at a plurality of types of pitches having different distances on the resin-coated surface.

The other metal plate disclosed in this specification has a resin-coated surface covered with a resin member, and has a plurality of recesses formed side by side on the resin-coated surface and recessed from the resin-coated surface. The average value of the pitches of the recesses arranged in the recess arrangement direction on the resin-coated surface is less than 200 μm.

The metal-resin composite disclosed in this specification includes any of the above-mentioned metal plates and a resin member arranged so as to cover the resin-coated surface of the metal plate.

The semiconductor device disclosed in this specification includes the above-mentioned metal-resin composite and a semiconductor chip mounted on the lead frame of the metal-resin composite.

The method for manufacturing a metal plate disclosed in this specification is a method for manufacturing a metal plate by performing a press working by pressing a punch against a plate-shaped metal material, and one or a plurality of convex portions are provided side by side on the tip surface. A first press step of forming a first recess group including one or a plurality of recesses on the surface to be processed of the plate-shaped metal material by a punch, and a plurality or one convex portion are provided side by side on the tip surface. A second recess group including a plurality or one recess is formed on the surface to be machined by using a punch, at least partially overlapping the formation area of the first recess group, and the second recess group is formed. It includes a second pressing step in which each recess is provided so as to be separated from each recess of the first recess group.

According to the metal plate, the metal resin composite, the semiconductor device, and the method for manufacturing the metal plate described above, the adhesion between the metal plate and the resin member can be effectively improved.

It is a top view which shows typically the metal plate of one Embodiment. It is a top view which shows an example of the method of manufacturing the metal plate of FIG. It is a perspective view which shows an example of the punch which can be used in the manufacturing method of FIG. It is a top view which shows typically the metal plate of another embodiment. It is a partial cross-sectional view along the VV line of FIG. It is a partial cross-sectional view which shows the metal plate of FIG. FIG. 5 is an enlarged cross-sectional view showing one of the recesses provided on the surface of the metal plate of FIG. It is an enlarged cross-sectional view which shows the modification of the concave part. It is a top view which shows the metal plate of still another embodiment schematically. It is sectional drawing which shows typically the roughened surface of the resin coated surface. It is a vertical cross-sectional view and a plan view which show the specimen made using the metal plate in an Example.

The embodiments disclosed in this specification will be described in detail with reference to the drawings below.
The metal plate 1 illustrated in FIG. 1 has a plurality of recesses 2 formed side by side on the surface Sf and recessed from the surface Sf. The metal plate 1 may be made of, for example, a material containing copper, aluminum, or iron.

As will be described later, this surface Sf is a metal-resin composite provided with the metal plate 1 and is covered with a resin member, and corresponds to a resin-coated surface. In the illustrated example, substantially the entire surface Sf is a resin-coated surface covered with a resin member, but at least a part of the surface is covered with resin, and a plurality of resin-coated surfaces are covered with at least a part of the surface. Any one provided with a recess may be used. That is, the resin-coated surface may be present on at least a part of the surface of the metal plate.

Here, the plurality of recesses 2 are formed side by side in the recess arrangement direction Da (left-right direction in FIG. 1) on the resin-coated surface. The recesses 2 arranged in the recess arrangement direction Da are arranged apart from each other at a plurality of types of pitches P1 and P2 having different distances. In other words, the plurality of recesses 2 are formed so as to be located at non-uniform pitches P1 and P2 in the recess arrangement direction Da.

Such a metal plate 1 can be manufactured, for example, as shown in FIG.
First, a plurality of punches 61 as illustrated in FIG. 3 are used on the surface to be processed Sp of the plate-shaped metal material 51 such as a flat plate, as shown by a broken line in FIG. 2A. The first pressing step of forming the first recess group Gc1 including the recess 2 is performed. By the first pressing step, a semi-processed product 51a as shown in FIG. 2B is obtained. The recess 2 can be recessed so as not to penetrate the plate-shaped metal material 51.

The punch 61 is provided side by side with a main body 62 arranged so as to extend in a direction orthogonal to the work surface Sp of the plate-shaped metal material 51 and a tip surface 62a of the main body 62 close to the work surface Sp. It has a plurality of convex portions 63. The plurality of convex portions 63 are formed side by side at equal intervals in a predetermined direction in a plane on the tip surface 62a and in a direction orthogonal to the predetermined direction. In this example, on the tip surface 62a, there are a large number of substantially quadrangular pyramid-shaped convex portions 63 that taper toward the tip side, which is the side close to the work surface Sp. However, the shape and number of the convex portions 63 can be changed as appropriate.

In the first pressing step, the punch 61 is pressed against the work surface Sp of the plate-shaped metal material 51 and pressed, so that the work surface Sp is formed on the convex portion 63 provided on the tip surface 62a of the punch 61. The recesses 2 of the first recess group Gc1 having the corresponding shape, position and number are formed. More specifically, in this example, the concave portion 2 has 4 rows and 4 columns on the machined surface Sp of the semi-processed product 51a, substantially similar to the arrangement mode of the convex portion 63 of the tip surface 62a of the punch 61. A total of 16 pieces are formed.

Next, in the second pressing step, a second recess group Gc2 including a plurality of recesses 2 is further formed on the work surface Sp of the semi-processed product 51a as shown by a broken line in FIG. 2 (b). In the second pressing step, the same punch 61 used in the first pressing step can be used, but it is different from the first pressing step if the punch is provided with a plurality of or one convex portion arranged side by side on the tip surface. It may be used as a punch. Here, a case where a punch 61 having a tip surface having the same shape as that of the first press step is used in the second press step will be described. However, depending on the embodiment, it is possible to use a punch having a tip surface having a shape different from that of the first pressing process.

In this embodiment, in the second pressing step, the punch 61 is slightly shifted to one side in a predetermined direction (right side in the left-right direction in FIG. 2) from the pressing position in the first pressing step on the surface to be processed Sp. As can be seen from FIG. 2B, the second recess group Gc2 including the plurality of recesses 2 is formed in at least a part of the formation region of the first recess group Gc1 by pressing and pressing against the position. It is formed by overlapping. The direction in which the punch 61 is shifted coincides with the recessed arrangement direction Da described above.

However, here, each recess 2 of the second recess group Gc2 is set to each recess 2 of the first recess group Gc1 so that each recess 2 of the second recess group Gc2 does not overlap with each recess 2 of the first recess group Gc1. Positioned at a predetermined distance from 2. In the illustrated example, the second recess group Gc2 is arranged so that each recess 2 of the second recess group Gc2 is arranged between the adjacent recesses 2 of the first recess group Gc1 in the left-right direction of FIG. The recess 2 is formed.

Although not shown, it is also conceivable to further perform a third pressing step or the like on the surface to be machined by shifting the punch in a predetermined direction and pressing the punch to form a third recess group including a plurality of recesses. Be done. The pressing process is not limited to the first pressing process and the second pressing process, and can be performed three or more times.

As a result, as shown in FIG. 2C, the recess 2 of the first recess group Gc1 and the recess 2 of the second recess group Gc2 are formed on the surface to be processed which becomes the surface Sf as the resin coating surface. It is possible to manufacture the metal plates 1 formed by alternately arranging the punches 61 in the direction shifted (the left-right direction in FIG. 2) in the pressing process. In such a metal plate 1, the recesses 2 are formed more densely than when the recesses are formed by only one press, so that the resin enters each of the densely packed recesses 2. , The anchor effect of the resin due to the recess 2 is improved. As a result, excellent adhesion to the resin member can be exhibited.
If the adhesion between the metal plate and the resin member is low, outside air (air) containing moisture may pass between the metal plate and the resin member in a semiconductor device using the metal plate as a lead frame. In this case, if the semiconductor element mounted on the lead frame and generating heat during use comes into contact with the outside air (air) containing such moisture, there is a problem that malfunction occurs. On the other hand, since the metal plate 1 of this embodiment has excellent adhesion to the resin member, the occurrence of such a problem can be effectively suppressed.

It seems that by increasing the number of convex portions provided on the tip surface of the punch used for the press, the concave portions can be formed densely by one press, but if the convex portions are increased to some extent on the tip surface, It becomes difficult to secure the punch strength enough to withstand the press. Therefore, the adhesion of the metal plate to the resin member cannot be sufficiently improved by changing the shape of the tip surface of the punch.

Further, since the recesses 2 are densely packed, the outer surface between the recesses 2 has a shape that rises outward due to the meat flow of the metal material constituting the metal plate 1 at the time of pressing. In this case, since the anchor effect is higher than that when the outer surface is flat, the adhesion between the metal plate 1 and the resin member is further improved.

Although not shown, if one recess is formed on the work surface of the plate-shaped metal material by using a punch having one convex portion on the tip surface in the first pressing step, the tip is formed in the second pressing step. By punching a plurality of convex portions on the surface, a plurality of concave portions can be formed on both sides of the surface to be machined with the recesses interposed therebetween. Alternatively, when a plurality of recesses are formed on the surface to be processed of the plate-shaped metal material by using a punch having a plurality of convex portions on the tip surface in the first pressing step, the tip surface is formed in the second pressing step. A single recess may be formed between a plurality of recesses on the surface to be machined by a punch provided with one convex portion. As a result, three or more recesses are formed on the resin-coated surface of the metal plate 1.

When the first press step and the second press step of shifting and pressing the punch 61 as described above are performed, in the second press step, the adjacent recesses 2 of the first recess group Gc1 formed in the first press step 2 It is practically impossible to position and form the recess 2 of the second recess group Gc2 without any difference in the central position between the two. As a result, in the manufactured metal plate 1, there are inevitably a plurality of types of pitches P1 and P2 of the recesses 2 arranged in the recess arrangement direction Da. In other words, if the pitches P1 and P2 of the recesses 2 arranged in the recess arrangement direction Da of the metal plate 1 are not uniform, the metal plate 1 is manufactured by a method including a first press step and a second press step. It can be inferred. It is considered that such a plurality of types of pitches P1 and P2 are caused by the clearance of the positioning pin of the punch 61 and the elongation of the material by the punch 61. The difference between the pitch P1 and the pitch P2 is preferably 1 μm to 40 μm, and may be, for example, about 10 μm on average.

The pitches P1 and P2 referred to here are cycles in which the recesses 2 are arranged in the recess arrangement direction Da, and specifically, the recesses 2 and the recesses 2 are arranged in the width Wc of the opening of the recesses 2 along the recess arrangement direction Da. It is the total length of the separation distances D1 or D2 between the recesses 2 adjacent to any one side of the recess arrangement direction Da. Further, the recess arrangement direction Da means any direction in which a plurality of recesses 2 are lined up on the resin coating surface (for example, the left-right direction, the vertical direction, etc. in FIG. 1), and at least one of those directions. In the direction, the recesses 2 may be arranged side by side with a plurality of types of pitches P1 and P2. In the embodiment illustrated in FIG. 1, as shown by an arrow in FIG. 1, the left-right direction corresponds to the recess arrangement direction Da. When viewed in the vertical direction of FIG. 1, the recesses 2 are arranged at a uniform pitch, and here, the vertical direction of FIG. 1 is not regarded as the recess arrangement direction.

A plurality of types of pitches P1 and P2 of the recesses 2 arranged in the recess arrangement direction Da may be sequentially repeated in the recess arrangement direction Da. In the embodiment shown in FIG. 1, two types of pitches P1 and P2 are sequentially, that is, alternately repeated in the recess arrangement direction Da. In another embodiment shown in FIG. 4, the recess 12 is formed so that the three types of pitches P1, P2, and P3 are sequentially repeated in the recess arrangement direction Da. The metal plate 11 in which the recesses 12 are formed at three or more types of pitches P1 to P3 that are sequentially repeated in the recess arrangement direction Da is manufactured, for example, by further performing a third pressing step at the time of manufacturing the metal plate 11. can do. Although not shown, a metal plate in which recesses are formed at four or more pitches that are sequentially repeated in the recess arrangement direction is also possible.

Specifically, the average value of the pitches P1 and P2 in the recess arrangement direction Da is preferably in the range of 50 μm to 200 μm. It is even more preferable that the average values of the pitches P1 and P2 are in the range of 50 μm to 120 μm. If the average values of the pitches P1 and P2 are too small, the inner surface of the recess 2 may become small. In this case, there is a concern that the contact area between the resin-coated surface including the recess 2 and the resin will decrease, resulting in inferior adhesion.

The average value of the separation distances D1 and D2 between the recesses 2 adjacent to the recess arrangement direction Da is preferably less than 80 μm, and even more preferably 70 μm or less, particularly less than 50 μm. In the manufacturing method described above, among the recess 2 of the first recess group Gc1 and the recess 2 of the second recess group Gc2, the average value of the separation distances between the recesses 2 adjacent to each other is less than 80 μm. It is preferable to perform one pressing step, a second pressing step, and the like. Particularly preferably, all of the separation distances are made shorter than the above upper limit values.
In this case, since the recesses 2 are sufficiently densely arranged on the resin-coated surface, good adhesion between the metal plate 1 and the resin member can be realized by improving the anchor effect. The separation distances D1 and D2 are located in the recess arrangement direction Da, at the end points of one recess 2 adjacent to each other on the other recess 2 side and on the onemost recess 2 side of the other recess 2. Measured as the distance to the located endpoint. Such short separation distances D1 and D2 between the recesses 2 can also be realized by the above-mentioned two or more presses. The separation distances D1 and D2 between the recesses 2 adjacent to the recess arrangement direction Da may be, for example, 1 μm or more, typically 20 μm or more.

As shown in the cross-sectional view of FIG. 5, the metal plate 1 can have a plurality of recesses 2 formed not only on the front surface Sf but also on the back surface Sb located on the back side of the front surface Sf. The pitch and separation distance of the recesses 2 can be set on the back surface Sb side as well as on the front surface Sf side as described above. In this case, the back surface Sb is also a resin-coated surface.
However, as can be seen from FIG. 5, the recess 2 on the front surface Sf and the recess 2 on the back surface Sb are orthogonal to the thickness direction of the metal plate 1 (vertical direction in FIG. 5) (horizontal direction in FIG. 5). ) Is preferably located. In other words, when the recess 2 on the front surface Sf and the recess 2 on the back surface Sb are not displaced in the direction orthogonal to the thickness direction of the metal plate 1 and are provided at the same position, they are locally located on the metal plate 1. Due to the fact that a portion having a thin thickness can be formed, the amount of deformation of the entire meat flow during pressing during the production of the metal plate 1 increases, and there is a concern that the mechanical strength and dimensional accuracy may decrease. Here, at least, the central position Cp in the width direction (horizontal direction in FIG. 5) of the recess 2 may not match between the one on the front surface Sf side and the one on the back surface Sb side.

In the metal plate 1 shown in FIG. 5, as shown in FIG. 6, the

resin members

3a and 3b are covered with the

resin members

3a and 3b so that the front surface Sf and the back surface Sb each become a resin-coated surface and are covered with the

resin members

3a and 3b. Arranged to form a metal resin composite 71. In the metal-resin composite 71, the resin of the

resin members

3a and 3b enters the recesses 2 of the front surface Sf and the back surface Sb, respectively, so that the metal plate 1 and the

resin members

3a and 3b have excellent adhesion. It will be demonstrated. Such arrangement of the

resin members

3a and 3b on the front surface Sf and the back surface Sb can be performed by, for example, insert molding or the like.
The metal-resin composite 71 shown is a metal plate 1 in which recesses 2 are formed in each of the front surface Sf and the back surface Sb, and

resin members

3a and 3b arranged so as to cover each of the front surface Sf and the back surface Sb of the metal plate 1. Although not shown, a recess may be formed only on the surface Sf, and / or a resin member may be arranged only on the surface Sf. The terms "front surface" and "back surface" used herein are merely used to distinguish one surface of the metal plate 1 from the other surface on the back side thereof, and the "back surface" and the "front surface" are used. It is also possible to replace and interpret.

In the above-described embodiment, the recess 2 provided on the resin-coated surface of the metal plate 1 is connected to the opening 2a that opens outward from the resin-coated surface to form the recess 2, as shown in the enlarged view of FIG. Has an inner surface to partition. The inner surface is formed by a flat bottom surface 2b located at the deepest part of the recess 2 and a side surface 2c connecting the opening 2a and the bottom surface 2b.
In the recess 2 having such a flat bottom surface 2b, it is preferable that the bottom surface 2b has an area of 20% to 60% with respect to the area of the opening 2a. If the area of the bottom surface 2b of the recess 2 is less than 20% of the area of the opening 2a, the inner surface of the recess 2 becomes too tapered as the inner surface becomes deeper, so that it becomes difficult for the resin to enter the vicinity of the bottom surface 2b. A large air layer may be formed. On the other hand, when the area of the bottom surface 2b of the recess 2 exceeds 60% of the area of the opening 2a, the corner portion of the portion where the bottom surface 2b and the side surface 2c intersect becomes sharp, and it becomes difficult for the resin to enter there, which is relatively difficult. There is concern that a large air layer will be formed. It is even more preferable that the area of the bottom surface 2b is 40% to 60% of the area of the opening 2a.

As shown in FIG. 7, it is preferable that the side surface 2c, which is substantially linear in cross-sectional view, is inclined at an angle θ within the range of 2 ° to 10 ° with respect to the perpendicular line standing on the bottom surface 2b. If this inclination angle θ is too large, there is a concern that the anchor effect cannot be sufficiently obtained. If the inclination angle θ is small, when the recess 2 is formed by the punch 61, the punch 61 may not easily come out of the recess 2.

Alternatively, as in the modified example shown in FIG. 8, the recess 22 having a curved inner surface from the side surface 22c to the bottom surface 22b can be formed. The inner surface of the recess 22 shown in FIG. 8 has a curved surface shape from the opening 22a through the side surface 22c to the bottom surface 22b, and further, the curved surface shape is an arc shape in a cross-sectional view. The inner surface of the recess 22 has a spherical crown shape, which is the shape of a portion of the spherical surface cut out by a plane intersecting the spherical surface.
The recess 22 having such a curved inner surface is also suitable from the viewpoint of suppressing the formation of an air layer because the resin is easily filled over the entire recess 22.

The width Wc of the opening 2a of the recess 2 along the recess arrangement direction Da is preferably 10 μm to 500 μm, more preferably 20 μm to 90 μm. If the width Wc of the opening 2a of the recess 2 is too wide, the number density of the recesses becomes small, and the effect of improving the adhesion may not be sufficiently obtained. On the other hand, if the width Wc of the opening 2a of the recess 2 is too narrow, it becomes difficult for the resin to enter the recess 2, and there is a concern that an air layer may be formed in the recess 2.

The depth Dc of the recess 2 is preferably 5 μm to 50 μm, and even more preferably 15 μm to 45 μm. The depth Dc of the recess 2 means the maximum depth measured from the opening 2a to the bottom surface 2b along the thickness direction of the metal plate 1. If the recess 2 is too deep, it becomes difficult for the resin to sufficiently penetrate into the deep portion, and an air layer may be formed. If the recess is too shallow, it is undeniable that the improvement of adhesion may be insufficient.
Further, the depth Dc of the recess 2 is preferably 5% to 35%, particularly 7% to 30% with respect to the thickness T (plate thickness) of the metal plate. The ratio of the depth Dc of the recess 2 to the thickness T of the metal plate is preferably 5% or more from the viewpoint of improving the adhesion, but if it exceeds 35%, the strength of the metal plate 1 may decrease. I am concerned.

The number density of the recesses 2 on the resin-coated surface ^{is preferably 120 pieces / mm 2} to 280 pieces / mm ² , and more preferably 180 pieces / mm ² to 280 pieces / mm ² . Thereby, the adhesion with the resin member can be effectively improved. The higher the number density, the more preferable, but it is often below the above upper limit. The number density is obtained by counting the number of recesses 2 existing per unit area (1 mm × 1 mm) of the resin-coated surface.

The planar shape of the opening 2a of the recess 2 can be various shapes, and among them, a circular shape (not shown), a quadrangle such as a square or a rectangle as shown in the figure, or another polygonal shape can be used. In this case, many recesses 2 can be provided densely. In particular, the concave portion 2 having a square shape such as a square in a plan view is preferable because the convex portion 63 of the punch 61 for forming the concave portion 2 can be easily formed into a corresponding shape by scraping with a grindstone or the like.

In the above-described embodiment, the resin-coated surface is formed with a rhombic-shaped recess 2 in which the recesses 2 adjacent to each other are located so that their corners face each other. In other words, each of these square-shaped recesses 2 is arranged so that each side thereof is inclined at approximately 45 ° with respect to the recess arrangement direction Da. On the other hand, as in the

metal plates

31 and 41 of the other embodiments shown in FIGS. 9A and 9B,

square recesses

32 and 42 are formed on the resin-coated surface of the

recesses

32 and 42 adjacent to each other. It is also possible to form the sides so that they are parallel to each other.
However, since the corners of the diamond-shaped recesses 2 are adjacent to each other and are located so as to face each other, the separation distance between the adjacent recesses 2 becomes short, and it becomes difficult for air to pass between them. It is preferable because it is difficult for air to reach the inside.

The metal plate 31 shown in FIG. 9A has almost the same configuration as the metal plate 1 shown in FIG. 1 except that the orientation of each recess 32 is rotated by 45 ° around its center of gravity in a plan view. To have.
The metal plate 41 shown in FIG. 9B is different from the metal plate 31 shown in FIG. 9A only in that the recesses 42 are arranged in a staggered pattern in the recess arrangement direction Da. The arrangement mode of the recesses is not limited to those arranged linearly in the recess arrangement direction.

By the way, among the resin-coated surfaces of the metal plate 1, at least the outer surface Se located between the recesses 2, preferably, as shown in FIG. 10, the entire resin-coated surface including the outer surface Se and the inner surface of the recess 2 is It is preferably a roughened surface.
As described above, when the separation distances D1 and D2 between the recesses 2 are shortened in order to densely distribute the recesses 2, the outer surface Se between the recesses 2 is not clear from the drawing due to the meat flow during pressing. , It becomes a swelling shape. Then, as shown in FIG. 10, the calculated average roughness Ra of such a raised outer surface Se is set to 0.3 μm or more, and the maximum height Rz of the outer surface Se is set to 2.0 μm or more, whereby the rough outer surface Se is set. Increases the resin anchoring effect. Therefore, the adhesion between the metal plate 1 and the resin member can be further improved. The calculated average roughness Ra and the maximum height Rz referred to here are based on JIS B0601. It is preferable that the outer surface Se or the like of the resin-coated surface is roughened to obtain a roughened surface. The roughened surface can be confirmed by a stereomicroscope or SEM. If the roughening treatment is not applied, the surface becomes glossy, and if the roughening treatment is performed, the surface becomes non-glossy, so that it can be visually identified.

In the above description, the preferred configuration or embodiment has been described with the metal plate 1 of the embodiment shown in FIG. 1 as a representative example, but at least one of those configurations or embodiments is the metal plate 11 of another embodiment. , 31 and 41 can also be applied.

The metal plates such as the

metal plates

1, 11, 31 and 41 described above can be used for various purposes in which the resin member is arranged on the resin coating surface thereof, and among them, the semiconductor device. Especially suitable for use in.

In semiconductor device applications, the metal plate can be a lead frame on which a semiconductor chip is mounted. Some lead frames have, for example, a die pad on which a semiconductor chip is arranged and a lead such as an inner lead or an outer lead around the die pad. The resin-coated surface of the metal plate can be a surface of the die pad facing the semiconductor chip side.
When the metal plate is used as a lead frame, the semiconductor device includes a metal-resin composite in which a resin member is arranged so as to cover the resin-coated surface of the metal plate, and a semiconductor chip mounted on the lead frame. can do.

Alternatively, since the above metal plate has high adhesion to the resin member, it is also suitable to be used for, for example, a waterproof connector or an insert part such as a camera part or a smartphone part that requires waterproofness.

Below, the metal plate as described above was prototyped and its performance was confirmed, so it will be explained below. However, the description here is for the purpose of mere illustration, and is not intended to be limited thereto.

The plate-shaped metal material was pressed twice by shifting the pressing position by the punch to prepare a metal plate as shown in FIG. Table 1 shows various dimensions and other conditions of the metal plates of Examples 1 to 12 and Comparative Examples 1 and 2. In Comparative Example 1, no pressing was performed, and a metal plate having no recesses on the resin-coated surface was used. Further, in Comparative Example 2, a recess was formed by pressing only once. In Table 1, the average pitch means the average value of the pitch P1 and the pitch P2, and the average separation distance of the recess means the average value of the separation distance D1 and the separation distance D2.

For each of the metal plates of Examples 1 to 12 and Comparative Examples 1 and 2, a resin member is formed on the resin-coated surface by insert molding, and the metal plate 51 and the resin member having a cavity in the center as shown in FIG. A metal resin composite 71a composed of 3c and 3d was obtained. Further, as shown in FIG. 11, the cavity of the metal-resin composite 71a was closed from both sides with

lids

81a and 81b via an adhesive 81c to prepare a specimen 91 simulating a semiconductor device. However, the specimen 91 does not have a semiconductor chip in the internal cavity. The

resin members

3c and 3d and the

lids

81a and 81b were made of a liquid crystal polymer (M-350B of Zider (registered trademark) manufactured by JX Liquid Liquid Co., Ltd.). As the adhesive 81c, EP330 manufactured by Cemedine Co., Ltd. was used.

Each of these specimens 91 was subjected to a heat cycle test, and after the test, the specimen 91 was submerged in water to check for air leakage. The results are also shown in Table 1. In the heat cycle test, the temperature was repeatedly raised and lowered from −65 ° C. to 160 ° C.
In Table 1, “⊚” for the adhesion force indicates that there was no air leakage after the heat cycle test was performed 500 times. “○” indicates that there was no air leakage after the heat cycle test was performed 100 times. “X” indicates that there was an air leak after the heat cycle test was performed 50 times. “Δ” indicates that after performing the heat cycle test 50 times, the covered complex was submerged in water and there was no air leakage.

In each of Examples 1 to 12, the difference in pitch between the recesses was 1 μm to 40 μm.
From Table 1, in Examples 1 to 12, the adhesion to the resin member is enhanced and the adhesion is increased due to the fact that the recesses having a relatively short average separation distance are densely formed on the resin-coated surface. The result was that it was good. On the other hand, in Comparative Example 1, no recess was formed on the resin-coated surface, and in Comparative Example 2, the average separation distance between the recesses was long, resulting in low adhesion.
Therefore, it was found that the adhesion between the metal plate and the resin member can be effectively improved.

1, 11, 31, 41, 51

Metal plate

2, 12, 22, 32, 42

Recess

2a,

22a Opening

2b,

22b Bottom surface

2c,

22c Side surface

3a, 3b, 3c, 3d Resin member 51 Plate metal material 51a Half Processed product 61 Punch 62 Main body 62a Tip surface 63

Convex

71, 71a Metal resin composite 81a, 81b Lid 81c Adhesive 91 Specimen Da Recess arrangement direction Sf Front surface Sb Back surface Sp Processed surface P1, P2, P3 Recess arrangement Pitch of recesses lined up in the direction D1, D2 Separation distance between recesses adjacent to the recess arrangement direction Wc Width of the recess opening along the recess arrangement direction Dc Recess depth Cp Center position in the width direction of the recess Gc1 First recess group Gc2 Second recess group T Thickness of metal plate Se Outer surface between recesses

Claims

A metal plate having a resin-coated surface covered with a resin member.
It has three or more recesses formed side by side on the resin-coated surface and recessed from the resin-coated surface.
A metal plate in which the recesses arranged in the recess arrangement direction on the resin-coated surface are arranged apart from each other at a plurality of types of pitches having different distances.
The metal plate according to claim 1, wherein the recesses are formed so that the plurality of types of pitches of the recesses arranged in the recess arrangement direction are sequentially repeated in the recess arrangement direction.
The metal plate according to claim 2, wherein the pitches are of two types, and the two types of pitches are alternately repeated in the concave arrangement direction.
The metal plate according to any one of claims 1 to 3, wherein the average value of the pitches is less than 200 μm.
A metal plate having a resin-coated surface covered with a resin member.
It has a plurality of recesses formed side by side on the resin-coated surface and recessed from the resin-coated surface.
A metal plate having an average pitch of the recesses arranged in the recess arrangement direction on the resin-coated surface of less than 200 μm.
The metal plate according to any one of claims 1 to 5, wherein the inner surface of the recess includes a flat bottom surface having an area of 20% to 60% with respect to the area of the opening of the recess.
The metal plate according to any one of claims 1 to 5, wherein the inner surface of the recess has a curved surface from the side surface to the bottom surface.
Any one of claims 1 to 7 in which at least the calculated average roughness Ra of the outer surface located between the recesses of the resin-coated surface is 0.3 μm or more and the maximum height Rz is 2.0 μm or more. The metal plate described in the section.
The metal plate according to any one of claims 1 to 8, wherein the width of the opening of the recess along the recess arrangement direction is 10 μm to 500 μm.
The metal plate according to any one of claims 1 to 9, wherein the number density of the recesses on the resin-coated surface is 120 pieces / mm 2 to 280 pieces / mm 2.
The metal plate according to any one of claims 1 to 10, wherein the depth of the recess is 5 μm to 50 μm.
The metal plate according to any one of claims 1 to 11, wherein the depth of the recess is 5% to 35% with respect to the thickness of the metal plate.
The metal plate according to any one of claims 1 to 12, wherein the planar shape of the opening of the recess is circular or polygonal.
The resin-coated surface includes a front surface and a back surface located on the back side of the surface.
The metal plate according to any one of claims 1 to 13, wherein the recess on the front surface and the recess on the back surface are located so as to be displaced in a direction orthogonal to the thickness direction of the metal plate.
A metal-resin composite comprising the metal plate according to any one of claims 1 to 14 and a resin member arranged so as to cover the resin-coated surface of the metal plate.
The metal-resin composite according to claim 15, wherein the metal plate is a lead frame on which a semiconductor chip is mounted.
A semiconductor device including the metal-resin composite according to claim 16 and a semiconductor chip mounted on the lead frame of the metal-resin composite.
It is a method of manufacturing a metal plate by pressing a punch against a plate-shaped metal material.
A first press step of forming a first recess group including one or more recesses on a machined surface of the plate-shaped metal material by a punch provided with one or a plurality of convex portions arranged side by side on the tip surface.
By punching a plurality of or one convex portion arranged side by side on the tip surface, a second recess group including a plurality or one recess is formed on the surface to be machined with at least a part of the formation area of the first recess group. A method for manufacturing a metal plate, which comprises a second pressing step of forming each recess of the second recess group so as to be separated from each recess of the first recess group.
The method for manufacturing a metal plate according to claim 18, wherein the separation distance between the recesses of the first recess group and the recesses of the second recess group adjacent to each other is less than 100 μm.
The punch used in the first pressing step and the punch used in the second pressing step have a tip surface having the same shape.
According to claim 18 or 19, the punch is pressed onto the surface to be machined in the second pressing step at a position deviated from the position where the punch is pressed against the surface to be machined in the first pressing step. The method for manufacturing a metal plate according to the description.
The first pressing step and the second pressing step are performed so that the recesses of the first recess group and the recesses of the second recess group are alternately arranged side by side on the surface to be processed, according to claims 18 to 20. The method for manufacturing a metal plate according to any one of the items.