Method of producing a plated product having recesses

A plated product and apparatus for forming recesses or grooves on material to be plated to produce such a product. The product includes material having a surface having many recesses, each having an opening of size d, where d is in the range 5-100 microns, a depth in the range from 0.2 d to d, or many grooves. In preferred embodiments, each groove or recess has an anchor portion. In some embodiments, each groove has a ridge portion at each of both edges of its opening. The angle of each groove to the surface of the material and each groove's depth and opening width are preferably in specified ranges. When the material is plated, part of the thin metal film enters the anchor portions of its grooves or recesses, so that the plated metal has superior capacity to resist peeling off of the plated metal.

BACKGROUND OF INVENTION
 1. Field of Invention
 This invention relates to a plated product in which the surface of a
 metallic or nonmetallic material is plated, and to a method and apparatus
 for producing it.
 2. Prior Art
 When the surface of a metallic or nonmetallic material is to be plated, it
 has been conventionally attempted to form fine recesses on the material
 before plating it, so as to enhance the adhesion of the material with a
 thin film of metal (plating). To form the recesses, various methods have
 been proposed. For example, in a certain method, fine powder particles are
 caused to hit the material. In another method, a certain kind of substance
 or fine particles that are dissolvable in a specified solution are
 previously embedded near the surface of the material, or mixed with the
 material, and the substance or fine particles are then dissolved in the
 solution.
 In the former method, the sizes of the fine powder particles range from
 several tens to several hundreds of .mu.m. Therefore, the fine recesses
 are formed by plastic deformation or a cutting force resulting from the
 collisions of the powder particles with the material to be plated. FIG. 1
 (a) shows a recess mainly formed by the plastic deformation made by the
 powder particles hitting the surface of the material at substantially
 right angles to it. FIG. 1 (b) shows a recess mainly formed by the cutting
 force formed by the powder particles hitting the surface of the material
 at an acute angle of incidence to the surface. Each of these recesses has
 a form that opens outwards, like a state after a meteorite has collided
 with a planet. Therefore, when the surface of the material is plated, the
 adhesion of the thin film of metal to the surface depends on the thin film
 of metal's own adhesive force, the resistance due to the uneven surface of
 the material, and the area of adhesion. Therefore, the following problems
 have occurred:
 When a force is applied in a direction substantially parallel to the
 surface of the material, not only the thin film of metal's own adhesive
 force, but also a resistant force (peeling resistance) is generated, in
 response to the resistance due to the uneven surface of the material, and
 to the size of the area where the metal adheres to the surface of the
 material to be plated. When a force is applied at substantially right
 angles to the surface of the material, the adhesion of the thin film of
 metal to the surface of the material depends only on the adhesion force of
 the thin film of metal, and the resistance due to the uneven surface of
 the material and the size of the adhered area do not contribute to the
 retention of the thin film of metal on the surface of the material. Thus,
 when a mechanically great force such as a strong hitting force is applied
 to a part of the plated surface, a phenomenon of fine peeling occurs on
 that part of the plating. Further, if the force is repeated, then the
 peeling increases, so that the thin film of metal peels off the material.
 In the latter method, the sizes of the fine recesses on the surface of the
 material depend on the sizes of the substance or the particles embedded or
 mixed. The sizes of the fine recesses are less than 2.about.3 .mu.m. As in
 FIG. 2 (a), the size of the opening of a recess is small as compared with
 the size of the entire recess. Therefore, in plating a material, the metal
 tends not to enter the recess. FIG. 2 (b) shows that the thin film of
 metal only blocks the opening of the recess. This leads to the adhesion of
 the thin film of metal to the surface of the material depending only on
 the thin film of metal's own adhesive force. Thus, when a mechanically
 large force is applied to the plated material, and is applied to a
 particular point on its surface, at right angles, the thin film of metal
 at that point peels off the material.
 SUMMARY OF INVENTION
 This invention has been created to resolve the above problems. Therefore,
 one object of this invention is to provide a plated product in which the
 thin film of metal tends not to peel off the surface of the material, and
 a method and apparatus for producing it.
 Another object of this invention is to provide a plated product in which
 the surface of a metallic or nonmetallic material is plated, that
 comprises a material of which the surface has many recesses, each having
 an opening of 5.about.100 .mu.m and a depth of 0.2 d.about.d (d: the
 diameter of the opening of a recess, .mu.m), and having an anchor portion,
 and a thin film of metal which covers the surface of said material and a
 portion of which film enters each said recess.
 Another object of this invention is to provide a method of producing a
 plated product in which the surface of a metallic or nonmetallic material
 is plated, that comprises causing the top of a needle or a drawn wire
 material of a diameter of 3.about.95 .mu.m to penetrate said surface of
 said material at angles of less than 90 degrees, but more than 45 degrees,
 withdrawing said needle or said drawn wire material from said material and
 repeating this process so as to provide at said surface of said material
 many recesses, each having an opening of 5.about.100 .mu.m and a depth of
 0.2 d.about.d (d: the size of the opening of a recess, .mu.m) and having
 an anchor portion, and covering said surface of said material that
 includes said recesses with a thin film of metal.
 A further object of this invention is to provide an apparatus for producing
 a plated product in which the surface of a metallic or nonmetallic
 material is plated, that comprises a needle or a drawn wire material of a
 diameter of 3.about.95 .mu.m, a retainer means for retaining the base
 portion of said needle or said drawn wire material so that said needle or
 drawn wire material is inclined at angles larger than 45 degrees, but less
 than 90 degrees, to said surface of said material, a material-fixing means
 to fix the material, and a means for elevating or lowering said retainer
 means.
 Still another object of this invention is to provide a plated product in
 which the surface of a metallic or nonmetallic material is plated,
 characterized by a plurality of grooves formed on the surface of said
 material, the width of the opening of each groove being 5.about.100 .mu.m
 and the depth of each groove being 0.2 b.about.b (b: said width of the
 opening, .mu.m), and the angle of each said groove to the surface of said
 material being within a range of more than 45 degrees, but less than 90
 degrees.
 A still further object of this invention is to provide a method of
 producing a plated product in which the surface of a metallic or
 nonmetallic material is plated, comprising causing a cutting blade having
 a thickness of 3.about.95 .mu.m to penetrate said surface of said material
 while said cutting blade is inclined to said surface of said material at
 angles within a range of more than 45 degrees, but less than 90 degrees,
 moving said cutting blade or said material to cause them to move relative
 to each other and repeating this process so as to provide at said surface
 of said material a plurality of grooves, many running in different
 directions, the width of the opening of each groove being 5.about.100
 .mu.m and the depth of each groove being 0.2 b.about.b (b: said width of
 the opening, .mu.m), and covering said surface of said material that
 includes said grooves with a thin film of metal.
 Still another object of this invention is to provide an apparatus for
 forming a plurality of grooves on the surface of a nonmetallic or metallic
 material for a plated product, comprising a retainer means for retaining
 the base portion of said cutting blade having a thickness of 3.about.95
 .mu.m so that said cutting blade is inclined to said surface of said
 material at angles within a range of more than 45 degrees, but less than
 90 degrees, a material-fixing means to fix said material, a means for
 elevating or lowering said retainer, a first moving means to move said
 retainer means in the direction that the blade of said cutting blade is
 directed, and a second moving means to move said material-fixing means
 horizontally.
 A still further object of this invention is to provide a plated product in
 which the surface of a metallic or nonmetallic material is plated,
 characterized by many grooves formed on the surface of said material, the
 width of the opening of each groove being 5.about.100 .mu.m and the depth
 of each groove being 10.about.90% of the thickness T of a plated layer,
 the angle of each said groove to the surface of said material being within
 a range of more than 30 degrees, but less than 150 degrees, and each
 groove being provided at each of both edges of its opening with a ridge
 portion whose height is 10.about.90% of said thickness T of said plated
 layer.
 Still another object of this invention is to provide a method of producing
 a plated product in which the surface of a metallic or nonmetallic
 material is plated, comprising causing a, cutting blade having a thickness
 of 3.about.95 .mu.m to be pressed on said surface of said material while
 said cutting blade is inclined to said surface of said material at angles
 within a range of more than 30 degrees, but less than 150 degrees, and
 moving said cutting blade or said material to cause them to move relative
 to each other, and repeating this process so as to provide at said surface
 of said material many grooves, many running in different directions, the
 width of the opening of each groove being 5.about.100 .mu.m, and the depth
 of each groove being 10.about.90% of the thickness T of a plated layer or
 2.about.18 .mu.m, and to provide ridge portions, the height of each of
 which is 10.about.90% of the thickness T of a plated layer or 2.about.18
 .mu.m, and covering said surface of said material that includes said
 grooves and ridge portions by metal plating.
 A still further object of this invention is to provide, in producing a
 plated product in which the surface of a metallic or nonmetallic material
 is plated, an apparatus for forming grooves and their ridge portions on
 the surface of said material comprising a retainer means for retaining a
 cutting blade having a thickness of 3.about.95 .mu.m so that the blade
 surface of said cutting blade is inclined to said surface of said material
 at angles within a range of more than 30 degrees, but less than 150
 degrees, a material-fixing means to fix said material, a means for
 elevating or lowering said retainer means, a first moving means to move
 said retainer means in the direction in which the blade of said cutting
 blade is directed, and a second moving means to move said material-fixing
 means horizontally.
 This invention provides a plated product comprising a material of which the
 surface has many recesses or grooves that have anchor portions. A part of
 a plating metal enters the recesses or grooves. Also, each groove can be
 provided with a ridge portion at each of both edges of the opening of each
 groove. Therefore, the plating metal is made to strongly adhere to the
 material so that the plated product produced by this invention has a
 superior technical effect in that the thin film of metal tends to not peel
 off the surface of a material.

DESCRIPTION OF THE PREFERRED EMBODIMENTS
 Embodiment 1
 Below, we explain, in detail, by referring to FIGS. 3 and 4, an apparatus
 to be used in a first embodiment that causes a needle to penetrate the
 surface of a material M, thereby roughening it. As in FIG. 3, a moving
 mechanism 12 is disposed on the lowermost part in the cavity of a column 1
 C-shaped in cross-section. On the upper surface of the moving mechanism
 12, a material-fixing-mechanism 2, which can fix the material M, is
 disposed. The moving mechanism 12 is adapted to move the material-fixing
 mechanism 2 in a horizontal plane.
 A recess-forming mechanism 3 is disposed at a position just above the
 material-fixing-mechanism 2. The recess-forming mechanism 3 comprises a
 retainer 5, a mounting member 6, a motorized cylinder 7, and a mounting
 member 8. The cylinder 7 is mounted on the mounting member 8, which is
 mounted on the uppermost part within the cavity of the column 1. The
 retainer 5 is connected to the lower end of the piston rod of the cylinder
 7, and adapted to be moved, through a guide member 6, by the actuation of
 the cylinder 7.
 The retainer 5 can retain the base portions of a. plurality of needles or
 drawn wires, each having a diameter of 3.about.95 .mu.m, while the needles
 or wires are inclined at angles of less than 90 degrees, but more than 45
 degrees, to the surface of the material. In this embodiment, four needles
 4 are retained by the retainer 5. Two pairs of oppositely arranged needles
 are so arranged that each of four needles 4 is disposed at each of four
 vertexes of one square. Simultaneously, one pair of needles 4 are disposed
 on one of two diagonal lines of the square. In other words, the one pair
 of needles 4 are disposed on the diagonal line of the square such that
 they are oppositely positioned to each other at respective vertexes.
 Therefore, in FIG. 3 one needle 4 is behind the other needle. Thus, only
 three needles can be seen in FIG. 3. Each needle has a diameter of 8
 .mu.m, and is inclined at an angle of about 80 degrees to the surface of
 the material. The cylinder 7 can act as a means for elevating or lowering
 the retainer 5.
 A controller 9, which is adapted for detecting a reaction force against the
 cylinder 7 so as to generate a command to control the descending force of
 the cylinder 7, is electrically connected to it.
 By using the thus-constructed apparatus, the surface of the material M, an
 aluminum plate 10.times.60.times.1 (mm), was roughened for use as a plated
 product. The aluminum plate was fixed by the material-fixing mechanism 2.
 Then, the cylinder 7 was actuated so as to have the retainer 5 and the
 needles 4 descend, thereby causing the needles 4 to penetrate the surface
 of the aluminum plate. Usually, the stiffness of the aluminum plate is
 lower than that of the needles 4. Therefore, even when the four needles 4,
 inclined in different directions from each other, are urged to penetrate
 the plate, the plate suffers the plastic deformation while allowing the
 advance of the needles 4. Therefore, the tops of four needles 4 can
 penetrate the aluminum plate. However, each of recesses thus formed is
 somewhat deformed. Thereafter, the cylinder 7 was actuated to be retracted
 so as to have the needles 4 and the retainer 5 ascend, so that the needles
 4 were withdrawn from the aluminum plate. Thus, a plurality of recesses,
 each having an anchor, on the surface of the aluminum plate, were
 obtained. Thereafter, the aluminum plate, provided with the recesses, was
 copper-plated to obtain a desired plated product. The aforesaid anchor
 portion means a hollow (a), i.e., as in FIG. 4, a part that is laterally
 hollowed out from a line which is drawn from the edge of the opening of a
 recess and that is perpendicular to the surface of a material.
 In this embodiment, the number of penetrating needles per 1 cm.sup.2 of the
 surface of the aluminum plate varies. The number of penetrating needles
 corresponds to the number of recesses. Each recess has an opening of 10
 .mu.m and a depth of 5 .mu.m.
 The plated plate was cut into a plurality of test pieces. Thereafter,
 bilaterally swinging fatigue tests (a repeated flex test) were carried out
 by bending each test piece 10,000 times. After each test a thin film of
 metal covering the surface of a piece was checked to see if there was a
 peeled part. The results are shown in Table 1.
 TABLE 1
 Method of Roughening the Percentages of Test Pieces
 Surface of a Material Having Peeled Parts
 Conventional Chemical Etching More than 60%
 Methods Shot Peening (Surface More than 50%
 Roughness 55 .mu.m)
 Shot Peening (Surface More than 40%
 Roughness 8 .mu.m)
 This Invention Number of Penetrating More than 35%
 Needles (5,000/cm.sup.2)
 Number of Penetrating Less than 10%
 Needles (10,000/cm.sup.2)
 Nurnber of Penetrating Less than 1%
 Needles (250,000/cm.sup.2)
 A certain degree of peeling occurred on less than 10% of the total test
 pieces that had recesses of 10,000/cm.sup.2, each recess being provided
 with an anchor. A certain degree of peeling occurred on less than 1% of
 the total test pieces that had recesses of 250,000/cm.sup.2, each recess
 being provided with an anchor. A certain degree of peeling occurred on
 more than 35% of the total test pieces that had recesses of
 5,000/cm.sup.2, each being provided with an anchor. This type of test
 piece has no utility.
 A preferable degree of peeling is less than 30% of the total test pieces.
 Table 1 shows that many recesses that each had an anchor portion provided
 on the surface of the aluminum plate caused a thin film of metal to be
 unlikely to be peeled off the aluminum plate.
 Next, control tests by conventional methods, for comparing them with the
 results obtained from the first embodiment of this invention, were carried
 out. On an aluminum plate as used in the first embodiment, a chemical
 etching test and a shot peening test were carried out. The results are
 shown in Table 1.
 As in Table 1, a certain degree of peeling occurred on more than 60% of the
 total test pieces which were roughened by a chemical etching. Also, a
 certain degree of peeling occurred on more than 50% of the total test
 pieces subjected to a shot peening and that had a surface roughness of 55
 .mu.m. Each test piece was roughened by causing shots, each 0.8 mm in
 diameter, to hit the test piece at a speed of 70 m/sec. Also, a certain
 degree of peeling occurred on more than 40% of the total test pieces
 subjected to a shot peening and that had a surface roughness of 8 .mu.m.
 Each test piece was roughened by causing shots, each 0.2 mm in diameter,
 to hit the test piece at a speed of 30 m/sec.
 In the first embodiment, the size of the opening of a recess and the depth
 of the recess were changed to have different values.
 As a result, when the size of the opening of a recess was less than 5
 .mu.m, the binding power between the molecules of a thin film of metal was
 greater than that between the molecules of the thin film of metal and the
 aluminum plate, or was greater than the gravitational force affecting
 them. Therefore, the metal could not enter the recess of the aluminum
 plate. When the size of the opening of a recess was more than 100 .mu.m,
 the metal was able to enter the recess of the material. However, in that
 case any part that adhered to the bottom surface of the recess resembled
 the case where the surface of the material that had no recess was covered.
 This led to the same result as in the conventional methods. Also, the
 adhesion properties were the same as in the conventional methods.
 When the depth of a recess was less than 20 percent of the size of an
 opening, no good peeling resistance could be obtained, and the performance
 remained the same as that of the conventional methods. When the depth of
 the recess was more than the size of an opening, energy was needed to
 cause a needle or the like to penetrate the material. However,
 nevertheless this had no effect.
 The size of a needle or drawn wire material to provide a recess that has an
 opening of 5 .mu.m was about 3 .mu.m. The size of a needle or drawn wire
 material to provide a recess that has an opening of 100 .mu.m was about 95
 .mu.m. Therefore, to provide a recess that has an opening ranging from 5
 .mu.m to 100 .mu.m, it is preferable to use a needle or drawn wire
 material that has a size of 3 .mu.m to 95 .mu.m in diameter.
 When the angle of a needle or drawn wire material to the aluminum plate was
 less than 45 degrees or more than 90 degrees, the adhesion of the plating
 metal to the aluminum plate was poor.
 Embodiment 2
 Below, a second embodiment will be explained by referring to FIG. 5. In the
 second embodiment, the material-fixing mechanism 2 and the moving
 mechanism 12 were the same as those used in the first embodiment. However,
 in the second embodiment, a recess-forming mechanism 10 comprises two
 pairs of oppositely arranged retainers 5 and their related elements. One
 pair of retainers 5 and their related elements are so arranged that each
 retainer 5 and its related element of the pair are disposed at each vertex
 of one pair of opposing vertexes of one square. Simultaneously, the one
 pair of retainers 5 and their related elements are positioned on the
 diagonal line of the square connecting the opposing vertexes. Therefore,
 one retainer 5 of the pair and its related elements are behind the other
 retainer 5 and its related elements. Thus, only three retainers 5 and
 their related elements can be seen in FIG. 5. Each retainer 5 is connected
 to the lower end of the piston rod of a small motorized cylinder 11. The
 retainer 5 is adapted to ascend or descend through a guide member 6 by the
 actuation of the cylinder 11. The guide members 6 are mounted, by means of
 mounting members 8, on the uppermost part within the cavity of the column
 1. A single needle 4 is retained by each retainer 5, while each needle is
 inclined at an angle of about 70 degrees to the surface of the material M.
 Each needle 4 can independently ascend or descend by means of each
 retainer 5, by the actuation of the cylinder 11.
 In the second embodiment, the same technical effects as those obtained in
 the first embodiment were obtained.
 Embodiment 3
 Next, we explain, in detail, by referring to FIGS. 6 and 7, an apparatus to
 be used in a third embodiment that causes razor-like cutting blades to
 penetrate the surface of an aluminum plate, to roughen it. As in FIG. 6, a
 moving mechanism 222 is disposed on the lowermost portion within the
 cavity of a C-shaped column 21. A material-fixing mechanism 22 for fixing
 a material M is disposed over the moving mechanism 222. The moving
 mechanism 222 acts as a second moving means and can move the
 material-fixing mechanism 22 in a horizontal plane.
 A groove-forming mechanism 23 is disposed at a position just above the
 material-fixing mechanism 22 in the column 21. The groove-forming
 mechanism 23 comprises a motorized cylinder 27 mounted by means of a
 mounting member 29 on a moving mechanism 28, which acts as a first moving
 means and is mounted on the uppermost part within the cavity of the column
 21, a guide member 26 disposed below the cylinder 27 and connected to the
 lower part of the cylinder 27, and a retainer 25 for retaining three pairs
 of razor-like cutting blades 24. The retainer 25 is connected to the lower
 end of the piston rod of a motorized cylinder 27. The base portions of the
 blades 24 can be retained by the retainer 25, so that each blade can
 incline to the surface of the material at angles of more than 45 degrees,
 but less than 90 degrees. In this embodiment each blade is inclined at an
 angle of about 60 degrees.
 The retainer 25 is adapted to retain a razor-like cutting blade of a
 thickness of from 3 to 95 .mu.m. In this embodiment a razor-like cutting
 blade having a thickness of 8 .mu.m was used. The shape of the edge
 portion of each blade is acute-angled so as to give a cross-sectional
 shape to a groove in the material, as in FIG. 7. The cylinder 27 acts as a
 means for elevating or lowering the retainer 25 through a guide member 26.
 Therefore, the retainer 25 can be moved to ascend or descend by the
 actuation of the cylinder 27. The moving mechanism 28 is adapted to move
 the cylinder 27 horizontally so that the retainer 25 is caused to move
 backward or forward in the longitudinal direction of the razor-like
 cutting blade 4.
 A controller 20 positioned above the column 21 is electrically connected to
 the motorized cylinder 27. The controller 20 acts as a control means to
 detect any reaction force against the motorized cylinder 27 so as to
 generate a command to control the pressing force of the cutting blades 4
 on the material M.
 By using the thus-constructed apparatus, the surface of the aluminum plate
 was roughened for use as a plated product. This roughening was done before
 the surface of the aluminum plate to be a plated product was plated.
 First, the plate was fixed to the material-fixing mechanism 22. Then, the
 motorized cylinder 27 was actuated to extend so as to have the cutting
 blades 24, the retainer 25, and so forth, descend, under the control of
 the controller 20. This caused the cutting blades 24 to penetrate the
 surface of the plate in a desired depth. Thereafter, the cutting blades
 24, the motorized cylinder 27, and so forth, were moved by the moving
 mechanism 28 in the longitudinal directions of the cutting blades 24 so
 that the surface of the plate was cut to form grooves thereon. When the,
 cutting blades 24 were moved a predetermined distance, the motorized
 cylinder 27 was actuated to retract, to have the retainer means 25 and so
 forth ascend, thereby withdrawing the cutting blades 24 from the surface
 of the plate. Then, the plate was moved by the moving mechanism 222 in a
 predetermined direction.
 By repeating this operation, many grooves on the aluminum plate were
 obtained that inclined to the surface of the surface of the plate at an
 angle of about 60 degrees. When the angle of a razor-like cutting blade to
 the aluminum plate was less than 45 degrees or more than 90 degrees, the
 adhesion of the plating metal to the aluminum plate was not good.
 The pattern on the surface of the plate was in a lattice form. However, the
 pattern may be in a diamond form.
 After this operation, the surface of the plate, provided with many grooves,
 was plated to obtain a plated product.
 The cross-sectional shape of the groove obtained in this embodiment can be
 seen in FIG. 7. It had an anchor portion, which means a hollow (a), i.e.,
 a part that is laterally hollowed out from a line which is drawn from the
 edge of the opening of the groove and that is perpendicular to the surface
 of the aluminum plate.
 In this embodiment, 20 grooves per 1 cm were obtained. The size of the
 opening of each groove was 10 .mu.m and the depth of it was 5 .mu.m.
 Then, the aluminum plate was copper-plated to make a test piece. The plated
 plate was cut into a plurality of test pieces.
 Thereafter, bilaterally swinging fatigue tests (a repeated flex test) were
 carried out 10,000 times on each piece. After each test a thin film of
 metal covering the surface of a piece was checked to see if any peeled
 part was observable. The results are shown in Table 2.
 TABLE 2
 Percentages of Test
 Method of Roughening the Pieces Having Peeled
 Surface of a Material Parts
 Conventional Chemical Etching More than 60%
 Methods Shot Peening (Surface More than 50%
 Roughness 55 .mu.m)
 Shot Peening (Surface More than 40%
 Roughness 8 .mu.m)
 This Invention Cutting by Razor-Like Cutting Less than 5%
 Blades (Opening: 10 .mu.m, Depth:
 5 .mu.m, Lattice Lines: 20/cm)
 Since a part of the thin film of metal entered the anchor portions of the
 grooves, the plated product had been provided with the desired peeling
 resistance.
 A certain degree of peeling occurred on less than 5% of the total test
 pieces prepared by this invention. Table 2 shows that a plurality of
 grooves, each groove being provided with an anchor portion as in FIG. 7,
 provided on the surface of a material, caused the thin film of plated
 metal hardly to peel off. The pattern provided on the surface of the
 material by those grooves that had an anchor portion may be in a lattice
 form or in a diamond form. They do not prevent the grooves from
 functioning as anchor portions. However, it is preferable that any two
 adjoining grooves be arranged not in parallel.
 Next, control tests by conventional methods, for comparing them with the
 results obtained from the first embodiment of this invention, were carried
 out. On an aluminum plate as used in the third embodiment, a chemical
 etching test and a shot peening test were carried out. The results are
 shown in Table 2.
 As in Table 2, a certain degree of peeling occurred on more than 60% of the
 total test pieces which were roughened by a chemical etching. Also, a
 certain degree of peeling occurred on more than 50% of the total test
 pieces that had a surface roughness of 55 .mu.m. Each test piece was
 roughened by causing shots, each 0.8 mm in diameter, to hit the test piece
 at a speed of 70 m/sec. Also, a certain degree of peeling occurred on more
 than 40% of the total test pieces that had a surface roughness of 8 .mu.m.
 Each test piece was roughened by causing shots, each 0.2 mm in diameter,
 to hit the test piece at a speed of 30 m/sec.
 In this embodiment, when the width of the opening of a groove was less than
 5 .mu.m, the binding power between the molecules of a thin film of metal
 was greater than that between the molecules of the thin film of metal and
 the aluminum plate, or was greater than the gravitational force affecting
 them. Therefore, the metal could not enter the groove of the aluminum
 plate. When the width of the opening of a groove was more than 100 .mu.m,
 the metal was able to enter the groove of the aluminum plate. However, in
 that case no part that adhered to the groove did so effectively function
 as in a groove that has an anchor portion. This resembled the case where
 the surface of the aluminum plate that had no groove is covered. This led
 to the same result as in the conventional methods. Also, the adhesion
 properties were the same as in the conventional methods.
 The thickness of a razor-like cutting blade to provide a groove that has a
 width of an opening of 5 .mu.m was about 3 .mu.m. The thickness of the
 razor-like cutting blade to provide a groove that has a width of an
 opening of 100 .mu.m was about 95 .mu.m. Therefore, to provide a groove
 that has a width of an opening ranging from 5 .mu.m to 100 .mu.m, it is
 preferable to use a razor-like cutting blade that has a thickness of 3
 .mu.m to 95 .mu.m.
 When the depth of a groove was less than 20 percent of the width of the
 opening of the groove, the peeling resistance could not be improved, and
 the performance remained the same as in the conventional methods. When the
 depth of the groove was more than the width of an opening, energy was
 needed to cause a cutting blade to penetrate the material. However,
 nevertheless this had no such a good effect as a groove that has an anchor
 portion.
 Embodiment 4
 Below is a fourth embodiment of this invention. In this embodiment, as in
 FIG. 8, a single-blade construction was used. In it a groove-forming
 mechanism 23 comprises two set of retainers 25 and their related elements.
 Each cutting blade 24 is retained by each retainer 25, each being adapted
 to ascend or descend by the actuation of each motorized cylinder 27. Each
 cylinder 27 is mounted by means of a mounting member 28 on the uppermost
 part within the cavity of a C-shaped column 21.
 Each cutting blade 24 can independently ascend or descend. In this case the
 pattern formed by grooves on the surface of the material was zigzag. The
 cutting blade was of a razor-like form. However, it is not limited to that
 form, if it has a high stiffness. For instance, a band-plate having a
 narrow width can be used. In this embodiment, each blade 24 was arranged
 to incline at an angle of about 80 degrees. However, the groove-forming
 mechanism 23 can be arranged so that each blade 24 is inclined at angles
 in a range from 45 degrees to 90 degrees to the surface of the material.
 As a means for elevating or lowering the retainer, the motorized cylinder
 27 was used in this embodiment. However, it is not limited to a motorized
 cylinder. For instance, a hydraulic cylinder can be used.
 Embodiment 5
 Below is a fifth embodiment of this invention. In this embodiment, as in
 FIG. 9, an apparatus to form grooves and ridges on the surface of an
 aluminum plate 10.times.60.times.1 (mm) is provided. In it a rotary-disk
 cutting blade 31 can be rotated and horizontally moved on the surface of
 the aluminum plate while the blade is pressed against the surface, to
 roughen it.
 The apparatus comprises a groove-forming mechanism 36, a material-fixing
 mechanism 33, and a moving means 37. The moving means 37 acts as a second
 moving means. The groove-forming mechanism 36 comprises a moving mechanism
 35, which acts as a first moving means, a retainer 32 to retain a
 pneumatic motor 38 via a universal coupling 345, a motorized cylinder 34
 to have the retainer 32 ascend or descend, a guide member 344, and a
 horizontally-moving mechanism 41 mounted on the uppermost part within the
 cavity of a C-shaped column 39. The motorized cylinder 34 is mounted on
 the moving mechanism 35, which is mounted on the horizontally-moving
 mechanism 41. To the lower end of the piston rod of the motorized cylinder
 34, the retainer 32 is connected. The retainer 32 can be moved up or down
 within the guide member 344. The rotary-disc cutting blade 31 has a
 diameter of 20 mm and a thickness of 8 .mu.m.
 The rotary-disk cutting blade 31 is rotatably mounted on the lower end of
 the pneumatic motor 38. By the universal coupling 345, the pneumatic motor
 38 and the blade 31 can incline to the surface of the aluminum plate, at
 angles from 30 to 150 degrees. In this embodiment the surface of the blade
 31 was inclined at an angle of about 60 degrees. The moving means 35 is
 adapted to move the motorized cylinder 34 and the retainer 32 in the
 direction that the blade of the rotary-disk cutting blade is directed. The
 moving mechanism 37 is adapted to horizontally move the material-fixing
 means 33. The horizontally-moving mechanism 41 is adapted to horizontally
 move the cylinder 34 and its related parts.
 Above the column 39, a controller 30 is disposed. It is electrically
 connected to the motorized cylinder 34, and acts as a control means. It
 can detect a reaction force against the cylinder 4 so as to generate a
 command to control the pressing force of the rotary-disc blade 31 on the
 aluminum plate.
 Below is explained the method of roughening the surface of the aluminum
 plate, using the thus-constructed apparatus. This roughening was done
 before the surface of the aluminum plate was plated to form a plated
 product.
 First, the aluminum plate was fixed to the material-fixing means 33. Then,
 compressed air was supplied to the pneumatic motor 38 to rotate the
 rotary-disk cutting blade 31. Thereafter, the motorized cylinder 34 was
 actuated to have its piston rod extend so as to have the rotary-disk
 cutting blade 31, the air motor 38, the retainer 32, and so forth,
 descend, under the control of the controller 30. This caused the
 rotary-disk cutting blade 31 to press the surface of the aluminum plate by
 a force of a specified degree. Then, the rotary-disk cutting blade 31, the
 air motor 8, and so forth, were moved by the moving mechanism 35 in the
 direction that the rotary-disk cutting blade 31 was rotated. Thus, the
 surface of the aluminum plate was cut to form grooves thereon.
 When the cutting blade 31 was moved a predetermined distance, the motorized
 cylinder 34 was actuated to retract, to have the retainer 32 and so forth
 ascend, thereby separating the rotary-disk cutting blade 31 from the
 aluminum plate. Then, the aluminum plate was moved by the moving mechanism
 37 in a predetermined direction. If desired, the retainer 32, the
 rotary-disk cutting blade 31, and so forth, can be horizontally rotated by
 the horizontally-moving mechanism 41. Thus, the movements of the
 rotary-disk cutting blade 31 caused the aluminum plate to be cut to form
 grooves.
 Simultaneously with the cutting of grooves, as in FIG. 10, a part of the
 aluminum plate was raised by the rotary-disk cutting blade 31 to form
 ridge portions (n) at both edges of the opening of the groove.
 By repeating this operation, many grooves were formed that inclined to the
 surface of the aluminum plate at an angle of about 60 degrees. Further,
 ridge portions were formed along the edges of the openings of the grooves.
 The pattern by the grooves on the surface of the material was in a lattice
 form. However, the pattern may be in a diamond form.
 After the operation, the surface of the aluminum plate, provided with many
 grooves and ridge portions, was plated to obtain a plated product. Since a
 part of the thin film of metal entered each groove so that the anchor
 portion strongly grasped the metal entered therein, the plated product was
 provided with the desired peeling resistance.
 The aforesaid anchor portion means a hollow (a), i.e., as in FIG. 10, a
 part that is laterally hollowed out from a line which is drawn from the
 edge of the opening of a groove and that is perpendicular to the surface
 of the aluminum plate. Also, (b) denotes the depth of a groove, and (c)
 denotes the height of the ridge portion of the groove.
 When the angle of the rotary-disk cutting blade to the surface of the
 aluminum plate was less than 30 degrees, the adhesion of the plating metal
 to the aluminum plate was poor. When the angle of the rotary-disk cutting
 blade to the surface the aluminum plate was more than 150 degrees, the
 adhesion of the plating metal to the aluminum plate was also poor.
 Therefore, preferably the angle of the cutting blade to the surface of a
 material ranges from 30 to 150 degrees. The cross-sectional shape of the
 groove obtained in this embodiment can be seen in FIG. 10. The width of
 the opening of the groove was 10 .mu.m, the depth of it was 8 .mu.m, and
 the height of the ridge portion was 4 .mu.m. There were 20 grooves per 1
 cm. The pattern of the grooves on the aluminum plate was in a lattice
 form.
 After the cutting operation, the aluminum plate was copper-plated to make
 test pieces.
 Then, bilaterally swinging fatigue tests (a repeated flex test) were
 carried out 10,000 times on each piece. After each test a thin film of
 metal covering the surface of a piece was checked to see if any peeled
 part was observable. The results are shown in Table 3.
 TABLE 3
 Percentages of Test
 Method of Roughening Pieces Having Peeled
 the Surface of a Material Parts
 Conventional Methods Chemical Etching More than 65%
 Shot Peening (Surface More than 55%
 Roughness 60 .mu.m)
 Shot Peening (Surface More than 45%
 Roughness 120 .mu.m)
 This Invention Cutting by Rotary-Disk Less than 5%
 Cutting Blades (Depth:
 8 .mu.m, Height: 4 .mu.m,
 Lattice lines: 20/cm)
 A certain degree of peeling occurred on less than 5% of the total test
 pieces prepared by this invention. Table 1 shows that a plurality of
 grooves, each groove being provided with anchor portions (n) as in FIG.
 10, provided on the surface of a material, caused the thin film of metal
 to hardly peel off. When the groove and its ridge portion were made to be
 in a curved form, or in a different combined form, the same results were
 obtained. Also, when the depth of the groove and the height of the ridge
 portion of the groove were changed within a predetermined range, the same
 results were obtained.
 As in Table 3, a certain degree of peeling occurred on more than 65% of the
 total test pieces which were roughened by a chemical etching. Also, a
 certain degree of peeling occurred on more than 55% of the total test
 pieces that had a surface roughness of 60 .mu.m. Each test piece was
 roughened by peening, with each shot being 0.8 mm in diameter, to hit the
 test piece at a speed of 70 m/sec. Also, a certain degree of peeling
 occurred on more than 45% of the total test pieces that had a surface
 roughness of 12 .mu.m. Each test piece was roughened by causing shots,
 each 0.2 mm in diameter, to hit the test piece at a speed of 30 m/sec.
 In this embodiment, when the width of the opening of a groove is less than
 5 .mu.m, the binding power between the molecules of a thin film of metal
 is greater than that between the molecules of the thin film of metal and
 the material, or is greater than the gravitational force affecting them.
 Therefore, the metal cannot enter the groove of the aluminum plate. When
 the width of the opening of a groove is more than 100 .mu.m, the metal can
 enter the groove of the material. However, in that case any part that
 adheres to the groove does not so effectively function as a groove that
 has an anchor portion. This resembles the case where the surface of the
 aluminum plate that has no groove is covered. This leads to the same
 result as in the conventional methods. Also, the adhesion properties are
 the same as in the conventional methods.
 The thickness of a rotary-disc cutting blade to provide a groove that has
 the width of the opening of a groove of 5 .mu.m was about 3 .mu.m. The
 thickness of the rotary-disc cutting blade to provide a groove that has
 the width of the opening of a groove of 100 .mu.m was about 95 .mu.m.
 Therefore, to provide a groove that has the width of the opening of a
 groove ranging from 5 .mu.m to 100 .mu.m, it is preferable to use a
 rotary-disc cutting blade that has a thickness of 3 .mu.m to 95 .mu.m.
 When the depth of a groove and the height of the ridge portion of the
 groove are less than 10 percent of the thickness of a plated layer,
 especially the shearing force at the contact area of the plating is
 weakened. This results in fewer anchor effects. When the depth of the
 groove and the height of the ridge portion of the groove are more than the
 thickness of the plated layer, the metal can enter the groove. Therefore,
 preferably the depth of a groove and the height of the ridge portion of
 the groove are less than 90 percent of the thickness of a plated layer.
 However, when the thickness of the plated layer at a portion where the
 ridge portion of a groove is located is high, the plated layer becomes
 uneven. Also, the binding power between the metal and the aluminum plate
 at that portion is weak.
 Therefore, the plating metal that adheres to the groove has less effect to
 function as in a groove that has an anchor portion. This results in a
 plated layer that tends to be easily broken.
 Generally, the thickness of a plated layer ranges from 10 to 20 .mu.m. To
 obtain a good plated layer, the depth of a groove and the angle of the
 groove to the surface of a material should range from 2 to 18 .mu.m, and
 from 30 to 150 degrees, respectively, and the height of the ridge portion
 of the groove should range from 2 to 18 microns.
 The pattern provided on the surface of the aluminum plate by the grooves
 and their ridge portions was in a lattice form. However, it may be in a
 diamond form. Neither prevents the grooves or their ridge portions from
 functioning as anchor portions. However, it is preferable that any two
 adjoining grooves be arranged not in parallel in the cross section of the
 aluminum plate.
 The grooves and their ridge portions can be linear or curved, or in a
 combined form. The depth of a groove and the height of the ridge of the
 groove can be varied within a predetermined range.
 Further, the height of the ridge portion of a groove is preferably lower
 than the depth of the groove. As a means to form a groove and its ridge
 portion, any cutting blade that has a stiffness of a certain degree can be
 used. For instance, a razor-like blade, a band-plate having a narrow
 width, or a rotary-disk cutting blade having a desired thickness and
 diameter, can be preferably used. This cutting blade is caused to be
 pressed with a desired pressure against the surface of a material while
 the blade is moved, so that the surface of the material is cut or carved.
 In the above embodiment, the rotary-disk cutting blade 31 was rotated by
 the pneumatic motor 38. However, in place of it, an electric motor can be
 used to rotate it. It will cause the same operation and effects as those
 caused by the pneumatic motor 38.
 Also, the motorized cylinder 34 was used as an elevating or lowering means.
 However, the means is not limited to a motorized cylinder. For instance, a
 hydraulic cylinder can be used.
 As will be understood from the above explanation, by the fifth embodiment
 of this invention a plurality of grooves are formed on the surface of a
 material. The width of the opening of each groove is 5.about.100 .mu.m and
 the depth of each groove is 10.about.90% of the thickness T of a plated
 layer. The angle of each groove to the surface of the material is within a
 range of more than 30 degrees, but less than 150 degrees. Each groove is
 provided at each of both edges of its opening with a ridge portion, the
 height of which is 10.about.90% of the thickness T of the plated layer. A
 part of the thin film of metal enters the anchor portion of the groove.
 Therefore, the thin film of metal hardly peels off the surface of the
 material, as compared with the conventional plated products.
 Thus, this invention provides a plated product comprising a material of
 which the surface has many recesses or grooves that have anchor portions.
 Therefore, a part of a plating metal enters the anchor portions of the
 recesses or grooves. Since the anchor portions firmly grasp the plating
 metal entered, the plated metal of the product resists the force applied
 in a direction at substantially right angles, so as to prevent the plated
 metal from peeling off. Also, each of the grooves on the surface of the
 material can be provided with a ridge portion at each of both edges of its
 opening. Therefore, the plated metal that covers the grooves and ridge
 portions of the material also resists the force applied in a direction
 substantially parallel to the surface of the material so as to prevent the
 plated metal from peeling off. Therefore, the plated product produced by
 this invention has a superior technical effect in that the thin film of
 metal tends to not peel off the surface of a material.