DE10020590C2 - Multi-dimension strips and method to compensate for them - Google Patents

Description

The present invention relates to a multi-dimension strip or multi-oak strips and on a process for leveling or leveling the same, the multi-dimension strip being one which is gradual varies in thickness in its width direction. He is used to train electro African parts, for example lead frames or connection combs or Terminal comb strips (for power transistors), connections, connectors or Plugs, relay contacts, etc. are used. The present relates more precisely Invention on a multi-measure strips or multi-measure strips and a Method for balancing or straightening the same, the multiple dimension Strip is one that has a small amount of stress has load and is suitable for use as electronic parts.  

DE 198 18 286 C2 relates to a method for producing a Double standard strip with one or more thick parts on the surface along the length of the strip, starting from a flat strip and for use with electronic parts; furthermore it refers to a Intermediate material for producing a double standard strip in the process of Production of the double standard strip and a method for producing the Intermediate material.  

A multi-dimension strip or multi-unit strip is formed in such a way that its cross section varies in thickness in its width direction, the cross section being uniformly continuous or continuous in the longitudinal direction. As shown in FIGS. 1 and 2, it has one or two thick parts in its cross section.

There are several known methods for making this more fachmaß Strip. These include, for example, a back and forth Rolling (Japanese Patent Publication No. 42150/1984), a tandem rolling  (Japanese Patent Publications Sho 60-60010), a V- Stand casting or molding (Japanese patent publication Sho 52-10849), forging (Japanese Patent Publication No. 54462/1987) and one Cut from a uniformly thick strip. Your choice depends on the Productivity and the required quality. These procedures form with Aus the final or final multiple measure- or -eich cross-section from a plastic deformation.

A multi-dimension strip is placed on the fol edited in the appropriate way. First, it is put into a prescribed form Stamp punched and divided into two parts in the width direction. In the press The edge or edge of a thin part of the Multi-dimension strips with a width of between 0.5 and 2.0 mm slotted. Then it will have a nickel plating or coating and a gold point plating awarded. It is cut in length (200-300 mm). He becomes a bond or contact, wire bonding and resin molding or casting for to be determined Transistors subjected. The process or the process is carried out by a solder plate animals or coating and a truss or cross bar cutting completed.

Multi-dimension strips are usually caused by plastic deformation generated. The whole process consists of a rough shape or Raw forms from a flat strip, tempering or annealing or heat treat and a final or final rolling. The result therefore varies multi-dimensional strips in a reduction in the thickness and structure of thick parts to thin parts and it therefore also varies in the distribution of one Residual or internal stress from thick parts to thin parts. A rest stress due to the rough forming is almost completely caused by the subsequent annealing or annealing eliminated. However, another occurs Tension during the final rolling, which a Compression in thickness, expansion in width and expansion or Increases in length.

Conventional multi-dimension strips, which with the above Methods created have the following problems. multiple measure strips, which show an unsuitable or unevenly distributed residual tension are subject or are subject to deformation (such as  an elongation, a contraction, a curvature or curvature or Deflection, a cross or transverse bend or curvature and one Twisting or twisting) during stamping or punching and cutting dens for manufacturing in electronic parts (such as lead frames or connecting combs or frames with connecting legs and connections) subjected. This deformation occurs when there is an uneven tension or load is relieved and a voltage distribution changes. A Excessive deformation that occurs during machining causes the multi-dimension strip clogs the stamp or shape, causing the Punching speed is reduced or the press processing made difficult becomes. In addition, a deformation in the multi-dimension strip sets the Dimensional accuracy of the punched product.

An unevenly distributed residual voltage complicates the coplanarity of Conductors and the accuracy of conductor or lead positions due to a Buckling, cross-buckling, twisting etc. if the multi-dimension strip is processed in lead frames or connection combs. This results in one Bonding or contacting a displaced wire and an uneven one Conductor bond strength in the transistor mounting step. additionally bring twisted or twisted conductors and unevenly spaced conductors Difficulty assembling finished transistors on a circuit board with yourself. So bring multi-dimension strips with unevenly distributed Residual stress many problems as mentioned above with it.

The present invention has been made to overcome the above problems to address or treat. It is therefore an aim of the present Invention, a multi-dimension strip and a method for compensating or To provide leveling or straightening of the same.

That goal will by producing a multi-dimension strip, which has only a small amount degree of tension or stress, an examination for an own or Residual stress distribution under predetermined conditions, performing punching or stamping without causing deformation and a  Submitting to a suitable leveling or balancing for a load or voltage reduction achieved.

The first aspect of the invention is a multi-dimension strip with one Cross-section, which has one or more thin parts and thick parts, which are formed by rolling over its width, the cross cut is continuous or continuous in the longitudinal direction, wel cher is characterized in that the thin part has a hardness of H1 and thick part has a hardness of H2, the ratio of H1 / H2 between 0.9 and 1.15.

The multi-dimension strip, which is designed as mentioned above, has a very small difference in the residual or residual stress between the thin part and the thick part. (This residual voltage occurs because the Extent of machining and the structure from the thin part to the thick one Part vary during rolling.) The multi-dimension strip allows one to assess whether an internal tension or stress is uniformly distributed in it is or not. That is, the ratio of H1 / H2 shows the distribution of the Residual voltage.

The second aspect of the present invention is a multi-dimension Stripe as defined in the first aspect, wherein the thick part is only in that Center of the width is formed and the thin parts on both edges or Edges are formed and in which the cross section is uniform such that if the multi-dimension strip in its longitudinal direction (1.2 to 5 times its width) at five positions, one in the center of the width, one at the Border between the thin part and the thick part and one at each Edge or the edge of the thin part to be slit is cut, the Dimensional deviation between the two points (symmetrical relative to the Center of the width) in the cut surface is less than 0.15 mm the end where the cutting begins.

The value specified above allows one to judge whether there is a remainder voltage is suitable or evenly distributed or not. A residual tension tends to be in a special position in the case of multi-dimension Collect strips, which are a thick part and two thin parts on both Have sides of the same. In this way one can judge whether the given  Multi-dimension strips are suitable for further production or processing or not.

The third aspect of the present invention is a multi-dimension strip as defined in the first aspect, wherein two thick parts are symmetrical are formed with a thin part formed in the center of the width and thin parts on both edges outside the thick parts are formed, and wherein the cross section is uniform such that when the Multi-dimension strips in its longitudinal direction (1.2 to 5 times its width) at five positions, one at the center of latitude, one at the outer border between the thin part and the thick part and one at each edge or the edge of the thin part to be cut, the dimensions deviation between the two points (symmetrical to the center of the Width) in the cut surface is less than 0.15 mm at the end where the cutting begins.

The value specified above allows one to judge whether there is a remainder voltage is suitable or evenly distributed or not. A residual tension tends to be at a certain position in the case of a multi-dimension Stripe to collect, which two symmetrically formed, thick parts has, with a thin part between them. You can do that assess whether the given multi-dimension strip for processing or Processing is suitable or not.

The fourth aspect of the present invention is a multi-dimension strip which is defined in the first aspect, wherein the thick part only in that Center of the width is formed and the thin parts on both edges or Edges are formed and in which the cross section is uniform such that if the multi-dimension strip in its longitudinal direction (1.2 to 5 times its width) at five positions, one in the center of the width, one at the Border between the thin part and the thick part and one at each Edge or the edge of the thin part to be slit is cut, the Tilt angle of the cut, thin part less than 4 ° to the horizontal Baseline at the end is where the cutting begins.

The value specified above allows one to judge whether there is a remainder voltage is suitable or evenly distributed or not. A residual tension tends to be in a special position in the case of multi-dimension  Collect strips, which are a thick part and two thin parts on both Have sides of the same. It is therefore possible to have a transverse curvature or Cross curvature, twisting and arching or bending during manufacture to minimize multi-dimension strips.

The fifth aspect of the present invention is a multi-dimension strip as defined in the first aspect, wherein two thick parts are symmetrical are formed with a thin part formed in the center of the width and thin parts on both edges outside the thick parts are formed, and wherein the cross section is uniform such that when the Multi-dimension strips in its longitudinal direction (1.2 to 5 times its width) at five positions, one at the center of latitude, one at the outer border between the thin part and the thick part and one at each edge or the edge of the thin part to be cut is cut, the Nei angle of the cut, thin part less than 4 ° to the horizontal Baseline at the end is where the cutting begins.

The value specified above allows one to judge whether there is a remainder voltage is suitable or evenly distributed or not. A residual tension tends to be in a special position in the case of multi-dimension Gather strips, which are two symmetrically formed, thick parts with a thin part in between and two thin parts on both Sides of the same. It is therefore possible to have a transverse curvature, a twisting and buckling in the manufacture of multi-dimension strips minimize.

The sixth aspect of the present invention is a multi-dimensional Strip with a cross section, which one or more thin parts and has thick parts which are formed by rolling over its width, the cross section being uniformly continuous in the longitudinal direction, the Multi-dimension strips after rolling by application or application a strain or tension equalized or leveled which is a plastic deformation corresponding to 0.05 to 1 % of the elongation or elongation in the longitudinal direction causes or with itself brings.

Balancing or leveling in this way relieves the extra Compartmental strips of unevenly distributed residual tension. It is therefore  possible to minimize the deformation of multi-dimension strips, which occurs during editing.

Fig. 1 is a perspective view showing the multi-size strip according to the present invention.

Figs. 2A and 2B are the Mehrfachmaß strip according to the present invention, perspective views showing essential parts.

Fig. 3 is a perspective view showing another construction of the multi-size strip according to the present invention.

FIGS. 4A and 4B are perspective views showing the Wesent union parts of other Mehrfachmaß strip according to the present OF INVENTION dung.

FIGS. 5A and 5B are schematic diagrams according to show the cross section of the Mehrfachmaß strip of the present invention, wherein the cross section occurs after cutting.

Fig. 6A is a plan view of the multi-dimension strip according to the present invention, which was subjected to stamping and punching, and

Fig. 6B is a perspective view showing the lead frame formed by the punched multi-dimension strip.

FIGS. 7A and 7B are perspective views showing another construction of the Mehrfachmaß strip according to the present invention.

Fig. 8 is a schematic diagram showing the method of aligning the multi-dimension strip according to the present invention.

Fig. 9 is a schematic diagram showing the construction of the stamp used for balancing the multi-size strip according to the present invention.

Fig. 10 is a schematic diagram showing the change in cross section and the hardness that occurs during rolling in the manufacture of the multi-dimension strip.

The embodiments of the invention are described with reference to FIG enclosed drawings described.

The multi-gauge strip is designed to have one or more thick parts and thin parts in its width direction, with its cross-section being uniform and continuous in its longitudinal direction. Some typical structures of the multi-gauge Strip 1 are shown in Figures 1 to 4. The multi-dimension strip shown in Figure 1 is formed of a thick part 3 in the center of its width W and thin parts 2 and 2 on both sides of the thick part 3. That thick part 3 is formed in such a way that its walls have a certain angle of inclination (α) which is between 0 ° and 10 ° The multi-dimension strip 11 shown in Fig. 3 is made of two thick parts 13 and 13 and three thin parts 12. The two thick parts 13 and 13 are formed, the thin part 12 b being arranged between them, and the two thin parts or sections 12 a and 12 a are on the outside of the two thick parts Parts 13 and 13 formed. The thick parts 13 and 13 are designed such that their walls have a special angle of inclination (β) which is between 0 ° and 10 °.

The multi-dimension strip 1 or 11 is processed in electronic parts, such as in lead frames or connection combs for power transistors (see Fig. 6), connections, connectors or plugs and relay contacts. The multi-dimension strip 1 or 11 for lead frames or connection combs is made of pure copper, such as, for example, oxygen-free copper (C1020), electrolytic copper (C1100) and phosphorus-containing, deoxidized copper (C1201), or a copper alloy, such as Cu-0.1 Fe -0.03P, manufactures. The multi-dimension strip 1 or 11 for connections is made of a copper alloy (higher strength or strength), an Fe-Ni alloy, an iron alloy or a nickel alloy. It is also made from any other alloy.

As shown in FIGS. 1 and 3, the multi-dimension strip 1 or 11 differs from a flat strip which has a uniform thickness. It is produced by rough shaping or rough shaping (rolling or forging), annealing or annealing or heat treatment and finishing or finish rolling. The thick parts 3 and 13 and the thin parts 2 and 12 vary widely in hardness and grain size depending on the conditions (such as a reduction in thickness and the annealing temperature and time) of rough forming and finish rolling.

Furthermore, as shown in FIGS. 1 and 3, the multi-dimension strip 1 or 11 has one or two thick parts 3 or 13 on one side thereof. These parts have the following dimensions:
Thickness T _{1 of} the thin part 2 or 12 : 0.1-1.5 mm
Thickness T _{2 of} the thick part 3 or 13 : 3-20.2 mm
Width W of multi-dimension strip 1 or 11 : 30-200 mm
Width D _{1 of} the thick part 3 or 13 : 5-150 mm (or the sum of the widths if the multi-dimension strip has two thick parts 13 and 13 )

In addition, as shown in Fig. 7A, the multi-size strip 51 may be formed so that the thick part bulges upward or downward. In addition, as shown in FIG. 7B, the multi-size strip 61 may have grooves 64 and 64 which are longitudinally at the bottom and rear near the boundary between the thick part 63 and the thin part 62 . In other words, the present invention is directed to any multi-dimensional strip used for electronic parts. The multisize strips 51 and 61 shown in Figs. 7A and TB are examples having a thick part. The same idea is applied to those that have two thick parts (not shown).

According to the present invention, the multi-dimension strip 1 or 11 is characterized in that the thin part 2 or 12 has a certain hardness and that the thick part 3 or 13 has another certain hardness, the ratio of the former to the latter determining or is fixed. Since the thick part 3 or 13 and the thin part 2 or 12 are formed from a flat strip (of uniform thickness), they differ in hardness from each other depending on their reduction in thickness even if the raw material is the same. The hardness can be measured according to the hardness test methods (Vickers, Rockwell or Brinell), which are provided in JIS Z2244, JIS Z2465 and JIS Z2243. In the case of the multi-dimension strip 1 having a thick part 3 , the hardness H1 of the thin part 2 is measured on the line S ₁ and the hardness H2 of the thick part 3 is measured on the center line CL as shown in FIG. 1 is shown. Hardness is expressed in terms of an average or as an average of five measurements on each line.

In the case of the multi-size strip 11 having two thick parts 13 and 13 , the hardness H1 of the thin part 12 is measured on the center line CL of the multi-size strip 11, and the hardness H2 of the thick parts 13 and 13 becomes on the center line S ₂ measured from each of the thick parts as shown in FIG. 3. Hardness is expressed in terms of an average of five measurements on each line. The ratio of H1 / H2 should be in the range of 0.9 to 1.15, where H1 is the hardness of the thin part 2 or 12 and H2 is the hardness of the thick part 3 or 13 .

The reason why the ratio of H1 / H2 should be in the range of 0.9 to 1.15 is as follows. If the ratio is less than 0.9 or greater than 1.15, the multi-dimension strip 1 or 11 has such a large amount of non-uniform residual stress that it causes deformation (curvature, cross-curvature and twisting) during punching ( Fig. 6A), assembly of a transistor or a connection assembly. This greatly degrades productivity and yield. The ratio of H1 / H2 should be 0.9-1.15, preferably 0.95-1.10, more preferably 0.98-1.05. The number of measurements can be less than or greater than 5.

The multi-dimension strip is usually made from a flat strip (or raw material) via an intermediate product. Fig. 10 shows the rolling steps which are used for the production of the multi-dimension strip of the vorlie invention. The flat strip (raw material) should have a coarse or tube roll and a finish or finish roll with a suitable reduction in thickness under suitable heat treatment conditions according to its alloy composition and the finished cross section (thickness of the thick parts or sections and thin Parts or areas), so that the resulting multi-dimension strip has satisfactory mechanical properties (hardness, tensile strength, proof stress, elongation, etc.) and good electrical conductivity.

Flat strip (or raw material)

A blank or a plate Copper or a copper alloy is made by continuous casting or semi-continuous casting. The blank is placed in a sheet or sheet formed by hot rolling, cold rolling and heat treatment. The Sheet metal is slit into flat strips of the desired dimensions or cut. The flat strip can either be as rolled or as are heat treated or annealed. The flat strip thus obtained has a uniform or uniform hardness (H0) both in the longitudinal direction as well as in the width direction. The flat strip has a thickness of T0 on.

intermediate

The flat strip is subject to rough rolling or raw rolling through a Pilger roll stand or a roll stand, wel cher from a grooved roller and a flat roller together is set so that it is a thick part (with a thickness of T12) and a thin part Part (with a thickness of T11). A rough rolling becomes like this performed that the thickness reduction in the thick part is small and in the thin part is big. The thick part has a hardness of H12 and the thin one Part has a hardness of H11. Then H11 is bigger than H12 because of the thin part has a larger reduction value in thickness than the thick part.

The intermediate product obtained in this way is subjected to heat treatment or Annealing to regain ductility or stretchability or ver subject to malleability. The thick part has a hardness of H22 and that thin part has a hardness of H21. Then H22 = H21 because the thin part has a larger value of a thickness reduction than the thick part and it is softened more by the annealing or heat treatment.

Completed multi-dimension strip

The heat treated or ge annealed intermediate strip is under a finish rolling with a roller stand cast, which consists of a grooved roller and a flat roller is assembled. (The grooved roller points  a concave area with a desired depth at a prescribed Position in the width direction.) The thick part has a thickness of T32 and the thin part has a thickness of T31. The thick part has a hardness from H32 and the thin part has a hardness of H31. The values of Hardness depends on the reduction in thickness.

According to the present invention, the ratio of H31 / H32 are between 0.9 and 1.15. For this purpose it is necessary to use suitable Rolling conditions for a reduction in thickness and for annealing or heating to choose.

According to the present invention, the multi-dimension strip 1 or 11 should have a special displacement after a cutting. Cuts are made at specific positions, which are shown in FIGS. 1 to 4. A sample of length L ₂ (200-500 mm) is taken from the multi-measure strip 1 or 11 of a standard length L. Cuts are made at five positions, as shown in FIGS. 2 and 4. The length L _{1 of} a cut is 1.2 to 5 times the width of the multi-dimension strip 1 or 11 .

The extent and angle of a displacement are measured at the end at which cutting begins. The five positions for cutting (in the case of multi-dimension strip 1 ) are shown in Fig. 2. The first position e is in the center of the width W. The two th and third positions b ₁ and b ₂ are on the boundary between the thin part 2 and the thick part 3 . The fourth and fifth positions c ₁ and c ₂ should be 0.5 to 2.5 mm from both edges in the thin part 2 . These positions correspond to those which are to be slit in the stamping or stamping process in order to produce a lead frame or frame with connecting legs. Cutting should be carried out by electrical discharge machining or chemical etching in order to prevent renewed stresses or tensions from entering or being introduced into the multi-dimension strip 1 .

The length (L ₁ ) of the cut should be 1.2 to 5 times the width W of the multi-dimension strip 1 or 11 . (If the sample is cut over its entire length, it is impossible to measure the size of a shift.) If the length of the cut is less than 1.2 times the width W, a shift occurs due to an inherent or Residual tension not on. If the length of the cut is 5 times the width W, a shift due to a residual stress is affected by gravity.

A shift is measured in the following way. Assuming that the multi-size strip 1 has a width (W) of 65 mm, a sample with a length (L ₂ ) of 200 mm is taken and cuts (about 150 mm long in the longitudinal direction) are made by an electric one Spark machining or spark erosion is carried out at five positions (e, b ₁ , b ₂ , c ₁ , c ₂ ). Before cutting, at a ₁ and a ₂ (2 mm inside the shoulders of the thick part 3 ), e marks are made symmetrically relative to the central cutting line. The distance Δd between a ₁ and a ₂ is measured before and after cutting using a projector (with a magnification of 30 to 100).

The multi-dimension strip 11 shown in FIGS. 3 and 4 is tested in the same way as the multi-dimension strip 1 . That is, they are the same data or parameters in the sample length (L ₂ ), the width W, the cutting length and the cutting method. Cuts are made in five positions. The first position e is located in the center or center of the width W. The second and third positions b ₁ and b ₂ are located on the boundary between the outer, thin part 12 and the thick part 13 . The fourth and fifth positions c ₁ and c ₂ are located in the thin part 12 on both edges which have to be slit. Before cutting, marks at a ₁ and a ₂ (2 mm inside the shoulders of the thick parts 13 and 13 ) are made symmetrically to the central cutting line e. The distance Δd between a ₁ and a ₂ is measured before and after cutting using a projector (with a magnification of 30 to 100).

The amount of shift is obtained from equation (1) below.

d - Δd (1)

(where d is the length of the distance before cutting and Δd is the length of a Distance after cutting).

According to the present invention, that from equation (1) should be calculated value should be less than 0.15 mm.

The amount of displacement between two points a ₁ and a ₂ on the thick part of the multi-size strip is proportional to the magnitude of the residual stress stored in multi-size strip 1 or 11 . If the amount of displacement is larger than 0.15 mm, the following problems arise in the multi-size strip 1 , which has a thick part 3 , or in the multi-size strip 11 , which has two thick parts 13 and 13 , on. The multi-dimension strip (as a blank 1 A) does not allow smooth punching for manufacture in a lead frame or terminal comb ( 1 B), which are shown in FIGS. 6A and 6B. During punching, main body 3 A and connectors 2 B clog the punch press or die. Poor wire bonding or contacting and deformed connections also occur during assembly of a transistor or assembly of a connection. Therefore, the amount of displacement should be less than 0.15 mm, preferably less than 0.1 mm and most preferably less than 0.05 mm.

The displacement angle is measured in the following manner. Fig. 5 is a schematic diagram showing the cross section of the multi-dimension strip 1 which has been cut. (The cross section is seen in the direction of a cut.) The symbol 0 denotes the angle of inclination to the horizontal base line SL of the thin part 2 . The angle θ is determined by measuring the positions of P ₁ and P ₂ , which are shown in Fig. 5B. For a measurement, a sample of the multi-dimension strip 1 , in which cuts were made, is placed on a movable table 5 and moved under the projector 7 (with a magnification of 30 to 100). In other words, the length A and the length B are calculated from the positions P ₁ and P ₂ , and the angle of θ is obtained from the equation (2) below.

θ = tan ^-1 / (B / A) (2)

The same method as mentioned above is also applied to the multi-dimension strip 11 shown in FIGS. 3 and 4. That is, the outer thin part 12 a, which was cut at the outer boundary b ₂ between the thick part and the thin part, is examined under the projector and the angle of θ is calculated from the above equation (2) ,

According to the present invention, the angle of θ thus measured should be less than 4 °. The reason for this is explained below. The angle of inclination to the horizontal base line SL of the thin part after cutting is proportional to the extent of a residual stress stored in the multi-dimension strip 1 . If the angle of θ is larger than 4 °, the following problems occur in the multi-size strip 1 , which has a thick part 3 , or in the multi-size strip 11 , which has two thick parts 13 and 13 . The multi-dimension strip (as a blank 1 A) does not allow smooth punching for manufacture in a lead frame ( 1 B), which is shown in Fig. 6A. During stamping or punching, the main body 3 A and connectors 2 B clog the die. Furthermore, poor wire bonding and deformed terminals can occur during transistor assembly and terminal assembly. Therefore, the angle of inclination should be less than 4 °, preferably less than 3 ° and most preferably less than 2 °.

The direction of the angle of θ can be upward relative to the horizontal baseline SL. In this case too, the angle of inclination should be less than 4 °. In addition, the horizontal base line SL coincides with the lower surface of the multi-measure strip 1 or 11 .

Fig. 8 is a schematic diagram showing the voltage leveling machine for the multi-dimension strip 1 or 11 . The multi-dimension strip 1 or 11 , which has been subjected to a final rolling, slitting and winding, is passed through the leveling machine, which leveling or leveling by applying or applying tension to the following Way.

As shown in FIGS. 8 and 9A, the multi-dimension strip 1 is unwound from the dispensing roll or spool 38 and wound onto the tensioning roll or spool 39 . (The first step) This state is maintained while the feeding of the multi-size strip 1 is stopped. (The second step) The gripping cylinders 34 and 36 are lowered so that the thick part 3 and the thin parts 2 and 2 of the multi-dimension strip 1 are gripped by the mold or the stamp 30 . (The third step) The left punch 30 is moved to the left using the stretching cylinder 35 . (The fourth step) Since the right stamp 30 is fixed, the multi-dimension strip 1 receives a tensile force. The left punch 30 is moved a prescribed distance (which is necessary for leveling) and then the stretching cylinder 35 is stopped. (The sixth step)

The stretching cylinder 35 is actuated again, so that the punch 30 returns. (The seventh step) The left and right gripping cylinders 34 and 36 are raised to open the dies 30 and 30 so that the multi-size strip 1 is released. (The Eighth Step) The tension roller 39 is rotated to wind the leveled multi-dimension strip which is as long as the distance between the left and right dies 30 and 30 . (The Ninth Scripture) The third and subsequent steps are repeated. In addition, the distance between the two stamps or shapes 30 and 30 is the length of the multi-dimension strip 1 to be compensated for or adjusted at a time. The upper and lower stamps or shapes are designated or indicated with 31 and 32.

The leveling machine shown in Fig. 8 has the left and right punches 30 and 30 which grip the thick part 3 and the thin parts 2 and 2 of the multi-dimension strip 1 at the same time, thereby causing a tensile force in the longitudinal direction is applied, causing the multi-dimension strip 1 to undergo plastic deformation. The longer the distance between the left and right shapes 30 and 30 , the longer the multi-dimension strip, which can be leveled or straightened at a time. This contributes to productivity and facilitates control of the dies 30 and 30 for the same stretch. On the other hand, the gripping cylinders 34 and 36 and the stretching cylinder 35 must have a large capacity and the straightening machine therefore requires a large installation area. If the distance between the left and right punches 30 and 30 is small, the leveling machine is poor in productivity and cannot apply a uniform plastic deformation to the multi-dimension strip. For this reason, the distance between the left and right shapes 30 and 30 should be about 3 to 10 m.

The stamp 30 , which comes into contact with the multi-dimension strip 1 , can be formed from tool steel. It should have its contact surface coated with a urethane coating so that it does not damage the multi-dimension strip 1 . For the multi-dimension strip 11 , the stamp 30 a or 39 b should be used, as shown in FIG. 9B or 9C, which corresponds to the shape of the multi-dimension strip 11 and on the thick parts 13 and 13 and the thin part 12 is adjusted.

The amount of plastic deformation (or elongation) added to the multi-gauge strip 1 or 11 should be 0.05-1%. The amount of elongation is controlled by the distance ΔL over which the punch or shape moves, and the distance ΔL is approximately represented by equation (3) below.

ΔL = δ × LO (3)

(where LO is the distance between the left and right stamps and δ is the value (0.0005-0.001) of a plastic deformation)

The effect of a leveling treatment can be obtained by cutting a sample of the multi-measure strip 1 or 11 at five positions (e, b ₁ , b ₂ , c ₁ , c ₂ ) as described above (in section ( 3 ) Cutting method and measurements of a displacement), are confirmed. If a desired leveling effect is not produced, stretching as before or a greater stretch than before can be repeated until the amount of plastic deformation is less than 1% (based on the length before leveling) ,

The application or application of a tensile stress on the multi-fold strips 1 or 11 should preferably be carried out after the final step (or slitting) of the production; however, leveling may be followed by slitting. The leveled or balanced multi-dimension strip 1 or 11 can be slit before punching.

If the leveling or leveling is inadequate (less than 0.05%), the multi-dimension strip will result in problems when punching and mounting a lead frame (see FIG. 6) in the following steps. With excessive leveling or compensation (more than 1%), the multi-dimension strip is poor in its dimensional accuracy or has a residual tension in the longitudinal direction, which adversely affects the subsequent steps. Therefore, the corresponding amount of plastic deformation (or tensile straightening) should be 0.05-1%, preferably 0.1-0.6%, and more preferably 0.2-0.5%. A pull judge can be repeated two or more times until the total amount of judge or equalization is within the above value.

The invention will be described in more detail with reference to the following Examples are described, which are not intended to limit the scope limit the same.

example 1 Preparation of a multi-dimension strip

A blank or plate made of phosphorus-containing, deoxidized Copper (Cu-0.035P) was produced by semi-continuous casting. The Blank was rolled into a sheet, 2.1-3.2 mm thick and 600 mm wide, hot rolled and cold rolled. The sheet was cut into a strip 70 mm wide cut.

This strip was made into a multi-dimension strip (shown in Fig. 1) specified below in the following manner.

Width W: 65 mm, width D _{1 of} the central, thick part: 34 mm, thickness T _{1 of} the thin part: 0.4 mm, thickness T _{2 of} the thick part: 1.27 mm, angle of inclination α of the thick part: 10 ° (80 ° to the horizontal line). Production step: rough shaping or rough shaping (by pilger rolling), heat treatment or annealing (at 350-450 ° C for 2 hours), final rolling and slitting. The hardness of the thick and thin parts was regulated by changing the reduction in thickness during raw molding, the annealing temperature and the reduction in final molding. The multi-dimension strip thus obtained has a hardness (Hv) as shown in Table 1.

Preparation of samples

Three multi-measure strips (designated Nos. 1 to 3 in Table 1) were made prepared. Three pieces (about 300 mm long) of each of the multiple dimensions Strips taken. Each piece had its ends (about 50 mm) through one electric spark erosion machine (with a wire diameter of 0.5 mm) cut. A 200 mm long sample was thus obtained. Two marks were cut on the cut surface 2 mm each within the shoulder of the thick part made. The distance between the two marks was using a projector equipped with an X-Y actuator or - Movement table is provided, measured. Five markings were made on the cut surface (one at the center of the width, one at the border between the thick part and the thin part and one each 1 mm inside the edges or edges). Cuts (150 mm long) were made in the Longitudinal direction at the five marks using an electrical Spark machine or spark erosion machine (with a wire diameter of 0.5 mm).

Pressure punch test and measurement of a voltage or load

Each of the coils (No. 1 to 3) was in the lead frame or connecting comb punched using a punch press. The die cut product was in halved in the width direction. The halved frame was made into a length of 200 mm cut. The resulting sample was placed on a cross bend examined.

Each sample was examined for the distance of the marks and the inclination of the thin part using a projector (with a magnification of 100), which is equipped with an XY moving table. The distance of the markers was expressed as an average of three measurements. The sample was examined for A and B (shown in Fig. 5) using a projector equipped with an XY moving table. The inclination angle (θ) of the thin part was calculated from A and B. It is expressed in terms of an average or as an average of six measurements (three for right and left).

Table 1

results

Table 1 shows the results of measurements of the cross bend or Cross curvature and the tension or load of the halved lead frame. Sample Nos. 1 to 3 in Example 1 show a very small or undetectable visible cross bend and a very low tension (variation in the dimensions between two points on the shoulders and the inclination of the thin part). In contrast, Sample No. 4 in the comparative example shows a considerable one Cross bend (as well as a twist in the conductor). It shows a big one Stress due to an imbalance between the hardness of the thick part and the hardness of the thin part. (The result is a large variation in the Dimensions and a large angle of inclination.)

Example 2 Compensate or level or straighten

The multiple measure strips No. 1 to 4 were made by a train level machine or sheet straightening machine, which is specified below, for a certain Extent of a leveling or leveling performed. The resulting samples are designated as Nos. 1-2, 2-2, 3-3, 2-3 and 4-2.

• - Distance between stamps: 6 m
• - Width of the stamp: 85 mm
• - Length of the stamp: 200 mm

Preparation of samples and voltage measurement

The same procedure of Example 1 was repeated.  

Table 2

Results

Sample Nos. 1-2, 2-2 and 3-2 in Example 2 decreased in the Tension after cutting due to the leveling or straightening treatment development. In contrast, sample No. 4-2 in the comparative example has one greater stress value than samples in Example 1, though the voltage value drops even after balancing or leveling. to Sample No. 4-2 is also subject to a cross bend after being manufactured in a lead frame. Sample No. 2-3 in the comparative example shows a change (Contraction) in dimensions between two points on shoulders and one Increase in the angle of inclination of the thin part. This is because of the scale plastic deformation for tension leveling or straightening greater than 1% was.

Example 3 Preparation of a multi-dimension strip

A blank made of phosphorus-containing, deoxidized copper (Cu-0.035P) was produced by semi-continuous casting. The blank was in a ge wrapped sheet, 2.1-3.2 mm thick and 600 mm wide, hot rolled and cold rolled. The sheet was cut into a strip with a width of 110 mm or cut.  

This strip was shown in a multi-dimensional strip (in Fig. 3) specified below, made in the following manner.

Width W: 130 mm, width D _{3 of} the central, thin part: 36 mm, width D ₁ of each thick part: 34 mm, width D ₂ of each outer, thin part: 15.5 mm.

A wrapped sheet, 2.1-3.2 mm thick and 110 mm wide, was cut through Raw forms (by pilger rolling), heat treatment or annealing at 350-450 ° C formed for 2 hours, finish rolling and slitting. The multi-dimension strip varies in the hardness of the thick part and in the hardness of the thin part in Ab dependence on the reduction in thickness during rough forming, the annealing temperature and the reduction in thickness in finish rolling. Table 3 shows the hardness (Hv) of the Multi-dimension strips obtained in this way (No. 5 to 8).

Pressure punching test

Each of the coils (No. 5 to 8) was punched into lead frames using a punch press. The punched product was divided into four parts in the width direction. The divided frame was cut into a length of 200 mm. The resulting sample was examined for a cross bend or cross curvature (see FIGS . 3 and 5).

Cutting samples for a voltage measurement

Four multi-measure strips (designated Nos. 5 through 8 in Table 3) were prepared. Three pieces (about 300 mm long) were taken from each of the multi-size strips. Each piece had its ends cut (about 50 mm) by an electric spark erosion machine (with a wire diameter of 0.5 mm). A 200 mm long sample was thus obtained. Two marks were made on the cut surface, each outside the thick outer part (see Fig. 3). The distance between the two marks was measured using a projector equipped with an XY moving table (see Fig. 5). Five marks were made on the cut surface (one at the center of the width, one at the boundary between the outer thick part and the outer thin part and one each 1 mm inside the edges). Cuts (150 mm) were made in the longitudinal direction at the five marks using an electric spark machine (with a wire diameter of 0.5 mm).

Measurement of the tension of the cut sample

The same procedure as in Example 1 was repeated.

Table 3

results

Table. 3 shows the results of measurements of the cross bend and the Quartered lead frame tension. Sample Nos. 5 to 7 in Example 3 show a very slight or undetectable cross bend and a very ge rings tension (variation in dimensions between two points at the outer shoulders and inclination of the thin part). In contrast, shows Sample No. 8 in the comparative example due to a remarkable cross bend an imbalance between the hardness of the thick part and the hardness of the thin part. (The result is a large variation in dimensions and one large angle of inclination.)  

Example 4 Compensate or level

The multi-dimension strips No. 5 to 8 were replaced by a tension compensation or sheet straightening machine, which is specified below, for a specific one Extent of an equalization or straightening carried out. The resulting Samples are designated Nos. 5-2, 6-2, 7-2, 6-3 and 8-2.

• - Distance between stamps: 6 m
• - Width of the stamp: 120 mm
• - Length of the stamp: 200 mm

Preparation of samples and measurement of a cross bend and tension

The same procedure as in Example 1 was repeated to prepare samples deliver and measure a cross bend or transverse curvature and tension.

Table 4

results

Sample Nos. 5-2, 6-2 and 7-2 in Example 4 decreased in the Tension after cutting due to the leveling or compensation action. In contrast, Sample No. 8-2 in the comparative example has one greater value of stress than Sample Nos. 5 to 7 in Example 3, though  the value of the tension drops even after balancing or straightening. The Sample No. 6-3 in the comparative example shows a change (contraction) in dimensions solutions between two points on the shoulders and an increase in the Tilt angle of the thin part. This is because the extent of a plastic deformation for tension leveling was greater than 1%.

Example 5 Preparation of a multi-dimension strip

A blank (150 mm thick, 500 mm wide and 4000 mm long) from C19210 (Cu-0.1Fe-0.03P) was produced by semi-continuous casting. The The blank was hot rolled in a hot coil with a thickness of 15 mm. The hot coil was cold rolled into a 2.6 mm thick sheet, which follows was subjected to heat treatment at 500 ° C for 2 hours. The heat-treated coil was cold-rolled in a 2.0 mm thick sheet. This Sheet metal was slit around a 50 mm wide, flat strip for more to form strips.

The flat strip was made into a multi-dimension strip by pilger rolling and rolling with a grooved roll and a flat roll. The intermediate strip was annealed or heat treated continuously at a rate or speed of 13 m / s in an annealing furnace (at a temperature of 725 ° C. and with a 20 m long heating zone). The heat treated strip was subjected to finish rolling with a grooved roller and a flat roller. In this way, the desired multi-dimension strip was obtained, which is specified below.
Thick part thickness: 1.25mm
Thin part thickness: 0.40 mm
Thick part width: 29 mm
Width of the thin part: 28 mm
Overall width: 75 mm
Side wall angle of the thick part: 15 °

The intermediate multi-dimension strip was made under different loading conditions rolled so that the thin part varies in thickness. A remuneration or  Annealing was carried out under various conditions so that the end varies according to softening. A finish rolling was done under different Conditions performed so that the extent of machining hardening varies and the hardness of the thin part varies. Table 5 shows the thickness of the the thick part and the thin part of the intermediate multi-dimension strip and the finished multi-dimension strip.

Table 5

Hardness measurement

The multi-dimension strip produced as mentioned above was made on the Hardness (Hv) of the thin part and the hardness of the thick part were examined. The Re results are shown in Table 6. In this example, the thin part and the thick part has the same hardness.

Example No. 10 in the comparative example is characterized in that the Hardness of the thin part is much greater than the hardness of the thick part. This is the half because the reduction in thickness when rolling the intermediate multiple dimension Streak is small, the extent of softening when glowing or Heat treatment is small and the reduction in thickness in finish rolling is large (which results in a large machining hardening).

Example No. 11 in the comparative example is characterized in that the Hardness of the thin part is less than that of the thick part. This is because the Large reduction in thickness when rolling the intermediate multi-size strip is, the degree of softening upon annealing is large and the reduction in thickness in finish rolling is small (which in one less machining hardening results).  

Table 6

results

The multi-dimension strips in the examples and comparative examples were in lead frames or combs by a continuous stem peln or punching processed. The multiple measure strips in Example 5 showed no problems with stamping or punching and the resulting wire frame men had no cross-bend or cross-curvature. In contrast to In the comparative example, the multi-dimension strips blocked the punched or The stamp shape and the punched lead frame (sample No. 10) suffered from a cross bend and twist. This is due to a large residual voltage. The Multi-dimension strips (sample No. 11) caused no problems when punching, however, the punched lead frames suffered from a slight cross bend.

According to the present invention it is possible to use multi-dimension strips generate a small amount of residual stress (load) exhibit. Such multi-dimension strips contribute to productivity and yield when pressing, assembling a transistor and assembling a connection because it does not suffer from deformation, such as elongation, Suffer from contraction, curvature, cross-bending or twisting.

The multi-dimension strip of the present invention is rolled so that the stress distribution varies from the thin part to the thick part. Therefore the thin part has a hardness of H1 and the thick part has a hardness from H2 so that the ratio of H1 / H2 is in the range of 0.9 to 1.5. This value indicates that the multi-dimension strip is a suitable or appropriately distributed residual voltage, and this value allows one  also to judge whether the residual stress is distributed accordingly or evenly is or not.

According to the present invention, the multi-dimension strip is through Measure the displacement between two points (which occurs when cuts in the sample as specified) and by measuring the Nei angle of the thin part is assessed or evaluated. The results of Measurements allow one to judge whether the voltage is corresponding or is evenly distributed at the position where the residual stress becomes one Accumulation tends. This allows one to judge whether the given one Multi-dimension strips are suitable for further processing.

According to the present invention, the multi-dimension strip becomes one Tensile stress imparted, which plastic deformation in the range of 0.05 to 1% in the longitudinal direction. The so applied or on applied tension levels or aligns the multi-dimension strip, which has a residual stress, and therefore minimizes a residual stress, which has accumulated during manufacture.

Claims (6)

1. Multi-dimension strips with a cross section, which has one or more thin parts and thick parts, which are formed by rolling over its width, the cross section being uniformly continuous in the longitudinal direction, characterized in that the thin part has a hardness of H1 and the thick part has a hardness of H2, the ratio of H1 / H2 being between 0.9 and 1.15. 2. Multi-dimension strip according to claim 1, wherein the thick part only in that Center of width is formed and the thin parts on both sides of the thick part are formed and in which the cross section is uniform such that if the multi-dimension strip is 1.2 to 5 times longer in its longitudinal direction its width at five positions, one at the center of the width, one at each Border between the thin part and the thick part and one at each Edge or the edge of the thin part to be cut or slit cut, the dimensional deviation between the two points, which are symmetrical to each other relative to the center of the width, in the cut Surface is less than 0.15 mm at the end where cutting begins. 3. Multi-dimension strip according to claim 1, wherein two thick parts sym are metric, with a thin part in the center of the width is formed and thin parts on both edges or edges outside the thick parts are formed, and wherein the cross section is uniform such that if the multi-dimension strip is 1.2 to 5 times longer in its longitudinal direction its width at five positions, one at the center of the width, one at each Outer boundary between the thin part and the thick part and one each the edge of the thin part to be cut, which Dimensional deviation between the two points, which is symmetrical to the Center of width are less than 0.15 mm in the cut surface the end is where the cutting begins.   4. Multi-dimension strip according to claim 1, wherein the thick part only in that Center of the width is formed and the thin parts on both edges or Edges are formed and in which the cross section is uniform such that if the multi-dimension strip is 1.2 to 5 times longer in its longitudinal direction its width at five positions, one at the center of the width, one at each Border between the thin part and the thick part and one at each The edge or the edge of the thin part to be slit is cut, the Nei angle of the cut, thin part less than 4 ° to the horizontal Baseline at the end is where the cutting begins. 5. Multi-dimension strip according to claim 1, wherein two thick parts sym are metric, with a thin part in or at the center of the Is formed wide and thin parts on both edges or edges outside the thick parts are formed, and wherein the cross section is uniformly such that if the multi-dimension strip in its longitudinal direction over the 1,2- to 5- times its width at five positions, one at the center of the width, one at a time the outer boundary between the thin part and the thick part and one each is cut at the edge or the edge of the thin part to be cut, the angle of inclination of the cut thin part is less than 4 ° to the horizon tal baseline at the end is where the cutting begins. 6. Multi-dimension strips with a cross-section, which one or more has thin parts and thick parts, which by rolling across its width are formed, the cross section being uniformly continuous or is continuous in the longitudinal direction, with the multi-dimension streak after rolling by applying an elongation or tension tension is balanced or leveled, which is a plastic deformation corresponding to 0.05 to 1% of the elongation or elongation in the longitudinal direction equivalent.