CN107683050A - Housing, mobile terminal and manufacturing method of housing - Google Patents

Abstract

The invention relates to the field of electronic equipment, and discloses a shell which comprises a metal substrate and a first plastic body, wherein the metal substrate comprises a first surface and a second surface which are oppositely arranged, a groove is formed in the first surface, at least two micro-seams are formed in the second surface, the at least two micro-seams are communicated with the groove, and the first plastic body is filled in the at least two micro-seams and the groove. The groove on the first surface is communicated with the at least two micro-seams on the second surface, so that the first plastic bodies filled in the micro-seams and the groove are communicated into a whole in the metal matrix, and the integral rigidity of the micro-seam structure is improved. The invention also provides a mobile terminal and a shell manufacturing method.

Description

Housing, mobile terminal and manufacturing method of housing

technical field

The invention relates to the field of electronic equipment, in particular to a casing, a mobile terminal and a method for manufacturing the casing.

Background technique

Nowadays, in the mobile terminal market, all-metal shells are more and more favored by consumers. However, although mobile terminals with all-metal shells are beautiful, for many mobile terminals with antennas that need to receive or transmit radio frequency signals, the shielding effect of the all-metal shell on radio frequency signals has become an obstacle to its application as a shell .

Mobile terminal manufacturers have made a lot of optimizations and improvements to address this defect in the existing designs. The more common improvement method is to process a gap through the metal shell on the back of the metal mobile phone with a CNC machine tool, and inject plastic into the gap. Shielding material, forming a clear area for the passage of radio frequency signals. However, non-shielding materials such as plastics are filled on the metal shell. The hardness of the material is lower than that of metal, and the rate of thermal expansion and contraction is also different from that of metal. Therefore, scratches or cracks are prone to appear in the gaps of the metal shell during long-term use. On the other hand, the overall consistency and touch of the mobile terminal shell are also affected to a certain extent.

Contents of the invention

The purpose of the present invention is to provide a housing, a mobile terminal and a manufacturing method of the housing, which can effectively improve the overall rigidity and appearance consistency of the gap clearance area.

In order to solve the above technical problems, the embodiments of the present invention provide the following solutions:

In one aspect, a casing is provided, which includes a metal base and a first plastic body, the metal base includes a first surface and a second surface opposite to each other, the first surface is provided with grooves, and the second surfaces are provided with each other At least two micro-slits at intervals, the at least two micro-slits both penetrate to the groove, the first plastic body is filled in the at least two micro-slits and the groove, and the first plastic The body adopts non-signal shielding material.

In another aspect, a mobile terminal is also provided, including the above casing.

In another aspect, there is also provided a shell manufacturing method, comprising the following steps:

machining grooves on the first side of the metal substrate;

filling the groove with a second plastic body;

At least two micro-slits are processed on the metal base, the metal base also includes a second surface opposite to the first surface, and the at least two micro-slits penetrate from the second surface to the concave groove;

removing the second plastic body in the groove;

filling the first plastic body in the at least two micro-slits and the groove; and

curing the first plastic body.

In the case provided by the embodiment of the present invention, the micro-slits are arranged side by side in the clearance area, and the micro-slits are connected through the grooves, and the independent elongated thin-layer structure non-shielding materials Connected as a whole, with the strip-shaped metal support formed between the adjacent micro-slits, the non-shielding material in the clearance area has better connectivity and rigidity compared with the existing design, and at the same time during the processing The provision of the transitional second plastic body greatly improves the manufacturability of the metal substrate after the grooves are formed, helps reduce the difficulty of micro-slit processing, and improves the yield. The micro-slits of the mobile terminal provided by the embodiment of the present invention support each other because they communicate with each other, which ensures the rigidity of the metal shell.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings that need to be used in the implementation. Obviously, the drawings in the following description are some implementations of the present invention, which are common to those skilled in the art. As far as the skilled person is concerned, other drawings can also be obtained based on these drawings on the premise of not paying creative work.

Fig. 1 is the schematic diagram of housing section of the present invention;

Fig. 2 is a schematic diagram of the appearance of the housing of the present invention;

Fig. 3 is a schematic diagram of the appearance of the terminal of the present invention;

Fig. 4 is a schematic flow chart of the first embodiment of the method of the present invention;

Fig. 5 is the schematic diagram of the second injection molded body in the method embodiment process of the present invention;

Fig. 6 is a schematic diagram of filling the first injection molded body during the embodiment of the method of the present invention;

Fig. 7 is a schematic flowchart of the second embodiment of the method of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the description of the embodiments of the present invention, it should be understood that the orientation or positional relationship indicated by the term "thickness" is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than implying Or an indication that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the invention.

Please refer to FIG. 1 , which is a cross-sectional view of a housing 200 according to an embodiment of the present invention. A metal base 100 is provided, and a first surface 01 and a second surface 02 are oppositely arranged on the metal base 100, and a groove is provided on the first surface 01. 11. The second surface 02 is provided with at least two micro-slits 21 arranged side by side and spaced apart from each other. Both of the at least two micro-slits 21 penetrate the metal base 100 to the groove 11. The micro-slits 21 and the groove 11 are all filled with the first plastic body 001, and the first plastic body 001 is made of non-signal shielding material, usually plastic glue.

Usually, the slit directly opened on the housing 200 is wide, and the micro slits 21 are set side by side to form a headroom structure of "metal-micro-slit material-metal" staggered arrangement, which can better avoid a wider headroom The area affects the strength of the metal case, as well as the appearance consistency and feel, while ensuring sufficient headroom area. However, since the micro-slit 21 must completely penetrate the housing 200, the non-shielding material filled in the micro-slit 21 has an elongated thin-layer structure, and multiple rows of elongated thin-layer structures are arranged side by side, which is not conducive to The rigidity control of the metal base 100 also imposes higher technological requirements on the machining accuracy and surface roughness of each of the micro-slits 21 , which easily affects the yield of products.

It can be understood that when each of the micro-slits 21 communicates with the groove 11, because the first plastic body 001 filled in the groove and the first plastic body 001 filled in each of the micro-slits 21 A plastic body 001 is connected as a whole, the overall structural stability of the first plastic body 001 has been greatly improved, and at the same time, the stable first plastic body 001 also improves the metal base 100, and even the The overall rigidity and structural stability of the casing 200 , while the long metal parts interlaced between the micro-slits 21 , that is, the frame bars 22 also maintain the integrity of the casing 200 in appearance and feel.

Preferably, the metal base 100 is cut by means of laser cutting, and the slit width of the micro-slits 21 is processed to be less than 0.3 mm.

In this embodiment, a frame bar 22 extending along the first direction is formed between two adjacent micro-slits 21. FIG. 1 is a cross-sectional view perpendicular to the first direction. The first plastic body 001 Preferably, it is injected from the first surface 01, that is, the groove 11, and starts to fill from the second surface 02, that is, the micro-slit 21. The injected plastic first fills the micro-slit 21 and then fills up all of the micro-slits. The groove 11. The reason for such setting is that the gaps of the micro-slits 21 are too small, and the filling process is more complicated. Therefore, the opening width of the groove 11 on the first surface 01 should be greater than the opening width of the micro-slit 21 on the second surface 02, so as to ensure that the injection port of the plastic is larger than the molding port. During the injection process, it is in an aggregated state to avoid defects such as air bubbles due to uneven diffusion of plastic, which will damage the quality of injection molding and the quality of the final molding of the first injection molding body 001 . The opening width of the micro-slits 21 on the second surface 02 in this embodiment is understood as the distance between two side walls of the plurality of micro-slits 21 arranged side by side that are farthest from each other.

Further, on a cross section perpendicular to the first direction, the groove 11 is configured as a trapezoid, and the long side of the trapezoid is the boundary line between the groove 11 and the first surface 01, namely The short side of the trapezoid is the interface between the groove 11 and the micro-slit 21, such a setting can further use the side wall of the groove 11 to guide the plastic glue to continuously gather inward during the filling process, improving the The quality of the filling. On the other hand, because the micro-slit 21 is cut by laser, it usually appears as a straight face on this section, and the opening width of the micro-slit 21 is the micro-slit at the interface between the micro-slit 21 and the groove 11. Maximum width of seam 21. The trapezoidal setting can ensure that the side wall of the groove 11 is wider than the overall width of the plurality of micro-slits 21, avoiding the inverted taper and other shapes that are not conducive to the molding of plastic glue during the filling process, and ensuring the filling quality.

One embodiment, as can be seen in this section, because the micro-slits 21 are vertical through holes, the position where each of the micro-slits 21 and the groove 11 intersects, that is, the frame bar 22 faces The periphery of the end surface of the groove 11 will form a right angle, and after the first injection molded body 001 is formed, the first injection molded body 001 will also form a corresponding right angle shape. This right-angled shape is not conducive to the stress release of the first injection molded body 001 during the injection molding process. After long-term use, it is easier to form stress concentration points, cracks, etc., which eventually lead to the appearance and structural stability of the first injection molded body 001. Therefore, rounding the right angles around the end surface of the groove 22 can further improve the structural stability of the first injection molded body 001 .

In the embodiment of the present invention, the housing 200 is made of the metal base 100 (see FIG. 2 ), and the housing 200 may be a back cover or a back cover of a mobile terminal (see FIG. 3 ). The mobile terminal involved in the embodiment of the present invention can be any device with communication and storage functions, such as: tablet computer, mobile phone, e-reader, remote controller, personal computer (PersonalComputer, PC), notebook computer, vehicle-mounted equipment, network TV, Smart devices with network functions such as wearable devices. Because the mobile terminal uses the casing of the invention, it has better appearance consistency and structural stability while realizing radio frequency signal transmission and reception.

Please refer to FIG. 4 , which is a schematic flow chart of the manufacturing method of the housing provided by the embodiment of the present invention. The method of the embodiment of the present invention may include the following steps S11 to S16:

S11: provide a metal substrate 100, the metal substrate 100 includes a second surface 02 and a first surface 01 oppositely arranged, and a groove 11 is processed on the first surface 01;

Specifically, the metal base 100 may be the shell 200 of the mobile terminal, that is, the back cover or back cover. The groove 11 processed on the first surface 01 cooperates with the micro-slit 21 to be processed later, so the shape of the groove 11 corresponds to the shape of the micro-slit 21 to be formed .

S12: filling the second plastic body 002 in the groove 11 by injection molding;

Specifically, referring to FIG. 5 , for injection molding filling in the groove 11 , the metal base 100 is placed on the positioning jig 400 of the dispenser 300 , because the second plastic body 002 belongs to the process transition As for the filling material, the main focus is that the second plastic body 002 should cover the bottom surface of the groove 11 as much as possible, so as to facilitate the subsequent processing of the micro-slit 21 . Because the second plastic body 002 is a process transition filler, when the injection molding of the second plastic body 002 is completed, partly higher than the first surface 01, or partly lower than the first surface 01, the subsequent The process has little impact. It can be understood that the second plastic body 002 may be an insulating layer in the shell processing process.

S13: Processing at least two micro-slits 21 on the second surface 02 facing the groove 11, the processing depths of the at least two micro-slits 21 all penetrate the metal substrate 100 and reach the first Two plastic body 002;

Specifically, the micro-slits 21 may be processed by cutting the metal base 100 by means of laser cutting. It can be understood that the slit width of the micro slit 21 is less than 0.3 mm, and the smaller the micro slit 21 is, the more applicable the laser cutting method is. Certainly, in other embodiments, the slit width of the micro-slits 21 may be greater than or equal to 0.3 mm. Due to the filling of the second plastic body 002, the part of the groove 11 can provide a certain support for the processing of the micro-slit 21, and enhance the self-rigidity of the micro-slit 21 during processing, so that the micro-slit 21 is not easy to be twisted, tilted and other deformations during processing, which is conducive to improving the processing performance of the micro-slit 21 and reducing processing difficulty.

S14: process and remove the second plastic body 002 in the groove 11, so that the at least two micro-slits 21 communicate through the groove 11;

Specifically, because the depth of the at least two micro-slits 21 has reached from the second surface 02 into the second plastic body 002, after the processing and cleaning of the plastic body 001 is completed, the at least Two micro-slits 21 have penetrated the bottom surface of the groove 11, and there are at least two through-paths of micro-slits 21 between the second surface 02 and the first surface 01, forming the clearance required by the antenna district structure.

S15: Injection-filling the first plastic body 001 in the at least two micro-slits 21 and the groove 11;

Specifically, as shown in FIG. 6 , for injection molding in the at least two micro-slits 21 and the groove 11 , it is necessary to set a stopper 420 at the other end of the plastic injection port to prevent the plastic from continuously falling through the through hole. On the side of the injection port, the final molding height should be controlled. It can be understood that the finally formed first plastic body 001 should be flush with the second surface 02 and the first surface 01 , at least not lower than the second surface 02 or the first surface 01 .

S16: Curing the first plastic body 001.

Specifically, after the first plastic body 001 is solidified, the filling of the micro-slits 21 is completed, and there are no more gaps in the entire metal matrix 100, and the second surface 02 and the first surface 01 belong to smooth.

In the manufacturing method of the metal matrix shell provided by the embodiment of the present invention, the plastic bodies in the juxtaposed elongated micro-slits are connected as a whole through the first plastic body in the groove area, which is more helpful Due to the structural stability of the plastic body in each micro-slit, the appearance consistency and reliability of the shell can be improved after injection molding is completed. On the other hand, the second plastic body, as a transitional filling material in the process, ensures the rigidity of the groove, provides strong support during the processing of the micro-slit, ensures the processing quality of the micro-slit, and reduces the The processing difficulty of the micro-slits.

Please refer to FIG. 7 , which is a schematic flowchart of a shell manufacturing method provided by the second embodiment of the present invention. The specific method may include the following steps S21 to S29:

S21. Provide a metal base 100, said metal base includes a second surface 02 and a first surface 01 oppositely arranged, and a groove 11 is processed on said first surface 01;

Specifically, the metal base 100 may be the shell 200 of the mobile terminal, that is, the back cover or back cover. The groove 11 processed on the first surface 01 cooperates with the micro-slit 21 to be processed later, so the shape of the groove 11 corresponds to the shape of the micro-slit 21 to be formed , on a cross section perpendicular to the first direction, the opening width of the groove 11 on the first surface 01 should not be smaller than the width of the micro-slit 21 to be formed.

Obviously, numerical control machine tools can be used to process the groove 11, which can obtain better processing quality. In order to form the width of the groove 11 not less than the width of the micro-slit 21 to be formed, it can be controlled by milling. There are two specific implementation methods:

S211. When the milling cutter vertically processes the groove 11, a conical milling cutter is used. The lateral minimum width of the conical milling cutter is at the cutter head, and the farther the cutter body is from the cutter head, the larger the lateral width is. One way of expression is that the diameter of the tapered milling cutter decreases from the cutter body to the cutter head, at this time, the shape of the groove 11 can be formed;

S212. When the milling cutter obliquely processes the groove 11, a cylindrical milling cutter can be used. At this time, the cylindrical milling cutter should be arranged obliquely relative to the metal base 100, and the cutter head is biased to the inside of the groove, and the blade body Offset to the outside of the groove. It can be understood that such oblique processing is usually implemented by obliquely clamping the base body 100 on a CNC milling machine.

S22. Injection molding and filling the second plastic body 002 in the groove 11;

Specifically, for the injection molding filling in the groove 11, the metal base 100 is placed on the positioning jig of the dispenser, the first surface 01 is upward, and the dispensing head of the dispenser is facing the Groove 11, because the second plastic body 002 is a process transition filler, the main focus is that the second plastic body 002 should be as close as possible to the bottom surface of the groove 11, so that the subsequent micro-slits 21 processing. Because the second plastic body 002 is a process transition filler, when the injection molding of the second plastic body 002 is completed, partly higher than the first surface 01, or partly lower than the first surface 01, the subsequent The process has little impact.

S23. Processing at least two micro-slits 21 on the second surface 02 facing the groove 11, the processing depths of the at least two micro-slits 21 all penetrate the metal base 100 and reach the first Two plastic body 002;

Specifically, the micro-slits 21 may be processed by cutting the metal base 100 by means of laser cutting. It can be understood that the slit width of the micro slit 21 is less than 0.3 mm, and the smaller the micro slit 21 is, the more applicable the laser cutting method is. Certainly, in other embodiments, the slit width of the micro-slits 21 may be greater than or equal to 0.3 mm. Due to the filling of the second plastic body 002, the part of the groove 11 can provide a certain support for the processing of the micro-slit 21, and enhance the self-rigidity of the micro-slit 21 during processing, so that the micro-slit 21 is not easy to be twisted, tilted and other deformations during processing, which is conducive to improving the processing performance of the micro-slit 21 and reducing processing difficulty. Obviously, numerically controlled machine tools can also be used to process the micro-slits 21 to obtain better surface quality.

S24. Processing and removing the second plastic body 002 in the groove 11, so that the at least two micro-slits 21 communicate through the groove 11;

Specifically, because the depth of the at least two micro-slits 21 has reached from the second surface 02 into the second plastic body 002, after the processing and cleaning of the plastic body 001 is completed, the at least Two micro-slits 21 have penetrated the bottom surface of the groove 11, and there are at least two through-paths of micro-slits 21 between the second surface 02 and the first surface 01, forming the clearance required by the antenna district structure. Apparently, the second plastic body 002 can be removed by a numerical control machine tool, and a better removal effect can be obtained.

S25. Rounding the right angle on the circumference of the frame bar 22 towards the end surface of the groove 11;

Specifically, the right-angle portion can be rounded with a forming tool, which is a relatively mature process, and its purpose is to form rounded corners on the housing 200 and eliminate local stress concentration.

In addition, after the fillet processing is completed, there may be burrs or dirt on the inside, outside or peripheral surface of the micro-slit 21 and the groove 11. In order to facilitate filling of the micro-slit 21, the metal The surface of the substrate 100 is treated.

S26. Injection molding and filling the first plastic body 001 in the at least two micro-slits 21 and the groove 11;

Specifically, as shown in FIG. 6 , the injection molding in the at least two micro-slits 21 is preferably arranged before the injection molding action of the groove 11 . Because the optimal injection molding condition for the micro-slit 21 is when both ends of the micro-slit 21 are in the passage. If the groove 11 is injected first, one end of the micro-slit 21 has been filled with the first plastic body 001, and then filling the narrow micro-slit 21 will be relatively difficult to control the generation of air bubbles, etc. Disadvantages. It can be understood that the first plastic body 001 should be flush with the second surface 02 and the first surface 01 , at least not lower than the second surface 02 or the first surface 01 .

Specifically, when filling the micro-slit 21 by injection molding, the base body 100 is placed between the glue dispenser 300 and the suction jig 400, the second surface 02 faces the suction jig 400, and the The first surface 01 is facing the dispensing head 310 of the dispenser 300, and the dispenser 300 dispenses at least one of the micro-slits 21, while the suction jig 400 controls the micro-slits 21 Inhale the plastic glue in it. Specifically, the substrate 100 is placed on the positioning jig 410 of the dispenser 300 to ensure the alignment and tolerance between the dispensing head 310 of the dispenser 300 and the micro-slit 21, and at the same time A plurality of through holes 401 are opened on the positioning jig 410 to form the suction jig 400. When the base 100 is placed on the positioning jig 410, it can be positioned at all positions of the dispenser 300. Between the dispensing head 310 and the suction jig 400, the dispensing head 310 dispenses glue to the micro-slit 21, and the plurality of through holes 401 on the suction jig 400 correspond to The plastic glue in the micro-slit 21 is sucked to form a negative pressure between the base 100 and the suction jig 400, so that the plastic glue in the micro-slit 21 has fluidity, and can flow from the The first surface 01 flows to the second surface 02 and is evenly filled in the micro-slits 21 to realize complete filling of the plastic glue in the micro-slits 21 .

Specifically, on the suction jig 400, a retaining wall 420 is provided at the gap of the micro-slit 21, and the retaining wall 420 has a plurality of through holes 401, which can correspond to the first plastic The forming and positioning of the body 001 on the end face of the micro-slit 21.

S27. Curing the first plastic body 001;

Specifically, after the first plastic body 001 is solidified, the filling of the micro-slits 21 is completed, and there are no more gaps in the entire metal matrix 100, and the second surface 02 and the first surface 01 belong to smooth.

S28. Using a CNC machine tool to remove the part of the first plastic body 001 overflowing the second surface 02 and the first surface 01;

Specifically, after the first plastic body 001 is filled and cured, part of it may overflow the second surface 02 or the first surface 01, or stick to the surface of the metal base 100, affecting the metal base 100. 100 has an overall appearance, so the plastic on the metal base 100 is removed by using a CNC machine tool. Preferably, the plastic on the surface of the metal base 100 is completely removed by taking out a certain thickness of metal material from the metal base 100 by a numerical control machine tool.

S29. Perform at least one surface treatment of surface polishing, sand blasting, or anodic oxidation on the metal base 100 .

Specifically, at least one surface treatment of surface polishing, sand blasting or anodic oxidation is performed on the metal base 100 . Wherein, the surface treatment of the metal base 100 is carried out by means of anodic oxidation, so as to further improve the appearance consistency of the metal base 100 .

The modules or units of the embodiments of the present invention can be combined or split according to actual needs.

The above is the implementation manner of the embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the embodiment of the present invention, some improvements and modifications can also be made. These improvements and modifications are also It is regarded as the protection scope of the present invention.

Claims (14)

1. a kind of housing, it is characterised in that including metallic matrix and the first plastic body, the metallic matrix includes what is be oppositely arranged First face and the second face, first face open up groove, and second face opens up at least two slits being spaced, it is described extremely Few two slits are through to the groove, first plastic body be filled in it is described at least in two slits and the groove, First plastic body uses non-signal shielding material.

2. housing as claimed in claim 1, it is characterised in that formed between two adjacent slits and prolonged in the first direction The moulding stretched, on the cross section of the first direction, the groove has the first opening on first face Width, there is the second A/F on second face between the two side of at least two slit lie farthest aways, it is described First A/F is more than or equal to second A/F.

3. housing as claimed in claim 2, it is characterised in that described recessed on the cross section of the first direction Groove is trapezoidal, and the trapezoidal long side is the groove and the boundary line in first face.

4. housing as claimed in claim 1, it is characterised in that formed between two adjacent slits and prolonged in the first direction The moulding stretched, the end face periphery of every moulding towards the groove are disposed as round-corner transition.

5. a kind of mobile terminal, it is characterised in that including the housing as described in Claims 1 to 4 any one.

6. a kind of method for producing shell, it is characterised in that comprise the following steps：

Groove is processed on the first face of metallic matrix；

The second plastic body is filled in the groove；

Process at least two slits on the metallic matrix, the metallic matrix also includes relative with first face the Two faces, at least two slits are through to the groove from second face；

Remove second plastic body in the groove；

At least the first plastic body is filled described in two slits and the groove；And

Solidify first plastic body.

7. method for producing shell as claimed in claim 6, it is characterised in that process institute with taper mill on Digit Control Machine Tool State groove, the taper mill on the direction from blade to cutter head diameter successively decrease.

8. method for producing shell as claimed in claim 6, it is characterised in that processed on Digit Control Machine Tool with cylindrical milling cutter The groove, the cutter head of the cylindrical milling cutter are inclined to the inside of the groove, and blade is inclined to the outside of the groove.

9. method for producing shell as claimed in claim 6, it is characterised in that form metal between two adjacent slits Moulding, before first plastic body is filled, fillet processing is carried out towards the end face periphery of the groove to the moulding.

10. method for producing shell as claimed in claim 6, it is characterised in that the fill method of first plastic body includes：

The dispensing completed by dispensing action at least two slits and the groove acts, to form the institute of one State the first plastic body.

11. method for producing shell as claimed in claim 10, it is characterised in that the dispensing action includes：

The metallic matrix is positioned between point gum machine and Suction jig；

The point gum machine carries out dispensing at least two slits, and the Suction jig is to the modeling at least two slits Glue glue carries out air-breathing；And

The point gum machine carries out dispensing to the groove.

12. method for producing shell as claimed in claim 11, it is characterised in that by the metallic matrix be positioned over point gum machine and When between Suction jig, the Glue dripping head of point gum machine described in the face of first face, described second facing to the Suction jig.

13. method for producing shell as claimed in claim 6, it is characterised in that after the first plastic body solidification, utilize numerical control Lathe removes the part that first plastic body overflows second face and first face.

14. method for producing shell as claimed in claim 13, it is characterised in that overflow part removing first plastic body Afterwards, at least one surface treatment of surface polishing, sandblasting or anodic oxidation is carried out to second face of the metallic matrix.