JP2003081331A - Embossing tape for electronic parts, its manufacturing method and pocket forming die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an embossing tape for electronic parts capable of surely preventing a lead wire from being deformed while the electronic parts are moved within a package in a lateral direction during transportation or the like. SOLUTION: There is provided an embossing tape 1 for electronic parts having a pocket 3 for storing electronic parts and a rib 9 raised from a bottom surface 5 of the pocket 3 so as to hold the electronic parts 4 stored in the pocket. The rib 9 is inclined against the bottom surface 5 of the pocket 3 in the same direction as that of a lower side surface 12 of the package 11 of the electronic parts 4 and more gradually than the lower side surface 12 and the lower edge of the electronic parts 4 is received in the rib 9 without any clearance at all.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an embossed tape for electronic parts, which is used for taping electronic parts in which thin leads led out from the side surface of a package such as a QFP type electronic part are bent downward, and a method for manufacturing the same. , And an embossed tape for an electronic component, which is capable of preventing lateral deformation of the electronic component in a pocket for housing the electronic component and preventing deformation of leads of the electronic component, and a manufacturing method thereof. The present invention relates to a method and a pocket forming mold.

[0002]

2. Description of the Related Art An embossed tape for electronic parts is a synthetic resin tape for supporting electronic parts at a constant interval for mounting QFP type electronic parts or the like on a printed wiring board. Recesses called pockets for accommodating electronic components are formed at predetermined intervals in the longitudinal direction.

Specifically, for example, Japanese Unexamined Patent Publication No. 7-21539
As described in Japanese Unexamined Patent Publication (Kokai) No. 0, in order to prevent lateral movement of electronic parts, for example, a part of the bottom surface of the pocket is incised and bent to form an opening and these openings. Locking means including a protrusion (hereinafter referred to as a rib) formed along the portion is provided.

This rib is bent at a right angle to the bottom surface, or is bent in multiple steps so that the upper part is at a right angle to the bottom surface. There is a slight gap between it and the package.

[0005]

Therefore, although the electronic components are laterally moved, the ribs are elastically deformed by the impact of the package colliding with the ribs, and the leads are located on the side opposite to the moving direction. The rib may be impacted and deformed, resulting in a defective product in which the surface of the printed wiring board, which requires an accuracy of the order of several microns to several tens of microns, is displaced with respect to the land.

In order to solve this problem, the gap between the rib and the package should be made ultrafine on the order of several microns. Such an ultrafine gap makes it possible to hot press or cold press the pocket. Since it is smaller than the error range of heat shrinkage that occurs due to the press forming, it cannot be formed accurately.

The embossed tape for electronic parts according to the present invention (hereinafter referred to as "article of the present invention") solves the problems of the prior art, reliably prevents lateral movement of electronic parts, and prevents deformation of lead wires. It is an object of the present invention to provide an embossed tape for electronic parts, which is made possible.

By the way, in the conventional method for manufacturing an embossed tape for electronic parts, the rib is formed through at least two steps of incising the bottom surface of the pocket or punching the peripheral edge of the rib and then bending the rib. However, there is a problem that the process time as a whole is long and the cost is high. Moreover, since the precise pocket cannot be formed as described above, the lead wire of the electronic component housed in the pocket is deformed. There is a problem that there is.

The method for producing an embossed tape for electronic parts according to the present invention (hereinafter referred to as the method of the present invention) solves these problems of the prior art and can produce an embossed tape for electronic parts at low cost in a short time. Moreover, it is an object of the present invention to provide a method for manufacturing an embossed tape for electronic parts, which can prevent the deformation of the lead wire of the electronic part housed in the pocket by using the manufactured embossed tape for electronic parts.

Further, there are two types of molds used in the conventional method for manufacturing an embossed tape for electronic parts: a mold for cutting or punching a part of the bottom surface of a pocket, and a mold for bending ribs. However, there is a problem that the die cost becomes high.

The pocket forming die according to the present invention (hereinafter,
The present invention is called a mold. ) Makes it possible to form ribs at the same time as forming pockets, so that an embossed tape for electronic parts can be manufactured in a short time and at low cost, and if the manufactured embossed tape for electronic parts is used, the electronic parts stored in the pockets can be manufactured. It is an object of the present invention to provide a pocket mold capable of preventing the lead wire from being deformed.

[0012]

The article of the present invention is for an electronic component having a pocket for storing an electronic component and a rib raised from the bottom surface of the pocket so as to sandwich the electronic component stored in the pocket. In order to achieve this object, the embossed tape employs a technical means characterized in that the rib is inclined with respect to the bottom surface of the pocket in the same direction as the package lower side surface of the electronic component.

According to the article of the present invention which employs such technical means, the lower edge of the package of the electronic component is received by the ribs without gaps from both sides without making it difficult to take the electronic component in and out, and the electronic component is surely delivered. It is possible to prevent the lateral movement of the component, thereby reliably preventing the deformation of the lead wire and preventing the occurrence of defective products.

The article of the present invention will be described in more detail as follows.

In the article of the present invention, the inclination of the rib is
The inclination should be in the same direction as the side surface of the lower portion of the package of the QFP type electronic component or the like housed in the pocket, that is, the ribs located on both sides of the electronic component should spread toward the mouth of the pocket.

However, in order to facilitate the loading and unloading of electronic components, the ribs may be inclined equally to the lower side surface of the package of the electronic component housed in the pocket, or may be inclined more gently than the lower side surface. preferable.

If the inclination angle of the rib is made steeper than the inclination angle of the lower side surface of the package, or if the rib is inclined in the direction opposite to the lower side surface, the ribs can be smoothly inserted in and taken out of the pocket. Like the conventional one in which the upper edge is upright, it is necessary to provide a gap between the rib and the package of the electronic component, and the lead wire may be deformed during transportation.

In particular, when the ribs are inclined in the same direction or in the opposite direction to the lower side surface and at a steeper angle than the lower side surface, it becomes difficult to form the ribs at the same time when forming the pockets. In order to form the above, a complicated process of cutting or punching a part of the bottom surface along the contour of the rib excluding the portion where the rib is continuous with the bottom surface, and then bending the rib must be adopted. However, the process time becomes long and the cost becomes high, which is not preferable.

When the rib is inclined in the direction opposite to the lower side surface, the lead wire may hit the rib and deform the lead wire when the electronic component is housed, depending on the inclination angle.

This rib may be formed, for example, by cutting or punching the bottom surface of the pocket along a required portion of the contour of the rib as in the case of the conventional rib, and then bending it, but the cost is reduced. To achieve this, for example, by the method for manufacturing an embossed tape for electronic parts of the present invention described below,
It is also preferable to use a pocket forming mold of the present invention described later.

[0021] In the embossed tape for electronic parts of the present invention, if a reinforcing rib continuous with the rib and the bottom surface of the pocket is provided as necessary, elastic deformation of the rib is surely prevented, and the lateral side of the electronic part is surely prevented. It is possible to more reliably prevent the movement and the deformation of the lead wire due to the movement.

The reinforcing rib is not particularly limited, but in order to reduce the cost, for example, according to the method for manufacturing an embossed tape for electronic parts of the present invention described later, or by using the pocket forming mold of the present invention described later. It is preferably formed.

Further, in the present invention, when a reinforcing resin is applied to the ribs from the bottom side of the pocket, the ribs are reinforced by the reinforcing resin and are less likely to be deformed. It becomes possible to more reliably prevent the deformation of the line.

The reinforcing resin may be applied only to the rib portion. In this case, when the reinforcing resin is filled in the space surrounded by the rib and the bottom surface of the pocket, the reinforcing resin is reinforced. The effect becomes more remarkable.

Further, the reinforcing resin may be applied to the entire bottom surface of the pocket, including the portion raised to form the rib, to reinforce the entire bottom surface side of the pocket. The embossed tape may be coated over the entire bottom surface side so that the entire embossed tape is reinforced by the reinforcing resin.

Next, in order to achieve the above-mentioned object, the method for manufacturing an embossed tape for electronic parts according to the present invention forms a pocket for accommodating parts on the embossed tape for electronic parts, and simultaneously forms a bottom surface of the pocket. From the above, a technical means is adopted in which a rib inclined in the same direction as the lower side surface of the package of the electronic component with respect to the bottom surface and at a level equal to or lower than the lower side surface is formed. .

According to this method, the rib for preventing the lateral movement of the electronic component is formed at the same time when the pocket is formed. Therefore, the manufacturing process of the embossed tape for the electronic component is simplified, and the production time is short and the cost is low. An embossed tape for electronic parts can be manufactured.

Moreover, the ribs formed are inclined from the bottom surface of the pocket in the same direction as the lower side surface of the package of the electronic component with respect to the bottom surface, and at the same or a lower degree than the lower side surface. Therefore, as described above, it is possible to prevent the lead of the electronic component from being deformed during transportation and the like, and it is possible to prevent the generation of a defective product due to the deformation of the lead.

In the method for producing an embossed tape for electronic parts of the present invention, after forming the pocket, a reinforcing resin is applied from the bottom side of the pocket, if necessary, so that the applied portion, for example, a rib. The bottom surface of the pocket including the rib forming portion, the entire surface of the embossed tape, etc. can be reinforced to enhance the effect of preventing defective products.

Next, the pocket forming die according to the present invention comprises a lower die having a concave portion corresponding to the electronic component storing pocket of the embossed tape for electronic components, and an upper die having a convex portion corresponding to the concave portion. In a pocket forming die including a die, the following technical means is adopted to achieve the above object.

That is, a rib convex portion forming a rib inclined in the same direction as the package lower side surface of the electronic component is provided in the concave portion of the lower die, and the upper die corresponds to the rib convex portion. A means is adopted in which the rib recess is provided.

According to this mold, for example, by sandwiching a tape, which is cut into a predetermined width and has a feed hole, between the upper and lower molds, the upper and lower molds are pressed to each other to form a pocket. Since the ribs can be raised from the bottom surface of the pocket at the same time when the ribs are formed by being pushed down,
The manufacturing process of the embossed tape for electronic parts can be simplified, and the embossed tape for electronic parts can be manufactured at low cost in a short time.

Further, the ribs formed thereby are inclined from the bottom surface of the pocket in the same direction as the lower side surface of the package of the electronic component with respect to the bottom surface, at the same level as the lower side surface, or more gently. As described above, the rib of the electronic component can prevent the lead of the electronic component from being deformed during transportation as described above, and can also prevent defective products due to the deformation of the lead.

[0034]

As described above, in the article of the present invention, the rib is inclined in the same direction as the package lower side surface of the electronic component with respect to the bottom surface of the pocket. There is an effect that the lower edge of the package of the electronic component is received by the ribs without gaps from both sides and the lateral movement of the electronic component can be surely prevented without making the loading and unloading difficult.

Next, according to the method of the present invention, a pocket for storing a component is formed on the embossed tape for an electronic component by being pushed down, and at the same time, the bottom surface of the pocket is oriented in the same direction as the lower side surface of the package of the electronic component. In addition, according to the method of the present invention, the rib is raised at the same time as the pocket is pushed down. In addition to the effect of simplifying the structure, it is possible to form the rib inclined with respect to the bottom surface of the pocket in the same direction as the lower surface of the package of the electronic component.

Next, in the mold of the present invention, a rib convex portion that forms a rib inclined in the same direction as the package lower side surface of the electronic component is provided on the upper surface of the lower mold. Since the rib concave portion corresponding to the rib convex portion is provided as a recess, the metal mold of the present invention has an effect that the rib can be formed at the same time when the pocket is formed. On the other hand, it is possible to form the rib that is inclined in the same direction as the lower side surface of the package of the electronic component.

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION An embossing tape for an electronic component according to an embodiment of the present invention, a method for manufacturing an embossing tape for an electronic component according to an embodiment of the method of the present invention, and a mold for the present invention. The pocket forming die and the die will be specifically described with reference to the drawings. However, the present invention, that is, the present invention article, the present invention method, and the present invention die are limited by this embodiment. Not something.

Now, FIG. 1 is an enlarged sectional view showing an essential part of an embossed tape for electronic parts according to an embodiment of the present invention, and FIG. 2 is a plan view thereof.

As shown in FIG. 2, this embossed tape 1
Is cut into a predetermined width, and a large number of feed holes 2 are formed at one side edge portion thereof at regular intervals in the longitudinal direction, and at a central portion in the width direction at predetermined intervals in the longitudinal direction. It has a large number of pockets 3 formed.

As shown in FIG. 1, each pocket 3 is formed to be larger than the QFP type electronic component 4 housed therein, and the electronic component 4 is formed at the center of the bottom surface 5 of the pocket 3.
A pedestal 6 is formed to receive the bottom surface of the. Also, pocket 3
A peripheral edge portion 7 of the bottom surface 5 is formed to be lower than the pedestal 6 so that the lead wire 8 of the electronic component 4 placed on the stepped portion 6 is lifted from the peripheral edge portion 7.

Ribs 9 and reinforcing ribs 10 continuous with both end edges of each rib 9 and the peripheral edge portion 7 are erected from the peripheral edge portion 7 on each side of the pedestal 6, and each rib 9 is a package of the electronic component 4. It is formed in the same direction as the lower side surface 12 of 11 and so as to be inclined more gently than the lower side surface 12 (for example, inclined by 45 °).

The portion outside the upper edge of each rib 9 is punched out at a steep angle so as not to come into contact with the lead wire 8 of the electronic component 4. Therefore, the upper edge of the rib 9 and the peripheral edge portion 7 are
When the rib 9 is raised, it is sheared.

That is, the pocket 3, the rib 9 and the reinforcing rib 10 of the embossed tape 1 for electronic parts according to this embodiment are
For example, it is formed by using a pocket forming mold including upper and lower molds 21 and 22 shown in the sectional view of FIG.

The lower die 22 has an upper surface 23 corresponding to the bottom surface 5 of the electronic component storage pocket 3 of the embossed tape 1 for electronic components, while the upper die 21 has an upper surface 23 corresponding to the lower die 22. It has a lower surface 24 corresponding to the upper surface 23.

On the upper surface 23 of the lower mold 22, the electronic component 4
The rib convex portion 25 forming the rib 9 that is inclined in the same direction as the lower side surface 12 of the package 11 is projectingly provided, and the rib concave portion 26 corresponding to the rib convex portion 25 is formed on the lower surface 24 of the upper mold 21. Is recessed.

The rib convex portion 25 has an inclined surface 27 corresponding to the inclination of the rib 9 and a shearing surface 28 which is substantially perpendicularly lowered from the upper end of the inclined surface 27, and the rib concave portion 26 is parallel to the inclined surface 27. It is provided with a facing slope 29 and a shearing surface 30 that descends substantially vertically from the upper end of the facing slope 29, and is sandwiched between the upper end 31 of the rib projection 25 and the lower end 32 of the shearing surface 30 of the rib recess 26. The bottom surface 5 of the pocket 3 is configured to be sheared.

An upper mold cushion 33 is provided around the upper mold 21, and a lower mold frame 34 is provided around the lower mold 22, so that the perforated embossed tape 1 has a lower mold frame 34.
Can be placed on. The upper surface 23 of the lower mold 22 is positioned lower than the upper surface of the lower mold frame 34, and
By pushing down the lower surface 24 of the lower mold 24 than the upper surface of the lower mold frame 34, the pocket 3 is hit down. At the same time, a part of the bottom surface 5 of the pocket 3 is pushed up by the rib convex portion 25 to form the rib 9.

According to the embossed tape for electronic parts of this embodiment, the lower edge of the package 11 of the electronic part 4 is provided with the ribs 9 on both sides even if the position of the rib 9 is slightly displaced in the lateral direction.
Since it is reliably received, the gap between the electronic component 4 and the rib 9 is not opened, and the electronic component 4 does not move laterally.

Therefore, the package 11 of the electronic component 4 collides with the rib 9 and the rib 9 is elastically deformed, and the electronic component 4 moves further greatly, and the lead wire 8 forms the rib 9 on the side opposite to the moving direction.
There is also no risk of deformation due to collision with, and it is possible to reliably prevent generation of defective products due to deformation of the lead wires 8 during transportation.

As shown in FIG. 2, a pin hole 13 into which a knock pin for pushing the electronic component 4 upward is inserted is formed in the center of the pocket 3 in plan view.

FIG. 4 is an enlarged sectional view showing an essential part of an embossed tape for electronic parts according to another embodiment of the article of the present invention. In the embodiment shown in FIG. 4, ribs 9 and reinforcing ribs are used. In the space surrounded by 10 and the peripheral portion 7 of the bottom surface 5, the bottom surface 5
The reinforcing resin 14 is filled from the side.

The other construction of this embodiment is the same as that of the previous example. According to this embodiment, the rib 9 and the reinforcing rib 10 are reinforced by the reinforcing resin 14, and the elastic deformation of the rib 9 is prevented more reliably. As a result, the deformation of the lead wire 8 can be prevented more reliably, and as a result, the occurrence of defective products due to the deformation of the lead wire 8 during transportation can be prevented more reliably.

FIG. 5 is an enlarged sectional view showing an essential part of an embossing tape for electronic parts according to another embodiment of the article of the present invention. In the embodiment shown in FIG. 5, the embossing tape 1 is used.
The reinforcing resin 14 is applied from the bottom surface 5 side over the entire surface of the.

The other construction of this embodiment is the same as that of the previous example shown in FIG. 4. According to this embodiment, the embossed tape 1 is entirely reinforced by the reinforcing resin 14 to have the same strength as that of the injection molding. As a result of the elastic deformation of the rib 9 being more reliably prevented, it is possible to more reliably prevent the generation of defective products due to the deformation of the lead wire 8 during transportation.

FIG. 7 is an enlarged cross-sectional view showing an essential part of an embossed tape for electronic parts according to still another embodiment of the article of the present invention shown in FIG. 6, and in the embodiment shown in FIG. It is formed so as to be inclined parallel to the inclination of the lower side surface 12 of the package 11.

The other construction of this embodiment is the same as that of the embodiment of the present invention shown in FIGS. 1 to 3, and its operation and effect are the same as those of the embodiment of the present invention. is there.

If the inclination angle of the rib 9 is made steeper than the inclination angle of the lower side surface 12, the same problem as in the conventional one in which the upper edge of the rib 9 is upright may occur, and the rib 9 may be removed. It becomes difficult to form the pocket 3 in the same manner as the formation of the pocket 3, and in order to form the rib 9, a part of the bottom surface 5 is cut along the contour of the rib 9 except the portion where the rib 9 is continuous with the bottom surface. Alternatively, a complicated process of punching and then bending the rib 9 must be adopted, which is not preferable because the process time becomes long and the cost becomes high.

[0058]

As described above, in the article of the present invention, the rib is inclined with respect to the bottom surface of the pocket in the same direction as the package lower side surface of the electronic component. Without making it difficult to put in and take out the electronic parts, the lower edge of the package of the electronic parts is received from both sides by the ribs without any gaps, and it is possible to reliably prevent the lateral movement of the electronic parts. As a result, it is possible to surely prevent the lead wire from being deformed by the lateral movement of the component in the pocket. As a result, it is possible to prevent defective products from being generated due to the deformation of the lead wire during transportation.

Next, in the method of the present invention, a pocket for storing a component is formed on the embossed tape for an electronic component by punching down, and at the same time, the bottom surface of the pocket is flush with the lower side surface of the package of the electronic component. Since the ribs which are inclined in the same direction as the lower side surface, or which are inclined more gently than the lower side surfaces, are raised, according to the method of the present invention, the ribs are raised at the same time when the pockets are pushed down. As a result, it is possible to obtain an effect that a significant cost reduction can be achieved.

Further, according to the method of the present invention, it is possible to form a rib inclined to the bottom surface of the pocket in the same direction as the side surface of the lower part of the package of the electronic component. As a result, it is possible to more surely prevent the electronic component from laterally moving in the pocket and deforming the lead wire, and as a result, it is possible to prevent the generation of defective products due to the deformation of the lead wire during transportation.

Next, in the mold of the present invention, a rib convex portion forming a rib inclined in the same direction as the package lower side surface of the electronic component is provided on the upper surface of the lower mold, while the upper mold is formed. Since the rib concave portion corresponding to the rib convex portion is provided as a recess, according to the mold of the present invention, there is an effect that the rib can be formed at the same time when the pocket is formed. It is possible to obtain an effect that it becomes simple and a large cost reduction can be achieved.

Further, in the mold of the present invention, since it is possible to form a rib inclined to the bottom surface of the pocket in the same direction as the side surface of the lower part of the package of the electronic component, during transportation, etc. As a result, it is possible to reliably prevent the electronic component from laterally moving in the pocket and deforming the lead wire, and as a result, it is possible to eliminate the occurrence of defective products due to the deformation of the lead wire.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of an essential part showing a first embodiment of the present invention.

FIG. 2 is an enlarged plan view of an essential part showing a first embodiment of the present invention.

FIG. 3 is an enlarged sectional view of an essential part showing a mold suitably used for manufacturing the embossed tape for electronic parts of the present invention.

FIG. 4 is an enlarged sectional view of an essential part showing a second embodiment of the present invention.

FIG. 5 is an enlarged sectional view of an essential part showing a third embodiment of the present invention.

FIG. 6 is an enlarged sectional view of an essential part showing a fourth embodiment of the present invention.

[Explanation of symbols]

1 embossed tape 3 pockets 4 electronic components 5 Bottom 9 ribs 10 Reinforcing rib 11 packages 12 Lower side 21 Upper mold 22 Lower mold 23 Top 24 Lower surface 25 Convex part for rib 26 Rib recess 27 slope 28 shear plane 29 Opposite slope 30 shear plane 31 top 32 bottom

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3E067 AA11 AB41 AC04 BA34A                       EC09 EE39 FA01 GD03                 3E096 AA06 BA08 CA13 DA03 DA08                       DA23 DB01 DC01 FA09 FA10                       GA05                 4F209 AG05 PA02 PB02 PC05 PQ11

Claims (13)

[Claims] 1. An embossed tape for electronic components, comprising: an electronic component storage pocket; and a rib raised from the bottom surface of the pocket so as to sandwich the electronic component stored in the pocket, wherein the rib is the pocket. An embossed tape for electronic parts, which is inclined in the same direction as the side surface of the lower part of the package of the electronic part with respect to the bottom surface of the. 2. The embossed tape for an electronic component according to claim 1, wherein the rib is inclined parallel to a lower side surface of the package of the electronic component housed in the pocket. 3. The embossed tape for electronic parts according to claim 1, wherein the rib is inclined more gently than the side surface of the lower part of the package of the electronic part housed in the pocket. 4. The rib according to claim 1, wherein the rib is formed by punching a part of the bottom surface of the pocket.
The embossed tape for electronic parts according to the item. 5. The embossed tape for electronic parts according to claim 1, further comprising a reinforcing rib continuous with the rib and the bottom surface of the pocket. 6. The embossed tape for electronic parts according to claim 5, wherein the reinforcing rib is formed by punching a part of the bottom surface of the pocket together with the rib. 7. The embossed tape for electronic parts according to claim 1, wherein a reinforcing resin is applied to the rib from the bottom side of the pocket. 8. The embossed tape for electronic parts according to claim 7, wherein the reinforcing resin is filled in a space surrounded by the rib and the bottom surface of the pocket. 9. The embossed tape for electronic parts according to claim 7, wherein the reinforcing resin is applied to the entire bottom surface of the pocket. 10. The embossed tape for electronic parts according to claim 7, wherein the reinforcing resin is applied from the bottom side of the pocket to the entire surface of the embossed tape. 11. An embossed tape for electronic parts is formed by punching down a pocket for accommodating parts, and at the same time, from the bottom surface of the pocket to the bottom surface in the same direction as the side surface of the lower part of the package of the electronic parts and the lower part. A method for producing an embossed tape for electronic parts, which comprises forming ribs that are equal to or slightly inclined to the side surfaces. 12. A pocket forming die comprising a lower die having an upper surface corresponding to a pocket for storing an electronic component of an embossed tape for an electronic component and an upper die having a lower surface corresponding to the upper surface, wherein the lower die On the upper surface of the mold, a rib protrusion that forms a rib inclined in the same direction as the package lower side surface of the electronic component is provided,
A pocket forming mold, wherein a rib recess corresponding to the rib protrusion is provided in the upper mold. 13. The rib protrusion has an inclined surface corresponding to the inclination of the rib, and a shearing surface that descends substantially vertically from the upper end of the inclined surface, and the rib recess has an opposed inclined surface parallel to the inclined surface and an opposed inclined surface parallel to the inclined surface. 13. A bottom surface of the pocket sandwiched between an upper end of the rib protrusion and a lower end of the rib recess shear surface is sheared.
The mold for forming a pocket described in.