CN215787419U - Stitch fixing device, welding joint and ultrasonic welding machine - Google Patents

Abstract

The practical utility model discloses a novel pin fixing device, which comprises a cylindrical signal pin mounting part, wherein a downward mounting hole is formed in the signal pin mounting part from the top surface, a signal pin is inserted and fixed in the mounting hole, the bottom surface of the signal pin mounting part is a flat bottom plate with a section larger than that of the signal pin mounting part, the size of the mounting hole is matched with that of an inserting part of the signal pin, and the size of the section of the signal pin mounting part is unchanged from the upper surface of the signal pin mounting part to the bottom surface of the signal pin mounting part; the utility model also discloses a welding joint and an ultrasonic welding machine, and the ultrasonic welding stitch fixing device can be welded through ultrasonic waves by arranging the accommodating cavity. By using the technical scheme disclosed by the utility model, the pin fixing device can be fixed on the substrate in an ultrasonic welding mode, so that the pin fixing device can be quickly and accurately installed at a preset position, and various problems of solder splash, welding cavities, device turnover and the like are avoided.

Description

Stitch fixing device, welding joint and ultrasonic welding machine

Technical Field

The utility model relates to the technical field of ultrasonic welding, in particular to a pin fixing device for fixing a contact pin, a welding joint for performing ultrasonic welding on the pin fixing device and an ultrasonic welding machine.

Background

In the field of semiconductor device packaging technology of the inventor, a common power device realizes the electrical connection between a chip and the outside through a pin. However, for some special fields, in addition to using the general performance of the power device by using a general power device, the customer needs to arrange a signal connection device on the power device according to the design of some functions.

For such customer needs, the prior art provides a common practice of mounting signal pins on a substrate of a power device packaged in an existing design. In order to fix the signal pin on the power device, a pin fixing device is fixed at a predetermined position of a substrate of the power device, and a mounting hole for connecting the signal pin is formed in the pin fixing device. And the customer can install the signal pin on the required pin fixing device according to the requirement of the functional design of the customer.

The prior art method for fixing the pin fixing device on the substrate is as follows: firstly, designing a preset position on a substrate, where a pin fixing device is required to be installed, according to the requirement of functional design; then printing solder paste on a preset position; placing the pin fixing device on solder paste at a preset position, and performing vacuum reflow soldering on the power device with the pin fixing device; and cleaning the whole power device after welding.

The prior art provides a pin fixing device for the method, and the pin fixing device is designed to be I-shaped. The two ends of the pin fixing device are provided with a flat top plate and a flat bottom plate, the cross-sectional dimension of the flat top plate is larger than that of the middle main body. The main body part for connecting the flat top plate and the flat bottom plate is provided with mounting holes penetrating through the flat top plate, the main body part and the flat bottom plate, and the mounting holes are used for mounting and fixing the signal pins. Wherein the flat top plate and the flat bottom plate are of identical shape and size, i.e. they can be converted into a flat bottom plate when the flat top plate is placed underneath, and the flat bottom plate is converted into a flat top plate. The flat top plate or the flat bottom plate is used for increasing the area in contact with solder paste, so that the contact area between the pin fixing device and the substrate is increased, and the mounting stability of the pin fixing device is improved. The uniformity design of flat roof and flat bottom plate simultaneously can be so that stitch fixing device need not distinguish when fixing to the base plate whether top surface or bottom surface, because no matter be the bottom surface or the top surface can all be regarded as the stationary plane of being connected with the base plate to improve the efficiency of laying stitch fixing device.

However, the above-mentioned prior art provides the following problems in the process of fixing the pin fixing device to the substrate:

1. in vacuum reflow soldering, bubbles inside the solder can be broken under pressure, so that the solder is splashed, and the power device and the pin fixing device are affected (as shown in fig. 1);

2. because the thickness of the soldering tin cannot be completely controlled, the weight of the pin fixing device is not completely consistent, so that the soldering tin between the pin fixing device and the substrate may be insufficient to form welding layer cavities (as shown in fig. 2); meanwhile, the balance degree (i.e. the mounting hole of the pin fixing device is always kept perpendicular to the substrate) and the height (i.e. the distance between the top surface of the pin fixing device and the substrate) of the pin fixing device are difficult to control; this also leads to problems with unsmooth insertion of the signal pin into the pin fixture at a later time.

3. In the process of placing the pin fixing device to vacuum reflow soldering, the pin fixing device inevitably has the problems of overturning (namely, the mounting hole of the pin fixing device is parallel to the substrate, as shown in fig. 3), deviation (namely, the position fixed by the pin fixing device is deviated from the preset mounting position, as shown in fig. 4) and the like. The pin fixing device which can not insert the signal pin into the corresponding position or the signal pin inserted into the pin fixing device is deviated in position, and the corresponding signal connection can not be realized.

SUMMERY OF THE UTILITY MODEL

Aiming at the problems existing in the prior art of fixing the pin fixing device by printing solder paste and vacuum reflow soldering, the technical scheme of the utility model changes the process and adopts the ultrasonic welding which is used in the prior semiconductor packaging to fix the pin fixing device on the substrate. However, the welding joint of the existing ultrasonic welding machine is not suitable for welding the pin fixing device on the substrate, so the utility model provides a welding joint and a pin fixing device at the same time, thereby realizing the purpose of fixing the pin fixing device on the substrate by ultrasonic welding.

The utility model provides a pin fixing device which comprises a cylindrical signal pin mounting part, wherein a downward mounting hole is formed in the signal pin mounting part from the top surface, a signal pin is inserted and fixed in the mounting hole, the bottom surface of the signal pin mounting part is a flat bottom plate with the section larger than that of the signal pin mounting part, the size of the mounting hole is matched with that of an inserting part of the signal pin, and the size of the section of the signal pin mounting part is unchanged from the upper surface of the signal pin mounting part to the bottom surface of the signal pin mounting part.

Compared with the pin fixing device provided by the prior art, the pin fixing device provided by the utility model has the advantages that the flat top plate on the top surface of the signal pin installation part is eliminated, and only the flat bottom plate on the bottom surface of the signal pin installation part is reserved. Through the improvement, the pin fixing device can be conveniently inserted into the accommodating cavity of the welding joint from the top surface by matching with the welding joint provided by the utility model, so that the pin fixing device can be placed on the welding joint, then the pin fixing device is moved to the preset position of the substrate by the welding joint, and the flat bottom plate of the pin fixing device is fixed on the substrate by ultrasonic welding while the pin fixing device is placed at the preset position of the substrate by the welding joint. In this installation, can not produce soldering tin and splash, can accurate control completely to the position that stitch fixing device laid simultaneously, stitch fixing device's fixed direction is also controllable, avoids appearing the welding layer hole, stitch fixing device upset or displacement scheduling problem. The quality of the pin fixing device fixed on the substrate is improved. The signal pins (namely the contact pins) can be inserted into the mounting holes quickly and accurately in the following process.

Preferably, the mounting hole includes a first introduction hole and a first straight hole, the upper portion of the first introduction hole penetrates through the upper surface of the signal needle mounting portion, the lower portion of the first introduction hole is connected with the upper portion of the first straight hole, the cross-sectional size of the first introduction hole decreases from top to bottom, the first straight hole extends towards the bottom surface of the signal needle mounting portion along the direction of the signal needle mounting portion, and the size of the first straight hole is matched with the size of the insertion portion of the signal needle. The first leading-in hole has a diameter from top to bottom which is reduced, so that the signal needle can be guided to be rapidly inserted into the mounting hole.

The welding joint provided by the embodiment of the utility model is used for welding the pin fixing device to a preset position. The welding head comprises a bottom surface used for being in contact with a welding workpiece, the welding head is provided with an accommodating cavity formed by inwards extending from the bottom surface, and the size of the accommodating cavity is matched with a signal needle mounting part of the stitch fixing device; the ultrasonic welding machine also comprises an installation part fixedly connected with the welding head, and the installation part is used for connecting a transducer of the ultrasonic welding machine.

According to the welding joint provided by the embodiment of the utility model, the accommodating cavity is formed by extending the bottom surface of the welding joint inwards, and the size of the accommodating cavity is matched with that of the signal needle mounting part of the pin fixing device, so that the pin fixing device can be fixed when the pin fixing device is inserted into the accommodating cavity, and the welding joint can be conveniently moved to a preset position on a substrate under the control of an ultrasonic welding machine. When the welding joint places the pin fixing device at a preset position on the substrate, the ultrasonic welding machine controls the welding joint to generate high-frequency mechanical vibration, the welding joint enables the high-frequency mechanical vibration to act on the pin fixing device, so that friction is generated between the flat bottom plate of the pin fixing device and the contact surface of the substrate, a large amount of heat is generated, the heat is fused with the contact surface of the pin fixing device and the substrate, and the pin fixing device and the substrate are firmly welded together. In the ultrasonic welding process, soldering tin is not needed, and the position and the direction of the pin fixing device can be accurately controlled. Therefore, the problems caused by the adoption of soldering tin and vacuum reflow soldering can be solved. The quality of the pin fixing device fixed on the substrate is improved. The signal pin can be inserted into the mounting hole quickly and accurately.

Preferably, the depth of the accommodating cavity is not less than the distance from the top surface of the signal pin mounting part to the upper surface of the flat bottom plate.

Preferably, the receiving cavity extends from a bottom surface of the welding head to the mounting portion.

Preferably, the bottom surface of the welding head is provided with grid-shaped protrusions.

Preferably, the welding head is fixedly connected with the mounting part through a connecting rod, and the mounting part, the connecting rod and the welding head are integrally formed.

Preferably, the cross section of the mounting part is circular, the radius of the mounting part is R, the cross section of the connecting rod is also circular, the radius of the connecting rod is R, the welding head is a square pipe or a circular pipe, the side length or the radius of the welding head is a, and a < R.

Based on the same object, the embodiment of the utility model provides an ultrasonic welding machine, and the ultrasonic welding machine comprises the welding joint provided by the embodiment.

The description of the working principle of the ultrasonic welding machine and the technical effect achieved by using the ultrasonic welding machine provided by the utility model can be specifically referred to the description of the welding joint, and the action principle and the achievable effect are consistent.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIGS. 1 to 4 are schematic diagrams illustrating problems caused by a solder reflow process according to the prior art;

FIG. 5 is a schematic perspective view of a pin fixing device according to an embodiment of the present invention;

FIG. 6 is a schematic perspective view of a weld joint according to an embodiment of the present invention

FIG. 7 is an enlarged effect diagram of area E in FIG. 6;

FIG. 8 is a front view of a weld joint provided by an embodiment of the present invention

FIG. 9 is a schematic view of FIG. 8 taken along section line A-A;

FIG. 10 is a schematic diagram illustrating the enlargement of the area B in FIG. 9;

FIG. 11 is a diagram illustrating the effect of the present invention on the substrate to which the pin fixture is attached.

In the figure: 31. an installation part; 32. welding a head; 33. a connecting rod; 34. a bottom surface; 35. an accommodating cavity; 41. a flat base plate; 42. Mounting holes; 43. a signal pin mounting part.

Detailed Description

In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be clearly and completely described below through embodiments with reference to the accompanying drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the description of the present invention, the meaning of a plurality is one or more, the meaning of a plurality is two or more, and the above, below, exceeding, etc. are understood as excluding the present numbers, and the above, below, within, etc. are understood as including the present numbers. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present invention, unless otherwise explicitly defined, terms such as set, etc. should be broadly construed, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the detailed contents of the technical solutions.

In the description of the present invention, reference to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples," etc., means that a particular feature or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The prior art provides an exemplary illustration of an ultrasonic welding machine that can be used with the solution of the present invention, which includes:

a frame providing a mounting platform for various components;

the ultrasonic die is used for fixing and positioning a workpiece to be welded;

the ultrasonic generator is used for converting the fifty-hertz power frequency alternating current into a high-frequency alternating current not lower than twenty kilohertz;

the energy converter is used for converting high-frequency alternating current electric energy into high-frequency mechanical vibration;

the amplitude transformer is connected with the transducer, provides a position for fixing the welding external member to the pressure device, and simultaneously amplifies the mechanical vibration generated by the transducer and transmits the vibration to the welding joint;

the welding joint fixedly connected with the amplitude transformer is mainly used for acting on the surfaces of the two workpieces to be welded so as to act mechanical vibration on the surfaces of the two workpieces to be welded, so that the surfaces of the two workpieces to be welded generate friction, and the two workpieces to be welded are pressed tightly;

the pressure device is connected with the transducer and used for providing pressure to the welding joint through the transducer;

the control system, the brain of the entire torque type ultrasonic welding machine, controls the operation of the ultrasonic welding machine, including setting the frequency, setting the duration of the welding action, the applied pressure, and the angle of rotation, etc., which are not described in detail herein.

To the problem that prior art fixed the technology production on the base plate with stitch fixing device, utility model people have abandoned this set of technology on the basis of the abundant research, but have borrowed ultrasonic welding machine to through the welded joint who improves ultrasonic welding machine and improve stitch fixing device's structure, directly fix stitch fixing device on the base plate through ultrasonic welding union piece, thereby solved the problem that prior art brought well. A good effect is achieved.

The first embodiment:

as shown in fig. 5 and 10, the embodiment of the present invention improves the pin fixing device to adapt to the ultrasonic welding process for fixing the pin fixing device on the substrate. The utility model provides a pin fixing device which comprises a cylindrical signal pin mounting part 43, wherein a downward mounting hole 42 is formed in the signal pin mounting part 43 from the top surface, a signal pin is inserted and fixed in the mounting hole 42, the bottom surface of the signal pin mounting part 43 is a flat bottom plate 41 with the section larger than that of the signal pin mounting part, the size of the mounting hole 42 is matched with that of an inserting part of the signal pin, and the size of the section of the signal pin mounting part 43 is unchanged from the upper surface of the signal pin mounting part 43 to the bottom surface of the signal pin mounting part 43.

The size of the mounting hole is matched with the size of the inserting part of the signal needle, and the size, the shape or the set threads of the mounting hole are matched to enable the signal needle to be fixed on the pin fixing device.

Compared with the pin fixing device provided by the prior art, the pin fixing device provided by the utility model has the advantages that the flat bottom plate on the top surface of the signal pin installation part is eliminated, and only the flat bottom plate on the bottom surface of the signal pin installation part is reserved. Through the improvement, the pin fixing device can be conveniently inserted into the accommodating cavity of the welding joint from the top surface by matching with the welding joint provided by the utility model, so that the pin fixing device can be placed on the welding joint, then the pin fixing device is moved to the preset position of the substrate by the welding joint, and the flat bottom plate of the pin fixing device is fixed on the substrate by ultrasonic welding while the pin fixing device is placed at the preset position of the substrate by the welding joint. In this installation, can not produce soldering tin and splash, can accurate control totally to the position that stitch fixing device laid simultaneously, stitch fixing device's fixed direction is also controllable, avoids appearing the welding layer cavity, stitch fixing device upset or displacement scheduling problem. The quality of the pin fixing device fixed on the substrate is improved. The signal pins (namely the contact pins) can be inserted into the mounting holes quickly and accurately in the following process.

In a preferred embodiment, the mounting hole 42 includes a first introduction hole having an upper portion penetrating through the upper surface of the signal needle mounting portion and a lower portion connected to the upper portion of the first introduction hole, the first introduction hole having a cross-sectional size decreasing from top to bottom, and a first straight hole extending toward the bottom surface of the signal needle mounting portion in the direction of the signal needle mounting portion, wherein the size of the first straight hole is adapted to the size of the insertion portion of the signal needle. The first lead-in hole is arranged at the inlet of the mounting hole, and the size of the first lead-in hole is larger than that of the first straight hole, namely the size of the first lead-in hole is larger than that of the inserting part of the signal pin, so that the signal pin can be mounted in the mounting hole conveniently.

Second embodiment:

the preferred embodiment of the present invention provides a weld joint for welding a stitch fixture as shown in fig. 6 to 10. The welding joint provided by the embodiment of the utility model is used for welding the pin fixing device of the first embodiment to a preset position. The welding head 32 is provided with a bottom surface 34 used for contacting with a welding workpiece, the welding head 32 is provided with a containing cavity 35 formed by extending inwards from the bottom surface 34, and the size of the containing cavity 35 is matched with the signal pin mounting part 43 of the pin fixing device; the ultrasonic welding device further comprises a mounting part 31 fixedly connected with the welding head 32, and the mounting part 31 is used for connecting a transducer of an ultrasonic welding machine.

The size of the accommodating cavity 35 is adapted to the signal needle mounting portion of the pin fixing device, which means that the shape and size of the accommodating cavity 35 are substantially close to the shape and size of the outer contour of the signal needle mounting portion 43, so that when the signal needle mounting portion is inserted into the accommodating cavity 35, the inner wall of the accommodating cavity is attached to the outer wall of the signal needle mounting portion, and accordingly, the pin fixing device cannot slide down obviously in the process that the welding joint moves to a preset position by means of the friction force generated between the inner wall and the outer wall, namely, the sliding distance of the pin fixing device does not exceed a preset value, such as the sliding distance does not exceed one fourth of the length of the signal needle mounting portion.

The shape of the accommodating cavity 35 is adapted to the insertion part of the signal pin. General stitch fixing device, its signal needle installation department adopts cylindrically, consequently, the shape in holding chamber generally sets up to the round hole, and the internal diameter in holding chamber is slightly bigger than the external diameter of stitch fixing device signal needle installation department to the holding chamber 35 can be inserted to the signal needle installation department under the circumstances of not taking effort, and stitch fixing device can not produce obvious gliding under the action of gravity simultaneously and be standard design. The shape and size of the pin fixing device can be set as standard, and the shape and size of the accommodating cavity can be set as standard correspondingly.

According to the welding joint provided by the embodiment of the utility model, the accommodating cavity is formed by inwards extending the bottom surface of the welding joint, the size of the accommodating cavity is matched with that of the signal needle mounting part of the pin fixing device, and the pin fixing device can be fixed when the signal needle mounting part is inserted into the accommodating cavity. Therefore, the welding joint can be conveniently moved to a preset position on the substrate under the control of the ultrasonic welding machine. When the welding joint places the pin fixing device at a preset position on the substrate, the ultrasonic welding machine controls the welding joint to generate high-frequency mechanical vibration, the welding joint enables the high-frequency mechanical vibration to act on the pin fixing device, so that friction is generated between the flat bottom plate of the pin fixing device and the contact surface of the substrate, a large amount of heat is generated, the heat is fused with the contact surface of the pin fixing device and the substrate, and the pin fixing device and the substrate are firmly welded together. In the ultrasonic welding process, soldering tin is not needed, and the position and the direction of the pin fixing device can be accurately controlled. Therefore, the problems caused by the adoption of soldering tin and vacuum reflow soldering can be solved. The quality of the pin fixing device fixed on the substrate is improved. The signal pins (namely the contact pins) can be inserted into the mounting holes quickly and accurately in the following process.

In a preferred embodiment, the depth of the receiving cavity is not less than the distance from the top surface of the signal pin mounting portion to the upper surface of the flat bottom plate, so that the signal pin mounting portion 43 (see fig. 5 and 10) of the pin fixing device is integrally inserted into the receiving cavity 35, and the bottom surface 34 of the soldering head can contact with the upper surface of the flat bottom plate 41 of the pin fixing device, which is beneficial to the bottom surface 34 of the soldering joint to apply high-frequency mechanical vibration to the contact surface of the pin fixing device and the substrate, and has better soldering effect. Specifically, the accommodating chamber 35 may extend all the way through the solder joint, i.e., be connected to the mounting portion 31, from the bottom surface of the solder head 32, thereby reducing the difficulty of disposing the accommodating chamber. Meanwhile, a through hole may be provided on the mounting portion 31.

Preferably, the base surface 34 of the welding head is provided with a grid of projections, which may be shaped as an equilateral triangular pyramid, i.e. such that one base surface of the triangular pyramid is fixed to the rectangular base surface and one apex projects beyond the base surface. The triangular pyramids may be arranged to form an array along the length and width, respectively. Through setting up latticed arch, be more favorable to on the contact plane with two work pieces of waiting to weld the high-frequency mechanical vibration transmission of welded joint, improve welding efficiency.

In a preferred embodiment, the accommodating cavity 35 includes a second introduction hole and a second straight hole, the lower portion of the second introduction hole is connected with the bottom surface of the welding head, the upper portion of the second introduction hole is connected with the lower portion of the second straight hole, the size of the second straight hole is matched with that of the signal pin mounting portion, and the cross-sectional size of the second introduction hole increases from the upper portion to the lower portion of the second introduction hole. Thereby be provided with the comparatively great leading-in portion of size at the entrance in holding chamber, this size can be bigger than the size of the part that needs insert the holding chamber, is favorable to improving the efficiency that the signal needle installation department of stitch fixing device inserted the holding intracavity.

The welded joint is further provided with a connecting rod 33, the connecting rod 33 fixedly connecting the welding head 32 and the mounting portion 31. The welding head 32, the connecting rod 33 and the mounting portion 31 can be integrally formed to improve the connection rigidity therebetween, thereby facilitating the transmission of high-frequency mechanical vibration and pressure to the respective portions. The mounting portion 31 is circular in overall cross section, and given a radius R, the connecting rod 33 is also circular in cross section, and given a radius R, the cross section of the bonding head may be square or circular, and its side length or radius is a, where a < R. Namely, the sectional dimension from the mounting part to the welding head is smaller and smaller, and the sectional area is smaller and smaller. The application provides a be used for ultrasonic bonding's joint, the last region that supplies the welded joint work of power component is limited, simultaneously, other electronic components in addition on the base plate, stitch fixing device's cross-section is all very little. This allows the dimensioning of the welding head to be comparatively small. However, if the entire welded joint is set to the same size as the welded joint, it inevitably results in a too small contact area between the mounting portion and the ultrasonic welding machine for fixing the mounting portion, which is disadvantageous to the stability of the mounting, and the conduction of high-frequency mechanical vibration and pressure to the welded joint. Therefore, the three-stage welding head is provided with three stages, and the sizes of the three stages are reduced step by step, so that the requirements of the welding head on the size and the installation part on the installation are met, and possible obstacles can be avoided in the middle.

A transition portion extending from the connecting rod to the welding head is provided between the welding head 32 and the connecting rod 33, and the included angle between the side surface of the transition portion and the central axis of the connecting rod is not less than 15 degrees and not more than 45 degrees. In a preferred embodiment, the angle is 30 degrees. Through setting up the transition portion for be connected more firmly between soldered connection and the connecting rod.

The third embodiment:

the embodiment of the utility model provides an ultrasonic welding machine, which comprises: the main parts of the ultrasonic welding machine provided by the prior art, such as a machine frame, an ultrasonic generator, a transducer, an amplitude transformer, a control system and other necessary components. The main improvement point of the ultrasonic welding machine provided by the utility model and the ultrasonic welding machine provided by the prior art is that the welding joint used by the ultrasonic welding machine is the welding joint provided by the second embodiment. The specific structure of the welded joint is referred to the second embodiment and will not be repeated here.

According to the ultrasonic welding machine provided by the embodiment of the utility model, the stitch fixing device can be welded by the ultrasonic welding machine through the improvement of the welding joint. Thereby providing a new mounting process for securing the pin fixture to the base. The pin fixing device fixed by ultrasonic welding provided by the embodiment of the utility model has the advantages that the installation position can be accurately controlled, and the installation state such as balance and height can be accurately controlled. Because when laying stitch fixing device on the base plate, just carry out ultrasonic bonding immediately, be about to stitch fixing device firmly fix on the base plate, just also avoided stitch fixing device to overturn, fixed position skew scheduling problem, avoided the problem that soldering tin splashes more. The whole treatment process is simple and quick, and the fixing effect is good (as shown in figure 11).

The foregoing is considered as illustrative of the preferred embodiments of the utility model and the technical principles employed. It will be understood by those skilled in the art that the present application is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the application. Therefore, although the present application has been described in more detail with reference to the above embodiments, the present application is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present application, and the scope of the present application is determined by the scope of the appended claims.

Claims (10)

1. Stitch fixing device, its characterized in that: including the signal needle installation department that is the cylindricality, downward mounting hole is formed from the top surface to the signal needle installation department, the mounting hole supplies the signal needle to insert fixedly, the bottom surface of signal needle installation department is greater than the flat bottom plate in signal needle installation department cross-section for the cross-section, the size of mounting hole and the grafting portion size adaptation of signal needle follow the upper surface of signal needle installation department toward the bottom surface of signal needle installation department, the cross sectional dimension of signal needle installation department is unchangeable.

2. The pin holder according to claim 1, wherein the mounting hole includes a first introduction hole and a first straight hole, an upper portion of the first introduction hole penetrates through an upper surface of the signal pin mounting portion, a lower portion of the first introduction hole is connected to an upper portion of the first straight hole, a cross-sectional dimension of the first introduction hole decreases from top to bottom, the first straight hole is formed by extending toward a bottom surface of the signal pin mounting portion in a direction of the signal pin mounting portion, and a size of the first straight hole is adapted to a size of the insertion portion of the signal pin.

3. Welded joint, its characterized in that: the pin fixture as claimed in claim 1 or 2, which comprises a welding head, the welding head comprises a bottom surface for contacting with a welding workpiece, the welding head is provided with a containing cavity formed by extending inwards from the bottom surface, and the size of the containing cavity is matched with the signal pin mounting part of the pin fixture; the ultrasonic welding machine also comprises an installation part fixedly connected with the welding head, and the installation part is used for connecting a transducer of the ultrasonic welding machine.

4. The weld joint of claim 3, wherein: the depth of the accommodating cavity is not less than the distance from the top surface of the signal pin mounting part to the upper surface of the flat bottom plate.

5. The weld joint of claim 4, wherein: the accommodating cavity extends from the bottom surface of the welding head to the mounting part.

6. The weld joint of any one of claims 3 to 5, wherein: the bottom surface of the welding head is provided with latticed bulges.

7. The weld joint of claim 6, wherein: the welding head is fixedly connected with the mounting part through a connecting rod, and the mounting part, the connecting rod and the welding head are integrally formed.

8. The weld joint of claim 7, wherein: the cross section of the installation part is circular, the radius of the installation part is R, the cross section of the connecting rod is also circular, the radius of the connecting rod is R, the welding head is a square tube or a circular tube, the side length or the radius of the welding head is a, and a < R < R.

9. The weld joint of any one of claims 3 to 5, wherein: the accommodating cavity comprises a second lead-in hole and a second straight hole, the lower part of the second lead-in hole is connected with the bottom surface of the welding head, the upper part of the second lead-in hole is connected with the lower part of the second straight hole, the size of the second straight hole is matched with the outer diameter of the signal needle mounting part, and the cross section size of the second lead-in hole from the upper part to the lower part of the second lead-in hole is increased.

10. An ultrasonic welding machine comprising a weld joint as claimed in any one of claims 3 to 9.

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