JP4253273B2 - Heater chip for wiring connection - Google Patents

Description

  The present invention relates to a heater chip of a resistance welder used for connecting a lead wire to an electrode of an electrical component, for example.

  The inventor of the present application has already applied for a patent for “heater chip for thermocompression bonding” for use in the above-described wiring connection work as “Japanese Patent Application No. 2002-139666” and “Japanese Patent Application No. 2003-299002”. .

  An outline of the basic structure of the “thermocompression heater chip” of the prior application invention will be described below with reference to FIG. 1 as an accompanying drawing of the present invention.

In other words, a metal plate piece shaped like a “shogi piece” is used as the main body 1 of the heater chip, and its longitudinal dimension is about a few tens of millimeters.
On the front end side of the main body 1, there is provided a small pressure-like heating pressure contact portion 2 that generates heat due to an energizing resistance, and in the vicinity thereof, a temperature detection portion 3a of a thermocouple 3 for temperature detection of the heating pressure contact portion 2 is attached.

  And the energization terminal which provided the cut | interruption a in the cut shape toward the vicinity of the heating-pressure-welding part 2 from the center part of the base end side, and each of the both sides of the cut | interruption a doubles as the attachment base part of a heater chip. Part 1a is used. Reference numeral 10 denotes a mounting hole.

The main body 1 is generally made by forging a tungsten alloy.
In this forging process, an irregular laminated structure is formed in the main body 1 in the thickness direction as shown in FIG.

Japanese Patent Application No. 2002-139666 Japanese Patent Application No. 2003-299002

Heater chips used for connecting lead wires to the electrodes of electrical components are always subject to variations in the heat generation characteristics between the individual heater chips to ensure that they are always connected in good condition. It is required to reduce it.
Each time the heater chip is replaced with a new one, it is necessary to check for the above-mentioned variation and, if necessary, perform troublesome work for correcting the variation.

  In order to save this troublesome correction work as much as possible, not only the material management of the main body 1 but also the dimensional accuracy of each part of the main body 1, the mounting state of the thermocouple temperature detection part by thermal welding, or the power supply It is necessary to strictly manage the flatness of the abutting surface of the energizing terminal portion 1a that abuts on the side chip mounting surface.

  It is also important to take measures to accurately grasp the renewal period of the heater chip whose heat generation characteristics (heat generation temperature distribution) change over time by repeatedly receiving intense heat and cooling.

Further, the heating and pressure welding portion 2 of the main body 1 having the above-described irregular laminated structure is repeatedly ignited and cooled, so that a delamination phenomenon gradually occurs in the vicinity of the heating and pressure welding portion 2. Finally, it is necessary to cope with the fear that the temperature measuring part 3a of the thermocouple 3 may be peeled off.
However, with respect to the problem of peeling off of the temperature measuring section 3a, considerable measures are taken in the above-mentioned prior invention.

  Accordingly, an object of the present invention is to reduce the variation in the heat generation characteristics between the heater chips as much as possible, and at the same time, it is easy to renew the heater chip by detecting the change over time in the heat generation characteristics of the heater chips. It is to provide a heater chip for wiring connection that has been improved so that it can be grasped.

In order to achieve the above object, a heater chip for wiring connection according to the present invention,
A small protrusion-like heating pressure contact portion 2 that generates heat due to an energizing resistance is provided on the distal end side of the main body 1 made of a metal plate piece, and a cut line a is formed from the central portion on the base end side toward the vicinity of the heating pressure contact portion 2. Provided with a notch shape, each of the both sides of the cut a is a current-carrying terminal portion 1a, and has a configuration in which a temperature sensor for temperature detection is attached in the vicinity of the heating pressure contact portion 2.
A temperature measuring unit 6a of the auxiliary temperature sensor 6 is provided at a position spaced apart from the temperature measuring unit 3a of the temperature sensor 3 for temperature detection of the heating pressure welding unit 2,
As the oxidation phenomenon of the main body 1 progresses in the vicinity S of the heated pressure welding portion 2 that is ignited, the degree to which the temperature distribution of the vicinity S changes with time is determined between the two temperature detecting portions 3a and 6a. It is characterized in that it is possible to automatically measure the degree of progress of aging of the heater chip based on this detection information.
And the thickness dimension adjustment area 1b of the main body 1 for eliminating the variation in the heating characteristic between the heater chips in the area between the energizing terminal part 1a and the part b separated from the heating pressure contact part 2 by a predetermined distance. It is also characterized.
Further, a step 7 is provided along the boundary line between the energizing terminal portion 1a and the thickness dimension adjusting area 1b so that the thickness of the thickness dimension adjusting area 1b is thinner than the thickness of the energizing terminal section 1a. It is also characterized.
Further, the present invention is characterized in that a metal thin film 8 having excellent conductivity is formed on the power connection surface of the energizing terminal portion 1a for contacting the chip mounting surface on the power source side by sputtering or the like.

The heater chip for wiring connection according to the present invention has practical features as listed below.
(A) The vicinity of the heated pressure contact portion that is ignited is oxidized with the passage of time, and the oxidation product is peeled off, and the thickness gradually decreases (see FIG. 2). For this reason, the energization resistance in the vicinity is gradually increased.
(B) Therefore, the auxiliary temperature sensor temperature detector is placed at a predetermined distance from the temperature detector of the temperature sensor for temperature detection at the heating and pressure contact portion, and the change with time in the temperature gradient between the two temperature detectors is detected. By doing so, it is possible to automatically detect the degree of aging of the heater chip over time, and hence the renewal time.
( C ) When the main body of the heater chip is manufactured by a forging method, an irregular laminated structure is generated. Therefore, the delamination phenomenon is likely to occur in a portion that is repeatedly heated and cooled, which is one factor for shortening the life of the heater chip.
( D ) Therefore, the adjustment processing of the thickness of the main body, which is performed to eliminate the variation in the heat generation characteristics between the individual heater chips, is performed from the energizing terminal portion and the heating pressure contact portion, which do not cause a high temperature. If it is limited to the area between the parts separated by a distance, inconveniences such as promoting the delamination phenomenon can be avoided.
( E ) If the step is provided along the boundary line between the energization terminal portion and the thickness dimension adjustment area, the distance between the front end of the energization terminal portion and the heating pressure contact portion can be accurately determined. This also eliminates variations in heat generation characteristics between individual heater chips.
( F ) By forming a metal thin film having excellent conductivity on the current-carrying terminal part for contact with the chip mounting surface on the power supply side by sputtering or the like, the unevenness on the surface of the current-carrying terminal part is filled. The energization resistance on the mounting surface can be significantly reduced.
( G ) Therefore, the variation in the heat generation characteristics between the heater chips, which is derived from the variation of the energization resistance between the individual heater chips, is significantly reduced.

The specific configuration of the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view of a heater chip A1 as an embodiment of the present invention.
FIG. 2 is an explanatory diagram in which the portion S in the vicinity of the heating pressure contact portion 2 of the heater chip A1 is gradually oxidized by continuing to be ignited, and the oxide is peeled off and the thickness is gradually reduced.

First, the configuration of the heater chip A1 will be described with reference to FIG.
The heater chip A1 of this embodiment has a thin metal plate piece having a planar shape similar to that of a “shogi piece” as the main body 1.
The size of the main body 1 is about 15 × 17 millimeters in this embodiment.
The main body 1 of this embodiment is made by forging a tungsten-based alloy, and therefore, an irregular laminated structure is formed in the thickness direction (see FIG. 4).

In the middle of the front end portion of the main body 1 whose lateral width is narrowed in a trapezoidal shape, a small protrusion-like heating pressure contact portion 2 that generates heat due to an energization resistance is integrally projected.
In addition, a cut a is formed in a cut shape from the central portion on the base end side of the main body 1 toward the vicinity of the heating and pressing portion 2.
Each of the left and right side portions of the cut line a is a current-carrying terminal portion 1a, and this terminal portion also functions as a mounting portion for the heater chip A1. Reference numeral 10 denotes a mounting hole.

  A substantially triangular cut extension 11 is provided on the tip side of the cut a. On the inner wall surface on the distal end side of the cut extension portion 11, a heat welding protrusion 4 for attaching the temperature detecting portion 3 a of the temperature sensor 3 for temperature detection of the heating pressure welding portion 2 is integrated with an arrangement facing the heating pressure welding portion 2. It protrudes to. The temperature sensor 3 of this embodiment is a thermocouple.

The thermocouple 3 is composed of a combination of two conducting wires having different physical properties, for example, a chromel wire and an alumel wire, and the temperature detecting portion 3a is formed by thermally fusing the tip portions thereof. .
This thermocouple 3 is used for feedback control so that the temperature at which the heat-pressing portion 2 generates heat due to the energization resistance as the main body 1 is energized is maintained at an optimum temperature for each work (not shown). belongs to.

Furthermore, an auxiliary projection 5 is provided on the inner wall surface on the distal end side of the cut extension 11 at a position spaced apart from the hot welding projection 4 by a predetermined distance.
A temperature detecting portion 6a of a thermocouple 6 serving as an auxiliary temperature sensor is thermally welded to the auxiliary protrusion portion 5.

  As will be described later, the thermocouple 6 has a temperature gradient of the main body 1 between the thermometers 3a and 6a of the pair of thermocouples 3 and 6, with the aging of the heater chip A1, This is for detecting the degree of gradual change.

  The protrusions 4 and 5 for hot welding of the temperature measuring parts 3a and 6a are protruded from the inner wall surface of the cut extension part 11 as described above. This is to avoid adversely affecting the temperature measuring sections 3a and 6a.

Next, the operation of the heater chip A1 will be described.
Although not shown in the drawing, the left and right set of plate-like energizing terminal portions 1a and 1a of the heater chip A1 are in contact with the chip mounting surface provided on the heating power supply side. It is fixed by a mounting bolt inserted through the.

  The temperature of the heating and press-contact portion 2 that generates heat due to energization of the main body 1 is detected as an electromotive force value of the temperature detecting portion 3a of the thermocouple 3, and based on this detection signal, an energization control circuit provided in the power supply portion is Feedback control is performed so as to keep the heat generation temperature of the heating pressure contact portion 2 at a predetermined value.

By the way, as shown in FIG. 2 described above, the portion S of the main body 1 in the vicinity of the heating pressure contact portion 2 is gradually oxidized by continuing to be ignited, and the thickness is gradually reduced by peeling off of the generated oxide. (See b in FIG. 2).
Thus, the degree of such a wall thickness reduction would come out of use as a barometer of the aging degree of progress of the heater chip A1.

In other words, as the thickness of the portion S in the vicinity of the heating pressure contact portion 2 decreases, the electrical resistance in this portion increases, and accordingly, the degree of heat generation in the portion S gradually increases.
Therefore, as understood from FIG. 1, the temperature gradient between the temperature detection unit 3 a of the thermocouple 3 for temperature detection of the heating pressure welding unit 2 and the temperature detection unit 6 a of the thermocouple 6 as an auxiliary temperature sensor is It will change as the heater chip A1 ages.

  Therefore, by continuously checking the change in temperature gradient between the temperature measuring units 3a and 6a with time, the degree of aging of the heater chip A1 over time, and hence the renewal time, can be automatically detected. I can do it.

Next, the configuration and function of the heater chip A2 as another embodiment of the present invention will be described with reference to FIGS.
This heater chip A2 has the form shown as a perspective view in FIG.

The first feature in the form of the heater chip A2 is that the area between the energizing terminal portion 1a and the portion b separated from the heating pressure contact portion 2 by a predetermined distance is defined as the thickness dimension adjustment region 1b of the heater chip A2. It is in.
The purpose of this dimension adjustment is to eliminate variations in heat generation characteristics between the individual heater chips A2.

The second feature is that a step 7 is provided along the boundary line between the plate-shaped energizing terminal portion 1a and the thickness dimension adjusting area 1b, and the thickness of the thickness dimension adjusting area 1b is set to be for energization. It is in the place made thinner than the thickness of the terminal part 1a.
In FIG. 3, illustration of the thermocouples 3 and 6 is omitted.

  Furthermore, as a third feature, a metal thin film 8 having excellent conductivity, such as a metal, is provided on the contact surface of the current-carrying terminal portion 1a, which is in contact with a power source chip mounting surface (not shown) serving as a heating source. A coating layer made of copper is formed by sputtering or the like.

Next, the characteristic operation of the heater chip A2 will be described.
The most important function required for the heater chip is that the wiring connection to each electrode is always performed uniformly and reliably in a good state.

For that purpose, first, it is necessary that the dimensional accuracy of each part of the main body 1 does not vary between the individual heater chips A2.
Even if the thickness of the main body 1 varies by as little as 0.1 millimeter, the heat generation temperature of the heating and pressure-bonding portion 2 may be unacceptably large.

In order to eliminate such variation in the heat generation characteristics, a thickness adjustment process for finely adjusting the thickness dimension of the main body 1 is required.
In this case, as already mentioned at the beginning, when the main body 1 is made by the forging method, an irregular laminated structure is formed in the thickness direction as shown in FIG. Is a point.

In the vicinity of the heating pressure contact portion 2, the strong heat and the cooling are repeated, so that they frequently expand and contract, and accordingly, a peeling phenomenon starts to occur between the layers of the irregular laminated structure.
As the peeling phenomenon progresses, the heat generation characteristics naturally change.

  When a thickness adjustment process is performed on a portion having an irregular laminated structure where the delamination phenomenon is likely to occur, it is derived from the residual stress contained in the laminated structure, and as shown in FIG. This promotes the tendency of peeling (see reference symbol G in FIG. 4) that occurs when scraping with a plane in the direction of “opposite eye”.

Therefore, the thickness adjusting process of the body 1 has passed distance from the area heated strong, energizing terminal portions 1a, region between the heating contact portion 2 with a predetermined distance between each point b, that is, the thickness dimension adjustment range This is limited to 1b (see FIG. 3).

In this way, the thickness dimension adjustment range 1b, if Hodokose the thickness adjusting process, necessarily, the thickness dimension adjustment range 1b, so that the step 7 occurs along the boundary line between the energizing terminal portions 1a .

The step 7, of the main body 1, only the portion of the energizing terminal portions 1a, reliably brought into contact with the chip mounting surface of the power supply side, the first from the front end of the energizing terminal portions 1a, the thickness dimension adjustment range The portion that reaches the heating and press-contact portion 2 through 1b plays an extremely useful role of ensuring that the portion is not brought into contact with the chip mounting surface on the power source side.

  As a result, the distance between the front end of the energizing terminal portion 1a and the heating pressure contact portion 2 can be reliably determined to be a predetermined dimension in a state where the heater chip A2 is completely attached to the power source side chip mounting surface. This also eliminates variation in the heat generation characteristics between the individual heater chips A2.

  Next, regarding the effect obtained by forming the metal thin film 8 having excellent conductivity on the contact surface of the current-carrying terminal portion 1a to be contacted with the chip mounting portion on the power source side by sputtering or the like, By processing, fine irregularities on the surface of the energizing terminal portion 1a can be compensated.

As a result, the degree of adhesion of the contact surface of the energizing terminal portion 1a to the chip mounting portion (surface) on the power source side is greatly increased, and the energization resistance of the contact surface can be significantly reduced.
Therefore, the degree to which the energization resistance of the mounting portion varies between individual heater chips is reduced, which contributes to a significant reduction in variation in heat generation characteristics between the heater chips.

1 is a perspective view of a heater chip according to an embodiment of the present invention. In the same manner, the vicinity of the heating pressure contact portion is oxidized with time, and the thickness of the main body gradually decreases at this portion. FIG. 5 is a perspective view of a heater chip according to another embodiment of the present invention. It is the fragmentary longitudinal cross-section which showed that the main body made by the forging method was equipped with the irregular laminated structure in the thickness direction.

Explanation of symbols

A1, A2 Heater chip 1 Body 1a Current-carrying terminal 1b Thickness dimension adjustment area 2 Heating pressure contact 3 Thermocouple (temperature sensor)
3a Temperature detector 4 Hot welding protrusion 5 Auxiliary protrusion 6 Thermocouple (Auxiliary temperature sensor)
6a Temperature detection part 7 Step 8 Metal thin film 10 Mounting hole 11 Cut extension part S Location near heating pressure contact part a Cut b Location separated by a predetermined distance

Claims (4)

A small protrusion-like heating pressure contact portion 2 that generates heat due to an energizing resistance is provided on the distal end side of the main body 1 made of a metal plate piece, and a cut line a is formed from the central portion on the base end side toward the vicinity of the heating pressure contact portion 2. Provided with a notch shape, each of the both sides of the cut a is a current-carrying terminal portion 1a, and has a configuration in which a temperature sensor for temperature detection is attached in the vicinity of the heating pressure contact portion 2.
A temperature measuring unit 6a of the auxiliary temperature sensor 6 is provided at a position spaced apart from the temperature measuring unit 3a of the temperature sensor 3 for temperature detection of the heating pressure welding unit 2,
As the oxidation phenomenon of the main body 1 progresses in the vicinity S of the heated pressure welding portion 2 that is ignited, the degree to which the temperature distribution of the vicinity S changes with time is determined between the two temperature detecting portions 3a and 6a. A heater chip for wiring connection, which is detected from a change over time in the detected temperature difference between them, and based on this detection information, the aging progress of the heater chip can be automatically measured.   A region between the energizing terminal portion 1a and a portion b separated from the heating pressure contact portion 2 by a predetermined distance is set as a thickness dimension adjustment region 1b of the main body 1 for eliminating variation in heating characteristics between the heater chips. The heater chip for wiring connection according to claim 1. Step 7 is provided along the boundary line between the energizing terminal portion 1a and the thickness dimension adjusting area 1b, and the thickness of the thickness dimension adjusting area 1b is made thinner than the thickness of the energizing terminal section 1a. The heater chip for wiring connection according to claim 2, wherein: The metal thin film 8 having excellent conductivity is formed on the power connection surface of the energizing terminal portion 1a for contacting the chip mounting surface on the power source side by sputtering or the like. The heater chip for wiring connection according to claim 3 .

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