JPH0227580Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a bonding device that places lead terminals of electronic components on lands of a printed circuit board and solders the lead terminals by lowering a bonding tape.

Place the lead terminals of electronic components such as LSIs to be soldered on the lands of the printed board, heat them with bonding tape, and solder the lead terminals to the designated lands. A bonding apparatus shown in the configuration diagram of FIG. 2 is used.

The printed board 2 is mounted on the table 1, and the table 1 is transferred by the table transfer section 6 in the arrow X direction and the arrow Y direction. The elevating mechanism 4, which is raised or lowered relative to the upper surface of the printed board 2, is driven in the direction of arrow Z by the elevating drive section 7. Further, the table transfer section 6 and the lifting/lowering drive section 7 are configured to be controlled by a control section 8.

Therefore, by moving the table 1, the part to be soldered is positioned directly below the bonding tape 5 that is locked to the lifting mechanism 4, and the lifting mechanism 4 moves in the direction of the arrow Z.
By being lowered in the direction, the lead terminals protruding on both sides of the semiconductor element 3 mounted on the printed board 2 are pressed against predetermined lands, and the lead terminals are soldered by heating.

In order to obtain such reliability of soldering, the bonding tab 5 is lowered by the lifting mechanism 4.
It is important that the tip of the bonding tape 5 be reliably positioned so as to press the solder surface of the lead terminal when it comes into contact with the lead terminal.

[Conventional technology]

Conventionally, such bonding has been formed as shown in the side view of FIG. a, b, c, d
The figures are side views sequentially explaining the lowering operation of the bonding tape.

As shown in Fig. a, the bonding tape 5 held by the tape holders 9A and 9B in which the spring 10 is installed is lowered by the lowering of the lifting mechanism 4.
The printed board 2 is lowered in the direction of arrow Z so as to be located at a position where the lead terminals 3A of the semiconductor element 3 provided with the fins 3B are overlapped on a predetermined land.

As shown in figure b, this descent is such that the tip of the bonding tape 5 is approximately 1/2 the height H of the lead terminal 3A.
The process is carried out until the position is at an interval of .

Next, the tape holders 9A and 9B are moved in the direction of arrow A so that the tip of the bonding tape 5 clamps the lead terminal 3A as shown in FIG.
In this narrowed state, the bonding tape 5 is further lowered in the direction of arrow Z, and the tip of the bonding tape 5 presses the solder surface of the lead terminal 3A due to the spring pressure of the spring 10.

By guiding the bonding tape 5 along the side surface of the lead terminal 3A in this manner, consideration is given to ensuring that the tip of the bonding tape 5 is positioned at the soldering location.

[Problem that the invention attempts to solve]

However, such a printed board 2 actually has distortions and warps, and even when mounted on the table 1, the surface of the printed board 2 on which the lands 2A are provided becomes wavy.

Therefore, even if the elevating mechanism 4 lowers the bonding tape 5 by a predetermined amount, the distal end portions of the bonding tape 5 cannot be positioned at a distance of H/2 as described above. Therefore, if the gap is large, use the tape holders 9A and 9B as shown in the detailed view of the main part in Figure 4a.
During clamping, the tip of the bonding tape 5 hits the protrusion of the lead terminal 3A, making it impossible to press the solder surface with the land 2A. In addition, if the gap is small, as shown in the detailed view of the main part in figure b, when the tape holders 9A and 9B are clamped, the bonding tape 5
Since the tip of the lead terminal 3A touches the tip of the lead terminal 3A, the solder surface cannot be pressed against the land 2A as described above.

Therefore, in either case, there is a problem in that the lead terminal 3A is not soldered to the land 2A.

[Means for solving problems]

The above-mentioned problem is that the elevating mechanism includes a slide rod that comes into contact with the top surface of the electronic component as the elevating mechanism descends and slides up and down within the elevating mechanism; and a sensor for detecting the displacement of the electronic component, and the lifting mechanism is configured to be stopped at a position where the tape reaches a desired height from the top surface of the electronic component by controlling the lifting drive unit based on the output signal of the sensor. The problem is solved by the invented bonding device.

[Effect]

That is, when the elevating mechanism is lowered, the member contacts the electronic component, and by detecting the contact position using the sensor detector, the actual distance between the tip of the bonding tape and the surface of the printed board can be determined. be judged.

Therefore, an accurate spacing can be obtained without causing excessive or insufficient lowering due to warpage of the printed board as in the conventional case.

〔Example〕

The present invention will be explained in detail below with reference to an embodiment shown in FIG. Figures a, b ₁ and b ₂ are side views.

Note that the same reference numerals indicate the same objects throughout the figures.
As shown in FIG. A guide bar 11 that is slid in the P direction and a sensor 12 that detects the sliding of the guide bar 11 are provided, and the signal of the sensor 12 is transmitted as an output signal S to the above-mentioned lifting drive section 6 via a detection circuit 13. This is what I did.

With this configuration, as shown in Figure _b1 , the tape holders 9C and 9D are first lowered by the slide rod 1.
1 until one end of the fin 3B is brought into contact with the fin 3B and the other end is located on the sensor 12, and then lowered by a predetermined amount. In this way, even if the printed board 2 is warped, the distance S ₁ between the tips of the bonding tape 5 can always be kept at a predetermined value due to the lowering of the tip, making it possible to obtain a predetermined spacing of H/2. can.

Furthermore, the predetermined spacing can be similarly obtained by performing the process as shown in Fig. _b2 . First, the difference t when the guide rod 11 passes the sensor 12 after descending by a predetermined amount is determined.
is detected by the descending speed, and then the interval is determined by finely adjusting the height and lowering so that this difference t becomes a predetermined value.
S ₂ can be performed at predetermined intervals.

Therefore, the distance between the tip of the bonding tape 5 and the surface of the printed circuit board 2 can be determined by detecting the position of the slide rod 11 that comes into contact with the fin 3B of the semiconductor element 3 when it is lowered. Even if there is warpage of printed board 2,
The tips of the bonding tape 5 can be positioned at predetermined intervals.

Therefore, it is possible to prevent excessive or insufficient descent as in the conventional case.

[Effect of idea]

As explained above, the present invention positions the tip of the bonding tape and the surface of the printed circuit board at a predetermined distance using the slide rod that comes into contact with the semiconductor element to be soldered when the bonding tape is lowered. , the bonding tape reliably presses the solder surface of the lead terminal.

This prevents soldering defects caused by warping of conventional printed circuit boards and ensures reliable soldering, which has great practical effects.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, in which a, b ₁ , b ₂
The figure shows a side view, FIG. 2 shows a configuration of the bonding apparatus, FIG. 3 shows a conventional side view, and FIG. 4 shows a detailed view of the main parts. In the figure, 1 is a table, 2 is a printed board, 3 is a semiconductor element, 4 is a lifting mechanism, 5 is a bonding tape, 6 is a lifting drive unit, 7 is a table transfer unit, 8 is a control unit, 9A, 9B, 9C , 9D is a tape holder, 10 is a spring, 11 is a slide rod, 12 is a sensor, and 13 is a detection circuit.

Claims (1)

[Claims for Utility Model Registration] A table on which a printed board is mounted, a tape that heats and presses the leads of electronic components placed on the printed board, an elevating mechanism that holds the tape and raises and lowers it; A bonding device for soldering the electronic component to the printed circuit board, the device having an elevating drive unit that drives an elevating mechanism, the elevating mechanism having an elevating mechanism that comes into contact with the upper surface of the electronic component by lowering the elevating mechanism. A slide rod that slides up and down within the elevating mechanism and a sensor that is fixed to the elevating mechanism and detects displacement of the slide rod with respect to the elevating mechanism are attached, and the elevating drive section is controlled by an output signal of the sensor. A bonding apparatus characterized in that the elevating mechanism is configured to stop at a position where the tape reaches a desired height from the top surface of the electronic component.