JP2639994B2 - Pellet bonding equipment - Google Patents

Abstract

PURPOSE:To remove bubbles in layers of a solder foil and the like and prevent characteristic failure by causing a pellet to earth to a substrate or a lead frame after tilting its pellet and gradually making its angle of inclination small. CONSTITUTION:A collet 1 is allowed to attract a pellet 2 and to place its pellet on an upper part of a frame 3 on which the pellet 2 is mounted in a state that a bonding arm 4 is held in the horizontal position. Once a movable block 7 comes down by the rotation of a motor 11, a supporting shaft 6 comes down and the pellet 2 which is attracted to the collet 1 abuts on the frame 3 where a silver paste and so on are attached in a state that the pellet has an inclination of only an angle theta. If the block 7 comes down, the arm 4 rotates clockwise by taking the supporting shaft 6 as a supporting point and the pellet 2 gradually decreases its inclination. The pellet 2 is thus stuck fast to the frame horizontally while expelling bubbles in the silver paste and then characteristic failure decreases.

Description

The present invention relates to a pellet bonding apparatus for bonding a pellet to a substrate or a lead frame using a collet for adsorbing the pellet.

(B) Conventional technology This type of pellet bonding apparatus is disclosed in Japanese Patent Application Laid-Open No. 57-2703.
No. 8 discloses this.

According to this, the collet that has absorbed the pellets moves up and down, and after bonding the pellets horizontally to the substrate or lead frame, performs a scrub (rubbing) operation.

(C) Problems to be Solved by the Invention However, in the conventional technique, air bubbles in a layer of a solder foil, a gold foil or a silver paste on a substrate or a lead frame cannot be reliably eliminated. There is a drawback that heat conduction to the lead frame is deteriorated, which causes poor characteristics of the semiconductor element.

Accordingly, an object of the present invention is to prevent the occurrence of poor characteristics due to poor heat conduction by reliably removing the air bubbles.

(D) Means for Solving the Problems To solve the problem, the present invention provides a pellet bonding apparatus for bonding a pellet to a substrate or a lead frame by using a collet for adsorbing the pellet. And a second mechanism for reducing the inclination angle of the pellet with respect to the grounded surface and mounting the pellet on a substrate or a lead frame.

The present invention also provides a pellet bonding apparatus for bonding a pellet to a substrate or a lead frame by using a collet for adsorbing the pellet, wherein the lifting member which moves up and down, and the collet is provided at one end and is supported by the lifting member. A rotating member, means for rotating the rotating member in a direction in which the pellet adsorbed by the collet comes into contact with the substrate or the lead frame, and a state in which the elevating member is lowered and the pellet is inclined to the substrate or the lead frame. A regulating member that regulates the rotation of the rotating member so as to abut and releases the regulation after the abutment, and the elevating member further descends even after the pellet abuts on the substrate or the lead frame in an inclined state. Thus, the rotating member is rotated, and as a result, the pellet is rotated and bonded.

(E) Action According to the configuration of claim 1, the pellet is tilted by the first mechanism to be grounded to the substrate or the lead frame, and the pellet is tilted to the grounded surface by the second mechanism. At a reduced angle, the pellet is mounted on a substrate or lead frame.

According to the configuration of claim 2, when the lifting / lowering means descends, the rotation of the rotating member is restricted by the restricting member, and the pellet adsorbed by the collet provided at one end of the rotating member has a predetermined angle. It comes into contact with the substrate or lead frame at an angle. When the elevating member further descends, the regulating member releases the regulation of the rotation of the pivoting member, and the pivoting member pivots to rotate the pellet adsorbed by the collet to perform bonding.

(F) Example An example of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, (1) is a collet placed on a frame (3) on which a silver paste is adhered by vacuum-adsorbing a pellet (2), and (4) is a collet at one end. A bonding arm having (1) and a cam follower (5) mounted on the other end, and pivots around a support shaft (6) attached in the middle of the arm.

(7) is a movable block on which the support shaft is mounted,
It is attached to a nut (8) fitted to the ball screw (9), and moves with the movement of the nut (8) in the vertical direction while being guided by a guide block (not shown).

The ball screw (9) is vertically mounted on the bonding body (10) and rotates forward and reverse by a motor (11), whereby the nut (8) moves up and down and the movable block (7) also moves up and down. . The bonding main body (10) is placed on an XY table (not shown) and can move in the horizontal direction.

(12) is a spring stretched between the bonding arm (4) and the bonding pressure adjusting screw (13) screwed to the movable block (7), in a direction in which the collet (1) descends. Urges the bonding arm (4) to rotate. The bonding pressure adjusting screw (13) can adjust the pressing force applied to the pellet (2) at the time of bonding by adjusting the urging force of the spring (12).

(14) is a movable stopper driven by a solenoid (not shown) fitted in the movable block (7) so as to be able to move up and down, and at a lower limit position against a biasing force of a spring (12).
The bonding arm (4) is engaged and held horizontally.

(15) is a fixed guide fixed to a position where it does not move with respect to the pellet supply unit (16) and the frame (3). When the bonding body (10) moves on an XY table (not shown) to move it to the top,
The cam follower (5) moves while contacting the lower surface, but has a lower surface that is inclined so that the cam follower (5) gradually moves upward while moving. The fixing guide (15) is also connected to the bonding arm (4) via the cam follower (5).
The rotation by the spring (12) of the movable block (7) is restricted.
Descends and the pellets (2) adsorbed on the collet (1)
However, when the bonding arm (4) is in contact with the frame (3), the pellet (2) is also inclined at a predetermined angle θ because the bonding arm (4) is inclined at a predetermined angle θ with respect to the frame (3).

In FIG. 3, reference numeral (16) denotes a pellet supply section for supplying pellets (2) to the collet (1).

The operation of the above configuration will be described below.

The bonding body (1
0) moves, collet (1) is pellet feeder (16)
Is located directly above. At this time, since the movable stopper (14) is lowered to the lower limit, the bonding arm (4) is horizontal, and the pellet suction surface of the collet (1) is also horizontal.

When the motor (11) rotates, the movable block (7) attached to the nut (8) is lowered via the ball screw (9), and the collet (1) keeps its suction surface horizontal. It descends and adsorbs the pellet (2) placed on the pellet supply section (16). Then the motor (1
1) rotates reversely and passes through the state shown in FIG. 3, and the movable block (7) rises until the cam follower (5) comes into contact with the fixed guide (15). Then movable stopper (14)
Is raised to the upper limit by the solenoid.

The bonding body (10) is horizontally moved by an XY table (not shown), and the collet (1) is located on the upper part of the frame (3) on which the pellet (2) is mounted as shown in FIG. At this time, the cam follower (5) is fixed guide (15)
The bonding arm (4) moves while contacting the inclined lower surface, and is turned counterclockwise to be in an inclined state.

Here, when the movable block (7) is lowered by rotation of the motor (11), the support shaft (6) itself is also lowered, so that the bonding arm (4) applies the urging force of the spring (12) about the support shaft (6) as a fulcrum. As a result, it rotates counterclockwise in FIG. When the movable block (7) descends by the distance A, as shown in FIGS. 2 and 5, the pellet (2) adsorbed on the collet (1) has the silver paste attached thereto in a state of being inclined by the inclination angle θ. Abuts frame (3).

When the movable block (7) further descends, the cam follower (5) separates from the fixed guide (15), and the pellet (2)
Is restricted by the frame surface, so that the bonding arm (4) rotates clockwise in FIG. 5 around the support shaft (6). For this reason, the inclination of the pellet (2) adsorbed on the collet (1) also gradually decreases. Thus, the pellets (2) become horizontal while expelling bubbles in the silver paste.

When the pellet (2) is horizontal, the motor (1
1) The rotation stops and the movable block (7) stops. Then, the movable stopper (14) descends to the lower limit and contacts the bonding arm (4). Thereafter, the pellet (3) is scrubbed by the horizontal movement of the XY table.

In the above embodiment, the same operation is performed even when the silver paste on the frame (3) is a gold foil or a solder foil, or when a substrate is used instead of the frame (3).

In addition, the vertical movement of the movable stopper (14) is stopped at a predetermined position instead of the fixed guide (15), whereby the rotation of the bonding arm (4) is restricted and the pellet (2) is stopped.
Can be tilted at a predetermined angle to make contact with the frame (3).

Further, even if the frame (3) or the substrate is not placed horizontally, the pellet (2) can be bonded to the frame (3) or the substrate by the same operation.

(G) Effects of the Invention As described above, the present invention can reliably eliminate bubbles in a layer of a solder foil, a gold foil, a silver paste, or the like on a substrate or a lead frame at the time of bonding, and can prevent the occurrence of poor characteristics. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a pellet bonding apparatus to which the present invention is applied, FIG. 2 is an enlarged side view of the vicinity of a collet tip at the moment when the pellet comes into contact with a frame, and FIG. FIG. 4 is a side view showing a state immediately after the pellets are adsorbed, FIG. 4 is a side view showing a state where the collet that has adsorbed the pellets is at the top of the frame, FIG. FIG. 6 is a side view showing a state at the moment when the pellet is mounted on the frame. (1) Collet (2) Pellets (3)
Frame (4) Bonding arm (6)
Support shaft, (7) ... movable block, (12) ... spring, (1
5) …… Fixed guide.

Claims (2)

(57) [Claims] In a pellet bonding apparatus for bonding a pellet to a substrate or a lead frame by using a collet for adsorbing the pellet, a first mechanism for inclining the pellet to ground the substrate or the lead frame,
A second mechanism for mounting the pellet on a substrate or a lead frame by reducing the angle of inclination of the pellet grounded in an inclined state with respect to the grounded surface by the first mechanism and mounting the pellet on a substrate or a lead frame. Pellet bonding equipment. 2. A pellet bonding apparatus for bonding a pellet to a substrate or a lead frame by using a collet for adsorbing the pellet, wherein the lifting member moves up and down, and the collet is provided at one end and is supported by the lifting member. A rotating member, means for rotating the rotating member in a direction in which the pellet adsorbed by the collet comes into contact with the substrate or the lead frame, and a state in which the elevating member is lowered and the pellet is inclined to the substrate or the lead frame. A regulating member that regulates the rotation of the rotating member so as to abut and releases the regulation after the abutment, and further lowers the elevating member even after the pellet abuts on the substrate or the lead frame in an inclined state. The pellet bonding apparatus is characterized in that the rotating member is rotated to thereby rotate the pellet and, as a result, the pellet is rotated and bonded.