KR101165030B1 - Chip Bonder - Google Patents

Abstract

The present invention discloses a chip bonder. The disclosed chip bonder includes a first unit capable of tilting front and rear, left and right, and having a substrate seated on an upper surface thereof; And a second unit positioned directly above the first unit, the second unit absorbing and transferring the semiconductor chip and bonding the semiconductor chip to the substrate.

According to the present invention, the laser beam irradiation unit is provided in the bonding head, and the front, rear, left and right tilting blocks (rotating structure) are installed in the stage, thereby effectively preventing the deterioration of the bonding quality due to mechanical thermal deformation.

In addition, a load cell (load sensor) that senses a change in pressure of the bonding head is installed on the stage side, so that a reliable bonding operation can be performed by precisely controlling the contact force.

In addition, by reducing the weight of the bonding head, the motion of the bonding head can be accelerated to improve productivity, and the cost reduction can be realized by eliminating excessively mounted cooling devices by isolating the high temperature heater.

Chip Bonder, Laser Beam, Tilting Control Block

Description

Chip Bonder

The present invention relates to a chip bonder, and more particularly, to a chip bonder capable of maintaining a parallelism maintaining structure of a bonding head and a stage and precise pressure sensing control.

In general, among the various mounting methods of the semiconductor package, in recent years, as semiconductor products become smaller and more integrated, semiconductor chips become increasingly high-performance, and thus the number of pins is increased. However, the technology of narrowing the distance between the pins (pad pitch) Is asking. Flip Chip Bonding was developed to meet these technical needs.

In this flip chip bonding method, an anisotropic conductive film (ACF) or an anisotropic conductive adhesive (ACA) is used as an adhesive that bonds a semiconductor chip and a substrate and prevents foreign substances from penetrating. Adhesive) or NCP (Non Conductive Polymer) is widely used.

As such, when bonding two media using ACF, ACP or NCP, a method of thermal fusion is used while applying pressure by giving a constant temperature, pressure, and time due to the nature of the bonding medium.

The method of heating the medium at a constant temperature includes a method using a device equipped with a hot bar equipped with a heater (thermal compression method), a method of using friction heat of a contact part using ultrasonic waves (ultrasound method), and a method using a laser (laser method). And the like can be used.

In particular, the laser method is the most widely used method because it has advantages over other methods in terms of performance and efficiency.

The chip bonder used for attaching the chip to the substrate has an adsorption mechanism capable of adsorbing the chip on the head transported by the transfer mechanism. When mainly used.

When the chip is adhered to the substrate, if the surface of the chip is not uniformly adhered to the upper surface of the substrate, poor contact may occur between the chip and the circuit of the substrate, so the bottom surface of the head and the upper surface of the stage should be parallel. However, such a chip bonder is constructed by assembling a large number of mechanical parts. Therefore, when operating for a long time, the bonding head and the stage are not completely parallel and are inclined due to play or error between the mechanical parts. Occurs. Accordingly, the chip bonder head inclines the angle of the chip adsorbed by the suction mechanism to a predetermined angle in accordance with the curved surface of the substrate, thereby preventing contact defects between the circuit printed on the substrate and the chip.

In general, in the case of bonding a medium, a method of thermally fusion is used while pressing to give a constant temperature, pressure, and time due to the characteristics of the medium to bond. To this end, a bonding head that moves up and down from the top presses a chip.

As the lead pitch of the chip is lowered, the pressing surface of the bonding head and the surface of the stage supporting the substrate should always be horizontal to bond at low pressure.

Conventionally, the bonding head is equipped with a rotating structure capable of adjusting the horizontal degree and a load cell (load sensor) capable of measuring pressure to press the semiconductor chip and the substrate to a predetermined pressure and apply bonding at a high temperature. .

In this bonding method, the bonding head is transferred at a high speed until the initial contact state between the semiconductor chip and the substrate, and the pressure is maintained at a low speed from the moment of contact.

At this time, the bonding head is transferred while checking a change in pressure transmitted from the load cell. As shown in FIG. 1, a constant pressure, that is, a contact force, is used for a user to determine a contact state between a semiconductor chip and a substrate. Should be set. As described above, as the lead pitch of the chip is lowered, in order to bond at a low pressure, the contact force set by the user must be precisely controlled.

However, in the conventional chip bonder, since the load cell is provided in the bonding head, a minute signal change occurs due to the noise caused by the motion of the bonding head, resulting in confusion with the contact force signal, making it difficult to perform a reliable bonding operation.

In addition, the heater heated to about 300 ~ 400 ℃ is mounted on the bonding head side, causing a thermal deformation of the precisely adjusted horizontal adjustment mechanism (rotational structure), causing a problem of lowering the bonding quality.

The present invention has been made to solve the above problems, the laser beam irradiation unit is installed in the bonding head, the front, rear, left and right tilting block is installed on the stage, it can effectively prevent the deterioration of the bonding quality due to mechanical thermal deformation. The purpose is to provide a chip bonder.

Another object of the present invention is to provide a chip bonder capable of precisely controlling a contact force by installing a load cell detecting a change in pressure of a bonding head on a stage.

  It is still another object of the present invention to provide a chip bonder capable of reducing the weight of the bonding head to improve the productivity by moving the bonding head more quickly.

In order to achieve the above object, the chip bonder of the present invention is capable of tilting forward and backward, left and right, and includes: a first unit on which a substrate is mounted; And a second unit positioned directly above the first unit and having a laser beam irradiator so as to adsorb, transfer, and bond the semiconductor chip to the substrate.

The first unit includes a base block; A left and right tilting control block mounted on the top of the base block in a tiltable direction in a left and right direction; Left and right tilting control unit for adjusting the tilting of the left and right tilting control block; A front and rear direction tilting control block mounted on the top of the left and right tilting control block so as to be tiltable in the front and rear directions; Front and rear tilting control unit for adjusting the tilting of the front and rear tilting control block; Locking unit for fixing the tilting of the front and rear left and right tilting control block; And a stage on which the substrate is seated.

A load cell bracket having a load cell is provided below the stage.

An anti-rotation protrusion is formed on an upper surface of the load cell bracket, and an anti-rotation groove corresponding to the anti-rotation protrusion is formed on a lower surface of the stage.

The left and right tilting control block and the front and rear tilting control block is composed of a fixed block and a tilting block which is installed to be tilted in the left and right direction with respect to the fixed block, the guide rail is formed on the upper surface of the fixed block and correspondingly Guide grooves are formed on the lower surface of the tilting block.

The left and right tilting control unit and the front and rear tilting control unit is fixed to one side of the fixing block; A movable bracket fixed to one side of the tilting block; A tightening bolt fixed to one side of the fixing bracket to move the movable bracket; An elastic member installed at the other side of the fixing bracket to support the movable bracket; And a support bolt for supporting the elastic member. The stage is characterized in that the heater block.

The second unit may further include: a head block for sucking up and lifting a semiconductor chip on a lower surface thereof; And a laser beam irradiation unit disposed above the head block to bond the semiconductor chip to the substrate.

As described above, the laser beam irradiation unit is installed in the bonding head, and the front, rear, left and right tilting blocks (rotating structures) are separately installed in the stage, thereby effectively preventing the deterioration of the bonding quality due to mechanical thermal deformation.

In addition, a load cell that senses a change in pressure of the bonding head is installed on the stage side, so that a reliable bonding operation can be performed by precisely controlling the contact force.

In addition, by reducing the weight of the bonding head, the motion of the bonding head can be accelerated to improve productivity, and the cost reduction can be realized by eliminating excessively mounted cooling devices by isolating the high temperature heater.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

Figure 2 is a perspective view showing a chip bonder of the present invention, Figure 3 is an exploded perspective view showing a first unit in the chip bonder of the present invention, Figures 4 and 5 are left and right tilt adjustment in the first unit of the present invention 6 and 7 are side views illustrating front and rear tilt adjustment in the first unit of the present invention.

As shown in Figures 2 to 7, the chip bonder of the present invention is tiltable adjustable in the front and rear, left and right directions, the first unit 100 is seated on the upper surface; And a second unit 200 positioned above the first unit 100 and having a laser beam irradiation unit 220 so as to adsorb, transfer, and bond the semiconductor chip to the substrate.

In the chip bonder of the present invention, the first unit 100 includes a base block 110 fixed to the ground. The upper side of the base block 110 is mounted to the left and right tilting control block 120 that can be tilted in the horizontal direction.

The left and right tilting adjustment block 120 is composed of a fixed block 121 and the tilting block 122 is installed to be tilted in the left and right direction with respect to the fixed block 121, the upper surface of the fixed block 121 The guide rail 121a is formed to protrude, and correspondingly, a guide groove 122a is formed on the bottom surface of the tilting block 122.

Chip bonder of the present invention is provided with a left and right tilting control unit 130 for adjusting the tilting (tilting) of the left and right tilting control block 120.

The left and right tilting adjustment unit 130 is a fixing bracket 131 fixed to one side of the fixing block 121; A movable bracket 132 fixed to one side of the tilting block 122; A fastening bolt 133 fixed to one side of the fixing bracket 131 to move the movable bracket 132; An elastic member 134 installed on the other side of the fixing bracket 131 to support the movable bracket 132; And a support bolt 135 supporting the elastic member 134. The support bolt 135 is also provided with an auxiliary spring 136 for elastically supporting the support bolt 135.

In addition, the front and rear direction tilting control block 140, which is capable of tilting forward and backward, is also mounted on the upper and left direction tilting control block 120.

The front and rear direction tilting control block 140 is composed of a fixed block 141 and a tilting block 142 which is installed to be tiltable in a left and right direction with respect to the fixed block 141, wherein the fixed block 141 A guide rail 141a protrudes from an upper surface thereof, and a guide groove 142a is formed on a lower surface of the tilting block 142 correspondingly.

Chip bonder of the present invention is provided with a forward and backward tilting control unit 150 for adjusting the tilting of the front and rear tilting control block 140.

The front and rear tilting adjustment unit 150 is a fixing bracket 151 fixed to one side of the fixing block 141; A movable bracket 152 fixed to one side of the tilting block 142; A fastening bolt 153 fixed to one side of the fixing bracket 151 to move the movable bracket 152; An elastic member 154 installed at the other side of the fixing bracket 151 to support the movable bracket 152; And a support bolt 155 for supporting the elastic member 154. An auxiliary spring 156 is also interposed in the support bolt 155.

Chip bonder of the present invention, the locking unit 160 for fixing the tilting of the front and rear, left and right tilting control block 120, 140; And a stage 170 on which the substrate B is seated.

The stage 170 serves to adsorptively fix and heat the substrate B, and a load cell bracket 180 having a load cell 181 is installed under the stage 170.

An anti-rotation protrusion 182 is formed on an upper surface of the load cell bracket 180, and an anti-rotation groove 171 corresponding to the anti-rotation protrusion 182 is formed on a lower surface of the stage 170.

The stage 170 is provided with a heat insulating part 173 for insulating the load cell 181.

In addition, the second unit 200 may include a head block 210 for absorbing and lifting a semiconductor chip on a lower surface thereof; And a laser beam irradiation unit 220 installed above the head block 210 to bond the semiconductor chip to the substrate B.

Referring to the operation of the chip bonder of the present invention configured as described above are as follows.

In a state where the substrate B is fixed on the stage 170 by adsorption, the head block 210 lowers the semiconductor chip (not shown) on its lower surface by adsorption.

When the semiconductor chip contacts the upper surface of the substrate B on which the adhesive (not shown) is applied at a constant pressure, the lazy beam irradiation unit 220 irradiates a laser beam to cure and bond the adhesive (not shown).

Here, when the semiconductor chip is seated on the substrate B, if the surface of the semiconductor chip is not uniformly bonded to the upper surface of the substrate B, poor contact may occur between the semiconductor chip and the circuit of the substrate B, The bottom surface of the head block 210 and the top surface of the stage 170 should always be parallel.

However, since the chip bonder is assembled with a large number of mechanical parts, the bonding head 210 and the stage 170 may not be completely parallel due to a gap or an error occurring between the mechanical parts when operating for a long time. In some cases, tilting may occur.

In this case, the front and rear, right and left tilting (tilt) of the stage 170 should be adjusted to prevent contact failure between the circuit printed on the substrate B and the semiconductor chip.

In the chip bonder of the present invention, the contact defect between the circuit printed on the substrate B and the semiconductor chip is effectively prevented in advance through the left and right tilting and the forward and backward tilting adjustment process.

First, when adjusting the left and right tilting, as shown in Figures 4 and 5, loosely loosen the support bolt 135 and then turn the tightening bolt 133 in the direction of the arrow, to the fixing bracket 131 The tightening bolt 133 is screwed forward to press the movable bracket 132.

At this time, in the state in which the elastic member (spring) 134 elastically supports the movable bracket 132, the movable bracket 132 is inclined while being slid, thereby adjusting the left and right tilting. The movable bracket 132 slides here because the guide rail 121a is coupled to the guide groove 122a.

On the other hand, when the tightening bolt 133 is turned in the opposite direction to the arrow, the tightening bolt 133 screwed to the fixing bracket 131 is reversed, and at this time, the movable bracket 132 by the elastic restoring force of the elastic member 134. In this elastically supported state, the movable bracket 132 is inclined to the opposite side, thereby adjusting the left and right tilting.

In the same principle, in the case of adjusting the tilting forward and backward, as shown in FIGS. 5 and 6, after loosening the support bolt 155 and turning the tightening bolt 153 in the direction of the arrow, the fixing bracket 151 The tightening bolt 153 is screwed to the () to advance the pressurizing the movable bracket 152.

At this time, in a state in which the elastic member (spring) 154 elastically supports the movable bracket 152, the movable bracket 152 is inclined while being slid, thereby adjusting forward and backward tilting. Here, the movable bracket 152 slides because the guide rail 141a is coupled to the guide groove 142a.

On the other hand, when the tightening bolt 153 is turned in the opposite direction to the arrow, the tightening bolt 153 screwed to the fixing bracket 151 is reversed, and the movable bracket 152 by the elastic restoring force of the elastic member 154. In the elastically supported state, the movable bracket 152 is inclined in the opposite direction, the forward and backward tilting is adjusted.

After the tilting of the left and right, front and rear directions is adjusted, the locking unit 160 is operated to fix the adjusted front, rear, left and right tilting.

Through such a series of left and right, front and rear tilting adjustment process, it is possible to prevent contact failure between the circuit printed on the substrate B and the semiconductor chip in advance.

As described above, in the detailed description of the present invention has been described with respect to preferred embodiments of the present invention, those skilled in the art to which the present invention pertains various modifications can be made without departing from the scope of the present invention Of course.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below, but also by the equivalents of the claims.

1 is a graph showing the contact force in conventional chip bonding

2 is a perspective view showing a chip bonder of the present invention;

3 is an exploded perspective view showing a first unit in the chip bonder of the present invention;

4 and 5 are side views illustrating left and right tilting adjustment in the first unit of the present invention.

6 and 7 are side views illustrating the forward and backward tilting adjustment in the first unit of the present invention.

* Description of main parts

100: first unit

200: second unit

110: base block

120: left and right tilting control block

121: fixed block

121a: guide rail

122: tilting block

122a: guide groove

130: left and right tilting adjustment unit

131: fixing bracket

132: movable bracket

133: tightening bolt

134: elastic member

135: Support Bolt

136: auxiliary spring

140: forward and backward tilting control block

141: fixed block

142: tilting block

141a: guide rail

142a: guide groove

150: front and rear tilting adjustment unit

151: fixing bracket

152: movable bracket

153: Tightening bolt

154: elastic member

155: Support Bolt

156: auxiliary spring

160: locking section

B: Substrate

170: stage

171: anti-rotation groove

180: load cell bracket

182: anti-rotation protrusion

210: head block

220: laser beam irradiation unit

Claims (7)

A first unit capable of tilting in front and rear and left and right directions and having a substrate seated on an upper surface thereof; And Located above the first unit, including a second unit for sucking and transporting the semiconductor chip, The first unit includes a base block; A left and right tilting control block mounted on the upper portion of the base block in such a way as to be tiltable in a horizontal direction; Left and right tilting control unit for adjusting the tilting of the left and right tilting control block; A front and rear direction tilting control block mounted on the top of the left and right tilting control block so as to be tiltable in the front and rear directions; Front and rear tilting control unit for adjusting the tilting of the front and rear tilting control block; Locking unit for fixing the tilting of the front and rear left and right tilting control block; And a stage on which the substrate is seated. delete The method of claim 1, Chip bonder, characterized in that the load cell bracket having a load cell is installed below the stage. The method of claim 3, A chip bonder, characterized in that the anti-rotation projection is formed on the upper surface of the load cell bracket, the anti-rotation groove corresponding to the anti-rotation projection is formed on the lower surface of the stage. The method of claim 1, The left and right tilting control block and the front and rear tilting control block is composed of a fixed block, and a tilting block which is installed to be able to tilt in the left and right directions with respect to the fixed block, A guide rail is formed on an upper surface of the fixed block, and a guide groove is formed on a lower surface of the tilting block. The left and right direction adjustment portion and the front and rear direction adjustment portion fixed to one side of the fixing block; A movable bracket fixed to one side of the tilting block; A tightening bolt fixed to one side of the fixing bracket to move the movable bracket; An elastic member installed at the other side of the fixing bracket to support the movable bracket; And Chip bonder comprising a support bolt for supporting the elastic member. The method of claim 1, The stage bonder, characterized in that the heater block. The method of claim 1, The second unit A head block for sucking and lifting a semiconductor chip on a lower surface thereof; And And a laser beam irradiation unit disposed above the head block to bond the semiconductor chip to the substrate.

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