JP3436116B2 - Heat block for eutectic bonding of electronic components - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat block for eutectic bonding of electronic components for eutectic bonding of electronic components to a substrate. 2. Description of the Related Art As a method of mounting an electronic component on a substrate,
Eutectic bonding is known. In eutectic bonding, a substrate is placed on a heat block and heated to a eutectic temperature, and electronic components are pressed to perform eutectic bonding. The heat block is made of steel and has a built-in heater inside. [0003] FIG. 7 (a) is a side view of a first conventional heat block. Two heaters 2 are built in the heat block 1A. Guide portions 3 are provided on both sides of the upper surface of the heat block 1A so as to protrude.
The upper surface of the shallow groove between them constitutes the mounting portion 4 of the substrate 7. A temperature sensor 5 such as a thermocouple is embedded immediately below the mounting section 4. The heater 2 and the temperature sensor 5 are connected to a controller 6. The temperature of the mounting section 4 is detected by the temperature sensor 5, and while the detection result is fed back to the controller 6, the controller 6 controls the heater 2 to maintain the mounting section 4 at an optimum temperature. The substrate 7 is placed on the receiver 4
The electronic component 8 is heated by the heat transfer of the heat block 1A, and the eutectic bonding of the electronic component 8 is performed. [0004] However, the first conventional example has an advantage that the heater 2 can be rapidly heated because the heater 2 is provided at a very short distance from the mounting portion 4, but the temperature distribution of the mounting portion 4 can be increased. As shown in the figure, there is a problem that the temperature ta varies and the temperature varies locally. [0005] FIG. 7 (b) is a side view of a second conventional heat block. The heat block 1B is formed to be quite thick, and the heater 2 is built in a position far away from the mounting portion 4. Therefore, the heat H of the heater 2 is uniformed in the heat block 1B while being transmitted to the mounting portion 4, so that the substrate 7 can be uniformly heated as indicated by the temperature distribution tb. However, in this case, since the heater 2 is far away from the receiver 4, the temperature is detected by the temperature sensor 5 and fed back to the controller 6, and the controller 6 controls the heater 2 to reduce the temperature of the receiver 4. It takes a considerable amount of time to reach the appropriate temperature.
However, there is a problem that the responsiveness of the temperature control is poor. [0006] FIG. 7 (c) is a side view of a third conventional heat block. A large number of heaters 2 are built in the heat block 1 </ b> C immediately below the mounting section 4. Therefore, this has an advantage that the temperature of the mounting portion 4 can be made substantially uniform, as shown by the temperature distribution tc. However, since a large number of heaters 2, temperature sensors 5, and controllers 6 are provided, there is a problem that the cost is increased. Note FIG. 7 (b), is omitted controller 6 in (c). [0007] Accordingly, the present invention provides
An object of the present invention is to provide a heat block for eutectic bonding of electronic components, which can optimally control the temperature of a mounting portion of a substrate with a small number of heaters. [0008] A heat block according to the present invention comprises a steel first block having a built-in heater, and a first block.
A second block made of a metal having higher thermal conductivity than the first block provided on the first block, and a third block made of steel having a substrate mounting portion on the second block.
A lock is provided , and the second block is connected to the third block.
It was formed in the recess of the block . According to this structure, since the thermal conductivity of the second block is high, the entire second block is rapidly and uniformly heated to a high temperature by the heat transfer from the first block . In addition, heat transfer from the second block
Click is Ru are and uniformly heated or fast. Then, the substrate placed on the placement section is uniformly heated to the eutectic temperature by the third block. (Embodiment 1) FIG. 1 is an overall perspective view of an electronic component eutectic bonding apparatus according to Embodiment 1 of the present invention, FIG. 2 is a perspective view of the same heat block, and FIG. FIG. 4 is an exploded perspective view of the heat block, FIG. 4 is a side view of the heat block, and FIG. 5 is an explanatory diagram of heat conduction of the heat block. First, an overall structure of an electronic component eutectic bonding apparatus will be described with reference to FIG. In the electronic component eutectic bonding apparatus, a plurality (six in this example) of heat blocks 30 are linearly arranged. The central heat block 30 is mounted on a movable table 13 including an X table 11 and a Y table 12. The substrate 7 is transported on the upper surface of each heat block 30. A stocker 14 is provided on the upstream side of the transport path of the substrate 7 constituted by the heat block 30.
The substrates 7 are stacked and stored in the stocker 14. A magazine 15 is provided downstream of the transport path for collecting the substrate 7 on which the eutectic bonding of electronic components has been completed. A table 17 provided with a wafer 15 and a position regulating claw 16 is provided on one side of the movable table 13. Reference numeral 18 denotes a transfer head, which picks up the electronic component 8 of the wafer 15 by vacuum suction with a nozzle 19 and transfers the electronic component 8 onto the table 17. The position restricting claw 16 is pressed against the electronic component 8 transferred on the table 17, and the positional deviation is corrected. Table 17 with misalignment corrected
The upper electronic component 8 is the nozzle 2 of the bonding head 20.
1 and is picked up by the vacuum
The substrate is transferred to the substrate 7 placed on the upper heat block 30 and subjected to eutectic bonding. The movable table 13
Adjusts the position of the substrate 7 in the X and Y directions. On the other side of the movable table 13, a supply unit 22 for a gold preform is provided. Reference numeral 23 denotes a gold tape derived from the supply unit 22. The gold tape 23 is a gold tape piece 2 according to the size of the electronic component 8.
It is cut into 3a. The cut gold tape piece 23a is vacuum-adsorbed to the nozzle 25 of the head 24 and is picked up.
It is transferred to the substrate 7. The bonding head 20 mounts the electronic component 8 on the gold tape piece 23a. Numeral 26 denotes a substrate transport head, which picks up the substrates 7 provided in the stocker 14 by vacuum suction one by one with suction pads 27, and picks up the most upstream (left side in FIG. 1) heat block 30. Transfer to the top. A first transfer claw 28 and a second transfer claw 29 are provided on a side portion of the heat block 30.
Is pitch-fed toward the magazine 15. The temperature of each heat block 30 is 200 ° C., 300 °
C, 400 ° C, 450 ° C, 300 ° C, 200 ° C
It is. Eutectic bonding temperature of electronic component 8 is 450 °
C, the substrate 7 is gradually heated while transporting the substrate 7 on the heat block 30. When the eutectic bonding is completed on the heat block 30 on the movable table 13, the magazine 15 is gradually reduced while the temperature of the substrate 7 is gradually reduced. To be collected. Next, the structure of the heat block 30 will be described with reference to FIGS. The heat block 30 is formed by stacking a first block 31, a second block 32, and a third block 33, and connecting them by screws 34 so as to be separable.
The first block 31 is made of steel, and has a plurality (two in this example) of heaters 35 built therein. Second
The block 32 is much thinner than the first block 31 and is made of a metal having a higher thermal conductivity than the first block 31, such as copper. The second block 32 is mounted on the first block 31 by surface bonding, and the heat transfer from the first block 31 is transmitted to the entire lower surface of the second block 32. The third block 33 is made of steel, and has guide portions 36 projecting from both sides thereof. The upper surface of the shallow groove between the guide portion 36 and the guide portion 36
It is seven. The third block 33 contains a temperature sensor 38 such as a thermocouple. The temperature sensor 38 is provided right above the heater 35. 4, the temperature sensor 38 and the heater 35 are connected to a controller 39. The temperature of the mounting section 37 is detected by a temperature sensor 38, and the detection result is input to a controller 39. The controller 39 controls the driving of the heater 35 based on the detected temperature. This electronic component eutectic bonding apparatus is constructed as described above, and the overall operation will be described next. In FIG. 1, the substrate 7 of the stocker 14 is picked up by the head unit 26, and the first heat block 3 in the uppermost stream.
Transferred to 0. The substrate 7 transferred onto the heat block 30 is sequentially sent to the second heat block 30 and the third heat block 30 by the transport claws 28,
Further, it is sent onto the fourth (bonding position) heat block 30 on the movable table 13. In the meantime, the substrate 7 is gradually heated by each heat block 30, and the eutectic temperature (4
50 ° C). The nozzle 25 of the head 24 is connected to the supply unit 2
The second gold tape piece 23a is picked up and mounted on the substrate 7 at a predetermined coordinate position. The transfer head 18 is used for the wafer 1
The electronic component 8 of FIG.
6 corrects the displacement of the electronic component 8. The electronic component 8 whose positional deviation has been corrected is picked up by the nozzle 21 of the bonding head 20, and the gold tape piece 23 of the substrate 7 is
a and is pressed against the substrate 7, whereby the electronic component 8 is eutectic bonded to the substrate 7. The substrate 7 on which the eutectic bonding has been completed is transported on the fifth and sixth heat blocks 30 by the transport claws 29 and collected in the magazine 15. Meanwhile, the substrate 7 is gradually cooled. FIG. 5 shows how the heat block 30 conducts heat. The second block 32 is heated by the heat transfer H1 from the first block 31. Since the second block 32 has high thermal conductivity and the lower surface of the second block 32 is surface-bonded to the upper surface of the first block 31,
This heat transfer H1 is quickly transferred to the entire second block 32 (see arrow H2), and the entire second block 32 is quickly and uniformly heated to a high temperature. Then, the heat transfer H3 from the entire upper surface of the second block 32 is transmitted to the entire lower surface of the third block 33, and the entire third block 33 is quickly and uniformly heated by the heat transfer H4. Therefore, according to the heat block 30, the entire substrate 7 can be heated uniformly and efficiently, and eutectic bonding can be performed satisfactorily. td indicates the temperature distribution of the mounting portion 37, and a uniform temperature distribution can be obtained. (Embodiment 2) FIG. 6 is a sectional view of a heat block according to Embodiment 2 of the present invention. The heat block 40 includes a first block 41 made of steel, a second block 42 made of copper, and a third block 43 made of steel. The second block 42 is formed by casting copper into the recess 49 of the third block 43. 46 is a guide section,
Reference numeral 47 denotes a substrate mounting portion. The function and effect of the heat block 40 are the same as those of the first embodiment. The heat from the first block 41 heats the entire second block 42 quickly and uniformly. 42 due to heat transfer from the entire surface of
Block 43 is uniformly heated. te is the receiver 4
7 is a temperature distribution. Since the second block 42 and the third block 43 are integrally formed, the second block 4
The heat conduction from the second to the third block 43 is the same as in the first embodiment.
It is better than the heat block 30 of FIG. As described above, according to the present invention, the entire second block is quickly and uniformly heated to a high temperature by heat transfer from the first block. Heated to the second blow
The third block is fast and uniform due to heat transfer from the rack
Can be heated Runode, heated to whether the substrate placed on the placing portion uniformly and quickly to a predetermined temperature, performs better eutectic bonding electronic components. In addition, the responsiveness of temperature control is excellent due to the high thermal conductivity. Even if the number of heaters is small, the entire third block can be uniformly heated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall perspective view of an electronic component eutectic bonding apparatus according to a first embodiment of the present invention. FIG. 2 is a perspective view of a heat block according to the first embodiment of the present invention. FIG. 4 is an exploded perspective view of the heat block according to the first embodiment of the present invention. FIG. 4 is a side view of the heat block according to the first embodiment of the present invention. FIG. 6 is a sectional view of a heat block according to a second embodiment of the present invention. FIG. 7 (a) is a side view of a conventional heat block, (b) is a side view of a conventional heat block, and (c) is a side view of a conventional heat block. Side view [Description of reference numerals] 7 Board 8 Electronic components 30, 40 Heat blocks 31, 41 First blocks 32, 42 Second blocks 33, 43 Third blocks 35 Heaters 36, 46 Guide parts 37, 47 Placement Part 38 temperature sensor 3 Controller

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/60 H01L 21/52

Claims (1)

(57) [Claim 1] A heat block for eutectic bonding of electronic components, wherein the first block is made of steel and has a built-in heater.
And a second block made of metal having a higher thermal conductivity than the first block provided on the first block, and a mounting portion for the substrate is provided above the second block.
A third steel block is provided , and the second block is further provided .
A heat block for eutectic bonding of electronic components , wherein a lock is formed in a concave portion of the third block.