CN102723427B - LED wafer eutectic welding procedure - Google Patents

Abstract

The present invention discloses a kind of LED wafer eutectic welding procedure, comprises the following steps: some print scaling powder step, the welding position point print scaling powder on support to be welded; Wafer lays step, wafer to be welded is placed in point on described support and has printed the welding position of scaling powder; PULSE HEATING step, Current Heating device is utilized to pass through pulse current, described wafer is heated from top to bottom, utilizes the constant temperature heating device be placed in welding base to carry out heated at constant temperature from the bottom up to described support simultaneously, fixed bonding after described support and wafer eutectic are dissolved; Nitrogen cooling step, using nitrogen cooling device to adding the LED wafer nitrogen-blow after thermal weld, making it be cooled to normal temperature.Firing rate of the present invention is fast, welding precision is high, and the LED wafer after using this technique to weld has better thermal conductivity, reaches and reduces thermal resistance effect.

Description

LED wafer eutectic welding procedure

Technical field

The present invention relates to LED wafer encapsulation manufacturing technology, particularly relate to a kind of LED wafer eutectic welding procedure.

Background technology

Eutectic solder technology has a wide range of applications in Electronic Packaging industry, as bonding, the shell sealing cap etc. of bonding, substrate and the shell of wafer and substrate.Compared with bonding with traditional epoxy conducting, eutectic welding has the advantage that thermal conductivity is high, thermal resistance is low, heat transfer is fast, reliability is strong, adhesive strength is large, is applicable to wafer and the mutual of substrate, substrate and shell in the device such as high frequency, semiconductor and glues.

Along with the high speed development of LED technology, LED wafer encapsulation is more and more to high-power and integrated direction development, and LED wafer to welding process requirement far away higher than low-power LED wafer, traditional elargol technique for sticking has been difficult to the welding process requirement meeting LED wafer, thus, increasing great power LED manufacturer starts to attempt other more advanced welding procedures to realize the bonding of LED wafer and support, and wherein, eutectic solder technology is thought to have good application prospect by common.

But because the eutectic melting point of LED wafer is greatly about more than 300 DEG C, and the LED wafer eutectic welding procedure of prior art generally adopts hot air reflux stove to heat, this heating means firing rate is slow and to heat the maximum temperature that can reach lower.In addition, the scheme adopting infrared bonding connection technology is also had in prior art, although this scheme has thermal source to control convenient, easily to control heating-up temperature rate of climb advantage, but also there is a lot of shortcoming, as more sensitivity speck can crested, less unified heating, element and PCB quality difference to affect heating effect, the temperature difference larger etc.

Summary of the invention

Technical problem to be solved by this invention is: provide a kind of LED wafer eutectic welding procedure, this technique firing rate is fast, welding precision is high, and the LED wafer after welding can be made to have better thermal conductivity, reaches and reduces thermal resistance effect.

For solving the problems of the technologies described above, the present invention adopts following technical scheme:

A kind of LED wafer eutectic welding procedure, comprises the following steps:

Point print scaling powder step, the welding position point print scaling powder on support to be welded;

Wafer lays step, wafer to be welded is placed in point on described support and has printed the welding position of scaling powder;

PULSE HEATING step, Current Heating device is utilized to pass through pulse current, described wafer is heated from top to bottom, utilizes bracket base constant temperature heating device to carry out heated at constant temperature from the bottom up to described support simultaneously, fixed bonding after support described in it and wafer eutectic are dissolved;

Nitrogen cooling step, uses nitrogen cooling device to the LED wafer nitrogen-blow after heating, makes it be cooled to normal temperature.

Preferably, also included before described PULSE HEATING step:

First look identification step, the surface size treating welding support carries out vision identification processing, confirms the position of support to be welded, and judges support outward appearance to be welded, rejects the bad bad material in location or prompting process.

Preferably, described First look identification step specifically includes:

First optical dimensions detecting step, by be arranged on above eutectic jig optical detection camera visual identity detection is carried out to rack surface size to be welded, and take positioning image;

First image processing step, carrying out image procossing to the positioning image of described optical detection camera shooting, by utilizing the positioning image of default intermediate standard picture and shooting to contrast, calculating the locating accuracy of support to be welded;

First identifying processing step, judges the standard whether described locating accuracy reaches default if so, then to perform described heating steps, otherwise, using described support to be welded as bad material processed.

Preferably, also included before described First look identification step:

Wafer angle aligning step, carries out wafer angle correction to wafer to be welded.

Preferably, also included before described wafer angle aligning step:

First carrying wafers step, draws wafer to be welded from chip carrier, and by be corrected on this carrying wafers to wafer angle means for correcting;

Also include after described wafer angle aligning step, before described First look identification step:

Second carrying wafers step, draws from described wafer angle means for correcting and corrects complete wafer, and by this carrying wafers on eutectic jig.

Preferably, also included before described first carrying wafers step:

Second visual recognition step, uses visual identifying system to carry out vision identification processing to wafer to be handled, identifies the material of wafer to be handled.

Preferably, also included before described First look identification step:

Prop up shelf for conveying step, draw support to be handled from bracket tray, and this support is transported on eutectic jig.

Preferably, described second visual recognition step specifically includes:

Second optical dimensions detecting step, carries out visual identity detection by the optical detection camera be arranged in wafer supply unit to wafer to be handled, and takes positioning image;

Second image processing step, carries out image procossing to the positioning image of described optical detection camera shooting, identifies the material of wafer to be handled;

Second identifying processing step, judges that whether the material of described wafer is qualified, if so, then performs described first carrying wafers step, otherwise, using this wafer as bad material processed.

The invention has the beneficial effects as follows:

Embodiments of the invention heat up instantaneously by utilizing Current Heating device generation pulse current to reach, and by the heat conduction of welding suction nozzle to LED wafer surface, heated at constant temperature is adopted to frame bottom simultaneously, the welding compound of the golden tin composition of bottom of wafer and submount material eutectic are dissolved and reaches fixed bonding, by LED wafer together with support welding, realize the effect of LED wafer eutectic welding, thus the LED wafer after making welding complete has better thermal conductivity, reach the thermal resistance effect reducing product, and greatly accelerate firing rate, weld time, improve eutectic precision, production efficiency.

Embodiment

An embodiment of LED eutectic welding procedure of the present invention is described below in detail; The present embodiment realizes a LED eutectic welding process and mainly comprises the following steps:

Point print scaling powder step, the welding position point print scaling powder on support to be welded;

Wafer lays step, wafer to be welded is placed in point on described support and has printed the welding position of scaling powder;

PULSE HEATING step, Current Heating device is utilized to pass through pulse current, the constant temperature heating device heat from top to bottom described support, simultaneously utilized base to provide carries out heated at constant temperature from the bottom up to this wafer, fixed bonding after described support and wafer eutectic are dissolved;

Nitrogen cooling step, uses nitrogen cooling device to the LED wafer nitrogen-blow after heating, makes it be cooled to normal temperature.

During specific implementation, also can include before described PULSE HEATING step:

First look identification step, the surface size treating welding support carries out vision identification processing, confirms the position of support to be welded, and judges support outward appearance to be welded, rejects the bad bad material in location or prompting process.

Further, described First look identification step is seen and is specifically included:

First optical dimensions detecting step, by be arranged on above eutectic jig optical detection camera visual identity detection is carried out to rack surface size to be welded, and take positioning image;

First image processing step, carrying out image procossing to the positioning image of described optical detection camera shooting, by utilizing the positioning image of default intermediate standard picture and shooting to contrast, calculating the locating accuracy of support to be welded;

First identifying processing step, judges the standard whether described locating accuracy reaches default if so, then to perform described heating steps, otherwise, using described support to be welded as bad material processed.

In addition, also included before described First look identification step:

Wafer angle aligning step, carries out wafer angle correction to wafer to be welded.

Also included before described wafer angle aligning step:

First carrying wafers step, draws wafer to be welded from chip carrier, and by be corrected on this carrying wafers to wafer angle means for correcting;

Also include after described wafer angle aligning step, before described First look identification step:

Second carrying wafers step, draws from described wafer angle means for correcting and corrects complete wafer, and by this carrying wafers on eutectic jig.

Further, also included before described first carrying wafers step:

Second visual recognition step, uses visual identifying system to carry out vision identification processing to wafer to be handled, identifies the material of wafer to be handled.

During specific implementation, described second visual recognition step specifically includes:

Second optical dimensions detecting step, carries out visual identity detection by the optical detection camera be arranged in wafer supply unit to wafer to be handled, and takes positioning image;

Second image processing step, carries out image procossing to the positioning image of described optical detection camera shooting, identifies the material of wafer to be handled;

Second identifying processing step, judges that whether the material of described wafer is qualified, if so, then performs described first carrying wafers step, otherwise, using this wafer as bad material processed.

In addition, also included before described First look identification step:

Prop up shelf for conveying step, draw support to be handled from bracket tray, and this support is transported on eutectic jig.

The above is the preferred embodiment of the present invention; it should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention; can also make some improvements and modifications, these improvements and modifications are also considered as protection scope of the present invention.

Claims (7)

1. a LED wafer eutectic welding procedure, is characterized in that, comprises the following steps:

Point print scaling powder step, the welding position point print scaling powder on support to be welded;

Wafer lays step, wafer to be welded is placed in point on described support and has printed the welding position of scaling powder;

First look identification step, the surface size treating welding support carries out vision identification processing, confirms the position of support to be welded, and judges support outward appearance to be welded, rejects the bad bad material in location or prompting process;

PULSE HEATING step, Current Heating device is utilized to pass through pulse current, described wafer is heated from top to bottom, utilizes the constant temperature heating device be placed in welding base to carry out heated at constant temperature from the bottom up to described support simultaneously, fixed bonding after described support and wafer eutectic are dissolved;

Nitrogen cooling step, using nitrogen cooling device to adding the LED wafer nitrogen-blow after thermal weld, making it be cooled to normal temperature.

2. LED wafer eutectic welding procedure as claimed in claim 1, it is characterized in that, described First look identification step specifically includes:

First optical dimensions detecting step, by be arranged on above eutectic jig optical detection camera visual identity detection is carried out to rack surface size to be welded, and take positioning image;

First image processing step, carrying out image procossing to the positioning image of described optical detection camera shooting, by utilizing the positioning image of default intermediate standard picture and shooting to contrast, calculating the locating accuracy of support to be welded;

First identifying processing step, judges the standard whether described locating accuracy reaches default if so, then to perform described heating steps, otherwise, using described support to be welded as bad material processed.

3. LED wafer eutectic welding procedure as claimed in claim 2, is characterized in that, also included before described First look identification step:

Wafer angle aligning step, carries out wafer angle correction to wafer to be welded.

4. LED wafer eutectic welding procedure as claimed in claim 3, is characterized in that, also included before described wafer angle aligning step:

First carrying wafers step, draws wafer to be welded from chip carrier, and by be corrected on this carrying wafers to wafer angle means for correcting;

Also include after described wafer angle aligning step, before described First look identification step:

Second carrying wafers step, draws from described wafer angle means for correcting and corrects complete wafer, and by this carrying wafers on eutectic jig.

5. LED wafer eutectic welding procedure as claimed in claim 4, is characterized in that, also included before described first carrying wafers step:

Second visual recognition step, uses visual identifying system to carry out vision identification processing to wafer to be handled, identifies the material of wafer to be handled.

6. LED wafer eutectic welding procedure as claimed in claim 5, is characterized in that, also included before described First look identification step:

Prop up shelf for conveying step, draw support to be handled from bracket tray, and this support is transported on eutectic jig.

7. LED wafer eutectic welding procedure as claimed in claim 6, it is characterized in that, described second visual recognition step specifically includes:

Second optical dimensions detecting step, carries out visual identity detection by the optical detection camera be arranged in wafer supply unit to wafer to be handled, and takes positioning image;

Second image processing step, carries out image procossing to the positioning image of described optical detection camera shooting, identifies the material of wafer to be handled;

Second identifying processing step, judges that whether the material of described wafer is qualified, if so, then performs described first carrying wafers step, otherwise, using this wafer as bad material processed.