CN102221570A

CN102221570A - Method for detecting welding quality of semiconductor

Info

Publication number: CN102221570A
Application number: CN2011101318037A
Authority: CN
Inventors: 潘敏智
Original assignee: LESHAN RADIO CO Ltd
Current assignee: LESHAN RADIO CO Ltd
Priority date: 2011-05-20
Filing date: 2011-05-20
Publication date: 2011-10-19
Anticipated expiration: 2031-05-20
Also published as: CN102221570B

Abstract

The invention discloses a method for detecting the welding quality of a semiconductor. The method comprises the following steps of: applying needed current to a product to be detected by using ac current supply unit; monitoring a positive V-A characteristic curve of the product to be detected in real time by using a waveform monitoring unit to find whether the curve varies in real time; and recording time from the application of current to a moment when the V-A characteristic of the product to be detected varies by using a timing unit, wherein the time is longer, the resistance value of the ohmic contact resistance of the product is smaller and the welding quality is more reliable. By adopting the method, the ohmic contact situation of a semiconductor product after welding can be monitored effectively, and the welding quality of the product can be compared, limit by the current state of the product to be detected is avoided, and testing can be finished by adopting the conventional simple long-persistence oscillograph and timer.

Description

Semiconductor welding quality detection method

Technical field

The invention belongs to semiconductor, particularly relate to a kind of semiconductor welding quality detection method.

Background technology

Present semiconductor welding quality detects following several mode:

1, mechanical system is inferred chip and framework welding position;

2, well whether, relatively infer the silicon of face and alloy area, area ratio and judge whether welding is good the face of weld Ohmic contact;

Adopt above judgment mode, can't judge accurately whether the welding of product good, and this detection method is time-consuming, bothersome, not easy to operate.In addition, encapsulation back product can't detect, because plastic-sealed body seals product, even if the forms that also cause product of uncapping etc. morph, and the definite characteristic of surface product.

Summary of the invention

Fundamental purpose of the present invention is at above-mentioned problems of the prior art, provide a kind of detection simply, semiconductor welding quality detection method accurately and effectively.

In order to realize the foregoing invention purpose, the technical solution used in the present invention is as follows: a kind of semiconductor welding product

Quality inspection survey method, 1), the given unit of electric current applies the electric current that needs on product to be measured detection method is:; 2), the real-time forward V-A family curve of monitoring product to be measured of waveform monitoring unit, find curve in real time

Whether morph; 3), the timing unit record begins to become to the forward V-A family curve of product to be measured from applying electric current

The different time, if the variation time more than or equal to setting value, product then to be measured is certified products, if the variation

Time, product then to be measured was a unacceptable product less than setting value.Be timing unit record from apply electric current begin to

The time that forward V-the A characteristic curve morphs of product to be measured, ohm of long more surface product of time connects

The resistance of electric shock resistance is more little, and welding quality is reliable more.

Compared with prior art, the invention has the beneficial effects as follows: the present invention adopts simple equipment,

Ohmic contact after double conductor welding whether test, analyze and judge by good mechanical.It has the following advantages:

1, can effectively monitor Ohmic contact situation after the welding of semiconductor product, the welding quality of comparative product;

2, do not needed the current state of testing product to limit;

3, adopt existing, simply long sunset glow oscillograph and timer can finish test.

Description of drawings

Fig. 1 is a circuit diagram of realizing semiconductor welding quality detection method;

Fig. 2 is normal semiconductor forward V-A curve;

Fig. 3 is the semiconductor forward V-A curve after the variation.

Embodiment

Below in conjunction with embodiment foregoing invention content of the present invention is described in further detail.

But this should be interpreted as that the scope of the above-mentioned theme of the present invention only limits to following embodiment.Not breaking away under the above-mentioned technological thought situation of the present invention, according to ordinary skill knowledge and customary means, make various replacements and change, all should comprise within the scope of the invention.

See shown in Figure 1, semiconductor welding quality testing circuit by the given unit of electric current, waveform monitoring unit,

Timing unit, product to be measured (semiconductor) constitute, wherein, end after given unit of electric current and waveform monitoring unit are connected in parallel is connected on product to be measured (semiconductor) positive pole, and the given unit of electric current is connected with product to be measured (semiconductor) negative pole through timing unit with the other end after the waveform monitoring unit is connected in parallel.Semiconductor welding quality testing circuit realizes that the semiconductor welding quality detects, and this detection method is:

1), the given unit of electric current applies the electric current of needs on product to be measured.The given unit of electric current applies the different electric currents of product needed, and present miniwatt product is generally applied the electric current of 1.2A on product to be measured; 2), the real-time forward V-A family curve of monitoring product to be measured of waveform monitoring unit, find curve in real time

Whether morph;

3), the timing unit record begins to become to the forward V-A family curve of product to be measured from applying electric current

The time that the forward V-A family curve of product to be measured morphs, ohm of long more surface product of variation time

The resistance of contact resistance is more little, and welding quality is reliable more.Present miniwatt product setting value is 20 seconds,

Timing unit record from apply electric current begin to the forward V-A family curve of product to be measured morph the time

Between, if the variation time more than or equal to 20 seconds, product then to be measured is certified products, if the variation time is little

In 20 seconds, product then to be measured was a unacceptable product.Begin forward V-A spy from applying electric current to product to be measured

The time that linearity curve morphs, the resistance of the ohmic contact resistance of surface product was at this moment when being 20 seconds

0.0000002 ohm.The resistance of the ohmic contact resistance of surface product is that normal Ohmic contact exists

0.0000002 ohm, unusual may reach about 1 ohm.

Its principle of work of the present invention is, the V-A characteristic of semiconductor product is relevant with temperature, and temperature is high more, V-A

Curvilinear motion is big more, and temperature depends on the heating of product, cause electric current that the energy of this heating equals to apply square * ohmic contact resistance * the apply time of electric current.

Among the present invention, the given unit of electric current can adopt existing conventional DC constant-current supply, the product size of current that can detect as required of choosing of this power supply is chosen, and generally selects for use principle at 5～10 times, and promptly the given current maxima of direct supply equals 5～10 times of product rated current.The waveform monitoring unit can adopt long sunset glow oscillograph, and timing unit can adopt timer.Because of its welding quality difference, all there is a different Ohmic contact in all products to be measured, and a different Ohmage value is promptly arranged, and this detection method is exactly poor more according to welding quality, and the characteristic that the resistance of ohmic contact resistance is big is more carried out;

In the testing process, semiconductor product is added on oscillographic EC two ends, applies the forward half-wave current of 1.2A; Pick up counting when adding electric current; Timing finishes when waveform becomes Fig. 3 by Fig. 2.

The institute's time-consuming that compares different product, the product that the consumption time is long, its Ohmic contact is better, and welding quality is high more.

Determining of variation time set value: when will be as a criterion, need carry out group experiment to product, collect different grouping test time corresponding, draw different averaging times by normal distribution analysis, determine a rational setting value according to different mean value at last the time.Specific embodiments is as follows:

1, gets the sample of some, the production of certain hour section; 2, bring respectively and do this detection, the record variation time; 3, the time is carried out data analysis as one group of data; 4, analyze the back and set acceptance line (setting value); 5, this acceptance line (setting value) is promptly worked as the product that later production line is produced as a foundation of product in producing after differentiating, and the variation time is then defective less than this acceptance line (setting value).Normal Ohmic contact is at 0.0000002 ohm, and unusual may reach about 1 ohm.

During concrete the detection, embodiment is:

1, adopts long sunset glow oscillograph, product is applied the semi-wave DC of about 1.2A;

2, long sunset glow oscillograph is monitored the forward V-A family curve of product to be measured in real time, finds bent in real time

Whether line morphs;

3, adopt simple timer, apply from electric current and pick up counting, finish to the curve waveform timing of morphing;

4, under the more different welding manners, the length of product tolerance time (variation time), its welding back Ohmic contact of the product of time length is more good.

Claims

1. semiconductor welding quality detection method is characterized in that detection method is:

1), the given unit of electric current applies the electric current of needs on product to be measured;

2), the real-time forward V-A family curve of monitoring product to be measured of waveform monitoring unit, find in real time whether curve morphs;

3), timing unit record begins time of morphing to the forward V-A family curve of product to be measured from applying electric current, if the variation time is more than or equal to setting value, product then to be measured is certified products, if the variation time less than setting value, product then to be measured is a unacceptable product.