CA1255014A - Round solder pad for surface mounting electronic devices and a surface mounting position incorporating such shaped pads - Google Patents
Round solder pad for surface mounting electronic devices and a surface mounting position incorporating such shaped padsInfo
- Publication number
- CA1255014A CA1255014A CA000534145A CA534145A CA1255014A CA 1255014 A CA1255014 A CA 1255014A CA 000534145 A CA000534145 A CA 000534145A CA 534145 A CA534145 A CA 534145A CA 1255014 A CA1255014 A CA 1255014A
- Authority
- CA
- Canada
- Prior art keywords
- solder
- circuit board
- printed circuit
- pad
- pads
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/30—Assembling printed circuits with electric components, e.g. with resistor
- H05K3/32—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
- H05K3/34—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
- H05K3/341—Surface mounted components
- H05K3/3421—Leaded components
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/02—Details
- H05K1/11—Printed elements for providing electric connections to or between printed circuits
- H05K1/111—Pads for surface mounting, e.g. lay-out
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
- H05K2201/09—Shape and layout
- H05K2201/09209—Shape and layout details of conductors
- H05K2201/09372—Pads and lands
- H05K2201/0939—Curved pads, e.g. semi-circular or elliptical pads or lands
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
- H05K2201/10—Details of components or other objects attached to or integrated in a printed circuit board
- H05K2201/10007—Types of components
- H05K2201/10166—Transistor
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
- H05K2203/04—Soldering or other types of metallurgic bonding
- H05K2203/048—Self-alignment during soldering; Terminals, pads or shape of solder adapted therefor
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
- H05K2203/15—Position of the PCB during processing
- H05K2203/1572—Processing both sides of a PCB by the same process; Providing a similar arrangement of components on both sides; Making interlayer connections from two sides
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/30—Assembling printed circuits with electric components, e.g. with resistor
- H05K3/32—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
- H05K3/34—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
- H05K3/341—Surface mounted components
- H05K3/3415—Surface mounted components on both sides of the substrate or combined with lead-in-hole components
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Abstract
A ROUND SOLDER PAD FOR SURFACE MOUNTING ELECTRONIC DEVICES AND A
SURFACE MOUNTING POSITION INCORPORATING SUCH SHAPED PADS
Astract of the Disclosure Solder pads for the surface mounting of devices on a circuit board are given a round shape of predetermined size, By such shaping of a solder pad, or contact pad, a device will be held in, or moved to, a desired position on the melting of the solder at the pad.
Improved alignment and positioning is obtained.
- i -
SURFACE MOUNTING POSITION INCORPORATING SUCH SHAPED PADS
Astract of the Disclosure Solder pads for the surface mounting of devices on a circuit board are given a round shape of predetermined size, By such shaping of a solder pad, or contact pad, a device will be held in, or moved to, a desired position on the melting of the solder at the pad.
Improved alignment and positioning is obtained.
- i -
Description
~.25i5~
A ROUND SOLDER PAD FOR SURFACE MOURTING ELECTRONIC DEVICES AND A
SURFACE MOUNTING POS~TION INCORPORATING SUCH SHAPED PADS
This invention relates generally to solder pads, for surface mounted devices, and more particularly relates to a specific shaping and slzing of such pads. A feature of the invent-ion is the ability to hold devices in place, on or under the surface of a circuit board, duriny soldering of further devices on the obverse of the circuit board.
~ackground of the Invention A very large proportion of electronic devices are surface mounted on circuit boards. In such a process, a circuit pattern is defined on a circuit board, usually in copper, the copper pattern being afterwards tinned, to assist soldering amongst other reasons~ Such circuit boards are generally referred to as printed circuit boards (PCB). In the circuit pattern, lands (or pads) are defined, to which devices are to be soldered. The land sizes, and spacing, depend generally on the size of device to be mounted. Two lands may be provided for a device which is to be connected at each end. A patkern of lands may be provided ~For connection of leads, or contact pads, of encapsulated devices.
For good electrical connectiorl it is desired that a device be centered upon the lands. Centering is also desirable to ensure satisfactory spacing of the devices, one to another. With conventional forms of circuit pattern, the contact pads for devices are usually rectangular. Although devices may be positioned so as to be aligned correctly~ and are central on the contact pads, they can move prior to soldering. Posltioning of the devices may also not be accurate and m~salignment and o-ff-center posi-tioning occur, ~L 2 S S~D~L~
Soldering itself may also cause devices to move from the desired position.
Prior patents which relate generally to soldering systems and to which attention is directed are as follows: U.S.
patent 4,127,692 dated November 28, 1978 by K.G. Boynton; U.S. patent 4,39~,660 dated August 16, 1983 by T.R. Pampalone et al; and U.S.
patent 4,~45,114 dated February 24, 1987 by Jacques Van Den Brekel, Carlyle W. Crothers, and Dale B. Squires.
Summarv of the Invention The present invention is concerned with the specific shaping of contact pads. By suitable shaping of a contact pad, a device can be held in a desired position or moved to the desired position is mispositioned, on the melting of the solder at the contact pads, during soldering. Substantial improvement in alignment and positioning is thereby obtained. Broadly, in accordance with the present invention, a contact pad comprises a body having a deflned shape and size; the shape being square with rounded corners and at the limit being round and having a diameter of between 0.058 inches and 0.064 inches.
A further feature to which the present invention can also be applied, is the holding in positio~ of devices on an undersurface of a circuit board, during reflow soldering of further devices on the obverse of the circuit board. By providing a predetermined amsunt of solder, related to the weight of the device, the device will stay in position on the undersurface even though the soldering attaching it is molten.
Stated in other terms, the present invention is a solder pad on a printed circuit board for the mounting by soldering of ~2~ L~L
surface mounted devices to a printed circuit board to thereby establish both electrical contact to, and mechanical connection to, the printed circuit board, the solder pad being characterized by being approximately circular in shape.
Stated in yet other terms, the present invention is a solder mounting position both for mechanically attaching a surface mounted electronic component to a printed circuit board, and for establishing electrical conta~t to conductors on said printed circuit board, each said position characterized by: a plurality of solder pads spaced in a predetermined pattern to facilitate alignment of surface mounted components, each said solder pad being defined by an approximately circular shape; wherein said plurality of solder pads are three ;n number and positioned so as to form approx;mately an equilateral triangle.
Brief Description of the Drawinqs The invention w;ll be readily understood by the following description of certain embodiments, by way of example, in conjunction with the accompanying diagrammatic drawings, in wh;ch:
Figure 1 is a plan view of a surface mounted device;
Figure 2 is an elevational view of the device of Figure 1, taken along the section lines 2-2 of Figure l;
Figure 3 is an end view of the device of Figure 1, taken along the section lines 3-3 of Figure l; and Figure 4 is a plan view of the device of Figure 1, additionally depicting solder pads for the mounting of the device.
Detailed DescriPtion Figures 1, 2 and 3 illustrate a typical electronic device or component 10, which is rectangular in plan form, usually ~L~ 5C~L~
elongate, and is usually rectangular in cross-section viewed from an end. Component 10 has three Formed leads 11 protruding from the longer sides, such that there are two leads 11 on one side and one lead 11 on the other, midway between the two leads 11 on the opposite side. One example of component 10 is a small outline transistor (SOT) 3a ~2~ii5c~
such as a model MM~T390~ rnanufactured by Motorola.
Figure 4 illustrates a typical mounting position having three contact pads 12 spaced apart. Each pad 12 has a circular shape with a diameter of approximately 0.062 inches. The tinned contact 5 portions of leads 11 of the device 10 are positioned on the round pads 12, as shown in Figure 4.
The action of the round contact pad 12 is to centralize the leads 11 of the device or component 10 during soldering. The process for the mounting of components is generally as follows, although variations in the specific process can occur:
1) The circuit board has a circuit pattern defined on one or both surfaces - this is done by conventional means, such as by photolithographic etching;
A ROUND SOLDER PAD FOR SURFACE MOURTING ELECTRONIC DEVICES AND A
SURFACE MOUNTING POS~TION INCORPORATING SUCH SHAPED PADS
This invention relates generally to solder pads, for surface mounted devices, and more particularly relates to a specific shaping and slzing of such pads. A feature of the invent-ion is the ability to hold devices in place, on or under the surface of a circuit board, duriny soldering of further devices on the obverse of the circuit board.
~ackground of the Invention A very large proportion of electronic devices are surface mounted on circuit boards. In such a process, a circuit pattern is defined on a circuit board, usually in copper, the copper pattern being afterwards tinned, to assist soldering amongst other reasons~ Such circuit boards are generally referred to as printed circuit boards (PCB). In the circuit pattern, lands (or pads) are defined, to which devices are to be soldered. The land sizes, and spacing, depend generally on the size of device to be mounted. Two lands may be provided for a device which is to be connected at each end. A patkern of lands may be provided ~For connection of leads, or contact pads, of encapsulated devices.
For good electrical connectiorl it is desired that a device be centered upon the lands. Centering is also desirable to ensure satisfactory spacing of the devices, one to another. With conventional forms of circuit pattern, the contact pads for devices are usually rectangular. Although devices may be positioned so as to be aligned correctly~ and are central on the contact pads, they can move prior to soldering. Posltioning of the devices may also not be accurate and m~salignment and o-ff-center posi-tioning occur, ~L 2 S S~D~L~
Soldering itself may also cause devices to move from the desired position.
Prior patents which relate generally to soldering systems and to which attention is directed are as follows: U.S.
patent 4,127,692 dated November 28, 1978 by K.G. Boynton; U.S. patent 4,39~,660 dated August 16, 1983 by T.R. Pampalone et al; and U.S.
patent 4,~45,114 dated February 24, 1987 by Jacques Van Den Brekel, Carlyle W. Crothers, and Dale B. Squires.
Summarv of the Invention The present invention is concerned with the specific shaping of contact pads. By suitable shaping of a contact pad, a device can be held in a desired position or moved to the desired position is mispositioned, on the melting of the solder at the contact pads, during soldering. Substantial improvement in alignment and positioning is thereby obtained. Broadly, in accordance with the present invention, a contact pad comprises a body having a deflned shape and size; the shape being square with rounded corners and at the limit being round and having a diameter of between 0.058 inches and 0.064 inches.
A further feature to which the present invention can also be applied, is the holding in positio~ of devices on an undersurface of a circuit board, during reflow soldering of further devices on the obverse of the circuit board. By providing a predetermined amsunt of solder, related to the weight of the device, the device will stay in position on the undersurface even though the soldering attaching it is molten.
Stated in other terms, the present invention is a solder pad on a printed circuit board for the mounting by soldering of ~2~ L~L
surface mounted devices to a printed circuit board to thereby establish both electrical contact to, and mechanical connection to, the printed circuit board, the solder pad being characterized by being approximately circular in shape.
Stated in yet other terms, the present invention is a solder mounting position both for mechanically attaching a surface mounted electronic component to a printed circuit board, and for establishing electrical conta~t to conductors on said printed circuit board, each said position characterized by: a plurality of solder pads spaced in a predetermined pattern to facilitate alignment of surface mounted components, each said solder pad being defined by an approximately circular shape; wherein said plurality of solder pads are three ;n number and positioned so as to form approx;mately an equilateral triangle.
Brief Description of the Drawinqs The invention w;ll be readily understood by the following description of certain embodiments, by way of example, in conjunction with the accompanying diagrammatic drawings, in wh;ch:
Figure 1 is a plan view of a surface mounted device;
Figure 2 is an elevational view of the device of Figure 1, taken along the section lines 2-2 of Figure l;
Figure 3 is an end view of the device of Figure 1, taken along the section lines 3-3 of Figure l; and Figure 4 is a plan view of the device of Figure 1, additionally depicting solder pads for the mounting of the device.
Detailed DescriPtion Figures 1, 2 and 3 illustrate a typical electronic device or component 10, which is rectangular in plan form, usually ~L~ 5C~L~
elongate, and is usually rectangular in cross-section viewed from an end. Component 10 has three Formed leads 11 protruding from the longer sides, such that there are two leads 11 on one side and one lead 11 on the other, midway between the two leads 11 on the opposite side. One example of component 10 is a small outline transistor (SOT) 3a ~2~ii5c~
such as a model MM~T390~ rnanufactured by Motorola.
Figure 4 illustrates a typical mounting position having three contact pads 12 spaced apart. Each pad 12 has a circular shape with a diameter of approximately 0.062 inches. The tinned contact 5 portions of leads 11 of the device 10 are positioned on the round pads 12, as shown in Figure 4.
The action of the round contact pad 12 is to centralize the leads 11 of the device or component 10 during soldering. The process for the mounting of components is generally as follows, although variations in the specific process can occur:
1) The circuit board has a circuit pattern defined on one or both surfaces - this is done by conventional means, such as by photolithographic etching;
2) The circuit pattern - generally of copper - is tin plated, this can comprise several steps including a thin copper plating before the tin plating, and is conventional;
3) Solder paste (flux and solder particles) is applied, as by screen printing or dot transfer deposition,
4) After step 3, the circuit board has a pattern of solder pads arranged in the form of an equilateral triangle, as in Figure 4. A device 10 is then positioned on the circuit board at the desired positions. The devices 10 are kept in place by the flux in the deposited solder paste, the flux acting as an adhesive;
5) The solder paste is melted by heating the circuit board by lnfrared radlation to fusion temperature - generally referred to as reflow soldering - a conventional step or process.
Once the solder has melted, then the shape of a pad 12 acts to pull the leads 11, or contact point, o-f the device 10 into a ~L~55CI~
central position. The solder on the pad, when molten, because of surface tension, tends to move the related leads 11 of the device 10 into alignment w~th the center or focus of -the round pad 12. The center, or focus, is generally on or close to the geometric center oF
the pad 12. The equilateral triangular positioning of the round pads 12 tends to centralize the device. Again, this occurs because of the surface tension in the molten solder at the pads 12. The surface tension will be equalized when each of the three leads 11 and hence the device 10 itself is symmetrical relative to the focus of each round pad 12.
The distance between the centres of round pads 12 -(D and E in Figure 4) - is generally equal to the relative centre positions of the leads 11~
A further feature of the invention is the ability to hold devices in position while the board is reversed, that is with surface mounted devices 10 on the undersurface, while reflow soldering further devices on the top surface. The devices 10 on the bottom surface are held in place, even though the solder is molten.
The disclosed pad arrangement is applicable to packages of the form SOT-23 and T0236.
The size of the pads 12 is of course a factor of the size of component 10 and its leads 11. The amount of solder paste applied to the pads 12 is important; it has been found that the preferred ratio of solder paste to pad area is 0.81 milligrams to ~5 1 square millimeter. The preferred ratio of the solder paste is 99~1 parts solder to 0.1 parts flux by weight. One example of a commercial solder paste suitable for this application is part No.
255-EM manufactured by Qualitek.
Once the solder has melted, then the shape of a pad 12 acts to pull the leads 11, or contact point, o-f the device 10 into a ~L~55CI~
central position. The solder on the pad, when molten, because of surface tension, tends to move the related leads 11 of the device 10 into alignment w~th the center or focus of -the round pad 12. The center, or focus, is generally on or close to the geometric center oF
the pad 12. The equilateral triangular positioning of the round pads 12 tends to centralize the device. Again, this occurs because of the surface tension in the molten solder at the pads 12. The surface tension will be equalized when each of the three leads 11 and hence the device 10 itself is symmetrical relative to the focus of each round pad 12.
The distance between the centres of round pads 12 -(D and E in Figure 4) - is generally equal to the relative centre positions of the leads 11~
A further feature of the invention is the ability to hold devices in position while the board is reversed, that is with surface mounted devices 10 on the undersurface, while reflow soldering further devices on the top surface. The devices 10 on the bottom surface are held in place, even though the solder is molten.
The disclosed pad arrangement is applicable to packages of the form SOT-23 and T0236.
The size of the pads 12 is of course a factor of the size of component 10 and its leads 11. The amount of solder paste applied to the pads 12 is important; it has been found that the preferred ratio of solder paste to pad area is 0.81 milligrams to ~5 1 square millimeter. The preferred ratio of the solder paste is 99~1 parts solder to 0.1 parts flux by weight. One example of a commercial solder paste suitable for this application is part No.
255-EM manufactured by Qualitek.
Claims (6)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A solder pad fixed to a printed circuit board for the mounting, by soldering, of surface mounted devices to said printed circuit board to thereby establish both electrical contact to, and mechanical connection to, said printed circuit board, said solder pad being characterized by being approximately circular in shape and having a solid surface area with no openings.
2. The solder pad of claim 1 further including solder paste, the ratio of said solder past to the area of said pad being approximately 0.81 milligrams of said paste to 1 square millimeter of said pad area to provide a tension sufficient for holding said devices while said printed circuit board is inverted and said solder paste is in a molten state.
3. A solder mounting position both for mechanically attaching a surface mounted electronic component to a printed circuit board and for establishing electrical contact to conductors on said printed circuit board, each said position characterized by:
a plurality of solder pads space in a predetermined pattern to facilitate alignment of surface mounted components, each said solder pad being defined by an approximately circular shape and having a solid surface area with no openings.
a plurality of solder pads space in a predetermined pattern to facilitate alignment of surface mounted components, each said solder pad being defined by an approximately circular shape and having a solid surface area with no openings.
4. The solder mounting position of claim 3 wherein said plurality of solder pads are three in number and positioned so as to form approximately an equilateral triangle.
5. The solder mounting position of claim 4 wherein the diameter of said pads is approximately between 0.058 inches and 0.064 inches.
6. A solder mounting position on a printed circuit board (PCB) for attaching and aligning a surface mounted electronic component to said printed circuit board, and for establishing electrical contact to conductors on said printed circuit board, each said position characterized by:
three solid solder pads positioned on said printed circuit board in close proximity, one to another, so as to form approximately an equilateral triangle, each said solder pad having an approximately circular shape with a diameter approximately between 0.058 inches and 0.0654 inches; and said solder pads further including solder paste, having a ratio of solder paste to solder pad area of approximately 0.81 milligrams of said paste to 1.00 square millimeters of said pad area to provide a tension sufficient for holding said component while said PCB is inverted and said solder paste is in a molten state.
three solid solder pads positioned on said printed circuit board in close proximity, one to another, so as to form approximately an equilateral triangle, each said solder pad having an approximately circular shape with a diameter approximately between 0.058 inches and 0.0654 inches; and said solder pads further including solder paste, having a ratio of solder paste to solder pad area of approximately 0.81 milligrams of said paste to 1.00 square millimeters of said pad area to provide a tension sufficient for holding said component while said PCB is inverted and said solder paste is in a molten state.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000534145A CA1255014A (en) | 1987-04-08 | 1987-04-08 | Round solder pad for surface mounting electronic devices and a surface mounting position incorporating such shaped pads |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000534145A CA1255014A (en) | 1987-04-08 | 1987-04-08 | Round solder pad for surface mounting electronic devices and a surface mounting position incorporating such shaped pads |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1255014A true CA1255014A (en) | 1989-05-30 |
Family
ID=4135394
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000534145A Expired CA1255014A (en) | 1987-04-08 | 1987-04-08 | Round solder pad for surface mounting electronic devices and a surface mounting position incorporating such shaped pads |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1255014A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108059124A (en) * | 2016-11-08 | 2018-05-22 | 盾安美斯泰克股份有限公司 | The method that the MEMS die for welding attachment is self-aligned to installation surface |
-
1987
- 1987-04-08 CA CA000534145A patent/CA1255014A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108059124A (en) * | 2016-11-08 | 2018-05-22 | 盾安美斯泰克股份有限公司 | The method that the MEMS die for welding attachment is self-aligned to installation surface |
| CN108059124B (en) * | 2016-11-08 | 2023-03-14 | 盾安美斯泰克股份有限公司 | Method of self-aligning a solder-attached MEMS die to a mounting surface |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |